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Kinetic modelling of the adsorption of nitrates

Chemical Engineering Journal125(2006)111–117Kinetic modelling of the adsorption of nitratesby ion exchange resinM.Chabani a,A.Amrane b,∗,A.Bensmaili aa Facult´e de G´e nie des Proc´e d´e s et G´e nie M´e canique,U.S.T.H.B.BP32,El Allia,Bab ezzouar,Algeriab Equipe Chimie et Ing´e nierie des Proc´e d´e s-ENSCR/Universit´e de rennes1,UMR CNRS6226“Sciences chimiques de Rennes”,ENSCR,Campus de Beaulieu,av.du G´e n´e ral Leclerc,35700Rennes,FranceReceived21April2006;received in revised form17July2006;accepted6August2006AbstractThe capacity of ion exchange resins,Amberlite IRA400,for removal of nitrates from aqueous solution was investigated under different initial concentrations.The suitability of the Freundlich,Langmuir and Dubinin-Radushkevich adsorption models to the equilibrium data was investigated.The equilibrium data obtained in this study were found to follow Freundlich adsorption isotherm.The maximum sorption capacity was769.2mg/g at25◦C.Reversible-ﬁrst-order,intraparticle diffusion,ﬁlm diffusion and Bangham models were used toﬁt the experimental data. The adsorption of nitrates on Amberlite IRA400resin follows reversible-ﬁrst-order kinetics.The overall rate constants were estimated for different initial concentrations.Results of the intra-particle diffusion and theﬁlm diffusion models show that theﬁlm diffusion was the main rate-limiting step.The low correlation of data to the Bangham’s equation also conﬁrms that diffusion of nitrates into pores of the resin was not the only rate-controlling step.The thermodynamic constants of adsorption phenomena, H◦and S◦were found to be−26.122kJ/mol and−68.76J/mol in the range298–318K and+19.205kJ/mol and+68.76J/mol in the range318–343K,respectively.The negative values of the Gibbs free energy ( G)demonstrate the spontaneous nature of adsorption of nitrates onto Amberlite IRA400.©2006Elsevier B.V.All rights reserved.Keywords:Adsorption;Resin;Nitrates;Kinetics1.IntroductionSeveral nitrogenous compounds,including ammonia,nitrite and nitrate are frequently present in drinking water[1].Nitrates can cause several environmental problems.Nitrates and phos-phates can stimule eutrophication where pollution is caused in waterways by heavy algal growth,as they are both rate-limiting nutrients for process.A high concentration of nitrate-nitrogen in drinking water leads to the production of nitrosamine,which is related to cancer,and increases the risks of diseases such as methemoglobinemia in new-born infants[2,3].Several methods that serve to reduce nitrates in drinking water have been developed.The use of biological reactor seems to be the most promising technique in the treatment of high nitrate concentrations.However,maintaining biological processes at their optimum conditions is difﬁcult,and the problems of con-∗Corresponding author.Tel.:+33223235755;fax:+33223238120.E-mail address:abdeltif.amrane@univ-rennes1.fr(A.Amrane).tamination by dead-bacteria have to be solved to make such processes satisfactory for a safety use in drinking water treat-ment.Adsorption is a useful process for in situ treatment of underground and surface water,primarily due to it’s easy of use [3].Adsorbent resins are considered the most promising owing to their chemical stability and ability to control surface chemistry [4].The characteristics of adsorption behaviour are generally inferred in terms of both adsorption kinetics and equilibrium isotherms.They are also important tools to understand the adsorption mechanism,viz.the theoretical evaluation and inter-pretation of thermodynamic parameters[5,6].The objective of this study was to investigate equilibrium and kinetic parameters for the removal of nitrates from aqueous solutions by adsorption onto an ionized adsorbent,Amberlite IRA400.The Langmuir,Freundlich and Dubinin-Radushkevich (D-R)equations were used toﬁt the equilibrium isotherms.Ther-modynamic parameters were also evaluated through adsorption measurements.1385-8947/$–see front matter©2006Elsevier B.V.All rights reserved. doi:10.1016/j.cej.2006.08.014112M.Chabani et al./Chemical Engineering Journal125(2006)111–117Nomenclatureb Langmuir constant(cm3/mg)C0initial concentration in solution(mg/l)C e equilibrium concentration(mg/l)C t concentration at time t(mg/l)D p pore diffusion coefﬁcient(cm2/s)D fﬁlm diffusion coefﬁcient(cm2/s)E free energy of adsorption(kJ/mol)G Gibbs free energy(kJ/mol)H◦enthalpy of adsorption(kJ/mol)k overall rate constant of adsorption(min−1)k1forward rate constant(min−1)k2backward rate constant(min−1)k d distribution constant(l/g)k f Freundlich’s constant related to the sorptioncapacityk i intraparticle diffusion parameter(mg/g min0.5)m mass of adsorbent(g)n Freundlich’s constant related to the sorptionintensity of a sorbentq the amount of nitrates adsorbed or transferred(mg/l)q o maximum adsorption capacity(mg/g)q e adsorption capacity in equilibrium(mg/g)q t amount of adsorption at time t(mg/g)R ideal gas constant(8.314J/mol K)R p radius of the adsorbent(cm)S◦entropy of adsorption(J/mol K)t time(min)t1/2time for half adsorption(min)T temperature(K)v volume of solution(l)Greek letterεﬁlm thickness(cm)2.Materials2.1.Pre-treatment of resinBefore use,the resin was washed in distilled water to remove the adhering dirt and then dried at50◦C.After drying,the resin was screened to obtain a particle size range of0.3–0.8mm.2.2.The resin characteristicsThe main characteristics of the Amberlite IRA400(Merck, Darmstadt,Germany),a macroporous anion exchange resin,are given in Table1.2.3.Nitrate solutionsThe stock solution of NO3−used in this study was prepared by dissolving an accurate quantity of KNO3in distilled water.Table1Characteristics of Amberlite IRA400ion exchange resinPolymer matrix Polystyrene DVBFunctional group–N+R3Ionic form Cl−Exchange capacity 2.6–3eq kg−1of dry massAppearance Yellow to golden spherical beads,translucent Effective size0.3–0.8mmWater retention42–48%Visual density in wet state0.66–0.73g/mlTrue density in wet state 1.07–1.10g/mlA range of dilutions,1–18mg/l,was prepared from the stock solution.2.4.Sorption experimentsThe pH of the aqueous solutions of NO3−was approximately 6.8and did not varied signiﬁcantly with the dilution.The effect of temperature on the sorption rate of nitrates on Amberlite IRA400was investigated by equilibrating the sorption mix-ture(800ml)containing dried resin(2g)and nitrates(15mg/l) in a temperature range298–343K.The solutions were placed in ﬂasks and stirred for3h.Experiments were mainly carried out without initial adjustment of the pH.Preliminary tests showed that the adsorption was complete after1h.The concentration of residual nitrate ions was determined spectrophotometrically according to Rodier protocol[7].The sorption capacity at time t,q t(mg/g)was obtained as follows: q t=(C0−C t)vm(1) where C0and C t(mg/l)were the liquid-phase concentrations of solutes at the initial and a given time t,respectively,v(l)the volume of solution and m the mass resin(g).The amount of adsorption at equilibrium,q e was given by: q e=(C0−C e)vm(2) C e(mg/l)was the concentration of nitrates at equilibrium.The distribution constant k d was calculated using the follow-ing equation:k d=Amount of nitrates in adsorbentAmount of nitrates in solution×vm.(3) 3.Results and discussion3.1.Adsorption isothermsSorption equilibrium is usually described by an isotherm equation whose parameters express the surface properties and afﬁnity of the sorbent,at aﬁxed temperature and pH[8].An adsorption isotherm describes the relationship between the amount of adsorbate adsorbed on the adsorbent and the con-centration of dissolved adsorbate in the liquid at equilibrium. Equations often used to describe the experimental isotherm data are those developed by Freundlich[9],by Langmuir[10]and by Dubinin-Radushkevich[11].The Freundlich and LangmuirM.Chabani et al./Chemical Engineering Journal 125(2006)111–117113isotherms are the most commonly used to describe the adsorp-tion characteristics of adsorbent used in water and wastewater.3.1.1.Freundlich isotherm (1906)The empirical model can be applied to non-ideal sorption on heterogeneous surfaces as well as multilayer sorption and is expresses by the following equation:q e =k f C 1/ne(4)n and k f are the Freundlich constants.The ﬁt of data to Freundlich isotherm indicates the hetero-geneity of the sorbent surface.The magnitude of the exponent 1/n gives an indication of the adequacy and capacity of the adsor-bent/adsorbate system [12].In most cases,an exponent between 1and 10shows beneﬁcial adsorption.The linear plot of ln q e versus ln C e (Fig.1)shows that the adsorption obeys to the Fre-undlich model.k f and n were determined from the Freundlich plot and found to be 0.982and 1.074(Fig.1),respectively.n values above 1indicate favourable adsorption.ngmuir isotherm (1916)The Langmuir model is probably the best known and most widely applied sorption isotherm.It may be represented as fol-lows:q e =q o bC e1+bC e (5)The Langmuir constants q o and b are related to the adsorption capacity and the energy of adsorption,respectively.The linear plot of 1/q e versus 1/C e shows that the adsorption obeys to the Langmuir model (Fig.2),and gave the following values for q o and b ,769.2mg/g and 1.02cm 3/mg,respectively.3.1.3.Dubinin-Radushkevich (D-R)isothermRadushkevich [13]and Dubinin [14]have reported that the characteristic sorption curve is related to the porous structure of the sorbent.The sorption data were applied to the D-R model in order to distinguish between physical and chemical adsorption [15].The D-R equation was given by:ln q e =ln q o −βε2(6)Fig.1.Linearized Freundlich isotherm (Eq.(4))for nitrates adsorption by Amberlite IRA 400;T =25◦C,pH 6.8,adsorbent dose 1.25g/l.Fig.2.Linearized Langmuir isotherm (Eq.(5))for nitrates adsorption by Amber-lite IRA 400;T =25◦C,pH 6.8,adsorbent dose 1.25g/l.where βwas the activity coefﬁcient related to mean sorption energy and εthe Polanyi potential given by:ε=RT ln1+1e (7)where R was the gas constant (kJ/mol K)and T the temperature (K).The slope of the plot ln q e versus εgives β(mol 2/J 2)and the ordinate intercept yields the sorption capacity q o (mg/g).The mean sorption energy (E )is given by E =1/√−2β;for a magnitude of E between 8and 16kJ/mol,the adsorption process follows chemical ion-exchange [6,16],while values of E below 8kJ/mol characterize a physical adsorption process [17].The plot of ln q e against ε2for nitrate ions sorption on resin is shown in Fig.3.The E value was 40.8J/mol,which corresponds to a physical adsorption.The linear correlation coefﬁcients for Freundlich,Langmuir and D-R are shown in Table 2,and are always greater than 0.980.The Freundlich equation represents a better ﬁt of experimental data than Langmuir and D-Requations.Fig.3.Radushkevich-Dubinin isotherm (Eq.(6))for nitrates adsorption by Amberlite IRA 400;T =25◦C,pH 6.8,adsorbent dose 1.25g/l.114M.Chabani et al./Chemical Engineering Journal 125(2006)111–117Table 2Isotherm parameters collected for removal of nitrates by Amberlite IRA 400Freundlich constants k f 0.982n 1.074R 20.9951Langmuir constants q o (mg/g)769.2b (cm 3/mg) 1.02R 20.9933D-R constants q o (mg/g)76.5E (J/mol)40.8R 20.9873.2.Adsorption kinetics3.2.1.Effect of initial concentrationsPredicting the adsorption rate,in addition to the adsorbate residence time and the reactor dimensions,controlled by the system’s kinetics,are probably the most important factors in adsorption system design [18].Preliminary experiments showed high initial rates of adsorp-tion of nitrates followed by lower rates near equilibrium.Kinet-ics of nitrates removal at 298K showed high rates during the initial 15min,and decreased thereafter until nearly constant val-ues after 40min of adsorption (Fig.4).In batch adsorption processes the adsorbate molecules diffuse in porous adsorbent and the rate process usually depends upon t 1/2rather than the contact time,t [19,20]:q t =k i t 0.5(8)The plot of q t ,the amount of adsorbate adsorbed per unit weight of adsorbent versus square root of time has been com-monly used to describe an adsorption process controlled by diffusion in the adsorbent particle and consecutive diffusion in the bulk of the solution [21].Therefore,as can be observed in Fig.5,adsorption was linear and charaterized by extremelyfastFig.4.Time-courses of nitrates adsorption for different initial concentrations of nitricnitrogen.Fig.5.Effect of t 1/2on adsorption of nitrates by Amberlite IRA 400(Eq.(8)),adsorbent dose 1.25g/l,pH 6.8.uptake.During this phase,nitrates were adsorbed within a t 1/2value of about 10min;this behaviour can be attributed to the rapid use of the most readily available adsorbing sites on the adsorbent surface.After this phase,adsorption became negligi-ble.It may be attributed to a very slow diffusion of adsorbed nitrates from the ﬁlm surface into the micropores,which are the less accessible sites of adsorption [20,22,23].Fig.5shows two consecutive linear steps during the adsorption of nitrates on Amberlite IRA 400,and the deviation from the straight line indicates that the pore diffusion is not the only rate-limiting step.The slope of the linear portion from Fig.5was used to derive values for the rate parameter,k i ,for the intra-particle diffusion (Eq.(8)).The results show that intraparticle diffusion model was valid for the considered system.Kinetic parameters and correlation coefﬁcients obtained by the intra-particle model are given in Table 3.The values of k i increased for increasing initial concentrations.Kinetic data can further be used to check whether pore-diffusion was the only rate-controlling step or not in the adsorp-tion system using Bangham’s equation [24–26]:log log C 0C 0−qm =log k B m2.303v+a log t (9)As observed,the model did not match experimental data(Fig.6),showing that the diffusion in the pores of the sorbent wasTable 3Intraparticle diffusion (Eq.(8))kinetic parameters for adsorption of nitrates on Amberlite IRA 400resin at different concentrations Concentration of nitric nitrogen (mg/l)Intraparticle diffusion Correlation coefﬁcient R 2Kinetic parameters,k i (mg/g min 0.5)10.8740.5120.990 1.23.50.987 2.9150.990 3.93100.9038.75140.98211.7180.96615.5M.Chabani et al./Chemical Engineering Journal125(2006)111–117115Fig.6.Fit of adsorption kinetics at different initial concentrations of nitric nitro-gen by means of the Bangham’s model(Eq.(9)).not the only rate-controlling step.The correlation coefﬁcients given by the Bangham’s equation(Fig.6)conﬁrmed that the model did notﬁt satisfactory experimental data.Similar results were previously reported for4-CP adsorption by macroreticular resins[27]and for adsorption of4-chlorophenol by XAD-4[12].3.2.2.First-order reversible modelWhen a single species is considered to adsorb on a hetero-geneous surface,the adsorption of a solute from an aqueous solution follows reversible-ﬁrst-order kinetics[28,29].The het-erogeneous equilibrium between the solute in solution and the ion exchange resin may be expressed as:A k1k2B,(10)With k1the forward reaction rate and k2the backward reaction rate constant.If C0(mg/l)was the initial concentration of nitrates and q(mg/l)the amount transferred from the liquid phase to the solid phase at a given time t,then the rate was:d q d t =−d(C0−q)d t=k(C0−q)(11)where k(min−1)is the overall reaction rate constant.Since k1 (min−1)and k2(min−1)are the rate constants for the forward and the reverse processes,the rate can be expressed as:d qd t=k1(C0−q)−k2q(12)If X e(mg/l)represents the concentration of nitrates adsorbed at equilibrium,then at equilibrium:k1(C0−X e)−k2X e=0,d qd t=(k1+k2)(X e−q)(13) after integration,The above equation can be rearranged:ln(1−U t)=−(k1+k2)t=−kt(14) where U t=q/X e and k was the overall rate constant;U t,called the fractional attainment of equilibrium of nitrates,is givenby Fig.7.Fit of adsorption kinetics at different initial concentrations of nitric nitro-gen by means of the reversible-ﬁrst-order model(Eq.(14)).the following expression:U t=C0−C tC0−C e(15) where C0,C t and C e were the initial nitrates concentration,its concentration at a given time t and at equilibrium,respectively. The overall constant rate k for a given concentration corre-sponded to the slope of the straight line of the plot ln(1−U t) versus t(Fig.7).The equilibrium constant and the forward and backward constant rates k1and k2were calculated using Eq.(14)and are collected in Table4.The high correlation coefﬁcient values,if compared to that given in the available literature[30],conﬁrm the applicability of the model.It could be seen that the forward rate constants for the removal of nitrates were much higher than the backward rate constants for the des-orption process(Table4).The constant rates depend on the adsorption capacity,the diffusion coefﬁcient,the effective mass transfer area,the hydrodynamic of the system and other physico-chemical parameters.Ourﬁnding agreed with previous results [12].3.2.3.Diffusion processIn order to assess the nature of the diffusion process respon-sible for adsorption of nitrates on Amberlite IRA400,attempts were made to calculate the coefﬁcients of the process.Ifﬁlm dif-fusion was to be the rate-determining step in the adsorption of nitrates on the surface of the resin,the value of theﬁlm diffusion coefﬁcient(D f)should be in the range10−6to10−8cm2/s.If pore diffusion was to be rate limiting,the pore diffusion coefﬁ-cient(D p)should be in the range10−11to10−13cm2/s[31,32]. Assuming spherical geometry for the sorbent,the overall rate constant of the process can be correlated with the pore diffu-sion coefﬁcient and theﬁlm diffusion coefﬁcient independently according to[29]:Pore diffusion coefﬁcient:D p=0.03R2pt1/2,(16)andﬁlm diffusion coefﬁcient:D f=0.23R pε1/2q(17)116M.Chabani et al./Chemical Engineering Journal125(2006)111–117 Table4Constant rates for the removal of nitrates with Amberlite IRA400resin using reversible-ﬁrst-order model(Eq.(14))C0(mg/l)Correlationcoefﬁcients,R2Overall rate constant,k=k1+k2(min−1)Forward rate constant,k1(min−1)Backward rate constant,k2(min−1)10.9540.0860.0680.018 20.9940.0890.0770.012 3.50.9780.1160.1070.009 50.9850.1410.1290.011 100.9800.1370.1280.008 140.9750.1650.1510.013 180.9920.1630.1460.017 where R p was the radius of the adsorbent(R p=0.045cm),εtheﬁlm thickness(10−3cm)[19],q(mg/l)the amount of nitratesadsorbed and C0the initial concentration.By considering theappropriate data and the respective overall rate constants,poreandﬁlm diffusion coefﬁcients for various concentrations ofnitrates were determined(Table5).It clearly appeared thatnitrates removal on Amberlite IRA400resin was controlledbyﬁlm diffusion since coefﬁcient values were in the range10−6to10−8cm2/s.3.3.Thermodynamic studiesThe amounts of sorption of nitrates ions by Amberlite IRA400were measured in the range temperature298–343K.Ther-modynamic parameters were determined using the followingrelation[15,33–36]:ln k d= S◦R−H◦RT(18)where k d was the distribution coefﬁcient, H, S,and T the enthalpy,entropy and temperature(in Kelvin),respectively,and R was the gas constant.The values of enthalpy( H)and entropy ( S)were obtained from the slope and intercept of ln(k d)versus 1/T plot.Fig.8shows two linear parts in the temperature range explored.Aﬁrst decreasing part for a temperature range from 318to343K,and a second and increasing linear part for a tem-perature range from298to318K.Gibbs free energy( G)was calculated using the well-known equation:G= H−T S(19) The slope was positive in the temperature range298–318K and negative in a second step,from318to343K(Fig.8).The thermodynamic parameters are collected in Table6.Table5Diffusion coefﬁcients for the removal of nitrates by Amberlite IRA400resinC0(mg/l)Pore diffusion coefﬁcient,Eq.(16)(×10−7cm2/s)Film diffusion coefﬁcient, Eq.(17)(×10−8cm2/s)10.670.73 20.780.92 3.50.84 1.06 50.92 1.15 10 1.01 1.29 14 1.26 1.58 18 1.692.06Fig.8.Estimation of thermodynamic parameters(Eq.(18))for the adsorption of nitrates onto Amberlite IRA400.Table6Thermodynamic parameters for the adsorption of nitrates on Amberlite IRA400 298K308K318K318K333K343K G(kJ/mol)−5.631−4.944−4.256−2.66−3.692−4.38 H◦(kJ/mol)−26.122+19.205S◦(J/mol K)−68.76+68.76For theﬁrst range from298to318K,the negative value of enthalpy showed that the adsorption of nitrates was exother-mic.The negative values of adsorption entropy indicated that the adsorption process was reversible and demonstrated the sponta-neous nature of adsorption(Table6).In the range318–343K,Gibbs free energy( G)decreased for increasing temperatures,indicating that the reaction was spontaneous and favoured by higher temperatures.The positive value of enthalpy indicated that the adsorption was endothermic. The positive value of adsorption entropy showed the irreversibil-ity of the adsorption process and favoured complexation and stability of sorption.The resultant effect of complex bonding and steric hindrance of the sorbed species probably increased the enthalpy and the entropy of the system.4.ConclusionsThese results show that Amberlite IRA400is an effective adsorbent for the removal of nitrates from aqueous solution.TheM.Chabani et al./Chemical Engineering Journal125(2006)111–117117equilibrium between nitrates and resin was achieved in approx-imately60min,leading to96%removal of nitrates.The corre-lation coefﬁcient showed that Freundlich model gave a betterﬁt of experimental data than Langmuir and Dubinin-Radushkevich models.Adsorption kinetics was found to followﬁrst order reversible model expression.Theﬁlm diffusion was the main rate-limiting step.Temperature variations were used to evaluate enthalpy H, entropy S and Gibbs free energy G values.The negative value of G showed the spontaneous nature of adsorption.In the tem-perature range298–318K, H and S were negative,and the reaction was exothermic and reversible.From318to343K, H and S were positive,and the reaction was endothermic and irre-versible.In addition,positive S values favoured complexation and stability of sorption.References[1]N.¨Ozt¨u rk,T.Ennil Bektas,Nitrate removal from aqueous solution byadsorption onto various materials,J.Hazard.Mater.B112(2004)155–162.[2]H.Bouwer,Agricultural contamination:problems and solutions,WaterEnviron.Technol.(1989)292–297.[3]K.Mizuta,T.Matsumoto,Y.Hatate,K.Nishihara,T.Nakanishi,Removalof nitrate-nitrogen from drinking water using bamboo powder charcoal, Bioresour.Technol.95(2004)255–257.[4]N.I.Chubar,V.F.Samanidou,V.S.Kouts,G.G.Gallios,V.A.Kanibolotsky,V.V.Strelko,I.Z.Zhuravlev,Adsorption ofﬂuoride,chloride,bromide,and bromate ions on a novel ion exchanger,J.Colloid Interface Sci.291(2005) 67–74.[5]S.J.Allen,G.Mckay,J.F.Porter,Adsorption isotherm models for basicdye adsorption by peat in single and binary component systems,J.Colloid Interface Sci.280(2004)322–333.[6]A.¨Ozcan,A.S.¨Ozcan,S.Tunali,T.Akar,I.Kiran,Determination of theequilibrium,kinetic and thermodynamic parameters of adsorption of cop-per(II)ions onto seeds of Capsicum annuum,J.Hazard.Mater.B124(2005) 200–208.[7]J.Rodier,Water Analysis,seventh ed.,Dunod,Paris,1996(in French).[8]S.Sohn,D.Kim,Modelisation of Langmuir isotherm in solution systems-deﬁnition and utilization of concentration dependent factor,Chemosphere 58(2005)115–123.[9]H.M.F.Freundlich,¨Uber die adsorption in l¨o sungen,Zeitschrift f¨u rPhysikalische Chemie(Leipzig)57A(1906)385–470.[10]ngmuir,The constitution and fundamental properties of solids andliquids,J.Am.Chem.Soc.38(11)(1916)2221–2295.[11]M.M.Dubinin,E.D.Zaverina,L.V.Radushkevich,Sorbtsiyai strukturaaktivnykh uglei.I.Issledovanie adsorbtsii organicheskikh parov,Zhurnal Fizicheskoi Khimii21(11)(1947)1351–1363.[12]M.S.Bilgili,Adsorption of4-chlorophenol from aqueous solutions byXAD-4resin:isotherm,kinetic,and thermodynamic analysis,J.Hazard.Mater.137(2006)157–164.[13]L.V.Radushkevich,Potential theory of sorption and structure of carbons,Zhurnal Fizicheskoi Khimii23(1949)1410–1420.[14]M.M.Dubinin,Modern state of the theory of volumeﬁlling of microporeadsorbents during adsorption of gases and steams on carbon adsorbents, Zhurnal Fizicheskoi Khimii39(1965)1305–1317.[15]R.Donat,A.Akdogan,E.Erdem,H.Cetisli,Themodynamics of Pb2+andNi2+adsorption onto natural bentonite from aqueous solutions,J.Colloid Interface Sci.286(2005)43–52.[16]F.Helffrich,Ion Exchange,McGraw Hill,New York,1962.[17]M.S.Onyango,Y.Kojima,O.Aoyi,E.C.Bernardo,H.Matsuda,Adsorp-tion equilibrium modelling and solution chemistry dependence ofﬂuoride removal from water by trivalent-cation exchange zeolite F-9,J.Colloid Interface Sci.279(2004)341–350.[18]Y.S.Ho,Review of second-order models for adsorption systems,J.Hazard.Mater.136(2006)681–689.[19]W.J.Weber,J.C.Morris,Adsorption Processes for Water Treatment,But-terworth,London,1987.[20]Q.Feng,Q.Lin,F.Gong,S.Sugita,M.Shoya,Adsorption of lead andmercury by rice husk ash,J.Colloid Interface Sci.278(2004)1–8. 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SCI论文摘要中常用的表达方法

