化学专业英语写作-第五章
化工学科英语作文模板
化工学科英语作文模板英文回答：Chemical Engineering: A Multidisciplinary Field with Wide-Ranging Applications。
Chemical engineering is a branch of engineering that deals with the application of science and mathematics to the design, construction, and operation of chemical plants and processes. The discipline encompasses a wide range of topics, including thermodynamics, fluid mechanics, heat and mass transfer, process control, and chemical reaction engineering.Chemical engineers work in a variety of settings, including chemical plants, pharmaceutical companies, food processing facilities, and environmental protection agencies. They are responsible for designing and operating processes that produce a wide range of products, including chemicals, pharmaceuticals, plastics, and fuels. They alsowork to develop and improve processes that are more efficient, less polluting, and safer.Chemical engineering is a rapidly growing field, as the demand for chemicals and other products continues to increase. In addition, the need for sustainable and environmentally friendly processes is driving the development of new technologies and processes in the field.Key Features of Chemical Engineering。
应用化学专业英语第五单元The Periodic Table
应用化学专业英语第五单元The PeriodicTable周期表是化学中一个重要的工具，它以一种有序的方式组织了所有已知的化学元素。
它是由俄罗斯化学家德米特里·门捷列夫于1869年发表的。
周期表通过将元素按照原子序数从小到大的顺序排列，并将具有相似化学性质的元素放在同一列中，使得科学家能够更好地理解和研究元素之间的关系和属性。
周期表的组织方式使得人们可以很容易地获取元素的基本信息。
每个元素都有一个原子序数，用来表示元素在周期表中的位置。
原子序数越大，元素的原子量也越大。
原子序数还代表着元素在元素周期表中的电子结构。
元素周期表还给出了每个元素的原子量、原子半径、电负性等重要数据。
这些数据对于理解元素的性质和反应非常重要。
周期表将元素划分为若干个不同的区域。
最常见的是主族元素和过渡元素。
主族元素包括位于周期表的左侧和右侧的元素，它们通常具有相似的化学性质。
过渡元素则是位于周期表中间部分的元素，它们具有不同的化学性质。
周期表还包含了稀土元素和放射性元素等特殊分类。
周期表的排列方式基于元素的原子结构和周期性规律。
元素周期表中水平的行被称为周期，垂直的列称为族。
元素周期表中的元素是按照原子序数递增的顺序排列的，每个周期都包含了一种新的元素。
这种排列方式揭示了许多周期性规律，例如，元素性质的周期性重复以及原子半径和电负性等特性的变化规律。
周期表的发展对于化学研究和工业应用都有着极其重要的意义。
科学家能够通过研究周期表中的元素，预测和设计新的化合物和材料。
周期表的使用还有助于解释许多化学现象和反应的原理。
周期表中的元素被广泛应用于制药、材料科学、环境保护等领域。
总之，周期表是化学中不可或缺的工具。
它通过以系统和有序的方式组织化学元素，帮助科学家更好地理解元素之间的关系和性质。
周期表提供了元素的基本信息和重要数据，为化学研究和应用提供了重要的参考。
周期表的发展对于推动化学领域的进步起到了重要的推动作用。
化工原理专业英语课文翻译第五单元阅读材料.
