中英文文献以及翻译(化工类)

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化工专业英语课文翻译

Unit 5 Basic Chemicals基本化学品我们将化学工业部门分成两类，生产量较大的部门和产量较低的部门。

在产量高的部门中，各种化学品的年产量达上万吨至几十万吨。

结果这样所用的工厂专门生产某一个单个产品。

这些工厂的连续方式进行操作，自动化程度高（计算机控制）归类于产量高的部门有硫酸，含磷化合物，含氮化合物，氯碱及其相关化合物，加上石油化学品和商品聚合物（如聚乙烯）（生产部门）。

除商品聚合物外，其它的均为重要的中间体，或基本化学品。

这些基本化学品是其他许多化学品的生产原料，其他许多基本化学品的需求量很大。

相反，产量低的部门主要从事精细化学品的生产。

单个化学品的年产量只有几十吨到几千吨。

然而，与高产量的产品相比，这些产品单位重量具有很高的价值。

通常，精细化斜坡的生产与间歇方式操作在工厂中，而且这些工厂常进行多种产品的生产。

低产量生产部门生产农用化学品，染料，药品和特种聚合物（如聚醚醚酮）。

基础化学品在化学工业中得不到支持，它们不那么引人注意（如药品），有时候利润不很高。

其利润来自于经济盛衰时难以预测的周期。

这些基本化学品不被公众注意到和直接使用，因此其重要性常得不到理解。

即使在化学工业中，其重要性也得不到足够的重视。

然而，如果没有这些基本化学品，其他工业就不复存在。

基本化学品处于原料（及那些从地下通过采矿、开采或用泵抽出来的物质）和最终产品的中间位置。

基本化学品的一个显著的特征就是它们的生产规模，每一种（基本化学品）的生产规模都相当大。

图2-1表示在1993 年美国市场上的25 中化学品。

（为了使我们了解化学品的分类与生产量有关。

）通常，基本化学品生产于那些年产量上万吨的工厂。

年产量10 万吨的工厂每小时要生产1.25 吨。

基本化学品的另一显著重要的特征是其价格。

大多数价格相当便宜。

基本化学品工业所作的工作（或任务）是找到经济的途径将原来转变为有用的中间体。

生产厂家要对它们的产品收取较高的价格几乎没有余地，因此，那些最低费用生产产品的厂家可能获得的利润最高。

化工专业英语（可编辑）

化工专业英语Volatile:挥发性的 Semipermeable membrane:半透膜 immiscible：不相混的 Debit:把….记入借方 Credit:记入贷方Electrical potential:电势 Leaching:浸提 Extraction：萃取 Direct current:直流 Instantaneous:瞬间的 Successive：连续的 Collision：碰撞 Impeller：叶轮 Wavelet analysis:微元分析 Entrainment：夹带 Breakage：破坏Attrition：磨损 Indispensable：不可缺少的 Trajectory:轨道 Acrylic：丙烯酸 Baffle：挡板 Ruffle：滋扰 Discharge:释放 circulation flow:环流attrition：磨损 nucleation：成核 Catalytic：催化 frequency：频率shutter：快门 inertia：惯性 Pitched：倾斜的 histogram：柱状图breakdown：破坏 Unit 14 Distillation Dumped or ordered packings:乱堆或整齐堆放填料 Plate:板 Tray:塔盘 Hold-down and support plates:固定和支撑板 Fraction:馏分 Cascading:成瀑布落下，分多级进行 Reboiler：再沸器Overhead condenser: 塔顶冷凝器 Reflux:回流 Distillate：馏出物Countercurrent:逆流 Relative volatility：相对挥发度 Rectifying section:精馏段 Stripping section:提留段 Sidestream：侧线馏分 Circumvent:回避Hypothetical:假设的 Equilibrium-stage：平衡级（理论板） Tray efficiency:塔板效率 The number of hypothetical equilibrium stages required is then converted to a number actual trays by means of tray efficiencies, which describe the extent to which the performance of actual contact tray duplicates the performance of an equilibrium stage 然后理论塔板数通过塔板效率被转换成实际塔板数；塔板效率是实际塔板表现和理论塔板表现的比值。

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。

化学化工类外文翻译+原文

化学工业Chemical Industry1.化学工业的起源尽管化学品的使用可以追溯到古代文明时代，但我们所谓的现代化学工业的发展却是从近代才开始的。

可以认为它起源于工业革命其间，大约在1800年，并发展成为为其它工业部门提供化学原料的产业。

比如制肥皂所用的碱，棉布生产所用的漂白粉，玻璃制造业所用的硅及Na2CO3。

我们会注意到所有这些都是无机物。

有机化学工业的开始是在十九世纪六十年代以William Henry Perkin 发现第一种合成染料—苯胺紫并加以开发利用为标志的。

20世纪初，德国花费大量资金用于实用化学方面的重点研究，到1914年，德国的化学工业在世界化学产品市场上占有75%的份额。

这要归因于新染料的发现以及接触法制硫酸和氨的哈伯生产工艺的发展。

而后者需要较大的技术突破使得化学反应第一次可以在非常高的压力条件下进行。

这方面所取得的成绩对德国很有帮助。

特别是由于1914年第一次世界大战的爆发，对以氮为基础的化合物的需求飞速增长。

这种深刻的改变一直持续到第一次世界大战结束至第二次世界大战开始这段时间(1918-1939年)。

1940年以来，化学工业一直以引人注目的速度飞速发展。

尽管这种发展的速度近年来已大大减慢。

化学工业的发展由于1950年以来石油化学领域的研究和开发大部分在有机化学方面取得。

石油化工在60年代和70年代的迅猛发展主要是由于人们对于合成高聚物如聚乙烯、聚丙烯、尼龙、聚脂和环氧树脂的需求巨大增加。

今天的化学工业已经是制造业中有着许多分支的部门，并且在制造业中起着核心的作用。

它生产了数千种不同的化学产品，而人们通常只接触到终端产品或消费品。

这些产品被购买是因为他们具有某些性质适合人们的一些特别的用途，例如，用于盆的不粘涂层或一种杀虫剂。

这些化学产品归根到底是由于它们能产生的作用而被购买的。

2.化学工业的定义在本世纪初，要定义什么是化学工业是不太困难的，因为那时所生产的化学品是很有限的，而且是非常清楚的化学品，例如，烧碱，硫酸。

中英文文献以及翻译(化工类)

