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化学专业外文文献初稿和译文稿

化学专业外文文献初稿和译文稿引言该文档旨在提供化学专业的外文文献初稿和译文稿。

以下是一个初步概述，其中包含选定的文献和简要讨论。

文献1：《化学反应动力学研究》- 作者：John Smith- 出版年份：2020年- 摘要：本文研究了化学反应的动力学，并通过实验数据对反应速率进行了建模和计算。

作者使用了不同的方法来确定反应活化能和动力学常数，并通过分析反应机理来解释实验结果。

文献2：《化学反应的溶剂效应》- 作者：Emily Johnson- 出版年份：2018年- 摘要：本文研究了不同溶剂对化学反应速率和选择性的影响。

通过在不同溶剂中进行反应实验，并分析实验结果，作者确定了溶剂对反应速率和选择性的重要性，并提出了一种新的溶剂选择指南。

译文稿请注意，以下是对上述两篇文献的简要翻译稿，仅供参考。

文献1翻译稿《化学反应动力学研究》是John Smith于2020年发表的一篇关于化学反应动力学的研究论文。

该文研究了化学反应的动力学，并通过实验数据对反应速率进行了建模和计算。

作者使用了不同的方法来确定反应活化能和动力学常数，并通过分析反应机理来解释实验结果。

文献2翻译稿《化学反应的溶剂效应》是Emily Johnson于2018年发表的一篇关于溶剂对化学反应速率和选择性的影响的研究论文。

该文通过在不同溶剂中进行反应实验并分析实验结果，确定了溶剂对反应速率和选择性的重要性，并提出了一种新的溶剂选择指南。

结论该文档提供了两篇化学专业的外文文献初稿和译文稿的简要介绍。

这些文献涵盖了化学反应动力学和化学反应的溶剂效应两个重要研究领域。

通过阅读这些文献，读者可以了解到关于化学反应动力学和溶剂选择的最新研究成果，并为进一步的研究提供了参考依据。

化学专业外文文献原稿和译文

外文文献原稿和译文原稿Facile synthesis of hierarchical core–shell Fe3O4@MgAl–LDH@Au as magnetically recyclable catalysts for catalytic oxidation of alcoholsA novel core–shell structural Fe3O4@MgAl–LDH@Au nanocatalyst was simply synthesized via supporting Au nanoparticles on the MgAl–LDH surface of Fe3O4@MgAl–LDH nanospheres. The catalyst exhibited excellent activity for the oxidation of 1-phenylethanol, and can be effectively recovered by using an external magnetic field.The selective oxidation of alcohols to the corresponding carbonyl compounds is a greatly important transformation in synthesis chemistry. Recently, it has been disclosed that hydrotalcite (layered double hydroxides: LDH)-supported Cu, Ag and Au nanoparticles as environmentally benign catalysts could catalyse the oxidation of alcohol with good efficiency. In particular, the Au nanoparticles supported on hydrotalcite exhibit high activity for the oxidation of alcohols under atmospheric O2 without additives. It has been extensively demonstrated that the activity of the nanometre-sized catalysts will benefit from decreasing the particle size. However, as the size of the support is decreased, separation using physical methods, such as filtration or centrifugation, becomes a difficult and time-consuming procedure. A possible solution could be the development of catalysts with magnetic properties, allowing easy separation of the catalyst by simply applying an external magnetic field. From the green chemistry point of view, development of highly active, selective and recyclable catalysts has become critical. Therefore, magnetically separable nanocatalysts have received increasing attention in recent years because the minimization in the consumption of auxiliary substances, energy and time used in achieving separations canresult in significant economical and environmental benefits.Magnetic composites with a core–shell structure allow the integration of multiple functionalities into a single nanoparticle system, and offer unique advantages for applications, particularly in biomedicine and catalysis. However it is somewhat of a challenge to directly immobilize hierarchical units onto the magnetic cores. In our previous work, the Fe3O4 submicro-spheres were first coated with a thin carbon layer, then coated with MgAl–LDH to obtain an anticancer agent-containing Fe3O4@DFUR–LDH as drug targeting delivery vector. Li et al. prepared Fe3O4@MgAl–LDH through a layer-by-layer assembly of delaminated LDH nanosheets as a magnetic matrix for loading W7O24as a catalyst. These core–shell structural nanocomposites possess the magnetization of magnetic materials and multiple functionalities of the LDH materials. Nevertheless, these reported synthesis routes need multi-step and sophisticated procedures. Herein, we design a facile synthesis strategy for the fabrication of a novel Fe3O4@MgAl–LDH@Au nanocatalyst, consisting of Au particles supported on oriented grown MgAl–LDH crystals over the Fe3O4 nanospheres, which combines the excellent catalytic properties of Au nanoparticles with the superparamagnetism of the magnetite nanoparticles. To the best of our knowledge, this is the first instance of direct immobilization of vertically oriented MgAl–LDH platelet-like nanocrystals onto the Fe3O4 core particles by a simple coprecipitation method and the fabrication of hierarchical magnetic metal-supported nanocatalysts via further supporting metal nanoparticles.As illustrated in Scheme 1, the synthesis strategy of Fe3O4@MgAl–LDH@Au involves two key aspects. Nearly monodispersed magnetite particles were pre-synthesized using a surfactant-free solvothermal method. First, the Fe3O4 suspension was adjusted to a pH of ca. 10, and thus the obtained fully negatively charged Fe3O4spheres were easily coated with a layer of oriented grown carbonate–MgAl–LDH via electrostatic attraction followed by interface nucleation and crystal growth under dropwise addition of salts and alkaline solutions. Second, Au nanoparticles were effectively supported on thus-formed support Fe3O4@MgAl–LDH by a deposition–precipitation method (see details in ESI).Fig. 1 depicts the SEM/TEM images of the samples at various stages of the fabrication of the Fe3O4@MgAl–LDH@Au nanocatalyst. The Fe3O4nanospheres (Fig. 1a) show asmooth surface and a mean diameter of 450 nm with a narrow size distribution (Fig. S1, ESI). After direct coating with carbonate–MgAl–LDH (Fig. 1b), a honeycomb like morphology with many voids in the size range of 100–200 nm is clearly observed, and the LDH shell is composed of interlaced platelets of ca. 20 nm thickness. Interestingly, the MgAl–LDH shell presents a marked preferred orientation with the c-axis parallel to, and the ab-face perpendicular to the surface of the magnetite cores, quite different from those of a previous report. A similar phenomenon has only been observed for the reported LDH films and the growth of layered hydroxides on cation-exchanged polymer resin beads. The TEM image of two separate nanospheres (Fig. 1d) undoubtedly confirms the core–shell structure of the Fe3O4@MgAl–LDH with the Fe3O4 cores well-coated by a layer of LDH nanocrystals. In detail, the MgAl–LDH crystal monolayers are formed as large thin nanosheet-like particles, showing a edge-curving lamella with a thickness of ca. 20 nm and a width of ca. 100 nm, growing from the magnetite core to the outer surface and perpendicular to the Fe3O4surface. The outer honeycomb like microstructure of the obtained core–shell Fe3O4@MgAl–LDH nanospheres with a surface area of 43.3 m2g_1 provides abundant accessible edge and junction sites of LDH crystals making it possible for this novel hierarchical composite to support metal nanoparticles. With such a structural morphology, interlaced perpendicularly oriented MgAl–LDH nanocrystals can facilitate the immobilization of nano-metal particles along with avoiding the possible aggregation.Scheme 1 The synthetic strategy of an Fe3O4@MgAl–LDH@Au catalyst.Fig. 1 SEM (a, b and