本文由hufei0419贡献化学工业主要行业国税发化工行业需要，如011和天然气，石灰石和盐天然原料人数较少和转换（通过化学处理或化学反应）他们把几千年的化学中间体。
正如我们已经看到，这些都是再转换到终端或消费者的产品。
这15 11llportant指出，增加值15在每一个阶段，这个过程和最终产品的价值，可能有有哪些在开始使用的原料很多次。
显然，在价值提升附加在每一个阶段必须超过15加工成本ifthe公司为实现其活动的利润。
主要行业有化工行业国税发：。
石化产品。
氯碱一alkaliproducts 。
聚合物。
Sulphuricacid（sulphurindustry）。
染料。
Ammoniaandfertilizers（nitrogenindustry）。
农用化工产品。
Phosphoricacidandphosphates 。
制药（phosphorusindustry）石化行业提供了关键中间体或积木（从011和天然气提取），如乙烯，丙烯，苯，甲苯，这些都是一个巨大的有机化工工业的范围，这是在生产合成的出发点下游加工国税发国税发在其他行业的一些上市的关键中间体。
15对聚合物部门的主要使用者ofpetrochemical 中间体和消耗几乎一半的有机化工原料所生产的总产出。
它包括塑料，合成纤维，橡胶，合成橡胶和粘合剂，它是与他们的特殊新材料，往往小说，物业，对有机化工行业1950年至1970年爆发性增长带来了巨大的需求。
虽然染料行业15比前两个更小，它已与他们紧密的联系。
这是由于传统的染料，这对于棉花，羊毛天然纤维细，分别为尼龙和聚酯像新的合成纤维完全不合适的。
的研究和技术部门内的大量工作造成了惊人的颜色多种，其中15个可用的现代服装。
随着一药品和植物保护剂（农药），染料的精细化学品的例子，我。
é。
在相对较小的化学品生产的吨位是用于高纯度和高价值的单位重量。
近年来，农用化学品（农药），以及制药业，有constifuted一个化工行业，我bluechip部门。
专业英语Introduction of General Chemistry
nonmetal ['non'metl] n.非金属（元素）
formula [ˈfɔ:mjələ] n.公式
product ['prodakt] n.产品，产物
reactant [riˈæktənt] n.反应物
symbol [simbal] n.符号，记号，象征
balance [ˈbæləns] n.秤，天平，平衡
商洛学院化学工程与现代材料学院 化学专业英语多媒体课件
化学专业英语
Professional English of Chemistry
Lesson 5 Introduction of GenExpressions
chemistry [kemistri] n.化学 matter [ˈmætə(r)] n.物质，实质 substance [ˈsʌbstəns] n.物质，实质，主旨 reactive [ri(i)'asktiv] adj.反应的，起反作 用的 decompose [.diikam‘pauz] v.分解 decomposition [dikomp‘zijan] n.分解 element [elimant] n.元素 solution [səˈlu:ʃn] n.溶液 aqueous [ˈeɪkwiəs] adj.水的，水成的 proton [prauton] n.质子 compound [ˈkɒmpaʊnd] n.化合物 phase [feiz] n.相 nucleus ['njuiklias] n.核子 electron [ɪˈlektrɒn] n.电子 component [kəmˈpəʊnənt] n.成分
Properties that involve substances changing into other substances are called chemical properties. The changes are called chemical changes or chemical reactions. Substances that react rapidly with many other substances are said to be reactive. Reactions in which substances combine to form more complex substances are called combination reactions and reactions in which substances break down (decompose) into simpler substances are called decomposition reactions.
化学专业英语unit.5
*
YANGTZE NORMAL UNIVERSITY
3） Anions containing hydrogen（含氢阴离 子）：hydrogen + 去掉氢的离子名称 例：HCO3-：hydrogen carbonate ion
YANGTZE NORMAL UNIVERSITY
3. Names of Acids（酸的命名）： 酸根离子中非氧元素名称的词干+ -ic acid
YANGTZE NORMAL UNIVERSITY
Nomenclature of Inorganic Compounds （无机化合物命名法） 1. Names of Cations（阳离子的命名）
1） Monatomic Cations（单原子阳离子）： 元素名称 + ion
* 如果某元素能形成一种以上的阳离子，则 使用斯托克数字（Stock number）来表示其 所带电荷（只形成一种阳离子的不必用）。
YANGTZE NORMAL UNIVERSITY
5. Names of Salts（盐的命名）：