SCI论文摘要中常用的表达方法要写好摘要，需要建立一个适合自己需要的句型库（选择的词汇来源于SCI高被引用论文）引言部分（1）回顾研究背景，常用词汇有review, summarize, present, outline, describe等（2）说明写作目的，常用词汇有purpose, attempt, aim等，另外还可以用动词不定式充当目的壮语老表达（3）介绍论文的重点内容或研究范围，常用词汇有study, present, include, focus, emphasize, emphasis, attention等方法部分（1）介绍研究或试验过程，常用词汇有test study, investigate, examine,experiment, discuss, consider, analyze, analysis等（2）说明研究或试验方法，常用词汇有measure, estimate, calculate等（3）介绍应用、用途，常用词汇有use, apply, application等结果部分（1）展示研究结果，常用词汇有show, result, present等（2）介绍结论，常用词汇有summary, introduce,conclude等讨论部分（1）陈述论文的论点和作者的观点，常用词汇有suggest, repot, present, expect, describe 等（2）说明论证，常用词汇有support, provide, indicate, identify, find, demonstrate, confirm, clarify等（3）推荐和建议，常用词汇有suggest,suggestion, recommend, recommendation, propose,necessity,necessary,expect等。

摘要引言部分案例词汇review•Author(s): ROBINSON, TE; BERRIDGE, KC•Title:THE NEURAL BASIS OF DRUG CRA VING - AN INCENTIVE-SENSITIZATION THEORY OF ADDICTION•Source: BRAIN RESEARCH REVIEWS, 18 (3): 247-291 SEP-DEC 1993 《脑研究评论》荷兰SCI被引用1774We review evidence for this view of addiction and discuss its implications for understanding the psychology and neurobiology of addiction.回顾研究背景SCI高被引摘要引言部分案例词汇summarizeAuthor(s): Barnett, RM; Carone, CD; 被引用1571Title: Particles and field .1. Review of particle physicsSource: PHYSICAL REVIEW D, 54 (1): 1-+ Part 1 JUL 1 1996:《物理学评论，D辑》美国引言部分回顾研究背景常用词汇summarizeAbstract: This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 1900 new measurements from 700 papers, we list, evaluate, and average measuredproperties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review.SCI摘要引言部分案例attentionSCI摘要方法部分案例considerSCI高被引摘要引言部分案例词汇outline•Author(s): TIERNEY, L SCI引用728次•Title:MARKOV-CHAINS FOR EXPLORING POSTERIOR DISTRIBUTIONS 引言部分回顾研究背景，常用词汇outline•Source: ANNALS OF STATISTICS, 22 (4): 1701-1728 DEC 1994•《统计学纪事》美国•Abstract: Several Markov chain methods are available for sampling from a posterior distribution. Two important examples are the Gibbs sampler and the Metropolis algorithm.In addition, several strategies are available for constructing hybrid algorithms. This paper outlines some of the basic methods and strategies and discusses some related theoretical and practical issues. On the theoretical side, results from the theory of general state space Markov chains can be used to obtain convergence rates, laws of large numbers and central limit theorems for estimates obtained from Markov chain methods. These theoretical results can be used to guide the construction of more efficient algorithms. For the practical use of Markov chain methods, standard simulation methodology provides several Variance reduction techniques and also gives guidance on the choice of sample size and allocation.SCI高被引摘要引言部分案例回顾研究背景presentAuthor(s): L YNCH, M; MILLIGAN, BG SC I被引用661Title: ANAL YSIS OF POPULATION GENETIC-STRUCTURE WITH RAPD MARKERS Source: MOLECULAR ECOLOGY, 3 (2): 91-99 APR 1994《分子生态学》英国Abstract: Recent advances in the application of the polymerase chain reaction make it possible to score individuals at a large number of loci. The RAPD (random amplified polymorphic DNA) method is one such technique that has attracted widespread interest.The analysis of population structure with RAPD data is hampered by the lack of complete genotypic information resulting from dominance, since this enhances the sampling variance associated with single loci as well as induces bias in parameter estimation. We present estimators for several population-genetic parameters (gene and genotype frequencies, within- and between-population heterozygosities, degree of inbreeding and population subdivision, and degree of individual relatedness) along with expressions for their sampling variances. Although completely unbiased estimators do not appear to be possible with RAPDs, several steps are suggested that will insure that the bias in parameter estimates is negligible. To achieve the same degree of statistical power, on the order of 2 to 10 times more individuals need to be sampled per locus when dominant markers are relied upon, as compared to codominant (RFLP, isozyme) markers. Moreover, to avoid bias in parameter estimation, the marker alleles for most of these loci should be in relatively low frequency. Due to the need for pruning loci with low-frequency null alleles, more loci also need to be sampled with RAPDs than with more conventional markers, and sole problems of bias cannot be completely eliminated.SCI高被引摘要引言部分案例词汇describe•Author(s): CLONINGER, CR; SVRAKIC, DM; PRZYBECK, TR•Title: A PSYCHOBIOLOGICAL MODEL OF TEMPERAMENT AND CHARACTER•Source: ARCHIVES OF GENERAL PSYCHIATRY, 50 (12): 975-990 DEC 1993《普通精神病学纪要》美国•引言部分回顾研究背景，常用词汇describe 被引用926•Abstract: In this study, we describe a psychobiological model of the structure and development of personality that accounts for dimensions of both temperament and character. Previous research has confirmed four dimensions of temperament: novelty seeking, harm avoidance, reward dependence, and persistence, which are independently heritable, manifest early in life, and involve preconceptual biases in perceptual memory and habit formation. For the first time, we describe three dimensions of character that mature in adulthood and influence personal and social effectiveness by insight learning about self-concepts.Self-concepts vary according to the extent to which a person identifies the self as (1) an autonomous individual, (2) an integral part of humanity, and (3) an integral part of the universe as a whole. Each aspect of self-concept corresponds to one of three character dimensions called self-directedness, cooperativeness, and self-transcendence, respectively. We also describe the conceptual background and development of a self-report measure of these dimensions, the Temperament and Character Inventory. Data on 300 individuals from the general population support the reliability and structure of these seven personality dimensions. We discuss the implications for studies of information processing, inheritance, development, diagnosis, and treatment.摘要引言部分案例•（2）说明写作目的，常用词汇有purpose, attempt, aimSCI高被引摘要引言部分案例attempt说明写作目的•Author(s): Donoho, DL; Johnstone, IM•Title: Adapting to unknown smoothness via wavelet shrinkage•Source: JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION, 90 (432): 1200-1224 DEC 1995 《美国统计学会志》被引用429次•Abstract: We attempt to recover a function of unknown smoothness from noisy sampled data. We introduce a procedure, SureShrink, that suppresses noise by thresholding the empirical wavelet coefficients. The thresholding is adaptive: A threshold level is assigned to each dyadic resolution level by the principle of minimizing the Stein unbiased estimate of risk (Sure) for threshold estimates. The computational effort of the overall procedure is order N.log(N) as a function of the sample size N. SureShrink is smoothness adaptive: If the unknown function contains jumps, then the reconstruction (essentially) does also; if the unknown function has a smooth piece, then the reconstruction is (essentially) as smooth as the mother wavelet will allow. The procedure is in a sense optimally smoothness adaptive: It is near minimax simultaneously over a whole interval of the Besov scale; the size of this interval depends on the choice of mother wavelet. We know from a previous paper by the authors that traditional smoothing methods-kernels, splines, and orthogonal series estimates-even with optimal choices of the smoothing parameter, would be unable to perform in a near-minimax way over many spaces in the Besov scale.Examples of SureShrink are given. The advantages of the method are particularly evident when the underlying function has jump discontinuities on a smooth backgroundSCI高被引摘要引言部分案例To investigate说明写作目的•Author(s): OLTV AI, ZN; MILLIMAN, CL; KORSMEYER, SJ•Title: BCL-2 HETERODIMERIZES IN-VIVO WITH A CONSERVED HOMOLOG, BAX, THAT ACCELERATES PROGRAMMED CELL-DEATH•Source: CELL, 74 (4): 609-619 AUG 27 1993 被引用3233•Abstract: Bcl-2 protein is able to repress a number of apoptotic death programs. To investigate the mechanism of Bcl-2's effect, we examined whether Bcl-2 interacted with other proteins. We identified an associated 21 kd protein partner, Bax, that has extensive amino acid homology with Bcl-2, focused within highly conserved domains I and II. Bax is encoded by six exons and demonstrates a complex pattern of alternative RNA splicing that predicts a 21 kd membrane (alpha) and two forms of cytosolic protein (beta and gamma). Bax homodimerizes and forms heterodimers with Bcl-2 in vivo. Overexpressed Bax accelerates apoptotic death induced by cytokine deprivation in an IL-3-dependent cell line. Overexpressed Bax also counters the death repressor activity of Bcl-2. These data suggest a model in which the ratio of Bcl-2 to Bax determines survival or death following an apoptotic stimulus.SCI高被引摘要引言部分案例purposes说明写作目的•Author(s): ROGERS, FJ; IGLESIAS, CA•Title: RADIATIVE ATOMIC ROSSELAND MEAN OPACITY TABLES•Source: ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 79 (2): 507-568 APR 1992 《天体物理学杂志增刊》美国SCI被引用512•Abstract: For more than two decades the astrophysics community has depended on opacity tables produced at Los Alamos. In the present work we offer new radiative Rosseland mean opacity tables calculated with the OPAL code developed independently at LLNL. We give extensive results for the recent Anders-Grevesse mixture which allow accurate interpolation in temperature, density, hydrogen mass fraction, as well as metal mass fraction. The tables are organized differently from previous work. Instead of rows and columns of constant temperature and density, we use temperature and follow tracks of constant R, where R = density/(temperature)3. The range of R and temperature are such as to cover typical stellar conditions from the interior through the envelope and the hotter atmospheres. Cool atmospheres are not considered since photoabsorption by molecules is neglected. Only radiative processes are taken into account so that electron conduction is not included. For comparison purposes we present some opacity tables for the Ross-Aller and Cox-Tabor metal abundances. Although in many regions the OPAL opacities are similar to previous work, large differences are reported.For example, factors of 2-3 opacity enhancements are found in stellar envelop conditions.SCI高被引摘要引言部分案例aim说明写作目的•Author(s):EDV ARDSSON, B; ANDERSEN, J; GUSTAFSSON, B; LAMBERT, DL;NISSEN, PE; TOMKIN, J•Title:THE CHEMICAL EVOLUTION OF THE GALACTIC DISK .1. ANALYSISAND RESULTS•Source: ASTRONOMY AND ASTROPHYSICS, 275 (1): 101-152 AUG 1993 《天文学与天体物理学》被引用934•Abstract:With the aim to provide observational constraints on the evolution of the galactic disk, we have derived abundances of 0, Na, Mg, Al, Si, Ca, Ti, Fe, Ni, Y, Zr, Ba and Nd, as well as individual photometric ages, for 189 nearby field F and G disk dwarfs.The galactic orbital properties of all stars have been derived from accurate kinematic data, enabling estimates to be made of the distances from the galactic center of the stars‘ birthplaces. 结构式摘要•Our extensive high resolution, high S/N, spectroscopic observations of carefully selected northern and southern stars provide accurate equivalent widths of up to 86 unblended absorption lines per star between 5000 and 9000 angstrom. The abundance analysis was made with greatly improved theoretical LTE model atmospheres. Through the inclusion of a great number of iron-peak element absorption lines the model fluxes reproduce the observed UV and visual fluxes with good accuracy. A new theoretical calibration of T(eff) as a function of Stromgren b - y for solar-type dwarfs has been established. The new models and T(eff) scale are shown to yield good agreement between photometric and spectroscopic measurements of effective temperatures and surface gravities, but the photometrically derived very high overall metallicities for the most metal rich stars are not supported by the spectroscopic analysis of weak spectral lines.