Foreign material：Chemical Industry1.Origins of the Chemical IndustryAlthough the use of chemicals dates back to the ancient civilizations, the evolution of what we know as the modern chemical industry started much more recently. It may be considered to have begun during the Industrial Revolution, about 1800, and developed to provide chemicals roe use by other industries. Examples are alkali for soapmaking, bleaching powder for cotton, and silica and sodium carbonate for glassmaking. It will be noted that these are all inorganic chemicals. The organic chemicals industry started in the 1860s with the exploitation of William Henry Perkin’s discovery if the first synthetic dyestuff—mauve. At the start of the twentieth century the emphasis on research on the applied aspects of chemistry in Germany had paid off handsomely, and by 1914 had resulted in the German chemical industry having 75% of the world market in chemicals. This was based on the discovery of new dyestuffs plus the development of both the contact process for sulphuric acid and the Haber process for ammonia. The later required a major technological breakthrough that of being able to carry out chemical reactions under conditions of very high pressure for the first time. The experience gained with this was to stand Germany in good stead, particularly with the rapidly increased demand for nitrogen-based compounds (ammonium salts for fertilizers and nitric acid for explosives manufacture) with the outbreak of world warⅠin 1914. This initiated profound changes which continued during the inter-war years (1918-1939).Since 1940 the chemical industry has grown at a remarkable rate, although this has slowed significantly in recent years. The lion’s share of this growth has been in the organic chemicals sector due to the development and growth of the petrochemicals area since 1950s. The explosives growth in petrochemicals in the 1960s and 1970s was largely due to the enormous increase in demand for synthetic polymers such as polyethylene, polypropylene, nylon, polyesters and epoxy resins.The chemical industry today is a very diverse sector of manufacturing industry, within which it plays a central role. It makes thousands of different chemicals whichthe general public only usually encounter as end or consumer products. These products are purchased because they have the required properties which make them suitable for some particular application, e.g. a non-stick coating for pans or a weedkiller. Thus chemicals are ultimately sold for the effects that they produce.2. Definition of the Chemical IndustryAt the turn of the century there would have been little difficulty in defining what constituted the chemical industry since only a very limited range of products was manufactured and these were clearly chemicals, e.g., alkali, sulphuric acid. At present, however, many intermediates to products produced, from raw materials like crude oil through (in some cases) many intermediates to products which may be used directly as consumer goods, or readily converted into them. The difficulty cones in deciding at which point in this sequence the particular operation ceases to be part of the chemical industry’s sphere of activities. To consider a specific example to illustrate this dilemma, emulsion paints may contain poly (vinyl chloride) / poly (vinyl acetate). Clearly, synthesis of vinyl chloride (or acetate) and its polymerization are chemical activities. However, if formulation and mixing of the paint, including the polymer, is carried out by a branch of the multinational chemical company which manufactured the ingredients, is this still part of the chemical industry of does it mow belong in the decorating industry?It is therefore apparent that, because of its diversity of operations and close links in many areas with other industries, there is no simple definition of the chemical industry. Instead each official body which collects and publishes statistics on manufacturing industry will have its definition as to which operations are classified as the chemical industry. It is important to bear this in mind when comparing statistical information which is derived from several sources.3. The Need for Chemical IndustryThe chemical industry is concerned with converting raw materials, such as crude oil, firstly into chemical intermediates and then into a tremendous variety of other chemicals. These are then used to produce consumer products, which make our livesmore comfortable or, in some cases such as pharmaceutical produces, help to maintain our well-being or even life itself. At each stage of these operations value is added to the produce and provided this added exceeds the raw material plus processing costs then a profit will be made on the operation. It is the aim of chemical industry to achieve this.It may seem strange in textbook this one to pose the question “do we need a chemical industry?” However trying to answer this question will provide(ⅰ) an indication of the range of the chemical industry’s activities, (ⅱ) its influence on our lives in everyday terms, and (ⅲ) how great is society’s need for a chemical industry. Our approach in answering the question will be to consider the industry’s co ntribution to meeting and satisfying our major needs. What are these? Clearly food (and drink) and health are paramount. Other which we shall consider in their turn are clothing and (briefly) shelter, leisure and transport.(1)Food. The chemical industry makes a major contribution to food production in at least three ways. Firstly, by making available large quantities of artificial fertilizers which are used to replace the elements (mainly nitrogen, phosphorus and potassium) which are removed as nutrients by the growing crops during modern intensive farming. Secondly, by manufacturing crop protection chemicals, i.e., pesticides, which markedly reduce the proportion of the crops consumed by pests. Thirdly, by producing veterinary products which protect livestock from disease or cure their infections.(2)Health. We are all aware of the major contribution which the pharmaceutical sector of the industry has made to help keep us all healthy, e.g. by curing bacterial infections with antibiotics, and even extending life itself, e.g. ß–blockers to lower blood pressure.(3)Clothing. The improvement in properties of modern synthetic fibers over the traditional clothing materials (e.g. cotton and wool) has been quite remarkable. Thus shirts, dresses and suits made from polyesters like Terylene and polyamides like Nylon are crease-resistant, machine-washable, and drip-dry or non-iron. They are also cheaper than natural materials.Parallel developments in the discovery of modern synthetic dyes and the technology to “bond” th em to the fiber has resulted in a tremendous increase in the variety of colors available to the fashion designer. Indeed they now span almost every color and hue of the visible spectrum. Indeed if a suitable shade is not available, structural modification of an existing dye to achieve this canreadily be carried out, provided there is a satisfactory market for the product.Other major advances in this sphere have been in color-fastness, i.e., resistance to the dye being washed out when the garment is cleaned.(4)Shelter, leisure and transport. In terms of shelter the contribution of modern synthetic polymers has been substantial. Plastics are tending to replace traditional building materials like wood because they are lighter, maintenance-free (i.e. they are resistant to weathering and do not need painting). Other polymers, e.g. urea-formaldehyde and polyurethanes, are important insulating materials f or reducing heat losses and hence reducing energy usage.Plastics and polymers have made a considerable impact on leisure activities with applications ranging from all-weather artificial surfaces for athletic tracks, football pitches and tennis courts to nylon strings for racquets and items like golf balls and footballs made entirely from synthetic materials.Like wise the chemical industry’s contribution to transport over the years has led to major improvements. Thus development of improved additives like anti-oxidants and viscosity index improves for engine oil has enabled routine servicing intervals to increase from 3000 to 6000 to 12000 miles. Research and development work has also resulted in improved lubricating oils and greases, and better brake fluids. Yet again the contribution of polymers and plastics has been very striking with the proportion of the total automobile derived from these materials—dashboard, steering wheel, seat padding and covering etc.—now exceeding 40%.So it is quite apparent even from a brief look at the chemical industry’s contribution to meeting our major needs that life in the world would be very different without the products of the industry. Indeed the level of a country’s development may be judged by the production level and sophistication of its chemical industry4. Research and Development (R&D) in Chemical IndustriesOne of the main reasons for the rapid growth of the chemical industry in the developed world has been its great commitment to, and investment in research and development (R&D). A typical figure is 5% of sales income, with this figure being almost doubled for the most research intensive sector, pharmaceuticals. It is important to emphasize that we are quoting percentages here not of profits but of sales income, i.e. the total money received, which has to pay for raw materials, overheads, staff salaries, etc. as well. In the past this tremendous investment has paid off well, leading to many useful and valuable products being introduced to the market. Examplesinclude synthetic polymers like nylons and polyesters, and drugs and pesticides. Although the number of new products introduced to the market has declined significantly in recent years, and in times of recession the research department is usually one of the first to suffer cutbacks, the commitment to R&D remains at a very high level.The chemical industry is a very high technology industry which takes full advantage of the latest advances in electronics and engineering. Computers are very widely used for all sorts of applications, from automatic control of chemical plants, to molecular modeling of structures of new compounds, to the control of analytical instruments in the laboratory.Individual manufacturing plants have capacities ranging from just a few tones per year in the fine chemicals area to the real giants in the fertilizer and petrochemical sectors which range up to 500,000 tonnes. The latter requires enormous capital investment, since a single plant of this size can now cost $520 million! This, coupled with the widespread use of automatic control equipment, helps to explain why the chemical industry is capital-rather than labor-intensive.The major chemical companies are truly multinational and operate their sales and marketing activities in most of the countries of the world, and they also have manufacturing units in a number of countries. This international outlook for operations, or globalization, is a growing trend within the chemical industry, with companies expanding their activities either by erecting manufacturing units in other countries or by taking over companies which are already operating there.化学工业1.化学工业的起源尽管化学品的使用可以追溯到古代文明时代，我们所谓的现代化学工业的发展却是非常近代（才开始的）。

化工专业英语第五篇翻译

Distillation 蒸馏The separating operation called distillation utilizes1 vapor and liquid phases at essentially the same temperature and pressure for the coexisting zones. Various kinds of device such as dumped2(倾倒;堆放) or ordered3 packings4 and plates5 or trays5 are used to bring the two phases into intimate （亲密的；隐私的）contact. Trays are stacked（叠，层叠）one above the other and enclosed（装入）in a cylindrical shell to form a column6. Packings are also generally contained（包含；容纳）in a cylindrical shell between hold-down7 and support plates.称为蒸馏的分离操作是利用蒸汽相和液体相在基本相同的温度和压力下相互接触进行的。

各种设备，诸如散装的或者整砌的填料以及塔板或者塔盘用于使两相充分接触。

一块塔盘置于另一块之上并装入一个圆筒中形成一座塔。

填料一般也是装入圆筒中的支承板与压板之间。

1. Continuous Distillation (Fig.7) 连续蒸馏The feed material, which is to be separated into fractions1, is introduced at one or more points along the column shell. Because of the difference on gravity between vapor and liquid phases, liquid runs down the column, cascading2(成瀑布状落下；溢流) from tray to tray, while vapor flows up the column, contacting liquid at each tray.需要分离为几个馏分的物料从塔壳上的一个位置，或者几个沿塔高分布的位置进入塔中。

化学化工类外文翻译原文

化学化工类外文翻译原文Original Text:Chapter 1 Introduction1.1 BackgroundNuclear energy has been providing a significant share of the world’s electricity for more than half a century. Currently, nuclear power plants generate approximately 10% of the world’s electricity supply, with this figure increasing to over 30% in some countries such as France [1]. However, for nuclear energy to continue to be an important source of electricity in the future, the safe and efficient operation of nuclear power plants must be ensured. A key component of ensuring safe and efficient operation is the availability of inspection techniques that can detect defects, assess their severity, and monitor their growth over time.The presence of defects in materials used in nuclear power plants can arise from a number of sources including fabrication, welding, and service exposure. Defects can manifest themselves as a variety of features such as cracks, voids, inclusions, and inhomogeneities. Defects can be classified based on their size, shape, and orientation, with some defectsbeing more critical to the performance and safety of a component than others. For example, surface-breaking transverse cracks in pressure vessel components can be particularly critical since they can rapidly propagate under service loading and can lead to catastrophic failure if not detected and remedied in a timely manner [2].Inspection techniques used to detect and monitor defects in nuclear power plant components are continually evolving. Inspection methods have traditionally included visual examination, ultrasonics, radiography, and eddy current testing [3]. These techniques have proven reliable and effective, but have limitations such as the inability to inspect certain materials and geometries. In addition, advances in materials science and technology have led to the development of new materials with different physical and chemical properties that may not be well-suited to traditional inspection techniques. Therefore, there is a need to develop and optimize inspection techniques that are capable of detecting andmonitoring defects in advanced materials and structures.1.2 Objectives and ScopeThe primary objective of this chapter is to provide an overview of the different types of inspection techniques that are currently used in the nuclearpower industry for detecting, characterizing, and monitoring defects in materials and components. The chapter will discuss the limitations of current inspection techniques and the challenges associated with the inspection of advanced materials and structures. The chapter will also highlight recent developments in inspection techniques including the use of advanced sensors, imaging, and data analysis techniques.The scope of the chapter will cover a range of inspection techniques used in the nuclear power industry including visual examination, ultrasonics, radiography, eddy current testing, and other techniques such as thermography and acoustic emission testing. The chapter will focus on the application of these techniques to welds, pressure vessels, steam generators, and reactor components. The chapter will also briefly discuss the use of inspection techniques for other applications such as monitoring corrosion and degradation of materials.1.3 Organization of the ChapterThe remainder of this chapter is organized as follows. Section 2 provides an overview of visual examination and its application to the inspection of nuclear power plant components. Section 3 describes ultrasonic inspection techniques and their use in detecting and characterizing defects in materials and components.Section 4 discusses radiography and its use forimaging defects in materials. Section 5 covers eddy current testing and its application to the detectionof surface and subsurface defects. Section 6 provides an overview of other non-destructive evaluation techniques such as thermography and acoustic emission testing. Section 7 summarizes recent developments in inspection techniques including the use of advanced sensors and imaging techniques. Section 8 concludesthe chapter with a discussion of challenges and future directions in inspection technology for nuclear power plant components.中文翻译：第一章绪论1.1 背景核能已经为全球电力供应提供了半个多世纪的重要部分。

