化学科技论文的阅读与翻译
化学论文翻译 - 英文原文+汉语翻译
School of Medical Engineering, Hefei University of Technology, Hefei 230009, China Received April 29, 2013; accepted June 23, 2013; published online August 21, 2013
Polo-like kinase 1 (Plk1), a member of a family of serine/threonine kinases, is an attractive target for the development of anticancer drugs because it is involved in the regulation of cell-cycle progression and cytokinesis. This kinase provides two pockets for developing Plk1 inhibitors: the N-terminal catalytic domain (NCD) and the polo-box domain (PBD). For both of the two pockets, some natural products were identified as Plk1 inhibitors and some synthetic Plk1 inhibitors were developed by mimicking ATP and phosphopeptides, natural products binding to NCD and PBD respectively. This article not only reviews the progression of Plk1 inhibitors binding to these two pockets, but also discusses diversity evolution and jump in the process of drug development using Plk1 inhibitors as examples and how they impact on drug design and pharmacophore modeling. diversity evolution, diversity jump, Polo-like kinase 1, ATP mimics, natural product
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。
化学的作文word
化学的作文word英文回答：Chemistry is the study of the properties, composition, and behavior of matter. It encompasses a wide range of topics, including the structure of atoms, the bonding between atoms, the properties of molecules, the reactions between substances, and the applications of chemistry in various fields.Chemistry is often divided into several subfields, including analytical chemistry, inorganic chemistry, organic chemistry, physical chemistry, and biochemistry. Analytical chemistry deals with the identification and quantification of substances, while inorganic chemistry focuses on the properties and reactions of inorganic compounds. Organic chemistry involves the study of compounds that contain carbon, while physical chemistry deals with the physical properties and behavior of matter. Biochemistry is the study of the chemical processes thatoccur in living organisms.Chemistry is a fundamental science that has applications in many fields, including medicine, agriculture, materials science, and environmental science. For example, chemistry is used to develop new drugs, fertilizers, and materials, and to monitor and mitigate environmental pollution.Chemistry is a complex and challenging subject, but it can also be very rewarding. By understanding the basic principles of chemistry, students can gain a deeper understanding of the world around them and develop the skills necessary to solve real-world problems.中文回答：化学是一门研究物质的性质、组成和行为的学科。
化学征文作文万能模板范文
化学征文作文万能模板范文英文回答：Introduction。
Chemistry, the study of matter and its properties, is a fundamental science that underlies many aspects of our modern world. From the development of new materials to the understanding of biological processes, chemistry plays a vital role in our daily lives. In this essay, we will explore the vast scope of chemistry, discuss its historical developments, and highlight its importance in various fields.Historical Development of Chemistry。
The roots of chemistry can be traced back to ancient times, where alchemists sought to transform base metalsinto gold and discover the elixir of life. While their methods were often based on superstition and mysticism,their experiments laid the foundation for modern chemistry. In the 17th and 18th centuries, scientists such as Antoine Lavoisier and Joseph Priestley made significant contributions to the field, establishing the law of conservation of mass and discovering new elements. The 19th century witnessed the development of the periodic table by Dmitri Mendeleev, which revolutionized our understanding of chemical elements.Branches of Chemistry。
化学文献翻译
化学文献翻译在化学中，尤其是有机化学领域，合成化合物是一项重要的研究任务。
这种合成过程往往需要引入不同的官能团，以改变化合物的性质。
在过去的几十年里，已经开发出了许多有效的方法来合成多种化合物。
然而，对于有机化学家来说，找到一种选择性高、底碳经济的方法仍然是一项巨大的挑战。
现有的一种合成策略是利用种子催化剂进行合成。
种子催化剂是一种通过与底物分子结合并催化其反应的分子。
通过调节种子催化剂的结构，可以实现对目标化合物的高选择性合成。
然而，当前的合成方法存在一些限制，如混合性较差、反应时间较长等。
因此，寻找一种更高效、更可控的合成方法是非常重要的。
在本研究中，我们开发了一种新的种子催化剂，用于选择性合成异丙基苯。
我们发现这种催化剂具有良好的催化活性和选择性，可以在室温下将底物转化为所需的产物。
这是一种底碳经济的合成方法，可以节约资源并减少对环境的污染。
我们在实验过程中优化了反应条件，并通过核磁共振、气相色谱和质谱等技术对反应产物进行了表征。
结果表明，合成的异丙基苯纯度高、产率高，并且没有明显的副反应产物。
通过进一步的实验和分析，我们发现催化剂结构的某些特定部分对于反应的效果至关重要。
这些结构细节可为未来优化反应条件提供指导。
在总结中，我们成功地合成了异丙基苯，这是一种具有广泛应用前景的化合物。
我们的结果证明，利用种子催化剂进行选择性合成是一种有效的方法，可以用于合成其他化合物。
尽管我们取得了一些进展，仍然有许多问题需要解决。
其中一个问题是如何使用更底碳的底物，以减少对环境的负面影响。
还有许多其他的挑战需要克服，例如寻找更高效的催化剂和进一步改善反应条件。
总的来说，我们的研究为合成化合物提供了一种新的方法，并为今后的研究提供了基础。
我们相信，在不久的将来，我们将能够开发出更高效、更可控的合成方法，为化学领域带来更多的突破。
论文翻译
面临问题和挑战可充电锂电池在对便携式电子设备需求不断的情况下，可充电固态电池的的技术进步也在逐步推进。
锂电池就是这个大系统下的一个选择，它能提供高密度能量，能设计得轻便，还具有比其他类似的电池更长的使用寿命。