不带“ion”的阳离子名称 + 不带“ion”的 阴离子名称 * 阳离子的电荷数用斯托克数字（Stock number） 来表示（只形成一种阳离子的元素不必用）. 例：CuCl：copper（I）chloride； CuCl2：copper（II）chloride； CuSO4：copper（II）sulfate； KClO4：potassium perchlorate
YANGTZE NORMAL UNIVERSITY
例:：
Na+：sodium ion；Ag+：silver ion；
Ca2+：calcium ion；
专业英语第五章写作详解演示文稿
2.3 摘要
• 摘要是以介绍论文主要内容为目的的小短文。 • 摘要一般位于正文之前，以十分简练的句子开门见山地说明论文的主
旨、观点，从而使读者可以在通读全文之前作出是否有必要通读全文 的判断。 • 摘要篇幅大小一般以不超过正文字数的5%为宜。
• 论文摘要应尽量将文中的内容和理解这些内容的主要要素写入 • 习惯性以“本文”、“本研究”等摘要的开头，是无信息的词语，
——我国科技期刊论文标题中文要求不超过20个汉字，外文一 般不超过10个实词。
• 英文标题一般是第一个单词的首字母大写，有时也可以是所 有实词首字母大写或全部大写。
第五页，共40页。
范例1：超高压对植物乳杆菌能量代谢影响的研究 Effects of high hydrostatic pressure on energy metabolism of
University, Tai'an 271018，China) (2 Key Laboratory of Quantitative Vegetation Ecology, Institute of
Botany, Chinese Academy of Sciences, Beijing 100093, China)
第十二页，共40页。
（3）表示研究结果与结论 The results indicated that… Our results confirm that… The study proves that… The results demonstrated that… The study reveals that… The conclusion is that… The results showed that… The results be summarized as follows We conclude：①… ②… ③… The comparison concludes that…
化学专业基础英语
distilled water alkali sodium hydroxide potassium hydroxide
pellet 球状 stick棒状 dilute 稀释, 稀释的 standardize 标定 ethyl alcohol 乙醇 ethanol 乙醇, 酒精 neutral 中性的
2、如何制备松香样品？
3、将松香溶解在什么溶剂中？ 4、对试剂和水的纯度有什么要求？
5、为何要配制硼砂缓冲溶液？
6、在电位法测定松香酸度的方法中，
如何更精确地确定等当点？
7、玻璃电极在无水介质中有可能脱水，
在使用玻璃电极时应如何避免这种情
况发生？
1、松香酸度的测定包含哪些方法？ 这些方法适用于测定什么类型的 松香？ Internal indicator method, and Potentiometric method.
purchaser seller phenolphthalein thymol thymol blue procedure
weigh 称量 Erlenmeyer flask 锥形瓶, 厄伦美氏(烧)瓶 dissolve 溶解 room temperature 室温 titrate，titration 滴定 persistent 稳定的 faint pink color 浅红色
The specimen shall be so prepared the same day on which the test is begun, in order to avoid changes in properties due to surface oxidation, which is very pronounced（显著的） on ground （ grind ，磨 ( 碎 ) ） rosin having a large surface area exposed to the air.
化学专业英语5-experiment
dropwise to a solution of 1,3-propanediol (29.9 g,
0.393 mol) and ethyl chloroformate (85.4 g, 0.786
mol) in 2L of THF at 0 oC over a period of 30 min.
Generally, an experimental section mainly consists
three parts, that is:
Chemicals (Materials), Synthesis (preparation),
and Characterization
Experimental
PVA is poly (vinyl alcohol) 聚乙烯醇
一、原材料的来源及准备(Chemicals or Materials)
Hale Waihona Puke All materials, such as potassium hexacyano-cobaltate (III) (K3Co(CN)6), zinc fluoride (ZnF2), zinc chloride (ZnCl2), zinc bromide (ZnBr2), zinc iodide (ZnI2) and tertiary butyl alcohol (tBuOH) were purchased from Aldrich and used without further purification.