•Author(s): PAYNE, MC; TETER, MP; ALLAN, DC; ARIAS, TA; JOANNOPOULOS, JD•Title:ITERA TIVE MINIMIZATION TECHNIQUES FOR ABINITIO TOTAL-ENERGY CALCULATIONS - MOLECULAR-DYNAMICS AND CONJUGA TE GRADIENTS•Source: REVIEWS OF MODERN PHYSICS, 64 (4): 1045-1097 OCT 1992 《现代物理学评论》美国American Physical Society SCI被引用2654 •Abstract: This article describes recent technical developments that have made the total-energy pseudopotential the most powerful ab initio quantum-mechanical modeling method presently available. In addition to presenting technical details of the pseudopotential method, the article aims to heighten awareness of the capabilities of the method in order to stimulate its application to as wide a range of problems in as many scientific disciplines as possible.SCI高被引摘要引言部分案例includes介绍论文的重点内容或研究范围•Author(s):MARCHESINI, G; WEBBER, BR; ABBIENDI, G; KNOWLES, IG;SEYMOUR, MH; STANCO, L•Title: HERWIG 5.1 - A MONTE-CARLO EVENT GENERA TOR FOR SIMULATING HADRON EMISSION REACTIONS WITH INTERFERING GLUONS SCI被引用955次•Source: COMPUTER PHYSICS COMMUNICATIONS, 67 (3): 465-508 JAN 1992:《计算机物理学通讯》荷兰Elsevier•Abstract: HERWIG is a general-purpose particle-physics event generator, which includes the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron scattering and soft hadron-hadron collisions in one package. It uses the parton-shower approach for initial-state and final-state QCD radiation, including colour coherence effects and azimuthal correlations both within and between jets. This article includes a brief review of the physics underlying HERWIG, followed by a description of the program itself. This includes details of the input and control parameters used by the program, and the output data provided by it. Sample output from a typical simulation is given and annotated.SCI高被引摘要引言部分案例presents介绍论文的重点内容或研究范围•Author(s): IDSO, KE; IDSO, SB•Title: PLANT-RESPONSES TO ATMOSPHERIC CO2 ENRICHMENT IN THE FACE OF ENVIRONMENTAL CONSTRAINTS - A REVIEW OF THE PAST 10 YEARS RESEARCH•Source: AGRICULTURAL AND FOREST METEOROLOGY, 69 (3-4): 153-203 JUL 1994 《农业和林业气象学》荷兰Elsevier 被引用225•Abstract:This paper presents a detailed analysis of several hundred plant carbon exchange rate (CER) and dry weight (DW) responses to atmospheric CO2 enrichment determined over the past 10 years. It demonstrates that the percentage increase in plant growth produced by raising the air's CO2 content is generally not reduced by less than optimal levels of light, water or soil nutrients, nor by high temperatures, salinity or gaseous air pollution. More often than not, in fact, the data show the relative growth-enhancing effects of atmospheric CO2 enrichment to be greatest when resource limitations and environmental stresses are most severe.SCI高被引摘要引言部分案例介绍论文的重点内容或研究范围emphasizing •Author(s): BESAG, J; GREEN, P; HIGDON, D; MENGERSEN, K•Title: BAYESIAN COMPUTATION AND STOCHASTIC-SYSTEMS•Source: STATISTICAL SCIENCE, 10 (1): 3-41 FEB 1995《统计科学》美国•SCI被引用296次•Abstract: Markov chain Monte Carlo (MCMC) methods have been used extensively in statistical physics over the last 40 years, in spatial statistics for the past 20 and in Bayesian image analysis over the last decade. In the last five years, MCMC has been introduced into significance testing, general Bayesian inference and maximum likelihood estimation. This paper presents basic methodology of MCMC, emphasizing the Bayesian paradigm, conditional probability and the intimate relationship with Markov random fields in spatial statistics.Hastings algorithms are discussed, including Gibbs, Metropolis and some other variations. Pairwise difference priors are described and are used subsequently in three Bayesian applications, in each of which there is a pronounced spatial or temporal aspect to the modeling. The examples involve logistic regression in the presence of unobserved covariates and ordinal factors; the analysis of agricultural field experiments, with adjustment for fertility gradients; and processing oflow-resolution medical images obtained by a gamma camera. Additional methodological issues arise in each of these applications and in the Appendices. The paper lays particular emphasis on the calculation of posterior probabilities and concurs with others in its view that MCMC facilitates a fundamental breakthrough in applied Bayesian modeling.SCI高被引摘要引言部分案例介绍论文的重点内容或研究范围focuses •Author(s): HUNT, KJ; SBARBARO, D; ZBIKOWSKI, R; GAWTHROP, PJ•Title: NEURAL NETWORKS FOR CONTROL-SYSTEMS - A SURVEY•Source: AUTOMA TICA, 28 (6): 1083-1112 NOV 1992《自动学》荷兰Elsevier•SCI被引用427次•Abstract:This paper focuses on the promise of artificial neural networks in the realm of modelling, identification and control of nonlinear systems. The basic ideas and techniques of artificial neural networks are presented in language and notation familiar to control engineers. Applications of a variety of neural network architectures in control are surveyed. We explore the links between the fields of control science and neural networks in a unified presentation and identify key areas for future research.SCI高被引摘要引言部分案例介绍论文的重点内容或研究范围focus•Author(s): Stuiver, M; Reimer, PJ; Bard, E; Beck, JW;•Title: INTCAL98 radiocarbon age calibration, 24,000-0 cal BP•Source: RADIOCARBON, 40 (3): 1041-1083 1998《放射性碳》美国SCI被引用2131次•Abstract: The focus of this paper is the conversion of radiocarbon ages to calibrated (cal) ages for the interval 24,000-0 cal BP (Before Present, 0 cal BP = AD 1950), based upon a sample set of dendrochronologically dated tree rings, uranium-thorium dated corals, and varve-counted marine sediment. The C-14 age-cal age information, produced by many laboratories, is converted to Delta(14)C profiles and calibration curves, for the atmosphere as well as the oceans. We discuss offsets in measured C-14 ages and the errors therein, regional C-14 age differences, tree-coral C-14 age comparisons and the time dependence of marine reservoir ages, and evaluate decadal vs. single-year C-14 results. Changes in oceanic deepwater circulation, especially for the 16,000-11,000 cal sp interval, are reflected in the Delta(14)C values of INTCAL98.SCI高被引摘要引言部分案例介绍论文的重点内容或研究范围emphasis •Author(s): LEBRETON, JD; BURNHAM, KP; CLOBERT, J; ANDERSON, DR•Title: MODELING SURVIV AL AND TESTING BIOLOGICAL HYPOTHESES USING MARKED ANIMALS - A UNIFIED APPROACH WITH CASE-STUDIES •Source: ECOLOGICAL MONOGRAPHS, 62 (1): 67-118 MAR 1992•《生态学论丛》美国•Abstract: The understanding of the dynamics of animal populations and of related ecological and evolutionary issues frequently depends on a direct analysis of life history parameters. For instance, examination of trade-offs between reproduction and survival usually rely on individually marked animals, for which the exact time of death is most often unknown, because marked individuals cannot be followed closely through time.Thus, the quantitative analysis of survival studies and experiments must be based oncapture-recapture (or resighting) models which consider, besides the parameters of primary interest, recapture or resighting rates that are nuisance parameters. 结构式摘要•T his paper synthesizes, using a common framework, these recent developments together with new ones, with an emphasis on flexibility in modeling, model selection, and the analysis of multiple data sets. The effects on survival and capture rates of time, age, and categorical variables characterizing the individuals (e.g., sex) can be considered, as well as interactions between such effects. This "analysis of variance" philosophy emphasizes the structure of the survival and capture process rather than the technical characteristics of any particular model. The flexible array of models encompassed in this synthesis uses a common notation. As a result of the great level of flexibility and relevance achieved, the focus is changed from fitting a particular model to model building and model selection.SCI摘要方法部分案例•方法部分•（1）介绍研究或试验过程，常用词汇有test，study, investigate, examine,experiment, discuss, consider, analyze, analysis等•（2）说明研究或试验方法，常用词汇有measure, estimate, calculate等•（3）介绍应用、用途，常用词汇有use, apply, application等SCI高被引摘要方法部分案例discusses介绍研究或试验过程•Author(s): LIANG, KY; ZEGER, SL; QAQISH, B•Title: MULTIV ARIATE REGRESSION-ANAL YSES FOR CATEGORICAL-DATA •Source:JOURNAL OF THE ROY AL STA TISTICAL SOCIETY SERIES B-METHODOLOGICAL, 54 (1): 3-40 1992《皇家统计学会志，B辑：统计方法论》•SCI被引用298•Abstract: It is common to observe a vector of discrete and/or continuous responses in scientific problems where the objective is to characterize the dependence of each response on explanatory variables and to account for the association between the outcomes. The response vector can comprise repeated observations on one variable, as in longitudinal studies or genetic studies of families, or can include observations for different variables.This paper discusses a class of models for the marginal expectations of each response and for pairwise associations. The marginal models are contrasted with log-linear models.Two generalized estimating equation approaches are compared for parameter estimation.The first focuses on the regression parameters; the second simultaneously estimates the regression and association parameters. The robustness and efficiency of each is discussed.The methods are illustrated with analyses of two data sets from public health research SCI高被引摘要方法部分案例介绍研究或试验过程examines•Author(s): Huo, QS; Margolese, DI; Stucky, GD•Title: Surfactant control of phases in the synthesis of mesoporous silica-based materials •Source: CHEMISTRY OF MATERIALS, 8 (5): 1147-1160 MAY 1996•SCI被引用643次《材料的化学性质》美国•Abstract: The low-temperature formation of liquid-crystal-like arrays made up of molecular complexes formed between molecular inorganic species and amphiphilic organic molecules is a convenient approach for the synthesis of mesostructure materials.This paper examines how the molecular shapes of covalent organosilanes, quaternary ammonium surfactants, and mixed surfactants in various reaction conditions can be used to synthesize silica-based mesophase configurations, MCM-41 (2d hexagonal, p6m), MCM-48 (cubic Ia3d), MCM-50 (lamellar), SBA-1 (cubic Pm3n), SBA-2 (3d hexagonal P6(3)/mmc), and SBA-3(hexagonal p6m from acidic synthesis media). The structural function of surfactants in mesophase formation can to a first approximation be related to that of classical surfactants in water or other solvents with parallel roles for organic additives. The effective surfactant ion pair packing parameter, g = V/alpha(0)l, remains a useful molecular structure-directing index to characterize the geometry of the mesophase products, and phase transitions may be viewed as a variation of g in the liquid-crystal-Like solid phase. Solvent and cosolvent structure direction can be effectively used by varying polarity, hydrophobic/hydrophilic properties and functionalizing the surfactant molecule, for example with hydroxy group or variable charge. Surfactants and synthesis conditions can be chosen and controlled to obtain predicted silica-based mesophase products. A room-temperature synthesis of the bicontinuous cubic phase, MCM-48, is presented. A low-temperature (100 degrees C) and low-pH (7-10) treatment approach that can be used to give MCM-41 with high-quality, large pores (up to 60 Angstrom), and pore volumes as large as 1.6 cm(3)/g is described.Estimates 介绍研究或试验过程SCI高被引摘要方法部分案例•Author(s): KESSLER, RC; MCGONAGLE, KA; ZHAO, SY; NELSON, CB; HUGHES, M; ESHLEMAN, S; WITTCHEN, HU; KENDLER, KS•Title:LIFETIME AND 12-MONTH PREV ALENCE OF DSM-III-R PSYCHIATRIC-DISORDERS IN THE UNITED-STA TES - RESULTS FROM THE NATIONAL-COMORBIDITY-SURVEY•Source: ARCHIVES OF GENERAL PSYCHIATRY, 51 (1): 8-19 JAN 1994•《普通精神病学纪要》美国SCI被引用4350次•Abstract: Background: This study presents estimates of lifetime and 12-month prevalence of 14 DSM-III-R psychiatric disorders from the National Comorbidity Survey, the first survey to administer a structured psychiatric interview to a national probability sample in the United States.Methods: The DSM-III-R psychiatric disorders among persons aged 15 to 54 years in the noninstitutionalized civilian population of the United States were assessed with data collected by lay interviewers using a revised version of the Composite International Diagnostic Interview. Results: Nearly 50% of respondents reported at least one lifetime disorder, and close to 30% reported at least one 12-month disorder. The most common disorders were major depressive episode, alcohol dependence, social phobia, and simple phobia. More than half of all lifetime disorders occurred in the 14% of the population who had a history of three or more comorbid disorders. These highly comorbid people also included the vast majority of people with severe disorders.Less than 40% of those with a lifetime disorder had ever received professional treatment,and less than 20% of those with a recent disorder had been in treatment during the past 12 months. Consistent with previous risk factor research, it was found that women had elevated rates of affective disorders and anxiety disorders, that men had elevated rates of substance use disorders and antisocial personality disorder, and that most disorders declined with age and with higher socioeconomic status. Conclusions: The prevalence of psychiatric disorders is greater than previously thought to be the case. Furthermore, this morbidity is more highly concentrated than previously recognized in roughly one sixth of the population who have a history of three or more comorbid disorders. This suggests that the causes and consequences of high comorbidity should be the focus of research attention. The majority of people with psychiatric disorders fail to obtain professional treatment. Even among people with a lifetime history of three or more comorbid disorders, the proportion who ever obtain specialty sector mental health treatment is less than 50%.These results argue for the importance of more outreach and more research on barriers to professional help-seekingSCI高被引摘要方法部分案例说明研究或试验方法measure•Author(s): Schlegel, DJ; Finkbeiner, DP; Davis, M•Title:Maps of dust infrared emission for use in estimation of reddening and cosmic microwave background radiation foregrounds•Source: ASTROPHYSICAL JOURNAL, 500 (2): 525-553 Part 1 JUN 20 1998 SCI 被引用2972 次《天体物理学杂志》美国•The primary use of these maps is likely to be as a new estimator of Galactic extinction. To calibrate our maps, we assume a standard reddening law and use the colors of elliptical galaxies to measure the reddening per unit flux density of 100 mu m emission. We find consistent calibration using the B-R color distribution of a sample of the 106 brightest cluster ellipticals, as well as a sample of 384 ellipticals with B-V and Mg line strength measurements. For the latter sample, we use the correlation of intrinsic B-V versus Mg, index to tighten the power of the test greatly. We demonstrate that the new maps are twice as accurate as the older Burstein-Heiles reddening estimates in regions of low and moderate reddening. The maps are expected to be significantly more accurate in regions of high reddening. These dust maps will also be useful for estimating millimeter emission that contaminates cosmic microwave background radiation experiments and for estimating soft X-ray absorption. We describe how to access our maps readily for general use.SCI高被引摘要结果部分案例application介绍应用、用途•Author(s): MALLAT, S; ZHONG, S•Title: CHARACTERIZATION OF SIGNALS FROM MULTISCALE EDGES•Source: IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, 14 (7): 710-732 JUL 1992•SCI被引用508次《IEEE模式分析与机器智能汇刊》美国•Abstract: A multiscale Canny edge detection is equivalent to finding the local maxima ofa wavelet transform. We study the properties of multiscale edges through the wavelet。