我们将展示对锂充电电池的发展做一个简单的历史回顾，突出可持续研究战略和讨论保持关于持续合成的表征、电化学性能和这些系统安全所面临的挑战。
可充电锂电池是我们这个通信设备便携式、娱乐化、计算机化、信息量极大的今天的一个重要组成。
不管全球范围内电池销量增长的有多么令人震惊，基本电池。
虽然在世界范围内电池销售的发展让人印象深刻，但电池科技的缓慢发展却经常为人诟病。
无论对于哪方面的电池技术，发展缓慢都是不可改变的事实。
（例如，镍镉，镍氢或锂离子）。
当然，相比之下，储能大小的发展已经不能满足计算机行业的发展速度（摩尔定律预测内存容量每两年翻一番），但在过去十年化学与工程在新兴科技如Ni–MeH电池和Li-ion 电池方面有了极其壮丽的发展。
现在这些正在逐步取代众所周知的镍镉电池。
一个电池提供所需的电压和容量，分别是由几个电化学电池串联和/或并联组成的。
每个电池由正负两电极构成（两电极均由化学反应产生）含游离盐的电解质溶液电离，使离子在两个电极之间转移。
一旦这些电极外部连接，化学反应将会在两个电极连续进行，从而释放出电子和产生电流提供给用电器。
电能大小表示单位质量（W h kg–1)）或单位体积（W h l–1），电池能够提供的电池电势（V）和电容（A h kg–1），这两者是直接链接到化学系统中。
在各种现有的技术中（图1），锂基电池--由于他们的高能量密度和设计的灵活性，目前优于其他系统，并且便携式电池1占全球销售值的63％。
这就解释了为什么它们在基础研究和应用水平上最受关注。
锂离子电池研究的发展历史个人认为，在评估的锂离子电池技术的研究和未来的挑战的现状之前，我们先提出它在过去30年发展的一个历史简述。
一篇化学文献的翻译
英语原文Highly Efficient One-Pot Three-Component Mannich Reaction in Water Catalyzed by Heteropoly AcidsAbstractHeteropoly acids efficiently catalyzed the one-pot, three-component Carrying out organic reactions in water has become highly desirable in recent years to meet environmental considerations.1The use of water as a sole medium for organic reactions would greatly contribute to the development of environmentally friendly processes. Indeed, industry prefers to use water as a solvent rather than toxic organic solvents. In this context, in recent years, much attention has been focused on Lewis acid catalyzed organic reactions in water.Heteropoly acids (HPAs) are environmentally benign and economically feasible solid catalysts that offer several advantages.2Therefore, organic reactions that exploit heteropoly acid catalysts in water could prove ideal for industrial synthetic organic chemistry applications, provided that the catalysts show high catalytic activity in water.Mannich reactions are among the most important carbon−carbon bondforming reactions in organic synthesis.3They provide β−amino carbonyl compounds, which are important synthetic intermediates for various pharmaceuticals and natural products.4The increasing popularity of the Mannich reaction has been fueled by the ubiquitous nature of nitrogen-containing compounds in drugs and natural products.5However, the classical Mannich reaction is plagued by a number of serious disadvantages and has limited applications. Therefore, numerous modern versions of the Mannich reaction have been developed to overcome the drawbacks of the classical method. In general, the improved methodology relies on the two-component system using preformed electrophiles, such as imines, and stable nucleophiles, such as enolates, enol ethers, and enamines.6But the preferable route is the use of a one-pot three-component strategy that allows for a wide range of structural variations. In this context, recent developments of asymmetric synthesis, using a three-component protocol, have made the Mannich reaction very valuable.7 However, despite the diverse synthetic routes so far developed for the asymmetric Mannich reaction, only a few one-pot procedures on the use of unmodified aldehydes or ketones in water have been reported in the literature. Furthermore, most of the reported Mannich reactions in water have been carried out in the presence of surfactants such as SDS. Unfortunately, normal-phase separation is difficult during workup due to the formation of emulsions because of the SDS.There is increasing interest in developing environmentally benign reactions and atom-economic catalytic processes that employ unmodified ketones, amines, and aldehydes for Mannich-type reaction in recent years. In continuation of our studies on the new variants, of one-pot, three-component Mannich-type reactions for aminoalkylation of aldehydes with different nucleophiles,9and our ongoing green organic chemistry program that uses water as a reaction medium, performs organic transformations under solvent-free conditions,10 herein we describe a mild, convenient, and simple procedure for effecting the one-pot, three-component reaction of an aldehyde, an amine, and a ketone for the preparation of β-amino carbonyl compounds in water using a heteropoly acid catalyst.Initially, the three-component Mannich reaction of 4-chlorobenzaldehyde (3.0 mmol), aniline (3.1 mmol), and the cyclohexanone (5 mmol) was examined (Scheme 1).Scheme 1. Direct Mannich Reaction Catalyzed by Heteropoly Acids in Different SolventsAs a preliminary study, several Lewis acids and solvents were screened in the model reaction. The results of extensive Lewis acid and solvent screening and optimization are shown in a table in the Supporting Information.Heteropolyacids (HPAs) catalyze Mannich reactions in organic solvents such as acetonitrile, 1,2-dichloroethane, methanol, ethanol, toluene and mixtures of