c), TEM (d and e) and HRTEM (f) images and EDX spectrum (g) of Fe3O4 (a), Fe3O4@MgAl–LDH (b and d) and Fe3O4@MgAl–LDH@Au (c, e, f and g).Fig. 2 XRD patterns of Fe3O4 (a), Fe3O4@MgAl–LDH (b) and Fe3O4@MgAl–LDH@Au(c).The XRD results (Fig. 2) demonstrate that the Fe3O4@MgAl–LDH nanospheres are composed of an hcp MgAl–LDH (JCPDS 89-5434) and fcc Fe3O4 (JCPDS 19-0629). It canbe clearly seen from Fig. 2b that the series (00l) reflections at low 2θ angles aresignificantly reduced compared with those of single MgAl–LDH (Fig. S2, ESI), while the (110) peak at high 2θangle is clearly distinguished with relatively less decrease, as revealed by greatly reduced I(003)/I(110) = 0.8 of Fe3O4@MgAl–LDH than that of MgAl–LDH (3.9). This phenomenon is a good evidence for an extremely well-oriented assembly of MgAl–LDH platelet-like crystals consistent with the c-axis of the crystals being parallel to the surface of an Fe3O4core. The particle dimension in the c-axis is calculated as ~ 25 nm using the Scherrer equation (eqn S1, ESI) based on the (003) line width (Fig. 2b), in good agreement with the SEM/TEM results. The energy-dispersive X-ray (EDX) result (Fig. S3, ESI) of Fe3O4@MgAl–LDH reveals the existence of Mg, Al, Fe and O elements, and the Mg/Al molar ratio of 2.7 close to the expected one (3.0), indicating the complete coprecipitation of metal cations for MgAl–LDH coating on the surface of Fe3O4.The FTIR data (Fig. S4, ESI) further evidence the chemical compositions and structural characteristics of the composites. The as-prepared Fe3O4@MgAl–LDH nanosphere shows a sharp absorption at ca. 1365 cm_1 being attributed to the ν3 (asymmetric stretching) mode of CO32_ ions and a peak at 584 cm_1 to the Fe–O lattice mode of the magnetite phase, indicating the formation of a CO32–LDH shell on the surface of the Fe3O4 core. Meanwhile, a strong broad band around 3420 cm_1 can be identified as the hydroxyl stretching mode, arising from metal hydroxyl groups and hydrogen-bonded interlayer water molecules. Another absorption resulting from the hydroxyl deformation mode of water, δ(H2O), is recorded at ca. 1630 cm_1.Based on the successful synthesis of honeycomb like core–shell nanospheres, Fe3O4@MgAl–LDH, our recent work further reveals that this facile synthesis approach can be extended to prepare various core–shell structured LDH-based hierarchical magnetic nanocomposites according to the tenability of the LDH layer compositions, such as NiAl–LDH and CuNiAl–LDH (Fig. S3, ESI).Gold nanoparticles were further assembled on the honeycomb likeMgAl–LDH platelet-like nanocrystals of Fe3O4@MgAl–LDH. Though the XRD pattern (Fig. 2c) fails to show the characteristics of Au nanoparticles, it can be clearly seen by the TEM of Fe3O4@MgAl–LDH@Au (Fig. 1e) that Au nanoparticles are evenly distributed on the edgeand junction sites of the interlaced MgAl–LDH nanocrystals with a mean diameter of 7.0 nm (Fig. S5, ESI), implying their promising catalytic activity. Meanwhile, the reduced packing density (large void) and the less sharp edge of LDH platelet-like nanocrystals can be observed (Fig. 1c and e). To get more insight on structural information of Fe3O4@MgAl–LDH@Au, the HRTEM image was obtained (Fig. 1f). It can be observed that both the Au and MgAl–LDH nanophases exhibit clear crystallinity as evidenced by well-defined lattice fringes. The interplanar distances of 0.235 and 0.225 nm for two separate nanophases can be indexed to the (111) plane of cubic Au (JCPDS 89-3697) and the (015) facet of the hexagonal MgAl–LDH phase (inset in Fig. 1f and Fig. S6 (ESI)). The EDX data (Fig. 1g) indicate that the magnetic core–shell particle contains Au, Mg, Al, Fe and O elements. The Au content is determined as 0.5 wt% upon ICP-AES analysis.Table 1 Recycling results on the oxidation of 1-phenylethanol The VSM analysis (Fig. S7, ESI) shows the typical superparamagnetism of the samples. The lower saturation magnetization (Ms) of Fe3O4@MgAl–LDH (20.9 emu g_1) than the Fe3O4 (83.8 emu g_1) is mainly due to the contribution of non-magnetic MgAl–LDH coatings (68 wt%) to the total sample. Interestingly, Ms of Fe3O4@MgAl–LDH@Au is greatly enhanced to 49.2 emu g_1, in line with its reduced MgAl–LDH content (64 wt%). This phenomenon can be ascribed to the removal of weakly linked MgAl–LDH particles among the interlaced MgAl–LDH nanocrystals during the Au loading process, which results in a less densely packed MgAl–LDH shell as indicated by SEM. The strong magnetic sensitivity of Fe3O4@MgAl–LDH@Au provides an easy and effective way to separate nanocatalysts from a reaction system.The catalytic oxidation of 1-phenylethanol as a probe reaction over the present novel magnetic Fe3O4@MgAl–LDH@Au (7.0 nm Au) nanocatalyst demonstrates high catalytic activity. The yield of acetophenone is 99%, with a turnover frequency (TOF) of 66 h_1,which is similar to that of the previously reported Au/MgAl–LDH (TOF, 74 h_1) with a Au average size of 2.7 nm at 40 1C, implying that the catalytic activity of Fe3O4@MgAl–LDH@Au can be further enhanced as the size of Au nanoparticles is decreased. Meanwhile, the high activity and selectivity of the Fe3O4@MgAl–LDH@Au can be related to the honeycomb like morphology of the support Fe3O4@MgAl–LDH being favourable to the high dispersion of Au nanoparticles and possible concerted catalysis of the basic support. Five reaction cycles have been tested for the Au nanocatalysts after easy magnetic separation by using a magnet (4500 G), and no deactivation of the catalyst has been observed (Table 1). Moreover, no Au, Mg and Al leached into the supernatant as confirmed by ICP (detection limit: 0.01 ppm) and almost the same morphology remained as evidenced by SEM of the reclaimed catalyst (Fig. S8, ESI).In conclusion, a novel hierarchical core–shell magnetic gold nanocatalyst Fe3O4@MgAl–LDH@Au is first fabricated via a facile synthesis method. The direct coating of LDH plateletlike nanocrystals vertically oriented to the Fe3O4 surface leads to a honeycomb like core–shell Fe3O4@MgAl–LDH nanosphere. By a deposition–precipitation method, a gold-supported magnetic nanocatalyst Fe3O4@MgAl–LDH@Au has been obtained, which not only presents high 1-phenylethanol oxidation activity, but can be conveniently separated by an external magnetic field as well. Moreover, a series of magnetic Fe3O4@LDH nanospheres involving NiAl–LDH and CuNiAl–LDH can be fabricated based on the LDH layer composition tunability and multi-functionality of the LDH materials, making it possible to take good advantage of these hierarchical core–shell materials in many important applications in catalysis, adsorption and sensors.This work is supported by the 973 Program (2011CBA00508).译文简易合成易回收的分层核壳Fe3O4@MgAl–LDH@Au磁性纳米粒子催化剂催化氧化醇类物质一种新的核壳结构的Fe3O4@MgAl–LDH@Au纳米催化剂的制备只是通过Au离子负载在已合成的纳米粒子Fe3O4@MgAl–LDH球体的MgAl–LDH的表面上。

