Enhanced Index Fund
银行内控管理工作思路及措施发展的建议和意见
银行内控管理工作思路及措施发展的建议和意见1.建立健全的内部控制制度是银行管理工作的重要基础。
Establishing a sound internal control system is the essential foundation of bank management.2.内控管理应该贯穿于银行的各个业务环节。
Internal control management should be integrated intoevery aspect of the bank's operations.3.制定符合监管要求的内控政策和流程，是银行内控管理工作的首要任务之一。
Developing internal control policies and procedures that comply with regulatory requirements is a top priority forbank internal control management.4.强化内部审计和风险管理工作，可以有效提升银行的内控水平。
Enhancing internal audit and risk management caneffectively enhance the bank's internal control level.5.建立内部控制框架，明确责任分工和控制权限。
Establishing an internal control framework to clarify responsibilities and control authority.6.加强内部员工的培训和教育，提高他们的风险意识和内控意识。
Strengthening internal staff training and education to enhance their risk awareness and internal control awareness.7.建立健全的信息披露和风险提示机制，及时向监管机构和投资者披露信息。
Report of Portfolio Management
Report of Portfolio Management Bass Sibei ZHENGExecutive summaryThe main idea of portfolio management is that the portfolio manager implements diversity managements on assets according to portfolio theories. The report tries to construct some data in accordance with a stock game to explain several principles and methods of portfolio.In the first part, the author introduces the mean variance optimization to construct rational portfolio. And put forward ratios of Sharpe, Treynor and Jensen to assess the portfolio constructed. The report intends to make analyses of the portfolio mentioned in it in accordance with a specific benchmark such as ratios mentioned above, to explain how to deal with a performance attribution in the later analysis with the changes of data and time. The conclusion turns out that the performance of portfolios will change over time, so remedies must be taken to change the portfolio and reach the target.Then, the author not only analyzes the risk/return performance of an efficient portfolio and an investment fund, but also put forward Brinson’s model to calculate the performance attribution – return decomposition analysis of the fund. What’s more, the report designs a bond portfolio to match the schedule liability in coursework 2 as well. The report also evaluates the bond portfolio constructed in before after period of time passed. The performances of portfolios change with the time, investors have to take actions to rebalance the bonds’ portfolio liabilities to match the liability durations. Moreover, several improved investment strategies are also introduced, such as hedging strategy, optimal strategy and market neutral strategy.ContentExecutive summary .................................................................... 错误！未定义书签。
MTI缩略词
1 ADSL abbr. Asymmetrical Digital Subscriber Line 非对称数字用户线路;2 APEC n.通用电子计算机（All Purpose Electronic Computer）亚太经贸合作组织，简称亚太经合组织（The Asia-Pacific Economic Cooperation）3 ATM abbr. Automatic Teller Machine 自动取款（出纳）机;Asynchronous Transfer Mode 异步传输模式4 BBS 电子布告栏系统（Bulletin Board System）5 CBD abbr.Central Business District 业务中心地区Cash Before Delivery 订金，交货前付现6 CD-ROM n. [计]（=Compact disc read-only memory）（信息容量极大的）光盘只读存储器7 CEO abbr. Chief Executive Officer 执行总裁;首席执行官8 CET College English Test的缩写，即大学英语(论坛)测试。
9 CFO abbr.Chief Finance Officer 首席财务官fiance fiancee10 CGO abbr.Chief Government Officer（首席沟通官）11 Corporate Identity 公司标志12 Chief Information Officer 信息主管13 CA abbr.Capital Airlines Inc 美首都航空公司；Certificate Authority 认证中心14 CPI abbr.Consumer Price Index 消费者物价指数15 CPU n. 中央处理器16 Central Processing Unit n.中央处理器17 CTO [法]联运经营人n.Chief Technology Officer；企业内技术最高负责人；首席技术官18 DDN abbr.Defense Data Service 数字数据服务；防卫数据网19 DHL 敦豪速递公司DHL Worldwide Express 即国际航空速递巨头——敦豪环球速递公司20 DOS n. 磁盘操作系统21 Disk Operating System磁盘操作系统22 DV abbr.Digital Video的缩写，即数码摄像，现又多指由个人制作的数字影像作品23 E-Book n. 电子书24 E-Learning n. 电子学习：特指通过互联网和电子邮件进行的学习和培训25 EMBA n.EMBA英文全称为Executive Master of Business Administration；直译为高级管理人员MBA.它是由芝加哥大学管理学院首创。
聚电解质的盐效应1
Rheology and Viscosity Scaling of the Polyelectrolyte Xanthan GumNicholas B.Wyatt,Matthew W.LiberatoreDepartment of Chemical Engineering,Colorado School of Mines,Golden80401,ColoradoReceived8April2009;accepted10July2009DOI10.1002/app.31093Published online19August2009in Wiley InterScience().ABSTRACT:The viscosity as a function of concentration for xanthan gum in both salt-free solution and in50m M NaCl is measured and compared with a scaling theory for polyelectrolytes.In general,the zero shear rate viscosity and the degree of shear thinning increase with polymer concentration.In addition,shear thinning was observed in the dilute regime in both solvents.In salt-free solution, four concentration regimes of viscosity scaling and three associated critical concentrations were observed(c*% 70ppm,c e%400ppm,and c D%2000ppm).In salt solu-tion,only three concentration regimes and two critical concentrations were observed(c*%200ppm and c e%800 ppm).In the presence of salt,the polymer chain structure collapses and occupies much less space resulting in higher values of the critical concentrations.The observed viscos-ity-concentration scaling is in very good agreement with theory in the semidilute unentangled and semidilute entangled regimes in both salt-free and50m M NaCl solu-tion.V C2009Wiley Periodicals,Inc.J Appl Polym Sci114:4076–4084,2009Key words:biopolymers;polyelectrolytes;rheologyINTRODUCTIONCharged polymer systems are encountered daily in nature as many biological polymers,such as DNA,are polyelectrolytes.Polyelectrolytes are used exten-sively in many industrial applications such as food additives,flocculants,drilling fluids,and dragreducers.Because polyelectrolytes are such an im-portant part of so many different systems and indus-tries,a fundamental understanding of the rheologyof polyelectrolyte solutions is critical.Xanthan gum is a high molecular weight,anionic, extracellular polysaccharide produced by the bacte-rium Xanthomonas campestris.1The primary struc-ture of xanthan consists of a b-1,4-linked glucan backbone with charged trisaccharide side chains(b-D-mannopyrannosyl-(1,4)-a-D-glucopyrannosyl-(1,2)-b-D-mannopyrannosyl-6-O-acetate)on alternating backbone residues(Fig.1).2,3Variations in process-ing procedures and conditions lead to varying degrees of acetyl substitution(of the mannose resi-dues adjacent to the backbone)and pyruvic acetal substitution(of the terminal mannose units).The variations in degrees of substitution on the side chains have been shown to affect the rheological properties of the polymer.4,5The primary industrial applications for xanthan gum are viscosity modifica-tion and stabilization in food products(i.e.,salad dressing,ice cream,yogurt)and personal care prod-ucts(i.e.,lotions,creams,body washes),drilling flu-ids for enhanced oil recovery,drug delivery,and drag reduction.3,6–12The global market for xanthan is$$500million annually and continues to grow. Xanthan solution properties have been studied extensively over the past40years.3,7,9,13–29The main topics of interest have included solution viscosity, polymer conformation,temperature effects on poly-mer conformation,and the effects of salt on both so-lution properties and chain conformation.Xanthan exhibits both anisotropic and isotropic phases in so-lution.24–27The relative amount of each phase pres-ent in solution depends on the polymer molecular weight,polymer concentration,and solution ionic strength.The highest concentration used here remains well below the biphasic regime.Further, xanthan has been shown to exhibit two different conformational states:an ordered,helical conforma-tion and a disordered conformation that can be described as a broken or imperfect helix.2,17,21The conformation assumed by the xanthan molecules is highly dependent on the ionic content of the solvent. In salt-free solution,the xanthan backbone is disor-dered and highly extended due to electrostatic repulsions between charges on the side chains.In this state,the chains are relatively stiff,but retain some degree of flexibility.When salt ions are present in solution,the ordered,helical conformation is sta-bilized.Xanthan chains in the helical conformationCorrespondence to:M.W.Liberatore(mliberat@mines. edu).Contract grant sponsor:Donors of the American Chemical Society Petroleum Research Fund.Journal of Applied Polymer Science,Vol.114,4076–4084(2009) V C2009Wiley Periodicals,Inc.are