toluene/water and gave the desired products in low yield with the foramtion of aldol side products. Among the screened solvent systems, water was the solvent of choice, since in this solvent the Mannich-type reactions proceeded smoothly and afforded the desired adducts in high yields at room temperature. Consequently, we conclude that the HPAs are much more reactive in water than in other organic solvents. At room temperature, the Mannich reaction proceeded to completion affording the Mannich adduct in good to excellent yield and relatively good diastereoselectivity. Addition of surfactants such as sodium dodecyl sulfate (SDS) or cetyltrimethylammonium bromide (CTAB) was not effective, and they did not improve diastereoselectivity. The reaction in pure water without using any catalyst gave a low yield of the product. Furthermore, we were excited to find that only 0.12 mol % of the catalyst gave good yields at room temperature. In the some cases, even 0.06 mol % of HPA was sufficient for the completion of the reaction. Furthermore, simple workup in water opened the route for an entirely green highly efficient one-pot Mannich reaction in water. In addition, H3PMo12O40has been compared with H3PW12O40, and we found the same results for both heteropoly acids in this reaction in water.Encouraged by the remarkable results obtained with the above reaction conditions, and in order to show the generality and scope of this new protocol, we used various aldehydes and amines and the results. T able 2 clearly demonstrates that HPAs are excellent catalysts for Mannich reactions in water. Thus, a variety of aromatic aldehydes, including electron-withdrawing and electron-donating groups, were tested using our new method in water in the presence of H3PW12O40or H3PMo12O40. The results are shown in T able 2. Generally, excellent yields of α-amino ketones were obtained for a variety of aldehydes including those bearing an electron-withdrawing group. Furthermore, several electron-rich aromatic aldehydes led to the desired products in good yield. However, under the same reaction conditions aliphatic aldehydes, such as isobutyaldehyde, gave a mixture, due to enamine formation; the desired product was obtained in low yield (Table 2, entry 22). The scope of our method was extended to other amines. In the case of amines having an electron-donating group, such as 4-isopropylaniline, the corresponding amino ketones were obtained in good yields. Furthermore, amines with electron-withdrawing groups, such as 4-chloroaniline and 3,4-dichloroaniline, gave the desired product in good yields.The high yield, simple reaction protocol, and originality of this novel process prompted us to use other ketones under these conditions (Table 1). Thus, the three-component coupling reactions were carried out with acyclic ketones such as 2-butanone and acetophenone. The expected products were obtained in moderate yields under these conditions. Acyclic ketones were less reactive than cyclohexanone and needed much more catalyst to afford the desiredproducts (T able 1). Table 1. HPA-Catalyzed Three-Component MannichReaction a Table 2. One-Pot, Three-Component Direct MannichReaction aaldehydes by the use of proline, HBF4, and dibutyltin dimethoxide.Scheme 2. Aldole and Mannich Reaction in Water翻译稿杂多酸高效催化三组分共混曼尼希反应Najmodin艾则孜，LallehT orkiyan，穆罕默德R •赛迪*谢里夫理工大学化学系，PO 11465-9516箱，伊朗，德黑兰11365ORG 。
加速器驱动热中子反应堆-科技论文翻译-汪键-SA14214058
加速器驱动热中子反应堆摘要在本片文章中，我们将来讨论用加速器驱动热核反应堆来同时生产能量和同位素的可行性。
我们讨论的是加速器驱动的热钍反应堆。
本研究表明，这样的系统可以在加速结束后产生2-15倍的能量。
它所获得的能量取决于燃料燃烧的速度。
例如，一个每年燃烧9%的钍燃料的慢中子反应堆，中子损失为4%，具有70%-79%的发电效率。
中子损失更多的是在反应堆本身而不是反应堆材料。
反应堆效率取决于每Gev加速器能量所产生的中子，目前并未准确给出。
在日常的生产使用中，这种类型的反应堆也应该是相对安全的。
1、背景介绍令人感觉奇怪的是，大自然中的天然反应堆的出现比人类制造出第一座反应堆要早的多（Cowan，1976）。
他们通常发生在具有丰富的存储铀能源的地方。
在这些反应堆里，会一直产生自持的链式核反应知道U-235不足以满足当前反应所需要的自持条件时才会结束。
在非洲Oklo地区发现了15座这样的反应堆，它们持续了50-100万年。
在燃料消耗完之前，有一半的U-235被燃烧殆尽。
在第二次世界大战期间，第一座人工反应堆出现。
20世纪下半叶快中子反应堆发展极为迅速。
而加速器驱动反应堆（ADNR）是最新出现的概念，是一种在未来在核能源的发展上具有革命性的一种堆型。
核裂变反应堆是一种填充了了核燃料和中子诱发链式反应的一种装置，如果有一个外部中子源，反应堆会一直保持稳态运行，知道产生的中子少于消耗的中子。
在当前反应堆中，有一个参数我们称之为临界参数必须等于1。
在本文中，我们定义了临界中子的数量的比率产生的裂变核内组件数量多的中子吸收。
有些作者把临界值定义为这一代在反应堆中产生的中子数除以上一代中子产生数。
根据我们的定义，如果一个反应堆的临界值小于1，该反应堆将停堆。
如果反应堆临界值大于1，反应堆中的中子通量将开始增长，并且在反应堆中的中子通量将会一直增长知道其变为亚临界状态，随着反应堆进入次临界状态，中子通量在短时间内会迅速减少。
化学毕业论文英文献及翻译
化学毕业论文英文献及翻译负载水杨醛1,3丙二酸二异丙酯二亚胺(BSPDI)的活性炭分离富集食物样品中某些重金属——火焰原子吸收光谱法测定摘要:在已有的报导中有一种灵敏而又简单的方法，能同时富集实际样品3+3+2+2+2+2+中的Cr、Fe、Cu、Ni、Co和Zn。
在该方法的基础上，将BSPDI 负载-1-1到活性炭上，再用8ml 2mol.L的硝酸的丙酮溶液或10ml 4mol.L的硝酸溶液对改性的活性炭洗提后吸附金属。
经调查分析，包括采样体积和PH值都是影响结果的分析参数。
检测分析物的残留物上的基质离子的影响，通常分析物的回收率是能测定的。
该方法已成功地应用于对一些食物样品中某些金属的内容评价。
1、介绍在包括自然水域的环境样品中，对微量金属的测定是为了表明生态污染程度和有关健康问题。
通常先确定所分离的元素是样品的主要组成部分，而后才涉及到时对这些微量组成的分离富集。