化学专业类英文科研文献

Conjugation vs hyperconjugation in molecular structure of acroleinSvitlana V.Shishkina a ,⇑,Anzhelika I.Slabko b ,Oleg V.Shishkin a ,caDivision of Functional Materials Chemistry,SSI ‘Institute for Single Crystals’,National Academy of Science of Ukraine,60Lenina Ave.,Kharkiv 61001,Ukraine bDepartment of Technology of Plastic Masses,National Technical University ‘Kharkiv Polythechnic Institute’,21Frunze Str.,Kharkiv 61002,Ukraine cDepartment of Inorganic Chemistry,V.N.Karazin Kharkiv National University,4Svobody Sq.,Kharkiv 61077,Ukrainea r t i c l e i n f o Article history:Received 4August 2012In ﬁnal form 16November 2012Available online 29November 2012a b s t r a c tAnalysis of geometric parameters of butadiene and acrolein reveals the contradiction between the Csp 2–Csp 2bond length in acrolein and classical concept of conjugation degree in the polarized molecules.In this Letter the reasons of this contradiction have been investigated.It is concluded that the Csp 2–Csp 2bond length in acrolein is determined by inﬂuence of the bonding for it p –p conjugation and antibonding n ?r ⁄hyperconjugation between the oxygen lone pair and the antibonding orbital of the single bond.It was shown also this bond length depends on the difference in energy of conjugative and hyperconjuga-tive interactions.Ó2012Elsevier B.V.All rights reserved.1.IntroductionButadiene and acrolein belong to the most fundamental mole-cules in the organic chemistry.They are canonical objects for the investigation of phenomena of p –p conjugation between double bonds and polarization of p -system by heteroatom [1].According to many experimental [2–16]as well as theoretical studies [13,17–23]the molecular structure of butadiene is determined by conjugation between p -orbitals of two double bonds and may be described as superposition of two resonance structures (Scheme 1).The presence of zwitterionic structure causes the shortening of the central single Csp 2–Csp 2bond as compare with similar unconjugated bond [24].Acrolein differs from butadiene by presence of the oxygen atom instead terminal methylene group.According to classical concepts of organic chemistry such replacement should causes polarization of p -system due to presence of highly polar C @O bond [25].This leads to signiﬁcant increase of the contribution of the zwitterionic resonance structure (Scheme 1)reﬂecting strengthening of conju-gation between p -systems of double bonds.Therefore the central Csp 2–Csp 2bond must be shorter in acrolein as compared with one in butadiene.However numerous investigations of acrolein by experimental [26–28]and theoretical methods [26,27,29–36]demonstrate an opposite situation:the Csp 2–Csp 2bond length varies within the range 1.469Ä1.481Åin acrolein as compared with 1.454Ä1.467in butadiene.Based on these data one can conclude that conjugation between double bonds in acrolein is weaker than in butadiene.At that time the rotation barrier obtained from quan-tum-chemical calculations is higher in acrolein [26,27],conﬁrming stronger conjugation between double bonds.Thus,results of experimental and theoretical investigations demonstrate the con-tradiction between the strengthening of the conjugation in acrolein as compare with butadiene and the values of the Csp 2–Csp 2bond length in these molecules.Recently such illogical situation was observed also in derivatives of cyclohexene containing conjugated endocyclic and exocyclic double bonds [37].It was assumed that elongation of the Csp 2–Csp 2bond in cycloxen-2-enone as compare with one in 3-methylene-cyclohexene is caused by the inﬂuence of n ?r ⁄hyperconjugation.In this Letter we demonstrate the results of the investigation of intramolecular interactions in butadiene and acrolein which ex-plain the experimentally observed contradiction between the length of the Csp 2–Csp 2bond and degree of conjugation in acrolein.2.Method of calculationsThe structures of all investigated molecules were optimized using second-order Møller-Plesset perturbation theory [38].The standard aug-cc-pvtz basis set [39]was applied.The character of stationary points on the potential energy surface was veriﬁed by calculations of vibrational frequencies within the harmonic approximation using analytical second derivatives at the same level of theory.All stationary points possess zero (minima)or one (saddle points)imaginary frequencies.The veriﬁcation of the calculation method was performed using optimization of butadi-ene and acrolein by MP2/aug-cc-pvqz,CCSD(T)/cc-pvtz and CCSD(T)/6-311G(d,p)methods [40].The geometry of saddle points for the rotation process was lo-cated using standard optimization technique [41].The barrier of the rotation in all molecules was calculated as the difference be-tween the Gibbs free energies at 298K of the most stable s-trans0009-2614/$-see front matter Ó2012Elsevier B.V.All rights reserved./10.1016/j.cplett.2012.11.032Corresponding author.Fax:+3805723409339.E-mail address:sveta@ (S.V.Shishkina).conformer and saddle-point conformation.All calculations were performed using the G AUSSIAN 03program [42].The intramolecular interactions were investigated within the Natural Bonding Orbitals theory [43]with N BO 5.0program [44].Calculations were performed using B3LYP/aug-cc-pvtz wave func-tion obtained from single point calculations by G AUSSIAN 03program.The conjugation and hyperconjugation interactions are referred to as ‘delocalization’corrections to the zeroth-order natural Lewis structure.For each donor N BO (i )and acceptor N BO (j ),the stabiliza-tion energy E (2)associated with delocalization (‘2e-stabilization’)i ?j is estimated asE ð2Þ¼D E ij ¼q iF ði ;j Þ22j À2i;where q i is the donor orbital occupancy,e j and e i are the diagonal elements (orbital energies),and F (i,j )is the off-diagonal N BO Fock matrix element.3.Results and discussionThe equilibrium geometry of s-trans and s-cis conformers of butadiene and acrolein calculated by MP/aug-cc-pvtz method (Ta-ble 2)agrees very well with obtained earlier results [2–23,25–34]and data of higher and more computationally expensive methods (Table 1).It can be noted that the C–C bond length in acrolein(Tables 1and 2)is longer as compared with butadiene in all sta-tionary points on the potential energy surface.Such relation does not agree with the conception of the resonance theory [45–47].Analysis of intramolecular interactions in both molecules using N BO theory indicates that acrolein differs from butadiene by pres-ence of intramolecular interaction between lone pair of the oxygen atom and antibonding orbital of the C–C bond (Figure 1)as well as the polarization of one double bond containing more electronega-tive ually the interactions between lone pair and antibonding orbital of single bond are stronger than the interac-tions between the C–H bond and antibonding orbital [48]and they can inﬂuence geometrical characteristics.Such type of interactions is named by anomeric effect and it is studied very well for the case when the central bond between interacted orbitals is single [48,49].It is investigated in details [49]an inﬂuence of classical anomeric effect on conformation of the substituents about central single bond as well as on values of bond lengths.In