much more rigid than the disordered chains and have been shown to have a persistence length simi-lar to that of double stranded DNA.Several studies have reported values,both experi-mental and predicted,of critical concentrations of varying definitions.However,a comprehensive study of solution viscosity,critical concentrations,and the effects of added salt on both the viscosity and critical concentrations for solutions from dilute to entangled does not exist.In the current study,this void is filled by experimentally deriving values for the overlap (c*)and entanglement (c e )concentrations for isotropic solutions in both salt-free and 50m M NaCl solution.Scaling observations of the zero shear rate viscosity and characteristic relaxation time for xanthan solutions are also compared with a theory proposed by Dobrynin et al.30Polyelectrolyte solution rheology is complex because of the sensitivity of the polymer to the pres-ence of ions in solution.31–41Several theories have been proposed to explain the observed differences in properties between polyelectrolytes and neutral polymers.30,42–47According to the theory proposed by Dobrynin et al.30,43polyelectrolyte chains can be represented as a chain of electrostatic blobs.The blobs repel each other resulting in a fully extended chain of electrostatic blobs.The chain conformation within the electrostatic blob is essentially independ-ent of electrostatic interactions and depends solely on the thermodynamic interactions between uncharged polymer and solvent.The dynamics of the polymer chain within the electrostatic blobs are described as Zimm like,whereas the dynamics of the chain outside the blob are Rouse like.The poly-mer chain remains rodlike up to the correlation length (n ),the distance over which fluctuations in a system are correlated.For length scales larger than n ,the chain becomes flexible and is described by a random walk of correlation blobs,which are com-posed of rodlike assemblies of electrostatic blobs.The flexibility on length scales larger than the corre-lation length is due to the charge screening of sur-rounding chains in solution.Using this conceptual picture of polyelectrolye chain behavior,several scaling regimes for the zero shear rate viscosity (g 0)and characteristic relaxation time (s )for flexible polyelectrolytes in salt-free solu-tion were proposed.30Although scaling theories are stated to apply to flexible polyelectrolytes,the poly-mer persistence length,or other characteristics of chain stiffness do not appear within the theory.30,43,48When the polyelectrolyte concentration exceeds the overlap concentration (c*),g 0is propor-tional to the square root of concentration (g 0$c 1/2),in agreement with the phenomenological law pro-posed by Fuoss.33,49Empirically,the overlap concen-tration generally occurs at about twice the solvent viscosity (g s )in polyelectrolyte solutions.30The semidilute unentangled regime is predicted to be very wide,spanning three to four decades in poly-mer concentration (c e ¼103c*).The large span of the semidilute unentangled regime is attributed to the stronger concentration dependence on chain size (R $c À1/4as opposed to R $c À1/8for neutral poly-mers)30coupled with the need for each polymer chain to overlap n others to become entangled.For concentrations above c e ,the proportionality increases to g 0$c 3/2.For polyelectrolyte solutions,a certain concentration c D exists where the electrostatic blobs begin to overlap.Above c D ,the viscosity scaling is predicted to be the same as for uncharged polymers in good or H solvents (g 0$c 15/4or g 0$c 14/3).In the present work,scaling of zero shear rate vis-cosity of xanthan with concentration and the theory proposed by Dobrynin et al.are compared over a range of concentration from 10to 6000parts per mil-lion by weight (ppm).Further,viscosity,critical con-centrations,relaxation times,and dynamic moduli are reported for xanthan in both salt-free solution and in 50m M NaCl.MATERIALS AND METHODSMaterialsThe xanthan gum used in the current study is a commercial,food grade polymer (Keltrol T 622,Mat.#20000625)donated by CP Kelco in powder form.The xanthan has an estimated molecular weight of 2Â106Da and polydispersity index of $2.The man-ufacturer reports that the product is ‘‘clarifed,’’meaning extra steps were taken to remove residual cellular debris from the fermentation process.Solu-tions with concentrations up to 10,000ppm have been made and observed to be optically clear.The powder was used as received without further purifi-cation or modification.For comparison,a quantityofFigure 1Molecular structure of xanthan according to Jansson et al.2RHEOLOGY AND VISCOSITY SCALING 4077Journal of Applied Polymer Science DOI 10.1002/appthe xanthan used here was dialyzed exhaustively toobtain the potassium salt form.The rheology of the dialyzed xanthan agreed to within experimentalerror and errors expected from batch to batch varia-tion in xanthan products.Deionized water was obtained by passing house deionized water througha Barnstead NANOpure Diamond UV ultrapurewater system followed by a0.2-l m filter.The result-ing deionized water had a measured resistance of18.2M X cm.The reagent grade NaCl used wasobtained from Mallinckrodt Chemicals(Product #7581-12)and was used without further purification.The glassware used for mixing and storage of xan-than solutions was carefully cleaned with either ethanol or acetone(reagent grade),then rinsed withpurified deionized water to remove all traces of salt. Sample preparationXanthan solutions were prepared by dissolving the polymer powder in either deionized water(salt-freesolution,i.e.,no added salt)or50m M NaCl.Thesolutions were stirred using a magnetic stir bar for $1h,allowed to rest for$24h at room tempera-ture,and finally used for rheological testing.Severalsamples were prepared by adding NaCl to a xan-than solution to compare the resulting rheological properties to solutions prepared by adding xanthan powder to a NaCl solution.No measurable differen-ces in viscosity or dynamic moduli were observed when comparing the sample preparation methods. In all cases,measurements were made1–4days after solution preparation.In the period of1–4days after sample preparation,no measurable change in rheo-logical properties of the solutions was observed.The solutions were discarded6days after preparation as polymer degradation became evident(e.g.,signifi-cant decrease in viscosity and loss of optical clarity).RheologyAll rheological data were collected using a TA Instruments AR-G2stress controlled rheometer. Experiments were conducted using either a stainless steel cone(60-mm diameter,1degree)and plate or a concentric cylinder(Couette cell)geometry(of outer diameter30.0mm and inner diameter28.0mm)in steady or oscillatory shear.Sample evaporation was minimized by using a solvent trap in conjunction with the appropriate geometry.Temperature was controlled at25.0Æ0.1 C using a Peltier plate(cone and plate)or a Peltier jacket(Couette).Calibration with viscosity standard oils showed agreement with an error of<3%.The AR-G2rheometer has a torque range of0.01–200mNÁm,which is sufficiently sensi-tive to measure zero shear rate viscosities at very low polymer concentrations(c<10ppm).The data reported here are the averages of at least three replicate data sets and the associated errorbars represent one standard deviation unless other-wise noted.RESULTS AND DISCUSSIONSalt-free solutionXanthan solutions in the absence of salt exhibit a newtonian plateau and shear thinning behavior typi-cal of polymer solutions(Fig.2).Below20ppm,the xanthan solutions behave like newtonian solutions. Of note,shear thinning behavior was observed forxanthan concentrations in the dilute regime(20ppm <c<70ppm).Representative flow curves from each of the four concentration regimes(Fig.2)aredescribed well by the Cross model,g¼gÀg11þK_cðÞmþg1where g0is the zero shear rate viscosity,g1is the infinite shear rate viscosity,K is the characteristic time of the solution,and m is the rate index.As expected,g0increases monotonically with xanthan concentration and g1for all concentrations is near the solvent viscosity(Table I).Further,a power law of the formg¼A_c nfit to the shear thinning region shows that the degree of shear thinning(quantified by the power law index,n;Table I)increases with polyelectrolyteconcentration.Figure2Viscosity as a function of shear rate for several xanthan concentrations in salt-free solution.Solid lines are Cross model fits to the measured points.4078WYATT AND LIBERATORE Journal of Applied Polymer Science DOI10.1002/appUsing a set of30flow curves(four representative examples are shown in Fig.2),the critical concentra-tions for xanthan were determined from the depend-ence of zero shear rate viscosity on polyelectrolyte concentration.Over a range of three decades of xan-than concentration,four distinct regions of viscosity scaling show very good agreement with the theory proposed by Dobrynin et al.