对微量金属的分析存在于各种样品中，像自然界的废水，泥沙和一些分析技术能直接测定的组织。
比如由于其他离子的基质影响、样品中金属离子的浓度转低和选择性低灵敏性低的分析技术而使原子吸收方法就不能用来真接测定。
事实上，固相萃取是一个强大的工具，能分离富集各种无机有机分析物。
在技术上它有风几个优点:固相稳定性好，可重复性好，能达到较高的富集效果，分离富集的动力条件温和，无需特殊的有机溶剂，试剂消耗低产生费用小。
几个选择性的用物理负载或化学绑定的鳌合剂等不同载体的固相萃取物已经准备好，例如:硅胶，活性炭，涂SDS氧化铝，改性硅藻土载体，标记离子聚合物，XAD-2000安伯来树脂。
活性炭是一种广泛应用在水、高纯度物质、蔬菜样品等分析物的多元微量富集的收集物。
一般使用活性炭对金属富集的方法是通过简单调整水溶液的PH到适当的值后与金属进行螯合，此过程的缺点是它需要一系列的络合步骤，因此，最近提出使用螯合活性炭。
金属螯合物可以提供高选择性和高富集效果，寻找这样一种分离富集技术。
关于化学的科技英语作文
关于化学的科技英语作文英文：Chemistry is a fascinating subject that has brought about numerous technological advancements in our world. From the creation of synthetic materials to the development of life-saving drugs, chemistry plays a vital role in our everyday lives.One example of how chemistry has impacted our world is through the development of plastics. Plastics are synthetic materials that are used in a wide range of products, from packaging to construction materials. Without the advancements in chemistry, we would not have the convenience and durability that plastics provide.Another example is the development of pharmaceuticals. Chemistry has allowed us to create drugs that can treat and cure diseases, saving countless lives. For example, the development of antibiotics has revolutionized the medicalfield, allowing us to treat bacterial infections that were once fatal.In addition to these practical applications, chemistry has also helped us better understand the world around us. Through the study of chemical reactions and properties, we have gained a deeper understanding of the natural world and how it functions.Overall, chemistry has had a profound impact on our world, from the products we use every day to the medicines that save our lives. Its continued advancements will undoubtedly lead to even more technological breakthroughs in the future.中文：化学是一个迷人的学科，它在我们的世界中带来了许多技术进步。
化学论文范文
化学论文范文
《化学领域中的新进展》
化学是一门研究物质的组成、性质、结构和变化规律的科学，它的研究范围涉及到从微观到宏观的各种物质及其性质的研究。
在这个快速发展的时代，化学领域一直都在不断地有新的进展。
近年来，化学领域中的新进展在很大程度上得益于科学技术的发展。
随着先进仪器设备的不断更新和改进，人们对于物质的研究能够更加深入和全面。
新型的实验方法和技术工具的应用为化学领域的发展提供了更加丰富的数据和信息，从而推动了新的研究成果的产生。
另外，化学领域中的新进展也离不开科学家们的不断努力和探索。
他们在有限资源和条件下，依然能够不断提出新的理论和观点，推动化学领域的发展。
在新材料的研发、环境污染物的治理、生物化学的研究等方面，都取得了一系列具有重大意义的成果。
此外，化学领域的新进展还在很大程度上受益于不同学科间的交叉渗透。
在人们对于物质的认知不断提升的过程中，物理学、生物学、工程学等与化学相关的学科也在不断地为化学研究提供新的思路和方法。
不同学科间的交叉融合和合作，为化学领域的新进展注入了新的活力。
在未来，化学领域中的新进展将会继续不断涌现。
随着科技的
不断进步和人们对于物质认知的深入，相信化学领域将会有更多的新发现和新突破，为人类社会的发展做出更大的贡献。
毕业设计论文化学系毕业论文外文文献翻译中英文
毕业设计论文化学系毕业论文外文文献翻译中英文英文文献及翻译A chemical compound that is contained in the hands of the problemsfor exampleCatalytic asymmetric carbon-carbon bond formation is one of the most active research areas in organic synthesis In this field the application of chiral ligands in enantioselective addition of diethylzinc to aldehydes has attracted much attention lots of ligands such as chiral amino alcohols amino thiols piperazines quaternary ammonium salts 12-diols oxazaborolidines and transition metal complex with chiral ligands have been empolyed in the asymmetric addition of diethylzinc to aldehydes In this dissertation we report some new chiral ligands and their application in enantioselective addition of diethylzinc to aldehydes1 Synthesis and application of chiral ligands containing sulfur atomSeveral a-hydroxy acids were prepared using the literature method with modifications from the corresponding amino acids valine leucine and phenylalanine Improved yields were obtained by slowly simultaneous addition of three fold excess of sodium nitrite and 1 tnolL H2SO4 In the preparation of a-hydroxy acid methyl esters from a-hydroxy acids following the procedure described by Vigneron a low yield 45 was obtained It was found that much better results yield 82 couldbe obtained by esterifying a-hydroxy acids with methanol-thionyl chlorideThe first attempt to convert S -2-hydroxy-3-methylbutanoic acid methyl ester to the corresponding R-11-diphenyl-2-mercapto-3-methyl-l-butanol is as the following S-2-Hydroxy-3-methylbutanoic acid methyl ester was treated with excess of phenylmagnesium bromide to give S -11-diphenyl-3-methyl-12-butanediol which was then mesylated to obtain S -11-diphenyl-3-methyl-2-methanesulfonyloxy -l-butanol Unfortunately conversion of S-11-diphenyl-3-methyl-2- methanesulfonyloxy -l-butanol to the corresponding thioester by reacting with potassium thioacetate under Sn2 reaction conditions can be achieved neither in DMF at 20-60 nor in refluxing toluene in the presence of 18-crown-6 as catalyst When S -1ll-diphenyl-3-methyl-2- methane sulfonyloxy -l-butanol was refluxed with thioacetic acid in pyridine an optical active epoxide R-22-diphenyl -3-isopropyloxirane was obtained Then we tried to convert S -11-diphenyl-3-methyl-l2-butanediol to the thioester by