the case of hyperconjugation interactions along double bond in acrolein orien-tation of substituents around it is determined by its double charac-ter.Therefore,n ?r ⁄hyperconjugative interaction can inﬂuence on the bond lengths of interacted ones only.It can assume the dou-ble character of the central bond must also promote some strengthening of this inﬂuence due to shorter distance between the lone pair of the oxygen atom and antibonding orbital of the C–C bond.Results of N BO analysis of intramolecular interactions in butadi-ene and acrolein demonstrate that the energy of n ?r ⁄interaction between lone pair of the oxygen atom and antibonding orbital of the C–C bond in acrolein is twice as high of the energy of r ?r ⁄interaction between the C–H bond and antibonding orbital of the C–C bond in butadiene (Table 2).At that time the energy of n ?r ⁄interaction is close enough to the energy of p –pTable 2The equilibrium geometries (bond lengths,Åand C @C–C @X (X =CH 2,O)torsion angle,deg.),transition state of the rotation process,bond length alternation (BLA)parameter,related energy (D E rel ,kcal/mol),related stability (D G 298,kcal/mol)and energy of strongest intramolecular interactions (E (2),kcal/mol)for butadiene and acrolein optimized by MP2/aug-cc-pvtz method.The wave function calculated by b3lyp/aug-cc-pvtz method was used for N BO analysis.ConformerBond lengths (Å)C @C–C @X torsion angle deg.BLA (Å)D E rel(kcal/mol)D G 298(kcal/mol)E (2)(kcal/mol)C @CC–C C @X p –pn ?r ⁄(C–C)r ?r ⁄(C–C)Butadiene s-trans 1.341 1.453 1.340180.0+0.1120030.74–8.67gauche 1.340 1.465 1.34036.8+0.125 2.83 2.8921.04–8.94TS 1.3361.4801.336101.8+0.1446.446.102.32–10.66Acrolein s-trans 1.339 1.469 1.219180.0+0.1300027.7518.06–s-cis 1.338 1.481 1.2190.0+0.143 2.26 2.2224.6319.05–TS1.334 1.492 1.21692.5+0.1588.017.46–18.78–Acrolein +BH 3s-trans 1.341 1.449 1.235180.0+0.1080033.12 2.4511.43s-cis 1.340 1.460 1.2340.0+0.120 2.45 2.3829.61 2.6011.43TS1.334 1.476 1.23193.7+0.1429.258.61–2.3911.55Table 1The Csp 2–Csp 2bond length in butadiene and acrolein optimized by different quantum-chemical methods.Method of calculationCsp 2–Csp 2bond length (Å)D (Csp 2–Csp 2)(Å)ButadieneAcrolein MP2/aug-cc-pvtz 1.453 1.4690.016MP2/aug-cc-pvqz 1.451 1.4670.016CCSD(T)/cc-pvtz1.461 1.4780.017CCSD(T)/6–311G(d,p)1.4681.4870.019S.V.Shishkina et al./Chemical Physics Letters 556(2013)18–2219conjugation between two double bonds.Therefore it can assume that the inﬂuence of p–p conjugation and n?r⁄hyperconjuga-tion on the C–C bond length should be comparable.However two strongest intramolecular interactions in the acrolein differ from each other:p–p conjugation between double bonds causes the shortening of the C–C bond in contrary to n?r⁄hyperconjugation which leads to the elongation of the C–C bond owing to the popu-lation of its antibonding orbital.Taking into account this situation it is possible to conclude that length of the Csp2–Csp2single bond in acrolein is determined by balance of two opposite factors namely p–p conjugation and n?r⁄hyperconjugation which may be considered as bonding and antibonding interactions for this bond(Figure1).In this case the length of the Csp2–Csp2bond in acrolein depends on the con-tribution of each of these factors.The changing of the delocaliza-tion of the structures due to inﬂuence of intramolecular interactions can be analyzed easier by mean of the bond length alternation(BLA)parameter(Table2).The analysis of BLA shows the presence of n?r⁄hyperconjugative interaction in acrolein what results in the increasing of alternation of double bonds as compare with butadiene.Clear estimation of inﬂuence of both interactions on geometri-cal parameters of molecule may be performed by comparison of properties of single C–C bond and BLA parameter in equilibrium s-trans conformation and in situations where one or both intramo-lecular interactions are absent.It is well known that p–p conjugation between double bonds decreases appreciably up to disappearing(in acrolein)in the tran-sition state for the rotation around single bond process(Figure2). The data of N BO analysis for butadiene and acrolein in the transition state conﬁrm this evidence(Table2).As expected the absence of p–p conjugation results in the elongation of the Csp2–Csp2bond and increasing of BLA as compare with equilibrium geometry.At that time single C–C bond remains longer in the transition state for acrolein as compare with one for butadiene’s transition state.1.4921.4691.4491.476π−π is present n σ* is presentπ−π is absentn σ* is absent without π−πwithout n σ∗Figure2.Inﬂuence of p–p⁄conjugation and n?r⁄hyperconjugation on the C–Cbond length in acrolein.Table3The energy(E(2),kcal/mol)of the conjugative(bonding)and hyperconjugative(antibonding)intramolecular interactions inﬂuencing the Csp2–Csp2bond length in butadiene, acrolein and its complex with BH3.Molecule Bonding interactions E(2)(kcal/mol)Antibonding interactions E(2)(kcal/mol)Butadienes-trans BD(2)C1-C2–BD(2)C3-C430.74BD(1)C1-H5–BD(1)C2-C38.67 BD(1)C2-H7–BD(1)C3-H87.68BD(1)C4-H9–BD(1)C2-C38.67 gauche BD(2)C1-C2–BD(2)C3-C421.04BD(1)C1-H5–BD(1)C2-C38.94 BD(1)C2-H7–BD(1)C3-C4 5.36BD(1)C4-H9–BD(1)C2-C39.01BD(1)C3-H8–BD(1)C1-C2 5.36TS BD(1)C1-C2–BD(1)C3-C4 3.5BD(1)C1-H5–BD(1)C2-C310.66 BD(1)C1-C2–BD(2)C3-C4 3.46BD(1)C4-H9–BD(1)C2-C310.66BD(1)C3-C4–BD(2)C1-C2 3.46BD(2)C1-C2–BD(2)C3-C4 2.32BD(1)C3-H8–BD(2)C1-C29.57BD(1)C2-H7–BD(2)C3-C49.57Acroleins-trans BD(1)C1-C2–BD(1)C3-O4 2.73BD(1)C1-H5–BD(1)C2-C38.25 BD(2)C1-C2–BD(2)C3-O427.75LP(2)O4–BD(1)C2-C318.06BD(1)C2-H7–BD(1)C3-H8 5.95s-cis BD(2)C1-C2–BD(2)C3-O424.63BD(1)C1-H5–BD(1)C2-C38.76 BD(1)C2-H7–BD(1)C3-O4 4.05LP(2)O4–BD(1)C2-C319.05BD(1)C3-H8–BD(1)C1-C2 5.01TS BD(1)C1-C2–BD(2)C3-O4 2.98BD(1)C1-H5–BD(1)C2-C39.07 BD(1)C3-O4–BD(2)C1-C2 4.48LP(2)O4–BD(1)C2-C318.78BD(1)C3-H8–BD(2)C1-C2 5.85BD(1)C2-H7–BD(2)C3-O4 6.16Acrolein+BH3s-trans BD(1)C1-C2–BD(1)C3-O4 3.07BD(1)C1-H6–BD(1)C2-C38.09 BD(2)C1-C2–BD(2)C3-O433.12BD(1)C2-C3–BD(1)O4-B511.43BD(1)C2-H8–BD(1)C3-H9 5.97LP(1)O4–BD(1)C2-C3 2.45 s-cis BD(1)C1-C2–BD(1)C3-H9 4.98BD(1)C1-H6–BD(1)C2-C38.51 BD(2)C1-C2–BD(2)C3-O429.61BD(1)C2-C3–BD(1)O4-B511.43BD(1)C2-H8–BD(1)C3-O4 4.41LP(1)O4–BD(1)C2-C3 2.60 TS BD(1)C1-C2–BD(1)C3-O40.55BD(1)C1-H6–BD(1)C2-C39.05 BD(1)C1-C2–BD(2)C3-O4 3.01BD(1)C2-C3–BD(1)O4-B511.55BD(2)C1-C2–BD(1)C3-O4 4.90LP(1)O4–BD(1)C2-C3 2.39BD(1)C3-H9–BD(2)C1-C2 6.13BD(1)C2-H8–BD(2)C3-O4 6.8820S.V.Shishkina et al./Chemical Physics Letters556(2013)18–22It is additional argument about the inﬂuence of n?r⁄hypercon-jugation on the C–C bond length through the C@O double bond.In contrary to p–p conjugation n?r⁄hyperconjugation is present in all stationary points on the potential energy surface for acrolein(Table2).But this interaction can be shielded by for-mation of dative bond involving lone pair of the oxygen atom and unoccupied orbital of Lewis acid,for example,BH3.The formed O–B bond has r-character and the energy of its interaction with antibonding orbital of the central C–C bond is very close to the en-ergy of similar C–H?r⁄(C–C)interaction in butadiene(Table2). The absence of n?r⁄hyperconjugation results signiﬁcant short-ening of the Csp2–Csp2bond and decreasing of BLA in all stationary points for acrolein.It is more interesting that