(Fig.3).The overlap concentration(c*%70ppm)is characterized by a sudden increase(by a factor of$5)in g0over a nar-row range in concentration($15ppm).The increase is attributed to the fact that as the number of polye-lectrolyte chains in solution increases,the space between the chains(and therefore the anionic charges on the chains)decreases.As the charges get closer to one another,the repulsive forces between the chains increase.Thus,there is an increase in the resistance of the chains when trying to move past one another leading to the observed increase in vis-cosity.Empirically,c*usually occurs at about twice the viscosity of the solvent(0.00088Pa s,in this case).However,the viscosity at c*for xanthan is $90times larger than the solvent viscosity.It is interesting to note that for dilute solutions,g0scales with concentration to a degree(g$c1.6)that is very close to the scaling observed in the semidilute entangled regime(g$c1.5).In the semidilute unentangled regime(c*<c< c e),g0increases as the square root of polyelectrolyte concentration,which is a weaker concentration de-pendence than for neutral polymers(g0$c in H sol-vent).The entire semidilute unentangled regime is well described by the empirical Fuoss law(g0$c1/2). Unlike the three to four decades in concentration that the semidilute unentangled region is predicted to span,this region is found to be relatively small for xanthan,spanning less than one decade in concentra-tion(c*%70ppm to c e%400ppm).Further agreement with theory is shown in the semidilute entangled regime,where g0was found to scale as c3/2.The dependence of viscosity on polye-lectrolyte concentration in the semidilute entangled regime is much weaker than the neutral polymer case(g$c15/4in good solvents and g$c14/3in H solvents).Also,the entanglement concentration is evidenced by a minimum in a plot of the reduced viscosity g R[where g R¼(gÀg s)/g s c]versus poly-mer concentration(not shown).The final critical concentration(c D)and associated increase in viscosity is observed at around2000 ppm.Dobrynin et al.defined c D as the concentration at which electrostatic blobs begin to overlap.A crossover in viscosity behavior is predicted to occur at c D where the behavior changes from that of charged polymers to neutral polymers in good or H solvents.For concentrations above c D,the electro-static blob concept breaks down,and the solution rheology is due mainly to the polymeric nature of the polyelectrolyte solution.30In this study,g0was observed to scale to the power of15/4above c D, which is identical to the scaling predicted for neutral polymers in good solvents.Therefore,our observa-tions confirm the crossover to neutral polymer behavior in this concentration region.Although the theory proposed by Dobrynin et al. is based on flexible polyelectrolytes,we show re-markable agreement for xanthan,which has been shown to be rather rigid.Several studies report the persistence length of xanthan to be100–150nm in salt solution.10,50–52Double-stranded DNA has a per-sistence length of$50nm in salt solution.48A recent study reports the persistence length of short-chain branched polyethylene(a flexible polymer)in solution to be$0.8nm.53Although most studies report persistence lengths for xanthan in an ionic so-lution,it is clear that xanthan retains a high degree of rigidity in salt-free solution.The role of chain flexibility in the scaling theory is unclear;however, our data suggest that scaling principles may success-fully be applied to rigid polyelectrolyte systems. Comparing the measured shear viscosity with the dynamic viscosity indicates that the well knownTABLE IFit Parameters for Cross and Power Law Models for Several Xanthan Concentrations Concentration(ppm)g0(Pa s)g1(Pa s)K(s)m n400039 5.1Â10À3410.78À0.72 1000 1.5 2.3Â10À3 5.80.73À0.61 2000.33 3.1Â10À3 4.80.78À0.58 500.01 1.6Â10À30.490.76À0.34Cox-Merz rule applies to the xanthan solutions stud-ied here for all but the lowest concentrations (Fig.4).The validity of the Cox-Merz rule observed seems to disagree with previous studies that have shown that the Cox-Merz rule does not hold for xanthan.25,54The discrepancy is likely due to the concentration of the xanthan solutions used.According to the phase diagram given by Inatomi et al.,27the solutions where the Cox-Merz rule does not apply lie in either the biphasic or anisotropic regime while all solutions in the present work lie in the isotropic regime.The dynamic moduli provide additional informa-tion on the viscoelastic nature of the xanthan solu-tions in the four concentration regimes (Fig.5).In the dilute limit [Fig.5(b)],the storage modulus (G 0)tends to zero (i.e.,newtonian fluid)as the concentra-tion decreases.As the polymer concentration is increased,a crossover in G 0and G 00is observed [Fig.5(a)].The crossover in G 0and G 00signifies the cross-over from more liquid like to more elastic behavior.The inverse of the crossover frequency is directly related to a relaxation time for the polyelectrolyte.The dependence of the relaxation time (s )on poly-mer concentration for polyelectrolytes differs greatly from neutral polymer behavior.Dobrynin et al.pre-dict that the relaxation time decreases with polymer concentration (scaling as c À1/2)for the semidilute unentangled regime,and the relaxation time in the semidilute entangled regime is predicted to be inde-pendent of polymer concentration.For neutral poly-mers,s is expected to increase with concentration for all concentrations.To further compare the experimental observations for xanthan with theoretical predictions,relaxation times were determined from the measured rheologi-cal data.Following the method of Boris et al.,55the characteristic relaxation time (s )was determinedfrom the viscosity verses shear rate data by deter-mining the intersection of the power law fit to the shear thinning regime and the least squares fit to the newtonian plateau.The reciprocal of the shear rate at which the power law fit and the least squares fit intersect gives a characteristic relaxation time.Four distinct scaling regions in the dependence of the characteristic relaxation time on the polyelectrolyte concentration in salt-free solution are observed (Fig.6).In the semidilute unentangled regime,the relaxa-tion time decreases with increasing polymer concen-tration (s $c À1/2)whereas in the semidilute entangled regime,the relaxation time is independent of polymer concentration.Therefore,very good agreement with theory was found in the range c*<c <c D .Published theories do not explain the relaxation time dependencies observed in salt-free solution in the concentration ranges below c*or above c D .For the xanthan solutions studied here,relaxation time increases with concentration as $c 3/2in thediluteFigure 5Dynamic mechanical properties (G 0filled,G 00open)as a function of frequency for (a)one concentration above c D and one concentration in the semidilute entangled regime and (b)one concentration in the semidi-lute unentangled regime and one concentration in the dilute regime in salt-free solution.4080WYATT AND LIBERATOREJournal of Applied Polymer Science DOI 10.1002/appregime,which is the expected result for a neutral polymer in the entangled regime.Further,as the polymer concentration is increased,a maximum in the relaxation time was observed at low polymer concentration (near c*)followed by a decrease into the semidilute unentangled regime.Similar behavior has been observed in other polyelectrolyte solu-tions,55,56but is not described by theory.In addition,the scaling of s in the dilute regime agrees very well with the scaling of g 0in the same concentration range (Fig.3).The similar dependence on concentra-tion for s and g 0suggests that,in the dilute