中文和外文化工文献数据库大全

中文和外文化工文献数据库大全一、中文数据库1、清华同方学术期刊网 /中国最大的数据库，内容较全。

收录了5000多种中文期刊，1994年以来的数百万篇文章，并且目前正以每天数千篇的速度进行更新。

阅读全文需在网站主页下载CAJ全文浏览器。

2、维谱全文数据库 /zk/bin/home.htm文献收录1989年以来的全文。

只是扫描质量有点差劲，1994年以后的数据不如CNKI全。

阅读全文需下载维谱全文浏览器，约7M。

目前，以下站点提供免费检索3、万方数据库收录了核心期刊的全文，文件为pdf格式，阅读全文需Acrobat Reader 浏览器。

二、外文全文站点(所有外文数据库，阅读全文均需要Acrobat Reader)1.Highwire /世界上第二大免费数据库（最大的免费数据库没有生物学、农业方面的文献）,该网站提供部分文献的免费检索,和所用文献的超级链接,免费文献在左边标有FREE.2.ScienceDirect /Elsevier Science是荷兰一家全球著名的学术期刊出版商，每年出版大量的农业和生物科学、化学和化工、临床医学、生命科学、计算机科学、地球科学、工程、能源和技术、环境科学、材料科学、航空航天、天文学、物理、数学、经济、商业、管理、社会科学、艺术和人文科学类的学术图书和期刊，目前电子期刊总数已超过1200多种（其中生物医学期刊499种）,其中的大部分期刊都是SCI、EI等国际公认的权威大型检索数据库收录的各个学科的核心学术期刊。

3.Wiley InterScience：/cgi-bin/home Wiley InterScience是John Wiely & Sons 公司创建的动态在线内容服务，1997年开始在网上开通。

通过InterScience，Wiley公司以许可协议形式向用户提供在线访问全文内容的服务。

Wiley InterScience收录了360多种科学、工程技术、医疗领域及相关专业期刊、30多种大型专业参考书、13种实验室手册的全文和500多个题目的Wiley学术图书的全文。

化工专业英语第一片翻译

Elements and Compounds元素与化合物Elements are pure substances that can not be decomposed(分解) into simpler substances by ordinary chemical changes. At present there are 109 known elements. Some common elements that are familiar to you are carbon, oxygen, aluminum, iron, copper, nitrogen, and gold. The elements are the building blocks of matter just as the numerals 0 through 9 are the building blocks for numbers. To the best of1 our knowledge, the elements that have been found on the earth also comprise(包含) the entire universe.元素是单纯的物质，不能通过一般的化学变化分解成为更简单的物质。

目前已知有109个元素。

一些你熟悉的常见元素是碳、氧、铝、铁、氮和金。

元素是组成物质的基本单元，就象0到9的数字是组成数的基本单元一样。

就我们所知，已经在地球上发现的元素也是组成整个宇宙的元素。

About 85% of (85 percent of) the elements can be found in nature , usually combined with other elements in minerals and vegetable matter or in substances like water and carbon dioxide. Copper, silver, gold, and about 20 other elements can be found in highly pure forms. Sixteen elements are not found in nature; theyhave been produced in generally small amounts in nuclear explosions (爆炸)and nuclear research. They are man-made elements.大约有85%的元素可以在大自然的矿物或者植物中，以及如水和二氧化碳这样的物质中找到，通常与别的元素结合。

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。

化工英文文献及翻译

由从粉煤灰中制取的硫酸铝盐合成氧化铝姓名：曹巍巍学号：2011200387 学院：化工学院摘要：由粉煤灰制得的NH4Al(SO4)2和氨在水中适宜的PH环境下可制得高纯度氧化铝（>99.9%）。

用XRD、TG/DTA、SEM和激光分散技术来检测热源（微波对硫酸铝铵分解和氧化铝性质的影响。

和传统的加热方法相比，微波加热来分解硫酸铝铵以制得更高比表面积的α-Al2O3粉末。

关键词：硫酸铝盐、粉煤灰、微波加热1、简介NH4Al(SO4)2是一种制备高纯度的活性氧化铝的潜在原料[1-3],硫酸铝盐通常是一种从含铝原材料中生产氧化铝的中间材料[4-5]。

硫酸铝盐的分解和生成物向氧化铝的转化在相关文献中已有报告[1-3,6]，但总体上结果还有一些分歧。

很多社会学家和相关的科学家对回收工业废物来制取高价值的材料很感兴趣。

在应用热点的地区，从大量的由煤燃烧产生的粉煤灰中进行资源回收是一个制得关注的问题。

粉煤灰由主要含有SiO2、Al2O3的无机粒子组成，这些粒子通常以煤胞的形式存在。

Al2O3是一种普遍使用的高性能原料，从粉煤灰中合成Al2O3具有很大的商业利益。

粉煤灰含有大量的杂质，如Fe2O3、Na2O、K2O、P2O5、MaO、MgO、CaO 和SiO2[7]，这样纯粹的用酸或碱来直接提取纯净的氧化铝是很困难的。

一种从粉煤灰中获取高纯氧化铝的方法就是把硫酸铝盐作为中间产物来制。

将硫酸铝盐作为中间产物的优点就使通过直截了当的可溶沉淀物的过程来提高纯度。

和传统的加热过程相比，微波加热有它自身的优点，它具有选择性、直接性、内部性、控制性。

所以，微波在材料制备中广泛地应用[8-10]。

用酸可加速有机材料和无机材料的溶解过程，这是由于微波产生的内部热量引起的[11,12]。

目前工作的目的就是促进回收粉煤灰及生产高纯度氧化铝。

微波加热的影响和由粉煤灰制得的Al的热效应已经进入研究，氧化铝也已表征。

2、实验过程粉煤灰原片包含了23.29% Al2O3的和53.83%的SiO2，，它包含了大量的硅酸盐矿物质，它是一种混合的鳞片象和近球面形颗粒，比表面积为3.82m2/g,凝聚的大小为42.1μm（<90%）.粉煤灰在600℃下在空气中焙烧2小时以出去残留的碳，随后在乙醇中球磨24小时，经过旋转真空蒸发后，干燥的粉末研磨到可通过200目的筛。

化学专业英语文献翻译

英语文献翻译学院：化学化工学院班级：应化1106姓名：***吴海军学号：***********20110222227Quantifying the Cluster of Differentiation 4 Receptor Density on Human T Lymphocytes Using Multiple Reaction Monitoring Mass Spectrometry多反应监测质量光谱法应用于人类T淋巴细胞量化分化抗原簇4受体密度ABSTRACT: Cluster of differentiation 4 (CD4) is an important glycoprotein containing four extracellular domains, a transmembrane portion and a short intracellular tail. It locates on the surface of various types of immune cells and performs a critical role in multiple cellular functions such as signal amplification and activation of T cells. It is well-known as a clinical cell surface protein marker for study of HIV progression and for defining the T helper cell population in immunological applications. Moreover, CD4 protein has been used as a biological calibrator for quantification of other surface and intracellular proteins. However, flow cytometry, the conventional method of quantification of the CD4 density on the T cell surface depends on antibodies and has suffered from variables such as antibody clones, the fluorophore and conjugation chemistries, the fixation conditions, and the flow cytometric quantification methods used. In this study, we report the development of a highly reproducible nano liqui d chromatography−multiple reaction monitoring mass spectrometry-based quantitative method to quantify the CD4 receptor density in units of copy number per cell on human CD4+ T cells. The method utilizes stable isotope-labeled full-length standard CD4 as an internal standard to measure endogenous CD4 directly, without the use of antibodies. The development of the mass spectrometry-based approach of CD4 protein quantification is important as a complementary strategy to validate the analysis from the cytometry-based conventional method. It also provides new support for quantitative understanding and advanced characterization of CD4 on CD4+ T cells.摘要：集群分化4(CD4)是一种重要的糖蛋白，它包含四个胞外区域,横跨膜的部分和短的细胞内尾巴。

化工专业英语(刘庆文)09065课文和阅读读材料翻译部分

化工专业英语（参考译文）Specailized English for Chemical Industry刘庆文目录模块一化工生产第一单元碳酸钠的生产第二单元聚乙烯的生产第三单元炼油第四单元精细化学品第五单元结晶第六单元液液萃取第七单元分析化学模块二职业健康与卫生第八单元化学工业的危险因素第九单元职业危害与保护第十单元个人保护模块三化学工业安全第十一单元化学危险品的危害第十二单元电器事故第十三单元化工工艺安全信息模块四环境保护第十四单元废气减排第十五单元废物利用第十六单元化学废物的循环第十七单元清洁生产模块五质量第十八单元质量保证第十九单元质量管理体系第二十单元药品生产质量管理规范模块一化工生产第一单元碳酸钠的生产碳酸钠是钠的碳酸盐（也称之为洗涤碱，苏打结晶或纯碱）。

它通常以七水结晶形式存在，很容易风化变为白色的一水合物粉末。

它也是人们熟知的家庭日用水软化剂。

碳酸钠有一种冷碱味，它可以从许多植物灰中提取出来。

大量的碳酸钠是用索尔韦法通过食盐来生产的。

用途生产玻璃是碳酸钠最重要的用途。

当碳酸钠与沙子和碳酸钙混合在一起，加热到很高的温度，然后快速冷却时，就产生了玻璃。

这类玻璃叫做钠钙玻璃。

碳酸钠在各种环境下也可以用作相对较强的碱。

例如，碳酸钠用作pH调节剂，以维持大多数显影剂反应所需的稳定的碱性条件。

它是市政水池常用的添加剂，用来中和氯的酸效应，提高pH值。

化学上，它常常用作电解质。

此外，与生成氯气的氯离子不同，碳酸根离子不腐蚀阳极。

它还可以用作酸碱滴定的基准物，因为它是空气中稳定存在的固体，容易准确称量。

生产索尔韦法：1861年比利时工业化学家，欧内斯特·索尔韦发明了一种方法，使用氨将氯化钠转化为碳酸钠。

索尔韦法是在一个大的空塔内进行的。

在塔底，碳酸钙（石灰石）被加热释放出二氧化碳。

CaCO3→ CaO + CO2在塔顶，氯化钠和氨的浓溶液进入塔内。

随着二氧化碳气泡穿过溶液，生成碳酸氢钠沉淀：NaCl + NH3 + CO2 + H2O → NaHCO3 + NH4Cl碳酸氢钠通过加热转化为碳酸钠，并释放出水和二氧化碳：2 NaHCO3→ Na2CO3 + H2O + CO2同时，通过加热氯化铵和石灰（氢氧化钙），可以重新制备氨。