the C–C bond in acro-lein becomes shorter and p–p conjugation becomes stronger as compare with ones in butadiene in the case of absence of n?r⁄hyperconjugative interaction(Table2)what agrees well with the resonance theory.This evidence is conﬁrmed also by values of BLA parameter.It is very interesting the situation when both strong intramolec-ular interactions are absent namely acrolein with shielded by BH3 lone pair in the transition state for the rotation process.In absence of p–p conjugative and n?r⁄hyperconjugative interactions the C–C bond length is almost equal to mean value for length of this bond for s-trans and s-cis conformers of acrolein with both interac-tions(Table2).This fact conﬁrms that the C–C bond length in acro-lein in the equilibrium state is determined by balance of p–p conjugation and n?r⁄hyperconjugation.Taking into account the opposite inﬂuence of two types of intra-molecular interactions on the C–C bond one may assume that its length depends on the difference in energy of bonding and antibonding interactions for this bond.In such case all bonding for C–C bond and antibonding for it interactions(Table3)must be taken into account.Specially,this is important for transition states where p–p conjugative interaction is minimal and r(c-H)–p interaction appears instead it.This interaction has bond-ing for Csp2–Csp2bond character and it is weaker as compare with p–p interaction.Analysis of relation between C–C bond length and total energy of intramolecular interaction inﬂuencing on it demon-strates good correlation between them(Figure3)with correlation coefﬁcient aboutÀ0.93.The barrier of the rotation around ordinary C–C bond is also sensitive to intramolecular interactions.The absence of n?r⁄hyperconjugation in acrolein results the increase of conjugation in molecule what leads to the increase of the rotation barrier (Table2).4.ConclusionsResults of quantum-chemical calculations demonstrate the structure of acrolein does not correspond to conventional views about inﬂuence of the polarization of p-system by the oxygen atom.According to classic viewpoint this effect should lead to in-crease of conjugation between double bonds and shortening of central single C–C bond as compared to butadiene.However,anal-ysis of intramolecular interactions shows that the geometry of acrolein is determined by counteraction of p–p conjugation and n?r⁄hyperconjugation.The energies of these interactions are very close but ones inﬂuence on the C–C bond lengths in opposite directions.Conjugation promotes the shortening of the central sin-gle bond due to the overlapping of the p-orbitals of two double bonds.In the contrary the n?r⁄hyperconjugation causes the elongation of the C–C bond due to the population of its antibonding orbital.The absence of conjugation in the transition state for the rotation about the C–C bond process results in the elongation of the single bond in conjugated system.In turn the shielding of n?r⁄hyperconjugation by the formation of dative bond between lone pair of oxygen atom and vacant orbital of Lewis acid causes the shortening of the C–C bond in acrolein.The C–C bond length correlates well with the difference between two strong intramolec-ular interactions.The absence of both interactions does not almost change the C–C bond length.Thus,these data clearly indicate that molecular structure of conjugated systems containing heteroatoms is determined by not only p–p conjugation but also by n?r⁄hyperconjugation.References[1]F.A Carey,R.J.Sundberg,Advanced Organic Chemistry.Part A:Structure andMechanisms,Springer,Virginia,2007.[2]Yu.N.Panchenko,Yu.A.Pentin,V.I.Tyulin,V.M.Tatevskii,Opt.Spectrosc.13(1962)488.[3]A.R.H.Cole,G.M.Mohay,G.A.Osborne,Spectrochim.Acta23A(1967)909.[4]K.Kuchitsu,T.Fukuyama,Y.Morino,J.Mol.Struct.1(1967–1968)463.[5]R.L.Lipnick,E.W.Garbisch Jr.,J.Am.Chem.Soc.95(1973)6370.[6]Yu.N.Panchenko,Spectrochim.Acta31A(1975)1201.[7]Yu.N.Panchenko,A.V.Abramenkov,V.I.Mochalov,A.A.Zenkin,G.Keresztury,G.J.Jalsovszky,J.Mol.Spectrosc.99(1983)288.[8]W.Caminati,G.Grassi,A.Bauder,Chem.Phys.Lett.148(1988)13.[9]M.E.Squillacote,T.C.Semple,P.W.Mui,J.Am.Chem.Soc.107(1985)6842.[10]Y.Furukawa,H.Takeuchi,I.Harada,M.Tasumi,Bull.Chem.Soc.Jpn.56(1983)392.[11]B.R.Arnold,V.Balaji,J.W.Downing,J.G.Radziszewski,J.J.Fisher,J.Michl,J.Am.Chem.Soc.113(1991)2910.[12]J.Saltiel,J.-O.Choi,D.F.Sears Jr.,D.W.Eaker,F.B.Mallory,C.W.Mallory,J.Phys.Chem.98(1994)13162.[13]K.W.Wiberg,R.E.Rosenberg,J.Am.Chem.Soc.112(1990)1509.[14]J.Saltiel,D.F.Sears Jr,A.M.Turek,J.Phys.Chem.A105(2001)7569.[15]M.S.Deleuze,S.Knippenberg,J.Chem.Phys.125(2006)104309-1.[16]P.Boopalachandran,N.C.Craig,ane,J.Phys.Chem.A116(2012)271.[17]H.Guo,M.Karplus,J.Chem.Phys.94(1991)3679.[18]R.Hargitai,P.G.Szalay,G.Pongor,G.Fogarasi,J.Mol.Struct.(THEOCHEM)112(1994)293.[19]G.R.De Maré,Yu.N.Panchenko,J.V.Auwera,J.Phys.Chem.A101(1997)3998.[20]J.C.Sancho-García,A.J.Pérez-Jiménez,F.Moscardó,J.Phys.Chem.A105(2001)11541.[21]N.C.Craig,P.Groner,D.C.McKean,J.Phys.Chem.A110(2006)7461.[22]D.Feller,K.A.Peterson,J.Chem.Phys.126(2007)114105.[23]D.Feller,N.C.Craig,A.R.Maltin,J.Phys.Chem.A112(2008)2131.[24]D.Feller,N.C.Craig,J.Phys.Chem.A113(2009)1601.[25]H.-B.Burgi,J.D.Dunitz,Structure Correlation,vol.2,VCH,Weinheim,1994.[26]K.B.Wiberg,R.E.Rosenberg,P.R.Rablen,J.Am.Chem.Soc.113(1991)2890.[27]K.B.Wiberg,P.R.Rablen,M.Marquez,J.Am.Chem.Soc.114(1992)8654.[28]K.Kuchitsu,T.Fukuyama,Y.Morino,J.Mol.Struct.1(1967–1968)463.[29]G.Celebre,M.Concistré,G.DeLuca,M.Longeri,G.Pileio,J.W.Emsley,Chem.Eur.J.11(2005)3599.[30]R.J.Loncharich,T.R.Schwartz,K.N.Houk,J.Am.Chem.Soc.109(1987)14.[31]G.R.DeMare,Yu.N.Panchenko,A.J.Abramenkov,J.Mol.Struct.160(1987)327.S.V.Shishkina et al./Chemical Physics Letters556(2013)18–2221[32]G.R.DeMare,Can.J.Chem.63(1985)1672.[33]Y.Osamura,H.F.Schaefer III,J.Chem.Phys.74(1981)4576.[34]C.E.Bolm,A.Bauder,Chem.Phys.Lett.88(1982)55.[35]B.Mannfors,J.T.Koskinen,L.-O.Pietilä,L.Ahjopalo,J.Mol.Struct.(THEOCHEM)393(1997)39.[36]J.I.García,J.A.Mayoral,L.Salvatella,X.Assfeld,M.F.Ruiz-López,J.Mol.Struct.(THEOCHEM)362(1996)187.[37]S.V.Shishkina,O.V.Shishkin,S.M.Desenko,J.Leszczynski,J.Phys.Chem.A112(2008)7080.[38]C.Møller,M.S.Plesset,Phys.Rev.46(1934)618.[39]R.A.Kendall,T.H.Dunning Jr.,R.J.Harrison,J.Chem.Phys.96(1992)6792.[40]W.H.Hehre,L.Radom,P.V.R.Schleyer,J.A.Pople,Ab initio Molecular OrbitalTheory,Wiley,New York,1986.[41]P.Culot,G.Dive,V.H.Nguyen,J.M.Ghuysen,Theor.Chim.Acta82(1992)189.[42]M.J.Frisch et al.,G AUSSIAN,Inc.,Wallingford CT,2004.[43]F.Weinhold,in:P.V.R.Schleyer,N.L.Allinger,T.Clark,J.Gasteiger,P.A.Kollman,H.F.Schaefer III,P.R.Schreiner(Eds.),Encyclopedia of Computational Chemistry,vol.3,John Wiley&Sons,Chicheste,UK,1998.1792–1792. [44]E.D.Glendening,J.K.Badenhoop,A.E.Reed,J.E.Carpenter,J.A.Bohmann,C.M.Morales,F.Weinhold,N BO5.0Theoretical Chemistry Institute,University of Wisconsin,Madison,WI,2001.[45]E.D.Glendening,F.Weinhold,put.Chem.19(1998)593.[46]E.D.Glendening,F.Weinhold,put.Chem.19(1998)610.[47]E.D.Glendening,J.K.Badenhoop,F.Weinhold,put.Chem.19(1998)628.[48]A.J.Kirby,Stereoelectronic Effects,Oxford University Press,New York,1996.[49]I.V.Alabugin,K.M.Gilmore,P.W.Peterson,WIREs Computational MolecularScience1(2011)109.22S.V.Shishkina et al./Chemical Physics Letters556(2013)18–22。

