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。
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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