reacting with PPh3 DEAD and thioacetic acid the Mitsunobu reaction but we failed either probably due to the steric hindrance around the reaction centerThe actually successful synthesis is as described below a-hydroxy acid methyl esters was mesylated and treated with KSCOCH3 in DMF to give thioester this was than treated with phenyl magnesium bromide to gave the target compound B-mercaptoalcohols The enantiomeric excesses ofp-mercaptoalcohols can be determined by 1H NMR as their S -mandeloyl derivatives S -2-amino-3-phenylpropane-l-thiol hydrochloride was synthesized from L-Phenylalanine L-Phenylalanine was reduced to the amino alcohol S -2-amino-3-phenylpropanol Protection of the amino group using tert-butyl pyrocarbonate gave S -2-tert-butoxycarbonylamino-3-phenylpropane-l-ol which was then O-mesylated to give S -2-tert-butoxycarbonylamino-3-phenylpropyl methanesulfonate The mesylate was treated with potassium thioacetate in DMF to give l-acetylthio-2-tert-butoxycarbonylamino-3-phenylpropane The acetyl group was then removed by treating with ammonia in alcohol to gave S -2-tert-butoxycarbonylamino-3-phenyl-propane-l-thiol which was then deprotected with hydrochloric acid to give the desired S-2-amino-3-phenylpropane-1-thiol hydrochlorideThe enantioselective addition of diethylzinc to aldehydes promoted by these sulfur containing chiral ligands produce secondary alcohols in 65-79 Synthesis and application of chiral aminophenolsThree substituted prolinols were prepared from the naturally-occurring L-proline using reported method with modifications And the chiral aminophenols were obtained by heating these prolinols with excess of salicylaldehyde in benzene at refluxThe results of enantioselective adBelow us an illustration forexampleN-Heterocyclic carbenes and L-Azetidine-2-carboxylicacidN-Heterocyclic carbenesN-Heterocyclic carbenes have becomeuniversal ligands in organometallic and inorganic coordination chemistry They not only bind to any transition metal with low or high oxidation states but also to main group elements such as beryllium sulfur and iodine Because of their specific coordination chemistry N-heterocyclic carbenes both stabilize and activate metal centers in quite different key catalytic steps of organic syntheses for example C-H activation C-C C-H C-O and C-N bond formation There is now ample evidence that in the new generation of organometallic catalysts the established ligand class of organophosphanes will be supplemented and in part replaced byN-heterocyclic carbenes Over the past few years this chemistry has become the field of vivid scientific competition and yielded previously unexpected successes in key areas of homogeneous catalysis From the work in numerous academic laboratories and in industry a revolutionary turningpoint in oraganometallic catalysis is emergingIn this thesis Palladium Ⅱ acetate and NN"-bis- 26-diisopropylphenyl dihydro- imidazolium chloride 1 2 mol were used to catalyze the carbonylative coupling of aryl diazonium tetrafluoroborate salts and aryl boronic acids to form aryl ketones Optimal conditions include carbon monoxide 1 atm in 14-dioxane at 100℃ for 5 h Yields for unsymmetrical aryl ketones ranged from 76 to 90 for isolated materials with only minor amounts of biaryl coupling product observed 2-12 THF as solvent gave mixtures of products 14-Dioxane proved to be the superior solvent giving higher yieldsof ketone product together with less biphenyl formation At room temperature and at 0℃ with 1 atm CO biphenyl became the major product Electron-rich diazonium ion substrates gave a reduced yield with increased production of biaryl product Electron-deficient diazonium ions were even better forming ketones in higher yields with less biaryl by-product formed 2-Naphthyldiazonium salt also proved to be an effective substrate givingketones in the excellent range Base on above palladium NHC catalysts aryl diazonium tetrafluoroborates have been coupled with arylboron compounds carbon monoxide and ammonia to give aryl amides in high yields A saturated yV-heterocyclic carbene NHC ligand H2lPr 1 was used with palladium II acetate to give the active catalyst The optimal conditions with 2mol palladium-NHC catalyst were applied with various organoboron compounds and three aryl diazonium tetrafluoroborates to give numerous aryl amides in high yield using pressurized CO in a THF solution saturated with ammonia Factors that affect the distribution of the reaction products have been identified and a mechanism is proposed for this novel four-component coupling reactionNHC-metal complexes are commonly formed from an imidazolium salt using strong base Deprotonation occurs at C2 to give a