贵州省六盘水二十中学2024年中考二模英语试题含答案

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Ⅰ. 单项选择1、_______ good advice she provided! It did help me a lot!A．How a B．What aC．How D．What2、Nowadays, more and more people have taken an interest ________ watching The Voice of China ________ Friday evening.A．in; in B．at; on C．in; on3、They will lose the game _______ they try their best.A．unless B．once C．since D．after4、I have some trouble with my English writing. Can you give me some ______ ?A．advice B．decisions C．messages D．suggestion5、Today’s young people can’t live without smart phones. They keep their hands on the phones whenever they go, even while they______ meals.A．had B．will have C．were having D．are having6、When you visit a foreign country,it is important to know how to ask for help ______.A．wisely B．lately C．widely D．politely7、- How was your May Day holiday?- Just so so.We drove to Hangzhou and tried to find a place for parking, but they were all _____.A．taken up B．given up C．stayed up D．picked up8、Millie Beijing now.A．don't live in B．doesn't lives inC．don't lives in D．doesn't live in9、—I feel tired and sleepy.—Why not ________ for a while?A．stop to rest B．stopping to restC．stop resting D．stopping resting10、Y ou'd better______ more time talking with your parents so that they can understand you better.A．spend B．take C．cost D．payⅡ. 完形填空11、There was once a greedy(贪婪的) dog. It got a piece of 1 in his mouth. He was going to 2 itat home by himself. When he was 3 on a bridge, he looked down and saw a dog in the 4 . That dog looked at him and he had a piece of meat in his mouth, too. The dog 5 there was another dog in the river. So he said to himself, “I want to eat his meat. I must make him run 6 from here and get the meat in his mouth, then I can have 7 pieces of meat.” He opened his mouth and 8 at the dog in the river. But the meat in his mouth went down into the river. The dog was so 9 , so he jumped into the river and wanted to 10 the other dog. Of course, the greedy dog got nothing in the end.1．A．cake B．bread C．meat D．food2．A．cook B．put C．eat D．cut3．A．walking B．running C．dancing D．looking4．A．tree B．river C．pool D．lake5．A．looked B．told C．watched D．thought6．A．away B．out C．down D．up7．A．one B．two C．three D．no8．A．cried B．barked C．shouted D．looked9．A．nervous B．happy C．surprised D．angry10．A．run B．see C．find D．catchⅢ. 语法填空12、Not everyone has the chance 1．( be ) a detective(侦探). But I got one when I was 13 years old. It happened in 1988. One afternoon, I 2．( walk ) down the street when I saw my father's new car. I expected 3．(meet) my father, but to my surprise, I saw a young woman driving instead. "My father's car 4．(steal)" I thought. So I quickly stopped a taxi and got in. I said to the driver, "Please 5．(follow) that new car in front." And I told him why.The taxi driver had a car phone, and I asked him to call the police. Soon we heard the sound of a police car and its loudspeaker. The police told the woman to stop her car. Our car came to a stop, too. I got out right now and 6．(say) to the woman, "It's not your car. It's my father's."The woman smiled and said, "Oh. Y ou're Mr. Johnson's younger son, right? I 7．see) your photo at your father's office." Before I could say another word, the woman explained that she was my father's new assistant.My father asked her to take his computer to the shop to have it repaired. He lent his car. After 8．(hear) her words, we called my father and he told us what she said was true. The police and the taxi driver laughed I felt very sorry. It was both the first and last time for me to work as a detective. Don't you think my story funny?Ⅳ. 阅读理解A13、People, especially English people, love talking about the weather. It’s an easy way to start a conversation.But do you know some weather terms can also express a feeling or situation. Here are some interesting expressions.Head in the cloudsIf someone has his head in the clouds, they are out of touch with the everyday world and can be unrealistic as a result.The expression reminds you to be aware of what’s happening around you.Take a rain checkIf you hear someone say “I’ll take a rain check”, it doesn’t mean that he will go out to see if it’s raining.In fact, the expression could be used as a polite way to turn down invitations. However, not as a full refusal, but more likely to put the invitation off to another time.When it rains, it poursThe expression is used when something goes wrong, especially when a lot of things go wrong at the same time. People like to say it when they meet with bad lucks one after another in a short time.Weather the stormAs an extreme weather, a storm could be very dangerous and cause serious results. To weather the storm is to get through difficult situations in your life.1．Why do English people love talking about the weather in the writer’s opinion?A．They care about the weather very much.B．They want to know what’s happening around them.C．They don’t have other interesting things to talk about.D．They think it’s an easy w ay to start a conversation.2．What does the underlined phrase “turn down” mean?A．accept B．refuse C．throw D．change3．Which of the following statements is true?A．The whole article is telling us how to tell the weather.B．The writer thinks if someone has hi s head in the clouds, the person must care about what’s happening very much. C．When somebody says “when it rains, it pours”, he must be unlucky.D．The expression “weather the storm” can be used to put off an appointment.B14、In 1921, long before the Walt Disney Company turned Pooh （维尼熊）into an international star of TV and films, Christopher Robin Milne was given a toy bear on his first birthday from his father, A．A．Milne, who bought the stuffed animal from a store. The stuffed animal was named Edward Bear. Y ears later, Edward was named Winnie.From the time Christopher Robin Milne was a baby until he was about 8 years old, he would receive different stuffed animals.A．A．Milne was a famous English author. As he watched his son interact （互动）with Winnie and friends, A．A．Milne thought his child's interaction with the collection of animals would make a great bedtime story. So Milne worked with artist Ernest H. Shepard and wrote the first Winnie the Pooh poem, where Edward Bear was known as “Teddy Bear” The writings appeared in Punch magazine and in the book they wrote together, When We Were V ery Young, which was published in 1924. In a four-year period, three more books that centered on the bear and his team followed: 1926's Winnie-the-Pooh, 1927' Now We Are Six, and 1928's The House at Pooh Corner.The books and poems about Pooh brought great success to the author, and the characters became favorites with young children and their families around the world. Their popularity led Disney to get the rights to make films about the characters in 1961. Five years later, Pooh, Tigger, Piglet and the rest of the team appeared on screen for the first time in Winnie-the-Pooh and the Honey Tree. The characters later appeared in TV shows, movies, video games and short films. Pooh's most recent appearance came last year in the popular children's program, DocMcStufftns, where he was a special guest.1．What do we know about Edward Bear according to the passage?A．It was just a birthday gift for a baby. B．It was a popular toy bear among kids.C．It was an international star of many films. D．It was given to Christopher when he was 8.2．What did a Milne do according to Paragraph 2?A．He wrote many books about Pooh.B．He read many bedtime stories to his son.C．He wrote 5 books with Ernest H. Shepard.D．He encouraged his son to play with friends3．In what order did the following events take place?A．c-a-d-e-b B．e-c-b-a-d C．c-e-a-d-b D．e-b-a-c-d4．Why did Pooh appear in Doc McStuffins?A．To meet a guest in this program. B．To be a special part of this program.C．To show it is also a popular program. D．To make its new film known to people.5．What does the passage mainly about?A．Pooh and his friends B．Great success of PoohC．Pooh's influence on culture D．The real story behind PoohC15、Let children learn to judge their own work. A child learning to talk does not learn by being corrected all the time; if corrected too much, he will stop talking. He notices a thousand times a day the difference between the languages he uses and the language those around him use. Bit by bit, he makes the necessary changes to make his language like other people.In the same way, when children learn to do all the other things, they learn to do without being taught-to walk, run, climb, whistle, ride a bicycle-compare those performances with those of more skilled people, and slowly make the needed changes. But in school we never give a child a chance to find out his own mistakes for himself, let alone correct them. We do it all for him. We act as if we thought that he would never notice a mistake unless it was pointed out to him, or correct it unless he was made to. Soon he becomes dependent on the teacher. Let him do it himself. Let him work out, with the help of other children if he wants it, what this word says, what answer is to that problem, whether this is a good way of saying or doing this or not.If it is a matter of right answers, as it may be in mathematics or science, give him the answer book. Let him correct his own papers. Why should we teachers waste time on such routine work？Our job should be to help the child when he tells us that he can’t find the way to get the right answer. Let’s end this nonsense of grades, exams, marks. Let us throw them all out, and let the children learn what all educated persons must some day learn, how to measure their own understanding, how to know what they know or do not know.1．What does the author think is the best way for children to learn things？A．by copying what other people doB．by making mistakes and having them correctedC．by listening to explanations from skilled peopleD．by asking a great many questions2．According to the writer, teachers in school should _____A．allow children to learn from each otherB．point out children’s mistakes whenever foundC．correct children’s mistakes as soon as possibleD．give children more book knowledge3．The passage suggests that learning to speak and learning to ride a bicycle are___.A．not really important skills B．more important than other skillsC．basically different from learning adult skills D．basically the same as learning other skills4．Exams, grades, and marks should be abolished because c hildren’s progress should only be estimated by___. A．educated persons B．the children themselves C．teachers D．parentsD16、Once a week, Neil went grocery shopping. He always made a list, but he always forgot to put one or more things on the list. T his used to anger him, but now he just accepted it. You’re not as sharp as you used to be, he told himself.It was Friday-shopping day. He went to the $99 Store. Sometimes they had a lot of fresh produce, sometimes they didn’t. He got lucky. There were fresh packaged broccoli, carrots, onions, and squash. Also, packages of peaches, plums, and apples. He easily had enough produce to last all week, if it didn’t go bad first. The fruit and vegetables alone filled up four plastic bags. Four other bags contained other items that were on Neil’s list.He drove to Albertson’s, which sold milk by the gallon (加仑) and at cheaper prices than the $99 Store. Interestingly, the price of milk had got higher in the last month. He used to buy 2 gallons of nonfat milk for $3.59. Now he was paying $4.69. Yet, the news media reports a 2-cent increase in gasoline (汽油) prices. That’s all over the news.He parked his car in the carport and opened the trunk. He managed, as usual, to put all 10 plastic bags into his hands and take them upstairs.“What a heavy shopping it is,” he thought. And then he told himself: if you think it’s too heavy now, wait till you can’t drive. Wait till you can’t even walk up the stairs. How are you going to get your food then? The older you get, he toldhi mself, the more you’d better thank the fact that you can still do all these boring chores and housework.1．Neil always made _______ before he went shopping.A．a list B．a plastic bag C．a car D．a report2．Neil didn’t buy _____ at the $99 Store.A．broccoli B．peaches C．apples D．milk3．How much did one gallon of nonfat milk cost that day?A．$3.59. B．$4.69. C．About $2.35. D．About $1.80.4．How many bags of things did Neil buy?A．Ten. B．Nine. C．Eight. D．Four.5．What can we learn from Neil?A．We should thank what we can still do.B．We should eat enough fruit and vegetables.C．We all will get old one day.D．Buying cheap things can make us happyE17、Everyone has got two personalities (性格)—the one that is shown to the world and the other that is secret and real. You do n’t show your secret personality when you're awake because you can control yourself, but when you're asleep, your sleeping position shows the real you. In a normal night, of course, you often change your sleeping positions. The important position that best shows your secret personality is the one that you go to sleep.If you go to sleep on your back, you're a very open person. You normally trust people and you are easily influenced by new ideas. You don’t like to make people unhappy, so you never expre ss your real feelings. You're quite shy and you aren't very confident.If you sleep on your stomach, you are a person who likes to keep secrets. You worry a lot and you're always easily becoming sad. You never want to change your ideas, but you are satisfied with your life the way it is. You usually live for today not for tomorrow.If you sleep on curled up (蜷缩) , you are probably a very nervous person. You have a low opinion of yourself and often protect yourself from being hurt, so you are very defensive. You're shy and you don't usually like meeting people. You like to be on your own.If you sleep on your side, you have usually got a well-balanced (平衡的) personality. You know your strengths and weaknesses. You're usually careful. You have a confident personality. You sometimes feel worried, but you don't often get unhappy. Y ou always say what you think, even if it makes people angry.1．You may find the passage in __________.A．a science magazine B．a guide book C．a sports newspaper D．a story book2．When does the sleeping position best show your secret personality?A．In the daytime. B．At the beginning of sleep. C．At night. D．During the deep sleep. 3．Tina hardly tells her secrets to her friends. She probably goes to sleep __________.A．on curled up B．on her stomach C．on her back D．on her side4．What does the word “defensive" mean in the passage?A．易怒的B．攻击性的C．外向的D．有戒心的5．What does the passage tell us?A．Sleeping on your side is the best way of sleeping.B．Changing positions will cause sleeping problems.C．Sleeping positions show people's secret personalities.D．Enough sleep makes people look better and healthier.F18、Dick lived in England. One day in January he said to his wife，“I'm going to fly to New York next week because I've got some work there.” “Where are you going to stay there？” his wife asked. “I don't know yet.” Dick answered. “Please send me your address from there in a telegram(电报)，”his wife said. “All right，” Dick answered.He flew to New York on January 31st and found a nice hotel in the center of the city. He put his things in his room and then he sent his wife a telegram. He put the address of his hotel in it.In the evening he didn't have any work，so he went to a cinema. He came out at nine o'clock and said，“Now I'm going b ack to my hotel and have a nice dinner.”He found a taxi and the driver said，“Where do you want to go？” But Dick didn't remember the name and address of his hotel.“Which hotel are my things in？” he said. “And what am I going to do tonight？” But the driver of the taxi did not know. So Dick got out and went into a post office. There he sent his wife another telegram，and in it he wrote，“Please send me my address at this post office.”1．Dick flew to New York because ________．A．he went there for a holiday B．he had work thereC．he went there for sightseeing(观光) D．his home was there2．Who would send him the name and address of his hotel?A．The manager(经理)of his hotel. B．The police office.C．The taxi driver. D．His wife.3．Which of the following is NOT true?A．Dick stayed at a nice hotel in the center of the city.B．Dick didn't work on the first night of his arrival.C．Dick forgot to send his wife a telegram.D．Dick wanted to go back to his hotel in a taxi.Ⅴ.书面表达19、李华的哥哥在MH370失联飞机中遇难，到现在一直还很伤心，总是一个人呆在房间，不和别人说话, 请你以王强的名义写一封信给他，给他一些建议，鼓励他振作起来。