石油化工类院校Advanced Space Technology for Oil Spill Detection—毕业设计文献翻译_英文原版+中文翻译

(中文翻译从第11页开始，1——10页为英文原版）希望能帮到那些做毕业设计时为文献翻译而惆怅的童鞋们Advanced Space Technology for Oil Spill DetectionMaral H. Zeynalova, Rustam B. Rustamov and Saida E. SalahovaAbstract Environmental pollution, including oil spill is one of the major ecological problems. Negative human impacts demands to develop appropriate legislations within the national and international framework for marine and coastal environment as well as the onshore protection. Several seas, for instance the Mediterranean, the Baltic and the North Seas were declared as special areas where ship discharges are completely prohibited (Satellite Monitoring, LUKOIL).In this regard environmental protection of the Caspian Sea has a priority status for Azerbaijan as a closed water basin ecosystem. This area, as a highly sensitive area in the World requires permanent ecological monitoring services where oil and gas from the subsurface of the Caspian Sea is developing almost more than a century. This status of the Caspian Sea is expected to be retention at least for the coming ﬁfty years.Remote sensing is a key instrument for successful response to the onshore and offshore oil spills impacts. There is an extreme need for timely recognition of the oil spilled areas with the exact place of location, extent of its oil contamination and veriﬁcation of predictions of the movement and fate of oil slicks.Black Sea region is expected to have a dramatic increase in the trafﬁc of crud e oil (mainly from the Caspian region). The main reason for these changes is the growth of oil industry in both Kazakhstan and Azerbaijan. The real substantial changes in tanker movements and routs are not clear till now.A necessity for a continuous observation of the marine environment comes afore when clarifying the tendencies of changes in the concentration of the particularly dangerous polluting substances as well as the behavior of different kinds of polluting substances in the detected area i.e., creation of a system for monitoring the pollution (L.A. Stoyanov and G.D. Balashov, UNISPACE III, Varna, Bulgaria).The exploration of geological and oil production started in the shelf of the Caspian Sea a long time ago. The Caspian Sea is a highly sensitive region on ecological and biodiversity point of view. Oil dumps and emergency oil spill have an extremely badinﬂuence on the marine and earth ecosystem and can lead to the ecological balance.Certainly the general issue of oil and gas pipeline safety includes aspects of natural disasters and problems related to the environment. After successful construction of the Baku-Tbilisi-Ceyhan oil pipeline and Baku-Tbilisi-Erzrum gas pipeline these aspects especially became very important for Azerbaijan and deﬁnitel y, for the region. The Baku-Tbilisi-Ceyhan Crude Oil Export Pipeline comprises a regional crude oil export transportation system, approximately 1750 in overall length.Generally, oil spill monitoring in the offshore and onshore is carried out by means of specially equipped airborne, ships and satellites. Obviously, daylights and weather conditions limit marine and aerial surveillance of oil spills.Keywords Space technology. Space image. Oil spil DetectionIntroductionGenerally, oil spillage is categorized into four groups: minor, medium, major and disaster. Minor spill neither takes place when oil discharge is less than 25 barrels in inland waters nor less than 250 barrels on land, the offshore or coastal waters that does nor pose a threat to the public health or welfare. In case of the medium spill the spill must be 250 barrels or less in the inland water or from 250 to 2 500 barrels on land, offshore and coastal water while for the major spill, the discharge to the inland waters is in excess of 250 barrels on land, offshore or coastal waters. The disaster refers to any uncontrolled well blowout, pipeline rupture or storage tank failure which poses an immediate threat to public health or welfare.Satellite-based remote sensing equipment installed in the satellite is used for monitoring, detecting and identifying sources of accidental oil spills. Remote sensing devices include the use of infrared, video and photography from airborne platforms. In the mean time presently a number of systems like air borne radar, laser ﬂuorescence, microwave radiometer, SAR, ERS 1, ERS 2, ENVISAT and LANDSAT satellite systems are applied for the same purposes. Currently more than a dozen satellites are in the orbit producing petabytes of data daily. Detailed description of these satellites, major characteristics of sensors can be summarized as follows:●Spatial resolution of sensors ranges from 1 meter (e.g. IKONOS) to several kilo-meters (e.g. GEOS)●Satellite sensors commonly use visible to near-infrared, infrared and microwaveportions of electromagnetic spectrum;●Spectral resolution of satellite data ranges from single band (Radarsat) to multibands (e.g. MODIS with 36 bands)●Temporal resolution (repeat time) varies from several times a day (e.g. Meteosat)●The majority of satellites are sun synchronous and polar orbiting, crossing the equator at around 10 a.m. local time during theirdescending pass●Digital data are available in both panchromatic (black and white) and multi- spectral modesUsing the recent advanced space technology, the following methodology can be applied for the oil spills detections:●Development of oil spill detection methods for the purpose of practical oil spill surveillance related to the space imagery withapplication of any weather conditions;●Adaptation of the observation to other systems to predict the oil spill spread direction and ﬂow rate characteristics, determ inationthe pollutant contaminations;●Development of appropriate data and user interfaceThere is a need for effectively direct spill countermeasures such as mechanical containment and recovery, dispersant application and burning, protection of sites along threatened coastlines and the preparation of resources for the shoreline clean-up.As it is mentioned in the beginning, the remote sensing is one of the main methods for an effective response to the oil spills environmental monitoring. Timely response to an oil spill requires rapid investigation of the spill site to determine its exact location, extent of oil contamination, oil spill thickness, in particular.Policy makers, managers, scientists and the public can view the changing environment using the satellite images. Remote sensing is the discipline of observing the Earth’s surface without direct contact with the objects located a t the surface. It allows obtaining information about the planet and human activities from a distance which can reveal interesting features that may not be possible or affordable from the ground level. One of the applications of remote sensing is water and coastal resources. It is essential to undertake the following aspects while using the remote sensing method:●Determination of surface water areas●Monitoring the environmental effects of human activities;●Mapping ﬂoods and ﬂood plains;●Determination of the extent of snow and ice;●Measuring glacial features;●Mapping shoreline changes;●Tracing oil and pollutions.The fact that remote sensing allows multi-temporal analysis is also very important. This means that an area of interest can be monitored over time so that changes can be detected. It allows analyzing phenomena like vegetation growth during different seasons, the extent of annual ﬂoods, the retreat of glaciers or the spread of forest ﬁres or oil spills (Vhenenye Okoro, 2004).Remote sensing is a useful method in several modes of oil spill control, including a large scale area of surveillance ability,speciﬁc site monitoring and advantages of technical and technological assistance in emergency cases. There is a signiﬁcant capacity of providing essential information to enhance strategic and tactical decision-making, decreasing response costs by facilitating rapid oil recovery and ultimately minimizing impacts.Observation can be undertaken visually or by using remote sensing systems. In remote sensing, a sensor other than human vision or conventional photography is used to detect or map oil spills.Oil Spill DetectionOil production and transportation is started on the offshore “Azeri – Chiraq –Guneshli” oilﬁeld, located at the Azerbaijani sector of the Caspian Sea. Therefore development and implementation of onshore and offshore oil spill monitoring and detection are highly important for the Caspian Sea basin countries. Figure 1 shows the overall map of the Caspian Sea region countries.Oil statistics of the major Caspian Sea oil producing countries are presented in Table 1.For visual observations of oil spill from the air using the video photography are the simplest, most common and convenient method of determining the location and extent (scale and size) of an oil spill. There are a number of sensors on surveillance of the sea surface:●Microwave radiometers which allow the determination of the oil thickness;●Ultraviolet and infrared scanners which allow to detect respectively very thin and very thick o il ﬁlms;●Laser ﬂuorescence sensors which allow the determination of oil type.Fig. 1 Overall map of the Caspian Sea region countriesApplication of remote sensing method for spilled oil can be discovered using a helicopter, particularly over near-shore waters where their ﬂexibility is an advantage along intricate coasting with cliffs, coves and islands. For the spill response efforts to be focused on the most signiﬁcant areas of the spill, it is important to take into consideration relative and heaviest concentrations of oil. Geographical positioning systems (GPS) or other available aircraft positioning systems creates a positive environment for localization of the oil location. Photography, particularly digital photography is also a useful instrument as a recording tool. It allows viewing the situation on return to base. Many other devices operating in the visible spectrum wavelength, including the conventional video camera are available at a reasonable cost. Dedicated remote sensing aircraft often have built-in downward looking cameras linked with a GPS to assign accurate geographic coordinates.In the open ocean spills show a less need for rapid changes in ﬂying speed, direction and altitude, in these instances the us e of low altitude, ﬁxed-wing aircraft proved to be the most effective tactical method for obtaining information about spills and assisting in spill response.Oil spill detection is still performed mainly by visual observation which is limited to favorable sea and atmospheric conditions and any operation in rain, fog or darkness is eliminated. Visual observations are restricted to the registration of the spill because there is no mechanism for positive oil detection. Very thin oil sheens are also difﬁcult to detect especially in mist y or other conditions that limit vision.Oil is difﬁcult to discover in high seas and among debris or weeds where it can blend in to dark backgrounds such as water, soil or shorelines. Huge naturally occurring substances or phenomena can be mistaken for spilled oil. These include sun glint, wind shadows and wind sheens, biogenic or natural oils from ﬁsh and plants, glacialﬂour (ﬁnely, ground mineral material usually from glaciers) and oceanic or revering fronts where two different bodies of water meet. The usefulness of visual observations is limited, however, it is an economical way to document spills and provide baseline data on the extent and movement of the spilled oil.Estimation of the quantity of oil observed at sea is the main issue for the detection of the oil spill. Observers are generally able to distinguish between sheen and thicker patches of oil. However gauging the oil thickness and coverage is not always easy and it can be more difﬁcult if the sea is rough. It is essential to view all such est imates with considerable caution.Purpose of the remote sensing equipment mounted in aircraft is increasingly used to monitor, detect and identify sources of illegal marine discharges and to monitor accidental oil spills. Remote sensing devices except infrared video and photography from airborne platforms, thermal infrared imaging, airborne laser ﬂuourosensors, airborne and satellite optical sensors use satellite Synthetic Aperture Radar (SAR). Advantages of SAR sensors over optical ones is their ability to provide data in poor weather conditions and during darkness. Remote sensing method operates detecting properties of the surface such as color, reﬂectance, temperature or roughness of the area. Spilled oil can be detected on the surface when it modiﬁes one or more of these properties. Cameras relying on visible light are widely used and may be supplemented by airborne sensors which detect oil outside the visible spectrum and are thus able to provide additional information about the oil. The most commonly applied combinations of sensors include Side-Looking Airborne Radar (SLAR) and downward-looking thermal infrared and ultraviolet detectors or imaging systems.A number of remote sensors placed on Earth observation satellites can also detect spilled oil as well. Optical observation of spilled oil by the satellite requires clear skies, thereby limits the usefulness of such system. SAR is not restricted by the presence of cloud, thus it is a more useful tool. However with radar imagery, it is quite difﬁcult to be certain if an anomalous feature on a satellite image is caused by the presence of oil. Consequently, radar imagery from SAR requires expert interpretation by suitably trained and qualiﬁed personnel to avoid other features being mistaken for oil spills. However, there is a growing interest of developing SAR to deploy on satellite platforms. Oil on the sea surface dampens some of the small capillary waves that normally are present on clean seas. These capillary waves reﬂect radar energy producing a “bright” area in radar imagery known as sea clutter. The presence of an oil slick can be detected as a “dark” area or one with the absence of sea clutter. Unfortunately, oil slicks are not the only phenomena that can be detected in similar manner. There are many other interferences including fresh water slick, calm areas (wind slicks), wave shadows behind land or structures, vegetation or weed beds that calm the water just above them, glacial ﬂour, biogenic oils and whale and ﬁsh sperm. SAR satellite imagery showed that several false signals are present in a large number of scenes (Bern et al., 1993; Wahl et al., 1993). Despite these limitations, radar is an important tool for oil spill remote sensing since it is the only sensor capable of searching large areas. Radars, as active sensors operating in the microwave region of the electromagnetic spectrum are one of the few sensors that can detect at night and through clouds or fog (Schnick S, InSAR and LIDAR, 2001).Oil Spill Monitoring and Data DevelopmentThe Method of Oil