limit,all rheological properties may exhibit a similar depend-ence on polymer concentration.For concentrations above c D ,the relaxation time shows a much stronger dependence on polymer con-centration (s $c 4).Above c D ,the polymer chains arecompletely entangled.As the polymer concentration is increased,the number of entanglements also increases.As the number of entanglements increases,the time required to dissipate the energy imparted to the solution also increases as the chains become less mobile due to the entanglements.Boris et al.55showed similar results for a well characterized sulfo-nated polystyrene sample.However,the scaling above c D for the sulfonated polystyrene was weaker (s $c 1.8)than for xanthan due,perhaps,to differen-ces in molecular structure,chain stiffness,or hydro-gen bonding.Salt solutionFor polyelectrolytes,the presence of salt in solution dramatically changes the structure of the polymer in solution which,in turn,changes the rheological properties of the solution.In 50m M NaCl solution,xanthan exhibits shear thinning behavior for concen-trations $80ppm (Fig.7).As in salt-free solution,the flow curves (Fig.7)are well described by the Cross model,and the degree of shear thinning (power law index,n )increases with polymer concen-tration (Table II).For concentrations below c D (deter-mined in salt-free solution),a sharp decrease in g 0(up to one order of magnitude)is observed in salt solution.The decrease in viscosity in the presence of salt is commonly observed for polyelectrolytes.The decrease in viscosity is attributed to the salt ions in solution shielding the ionic charges on the polymer chain from one another.The shielding due to the salt ions allows the polymer chain to assume a more compact structure in solution.Because the domains of the polymer chains decrease in size,the number of interactions with neighboring chains also decreases.In other words,more polymer chains are required in solution to get the same amount of inter-molecular interaction and subsequent viscosity increase.The relatively strong shear thinning observed at very low polyelectrolyte concentrations ($50ppm)in salt-free solution is no longer observed in the presence of salt (Fig.7).In salt solu-tion,xanthan concentrations below 80ppm were observed to be newtonian.Critical concentrations for xanthan in 50m M NaCl were determined from a plot of g 0versuspolymerFigure 6Dependence of relaxation time on xanthan con-centration in salt-free solution.Solid lines show scaling predicted by theory (c*<c <c D )whereas dashed lines are power law fits.Critical concentrations were determined from Figure 3.TABLE IIFit Parameters for Cross and Power Law Models for Several Xanthan Concentrations in 50m M NaClConcentration(ppm)g 0(Pa s)g 1(Pa s)K (s)mn2000 4.0 2.6Â10À3170.69À0.625000.04 1.9Â10À30.420.62À0.331000.0031.4Â10À30.300.57À0.08RHEOLOGY AND VISCOSITY SCALING 4081Journal of Applied Polymer Science DOI 10.1002/appconcentration (Fig.8).When salt is present,three concentration regimes are observed (as opposed to four in salt-free solution).For concentrations above c*,the dependence of g 0on concentration is much stronger than in salt-free solution.In the dilute re-gime,g 0scales directly with xanthan concentration (g $c ).Above c *,the scaling increases to g 0$c 2.In the semidilute entangled regime,the scaling of g 0is much stronger with concentration (g 0$c 14/3).Very good agreement with the scaling predictions for a neutral polymer in a H solvent was observed in the dilute,semidilute unentangled,and semidilute entangled concentration regimes despite the rigidity of the xanthan chains in salt solution.The measure-ments confirm the prediction that neutral polymer behavior is observed in the presence of salt.Further,in the presence of NaCl,the abrupt increase in g 0observed at c*in salt-free solution was not observed.The less dramatic transition near c*may be due to the salt ions in solution screening the Coulombic interactions that the polymer experiences in salt-free solution.An increase in both c*and c e is observed in the presence of NaCl.The overlap concentration ($200ppm)is almost three times larger than c*in salt-free solution ($70ppm).The entanglement concentra-tion ($800ppm)is twice the value of c e in salt-free solution ($400ppm).The third critical concentra-tion observed in salt-free solution (c D )is not observed in the presence of NaCl in the polymer concentration range studied here.Because the critical concentrations are dependent on interactions between polymer chains,it follows that solutions of smaller chains would exhibit higher critical concen-trations.As stated previously,the salt ions in solu-tion screen the electrostatic interactions between the ions in solution and allow the polymer chains toassume a smaller average configuration.Thus,smaller domain size of the polymer chains corre-sponds to higher critical concentrations.The scaling of the relaxation time for xanthan in the presence of salt (Fig.9)differs markedly from the scaling in salt-free solution.Theory predicts that s scales as c 1/4in the semidilute unentangled regime and as c 3/2in the semidilute entangled regime for polyelectrolytes in salt solution.Experimental meas-urements agree very well with theory in these two concentration regimes.For xanthan concentrations below 80ppm,the samples are newtonian,therefore no relaxation time can be determined (by definition,s ¼0for newtonian fluids).For concentrations above 80ppm in the dilute regime,relaxation time seems to be independent of polymer concentration (s $c 0).The apparent independence of relaxation time in the dilute regime is likely due to the relatively small number of polymer chains present in the solu-tion.Below c*,the polymer chains do not interact appreciably one with another.Therefore,the relaxa-tion time observed for the solution will be depend-ent solely on how individual chains react to the stress applied to the solution.The maximum in s observed for xanthan in salt-free solution (Fig.6)was not observed in the presence of NaCl.When the polymer concentration is increased above c*,inter-molecular interactions become important,and the result is an increase in the relaxation time (i.e.,s is no longer independent of polymer concentration).Further,the decrease in the magnitude of the relaxa-tion time in both the semidilute unentangled and semidilute entangled regimes is consistent with the fact that the rigid,helical xanthan conformation is stabilized by the presence of salt.The increaseinFigure 8Zero shear rate viscosity scaling dependence on xanthan concentration in 50m M NaCl.Solid lines show scaling predictions for neutral polymers in H solventconditions.。
13010502班口译词汇
Interpretation Expressions1. Economy1.trade deficit 贸易逆差2.CPI(consumer price index) 消费价格指数3.fixed assets investment 固定资产投资4.U.S. subprime mortgage crisis美国次贷危机5.Curb inflation制止[控制]通货膨胀6.macro control measures 宏观调控政策7.The threshold of ……的门槛8.slashing tax rebate 大幅降低退还税款9. a prudent fiscal policy and a tight monetary policy稳健的财政政策和从紧的货币政策10.adverse effects 不利影响11.individual income 个人收入12.sleet and snow disaster 雪灾13.prevent the economy from over-heating 防止经济过热14.referendum on joining the United Nation under the name of Taiwan台湾入联公投15.trade power 贸易大国16.expand domestic demands 扩大内需17.In the upper reaches of the river 在河水上游In the lower reaches of the river 在河水下游11.trade surplus 贸易顺差12.UNDP: United Nations Development Program13.Income disparity:收入差距14.Iron rice bowl:铁饭碗15.State-owned enterprise:国有企业16.Maternity leave:产假17.Economic base determines the super structure.经济基础决定上层建筑。
ergonomics7
• Identify and reduce/eliminate risk factors and ergonomic hazards • Integrate ergonomics into the culture of the organization
– Predictive factors
• Treating patients with heavy calculus (increased force) • Operating in the 10 or 12 o’clock position (increased flexion or wrist deviation) • Practicing longer than 5 years (increased exposure)
EXPANDED ERGONOMICS PROGRAM
(Optional)
• Establish an ergonomics committee
– Include workers
• Analyze the worksite
– Use inspections, surveys, records review
– Due to improperly positioned (bent) wrist(s) or wearing ill-fitting gloves
DENTAL CLINICS
• Should provide an ergonomic environment to:
– Protect the well-being of dental workers – Improve clinic efficiency – Increase patient comfort
quiz 1(2)