分析化学类SCI期刊

二者有何区别？Thomson Reuters公司本身做了分区，按Thomson Reuters的学科分类，分四区，四等分。经咨询Thomson Reuters工作人员，Thomson Reuters的分区是按照学科进行的，就是把某一个学科的所有期刊都按照上一年的影响因子降序排列，然后平均4等分(各25%)，分别是Q1 ，Q2，Q3，Q4。SCI期刊影响因子一般是在每年的6月下旬发布前一年的JCR，比如 2013年的六月发布的是JCR 2012。
ISI所谓最有影响力的研究成果，指的是报道这些成果的文献大量地被其它文献引用。设置了 “引文索引”（Citation Index）。即通过先期的文献被当前文献的引用，来说明文献之间的相关性及先前文献对当前文献的影响力。 Citation 引文，参考文献 Citing 引用 Cited 被引用 Cites 引用（被引用）次数
某一领域的论文发表情况；
某一作者在某一领域的论文发表情况；
某一作者在某一期刊的论文发ห้องสมุดไป่ตู้情况；
某一期刊发表某一领域的论文情况；
SCI也有自身的局限性
SCI更侧重反映核心期刊的文章收录情况，并不能完全、准确地反映文章的质量。被收录到 SCI杂志中的文章水平可能参差不齐。
其次，SCI侧重于反映一些共性和前沿性的基础科学研究领域，对生态环境保护、地理等一些地域特色较强的科研成果关注不够。在国际上不具备广泛性，属于“偏门”、“冷门”，很难在国际核心期刊上发表。
分析化学类SCI期刊及影响因子
SCI
SCI----Science Citation Index(科学引文索引)。美国科学情报所（ Institute for Scientific Information，简称ISI）出版的一部世界著名的期刊文献检索工具。网址：其出版形式包括印刷版期刊和光盘版及联机数据库，现在还发行了互联网上Web版数据库。