stable carbene that adds to form a a-complex with the metal Crystals were obtained from the reaction of imidazolium chloride with sodium t- butoxide Nal and palladium II acetate giving a dimeric palladium II iodide NHC complex The structure adopts a flat 4-memberedring u2 -bridged arrangement as seen in a related dehydro NHC complex formed with base We were pleased to find that chloride treated with palladium II acetate without adding base or halide in THF also produced suitable crystals for X-ray anaysis In contrast to the diiodide the palladium-carbenes are now twisted out of plane adopting a non-planar 4-ring core The borylation of aryldiazonium tetrafluoroborates with bis pinacolatoborane was optimized using various NHC ligand complexes formed in situ without adding base NN"-Bis 26-diisopropylphenyl-45-dihydroimidazolium 1 used with palladium acetate in THF proved optimal giving borylated product in 79 isolated yield without forming of bi-aryl side product With K2CO3 and ligand 1 a significant amount of biaryl product 24 was again seen The characterization of the palladium chloride complex by X-ray chrastallography deL-Azetidine-2-carboxylic acidL-Azetidine-2-carboxylic acid also named S -Azetidine-2-carboxylic acid commonly named L-Aze was first isolated in 1955 by Fowden from Convallaria majalis and was the first known example of naturally occurring azetidine As a constrained amino acid S -Azetidine-2-carboxylic acid has found many applications in the modification of peptides conformations and in the area of asymmetric synthesis which include its use in the asymmetric reduction of ketones Michael additions cyclopropanations and Diels-Alder reactions In this dissertation five ways for synthesize S-Azetidine-2-carboxylic acid were studied After comparing all methods theway using L-Aspartic acid as original material for synthesize S-Azetidine-2-carboxylic acid was considered more feasible All mechanisms of the way"s reaction have also been studied At last the application and foreground of S -Azetidine-2-carboxylic acid were viewed The structures of the synthetic products were characterized by ThermalGravity-Differential Thermal Analysis TG-DTA Infrared Spectroscopy IR Mass Spectra MS and 1H Nuclear Magnetic Resonance 1H-NMR Results showed that the structures and performances of the products conformed to the anticipation the yield of each reaction was more than 70 These can conclude that the way using L-Aspartie acid as original material for synthesize S -Azetidine-2-carboxylic acid is practical and effective杂环化合物生成中包含手性等问题如催化形成不对称碳碳键在有机合成中是一个非常活跃的领域在这个领域中利用手性配体诱导的二乙基锌和醛的不对称加成引起化学家的广泛关注许多手性配体如手性氨基醇手性氨基硫醇手性哌嗪手性四季铵盐手性二醇手性恶唑硼烷和过渡金属与手性配体的配合物等被应用于二乙基锌对醛的不对称加成中在本论文中我们报道了一些新型的手性配体的合成及它们应用于二乙基锌对醛的不对称加成的结果1含硫手性配体的合成和应用首先从氨基酸缬氨酸亮氨酸苯丙氨酸出发按照文献合成α-羟基酸并发现用三倍量的亚硝酸钠和稀硫酸同时滴加进行反应能适当提高反应的产率而根据Vigneron等人报道的的方法用浓盐酸催化从α-羟基酸合成α-羟基酸甲酯时只能获得较低的产率改用甲醇-二氯亚砜的酯化方法时能提高该步骤的产率从 S -3-甲基-2-羟基丁酸甲酯合成 R -3-甲基-11-二苯基-2-巯基-1-丁醇经过了以下的尝试 S -3-甲基-2-羟基丁酸甲酯和过量的格氏试剂反应得到 S -3-甲基-11-二苯基-12-丁二醇进行甲磺酰化时位阻较小的羟基被磺酰化生成 S -3-甲基-11-二苯基-2- 甲磺酰氧基 -1-丁醇但无论将 S -3-甲基-11-二苯基-2- 甲磺酰氧基 -1-丁醇和硫代乙酸钾在DMF中反应 20～60℃还是在甲苯中加入18-冠-6作为催化剂加热回流都不能得到目标产物当其与硫代乙酸在吡啶中回流时得到的不是目标产物而是手性环氧化合物 R -3-异丙基-22-二苯基氧杂环丙烷从化合物 S -3-甲基-11-二苯基-12-丁二醇通过Mitsunobu反应合成硫代酯也未获得成功这可能是由于在反应中心处的位阻较大造成的几奥斯塑手村犯体的合成裁其在不对称奋成中肠左用摘要成功合成疏基醇的合成路是将a-轻基酸甲酷甲磺酞化得到相应的磺酞化产物并进行与硫代乙酸钾的亲核取代反应得到硫酷进行格氏反应后得到目标分子p一疏基醇用p一疏基醇与 R 义一一甲氧基苯乙酞氯生成的非对映体经H侧NM吸测试其甲氧基峰面积的积分求得其ee值 3一苯基一氨基丙硫醇盐酸盐从苯丙氨酸合成斗3一苯基一氨基丙醇由L一苯丙氨酸还原制备氨基保护后得到习一3一苯基一2一叔丁氧拨基氨基一1一丙醇甲磺酞化后得到习一3一苯基一2一叔丁氧拨基氨基一1一丙醇甲磺酸酷用硫代乙酸钾取代后得匀一3-苯基一2一叔丁氧拨基氨基一1一丙硫醇乙酸酷氨解得习一3一苯基一2一叔丁氧拨基氨基一1一丙硫醇用盐酸脱保护后得到目标产物扔3一苯基屯一氨基丙硫醇盐酸盐手性含硫配体诱导下的二乙基锌与醛的加成所得产物的产率为65一79值为O井92手性氨基酚的合成和应用首先从天然的L一脯氨酸从文献报道的步骤合成了三种脯氨醇这些手性氨基醇与水杨醛在苯中回流反应得到手性氨基酚手性氨基酚配体诱导下的二乙基锌与醛的加成所得产物的产率为45一98值为0一90手性二茂铁甲基氨基醇的合成和应用首先从天然氨基酸绿氨酸亮氨酸苯丙氨酸和脯氨酸合成相应的氨基醇这些氨基醇与二茂铁甲醛反应生成的NO一缩醛经硼氢化钠还原得到手性二茂铁甲基氨基醇手性二茂铁甲基氨基醇配体诱导下的二乙基锌与醛的加成所得产物的产率为66一97下面我们举例说明一下例如含氮杂环卡宾和L-氮杂环丁烷-2-羧酸含氮杂环卡宾含氮杂环卡宾已广泛应用于有机金属化学和无机配合物化学领域中它们不仅可以很好地与任何氧化态的过渡金属络合还可以与主族元素铍硫等形成配合物由于含氮杂环卡宾不但使金属中心稳定而且还可以活化此金属中心使其在有机合成中例如C-H键的活化C-CC-HC-O和C-N键形成反应中有着十分重要的催化效能现有的证据充分表明在新一代有机金属催化剂中含氮杂环卡宾不但对有机膦类配体有良好的互补作用而且在有些方面取代有机膦配体成为主角近年来含氮杂环卡宾及其配合物已成为非常活跃的研究领域在均相催化这一重要学科中取得了难以想象的成功所以含氮杂环卡宾在均相有机金属催化领域的研究工作很有必要深入地进行下去本文研究了乙酸钯和NN双 26-二异丙基苯基 -45-二氢咪唑氯化物1作为催化剂催化芳基四氟硼酸重氮盐与芳基硼酸的羰基化反应合成了一系列二芳基酮并对反应条件进行了优化使反应在常温常压下进行一个大气压的一氧化碳14-二氧杂环己烷作溶剂100℃反应5h 不同芳基酮的收率达7690仅有微量的联芳烃付产物 212 反应选择性良好当采用四氢呋喃或甲苯作溶剂时得到含较多副产物的混合物由此可以证明14-二氧杂环己烷是该反应最适宜的溶剂在室温或0℃与一个大气压的一氧化碳反应联芳烃变成主产物含供电子取代基的芳基重氮盐常常给出较低收率的二芳基酮而含吸电子取代基的芳基重氮盐却给出更高收率的二芳基酮及较少量的联芳烃付产物实验证明2-萘基重氮盐具有很好的反应活性和选择性总是得到优异的反应结果在此基础上由不同的芳基四氟硼酸重氮盐与芳基硼酸一氧化碳和氨气协同作用以上述含氮杂环卡宾作配体与乙酸钯生成的高活性含氮杂环卡宾钯催化剂催化较高收率地得到了芳基酰胺优化的反应条件是使用2mol的钯-H_2IPr 1五个大气压的一氧化碳以氨气饱和的四氢呋喃作溶剂由不同的有机硼化合物与三种芳基重氮盐的四组份偶联反应同时不仅对生成的多种产物进行了定 L-氮杂环丁烷-2-羧酸L-氮杂环丁烷-2-羧酸又称 S -氮杂环丁烷-2-羧酸简称为L-Aze1955年由Fowden从植物铃兰 Convallaria majalis 中分离得到成为第一个被证实的植物中天然存在的氮杂环丁烷结构作为一种非典型的氨基酸已经发现 S -氮杂环丁烷-2-羧酸可广泛用于对多肽结构的修饰以及诸如不对称的羰基还原Michael 加成环丙烷化和Diels-Alder反应等不对称合成中的多个领域本文通过对 S -氮杂环丁烷-2-羧酸合成路线的研究综述了五种可行的合成路线及方法通过比较选用以L-天冬氨酸为初始原料合成 S -氮杂环丁烷-2-羧酸的路线即通过酯化反应活泼氢保护格氏反应内酰胺化反应还原反应氨基保护氧化反应脱保护等反应来合成 S -氮杂环丁烷-2-羧酸分析了每步反应的机理并对 S -氮杂环丁烷-2-羧酸的应用及前景给予展望通过热分析红外质谱核磁等分析手段对合成的化合物的结构进行表征结果表明所得的产物符合目标产物所合成的化合物的结构性能指标与设计的目标要求一致每步反应的收率都在70％以上可以判定以L-天冬氨酸为初始原料合成 S -氮杂环丁烷的路线方案切实可行。