3.(Points: 0.5) Derivative securities are:a. potentially dangerous because they are highly leveraged.b. an effective tool to better manage business returns and risk.c. always structured as option contracts.d. both A and B are true.e. all of the above are true.In the event of the firm's bankruptcy:a. the most shareholders can lose is their original investment in the firm's stock.b. common shareholders are the first in line to receive their claims on the firm's assets.c. bondholders have claim to what is left from the liquidation of the firm's assets after paying the shareholders.d. the claims of preferred shareholders are honored before those of the common shareholders.e. A and D.Exchange Traded Funds area. Open end fundsb. Traded in both primary market and secondary market simultaneouslyc. Designed to be traded at a price close to NAV of the fundd. All the aboveWhich of the following would increase the net asset value of a mutual fund share, assuming all other things remain unchanged?a. An increase in the number of fund shares outstanding.b. An increase in the fund's accounts payable.c. A change in the fund's management.d. An increase in the value of one of the fund's stocks.The formal process of transferring legal ownership or title of the securities is calleda. Transactionb. Registrationc. Settlementd. All the aboveThe implicit cost of IPO is also known asa. Under Quotingb. Underwritingc. Underpricingd.Under SellingFor an investor with coefficient of risk aversion = 5 and utility function: U = E(R) - 0.005*A*variance; the certainty equivalent rate of an investment with expected return 15% and 20% standard deviation is:a. 4.5b. 7c. 5d. 5.5Risk averse investorsa.Never speculateb. Never gamblec. Always accept fair gamed. None of the aboveIf the standard deviation of stock A is 29, the standard deviation of stock B is 31, and the covariance between stocks A and B is 486.25, the correlation between stocks A and B is:a. 0.54b. 0.45c. 0.27d. -0.27e. 417.23Indifference curves representa. All investments with equal riskb.All investments with equal returnc. All investments with equal risk premiumd.All investments with equal utilityA reward-to-volatility ratio is useful in:a. measuring the standard deviation of returns.b. understanding how returns increase relative to risk increases.c. analysing returns on variable rate bonds.d. assessing the effects of inflation.e. none of the above.Reward to variability ratio 0.5 meansa.For each unit return investor is ready accept 0.5 unit riskb. Risk premium should be at least 0.5c. For each additional unit of risk, investor demands 0.5 unit of excess returnd. All the aboveIn the mean-standard deviation graph, the line that connects the risk-free rate and the optimal risky portfolio, P, is called :a. the Security Market Line.b. the Capital Allocation Line.c. the Indifference Curve.d. the investor's utility line.e. none of the above.You invest $100 in a risky asset with an expected rate of return of 0.12 and a standard deviation of 0.15 and a T-bill with a rate of return of 0.05.What percentages of your money must be invested in the risky asset and the risk-free asset, respectively, to form a portfolio with an expected return of 0.09?a. 85% and 15%b. 75% and 25%c. 67% and 33%d. 57% and 43%e. Cannot be determined.Long term Government bonds generally havea. High interest rateb. Interest rate riskc. High default riskd. All the aboveWhich of the following indices is (are) market value-weighted?I) The ASX200 IndexII) The Standard and Poor's 500 Stock IndexIII) The Dow Jones Industrial Averagea. I only.b. I and II only.c. I and III only.d. I, II, and III only.e. II and III only.Certificate of Deposit (CD) area. Considered more risky than Commercial Papersb. Time deposits that can be always withdrawn on demandc. highly liquid and investors can sell it to other investorsd. All the aboveSelling stocks without owning it is known asa. Margin tradingb. Derivatives tradingc. Short sellingd. Stop loss sellInvestors' always select a risky investment over a risk free investment ifa. Risk premium is positiveb. Certainty equivalent rate is less than risk free ratec. Return of the risky portfolio is greater than risk free rated. Certainty equivalent rate is greater than risk free rateIf risk free borrowing and lending is possible then Capital Allocation Line (CAL) can havea. More than one reward to variability ratiob. Different reward to variability ration at each point on the CALc.Only one reward to variability ratiod.Both A and BWhen a portfolio consists of only a risky asset and a riskless asset, increasing the fraction of the overall portfolio invested in the risky asset will:a. increase the expected return on the portfolio.b. increase the standard deviation of the portfolio.c. not change the risk-reward ratio.d. Neither A, B nor C is true.e. A, B and C are all true.Financial assets:a. directly contribute to the country's productive capacity.b. indirectly contribute to the country's productive capacity.c. contribute to the country's productive capacity both directly and indirectly.d. do not contribute to the country's productive capacity either directly or indirectly.e. are of no value to anyone.Following is an example of insider tradinga. Company employees are buying stocks based on a rumour of a mergerb. Company directors are selling their sharec. CEO sells his shares of the firm based on his private informationd. Buying stocks based on an analysts recommendationGenerally, risk aversion coefficient of a borrower is _________risk aversion coefficient of a lendera. Lower thanb. Higher thanc. Same asd. None of the aboveWhich of the following are characteristics of preferred stock?I) It pays its holder a fixed amount of income each year, at the discretion of its managers. II) It gives its holder voting power in the firm.III) Its dividends are usually cumulative.IV) Failure to pay dividends may result in bankruptcy proceedings.a. I, III, and IV only.b. I, II, and III only.c. I and III only.d. I, II, and IV only.e. I, II, III, and IV.The value of a derivative security:a. depends on the value of the related primitive security.b. can only cause increased risk.c. is unrelated to the value of the related primitive security.d. has been enhanced due the recent misuse and negative publicity regarding these instruments.e. is worthless today.Hedge fundsa. Follow high risk investment strategyb. Suitable for institutional investors & high net worth investorsc. Charges performance based feesd. All the aboveYou sell short 100 shares of Loser Co. at a market price of $45 per share. Your maximum possible loss is:a. $4,500b. unlimitedc. zerod. $9,000e. cannot tell from the information givenIndifference curves of an investor __________intersect because_____________a. Can; each investment can have multiple utility score for an investorb. Should; investments always have multiple utility scores for an investorc. Cannot; each investment can have one utility score for an investord. Cannot; each investment has different riskWhich of the following statements is (are) true?I) Risk-averse investors reject investments that are fair games.II) Risk-neutral investors judge risky investments only by the expected returns.III) Risk-averse investors judge investments only by their riskiness.IV) Risk-loving investors will not engage in fair games.a. I only.b. II only.c. I and II only.d. II and III only.e. II, III, and IV only.In the mean-standard deviation graph an indifference curve of a risk averse investor has a ________ slope.a. negativeb. zeroc. positived. north-easte. cannot be determinedA perfectly indexed default free bond。
用友UFIDA财务供应链生产(English)
Enter UFIDA World… World…
U8 Financial Accounting
U8 Financial Accounting
General Ledger
Mainly for voucher processing, accounting book processing, individual transaction fund management, project cost management and cash management. Selected Features:
Control Order Forecast Sell/Shipping Order Shipping Invoice Processing Accountant Selling Cost Account Finance Plan Cash Forecast Finance Frecast E-bank A/R GL Hasten Receipt Arrearage Profit/Deficit
Bank
Drill down inquiry from GL to detailed accounting book and even to the original bill or invoice. User-defined accounting items. Provides Rigorous withdrawal process controls . Auxiliary accounting functions. Automatically calculates debit and credit balance.