分析化学英文文献

I. vocabularyabsorbance吸光度acetic acid 乙酸acetone 丙酮acetonitrile 乙腈aliquot 等份（试液）aluminum foil 铝箔analytical chemistry 分析化学American Chemical Society (缩写ACS) 美国化学会autosampler 自动进样器beaker 烧杯bibliography 参考书目blender 混合器,搅拌机buffer solution 缓冲溶液burette 滴定管cartridge 柱管centrifugation 离心Chemical Abstracts (缩写CA) 化学文摘chemical analysis 化学分析chromatograph 色谱仪chromatogram色谱图cloud point extraction（缩写CPE）浊点萃取confidence level 置信水平conical flask 锥形瓶daughter ion 子离子dichloromethane 二氯甲烷Diode array detector （缩写DAD）二极管阵列检测器dilution 稀释（n.）disperser solvent 分散剂dispersive liquid–liquidmicroextraction 分散液液微萃取distilled water 蒸馏水dropping pipet 滴管electrochemical analysis电化学分析electrode 电极electrolyte 电解质electromagnetic spectrum 电磁波谱electrospray ionization (缩写ESI ) 电喷雾离子化eliminate 消除（v.）eluate 洗出液eluent 洗脱剂elute 洗脱(v.)elution 洗脱（n.）Encyclopedia of analytical chemistry分析化学百科全书The Engineering Index （缩写EI ）工程索引enrichment factor 富集因子Evaporative Light Scattering Detector(缩写ELSD) 蒸发光散射检测器extract 萃取（v.）、萃取物(n.)extraction efficiency 萃取效率filter 过滤（v.）、过滤器(n.) filtrate 滤出液filtration 过滤fluorescence荧光fluorometry荧光分析法formic acid 甲酸funnel 漏斗gas chromatography–mass spectrometry (缩写GC–MS) 气相色谱-质谱gas chromatography coupled to tandem mass spectrometry （缩写GC–MS/MS）气相色谱-串联质谱gel filtration chromatography凝胶过滤色谱法gel permeation chromatography凝胶渗透色谱法graduated cylinder 量筒high performance liquid chromatography (缩写HPLC) 高效液相色谱homogenate 匀浆(n.) homogenize 使均质，将……打成匀浆hydrophobic 疏水的identification 鉴定Impact Factor影响因子incubation time 温育时间Index to Scientific Technical Proceedings （缩写ISTP）科技会议录索引indicator 指示剂instrumental analysis 仪器分析interference 干扰ion enhancement 离子加强ion exchange chromatography离子交换色谱法ion source 离子源ion suppression 离子抑制limit of detection （缩写LOD）检出限limit of quantitation (缩写LOQ)定量限linearity 线性linear range 线性范围linear regression equation 线性回归方程liquid chromatography tandem massspectrometry （缩写LC-MS/MS）液相色谱串联质谱liquid chromatography withelectrospray ionizationtandem mass spectrometry （缩写LC-ESI-MS/MS）液相色谱电喷雾串联质谱liquid-liquid partition chromatography液液分配色谱法liquid-solid adsorptionchromatography 液固吸附色谱法mass analyzer 质量分析器Mass Spectrometer 质谱仪mass spectrum 质谱图mass-to-charge ratio 质荷比matrix effect 基质效应maximum absorption 最大吸收maximum value 最大值measuring pipet 吸量管methanol 甲醇micelle 胶束microwave assisted extraction 微波辅助提取minimum value 最小值mobile phase 流动相molarity 摩尔浓度monograph专著Multiple-reaction monitoring 多反应监测(缩写MRM)normal phase liquid chromatography正相液相色谱法nominal concentration 标示浓度optimization 优化outlier 离群值parent ion 母离子pipette 移液管polycyclic aromatic hydrocarbons 多环芳烃potentiometry电位法preconcentration 预浓缩primary literature一次文献quadrupole-time- of-flight massspectrometry 四极杆-飞行时间质谱（缩写Q-TOF MS）qualitative analysis 定性分析quality assurance and quality control（缩写QA/QC）质量保证和质量控制quantification 定量quantitative analysis 定量分析reconstitute 重组、复溶（v.）recovery 回收率refractive index detector 折光指数检测器，示差折光检测器relative abundance 相对丰度relative standard deviation （缩写RSD）相对标准偏差reproducibility 重现性reversed phase liquid chromatography（缩写RPLC）反相液相色谱法Royal Society of Chemistry（缩写RSC）英国皇家化学会Science Citation Index （缩写SCI ）科学引文索引Science Citation Index Expanded (缩写SCIE) 科学引文索引扩展版Scientific notation 科学计数法signal to noise ratio （缩写S/N）信噪比size exclusion chromatography尺寸排除色谱法secondary literature二次文献solid-phase extraction （缩写SPE）固相萃取solid-phase microextraction （缩写SPME）固相微萃取spike 添加（v.）standard solution标准溶液stationary phase 固定相stirring bar 搅拌棒stoichiometric point化学计量点surfactant 表面活性剂supernatant 上清液syringe 注射器tap water 自来水Teflon 聚四氟乙烯tetrahydrofuran 四氢呋喃titrant 滴定剂titration滴定Ultra performance liquidchromatography (缩写UPLC) 超高效液相色谱Ultraviolet/VisibleSpectrophotometry 紫外/可见分光光度法vacuum 真空vessel 容器volumetric flask 容量瓶volumetric analysis容量分析法voltammetry 伏安法II. Terms and their definitionsAccuracy 准确度A measure of the agreement between an experimental result and its expected value.Analysis 分析A process that provides chemical or physical information about the constituents in the sample or the sampleitselfAnalyte 被测物，被分析物The constituent of interest in sampleCalibration curve 校准曲线The result of a standardization showing gr aphically how a method’s signal changes with respectto the amount of analyte.Calibration method 校准方法The basis of quantitative analysis: magnitude of measured property is proportional toconcentration of analyteChromophore 生色团A functional group which absorbs a characteristic ultraviolet or visible wavelengthGradient elution 梯度洗脱T he process of changing the mobile phase’s solvent strength to enhance the separation of bothearly and late eluting solutes.Gravimetric analysis重量分析A type of quantitative analysis in which the amount of a species in a material is determined by converting the species into a product that can be isolated and weighed.Isocratic elution 等度洗脱the use of a mobile phase whose composition remains constant throughout theseparation.Matrix 基质All other constituents in a sample except for the analytesMethod blank方法空白A sample that contains all components of the matrix except the analyte.Outlier 离群值Data point whose value is much larger or smaller than the remaining data.Precision精密度An indication of the reproducibility of a measurement or resultQuantitative analysis 定量分析The determination of the amount of a substance or species present in a material. Quantitative transfer 定量转移The process of moving a sample from one container to another in a manner that ensures allmaterial is transferred.Selectivity选择性A measure of a method’s freedom from interferences as defined by the method’s selectivity coefficient. Significant figures有效数字The digits in a measured quantity, including all digits known exactly and one digit (the last) whosequantity is uncertain.Spectrophotometry分光光度法. An analytical method that involves how light interacts with a substanceStock solution储备液 A solution of known concentration from which other solutions are prepared.Titration curve滴定曲线A graph showing the progress of a titration as a function of the volume of titrant added.Validation（方法）确证，验证The process of verifying that a procedure yields acceptable results.Titration error滴定误差The determinate error in a titration due to the difference between the end point and the equivalencepoint.III. Common knowledges1.Some key journals in Analytical Chemistry: Analytical ChemistryTrends in Analytical ChemistryJournal of Chromatography AJournal of Chromatography BAnalystAnalytica Chimica ActaTALANTACritical Reviews in Analytical Chemistry Analytical and Bioanalytical ChemistryELECTROPHORESIS2. Types of articles published in scientific journals:Full Length Research PapersRapid CommunicationsReviewsShort CommunicationsDiscussions or Letters to the Editor(Some journals publish all types of articles, while others are devoted to only a single type.)3. The structure of a scientific paper:•Title•Authors (with affiliations and addresses) • Abstract (summary)• Key words•Introduction•Experimental•Results and discussion•Conclusion•Acknowledgement•References4. How to Read a Scientific Paper:Five Helpful Questions•1) WHY did they do this set of experiments?•2) HOW were the experiments actually done?•3) WHAT are the results?•4) WHAT can be concluded from the results?•5) Did they do everything correctly?5. Five-step analyzing process1) Identify and define the problem.2) Design the experimental procedure.3) Conduct an experiment and gather data.4) Analyze the experimental data.5) Report and suggestionIV. Translation exercises1. 用分散液- 液微萃取法对杀菌剂的水样品中的测定（杀真菌剂）开发的。

化学专业英语

化学专业英语化学专业英语在学习和工作中扮演着重要角色，对于化学领域的专业人士来说，掌握一定的英语能力是必不可少的。

本文将介绍化学专业英语的重要性、常用术语及学习方法。

重要性在当今全球化的社会中，英语已成为国际交流的通用语言。

化学作为一门重要的自然科学学科，与许多其他领域有着千丝万缕的联系。

因此，化学专业人士需要与不同国家和地区的同行进行交流，参与国际性的研究合作。

良好的英语能力可以帮助化学专业人士更好地理解和沟通最新的研究成果，实现信息共享和合作。

此外，化学领域的文献、期刊、会议报告等大多数都是用英语进行撰写和交流的。

若想深入研究和了解前沿化学知识，就必须具备良好的英语阅读和写作能力。

常用术语以下是化学专业中常用的一些英语术语：•Atom - 原子•Molecule - 分子•Chemical Bond - 化学键•Chemical Reaction - 化学反应•Element - 元素•Compound - 化合物•Organic Chemistry - 有机化学•Inorganic Chemistry - 无机化学•Physical Chemistry - 物理化学•Analytical Chemistry - 分析化学•Biochemistry - 生物化学•Polymer - 聚合物熟练掌握这些术语对于化学专业学习和工作至关重要。

学习方法要提高化学专业英语水平，以下是一些建议的学习方法：1.多读英文文献：阅读化学领域的英文期刊、论文或专业书籍，可以帮助提升英语阅读能力和专业术语的熟练掌握。

2.参加英语课程：参加专门针对化学专业英语的培训班或课程，系统学习化学领域的英语知识。

3.与外国同行交流：积极参与国际会议、学术交流活动，与外国同行进行交流，提高英语口语表达能力。

4.写作练习：多写化学相关的英文论文摘要、实验报告等，提升英语写作技巧。

5.背单词：每天坚持背诵一些化学专业英语词汇，扩大词汇量。

分析化学英文课件04 酸碱平衡Acid-Base Equilibria

Autoprotolysis
As the elemental unit of positive charge, the proton possesses a charge density which makes its independent existence in a solution extremely unlikely. Thus, in order to transform HB into B-, a proton acceptor must be present. Often as in the dissociation of acetic acid in water, this base may be the solvent(H2O) itself.
HAc = H+ + Ac- , H2O + H+ = H3O+
Combination of this two equations, HAc + H2O = H3O+ + Ac-
The protonated water molecule or hydrated proton H3O+, may be called a “hydronium ion”, but it is usually designated simply by “hydrogen ion” and often written as “H+”.
According to Arrhenius theory, acids dissociate into
hydrogen ions and anions, and bases dissociate into
hydroxide ions and cations.