相依序列均值和方差变点的估计

相依序列均值和方差变点的估计王慧敏;贺兴时;赵文芝【摘要】The linear dependent sequences estimate problem of mean-variance change-points exist at the same times is studied by establishing the statistical model and constracting the CUSUM statistics of mean and variance change points are.Considering the effect of mean change point,by calculating the convergence speed of mean change point estimator,two different cases of variance change points of mean and the mean change point known and unknown are analyzed,and the convergence speed of variance change point estimators are also calculated.%通过建立统计模型,构造均值、方差变点位置的CUSUM型估计量,研究线性相依序列均值方差同时存在变点的估计问题.考虑均值变点对方差变点的影响,通过均值变点估计量的收敛速度,在均值及均值变点已知与未知两种情况下分别分析方差变点问题,推导出方差变点估计量的收敛速度.【期刊名称】《纺织高校基础科学学报》【年(卷),期】2017(030)002【总页数】6页(P220-225)【关键词】相依序列;变点问题;CUSUM估计;收敛速度【作者】王慧敏;贺兴时;赵文芝【作者单位】西安工程大学理学院,陕西西安 710048;西北工业大学理学院,陕西西安 710072;西安工程大学理学院,陕西西安 710048;西安工程大学理学院,陕西西安 710048【正文语种】中文【中图分类】O212.1Abstract：The linear dependent sequences estimate problem of mean－variance change－points exist at the same times is studied by establishing the statistical model and constracting the CUSUM statistics of mean and variance change points are．Considering the effect of mean change point，by calculating the convergence speed of mean change point estimator，two different cases of variance change points of mean and the mean change point known and unknown are analyzed，and the convergence speed of variance change point estimators are also calculated．Key words：dependent sequence；change－point problem；CUSUM estimation；rate of convergence自20世纪70年代变点问题一直是统计学的一个热门话题［1－4］，1954年Page［5］在国际著名的统计杂志《Biometrika》上发表了第一篇关于变点统计分析的文章，研究自动生产线上产品质量检测问题．当产品质量超过产品质量控制警戒线时，希望能及时预报，以免生产出更多的次品．Yao［6］考虑样本容量为N时，变点位置τ0的极大似然估计，研究了独立随机变量正态分布下变点的近似分布情况，但对于非正态情况的近似分布未做研究．Bhattacharya［7］利用ML －Estimate（最大似然估计法）研究了多参数下正态情形独立序列｛ξk，－∞＜k＜∞｝，＝0，τ2的均值变点的估计，考虑逼近真实参数值时似然函数的行为，对方差变点未作出分析．Csrgǒ等［8］对极大似然比方法做了详细描述并深入研究变点统计分析的极限理论及其性质，考虑了所有参数均假设未知情况下的似然比统计量变点问题，是对这一领域近20年理论研究的总结．目前，变点问题的研究主要集中在对独立序列均值、方差变点的统计推断及应用方面［9－11］，而在对相依序列的变点问题研究中关于方差变点方面的成果还不是很多［12－13］．Hariz 等［14］对长相依过程中均值变点进行研究，并将结论用于短记忆过程．Kokoszka等［15］用CUSUM方法对方差有限的相依随机变量序列的均值变点进行了估计，但未给出方差变点问题的研究．Potarakis［16］用最小二乘法对回归模型的变点问题进行估计，但在处理参数与计算量问题中存在较大困难，未能给出估计量的收敛速度．而在实际观测数据中往往会出现均值和方差同时存在变点的问题，并且两种变点出现时刻有可能不相同的情况，所以关于相依序列中均值与方差同时存在的变点问题的研究有重要的理论与应用价值．文中通过建立线性相依序列统计模型，构造均值、方差变点位置的CUSUM型统计量，研究相依序列均值与方差同时存在变点的问题．对于方差变点问题考虑均值变点对其影响，分别在均值及均值变点已知与未知两种不同情形下计算出均值、方差变点的收敛速度．考虑如下随机变量序列μ1和μ2，σ1和σ2均已知；k0为未知的均值变点；k1为μ1，μ2，k0已知时未知的方差变点．假设1 （1）εt，t＝1，2，…，n是均值为0方差为1的i．i．d．序列；（2）｜aj｜＜∞；（3）对任意的t均有E｜εt｜4＜∞．引理1［17］在假设1的（1），（2）成立条件下，对于只依靠aj的常数C0＜∞，Ha′jek－Re′nyi不等式有如下形式：2．1 均值变点估计的收敛速度证明对线性相依序列｛Yt｝均值变点k0的CUSUM估计为由于对称性，式（4）只考虑右边第一部分．又因为2．2 方差变点估计的收敛速度证明当均值及均值变点已知时，定义方差变点k1的CUSUM估计量＾k1为当均值及均值变点未知时，对于均值μ未知的情况，先估计μ，使用如下估计：从而关于方差变点的CUSUM估计定义为证明由线性过程的中心极限定理知对线性相依序列变点理论进行分析，考虑均值及方差都存在变点并且变点时刻不同的变点估计问题．分别构造了均值、方差变点位置的CUSUM型统计量，在各估计量满足相合性的前提下，得到了均值变点位置的估计量的收敛速度为T－1．研究了均值变点对方差变点的影响，分别在均值及均值变点已知与未知两种不同情形下证明了方差变点位置的估计量，的收敛速度为T－1，进一步说明了变点估计量的有效性．【相关文献】［1］ HORVTH L，KOKOSZKA P．The effect of long range dependence on change point estimators［J］．Journal of Statistical Planning and Inference，1997，64（1）：57－81．［2］张立文，周秀轻．混合序列均值变点的收敛速度研究［J］．南京大学学报，2011，28（1）：97－105．ZHANG Liwen，ZHOU xiuqing．Research on the convergence of the estimator for the change point in the mean of mixing random sequences［J］．Journal of Nanjing University Mathematical Biquarterly，2011，28（1）：97－105．［3］谭常春，汤安勇，张虎．变点估计的相合性及其应用［J］．统计与决策，2012，21：30－32．TAN Changchun，TANG Anyong，ZHANG Hu．Consistency and its application of change point estimation［J］．Statistics and Decision，2012，21：30－32．［4］赵文芝，吕会琴．厚尾相依序列均值变点Ratio检验［J］．山西大学学报（自然科学版），2016，39（3）：410－414．ZHAO Wenzhi，LYU Huiqin．Ratio test for change point in the mean of heavy－tailed dependent squence［J］．Journal ofShanxi University （Naturel Science Edition），2016，39（3）：410－414．［5］ PAGE E S．Continuous inspection schemes［J］．Biometrika，1954，42：100－114．［6］ YAO Y C．Approximating the distribution of the ML estimate of the change－pointin a sequence of independent random variables［J］．Annals of Statistics，1987，3（6）：1321－1328．［7］ BHATTCHARYA P K．Maximum likelihood estimation of a change－point in the dis－tribution of independent random variables：General multiparameter case［J］．Multi－variate Analysis，1987，23（2）：183－208．［8］ CSRG，HORCCH．Limit theorems in change－points analysis［M］．New York：John Wiley ＆Sons，1997：1－378．［9］ YAO Y C，RICHARD A D．The asymptotic behavior of the likelihood ratio statisticfor testing a shift in mean in a sequence of independent normal variates［J］．Journal of Statistics，1986，48（3）：339－353．［10］邵钏．关于方差变点问题的几个统计推断［D］．杭州：浙江大学，2012：4－24．SHAO Chuan．Some inference about change in variance［D］．Hangzhou：Zhejiang University，2012：4－24．［11］ LEE S，NA S．Test for parameter change in stochastic processes based on conditional least－squares estimator［J］．Journal of Multivariate Analysis，2005，93（2）：375－393．［12］孙耀东，徐宝，赵志文．相依误差下非参数回归模型的方差变点Ratio检验［J］．江西师范大学学报（自然科学版），2013，37（5）：471－474．SUN Yaodong，XU Bao，ZHAO Zhiwen．The ratio test for change point detection in nonparametric regression modelwith dependent errors［J］．Journal of Jiangxi Normal University（Natural Science），2013，37（5）：471－474．［13］金浩，张思，乔宝明．基于Bootstrap的厚尾相依序列持久性变点检验［J］．数学的实践与认识，2012，42（13）：174－179．JIN Hao，ZHANG Si，QIAO Baoming．Bootstrap testing for persistence changes with heavy－tailed dependent sequences ［J］．Mathematics in Practice and Theory，2012，42（13）：174－179．［14］ HARIZ S B，WYLIE J J．Rates of convergence for the change－point estimator for long range dependent sequences［J］．Statistics and Probability Letters，2005，73：155－164．［15］ KOKOSZKA P，LEIPUS R．Change－point in the mean of dependent observations ［J］．Statistics and Probability Letters，1998，40（4）：385－393．［16］ POTARAKIS J Y．Least squares estimation and tests of breaks in mean and variance under mis－specification［J］．E－conometrics，2004，7（1）：32－54．［17］ BAI J．Least squares estimation of a shift in linear processes［J］．Massachusetts Institute of Technology，1993，15（5）：453－472．［18］王慧敏，贺兴时，赵文芝．变点统计分析及实例研究［J］．电子测试，2013，9（18）：38－40．WANG Huimin，HE Xingshi，ZHAO Wenzhi．The statistical analysis and case study of change point［J］．Electronic Test，2013，9（18）：38－40．。

(完整版)托福TPOextra答案解析和原文翻译

TPO 34阅读解析第一篇Population and Climate【P1】地球人口的增长已经对大气和生态环境产生了影响。

化石燃料的燃烧，毁林，城市化，种植大米，养殖家畜，生产作为助推燃料和制冷剂的CFC增加了空气中CO2，甲烷，二氧化氮，二氧化硫灰尘和CFOs 的含量。

约70%的太阳能量穿过大气直射地球表面。

太阳射线提高了土地和海洋表面的温度，随后土地和海洋表面将红外射线反射会太空中。

这能使地球避免温度过高。

但是并不是所有的红外射线被返回会太空中，一些被大气中的气体吸收，然后再次反射回地球表面。

温室气体就是其中吸收了红外射线的一种气体，然后再次反射一些红外线到地球。

二氧化碳，CFC，甲烷和二氧化氮都是温室气体。

大气中温室效应形成和建立的很自然。

事实上，大气中如果没有温室气体，科学家预测地球温度比当前的能够低33度。

【P2】大气中当前二氧化碳浓度是360ppm。

人类活动正在对大气中二氧化碳浓度的增加有着重要的影响，二氧化碳浓度正在快速增长，目前预估在未来50-100年内，浓度将是目前的一倍。

IPCC在1992中做出一份报告，在该份报告中大多数大气科学家中观点一致，预测二氧化碳浓度翻倍可能会将全球气温提高1.4-4.5度。

IPCC在2001年的报告中做出的预测是气温几乎将会提高2倍。

可能发生的气温升高比在冰河时期发生的变化要大很多。

这种温度的升高也不会是一直的，在赤道周围变化最小，而在极点周围的变化则是2-3倍。

这些全球变化的本地化影响很难预测，但是大家一致认为可能会影响洋流的改变，在北半球的一些区域可能增加在冬天发洪水的可能性，在一些区域夏天发生干旱的概率提高，还有海平面的升高也可能会淹没位置较低的国家。

【P3】科学家积极参与地球气候系统中物理，化学和生物成分的调查，为了对温室气体的增加对未来全球气候的影响做出准确预测。

全球环流模型在这个过程中是重要的工具。

这些模型体现包含了当前对大气环流模式，洋流，大陆影响和类似东西所掌握的知识，在变化的环境下预测气候。

Single Variable Calculus_中国大学mooc课后章节答案期末考试题库2023年

Single Variable Calculus_西北工业大学中国大学mooc课后章节答案期末考试题库2023年1.If f (x) and g (x) are differentiable on (a, b), 【图片】and f (x) > 0, g (x) > 0,x∈(a, b), then when x∈(a, b), we have答案:2.For what values of a and b will 【图片】be differentiable for all values of x?答案:a=-1/2, b=13.The evaluation of integral【图片】(where x>1) is答案:4.Find the derivative of【图片】答案:5.Find the centroid of a thin, flat plate covering the “triangular” region i n thefirst quadrant bounded by they-axis, the parabola【图片】, and the line【图片】.答案:6.If【图片】, find the limit of g(x) as x approaches the indicated value.答案:7.Find the derivative of the function below at x=0,【图片】答案:8.【图片】is答案:-1/329.If f (x) is continuous and F′(x) = f(x), then答案:10.Find the volume of the solid generated by revolving the region bounded bythe curve【图片】and the lines【图片】about【图片】.答案:11.The mean value【图片】that satisfies the Rolle’s Theorem on the function【图片】is答案:12.The critical number of 【图片】is ( )答案:0 and 213.Which statement is true?【图片】答案:A14.If【图片】,then【图片】答案:15.Evaluate【图片】.答案:16.The integtral of【图片】is答案:17.When x approaches infinity, the limit of【图片】is答案:18.The evaluation of integral【图片】is答案:19.If【图片】has continuous second-order derivative, and【图片】, then答案:20.Find the length of the enclosed loop【图片】shown here. The loop starts at【图片】and ends at【图片】.【图片】答案:21.The height of a body moving vertically is given by 【图片】, with s in metersand t in se conds. The body’s maximum height is ( )答案:22.If f (x) is increasing and f(x) > 0, then答案:23. A rock climber is about to haul up 100 N of equipment that has been hangingbeneath her on 40 m of rope that weighs 0.8 newton per meter. How much work will it take? (Hint: Solve for the rope and equipment separately, thenadd.)答案:24.The integral of【图片】is答案:25.Expand【图片】by partial function答案:26.Assume that u is a function of x and v is the derivative of u, then thederivative of arcsin(u) is答案:27.Find the center of mass of a thin plate covering the region bounded below bythe parabola 【图片】and above by the line 【图片】, if the density at the point 【图片】is 【图片】.答案:28.Find the limit【图片】答案:-129.Find the length of the curve【图片】, from【图片】 to【图片】.答案:53/630.Find the volume of the solid generated by revolving the regions bounded bythe curve 【图片】and line 【图片】about the x-axis.答案:31.Find the total area of the shaded region in the following picture.【图片】答案:4/332.The total area between the region 【图片】and the x-axis is答案:33.Which statement is NOT true?答案:34.Calculate【图片】答案:-135.The second derivative of the function y=secx is ( )答案:36.If gas in a cylinder is maintained at a constant temperature T, the pressure Pis related to the volume V by a formula of the form 【图片】in which a, b, n, and R are constants. Then【图片】答案:37.If【图片】then【图片】.答案:38.Calculate 【图片】The limit is ( )答案:139.Find the tangent to the folium of descartes 【图片】at the point (3,3)答案:x+y=640.Let 【图片】The tangent line to the graph of g(x) at (0,0) is ( ).答案:x-axis41.Find the derivative of the function below at x=0, 【图片】答案:It does not exist42.Find【图片】答案:43.The average value of 【图片】over theinterval [【图片】] is答案:44.Find the average rate of change of the function【图片】over the giveninterval [2,3]答案:1945.For【图片】 find the number【图片】 by using the two steps learned in 2.3.答案:0.0546.The linearization of the function 【图片】at x=1 is ( ).答案:47.If and only if x=ln(y),y=e^x.答案:正确48.Find the derivative of the function【图片】答案:49.Find the derivative of the function 【图片】It is ( )答案:50.If f (x) is an antiderivative of【图片】then【图片】答案:51.If f ′(x ) < 0, f ′′(x ) < 0, x∈(a, b), then the graph of f (x) on (a, b) is答案:decreasing and concave down.52.If【图片】, find【图片】.答案:753.At what points are the function【图片】 continuous?答案:Discontinuous at odd integer multiples of , but continuous at all other x.54.On what interval is the function 【图片】continuous?答案:55.On what interval is the function【图片】continuous?答案:56.【图片】【图片】and【图片】答案:0, 357.Suppose that the functionf(x)is second order continuous differentiable, and【图片】,【图片】. Therefore,【图片】答案:58.When x approaches 0, the limit of【图片】is答案:59.Find the area of the surface generated by revolving the curve 【图片】aboutthe x-axis to generate a solid.答案:60.Find the average rate of change of the function【图片】 over the giveninterval [0,2]答案:161.Find the limit of the function【图片】 and is the function continuous at thepoint being approached?答案:The limit is 0 and the function is continuous at62.The integral of [x/(x^2+1)]dx is答案:1/2[ln(x^2+1)]+C63.When x approaches 0, the limit of (1+3x)^(1/x) is答案:e^364.When x approaches infinity, the limit of x^(1/x) is答案:165.When x approaches infinity, for two functions f(x) and g(x), the limit off(x)/g(x) is infinity, and the limit of g(x)/f(x) is 0, thus a relationship between their growth rates can be said that答案:Function f(x) grouws faster than g(x).66. A function f is called a One-to-One function if it never takes on the same valuetwice.答案:正确67.The integtral of [e^(2x+1)]dx is答案:1/2[e^(2x+1)]+C68. A force of 2 N will stretch a rubber band 2 cm (0.02 m). Assuming thatHooke's Law applies, how far will a 4-N force stretch the rubber band?答案:4 cm69.Find the area of the surface generated by revolving the curve【图片】aboutthey-axis.答案:70.Which statement is true?答案:71.Which statement is false?答案:72.Find the integration formula of the solid volume generated by the curve 【图片】, the x-axis, and the line 【图片】revolved about the x-axis by the shell method.答案:73.Find the integration formula of the area of the region bounded above by thecurve 【图片】, below by the curve 【图片】, on the left by 【图片】, and on the right by 【图片】.答案:74.If 【图片】is continuous on [-1,1] and the average value is 2, then 【图片】答案:475. A cubic function is a polynomial of degree 3; that is, it has the form 【图片】，where a≠0. Then ( ) is false.答案:x=1 is critical number when the cubic function has only one criticalnumber.76.The graph of【图片】has ( )asymptotes.答案:377.If 【图片】then答案:78.The average value of【图片】on【图片】is答案:79.If f (x) is continuous on (−1, 1), and【图片】then答案:80.The derivative of the function【图片】 is答案:81.The function 【图片】has ( )答案:A. neither a local maximum nor a local minimum82.Find the derivative of function【图片】答案:83.Find y' , if【图片】答案:84.The derivative of 【图片】is( )答案:85.Let【图片】,Then【图片】答案:18x(x+1)86.At what points, is the function 【图片】continuous?答案:A. Discontinuous only when x= 3 or x= 187.Find the derivative of x(e^x).答案:e^x(x+1)88.The integral of (1/x)dx is答案:ln|x|+C89.Find the area of the surface generated by revolving the curve 【图片】aboutthe y-axis to generate a solid.答案:90.Find the length of the curve【图片】.答案:7ing the trapezoidal rule to estimate the integralwith n=4 steps【图片】答案:0.70500。