U8 Financial Accounting
Persistence Models
JDO: Persistence Manager
private static PersistenceManager createPersistenceManager() throws IOException { Properties properties = new Properties(); InputStream is=Main.class.getClassLoader().getResourceAsStream("jpox.properties"); if (is == null) { throw new FileNotFoundException("Could not find jpox.properties file that defines the JPOX persistence setup."); } properties.load(is); PersistenceManagerFactory pmfactory = JDOHelper.getPersistenceManagerFactory(properties); PersistenceManager pm = pmfactory.getPersistenceManager(); return pm;
public Fund () { }
public Fund (String name, double growthrate) { = name; this.growthrate = growthrate; } @Id @GeneratedValue public int getId () { return id; } public void setId (int id) { this.id = id; }
番茄病毒病识别和控制说明书
University of California Cooperative Extension, Yolo C ounty 70 Cottonwood Street, Woodland, CA 95695 530-666-8143 31 Jan 2013 (Volume 53-1)T OMATO IT OMATO S POTTED W ILT V IRUSV) has persisted in our area over the last several years and has sceptible varieties, the Table 1. Tomato spotted wilt virus : a visualhe value of the variety susceptibility guide (Table 1) is to provide a relative idea of the he TSWV research team that is based on ramento Valley area, it is less clear exactly what factors (e.g., surrounding vegetation) make a high-risk site. Especially in an early-planted field, if the virus didn’t come Tomato spotted wilt virus (TSW now become more widespread. The extent of damage (symptoms) in parts of some fields may exceed 20%, however, overall infection in most fields appears to be in the 1 to 2% category. The California Tomato Research Institute has continued to fund a TSWV research project over multiple years to develop an integrated pest management (IPM) strategy for thrips and TSWV. The management of spotted wilt for some is simple: plant a resistant variety. A number of varieties with TSWV resistance are available. With high demand, the 2013 supply is anticipated to be limited.Among the su range of symptom severity(susceptibility) is broad. UC Fresno Advisor Tom Turini working with UC Tulare Advisor Michelle Le Strange evaluated susceptible varieties to assess the percentage of plants infected with spotted wilt. Varieties were compared over a 6-year period from 2007 to 2012. Trials were all planted near Five Points at or around the UC Westside Research and Extension Center. Not all varieties were compared each year, but the compilation provides a rough guide to categorize those varieties repeatedly showing a tendency toward high, medium or low incidence.assessment of susceptibility Medium T susceptibility of processing tomato varieties. Growers can then make choices based upon the potential risk for thrips and TSWV in a given field.A risk index for TSWV has been developed by t factors that have been identified as playing a role in disease development, e.g., planting date, surrounding crops as hosts or bridges for the virus, proximity to weedy fallow fields and site history. At this point, fields at risk are those planted 1) near bridge crops (lettuce, radicchio and fava beans) or weedy fallow fields, 2) late in the season (and thus near old tomato fields), and3) in locations that historically have high levels of disease (hot-spot areas). If seed supply of resistant varieties is limited, growers should consider planting resistant varieties in these high-risk fields.For our Sac to Low variable High BQ 163H 2005H 8004H 2206Sun 6366BOS 602UG 19406H 1015H 8504Sun 6368NDM 5578HM 6898H 4407CXD 282H 2601H 2769AB 2AB 3H 3004H 9780Nun 672H 6397K 2770APT 410UG 15308CXD 255BQ 205HMX 7885UG 4305PX 1723eason, and this could explain how lone TSWV-infected plants into the field with infected transplants (which appears to be uncommon for commercially produced processing tomato transplants), the surrounding vegetation is likely the host source. But from all the survey and scouting work that UCD Plant Pathologist Bob Gilbertson and team did on evaluating weed hosts and crops, there were few ‘smoking guns’ identified. Radicchio, especially, and the winter cover crop fava bean were 2 crops that were identified as good bridges to extend the virus into the next season. And while there were many cases of high TSWV infection in tomato fields along a border (that pointed to the TSWV coming from adjacent fields and the surrounding area), there hardly was a common thread tying the high incidence into a neat package.Recent research suggests that thrips emerging from soil are another potential source of TSWV inoculum early in the growing s can be found in the center of fields, far removed from potential plant hosts. For sure, the levels of thrips and TSWV are low early in the season and efforts to eliminate known bridge crops and weedy fallow fields (a place that both thrips and TSWV can be amplified) will benefit both early and late planted crops in terms of reduced thrips and virus pressure. Table 1 would be enhanced if coupled with yield outcome. To provide a glimpse at yield from these tests (Table 2), yield is shown for year 2011, when TSWV infection level ranged from 0 to 53% of plants showing symptoms when rated 0 to 4 weeks before harvest. For instance, the spotted wilt resistant variety H 5508 had a near zero level of infection coupled with a high yield output of 66.5 tons/acre. However, yield from susceptible variety H 7709 with a 33% TSWV infection level also had high yield with 62.9 tons/acre. From this data set, AB 3 would not be particularly attractive knowing it is high risk (gleaned from Table 1) and relative yields were in the lower ranking group (at 48.6 tons). And based solely on Table 2 results, AB 0311, while possessing spotted wilt resistance and with ‘zero’ detectable virus symptoms, yield level was in the lowest performing group. Note: For local growers, the Fresno yield comparison table might not directly apply to your variety selection decisions- rather it is used in this example to illustrate that variety fitness in aottom Line particular field depends upon multiple factors beyond just disease resistance .Table 2. TSWV incidence and tomato yield outcome, UC Westside Research and ExtensionCenter, Five Points (Turini and Le Strange, 2011)Tomato spotted wilt virusYield (% infected plants)Variety tons/a 18-Jul 11-Aug 23-Aug1AB 0311SW 39.6 e 000a2H 5508SW 66.5a 001a3N 6394SW 49.1 bc 013a4UG 19406-71619 bc5H 340253.8 b 102121 bc6BQ 20546.5 cd 192627 bcd7Sun 6368-142429 bcd8HMX 990553.9 b 192831 cd9H 770962.9a 303033 d10H 8004-173235 d11H 978046.1 cd 123438 d12AB 348.6 c 255053 e13Sun 636642.0 de ---LSD 4.99.113.512.3% CV 7494335B : While it is likely that TSWV reduces yields and resistance is an effective anagement tool, the field performance of a variety, even under high disease pressure, depends on other factors that may not be related to TSWV resistance.mChemical control :F th resno Advisor Tom Turini has also looked at a number of insecticide programs targeting the rips vector of tomato spotted wilt. After several years of trials, he concludes that the e most effective as foliar applications:4.3 fluid oz.)In gene as a target threshold level of the insect vector as a ‘trigger’ to initia thresholds are far ore d within the field or in fields in the etative growth stage of there will be a constant wave of ‘new thrips’ coming into the field. There is bit of following materials ar Dimethoate 4EL (at 1 pint)Lannate SP (at 1 lb.)Radiant SC (at 6 fluid oz.)mbined with Mustang (at Beleaf 50 SG (at 2.8 oz.) co ral, a good IPM program h te a treatment. While this is relatively easier for insect pests, such ifficult to establish for insect-transmitted viruses where there is not a direct correlation m between insect numbers and virus incidence. The threshold would ideally be developed by quantifying a collection of infectious thrips that results in economic crop damage, but such a program of detection is difficult to develop and execute.Thus, the best insecticide strategy is to make the initial application when thrips population build-up is initially detected (with yellow sticky card traps or the predictive model indicates the rst adults have hatched) and when TSWV is just detected fi general vicinity. Growers who are not certain whether the symptoms in their fields are TSWV should have the sample tested, as other viruses can cause symptoms that mimic TSWV and these viruses are not spread by thrips. Field test kits exist for rapid confirmation of TSWV. Delaying the initiation of spraying until confirmed presence of thrips/TSWV will reduce unnecessary sprays. Once thrips and TSWV appear in the field, multiple repeat applications are likely needed depending on thrips pressure and TSWV incidence.Treat early. The seedling-stage through the flower setting stage of tomatoes is more sensitive to TSWV damage than the fruit sizing and ripening stage. Reduce the thrips population within he field to reduce disease spread especially during the sensitive veg t tomatoes.In a given year, it is likely thrips population will be high and any insecticide program will provide only partial control at best. Migration of thrips from outside of the field will likely ontinue so c good news: the adult thrips can’t acquire the virus. Thus they have to come to the field ‘dirty’ or have offspring within the tomato field for their young to feed on infected plants—thus leaving the young to spread the virus. The most effective strategy for the grower is to spray early when the thrips and virus first appears and then follow with repeated sprays during the most sensitive stages of plant growth. Spraying should cease well before early ripening begins since mature plants are less susceptible to yield loss.To reduce development of insect resistance, rotate insecticide chemistries rather than repeatedly using a singular material within the season.In over 4 years of trials, Advisor Turini has consistently found the neonicotinoid insecticide Platinum was ineffective when applied through a drip irrigation system for thrips and TSWV anagement in tomatoes. Platinum and other neon m icotinoids have activity against other insect pests, but should not be used for thrips control.Web sites seasonal thrips & TSWV reports:UCD Pathologist Neil McRoberts (working with thrips population development for several produ Bob Gilbertson) developed a model to predict ction areas including Yolo-Colusa. https:///site/cubelabsite/current-research/tomato-spotted-wilt-virus/thrips-population-projectionsChuck Rivara of the CTRI created a program to send email alerts about TSWV thrips activity. ign up for this free service at STSWV test kits: Field test kit from Ag Dia/InventoryD.asp?loc=IN&collection=ISK%2039300&attribute_Size=25https://orders.agdKit from Envirologix: /artman/publish/article_249.shtmlThe field kit from AgDia is individualized and easy to use in the field. The kit from Envirologix like a simple chemistry 1a lab set that is more suitable for use on a bench in the office. ene MiyaoFarm Advisor, Yolo, Solano & Sacramento countiessement of named products is intended, nor is Either is valuable to detect TSWV from plant tissue. Cost is about $5 for each sample tested. Minimum purchase is a package of 25.ubmitted by,SG To simplify information, when trade names of products have been used, no endor criticism implied of similar products, which are not mentioned. The University of California, in accordance with applicable Federal and State law and University policy, does not discriminate on the basis of race, color, national origin, religion, sex, disability, age, medical condition (cancer-related), ancestry, marital status, citizenship, sexual orientation, or status as a Vietnam-era veteran or special disabled veteran. The University also prohibits sexual harassment.Inquiries regarding the University's nondiscrimination policies may be directed to the Affirmative Action Director, University California, Agriculture and Natural Resources. 300 Lakeside Drive, 6th Floor, Oakland, CA 94612-3560. (510) 987-0096 of .。
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Enhanced Index Fund - EIF What Does Enhanced Index Fund - EIF Mean? A mutual fund that tracks a stock market index, but with certain modifications in place to allow for more equivalent position sizes, the exclusion of certain securities, or the use of leverage, all with the goal of beating the return of the tracking index. These types of funds are actively managed, and will often use the S&P 500 Index as the tracking index.
Investopedia explains Enhanced Index Fund - EIF Enhanced index funds trade with the "index fund" title, but to be fair, that's where the similarity usually ends. True index funds have consistently lower fees, lower turnover and passive management. Enhanced index funds, on the other hand, are actively managed to beat the return of the tracking index. This approach causes relatively higher fees and turnover than the traditional index fund. While proponents of enhanced index funds cite better total return performance as a plus for this type of fund, investors need to be aware that using leverage and active management also increases risk, at least as compared to a conventional index fund.