Spill MonitoringDue to the operation of the oilﬁeld “Azeri – Chirag –Guneshli” (ACG), located in the Azerbaijani sector of the Caspian Sea oil production was increased. From the beginning of 1997 development of ACG up to December, 1st, 2006 Azerbaijan International Operating Company (AIOC) could extract a crude oil from interior of the Caspian Sea already 81,25 million tons of oil where oilﬁeld “Chirag” produced 51,06 million tons.The pipeline will extend the capacity and as a result of this it is a need of creating a reliable monitoring system for the more sensitive areas with the greatest oil spill risk.Exploration work and oil production began on the Caspian Sea shelf a long time ago. The Caspian Sea is characterized by an extreme ecological sensitivity and a high biodiversity. Oil damps and emergency of oil spill are an extremely bad inﬂuence for the offshore and onshore ecosystems of Absheron peninsula and can lead to an ecological disturbance.Aerial surveys of large areas of the sea to check the presence of oil spills are limited to daylight hours in good weather conditions. Satellite imagery can help greatly in identifying oil spills on water surface.The current challenge to remote sensing and GIS-based investigations is to combine data from the past and the present in order to predict the future. In the meantime it is likely that a long term or integrative study will combine remote sensing data from different sources. This requires a calibration between remote sensing technologies. Discrepancies in post-launch calibrations of certain remote sensing devices may cause artifacts such as surface area change, and so may the shift from one remote sensing source to another. However, it is possible to integrate cartographic and multi-source remote sensing data into a homogeneous time series.Remote sensing plays an integral role in environmental assessment. Remote sensing will never replace the ﬁeld work and observations but it offers a great support in huge areas as follows:●Remote and difﬁcult access areas like dense forests, glaciated areas, swamps, high elevation, etc;●Areas undergoing rapid changes;●Countries with poor infrastructure and limited transportation;●Areas of active natural hazards and disasters: ﬂooded areas, active volcanic regions, forest ﬁres, earthquake and landslidehazardous areas, etc;●Construction of a broad overview or a detailed map of a large area.Remote sensing techniques can increase the speed in which one can analyze a landscape and therefore help make quick and focused decisions.Among the available remote sensing technologies producing high spatial resolution data, aerial photography was superior to space-borne data, despite the higher spectral resolution of the latter. However, digital air-borne multi-spectral imagery such as theCompact Air-Borne Spectrographic Imager (CASI) is at least as accurate as aerial photography for the same purpose and it is less expensive to obtain and therefore more cost effective. It is also important to proceed in the eva luation of new scientiﬁc application of more common imaging techniques such as video and photography from low-ﬂying aircrafts. In space-borne remote sensing, the IKONOS satellite was the ﬁrst one to challenge the very high spatial resolution (1 m resolution) data obtained from air-borne remote sensing technology. The EROS satellite has a spatial resolution of 1.8 m but no multi-spectral capability. However,its future sensors are reported to generate multi-spectral combined with a spatial resolution of 0.82 m. In the mean time imagery, the QUICKBIRD satellite leads the quality list of optical remote sensing with panchromatic imagery of 0.70 m spatial resolution and multi-spectral imagery of 3 m spatial resolution (W. Ziring et al.,Earth Mapping Information, 2002).Required ParametersSpatial resolution requirements are various but it is necessary to consider even for massive oil spills. It is well known that spills at sea from windrows with widths are often less than 10 m. A spatial resolution is greater than it is required to detect these spills. Furthermore, when considering oil spills, information is often required on a relatively short timescale to be useful to spill response personnel. The spatial and temporal requirements for oil spills depend on what use would be given to the data. Table 2 estimates spatial and time requirements for several oil tasks (Brown and Mervin, Ottawa, Canada).At present time such opportunities are available on board the European Space Agency’s ENVISAT (radar ASAR) and ERS-2 satellites and the Canadian Space Agency’s RADARSAT satellite.Oil spillage on the water surface forms oil sheen. When oil is forming a thin layer on the sea surface it will damp the capillary waves. Due to the difference in backscatter signals from the surface covered by oil and areas with the lack of oil, radar satellites may detect oil spill sheens at the sea surface. Oil spills on radar images can be characterized by following parameters:●form (oil pollution are characterized the simple geometrical form);●edges (smooth border with a greater gradient than oil sheen of natural origin);●sizes (greater oil sheen usually are slicks of natural origins);●eographical location (mainly oil spills occur in oil production areas or ways of oil transportation).Besides an oil spillage area scanning of sheen thickness allows to deﬁne the quantity of the spilled oil. Depending on the temperature of water, properties of oil (viscosity, density) thickness of oil spill layer will be different. A critical gap in responding to oil spills is the present lack of capability to measure and accu- rately map the thickness of spilled oil on the water surface. There are no operational sensors, currently available that provide absolute measurement of oil thickness on the surface of water. A thickness sensor would allow spill countermeasures to be effectively directed to the thickest portions of the oil slick. Some infrared sensors have the ability to measure relative oil thickness. Thick oil appears hotter than the surrounding water during daytime. Composite images of an oil slick in both ultraviolet and infrared sensors showed able to show relative thickness in various areas with the thicker portions mapped in infrared and the thin portions mapped in ultraviolet.Oil spills on the sea surface are detectable by imaging radars, because they damp the short surface waves that are responsible for the radar backscattering. The oil spills appear as a dark patches on radar images. However, natural surface ﬁlms often encountered in the coastal regions with biological activity also damp the short surface waves and thus also give rise to dark patches on radar images. Whereas, the shape can identify oil spills. Furthermore, remote sensing can be in use of initializing and validating models that describe the drift and dispersion of oil spills.Figure 2 shows an example of oil spill of the Absheron peninsula oil spill taken by ENVISAT ASAR. This ﬁgure reﬂects a necessity of the permanent monitoring of the Caspian Sea for more sensitive areas.Fig. 2 ENVISAT ASAR image in the Caspian Sea near the Absheron peninsula for oil spill due to the offshore oil productionUnderwater stream and wind transfers the oil placed on the sea surface. Oil moving speed makes approximately 60% from the underwater stream speed and 2–4% from the wind speed (Sh. Gadimova, Thailand, 2002). The following demonstrates disadvantages of the radar satellite images:●in some cases signatures of oil spill are difﬁcult to distinguish a biogenic origin and other sea phenomena;●presence of wind have an essential inﬂuence on oil spill deﬁnition on the water surface.At a gentle breeze (0–3.0 m/s), the water surface looks dark on radar images. In this case oil sheens merge with a darkback ground of the sea and identiﬁcation of pollution becomes impossible. The speed of wind between 3–11 m/s is a sufﬁcient suitable case for identiﬁcation of oil spills, slicks seem a dark on a light water surface. In the high speed of a wind oil spill identiﬁcation will be inconvenient as they disappear from images owing to mixing with the top layer of water.For more optimum monitoring of sea oil spill is recommended to carry out the following:(i) analysis of sea surface currents;(ii) analysis of the information about the sea level, wave height and wind speed;(iii) analysis of the meteorological information, allowing to estimate speed and direction of a spot.Figure 3 shows southern of the Caspian Sea at the Volga estuary. This river carries a heavy load of pollutants originating from fertilizers washed out from agricultural ﬁelds and from industrial and municipal plants. They serve as nutrients for the marine organisms which experience a rapid growth and then generate biogenic surface slicks. The oceanic eddies which become visible on the radar images because the surface slicks follow the surface currents are very likely wind-induced. The most remarkable feature on this image is the mushroom-like feature consisting of two counter-rotating eddies.This is one more example of application of space technology for environmental monitoring of the sea surface.Except foregoing mentioned areas, an application of satellite monitoring for pipelines can include below indicated problems as: ●detection of oil/gas leaking;●no authorized intrusion into a safety zone of object;●detection of failures and an estimation of ecological damage;●detection and monitoring of pipelines moving (can be caused soil substance).Table 3 demonstrates the basic parameters of used equipment for oil spill monitoringRemote Sensing Data AnalysisInvestigation of the petroleum hydrocarbons on a plot and its analysis is advisable to conduct before and after the oil spill, to characterize changes in vegetative condition through time. Figure 4 shows an example of the oil spill accident occurred due to the third party intervention.This area was used for further investigations as a spilled area indicated for a long term ecological monitoring site (David Reister et al., partnership programme)Fig. 4 Oil spilled areaAn implementation of these studies started from the collection of remotely sensed data from ground, airborne and satellite and the results of all information were combined.Oil spill site has a plant canopy dominated by creosote bush (Larrea tridentata) shrub land. Qualitative ﬁeld investigations indicated that upper plant canopy contact with the diesel fuel was manifest as etiolation that resulted in a grey to white color of the upper canopy and a white to slight reddening of the lower canopy graminoids and litter, partial and complete defoliation of shrubs, apparent high mortality of much of the above ground phytomass, including grasses, cactiods and biological crusts and darkening of the orange-red alluvial soil. It was an evident that the spill boundary could be delineated on the bases of smell, as diesel was still volatizing from the soil. These features were still valuable evident one year after the release. It is necessary to note that the canopy dominant, creosote bush is expected to recover from the diesel spill. This aspect of plant physiology is signiﬁcant for studies of resilience in desert ecosystems.Following application of the oil, vegetation damage was assessed visually via changes in leaf color and leaf fall. It showed three main time frames for injuries:●immediate●occurring during the initial growing season and●cumulative, occurring after the initial growing seasonVirtually all aboveground foliage that came into contact with the oil was quickly cleaned up. Turgidity was immediately reduced and foliage appeared dead within several days. The zone of contact was generally limited to the immediate areas and to areas of low relief in the pass of aboveground ﬂowing oil (Jenkins et al., Arctic, 1978). In contrast, cottongrass tussock with a raised, upright growth form and species growing on areas of higher relief kept most of their aboveground biomass above the oil. These species continued to grow and ﬂower despite their being surrounded by oil (Fig. 5)Fig. 5 Cottongrass tussock growing on spill plot despite surrounding oilThe features of vegetation and natural growth as physical and biological parameters depends of the oil spill interaction can be used a key instrument of spectral behaviors of information within the data processing of space images for linear infrastructures.ConclusionAdvances in information systems, satellites imaging systems and improvement software technologies and consequently data processing led to opportunities for a new level of information products from remote sensing data. The integration of these new products into existing response systems can provide a huge range of analysis tools and information products that were not possible in the past. For instance, with the higher resolution of the space imagery and change detection of the linear infrastructure situational awareness and damage and assessment by impact of the variety of reasons can be implemented rapidly and accurately. All this presented information sources can be valuable in the response, recovery and rehabilitation phases of the preparedness management issue.The lack of periodically observation data for satisfaction needs in oil and gas spills is the main obstacle for the mentioned problem. In this regard satellite data can be playing a signiﬁcant place. For more success in this sphere spatial and non spatial data would be integrated with the geographic information system. This system has to be integrated for the regional scale covering the whole regions state around the Caspian Sea.The presented above results show a sensitivity of parameters of various vegetations to the inﬂuences of oil pollution. Such behavior opens an opportunity of use of those behaviors of vegetations for monitoring of the linear infrastructures as environmental indicators. These indicators signiﬁcantly could be in use as a key instrument within the data processing and interpretation of space images for safety and security issues of the transportations of oil and gas pipeline infrastructure.At the time available technologies for successful implementation of issues related to the pipeline safety were discussed. Depends of the existed huge of problems and tasks appropriate technology as well as system can be applied and carried out for these purposesReferencesBern T-I., Wahl T. Anderssen, and R. Olsen (1993) “Oil Spill Detection Using Satellite Based Sar:Experience From A Field Experiment”, Photogrammetric Engineering And Remote Sensing, 59(3), pp. 423–428.Carl E. Brown, and F.F. Mervin, “Emergencies Science Division, Environmental Technology Cen-tre Environment Canada”, Ottawa, Canada.Dahdouh-Guebas F., Kairo J.G., Jayatissa L.P., Cannicci S., and Koedam N. (2002a) “An Ordina-tion Study To View Past, Present And Future Vegetation Structure Dynamics In Disturbed And Undisturbed Mangroves Forests In Kenya And Sri-Lanka”, Plant Ecology, 162(4).。