AI专用词汇

AI专⽤词汇LetterAAccumulatederrorbackpropagation累积误差逆传播ActivationFunction激活函数AdaptiveResonanceTheory/ART⾃适应谐振理论Addictivemodel加性学习Adversari alNetworks对抗⽹络AffineLayer仿射层Affinitymatrix亲和矩阵Agent代理/智能体Algorithm算法Alpha-betapruningα-β剪枝Anomalydetection异常检测Approximation近似AreaUnderROCCurve／AUCRoc曲线下⾯积ArtificialGeneralIntelligence/AGI通⽤⼈⼯智能ArtificialIntelligence/AI⼈⼯智能Associationanalysis关联分析Attentionmechanism注意⼒机制Attributeconditionalindependenceassumption属性条件独⽴性假设Attributespace属性空间Attributevalue属性值Autoencoder⾃编码器Automaticspeechrecognition⾃动语⾳识别Automaticsummarization⾃动摘要Aver agegradient平均梯度Average-Pooling平均池化LetterBBackpropagationThroughTime通过时间的反向传播Backpropagation/BP反向传播Baselearner基学习器Baselearnin galgorithm基学习算法BatchNormalization/BN批量归⼀化Bayesdecisionrule贝叶斯判定准则BayesModelAveraging／BMA贝叶斯模型平均Bayesoptimalclassifier贝叶斯最优分类器Bayesiandecisiontheory贝叶斯决策论Bayesiannetwork贝叶斯⽹络Between-cla ssscattermatrix类间散度矩阵Bias偏置/偏差Bias-variancedecomposition偏差-⽅差分解Bias-VarianceDilemma偏差–⽅差困境Bi-directionalLong-ShortTermMemory/Bi-LSTM双向长短期记忆Binaryclassification⼆分类Binomialtest⼆项检验Bi-partition⼆分法Boltzmannmachine玻尔兹曼机Bootstrapsampling⾃助采样法／可重复采样／有放回采样Bootstrapping⾃助法Break-EventPoint／BEP平衡点LetterCCalibration校准Cascade-Correlation级联相关Categoricalattribute离散属性Class-conditionalprobability类条件概率Classificationandregressiontree/CART分类与回归树Classifier分类器Class-imbalance类别不平衡Closed-form闭式Cluster簇/类/集群Clusteranalysis聚类分析Clustering聚类Clusteringensemble聚类集成Co-adapting共适应Codin gmatrix编码矩阵COLT国际学习理论会议Committee-basedlearning基于委员会的学习Competiti velearning竞争型学习Componentlearner组件学习器Comprehensibility可解释性Comput ationCost计算成本ComputationalLinguistics计算语⾔学Computervision计算机视觉C onceptdrift概念漂移ConceptLearningSystem/CLS概念学习系统Conditionalentropy条件熵Conditionalmutualinformation条件互信息ConditionalProbabilityTable／CPT条件概率表Conditionalrandomfield/CRF条件随机场Conditionalrisk条件风险Confidence置信度Confusionmatrix混淆矩阵Connectionweight连接权Connectionism连结主义Consistency⼀致性／相合性Contingencytable列联表Continuousattribute连续属性Convergence收敛Conversationalagent会话智能体Convexquadraticprogramming凸⼆次规划Convexity凸性Convolutionalneuralnetwork/CNN卷积神经⽹络Co-oc currence同现Correlationcoefficient相关系数Cosinesimilarity余弦相似度Costcurve成本曲线CostFunction成本函数Costmatrix成本矩阵Cost-sensitive成本敏感Crosse ntropy交叉熵Crossvalidation交叉验证Crowdsourcing众包Curseofdimensionality维数灾难Cutpoint截断点Cuttingplanealgorithm割平⾯法LetterDDatamining数据挖掘Dataset数据集DecisionBoundary决策边界Decisionstump决策树桩Decisiontree决策树／判定树Deduction演绎DeepBeliefNetwork深度信念⽹络DeepConvolutionalGe nerativeAdversarialNetwork/DCGAN深度卷积⽣成对抗⽹络Deeplearning深度学习Deep neuralnetwork/DNN深度神经⽹络DeepQ-Learning深度Q学习DeepQ-Network深度Q⽹络Densityestimation密度估计Density-basedclustering密度聚类Differentiab leneuralcomputer可微分神经计算机Dimensionalityreductionalgorithm降维算法D irectededge有向边Disagreementmeasure不合度量Discriminativemodel判别模型Di scriminator判别器Distancemeasure距离度量Distancemetriclearning距离度量学习D istribution分布Divergence散度Diversitymeasure多样性度量／差异性度量Domainadaption领域⾃适应Downsampling下采样D-separation（Directedseparation）有向分离Dual problem对偶问题Dummynode哑结点DynamicFusion动态融合Dynamicprogramming动态规划LetterEEigenvaluedecomposition特征值分解Embedding嵌⼊Emotionalanalysis情绪分析Empiricalconditionalentropy经验条件熵Empiricalentropy经验熵Empiricalerror经验误差Empiricalrisk经验风险End-to-End端到端Energy-basedmodel基于能量的模型Ensemblelearning集成学习Ensemblepruning集成修剪ErrorCorrectingOu tputCodes／ECOC纠错输出码Errorrate错误率Error-ambiguitydecomposition误差-分歧分解Euclideandistance欧⽒距离Evolutionarycomputation演化计算Expectation-Maximization期望最⼤化Expectedloss期望损失ExplodingGradientProblem梯度爆炸问题Exponentiallossfunction指数损失函数ExtremeLearningMachine/ELM超限学习机LetterFFactorization因⼦分解Falsenegative假负类Falsepositive假正类False PositiveRate/FPR假正例率Featureengineering特征⼯程Featureselection特征选择Featurevector特征向量FeaturedLearning特征学习FeedforwardNeuralNetworks/FNN前馈神经⽹络Fine-tuning微调Flippingoutput翻转法Fluctuation震荡Forwards tagewisealgorithm前向分步算法Frequentist频率主义学派Full-rankmatrix满秩矩阵Func tionalneuron功能神经元LetterGGainratio增益率Gametheory博弈论Gaussianker nelfunction⾼斯核函数GaussianMixtureModel⾼斯混合模型GeneralProblemSolving通⽤问题求解Generalization泛化Generalizationerror泛化误差Generalizatione rrorbound泛化误差上界GeneralizedLagrangefunction⼴义拉格朗⽇函数Generalized linearmodel⼴义线性模型GeneralizedRayleighquotient⼴义瑞利商GenerativeAd versarialNetworks/GAN⽣成对抗⽹络GenerativeModel⽣成模型Generator⽣成器Genet icAlgorithm/GA遗传算法Gibbssampling吉布斯采样Giniindex基尼指数Globalminimum全局最⼩GlobalOptimization全局优化Gradientboosting梯度提升GradientDescent梯度下降Graphtheory图论Ground-truth真相／真实LetterHHardmargin硬间隔Hardvoting硬投票Harmonicmean调和平均Hessematrix海塞矩阵Hiddendynamicmodel隐动态模型H iddenlayer隐藏层HiddenMarkovModel/HMM隐马尔可夫模型Hierarchicalclustering层次聚类Hilbertspace希尔伯特空间Hingelossfunction合页损失函数Hold-out留出法Homo geneous同质Hybridcomputing混合计算Hyperparameter超参数Hypothesis假设Hypothe sistest假设验证LetterIICML国际机器学习会议Improvediterativescaling/IIS改进的迭代尺度法Incrementallearning增量学习Independentandidenticallydistributed/i.i.d.独⽴同分布IndependentComponentAnalysis/ICA独⽴成分分析Indicatorfunction指⽰函数Individuallearner个体学习器Induction归纳Inductivebias归纳偏好I nductivelearning归纳学习InductiveLogicProgramming／ILP归纳逻辑程序设计Infor mationentropy信息熵Informationgain信息增益Inputlayer输⼊层Insensitiveloss不敏感损失Inter-clustersimilarity簇间相似度InternationalConferencefor MachineLearning/ICML国际机器学习⼤会Intra-clustersimilarity簇内相似度Intrinsicvalue固有值IsometricMapping/Isomap等度量映射Isotonicregression等分回归It erativeDichotomiser迭代⼆分器LetterKKernelmethod核⽅法Kerneltrick核技巧K ernelizedLinearDiscriminantAnalysis／KLDA核线性判别分析K-foldcrossvalidationk折交叉验证／k倍交叉验证K-MeansClusteringK–均值聚类K-NearestNeighb oursAlgorithm/KNNK近邻算法Knowledgebase知识库KnowledgeRepresentation知识表征LetterLLabelspace标记空间Lagrangeduality拉格朗⽇对偶性Lagrangemultiplier拉格朗⽇乘⼦Laplacesmoothing拉普拉斯平滑Laplaciancorrection拉普拉斯修正Latent DirichletAllocation隐狄利克雷分布Latentsemanticanalysis潜在语义分析Latentvariable隐变量Lazylearning懒惰学习Learner学习器Learningbyanalogy类⽐学习Learn ingrate学习率LearningVectorQuantization/LVQ学习向量量化Leastsquaresre gressiontree最⼩⼆乘回归树Leave-One-Out/LOO留⼀法linearchainconditional randomfield线性链条件随机场LinearDiscriminantAnalysis／LDA线性判别分析Linearmodel线性模型LinearRegression线性回归Linkfunction联系函数LocalMarkovproperty局部马尔可夫性Localminimum局部最⼩Loglikelihood对数似然Logodds／logit对数⼏率Lo gisticRegressionLogistic回归Log-likelihood对数似然Log-linearregression对数线性回归Long-ShortTermMemory/LSTM长短期记忆Lossfunction损失函数LetterM Machinetranslation/MT机器翻译Macron-P宏查准率Macron-R宏查全率Majorityvoting绝对多数投票法Manifoldassumption流形假设Manifoldlearning流形学习Margintheory间隔理论Marginaldistribution边际分布Marginalindependence边际独⽴性Marginalization边际化MarkovChainMonteCarlo/MCMC马尔可夫链蒙特卡罗⽅法MarkovRandomField马尔可夫随机场Maximalclique最⼤团MaximumLikelihoodEstimation/MLE极⼤似然估计／极⼤似然法Maximummargin最⼤间隔Maximumweightedspanningtree最⼤带权⽣成树Max-P ooling最⼤池化Meansquarederror均⽅误差Meta-learner元学习器Metriclearning度量学习Micro-P微查准率Micro-R微查全率MinimalDescriptionLength/MDL最⼩描述长度Minim axgame极⼩极⼤博弈Misclassificationcost误分类成本Mixtureofexperts混合专家Momentum动量Moralgraph道德图／端正图Multi-classclassification多分类Multi-docum entsummarization多⽂档摘要Multi-layerfeedforwardneuralnetworks多层前馈神经⽹络MultilayerPerceptron/MLP多层感知器Multimodallearning多模态学习Multipl eDimensionalScaling多维缩放Multiplelinearregression多元线性回归Multi-re sponseLinearRegression／MLR多响应线性回归Mutualinformation互信息LetterN Naivebayes朴素贝叶斯NaiveBayesClassifier朴素贝叶斯分类器Namedentityrecognition命名实体识别Nashequilibrium纳什均衡Naturallanguagegeneration/NLG⾃然语⾔⽣成Naturallanguageprocessing⾃然语⾔处理Negativeclass负类Negativecorrelation负相关法NegativeLogLikelihood负对数似然NeighbourhoodComponentAnalysis/NCA近邻成分分析NeuralMachineTranslation神经机器翻译NeuralTuringMachine神经图灵机Newtonmethod⽜顿法NIPS国际神经信息处理系统会议NoFreeLunchTheorem ／NFL没有免费的午餐定理Noise-contrastiveestimation噪⾳对⽐估计Nominalattribute列名属性Non-convexoptimization⾮凸优化Nonlinearmodel⾮线性模型Non-metricdistance⾮度量距离Non-negativematrixfactorization⾮负矩阵分解Non-ordinalattribute⽆序属性Non-SaturatingGame⾮饱和博弈Norm范数Normalization归⼀化Nuclearnorm核范数Numericalattribute数值属性LetterOObjectivefunction⽬标函数Obliquedecisiontree斜决策树Occam’srazor奥卡姆剃⼑Odds⼏率Off-Policy离策略Oneshotlearning⼀次性学习One-DependentEstimator／ODE独依赖估计On-Policy在策略Ordinalattribute有序属性Out-of-bagestimate包外估计Outputlayer输出层Outputsmearing输出调制法Overfitting过拟合／过配Oversampling过采样LetterPPairedt-test成对t检验Pairwise成对型PairwiseMarkovproperty成对马尔可夫性Parameter参数Parameterestimation参数估计Parametertuning调参Parsetree解析树ParticleSwarmOptimization/PSO粒⼦群优化算法Part-of-speechtagging词性标注Perceptron感知机Performanceme asure性能度量PlugandPlayGenerativeNetwork即插即⽤⽣成⽹络Pluralityvoting相对多数投票法Polaritydetection极性检测Polynomialkernelfunction多项式核函数Pooling池化Positiveclass正类Positivedefinitematrix正定矩阵Post-hoctest后续检验Post-pruning后剪枝potentialfunction势函数Precision查准率／准确率Prepruning预剪枝Principalcomponentanalysis/PCA主成分分析Principleofmultipleexplanations多释原则Prior先验ProbabilityGraphicalModel概率图模型ProximalGradientDescent/PGD近端梯度下降Pruning剪枝Pseudo-label伪标记LetterQQuantizedNeu ralNetwork量⼦化神经⽹络Quantumcomputer量⼦计算机QuantumComputing量⼦计算Quasi Newtonmethod拟⽜顿法LetterRRadialBasisFunction／RBF径向基函数RandomFo restAlgorithm随机森林算法Randomwalk随机漫步Recall查全率／召回率ReceiverOperatin gCharacteristic/ROC受试者⼯作特征RectifiedLinearUnit/ReLU线性修正单元Recurr entNeuralNetwork循环神经⽹络Recursiveneuralnetwork递归神经⽹络Referencemodel参考模型Regression回归Regularization正则化Reinforcementlearning/RL强化学习Representationlearning表征学习Representertheorem表⽰定理reproducingke rnelHilbertspace/RKHS再⽣核希尔伯特空间Re-sampling重采样法Rescaling再缩放Residu alMapping残差映射ResidualNetwork残差⽹络RestrictedBoltzmannMachine/RBM受限玻尔兹曼机RestrictedIsometryProperty/RIP限定等距性Re-weighting重赋权法Robu stness稳健性/鲁棒性Rootnode根结点RuleEngine规则引擎Rulelearning规则学习LetterS Saddlepoint鞍点Samplespace样本空间Sampling采样Scorefunction评分函数Self-Driving⾃动驾驶Self-OrganizingMap／SOM⾃组织映射Semi-naiveBayesclassifiers半朴素贝叶斯分类器Semi-SupervisedLearning半监督学习semi-SupervisedSupportVec torMachine半监督⽀持向量机Sentimentanalysis情感分析Separatinghyperplane分离超平⾯SigmoidfunctionSigmoid函数Similaritymeasure相似度度量Simulatedannealing模拟退⽕Simultaneouslocalizationandmapping同步定位与地图构建SingularV alueDecomposition奇异值分解Slackvariables松弛变量Smoothing平滑Softmargin软间隔Softmarginmaximization软间隔最⼤化Softvoting软投票Sparserepresentation稀疏表征Sparsity稀疏性Specialization特化SpectralClustering谱聚类SpeechRecognition语⾳识别Splittingvariable切分变量Squashingfunction挤压函数Stability-plasticitydilemma可塑性-稳定性困境Statisticallearning统计学习Statusfeaturefunction状态特征函Stochasticgradientdescent随机梯度下降Stratifiedsampling分层采样Structuralrisk结构风险Structuralriskminimization/SRM结构风险最⼩化S ubspace⼦空间Supervisedlearning监督学习／有导师学习supportvectorexpansion⽀持向量展式SupportVectorMachine/SVM⽀持向量机Surrogatloss替代损失Surrogatefunction替代函数Symboliclearning符号学习Symbolism符号主义Synset同义词集LetterTT-Di stributionStochasticNeighbourEmbedding/t-SNET–分布随机近邻嵌⼊Tensor张量TensorProcessingUnits/TPU张量处理单元Theleastsquaremethod最⼩⼆乘法Th reshold阈值Thresholdlogicunit阈值逻辑单元Threshold-moving阈值移动TimeStep时间步骤Tokenization标记化Trainingerror训练误差Traininginstance训练⽰例／训练例Tran sductivelearning直推学习Transferlearning迁移学习Treebank树库Tria-by-error试错法Truenegative真负类Truepositive真正类TruePositiveRate/TPR真正例率TuringMachine图灵机Twice-learning⼆次学习LetterUUnderfitting⽋拟合／⽋配Undersampling⽋采样Understandability可理解性Unequalcost⾮均等代价Unit-stepfunction单位阶跃函数Univariatedecisiontree单变量决策树Unsupervisedlearning⽆监督学习／⽆导师学习Unsupervisedlayer-wisetraining⽆监督逐层训练Upsampling上采样LetterVVanishingGradientProblem梯度消失问题Variationalinference变分推断VCTheoryVC维理论Versionspace版本空间Viterbialgorithm维特⽐算法VonNeumannarchitecture冯·诺伊曼架构LetterWWassersteinGAN/WGANWasserstein⽣成对抗⽹络Weaklearner弱学习器Weight权重Weightsharing权共享Weightedvoting加权投票法Within-classscattermatrix类内散度矩阵Wordembedding词嵌⼊Wordsensedisambiguation词义消歧LetterZZero-datalearning零数据学习Zero-shotlearning零次学习。