指数化的基本任务是追踪一个被选指数的收益，而加强指数投资追求的是连续并适当超过指数收益，同时严格控制追踪误差和低于市场表现的风险。积极基金经理的投资目标是超过指数收益，消极基金经理目标是追踪和匹配指数，而如果加强指数化投资追求超过指数，则一定采取积极的管理技术，如果紧密追踪指数，会使用指数投资的一些控制风险技术。因此以追踪误差限制等为风险控制控制手段的采用战术资产配置的积极管理的投资策略对于加强指数化是一个合适定义。
1.1收益加强投资策略概述 收益加强投资通过积极管理加强收益，通过指数化技术控制风险。但是他并不是免费的午餐，加强收益的获得来源于承受更多的风险，而控制风险的一个主要原则是采用能够获得温和的收益的策略。因此，一般来说，积极基金追求的是收益最大化，而把风险放在第二位考虑。加强性指数化投资则是平衡过度收益与风险做出最优抉择。
下面还可以定量区分三者之间的区别。首先定义：Alpha，信息比率。Alpha定义为风险调整后相对于指数的超额收益。期望收益＝ Alpha ＋Beta＊（指数收益）。对于加强型指数化可以简单表示为：Alpha ＝期望收益－指数收益或者Alpha ＝期望过量收益。这里假定Beta趋向于一。这个假定与大多数加强指数化策略的设计理论相一致，一个更加简单的方法是让ALPHA定义为一个基金经理的历史表现。Alpha测量基金经理超额收益的均值，追踪误差测量Alpha的标准偏差，并且如果我们假定过量收益服从正态分布，则均值和标准偏差可以用统计推断。最常用的推断为超额收益非零的可信性，换句话说是，如果一个基金经理获得过量收益，这个过量收益不是由于运气和偶然的概率是多少。定义为：信息比率＝ Alpha ／追踪误差。信息比率很象统计， 用来测量Alpha的统计重要性。假设我们有一个基金经理5年的Alpha和追踪误差，我们可以得到信息比率。为了有95％的置信度，一个基金经理5年记录非运气的信息比率1.25。
已经定义几个概念，现在可以用来区分不同投资策略的区别。对于唇指数化投资，其期望的Alpha为零，最成功的指数基金经理的历史追踪误差为0.2％或者更低。因此，信息比率趋向于零。而对于积极管理投资，其期望年Alpha为2％或者更高，但是美国的历史记录显示追踪误差超过4％，这样结果导致信息比率为0.5或者更低。加强型投资强调稳健收益，年期望Alpha为0.5％到2％之间，加强型投资另外一个目标是降低追踪误差，历史记录表明是0.5％－2％之间，因此得到的信息比率为0.5－2之间。另外一个问题是如果给定一个信息比率，需要多少年的记录表明Alpha非零的置信度为95％？一个统计标准是信息比率为0.5，需要置信度为95％判断年数为18年，而信息比率为1，需要置信度为95％判断年数为6.5年，而信息比率为1.25，需要置信度为95％de判断年数为5年。
当然统计的重要性不是唯一的准则，经济上的重要性也非常重要。比如一个基金经理采用复杂的积极投资策略产生10个基本点的Alpha，10个基本点的追踪误差，这个Alpha的95％的统计重要性需要6.5年，但是基金发起人可能认为10个基本点的超额收益不足以覆盖这个复杂投资过程的监管的经济成本。又比如一个积极基金经理5年产生500个基本点的超额收益，但是1500基本点的追踪误差，基金经理的投资过程容易监管和理解。因此，即使统计上并不可信，但是基金发起人仍然会采用这个基金经理的投资策略以期望带来长期高额收益。信息比率是一个有效的工具，但是选择投资方式是需要根据投资者的特征。比如，需要较低管理费和指数收益的投资者会选择纯指数化投资，而追求最大化收益，对风险有一定忍受程度的投资者会选择积极管理的投资策略，而加强型指数策略则位于二者之间。一般来说加强型指数策略的管理费用也位于二者之间，并且，加强型指数基金一般采用投资执行情况为基础的费用选择，及根据获得超过指数的部分收益收取管理费用，这说明加强管理型基金对自己采取追求稳定的Alpha和适当风险的投资策略的信心。
1.2股票市场的加强策略研究 笔者认为可以分为两类策略，一类是以股票为基础的策略，另一类是应用衍生品的策略。两种策略强调获利的来源不同，风险暴露的来源和程度不同以即控制风险的技术不同。以股票为基础的策略应用广泛多样化组合为基础适当采取某些股票选择策略以获得稳当和持续的收益。任何收益加强的策略都基于某种形式的股票选择能够增加基金的价值，尽管关于市场效率有很大争议性，强调风险控制能够提高策略应用成功的可能性和防止出现巨大的损失为加强指数基金迅速发展的主要因素。一些加强指数基金用财务模型（价格收益比，股利收益等），一些用权重模型（行业权重，规模权重，风格权重等）。
1.2.1倾斜（Tilt）策略 基本思想是首先建立一个纯指数基金，然后依赖于客户的偏好侧重某方向的投资。比如样本权重，价值和增长等风格，收益率或者行业板块为最常采用的倾斜方向。Alpha的期望来源于价值股票，增长型股票和高股利股票能够获得超过市场的收益。这里只是侧重投资，而不象积极投资那样大规模强调某个方向。 一些积极的投资策略完全可以应用到加强指数投资策略，只是在方法上更加规范，给基金经理的限制更大，比如股票选择模型，通过预先设定的模型过滤有投资价值的股票，最简单的倾斜方法是建立市盈率标准，低于此的股票加重权重，高于此的股票降低权重。但是Levy（1989）研究表明金融市场非常复杂，需要刚性的规范下多种模型联合选择，构造一个选择体系和网络才可以克服这些问题。Twark（1991）提出多模型规范化的股票选择体系来加强收益，其基本思想是通过实证分析选择一些财务比率，经济数据和股票技术特征的模型联合起来，对股票进行排序，然后在指数组合的基础上进行调整倾斜，模拟数据表明其策略获得每年超额标准500指数8％的收益率。但是模型的时效性需要考虑，比如一个成功的模型随着被广泛的采用或者假设条件发生变化而效果大大降低，所以基金公司研究部门要不断开发新的加强收益模型。风险控制为拥有指数中所有股票或多样化降低风险。随着近年来特色指数的出现，倾斜策略的使用度越来越少。
耶鲁大学研究机构的一项统计研究表明，对基金收益应用主成分分析，一个基金90％的收益来自于资产分配，也就是如何构建投资组合，其余10％来自于交易技术和个股选择。威廉·夏普教授的研究同样支持这个结论。而资产分配中最重要的是板块权重分配。市场是由大盘，中盘，小盘，价值，成长，科技，金融，重组，国际，区域等各个相互交叉的板块组成。不同的经济环境和经济政策对于每个板块收益产生不同的影响。这种影响经常是显著不同的。这些不同在于不同板块的基本面不同。如果对于经济环境和板块特性有深入的研究则可以显著的增加基金的额外收益。近来第一麦迪逊公司进行了关于板块投资的研究。他们使用美国股市1980－1996年一共17年的数据，把资金按照股票板块分成四种类型以模拟威谢5000指数，研究发现，该组合17年平均收益为15.61％， 但是如果在每个季度末有效调整组合分配加重对下季度收益最好的板块投资，则可以获得的最大年收益为30.70％，这是一个理想状态下的收益，但是从中可以看出，有效的进行板块调整对于额外收益的影响是非常重要的。市场指数已经包含了各种不同类型的板块，仅通过追踪市场指数，建立一个板块中性（随指数变化而变化）的组合可以获得与市场相匹配的收益，而通过对板块权重作出调整是收益加强基金加强收益的最符合逻辑的方法。相对于强调交易技术和个股选择，通过调整板块权重加强收益更显著，比如，选择个股遭受的损失风险要比选择板块要大， 对个股收益和价格走势的预测要比通过对宏观经济把握和市场供求判断进行的板块选择要难。通过与指数匹配获得市场收益，通过确定与指数板块权重的偏离度以明确投资纪律，通过板块选择加强收益，从理论上说，收益加强指数基金可以为投资者带来更大更安全的收益。板块选择主要问题来自于股票替代率，Barra的一项研究表明，1986－1996年标准500指数每年的股票周转率为4.4％，而一些采用板块策略改变标准500指数权重的加强基金的股票周转率为每年23％，大大增加交易成本和基金经理对板块误判的概率。为了避免此种情况，可以有下列解决方法：1、明确组合板块偏离指数的程度，2、对调整次数和周转率做硬性规定，3、调整板块中最具有本板块明显特征的个股，维持中间部分不变。