化学英语论文六篇
化学英语论文六篇化学英语论文范文1英语文学的翻译过程是一项简单的翻译过程，其中英语与汉语存在着诸多文化方面的差异，假如在英语文学的翻译过程中，对彼此的文化差异重视程度不够，就会给英语文学作品的正确翻译带来障碍，直接的影响到了英语文学翻译的实效性发挥，那么反之，只有在英语文学作品翻译的过程中，充分的关注英语文化与汉语文化之间存在的详细差异，并依据存在的差异奇妙的在翻译过程中，加以恰当的翻译处理，英语文学的翻译才能更具实效性，所以在详细的翻译过程中，能否采纳正确的翻译方法处理英语文学翻译中消失的两种语言文化所带来的差异，对于英语文学翻译质量的提升具有重要的意义。
也只有在翻译的过程中正确的把握彼此的文化差异，并且恰当的处理好由于这种文化差异所带来的翻译障碍，那么其所翻译的文学作品的精确性才值得信任。
文化因素应是英语文学翻译过程中需要考虑的重要因素，在翻译中只用语言直译的方式进行翻译，即使翻译的没问题，在忽视了英汉文化差异状况下，也很难让人有一个正确的理解，所以在翻译的过程中不仅要让其直接理解语言的内容，更重要的是让其理解语言背后具有迥异文化元素的内在含义，只有突破这种文化的障碍才能真正的翻译出好的英语文学作品。
二、英语文学翻译过程中正确处理文化差异的策略1.熟悉作品的体裁，正确处理彼此之间的文化差异英语文学的翻译与其文学体裁有着亲密的联系，不同的文学体裁所具有的特点也是不相同的，针对不同体裁的独有特点，依据源语言与翻译目的语言特点之间的差异性特征，娴熟的运用这些语言存在的特征，才能真正把英语文学作品翻译的更加完善，体现出不同体裁作品的不同风格。
但是，我们也要明确文学体裁的差异不等于其文化内涵与文化元素也存在着多大的差别，如针对科技内容英语文章的翻译，其蕴含的文化元素就相对较少，因此，对这一类文章的翻译，就很少考虑文化的差异，而针对小说、话剧的英语文学体裁文章的翻译，则在详细的翻译过程中，必需要考虑其所蕴含的文化内涵，假如不考虑其文化的元素而进行翻译，其作品翻译出来肯定让人感到枯燥和乏味，而失去了作品独有的文化魅力。
介绍化学的英语作文
介绍化学的英语作文English:Chemistry is the scientific study of matter, its properties, composition, and the changes it undergoes. It plays a crucial role in our understanding of the world around us by explaining the behavior of different substances and their interactions. Chemistry is divided into several branches, including organic chemistry, inorganic chemistry, physical chemistry, and analytical chemistry, each focusing on different aspects of the subject. Organic chemistry deals with compounds containing carbon, while inorganic chemistry focuses on non-carbon-containing compounds. Physical chemistry explores the fundamental principles governing chemical reactions and the properties of substances, while analytical chemistry is concerned with the identification and quantification of substances. Chemistry has a wide range of applications in various fields such as medicine, agriculture, and technology, contributing to the development of new materials, drugs, and technologies that improve our quality of life.Translated content:化学是一门科学研究物质、其性质、组成以及其所经历的变化的学科。
中英文科技论文写作之化学术语
中英文科技论文写作之化学术语引言在科技领域，化学是一个非常重要的学科。
为了确保科技论文的准确性和可理解性，正确使用化学术语是至关重要的。
然而，对于非英语母语的作者来说，掌握化学术语的中英文翻译并正确运用在论文中可能是一个挑战。
本文将介绍一些常见的化学术语的中英文对照，帮助非英语母语作者更好地撰写科技论文。
一、化学基础词汇1.1 元素（Elements）元素是化学最基本的单位，由原子组成。
例如，氢（hydrogen）是一种元素，其化学符号为H。
以下是一些常见元素的英文名称及其化学符号：•氧（Oxygen）—— O•碳（Carbon）—— C•氮（Nitrogen）—— N•铁（Iron）—— Fe•铜（Copper）—— Cu1.2 化合物（Compounds）化合物是由不同元素按照一定比例结合而成的物质。
例如，水（water）是一种由氢和氧组成的化合物，其化学式为H2O。
以下是一些常见化合物的英文名称及其化学式：•二氧化碳（Carbon Dioxide）—— CO2•氨（Ammonia）—— NH3•氮氧化物（Nitric Oxide）—— NO•氯化钠（Sodium Chloride）—— NaCl二、基本理论和原理术语2.1 反应（Reactions）反应是指物质之间发生的化学变化过程。
以下是一些常见的反应类型的中英文对照：•氧化反应（Oxidation Reaction）•还原反应（Reduction Reaction）•酸碱中和反应（Acid-Base Neutralization Reaction）•电解反应（Electrolysis Reaction）2.2 摩尔（Moles）摩尔是一种用来计量化学物质的单位。
以下是一些与摩尔相关的术语的中英文对照：•摩尔质量（Molar Mass）•摩尔浓度（Molar Concentration）•摩尔比（Molar Ratio）2.3 平衡（Equilibrium）化学反应可以达到平衡态，意味着反应速率的正向和反向过程相互抵消，达到动态平衡。
化学专业文献翻译终结版
化学专业文献翻译终结版通过国际教育联盟化学分子中光学胺酸组对有化対映体的手性羧酸进行的分析羧酸的纯对映体是一类重要的生物分子，手性药物和手性试剂等等。
对対映体的分析经常需要昂贵的仪器或者复杂的手性受体，然而，为了发展对对映体酸性的分析的简单而可信的方法是困难的。
在这篇文献中，2,3二苯甲酰酒石酸和苯基乙醇酸的-手性识别是第一个实施通过聚合诱导发射分子轴承光学纯胺酸集团，这是一种简单合成，这种手性识别不只是被肉眼所看见，还可以被氟光度计测量。
这两种対映体酸性的荧光强度的差异通过聚合体诱导发射分子598，这种手性识别可以被应用于对手性酸対映内容的定量分析。
1介绍羧酸纯的対映体是一种重要的生物分子，手性药物手性试剂等等。
传统的対映体的分析经常需要昂贵的仪器或者复杂的手性受体，也需要时间去实践，然而，为了发展对对映体酸性的分析的简单而可信的方法是困难的。
特别的，荧光受体可以区别两种手性羧酸対映体，可以在飞速的手性试验高产出药品发现和催化剂筛选提供一个真实的时间技巧。
然而，去设计和合成极好的手性荧光受体，对羧酸対映体仍然是个挑战。
近来，一种新的有机混合物以一种惊人的聚集诱导发光（AIE）或聚合体诱导发射增大（AIEE）被发现。
这些混合物还没有在固态形式上被抑制，因此，他们不仅仅在光电子材料上表现出一种潜能，同时也将对蛋白质、DNA、有机蒸汽、肝素、金属离子、氯以高度的选择性和稳定的荧光传感器，免疫分析和乃至自组装程序的叠层，等等。
虽然手性AIE混合物关系胆甾醇基团被报道称之为透明发光的金属，调查研究工作与手性识别相联系以AIE或者ＡＩＥＥ为基础的特性还没有被报道过。
它让我们想起新异的手性荧光受体可以被制得如果一个微小粒子持有ＡＩＥ特性和另一个微小粒子有手性识别能力相关联。
这里，我们第一个报道的是ＡＩＥ混合物关系光学纯的胺酸团可以enantioselectively集合导致用一个手性羧酸的有化対映体和大量的强度荧光差异直到超过２００倍，那一个可以在有化対映体组成品的定量分析中被应用。
化学工业英文文献及译文
化学工业英文文献及译文1. 引言化学工业是现代工业中的重要部分，涉及各种化学品的生产和应用。
在化学工业的发展过程中，英文文献起着重要的作用。
本文旨在介绍化学工业英文文献的特点和相关译文的编写。
2. 化学工业英文文献的特点2.1 多样性化学工业英文文献涉及广泛的领域和专业知识。
其中包括有机化学、无机化学、物理化学、分析化学、材料科学等多个学科。
因此，了解不同领域的英文文献对于从事化学工业的人员来说非常重要。
2.2 专业性化学工业英文文献通常具有较高的专业性和技术性。
这些文献常常包含复杂的化学方程式、实验方法和数据分析等内容。
因此，阅读和理解这些文献需要读者具备一定的化学知识和实验经验。
2.3 国际性化学工业英文文献是由世界各地的科学家和研究人员撰写的。
这使得这些文献具有很强的国际性，反映了化学工业领域的前沿研究和发展动态。
对于从事国际化学工业合作和交流的人员来说，了解和掌握这些英文文献非常重要。
3. 化学工业英文文献译文的编写3.1 译前准备在进行化学工业英文文献的翻译之前，译者应充分准备，了解相关的化学知识和专业术语。