IPCameraUserManual(网络摄像头使用说明书-英文版)(精)

Vilar IP Camera VS-IPC1002 User’s ManualIndex1INTRODUCTION.............................................................................- 1 -1.1W ELCOME TO THE V ILAR IP C AMERA (11.2P ACKAGE C ONTENTS (11.3I DENTIFY VS-IPC1002 (21.3.1VS-IPC1002Views....................................................................- 2 -1.3.2Indication and Operation..........................................................- 4 -2FUNCTIONS AND FEATURES........................................................- 10 -2.1B ASIC F UNCTIONS (102.2A DVANCED F EATURES (103SYSTEM REQUIREMENT...............................................................- 11 -4SETUP PROCEDURE......................................................................- 12 -4.1VS-IPC1002P OWER &N ETWORK C ONNECTION (124.2R OUTER/S WITCH/H UB/X DSL M ODEM C ONNECTION (134.3U SE IPC AM S EARCH T OOL TO SETUP VS-IPC1002 (144.4V IEW V IDEO ON W EB B ROWSER (164.5S ETUP VS-IPC1002 ON W EB (224.6M OUNTING THE VS-IPC1002 (225SYSTEM CONFIGURATION...........................................................- 24 - 5.1S YSTEM STATUS (245.2U SER M ANAGEMENT (255.3N ETWORK (265.4D ATE AND T IME (275.5V IDEO (275.6JPEG E NCRYPTION (285.7E-MAIL (295.8FTP (305.9S ENSORS AND M OTION D ETECTION (315.10S CHEDULER T RIGGER (315.11S YSTEM M AINTENANCE (325.12S YSTEM L OG (325.13G UEST Z ONE (336VISIT VS-IPC1002 OVER INTERNET............................................- 34 - 6.1WAN IP A DDRESS (346.2N ETWORK A DDRESS T RANSLATION (NAT (356.3P ORT F ORWARDING (356.4D EFAULT G ATEWAY (366.5A CCESSING M ULTIPLE C AMERAS ON THE I NTERNET (366.6D YNAMIC D OMAIN N AME S ERVICE (DDNS (376.7C ONFIGURATION E XAMPLE (387TECHNICAL PARAMETERS............................................................- 40 -Figures and Tables IndexFigure 1 VS-IPC1002 View.........................................................- 2 - Figure 2 VS-IPC1002 Front View...................................................- 2 - Figure 3 VS-IPC1002 Back View....................................................- 3 - Figure 4 Front View Indication and Operation.................................- 4 - Figure 5 LCD Indications..............................................................- 4 - Figure 6 IP Address/Network Mask/Gateway...................................- 5 - Figure 7 Back View Indication.......................................................- 7 - Figure 8 Input & Output defines....................................................- 7 - Figure 9 Input & Output Pins Connection........................................- 8 - Figure 10 Insert a CF Card...........................................................- 9 - Figure 11 Connecting the Ethernet wire.......................................- 12 - Figure 12 connecting the power supply........................................- 12 - Figure 13 LAN connection..........................................................- 13 - Figure 14 VS-IPC1002 Search Tool..............................................- 14 - Figure 15 Modify Vi lar IP camera’s IP Address...............................- 15 - Figure 16 Input Administrator’s Username and Password................- 15 - Figure 17 VS-IPC1002 Home Page..............................................- 16 - Figure 18 Login Message box.....................................................- 17 - Figure 19 IE SecurityWarning....................................................- 17 - Figure 20 Security setting for ActiveX Controls..............................- 18 - Figure 21 Set VS-IPC1002 as a trusted site..................................- 19 - Figure 22 Video webpage...........................................................- 20 - Figure 23 History Images View...................................................- 21 - Figure 24 The right-click menu of ActiveX Control.........................- 21 - Figure 25 The bottom menu of ActiveX Control...........................- 22 - Figure 26 System Status View....................................................- 24 - Figure 27 User Management View...............................................- 25 - Figure 28 Network Setup View....................................................- 26 - Figure 29Date and Time Setup View............................................- 27 - Figure 30 Video Setup View.......................................................- 27 - Figure 31JPEG Encryption Setup View..........................................- 28 - Figure32 Require Password Input in Client Web Browser.................- 28 - Figure 33 Input Password in Web Browser (ActiveX......................- 29 - Figure 34 Input Password in Web Browser (Java........................- 29 - Figure35 E-mail Setup View.......................................................- 29 - Figure 36 FTP Setup View..........................................................- 30 - Figure 38 Scheduler Trigger Setup View.......................................- 31 - Figure 39 System Maintenance View..........................................- 32 - Figure 40 System Log View........................................................- 32 - Figure 41 “Guest Zone” View......................................................- 33 - Figure 42 Vilar IP camera’s Application Environment......................- 34 - Figure 43 Typical Network Environment.......................................- 38 -1 Introduction1.1Welcome to the Vilar IP CameraThe Vilar IP Camera combines a high quality digital video camera with network connectivity and a powerful web server to bring clear video to your desktop from anywhere on your local network or over the Internet.1.2Package ContentsNow the digital cameras are used more often in many public areas such as super markets, schools, factories and so on. Especially on some special areas such as banks and traffic cross road, its powerful image management can help you monitor those areas better.1.3Identify VS-IPC10021.3.1VS-IPC1002ViewsFigure 2 VS-IPC1002 Front View1.3.2Indication and OperationFigure 5 LCD IndicationsLCD circulates display IP Address/Network Mask/Gateway, it shown as Figure 6.System in configuration status. E.g. Upgrading firmware.Network mode indications:Icon MeaningStatic IP Use static (manually fixed IP mode.DHCP IP Address is dynamic assigned byDHCP Server.PPPoE Vilar IP Camera’s internal PPPoE dialfunction enabled.(Used for xDSLThere is a “user visiting” yellow LED on the panel. IEEuser visiting” icon of LCDFigure 8 Input & Output definesOutputA B Input Common Input 1 2Input Pins: The input pins can be used for 2-way external sensor input. For example, you may connect a Person Infrared Sensor (PIR to it for motion detection. When external sensor triggered, VS-IPC1002 can be programmed to send an email with picture or control the internal relay output.Connecting two sensors which send open and close signals to IO input pins. Pin3 and Pin4 connect two input lines of sensor 1 respectively. Pin4 and Pin5 connect two input lines of sensor 2 respectively.Figure 9 Input & Output Pins ConnectionExternal Power Socket:Connect to a 5V AC-DC adapter.CAUTION: Do not use any non-approved power adapter otherthan the ones which is accessory. This is to prevent anydamage of VS-IPC1002.RJ-45 Ethernet Socket: Connects your VS-IPC1002 to LAN.CF Card Socket: As image storage CF Card could save the sensor triggerimage on the real time or discontinuous time. Its maximum capacity is 2GByte. You have to format it as FAT16/FAT32 before use it. Both type1 and type2 CF card can be supported by this socket.2 Functions and Features2.1Basic FunctionsThe basic function of VS-IPC1002 is transmitting remote video and audio on the IP network. The high quality video image can be transmitted with 30fps speed on theLAN/WAN by using MJPEG hardware compression technology.The VS-IPC1002 is basic on the TCP/IP standard. There is a WEB server inside which could support Internet Explore. Because of that the management and maintenance of your device become more simply by using network to achieve the remote configuration, start-up and upgrade firmware.You can use this VS-IPC1002 to monitor some special places such as your home and your office. Also controlling the VS-IPC1002 and managing image are simple by clicking the website through the network.2.2Advanced FeaturesüAdvanced Image EncryptionBesides standard user authentication, there is a powerful 128-bit AES encryption can be used to ensure the image transmission safe.üDigital Video Recording and TransportationVS-IPC1002 can save the image in CF Card. sending the image to your mailbox automatic when the VS-IPC1002 is triggered.üMotion DetectionYour may use the internal Motion Detection function or external PIR sensor to trigger images recording and transportation.üAlarm sensor input/outputThe detection sensor sends an alarm and records it by itself when there is a fire or accident. A message as an email is send to you by this sensor. (Theinput/output discreteness can be chosenüDDNS supportUsing the VS-IPC1002 in the condition which including ADSL and IP change often is more convenient, because VS-IPC1002 provides dynamic DNS function.3 System RequirementüLAN: 10Base-T Ethernet / 100BaseTX Fast EthernetüWeb Browser can support ActiveX ,such as Internet Explorer 5.0 or higherüWeb Browser can support Java Applet, such as Firefox 1.5üPC – Intel Pentium III or equivalent, 1GHz or aboveü128MB RAMü800x600 resolution with 16-bit color or above4 Setup ProcedureBefore use VS-IPC1002, please setup according to the following procedures.4.1VS-IPC1002 Power & Network ConnectionStep1: Connect the network cable to the RJ45 network connections portFigure 11 Connecting the Ethernet wireStep2: Connect the power adapter to the VS-IPC1002 power socket and then insert the plug into an available power outlet.Figure 12 connecting the power supply4.2is The current IP address of VS-IPC1002, Network Mask and Gateway will be shown on the LCD panel after 1minute.VS-IPC1002 is available for visiting now. There are two methods for visiting its homepage:1. Run Vilar IP camera management tool “VilarWizard_CN.exe ” in theCD. This software will search for all VS-IPC1002 in your LAN. Select one and then click [visit] to continue.2. Run an Internet Explorer , and input the IP address as shown on the LCDto IE ’s address bar , for example: http://192.168.0.234.CAUTION: Do not use any non-approved power adapter other than the ones which are accessory. This is to prevent any damage of VS-IPC1002.In different country or region, the power supply might be different (110V/220,50Hz/60Hz, please make sure itcorrespond to the tag marked on thepower adapter.4.3 Use Vilar IP camera mangement tool to setupVS-IPC1002Insert the incidental CD into the CD-ROM drive. After run the Vilar IP camera management tool “VilarWizard_CN.exe ”, the interface as follow will pup up.Figure 14 VS-IPC1002 Search ToolThis tool shows all Vilar IP Cameras found on your LAN with its Serial Number/IP Address/Firmware Version. If your Vilar IP camera ’s IP address is not as the same segment of your PC (defined by IP Address and Network Mask, you may not be able to visit your Vilar IP camera. For example, Your PC ’s IP address is 192.168.100.33, network mask is 255.255.255.0, then your PC can visit the IP address from 192.168.100.1 to 192.168.100.255 only, If your Vilar IP camera ’s IP Address is not within this range, you cannot access it. Therefore you can click [Setup IP] button to change Vilar IP camera ’s IP address and adjust it adapting your PC setting.Click [Auto Set], let IPCamSearch tool find an available IP Address for you. Note: VS-IPC1002 by default use fixed (static IP address setting. The default IP addressis :192.168.0.234, Network Mask is255.255.255.0, Gateway is 192.168.0.1Figure 15 Modify Vilar IP camera’s IP AddressClick [OK], and then input administrator’s username and password to continue.Figure 16 Input Administrator’s Username and PasswordInput the correct username and password, and click [OK], then you can see a message box indicating Vilar IP camera’s IP Address has changed(VS-IPC1002 is in static IP mode now.Then you may click [Visit IPCam] to run an Internet Explorer, You can do more configuration by click [System Setup] on homepage of VS-IPC1002.4.4 View the video of VS-IPC1002 on Web Browser You may visit Vilar IP camera ’s homepage by IE or other compatible web browsers.Figure 17 VS-IPC1002 Home PageClick “User Visit ” to view video. You will see a message box which requires your login as shown below.Note: If you don ’t have Vilar IP camera management tool at hand, you may change your PC ’s IP Address to the same segment, according to the IP shown on Vilar IPcamera ’s front LCD. Then you can input Vilar IP camera ’s IP Address into IE ’s address bar to access.Figure 18 Login Message boxInput correct Username and password, then you can view the video.The system will prompt you install the ActiveX control when you use it first time.The follow dialog box will be indicated after you setting the security option of Internet Explorer correctly.Figure 19 IE Security WarningClick [Install] to continue. If you cannot see the message above, you must modify IE’s security configuration.You can follow this procedure to setup IE security configuration:1. Select [Internet Options] in [Tools] menu of IE;2. Switch to [Security] option card;3. Select [Custom Level];4. Setup as the following;a Init and Run unmarked as safety ActiveX controls: Select[Alert];b downloading unsigned ActiveX controls: Select [Alert];c Run ActiveX controls and plug-in: Select [Enable];Figure 20 Security setting for ActiveX Controls5. Click [OK] to save it.In addition the IPCam also can be a “Trusted Sites ”, the setting process as foll ow:1. Select [Internet Options] in [Tools] menu of IE;2. Switch to [Security] option card;Note: You can not download the ActiveX Control without authorization until setup Internet Explorer security configuration properly.3.Select [Trusted Sites];4.Uncheck “√“ before “……https:(S”;5.Input Vilar IP camera’s IP address or URL, for example,http://192.168.0.250 or ;6.Click [Add], [OK] to save.Figure 22 Video webpageThere is a pan/tilt on the top-left of the website. You can click it to move the camera Up/Down/Left/Right; or choosing the right-left cruise, up-down cruise and centered.On the left, you can also select the Resolution, Quality, Brightness, Contrast and Zoom.Resolution can be 640x480, 320x240, and 160x120. The higher resolution, the higher clarity, while requiring more bandwidth.Quality can be “High”, “Standard”or “Low”. “High”consumes largest bandwidth, thus the frame per second will down.If you feel the frame per second (fps is too slow, and want to increase it, you can select “Low” quality and lower resolution. If you hope to see clearer image, you may choose “High” quality and higher resolution.Brightness and Contrast can be changed according to different environment. “+” means add, “-” means reduce. “STD” means a standard (middle value.Zoom will show the video in a scale of half or double. It won’t affect the transport fps or bandwidth.Click [Snapshot] will pop up a new page to snap a static JPEG image, you mayclick right key of mous e and select “save as…” to store it to your computer. Click [History], will pop up a History View Page (You must have inserted CF Card first.Figure 23 History Images ViewUnder the ActiveX Control mode you can save the video on the local hard disk. Left –click the image display area of ActiveX Control, then select the corresponding function by right-click with your mouse.Figure 1 The right-click menu of ActiveX ControlYou can choose the function what you need from option at the bottom of the ActiveX Control as well.Figure 2 The bottom menu of ActiveX ControlThere are two kinds of video format such as IPEG and MPEG4. The video file size as JPEG format is bigger than MPEG4 format.VS-IPC1002 can be installed on the vertical wall by using mounting pedestal. Choosing the observed areas becomes more convenient by adjusting the VS-IPC1002 support platform at any point of view.Step 1. Find a suitable location to mount the camera.Step 2. Using the mounting bracket as a guide, mark the location of the two mounting holes.Step 3. Drill a “¼” hole for each screw.Step 4. Use a hammer to tap the two plastic anchors into the holes.Step 5. Use the two screws to fasten the bracket to the wall.Step 6. Place the camera on the mounting bracket platform and rotate the camera to be facing in the desired direction.Step 7. Secure the camera to the mounting bracket using the thumbscrew located on the bottom of the platform.Step 8. Loosen the tilt adjust thumbscrew and tilt the camera toward the area to be observed.5 System Configuration5.1System statusThis page shows status of the system for diagnose.Figure 26 System Status View5.2User Management““““”Allow Anybody Visit”: VS-IPC1002 provide a Guest Zone, if you checkedthis, any temporally visitors may enter Guest Zone to see the video without enter any username/password. If you unchecked this (default, the visitors have to enter at least a “Guest” permission username/password to visit the “Guest Zone”. At any time, the “User Zone”only allows “User”& “Administrator” permission to visit.”Vilar Backbone”Service Setup: This service as a connection of central server is useful for customer. You can choose start “Vilar Backbone” function and enter the correct user name, password, IP address of server and port information. (Vilar Backbone service depends on the Vlilar Camera addition service provided by network carrier. Please connect your camera dealer to make sure the availability of this service in your area and the relative charge of this service.5.3NetworkFigure 28 Network Setup View5.4Date and TimeFigure 29Date and Time Setup View 5.5VideoFigure 30 Video Setup View5.6JPEG EncryptionFigure 31JPEG Encryption Setup ViewFigure32 Require Password Input in Client Web BrowserFigure 33 Input Password in Web Browser (ActiveXFigure 34 Input Password in Web Browser (Java 5.7E-mailFigure35 E-mail Setup ViewThis section sets up the necessary Email server information. The administrator will have to enter a valid Account Name and Password to the Email server. This information is necessary to allow email notification features.“SMTP Server”: The administrator will have to enter the Email server address here.“Sender’s Email” This will determines Vilar IP camera’s Email address.“Email Requires Authentication”: If checked, the administrator will have to provide the account name and password in order to access the Email server.“E-mail Sender Username”: Enter the account name or login name to the Email server.“E-mail Sender Password”: Enter the password for the above account name.5.8FTPFigure 36 FTP Setup View5.9Sensors and Motion DetectionFigure 37 Sensors and Motion Detection Setup View 5.10Scheduler Trigger Figure 38 Scheduler Trigger Setup View5.11System MaintenanceFigure 39 System Maintenance View 5.12System LogFigure 40 System Log View5.13Guest ZoneFigure 41 “Guest Zone” View6 Visit VS-IPC1002 over INTERNETThe common environment for VS-IPC1002 using as follow:1.In Local Area Network (LAN only.2.Direct connect to INTERNET via xDSL (PPPoE Modem.3.Share one INTERNET connection with other computer, and connect toINTERNET via a gateway or router.Figure 42 Vilar IP camera’s Ap plication EnvironmentIf your LAN is connected to the Internet through a high speed (broadband Internet connection, you can access your cameras by web browser from anywhere on the Internet. To do this you need to:1.Know your WAN (Internet IP address. This is the IP address that yourInternet Service Provider gives you to access the Internet. It may be static (always the same or dynamic (can change from time to time.2.Make sure the router or gateway can visit the VS-IPC1002 through theport 80.3.Make sure your camera’s default gateway is set as your LAN (local IPaddress of your router/gateway.6.1WAN IP AddressThe WAN IP address is necessary when you want connect your home or business network to the internet. The WAN IP address is different from the LANIP address. It can be seeing by outside network, and it is supplied by Internet Service Provider to grant you access the internet.Your WAN IP address is stored by your gateway router which uses it to connect the Internet. All the devices on your network connect to the Internet via your gateway router. You can find your current WAN IP address by checking your router’s status page. Alsothere are various websites such as will help you find your current IP address.The term gateway is used generically to mean the device that connects a local Most a.6.2have6.3All the TCP/IP (internet networks are using software port to connect with each other. The port can be considered as channels of television. Default all the websites are through the channel 80 (port, the websites and the images can be sent via the port 80 to yourbrowser by VS-IPC1002. Therefore this channel (port can received the visiting application without the encumbrance from your router/firewall. You can visit VS-IPC1002 from the external network and those two ports have to transmitting or redirecting on the LAN IP address port by your gateway router. Thus the setting software of your router has to possessing transmission or redirecting function.Before sett ing up port forwarding, it ’s best to configure your VS-IPC1002 to use a static LAN IP since your port forwarding setup will need to be updated if the camera ’s LAN IP addresses changes.6.4 Default Gatewaycorrect request to correspond camera. All the websites requests will be sent to port 80 by browser if the default setting does not change. However the port 80 transmit therequest to one LAN IP address only, therefore all the websites requests on the port 80 will send to that address.The solution of this problem is to set up the router, assign a different port number to each camera. For example, you may set up your second camera to use port 81. When you want to access this camera, you would tell your browser to use port 81, instead of port 80. In your router ’s port forwarding setup, you would need toNote: Forwarding ports to your camera does not pose any additional security risk to your LAN.forward port 81 to the LAN IP address of the second camera. Web page requests arriving at port 81 wi ll automatically be directed to the second camera’s address.To instruct your browser to use a different port, other than 80, to access a web page, you would add the port number at the end of the IP address or URL, separated by a colon. For example, to access a camera on port 81 if your WAN IP address is 210.82.13.21, you would enter http:// 210.82.13.21:81 into your browser’s address bar. You can do the same thing with a URL such as :81.The steps to set up remote access are as follows:The solution to the dynamic IP address problem comes in the form of a dynamic DNS service.The Internet uses DNS servers to lookup domain names and translates them into IP addresses. Domain names, such as , are easy to remember as aliases of IP addresses. A dynamic DNS service is unique because it provides a means of updating your IP address so that your listing will remain current when your IP address changes. There are several excellent DDNS services available on the Internet and best of all most are free to use. Two such services you can use are and . You’llneed to register with the service and set up the domain name of your choice to begin using it. Please refer to the home page of the service for detailed instructions.A DDNS service works by uploading your WAN IP address to its servers periodically. Your gateway-router may support DDNS directly, in which case you can enter your DDNS account information into your router and it will update the DDNSser vers automatically when your IP address changes. Please consult your router’s documentation for more information. If your router does not support DDNS, you can setup the Vilar IP camera’s DDNS client.Figure 43 Typical Network EnvironmentsNow, every LAN devices connect to INTERNET via NAT function provided by IP Sharing Device. However, from the point of remote PC’s view, remote PC see only an IP Sharing Device, it doesn’t know how many PCs existed inside privacy LAN. This IP Sharing Device is also acted as a firewall.Thus, we have changed the setting of IP Sharing Device; let public PC has theopportunity to access LAN devices, e.g. VS-IPC1002.We can achieve this goal by enable Reversal NAT (RNAT function of IP Sharing Device.1.“Virtual Server”: Many routers have “Virtual Server” support. You mustforward the WAN 80 TCP port to LAN Vilar IP camera’s IP and Port. (If you visit 210.82.13.21’s 80 port outside, you will be forward to LAN192.168.0.2’s 80 port.2.Another method is the “DMZ Host”. If enabled to use a LAN device as theDMZ host, the outside PC will be able visit this LAN device directly, as ifanin7 Technical ParametersOtherCPU 32bit ARM@66MHz frequency. SDRAM 16MByte FLASH 4MByte。