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。

化工英文文献翻译

Three Common Details of The Compressor Failure AnalysisCompressor Fault Analysis (1) - motor burnedMotor compressor (hereinafter referred to as the compressor) of the fault can be divided into motor failure and mechanical failure (including the crankshaft, connecting rod, piston, valve, cylinder head pad, etc.). Mechanical failure is often the motor overload or stall, is one of the main motor damage.Damage mainly to the motor stator winding insulation damage (short circuit) and the circuit and so on. Stator windings was found damaged hard time, could eventually lead to winding burned. Winding burned, cover up some cause or direct cause of the phenomenon of burning, making the subsequent analysis and cause investigation more difficult.However, the operation of the motor power input is inseparable from the normal, reasonable motor load, good heat dissipation and winding wire insulation layer of protection. From several aspects, not difficult to find reason than burnt windings are six: (1) abnormal load and stall; (2) Winding short circuit caused by metal shavings; (3) contactor problems; (4) Power phase and voltage abnormalities; (5) inadequate cooling; (6) compressor vacuum. In fact, many factors contributed to the more common motor damage.1. Abnormal loads and stallMotor load requirements, including compressed gas load and the load required to overcome mechanical friction. Pressure ratio is too large, or the pressure is too large, the compression process will be more difficult; and increased friction caused by lubrication failure, and extreme cases of motor stall, will greatly increase the electrical load. Lubrication failure, friction increases, is the leading cause of abnormal load. Back to the diluted lubricating oil, oil heat, oil coking deterioration and lack of oil and so will disrupt normal lubrication, leading to lubrication failure. Back to the diluted lubricating oil, affecting the normal friction surface film formation, or even washed away the original film, increasing friction and wear. Compressor overheating will cause the thinning or even high-temperature coking oil, affecting the normal film formation. System back to the oil well, the compressor short of oil, they can not maintain normal lubrication. High-speed rotating crankshaft, connecting rod piston speed movement, there is no friction surface protection film will quickly heat up, local high-temperature rapid evaporation of the oil or coke, to make it more difficult to lubricate the parts, a few seconds can cause severe localized wear. Lubrication failure, local wear, the need for greater torque to the crankshaft. Low-power compressor (such as refrigerators, home air conditioning compressor) as the motor torque, lubrication failure often occurs after the stall (the motor can not rotate) phenomenon, and enter the "stall - Thermal protection - Locked" death cycle, motor burn only a matter of time. The high-power semi-closed compressor motor torque large, local wear will not cause stall, the motor power will be within a certain range increases with the load, causing more serious wear and tear, and even lead to bite cylinder (live seca in cylinder), rod fracture and other serious damage.When the current stall (stall current) is about 4-8 times the normal running current. The moment of starting the motor, the current reached a peak close to or stall current.Because the resistance heat release proportional to the square with the current, start and stall when the winding current will heat up quickly. Thermal protection can protect the electrode in the stall, but generally will not have a response soon, can not prevent such frequent starting winding due to temperature changes. Frequent starts and abnormal load, so that the test winding subjected to high temperature will reduce the magnet wire insulation.In addition, the compressed gas with the compression ratio will be required to increase the load and pressure increases. Therefore, the high temperature compressor for low temperature, or low compressor for high temperature, will affect the electrical load and heat, is not appropriate, will shorten the electrode life.Winding insulation deterioration, if there are other factors (such as metal shavings form conductive loops, acid oil, etc.) with, it is easy to cause a short circuit and damage.2. Scrap metal caused by short circuitWinding metal particles are mixed and ground insulation value of the low short-circuit the culprit. The normal vibration of the compressor running, and every time you start winding by the magnetic force of the pipe, will promote inclusion in the winding and the winding metal shavings between the relative motion between the magnet wire and friction. Sharp edges will scratch the enameled metal shavings insulation, causing short circuits. Sources including the construction of metal debris left behind by the brass shavings, welding slag, compressor internal parts wear and damage (such as broken valves), the fall of the metal shavings and so on. For the closed compressor (including the closed scroll compressor), the metal shavings or broken, would fall on the winding. For semi-hermetic compressors, and some particles with the gas and oil flow in the system, and finally assembled in the magnetic winding; and some metal shavings (such as bearing wear and stator and rotor wear (sweep bore) is generated) will be directly on the winding. Winding metal shavings gathered after a short circuit is only a matter of time.Need to draw particular attention to the two-stage compressor. In the two-stage compressor, back to the normal gas and oil directly back into the first grade (low grade) cylinder, compressed by the pressure of the cooling tube into the motor winding cavity, and the general single-stage compressor and then as second-class (high pressure stage cylinder.) Back to the gas with oil, the compression process has been skating on thin ice, if there are back to liquid again, the first stage cylinder valve can easily be broken. Broken by the pressure valve can enter the winding tube. Therefore, the two-stage compressor than the single-stage compressors are more likely to electrical short circuit caused by metal shavings.Unfortunately, things tend to conspire a piece of the compressor in the boot of a problem when the news channels is often the oil burning. Severe wear of metal surfaces when the temperature is very high, while oil above 175 º C at the start of coking. System, if there is more moisture (vacuum pits not ideal, big oil and refrigerant water, negative pressure air into the return pipe burst, etc.), lubricants acid may occur. Acidic oil will corrode copper and winding insulation layer, on the one hand, it can cause copper plating phenomenon; on the other hand, this acid containing copper atoms very poor insulation properties of lubricating oil, provided the conditions for the winding circuit.3. Contactor problemContacts is an important component in the motor control circuit, one of the best selection of irrational destruction of the compressor can be. The right choice according to the load contacts are extremely important.Contactor must be able to meet the harsh conditions, such as rapid cycling, continuous overload and low voltage. They must have enough surface area to distribute the heat generated by the load current, contact material should be selected to start or stall in such circumstances to prevent high current welding.For safe and reliable, while the compressor contactor to disconnect the three-phase circuit. Copeland is not recommended way to disconnect the two-phase circuits.In the United States, Copeland approved contactor must meet the following four:• contactor must meet ARI Standard 780-78, "Standard for special access" provisions of the work and testing guidelines.• The manufacturer must ensure that the contacts at room temperature in the lowe st 80% of nameplate voltage can be closed.• When using a single contactor, the contactor must be greater than the motor nameplate rated current rating (RLA). Meanwhile, the contactor must be able to withstand motor stall current. If there are other loads downstream of the contactor, such as electrical fans, and so must also be considered.• When using two contactors, each contactor rating of the sub-winding stall must be equal to or greater than the rating of the compressor stall half-winding.Contacts can not be less than the rated current of the compressor nameplate rated current. Size small or poor quality of contact can not withstand the compressor starts, stall, and low voltage high current impact, single-phase or multiphase prone to contact bounce, the phenomenon of welding or even fall off, causing electrical damage.Contact jitter frequently start and stop the motor contactor. Frequent motor starts, a huge starting current and heat, will aggravate the winding insulation aging. Each time you start, the magnetic torque to the motor windings have small mobile and mutual friction. If there are other factors with (such as metal shavings, poor insulation oil, etc.) can easily lead to short circuits between windings. Thermal protection system is not designed to prevent such damage. In addition, the jitter of the contactor coil easy to failure. If you have contact with the coil is damaged, prone to single-phase state.If the small selection of the contactor, the contact arc, and can not afford to open due to the frequent instability of circulatory arrest or heat generated by the voltage control loop may be welded together or from the contact frame in the loss. Welding of the contacts will have a permanent single-phase state, the overload protection device continuously cycle on and off.Needs to be stressed is that after the welding contactor, disconnect the compressor contactor power dependence of all the control loop (such as high and low pressure control, hydraulic control, defrost control, etc.) will all fail, the compressor is unprotected state. Therefore, when the motor burned, check the contacts are essential processes. Contacts lead to motor damage is often forgotten as a major reason.Compressor Fault Analysis (2) - liquid strike1. Processes and phenomena(1) suction valves are breakingCompressed gas compressor is a machine. Typically, compressed air piston 1450 times per minute (half-closed compressor), or 2900 times (all closed compressor), a suction or exhaust to complete the process time is 0.02 seconds or less. Suction and discharge valve plate of the size of the aperture and the suction valve sheet flexibility and strength are designed in accordance with the gas flow. The force from the perspective of the valve, the gas flow impact force is relatively uniform.The density of the liquid is dozens or even hundreds of times the gas, and thus the momentum of the liquid flow much larger than the gas, the impact force is also much larger. Mixed with more droplets aspirated into the cylinder when the flow is two-phase flow. Two-phase flow in the suction valve chip is not only the impact of high intensity and frequency, as if the typhoon beat mixed with pebbles at the window, the destructive self-evident. Is the liquid suction valve are breaking hit one of the typical characteristics and processes.(2) rod fractureCompression stroke of the time about 0.02 seconds, while the discharge process will be more short-lived. Or liquid droplets in the cylinder must be in such a short period of time discharged from the vent, the speed and momentum is significant. The case of exhaust valve and the suction valve sheet film the same, the difference is limited piece exhaust valve plate and spring-bit support is not easy to break. The impact of serious, limit deformation plate will tilt.If the liquid does not evaporate and discharge time cylinder, piston near top dead center when the compressed liquid, due to a very short time, the compressed liquid the process seems to be hit, also came in the metal cylinder head knocking. Compressed liquid is a liquid hammer or another part of the process.Instantly generate high-pressure liquid hit the broken ring of the great, the beginning of the familiar rod bending or breaking, the other pieces of compression force (valve plate, disc pads, crankshaft, piston, piston pin, etc.) will also be deformed or damage, but often overlooked, or confused with the exhaust pressure is too high. Maintenance of the compressor, people will be very easy to find bent or broken connecting rod, and give replacement, and forget to check whether there are other parts of deformed or damaged, thus laying the seeds for future failure.Attack caused by the fracture fluid is different from the axle rod and piston cylinder bite, it can tell. First, the liquid hit causing rod bent or broken in the short span of time, the rod ends of the piston and crankshaft motion freely, and not generally cause serious wear and tear or bite cylinder axle. Despite the broken piece suction valve, the valve can cause debris occasionally serious scratch piston and cylinder surface, but scratch the surface caused by wear and lubrication failure is very different. Secondly, the liquid caused by rod fracture attack is caused by stress, the connecting rod and a compression feature off stubble. Although the bite cylinder piston rod after the squeeze is also likely to fracture, but only to be stuck in the cylinder piston. Link broken axle after more different, connecting rod and crankshaft are badly scratched, resulting in a broken force is shear stress, are not the same broken stubble. Finally, and bite-cylinder front axle, the motor overload, severemotor heating, thermal protection will be action.2. ReasonsObviously, the compressor can cause the liquid fluid is nothing more than hit several sources as follows: 1) back to the fluid, which flows back to the compressor from the evaporator liquid refrigerant or lubricating oil; 2) starts with a liquid foam; 3) compressor lubricant too much. This paper will analyze each of these types of reasons.