阅读英文文献中的化学方程式、实验方法和数据分析等内容，并确保自己对这些内容有清晰的理解。
3.2 译文的准确性化学工业英文文献译文要准确无误，以保持原文的科学性和技术性。
译者应尽可能使用准确的翻译术语和表达方式，确保译文的准确性。
3.3 术语的翻译化学工业英文文献中经常出现大量的专业术语，对这些术语的准确翻译是译文质量的关键。
译者应尽量使用已被广泛接受的翻译术语，避免出现模棱两可或不准确的翻译。
3.4 结构的调整化学工业英文文献的结构常常较为复杂，译者在翻译过程中可以适当调整结构，使译文更符合汉语表达习惯。
但要保持原文的主要内容和逻辑关系不变。
4. 结论化学工业英文文献对于从事化学工业的人员来说具有重要的价值。
了解化学工业英文文献的特点和编写相关译文的技巧，可以帮助读者更好地理解和应用相关的化学知识。
The Properties and Uses of Zeolites in Chemistry
The Properties and Uses of Zeolites inChemistry一、介绍化学中有很多新兴技术，在这些技术中，一些天然的矿物物质是不可或缺的原材料。
其中，低廉、易得的一种天然矿物是沸石，也被称为沸石矿。
沸石是一种多孔物质，它可以在化学反应中扮演重要的角色。
本文将对沸石的物理和化学特性以及在化学中的用途进行深入探讨。
二、物理特性沸石是一种含铝硅酸盐矿物，其化学式通常为Na2O·Al2O3·SiO2·nH2O。
在自然环境中，它通常形成为纤维状、管状、球状、板状或柱状的晶体。
沸石由许多不规则的腔隙和通道组成，它的孔径可以控制在1到5纳米之间。
这种微小的孔隙使沸石具有相当大的比表面积，一般约为500至800平方米/克。
沸石的骨架由铝氧四面体和硅氧四面体交替排列而成。
铝氧四面体和硅氧四面体之间的成键角度和原子大小之间的相互作用会改变沸石孔隙的大小和形状。
当沸石的化学成分改变时，孔隙的大小和形状也会发生变化。
沸石的孔隙几乎是球形的，它们的大小决定了吸附或分离分子的大小。
三、化学特性沸石的骨架可通过离子交换和吸附分子改变其电荷。
硅氧四面体的负电荷与铝氧四面体的正电荷些微不同，因此它们可以进行离子交换。
离子交换会改变沸石的化学性质，使其变得更加催化活性。
吸附分子的过程通常发生在孔隙中，一些沸石具有化学囚犯功能，可以去除特定的杂质分子。
沸石的化学特性主要取决于其孔隙中存在的活性位点。
这些位点可以是表面的铝、硅或水合离子，也可以是孔隙中碳或棕榈碳。
沸石可以对多种分子进行选择性吸附，利用这些位点进行分离和纯化。
四、用途沸石具有广泛的应用领域，包括催化、吸附、分离、离子交换和气体吸附等。
4.1 催化沸石具有催化作用，可用于许多化学反应。
作为催化剂，沸石可以增加反应速度和选择性。
催化反应通常发生在沸石孔隙内的表面上。
通过控制孔隙大小和形状来选择催化反应的物种，并且可以通过离子交换或添加金属离子来增强其催化性能。
化学科技英语文本解读及翻译——评《化学英语》
化学科技英语文本解读及翻译——评《化学英语》陈金云; 黄文泓【期刊名称】《《分析化学》》【年(卷),期】2019(047)012【总页数】1页(P后插2)【作者】陈金云; 黄文泓【作者单位】宜春幼儿师范高等专科学校外国语学院【正文语种】中文化学是研究物质的性质、组成、结构及其变化规律等的学科。
近年来，随着生产力水平提高，科学技术不断发展进步，化学与人们生产生活之间的联系变得越来越紧密。
在日常生活中，不难发现在人们的衣、食、住、行等方面往往都能发现化学的“影子”，如衣服、食用的食品、居住的房屋等，化学已随科学技术的发展进步逐渐深入到日常生活的方方面面。
实际上，化学不仅在人们的日常生活中扮演着重要角色，而且在医疗卫生、军事国防、环境保护等方面也起着至关重要的作用，因此解读及翻译相关化学科技英语文本确有必要。
为顺应时代发展、增强人们对生活的了解、提高相关人员的英语水平和专业知识能力，同时促进化学知识的有效传播，王帅主编了《化学英语》一书，由北京师范大学出版社于2015年3月出版发行。
该书可分为三部分，:第一部分为本书的开篇，首先详细介绍了元素周期表，旨在让读者对化学中的有关元素有一个大致了解;第二部分是本书的主体内容，包括十个章节，围绕着化学元素周期表中的元素展开论述，着重介绍一些与日常生产生活联系紧密的化学元素及其相关知识，如第I族元素、第II族元素、第VIII族元素等，这些元素与人们的生活息息相关;第三部分为附录部分，涵盖了环境科学和工程、化学工程、生物工程等方面的知识，作者引用环境科学和工程、化学工程、生物工程这几门交叉学科的有关知识理论，丰富并完善了化学英语的内容，表明化学这门学科应用的广泛性。
该著作在阐释相关知识之前，首先向读者介绍化学元素周期表，让读者先了解并掌握相关化学元素知识，然后再以化学元素周期表中的元素为中心展开论述，最后附录一些与化学相关的知识点。
由点到面，层层递进，条理性、逻辑性比较强，使读者能够更好更快地抓住相关知识点，帮助读者快速理清文章思路，促进对知识的理解。
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以Nature为例： 2008 Impact Factor
Cites in 2008 to articles published in: 2007=25365, 2006=31311, Sum: 56676
指工程技术人员为报道工程技术研究成 果而撰写的论文。这种研究成果主要是应 用国内外已有的理论来解决设计、技术、 工艺、设备、材料等具体技术问题而进行 的技术性研究。技术 性论文对工程技术的 进步和提高生产力起着直接的推动作用。 这类论文应具有技术的先进性、实用性和 科学性。
必须完整回答：
为什么研究(why)？ 怎么样研究(how)？ 结果是什么(what)？
在快速
2 不同类型论文的特征
综述性论文
这类论文应是在作者博览群书的基础上，综合介 绍、分析、评述该学科(专业)领域里国内外的研 究新成果、发展新趋势，并表明作者自己的观点， 作出学科发展的预测，提出比较中肯的建设性意 见和建议。
它与一般科技论文的主要区别在于综述型文章不 要求在研究内容上的创新性，但一篇好的综述性 文章也常常包括有某些先前未曾发表过的新资料 或新思想， 它要求撰稿人在综合分析评价已发 表过的资料基础上，提出涉及该专题在特定时期 发展 演变的规律和趋势。
2 不同类型论文的特征 快报
仍属研究性论文，写法与要求同全文一样。
不同之处在于：注重报道的新颖性和时效 性，不强调全面性。
短小精悍。
3 著名数据库及期刊简介
期刊的影响因子
影响因子(Impact Factor)是一个国际上通行 的期刊评价指标，即某期刊前两年发表的 论文在统计当年的被引用总次数除以该期 刊在前两年内发表的论文总数。该指标是 相对统计值，可克服大小期刊由于载文量 不同所带来的偏差。一般来说，影响因子 越大，其学术影响力也越大。
它的写法通常分两类：一类以汇集文献资料为主， 辅以注释，非常客观，很少评述,某些发展较活跃 的学科的综述属此类；另一类文章则着重评述， 通过回顾过去，察看现状，展望未来，提出合乎 逻辑的具有启发性的评价与建议。综述型的论文 撰写要求比较高，具有权威性，一般应具有一定 学术水平的学科带头人才能写出高水平的综述型 学术论文，此类论文往往对所讨论的专题或学科 的进一步发展起到引导作用。
特征
主题鲜明新颖，一般属热点研究方向。 引用文献全面，必须引用大量最新文献。 结构层次明确，主次分明。
2 不同类型论文的特征
研究性论文
学术性论文：指专业技术领域里的专门人员(包括 从事各类学科的专门研究人员、教学人员和生产 第一线的科技人员)提供给学术性期刊发表或向学 术会议提交的学术论文。它以报道学术研究成果 为主要内容。学术性论文反映了该学科领域最新 的、最前沿的科学技术水平和发展动向，对科学 技术事业的发展起着重要的推动作用。这类论文 应具有新的观点、新的 分析方法和新的数据和结 论，并具有科学性。从一个单位、部门、民族、 国家发表的学术论文的数量与质量，可以看出其 科学技术已经达到的水平。
查询外文期刊影响因子，可使用外文数据库Web of Science中的JCR（Journal of Reports），其 中JCR Science Edition 用于查询自然科学类期刊， JCR Social Sciences Edition用于查询人文社会 科学类期刊。
询中文期刊的影响因子，可使用中国学术期刊 （光盘版）电子杂志社和中国科学文献计量评价 中心联合推出的《中国学术期刊综合引证报告》 （万锦堃主编，科学出版社）。有需要的读者请 到图书馆咨询部查询。
The journal impact factor is a measure of the frequency with which the "average article" in a journal has been cited in a particular year. The impact factor will help you evaluate a journal's relative importance, especially when you compare it to others in the same field.
特点 （1）创造性或创新性 科技论文报道的主要研究成果应是前人所 没有的。原则上是不能重复别人的工作,可 以改进但不能照抄。没有新的观点、见解 和结论，就不成其为科技论文。通过方法、 材料、结果、理论或解析几个方面实现。
（2）理论性或学术性 理论性指一篇科技论文应具有一定的学术 价值，表现内容的专业性和系统性，有2个 方面的含义：对实验、观察或用其他方式 所得到的结果，要从一定的理论高度进行 分析和总结，形成一定的科学见解，包括 提出并解决一些有科学价值的问题；对自 己提出的科学见解或问题，要用事实和理 论进行符合逻辑的论证与分析或说明。
（3）科学性- 内容可靠，数据准确，实验 可重复。 （4）逻辑性-思路清晰，结构严谨，推导 合理和编排规范。 （5）有效性-公开发表或经同行答辩。
包括：
题目(Title)、摘要(Abstract or Summary) 、关 键词(Key words) 、前言(Introduction or Preface) 、实验或方法(Experiments or methods) 、结果与讨论(Result and Discussion) 、结论(Conclusion) 、致谢 (Acknowledgement)以及参考文献(References and Notes) 。
31
科技论文分类
2 不同类型论文的特征
3 著名数据库及期刊简介
4
论文相关知识
1 化学科技期刊论文的分类
综述性论文 Review
研究性论文 Full paper
快报 Letter
对某一领域 的研究现状 及其发展方 向进行全面
阐述
对某一研究成果 进行全面的报道 并作分析讨论
对某一研究的阶 段性成果或进展 作简单报道，重