STATA软件的xtnbreg命令帮助文档说明书

Title xtnbreg postestimation —Postestimation tools for xtnbregDescriptionThe following postestimation commands are available for xtnbreg :commanddescription ∗estatAIC ,BIC ,VCE ,and estimation sample summary estimatescataloging estimation results hausmanHausman’s speciﬁcation test lincompoint estimates,standard errors,testing,and inference for linear combinations of coefﬁcients lrtestlikelihood-ratio test marginsmarginal means,predictive margins,marginal effects,and average marginal effects nlcompoint estimates,standard errors,testing,and inference for nonlinear combinations of coefﬁcients predictpredictions,residuals,inﬂuence statistics,and other diagnostic measures predictnlpoint estimates,standard errors,testing,and inference for generalized predictions testWald tests of simple and composite linear hypotheses testnlWald tests of nonlinear hypotheses ∗estat ic is not appropriate after xtnbreg,pa .See the corresponding entries in the Base Reference Manual for details.Syntax for predictRandom-effects (RE)and conditional ﬁxed-effects (FE)overdispersion models predict type newvar if in ,RE/FE statistic nooffsetPopulation-averaged (PA)model predict type newvar if in ,PA statistic nooffsetRE/FE statistic descriptionMainxblinear prediction;the default stdpstandard error of the linear prediction nu0predicted number of events;assumes ﬁxed or random effect is zero iru0predicted incidence rate;assumes ﬁxed or random effect is zero pr0(n )unconditional probability Pr(y j =n )assuming the random effect is zero;only allowed after xtnbreg,re pr0(a ,b )unconditional probability Pr(a ≤y j ≤b )assuming the random effect is zero;only allowed after xtnbreg,re12xtnbreg postestimation—Postestimation tools for xtnbregPA statistic descriptionMainmu predicted number of events;considers the offset();the defaultrate predicted number of eventsxb linear predictionstdp standard error of the linear predictionscoreﬁrst derivative of the log likelihood with respect to x jβThese statistics are available both in and out of sample;type predict...if e(sample)...if wanted only for the estimation sample.MenuStatistics>Postestimation>Predictions,residuals,etc.Options for predict££Main xb calculates the linear prediction.This is the default for the random-effects andﬁxed-effects models. mu and rate both calculate the predicted number of events.mu takes into account the offset(),and rate ignores those adjustments.mu and rate are equivalent if you did not specify offset().mu is the default for the population-averaged model.stdp calculates the standard error of the linear prediction.nu0calculates the predicted number of events,assuming a zero random orﬁxed effect.iru0calculates the predicted incidence rate,assuming a zero random orﬁxed effect.pr0(n)calculates the unconditional probability Pr(y j=n)assuming the random effect is zero, where n is a nonnegative integer that may be speciﬁed as a number or a variable(only allowed after xtnbreg,re).pr0(a,b)calculates the unconditional probability Pr(a≤y j≤b)assuming the random effect is zero,where a and b are nonnegative integers that may be speciﬁed as numbers or variables(only allowed after xtnbreg,re);b missing(b≥.)means+∞;pr0(20,.)calculates Pr(y j≥20);pr0(20,b)calculates Pr(y j≥20)in observations for which b≥.and calculatesPr(20≤y j≤b)elsewhere.pr0(.,b)produces a syntax error.A missing value in an observation of the variable a causes a missing value in that observation for pr0(a,b).score calculates the equation-level score,u j=∂ln L j(x jβ)/∂(x jβ).nooffset is relevant only if you speciﬁed offset(varname)for xtnbreg.It modiﬁes the calculations made by predict so that they ignore the offset variable;the linear prediction is treated as x itβrather than x itβ+offset it.xtnbreg postestimation—Postestimation tools for xtnbreg3Methods and formulasAll postestimation commands listed above are implemented as ado-ﬁles.The probabilities calculated using the pr0(n)option are the unconditional probability Pr(y i=n) for a RE model assuming the random effect is zero.These are calculated usingPr(0|x i)=ωi+(1−ωi)p2(0|x i)Pr(n|x i)=(1−ωi)p2(n|x i)for n=1,2,...whereωi is the probability of obtaining an observation from the degenerate distribution whose mass is concentrated at zero,and p2(n|x i)is the probability of y i=n from the nondegenerate,negative binomial,RE model.ωi can be obtained from the pr0()option.See Cameron and Trivedi(1998,sec.4.7)for further details.ReferenceCameron,A.C.,and P.K.Trivedi.1998.Regression Analysis of Count Data.Cambridge:Cambridge University Press.Also see[XT]xtnbreg—Fixed-effects,random-effects,&population-averaged negative binomial models [U]20Estimation and postestimation commands。

《计算电磁学》--2010讲义

《计算电磁学》讲义
赖生建（内部资料）
物理电子学院二零一零年一月印刷
1
1、前言
一个多世纪以来，由电磁学发展起来的现代电子技术已应用在电力工程、电子工程、通信工程、计算机技术等多学科领域。电磁理论已广泛应用于国防、工业、农业、医疗、卫生等领域，并深人到人们的日常生活中。今天，电磁场问题的研究及其成果的广泛运用，已成为人类社会现代化的标志之一。
电磁场理论早期主要应用在军事领域，其发展和无线电通信、雷达的发展是分不开的。现在，电磁场理论的应用已经遍及地学、生命科学和医学、材料科学和信息科学等几乎所有的科学技术领域。计算电磁场研究的内容涉及面很广，与电磁场要解决的是实际电磁场工程中越来越复杂的建模与仿真、优化设计等问题；而电磁场工程也为之提供实验结果，以验证其计算结果的正确性。对电磁场理论而言，计算电磁场可以为其研究提供进行复杂的数值及解析运算的方法、手段和计算结果；而电磁场理论则为计算电磁场问题提供了电磁规律、数学方程，进而验证其计算结果。计算电磁场对电磁场理论发展的影响决不仅仅是提供一个计算工具而已，而是使整个电磁场理论发生了革命性的变化。毫不夸张地说，近二三十年来，电磁场理论的发展，无一不是与计算电磁场的发展相联系的。目前，计算电磁场已成为对复杂体系的电磁规律、电磁性质进行研究的重要手段，为电磁场理论的深人研究开辟了新的途径，并极大地推动了电磁场工程的发展。
在一个电磁系统中，电场和磁场的计算对于完成该系统的有效设计是极端重要的。为了分析电磁场，我们从所涉及的数学公式人手。依据电磁系统的特性，拉普拉斯方程和泊松方程只能适合于描述静态和准静态（低频）运行条件下的情况。但是，在高频应用中，则必须在时域或频域中求解波动方程，以做到准确地预测电场和磁场，在任何情况下，满足边界条件的一个或多个偏微分方程的解，因此，计算电磁系统内部和周围的电场和磁场都是必要的。

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xkБайду номын сангаасU) = #(u) + Yk,
u = 1, 2,
where {Yk} is a zero-mean stationary sequence. We consider here a more general situation where the change in mean may be due to some general change in the structure of a possibly non-linear sequence. This point is elaborated in Section 2 where several examples are given. Note also that Assumption A is stated in terms of the observable sequence {Xk}. The estimator ~ is still consistent when the magnitude of the jump A = #(1)_ #(2) depends on the sample size n and tends to zero, as n --~ e~, at a sufficiently slow rate. Suppose that the sample Xl . . . . . X, has the form - r'(") =
X~.= { X~I)
y(2) xx~.
if if
l<~k<~k*, k*<k<~n,
(1.1)
where {X(1)} E •(//(1)), {X(2)} E Z(,/.Z for some/~O) ¢ ~(2) and k* is an (2)) with fixed 0 < z* < 1.
unknownchange-point. Let k* = z*n
P{l~-~*l>/3}-< c "~-/32
n-llogn n 27-2
where the r a t e n 6/2-1 is replaced by the faster rate n -1 typical for change-point estimators in the case of independent observations, see e.g. Cs6rg6 and Horvfith (1997). Chow (1960) and Birnbaum and Marshall (1961) extended the Hfijek-R6nyi inequality to random variables which are not independent. Namely, they n( assumed that the sequences ~ 1n (X J - EXj) or ]}-'~-1 X j - EXj)[ are submartingales, which is clearly the case if the X~'s are martingale differences. Their results imply that (1.5) continues to hold under these more general assumptions. When the observations are correlated, the problem is more difficult. Beginning with a paper of Johnson and Bagshaw (1974), where the effect of serial correlation in sequential CUSUM procedure was investigated,
* Corresponding author: On leave from Vilnius University and Institute of Mathematics and Informatics, Lithuania. i Research partially supported by an EPSRC grant GR/L/78222 at the University of Liverpool. 2 Partially supported by a NATO grant CRG 960503. 0167-7152/98/$ - see front matter (~) 1998 Elsevier Science B.V. All fights reserved. PII: S01 6 7 - 7 1 5 2 ( 9 8 ) 0 0 1 4 5 - X
Uk_(k(n-k))l-r(~-~Xj
n
j=l
n - k
1~-~
j=k+l
Xj
)
(1.3)
with some 0 ~<7 < 1. In applications, considering the whole range 0 ~<? < 1 offers the advantage of being able to apply many estimators to a sample under study. Our results are valid under the following Assumption A. The observations {Xk, 1 <<.k<<.n} defined by (1.1) satisfy
STATISTICS& PROBABILITY LETTERS
ELSEVIER
Statistics & Probability Letters 40 (1998) 385-393
Change-point in the mean of dependent observations 1
Piotr Kokoszka 2, Remigijus Leipus*
P. Kokoszka, R. Leipus / Statistics & Probability Letters 40 (1998) 385-393
387
a number of authors studied the change-point problem for dependent observations, see for instance, Horv~tth (1997), Antoch et al. (1997), Horvfith and Kokoszka (1997) and references therein. Focusing on H~ijek-R6nyi inequalities, we recall a result of Bai (1994) who showed that for the linear sequence
O~
Yk = ~
j=0
ajek_j
(1.6)
satisfying
ZJlajl< ,
j=O
O(3
(1.7)
where the ek's are iid zero-mean random variables with finite variance the following Hfijek-R6nyi-type inequality holds:
386
P. Kokoszka, 1{. Leipus I Statistics & Probability Letters 40 (1998) 385-393
The estimator k of k* is defined as lc = min {k: ]Uk] = l.<j<nmax ~ IUJl' j where (1.2)
P
( m<~k<~n
max ek
Xi >~
~<
-~
mCZm+
i=m+l
c~
"
(1.8)
Assumption (1.7), which implies that the covariance function is absolutely summable, means that (1.8), and consequently (1.5), are valid for "short memory" sequences. Bai (1994) and other authors, e.g. Horvfith (1997), Antoch et al. (1997) and Horvgtth and Kokoszka (1997) studied model (1.1) with
and the change-point estimator k given by
c{
n6/2-l n6/2-1 logn
n 2~-2
/f 6 > 47 - 2, /f 6 = 4 7 - 2 , tf 6<47 - 2.
(1.4)
The proof is given in Section 3. If the sample X1 ..... Xn given by (1.1) consists of independent random variables, then the classical H~ijekR6nyi inequality (see Hfijek and R6nyi, 1955) and the arguments used in the proof of Theorem 1.1 lead to n l if 7< 1/2, if 7=1/2, if 7> 1/2, (1.5)