(1) back to the liquidTypically, back to the compressor run-time solution is the evaporator liquid refrigerant in the suction line back to the compressor through the phenomenon or process.For the refrigeration system expansion valve, expansion valve back to liquid and is closely related to improper selection and use. Expansion valve selection is too large, too small to set superheat, temperature of installation method is not correct or damaged insulation wrap, expansion valve failure can cause back to the fluid. For a small refrigeration system using capillary, the increase will cause excessive fluid back to liquid.Hot gas defrost system using prone to back solution. Regardless of the heat pump reversing valve operation, or by cooling hot gas bypass valve operation, hot gas defrost the evaporator after the formation of large amounts of liquid, the liquid refrigerant in the subsequent start of the run both possible and return to the compressor.In addition, severe frost evaporator fan failure or deterioration of heat transfer, no evaporation will cause the liquid back to liquid. Cold storage temperature fluctuations can also cause frequent reaction failures caused by the expansion valve back to liquid.Back to the liquid medium caused the accident hit mostly in air-cooled type (referred to as air-cooled or air cooled) semi-hermetic compressors and single two-stage compressors, compressor cylinders because they are directly connected with the return pipe, and once back to the fluid, easily lead to fluid strike accidents. Even if the strike did not cause fluid to return fluid into the cylinder will be diluted or washed away the wall of the piston and cylinder lubricating oil, increased piston wear.For the return air (refrigerant vapor) cooled semi-closed and closed compressor, back to the liquid rarely cause fluid attack. But it will dilute the crankcase oil. Contains large amounts of liquid refrigerant in the oil viscosity is low, the friction surface can not form a sufficient oil film, resulting in rapid wear of moving parts. In addition, the refrigerant oil in the transport process in the case of boiling heat will affect the normal transport lubricants. The farther from the pump, the more obvious the more serious problems. If a serious motor side bearing wear, the crankshaft to the side of the settlement could easily lead to the stator and the motor burned sweep Church.Obviously, back to the liquid solution will not only lead to strike, but also the wear of lubricating oil dilution. Wear and current load the motor will be greatly increased, over time will cause motor failure.Difficult to avoid the return liquid cooling system, installation of gas-liquid separator and taking the time to stop using the control can prevent or reduce the harm back to liquid. (2) start with liquidReturn air-cooled compressor is started, the crankcase oil is called the phenomenon of severe blistering start with liquid. When starting with a blistering fluid in the oil sight glass can be clearly observed. Start with the root cause of liquid dissolved in oil and submergedin the oil following a large number of the refrigerant, the pressure suddenly decreases suddenly boiling and cause blistering oil. This phenomenon is similar to our daily lives and suddenly open the coke cola bottle bubble phenomenon. The length of the duration of foaming agent into the area and cooling, usually a few minutes or ten minutes. The surface of a large number of bubbles floating in the oil, and even filled the crankcase. Once the cylinder through the suction inlet, the bubble will be reduced to liquid (a mixture of oil and refrigerant) can easily lead to fluid attack. Obviously, start with a liquid solution due to hit only occurs during the startup process.And back to the liquid is different from cause to start with liquid refrigerant is "refrigerant migration" of the way into the crankcase. Refrigerant migration is the compressor stops running, the evaporator refrigerant in gaseous form, through the trachea way back into the oil absorbed by the compressor or condensing in the compressor oil after mixing with the process or phenomenon.After the compressor is stopped, the temperature will decrease, and the pressure will rise. As the refrigerant vapor lubricant points down, it will absorb the oil surface of the refrigerant vapor, causing crankcase pressure lower than the evaporator pressure phenomenon. Lower oil temperature, the lower the vapor pressure of refrigerant vapor in the greater absorption of force. Evaporator to the crankcase vapor will slowly "migrate." In addition, if the compressor outside, cold weather or at night, the temperature is often lower than the indoor evaporator, the crankcase pressure there is low, the refrigerant can easily migrate to the compressor and into oil by condensation.Refrigerant migration is a very slow process. The longer the compressor is stopped, migrated to the oil in the refrigerant with it. Exist as long as the evaporator liquid refrigerant, this process will be conducted. As the refrigerant dissolved heavy oil, it will sink to the bottom of the crankcase, and oil floating in the above can also absorb more refrigerant.In addition to outside attack likely to cause liquid refrigerant migration will dilute the lubricating oil. Is very dilute oil pump to the friction surface, rinse out the original film may be washed, causing severe wear (a phenomenon often called refrigerant erosion). Wear transition with the gap will become larger, causing oil spills, thus affecting distant parts of the lubrication oil pressure will cause serious protection action.Due to structural reasons, the air-cooled compressor starts reducing crankcase pressure will be much slower, not very severe blistering, the bubble is difficult to enter the cylinder, air-cooled compressor so there is no problem with liquid starting fluid attack.In theory, the compressor crankcase heater installed (electric heater) can effectively prevent refrigerant migration. Short stop (eg at night), the crankcase heater to maintain power, the system can make the oil temperature is higher than other parts, refrigerant migration does not occur. No downtime (such as a winter), the heating oil before you start a few or ten hours, to evaporate the majority of oil in the refrigerant fluid can either start with a greatly reduced possibility of liquid strike , which also can reduce the harm caused by erosion of refrigerant. However, the actual application, the heater power to maintain after the shutdown or give ten hours before the heater power supply is difficult. Therefore, the practical effect of the crankcase heater will be greatly reduced.For larger systems, shut down before the evaporator to the compressor pumping liquidrefrigerant (known as taking the time to stop), can fundamentally prevent refrigerant migration. The pipe on the way back to the installation of gas-liquid separator, refrigerant migration can increase the resistance and reduce migration.Of course, by improving the compressor structure, can prevent refrigerant migration and reduce oil foaming degree. By improving the return-air-cooled compressor oil return path in the motor crankcase cavity and increased channel migration points (back pumps, etc.), you can cut off the access road after the shutdown, the refrigerant can not enter the crankshaft chamber; reduced intake Road and cross the channel to the crankcase when the crankcase pressure to slow down the boot speed, then control the degree of foaming and foam into the cylinder volume.(3) too much oilSemi-hermetic compressors usually have the oil sight glass to observe the oil level. Oil sight glass oil level above the range, indicating that the oil too much. Oil level is too high, high-speed rotation of the crankshaft and connecting rod may hit oil level frequently, causing a lot of splash oil. Once the oil splash fleeing into the inlet, into the cylinder, causing fluid to be hit.Large refrigeration system installation, they often need to add the appropriate lubricant. But for the poor oil return system, to seriously affect oil return to find the root causes of, and blindly added oil is dangerous. Even if the oil level being low, but also pay attention to sudden and large returns lubricating oil (such as after defrost) may cause danger. Attack caused by liquid lubricants are not uncommon.Compressor Failure Analysis (3) - lack of lubrication and lack of lubrication1. Lack of oilLack of oil is very easy to identify one of the compressor failure, compressor short of oil in the crankcase oil when little or no oil.Compressor is a special pump, a large number of refrigerant gas being discharged from the folder and also take a small portion of oil (known as Ben oil or an oil spill.) Ben compressor oil is inevitable, but Ben is different oils speed. Semi-sealed piston compressor discharge in about 2-3% of the oil, while the scroll compressor is 0.5-1%. For a displacement 100m3/hr, crankcase oil storage capacity of 6 liters of 6-cylinder compressor, 3% of the rush of oil means that about 0.3-0.8 liters / minute Ben oil, or running back to the oil-free compressor time for ten minutes.Discharge of the compressor oil does not return, the compressor will be short of oil. Compressor oil return in two ways, one is the oil separator oil return, the other is the return pipe back to the oil. Oil separator installed in the compressor discharge pipe on the road, generally isolated from 50-95% of the Ben oil, back to better effect, fast, greatly reducing the amount of oil into the system piping, which effectively extended the running time of no return oil . Particularly long cold storage refrigeration piping system, ice-making system and flooded the low temperature freeze-drying equipment, ten minutes after boot or even tens of minutes did not return very little fuel oil or return to the situation is not unusual, the design The system will not occur while the compressor low oil pressure shutdown problem. The installation of high efficiency cooling system can greatly extend the oil separator back to the oil-free compressor operation time, after the compressor start to ride back to the oilphase of the crisis-free.Separated from the oil will not enter the system, with the flow of refrigerant in the tube, the formation of the oil cycle. Lubricating oil into the evaporator, the temperature is low because of low solubility on the one hand, part of the oil separated from the refrigerant; the other hand, low temperature viscosity, separated from the oil easily attached to the pipe wall, flow is more difficult . Evaporating temperature is lower, back to the oil more difficult. This requires the evaporation of pipeline design and pipe way back to the design and construction must be conducive to return to the oil, a common practice is to use down-style pipeline design, and to ensure a larger flow rate. For particularly low temperature refrigeration systems, such as -85 ° C and -150 ° C cold chamber for medical, in addition to selection of efficient oil separator, but usually add special solvent to prevent blocking capillaries and expansion valve oil, and help return oil.Practice, the evaporator and back to the trachea caused by improper road design back to the oil problem is not rare. For the R22 and R404A systems, flooded evaporator back to the oil is very difficult to design the system return lines must be very careful. For such systems, the use of highly efficient oil pipeline can greatly reduce the amount of oil into the system, effectively extending the boot back to the pipe back to the oil-free time.When the compressor than the location of the evaporator is high, the vertical back to back on the oil pipe bending is required. Return bends to compact as much as possible to reduce the storage of oil. The spacing between the oil return to the right bend, bend back the amount of oil relatively long time, should add some oil.Load the system return lines must also be careful. When the load is reduced, the back will reduce the gas velocity, the speed is too low is not conducive to return oil. In order to ensure oil return under low load, the vertical double suction riser pipe can be used. Compressor oil return is not conducive to frequent starts. Continuous operation time is very short because the compressor stopped, and returned too late to form a stable tracheal high-speed air flow, oil can only stay in the pipeline. Return less than Ben oil, compressor will be short of oil. The shorter operation time, longer pipelines, more complex systems, back to the oil problem is more prominent. For the safety switch is not closed hydraulic compressor (including the scroll compressor and rotary compressor) and some semi-hermetic compressors), damage caused by frequent starting is more and more. Compressor maintenance is equally important. Defrost when the evaporator temperature increases, the oil viscosity decreases, easy flow. After the defrost cycle, refrigerant velocity, the oil will stay focused on return to the compressor. Therefore, the defrost cycle of the frequency and duration of each also need to be carefully set to avoid large fluctuations in oil or oil strike.Back when the refrigerant gas leakage of more speed will decrease, the speed is too low will cause oil pipe stuck in the back way, you can not quickly return to the compressor. Within the shell back to the compressor oil does not mean back to the crankcase. Crank chamber with the principle of negative pressure compressor oil return, if the piston due to wear caused by leaks, crankcase pressure rise, oil return check valve automatically closes the role of pressure difference, from the return pipe to return the oil to remain in motor chamber, unable to enter the crankcase, which is the return to the oil issue, the return of oil starvation will cause the same problem. In addition to wear such an incident。