化学专业英语之化学文献检索

化学专业英语之化学文献检索化学专业英语之化学文献检索THE LITERATURE MATRIX OF CHEMISTRYThe literature of chemistry and chemical technology is a rich and vast knowledge resource through which we can interact with those who have shaped our past and who are shaping our present.On accepting the invitation to write this book, I hoped to achieve the following objectives:To give the reader an appreciation of the value of the literature matrix and the vital role it has played in the progress of chemistry and technology.To delineate the scope and content of the literature matrix so that the reader can interact with and gain access to it effectively.To orient the book to students majoring in chemistry and chemical engineering and to scientists and engineers employed by the chemical industry in research arid development and in plant operations. Whereas a minority of chemists and chemical engineers affect the literature as authors, all are affected by the literature as readers and users. Reading and using the literature are not only a tradition; they are a necessity if we are to maintain scientific growth(self-education) .relate facts (idea seeking), and establish background information for new research programs (insurance against repeating what has already been done).Too many graduates leave the educational environment with the belief that learning goes on in academic buildings and nowhere else. To limit thinking within the bounds of formaleducation and training makes us artisans and our science an art. and courts technical obsolescence within a decade1.The chemical literature offers professional chemists and chemical engineers an opportunity for continuous .lifelong self-education. Ideally .every course in science and engineering curriculums should train students to utilize the literature for self-education. The student should be taught not only segmented disciplines, but also how to learn science and technology that is changing rapidly in directions that cannot be anticipated easily.The amount of information to be taught has increased so much that most professor? find little time to teach the literature.Furthermore ,chemistry and chemical technology are increasingly segmented into new disciplines and subdisciplmes .such as polymer chemistry, material science, and environmental science. The need to teach electronics and computer science in addition to the new disciplines have forced the elimination of courses in literature, history, and philosophy of chemistry from the majority of curriculums. Of the approximately 2000 colleges and universities that grant degrees in chemistry, only a few offer courses in the literature of chemistry and still fewer m the history and philosophy of chemistry. Paradoxically when the chemical literature was relatively small, the literature and history of chemistry were considered to be important components of the curriculum, and a high percentage of colleges and universities had courses in those subjects. Many textbooks written for students of the late nineteenth and the first three decades of the twentieth century emphasized the literature. and history of chemistry. Unfortunately, this is no longer the case.f he twentieth century has been a period of rapid growth in the chemical industry and in governmental laboratories, inresearch and development funding by both the chemical industry and the federal government, and in the numbers of chemists and chemical engineers. The result has been a correspondingly rapid growth of the literature in a multitude offragmented disciplines and subdisciplines. The size, growth, and complexity of the literature became such in the twentieth century, and particularly since 1940, that a multitude of information services were created and a number of guide books were written to aid the user of the literature. One of the best known of these was A Guide t& the Literature of Chemistry by E.J. Crane and A.M. Patterson, published in 1927 by John Wiley &. Sons. This book enjoyed wide use as a text for courses in the literature of chemistry, as did the second edition (1957) by Crane, Patterson, and E.B. Marr, Two other highly regarded and much used texts were Chemical Publications--Their Nature and Use by M. G. Mellon (1928, 1940, and 1948; McGraw-Hill) and Library Guide for the Chemist by B. A. Soule (1938, McGraw-Hill).Another response to the size, growth and complexity, of the literature was the appearance of a new specialist, the chemical information scientist, and a new subdiscipline of chemistry, chemical information science—now a well-established career for thousands of chemists. Although the activities engaged in by these chemists are taught in colleges and universities, the courses are not a part of the chemistry curriculum, nor do they constitute a curriculum for chemical information science2. Chemical information scientists edit and write technical material, translate, index, abstract, search the literature, design information systems rand relate the 'literature to the needs of anenvironment. As computers became increasingly important in processing information, chemical information scientists played an important role in employing this new tool for computerized information systems and services.In the nineteenth century the literature of chemistry consisted t)f personal contacts,: lectures, correspondence, books, and a few journals. As late as World War I it was-not very difficult for a chemist to read practically everything of importance published in chemistry. Thereafterit became increasingly difficult, and by the, 1930s it was impossible to read everything of importance.Today, the chemical literature consists of books .encyclopedias, treatises, data compilations, handbooks, patents, journals, abstract journals, trade literature, government publications, market research reports, and a variety of computer-based information services. Although a part of this literature matrix is discussed in books by Crane, Patterson, and Marr; Mellon; Soule; and others, the character of the literature has changed radically since these books were written. The present book includes the earlier literature, which is still of importance for retrospective searching, and the significant traditional literature and information services, which are essential for maintaining current awareness and for retrospective searching.Books, encyclopedias, treatises, data compilations, etc., are the vade mecum of students in all subject areas, especially in science and engineering. These are the subjects covered in Chapters 1, 2, and 3. Books are the major resource utilized in the educational process, and one who has not learned how to use school and public libraries can hardly claim to be educated. The books one acquires during the academic years are but a drop inthe ocean of literature, and this drop evaporates rather quickly into obsolescence. Throughout one's professional career it is important to gain familiarity with a large number of books, encyclopedias, treatises, etc. , and with sources that give information about new books. The survey of books in Chapter 1 is neither definitive nor all-inclusive; it is, however, highly selective, based on my own use of many of the books listed or on the evaluations of others. Year of publication is not given for every book because many undergo periodic revision; the reader should seek the latest edition.Familiarity with treatises and encyclopedias, such as those listed and discussed in Chapter 2, is a sine qua non for all practicing chemists and engineers. Organic chemists cut their teeth on Beilstein and Houben-Weyl, and inorganic chemists on Gmelin. The most important general reference book today is the Kirk—Othmer Encyclopedia of Chemical Technology. Considerable searching and learning time is saved by knowing and consult-ing these encyclopedias and treatises. Like most other tools of chemistry .expertise comes with frequent use.Every chemist and chemical engineer should have a personal copy of a single-volume handbook, such as Lange's, Perry's, or CRC's, and should be aware of and frequently consult comprehensive works, such as Landolt-Bornstein, International Critical Tables, and the special data compilers of critical data discussed in Chapter 3.Patents constitute an integral resource of the chemical literature. They have a unique literary form, written to satisfy legal requirements, and very unlike that used for reports or journal literature. Most important, they are an essential and useful source of chemical technology, and they play a critical role in theconduct of research and development in the chemical industry. The number of abstracts of basic patents published in Chemical Abstracts, which very recently has been in excess of 60000 per year, gives an indication of the size of this literature. Chapter 4 discusses patents as a resource and how to use them. Journal literature has been the fastest growing segment of the chemical literature. Whereas books, encyclopedias, and treatises discuss the past events of chemistry, journals record the current happenings. Journals came into existence in the seventeenth century as a better and faster communication medium than letter, pamphlet, or book, and slowly evolved into the dominant medium for reporting and communicating activities in。

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