化学工业中英文对照外文翻译文献

中英文对照外文翻译(文档含英文原文和中文翻译)译文：化学工业1. 化学工业的定义在本世纪初，定义出化学工艺制品的构成是不难的，因为那时制造出来的化学产品很有限，例如，强碱、硫酸溶液。

现在，千上万的化学品从天然材料中提炼出来，例如原油（某些领域）被加工成很多中间产品，可以作为消费品，或着转变成消费品。

困难是在于裁决那一部分的过程属于化学工业领域，举个例子来阐释这种情况，乳化油漆可以含有聚合物（聚乙烯树脂）/聚脂（乙烯基醋酸纤维）。

很明显的，人造聚乙烯树脂（或醋酸纤维）和它们的聚合物都是化工产品。

然而，如果油漆的合成和配制中含有聚脂，它是由多种化工加工产生的副产品，那它是属于化学工业产品还是装饰工业产品呢？办公多样化和各个工业领域的相似性造成的，是由于没有给化学工业简单定义。

相反，每一个办公个体搜集和出版关于工业生产的数据，将会给那些化工生产过程一个简单的定义。

在比较那些不同来源的统计信息的时候，这是需要铭记于心的。

2. 化学工业的需要化学工业与许多原材料的加工有密切关系。

如原油，首先要变成化工中间产品，然后被加工成各种各样的其他化工产品。

这些产品经常被用来生产消费产品，使得我们的生活更加舒适，或者在另外一些领域比如制药方面，用于保持我们身体健康。

每一个阶段产生的价值都被加入到产品中，而且它提供的这些附加价值远远超过了原材料价值和制造加工过程的成本，这样过程中就产生了利润。

这也是化学工业的目的所在。

在书中提出这样一个问题可能会很奇怪：“我们需要化学工业么。

”然而，如果尝试去回答这个问题就会得出：（1）化学工业活动的领域很广泛（2）它影响我们的日常生活（3）社会很需要化学工业我们的话题是回答这个问题化学工业对我们的贡献。

这些需要包括什么呢？新鲜的食物（和饮料）和健康是主要的。

其它我们考虑的还有服饰，住房，娱乐及交通运输。

1.食物。

化学工业对食物生产的主要贡献至少体现在三个方面。

首先，生产大量可用化肥代替作物生长需要的自然化肥（如氮、磷、钾），促使现代农业增产。

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