一、原材料的来源及准备(Chemicals or Materials) 2. 直接购买的普通溶剂或辅助药品只需简单提及或略 过
化学专业英语第五版
化学专业英语第五版英文回答：Introduction.Chemistry is the study of matter and its properties, as well as the changes that matter undergoes. It is a vast and complex field that encompasses many different branches, including inorganic chemistry, organic chemistry, physical chemistry, analytical chemistry, and biochemistry.Chemistry is essential to our understanding of theworld around us. It plays a role in everything from thefood we eat to the clothes we wear to the medicines we take. Chemistry is also used in a wide variety of industries, including manufacturing, agriculture, and energy production.Importance of Chemistry.Chemistry is important for a number of reasons. First,it helps us to understand the world around us. By studying chemistry, we can learn about the composition of matter, the properties of different elements and compounds, and the changes that matter undergoes. This knowledge can help us to make informed decisions about the products we use and the activities we engage in.Second, chemistry is essential for the development of new technologies. Many of the technologies that we rely on today, such as computers, cell phones, and medical devices, would not be possible without chemistry. Chemistry is also used to develop new materials, such as plastics, ceramics, and composites. These materials are used in a wide variety of applications, from construction to transportation to medicine.Third, chemistry is important for the environment. Chemistry can help us to understand the impact of human activities on the environment and develop ways to reduce our impact. Chemistry is also used to develop new technologies that can help us to clean up pollution and protect the environment.Challenges in Chemistry.Chemistry is a challenging field, but it is also a rewarding one. There are many challenges that chemists face, including:The complexity of matter. Matter is made up of atoms and molecules, which are themselves made up of even smaller particles. Understanding the structure and properties of matter is a complex task.The vastness of chemistry. Chemistry is a vast field that encompasses many different branches. It is impossible for any one person to know everything about chemistry.The rapid pace of change. Chemistry is a rapidly changing field. New discoveries are being made all the time. Chemists must be able to keep up with the latest advancesin order to stay current in their field.Despite the challenges, chemistry is a fascinating andrewarding field. It is a field that is constantly evolving, and there is always something new to learn.中文回答：导言。
化学师范专业介绍英语作文
化学师范专业介绍英语作文Chemistry Education Major Introduction。
Chemistry education is a branch of chemistry that focuses on teaching and learning chemistry in schools. It is a field that combines the principles of chemistry with the theories of education to develop effective teaching methods and strategies for students of all ages. Students majoring in chemistry education not only study the core concepts of chemistry but also learn how to effectively communicate these concepts to others.In a chemistry education program, students will take courses in general chemistry, organic chemistry, physical chemistry, and analytical chemistry. They will also study education theory, curriculum development, and classroom management. Additionally, students will have the opportunity to participate in hands-on laboratory experiences and teaching practicums to gain practical teaching skills.One of the key goals of a chemistry education programis to prepare students to become effective chemistry teachers in middle schools, high schools, and colleges. Graduates of these programs are equipped with the knowledge and skills needed to create engaging and interactive lessons that help students understand and appreciate the concepts of chemistry. They are also trained to effectively assess student learning and provide feedback to help students improve their understanding of chemistry.In addition to teaching, graduates of chemistry education programs may also pursue careers in curriculum development, educational research, or science outreach. They may work for educational organizations, government agencies, or non-profit organizations to develop educational resources, conduct research on effective teaching practices, or promote science education in the community.Overall, a degree in chemistry education opens up a wide range of career opportunities for students who arepassionate about both chemistry and education. By combining their knowledge of chemistry with their teaching skills, graduates of these programs play a crucial role ininspiring the next generation of scientists and helping students develop a deeper understanding of the world around them.。
应用化学英文作文
应用化学英文作文英文：As an applied chemist, my job involves using chemical principles and techniques to solve practical problems in various industries. This can include developing new materials for use in construction, improving the efficiency of industrial processes, and ensuring the safety andquality of consumer products.One example of how I have applied chemistry in my work is in the development of a new type of insulation material for buildings. By using my knowledge of the properties of different chemicals and their reactions, I was able to create a material that is both highly effective at insulating and environmentally friendly.Another example is in my work with a pharmaceutical company. By applying my understanding of how drugs interact with the body, I was able to help develop a new medicationthat is more effective and has fewer side effects than previous treatments.Overall, being an applied chemist requires a strong foundation in chemical principles, as well as the ability to think creatively and apply that knowledge to real-world problems.中文：作为一名应用化学家，我的工作涉及使用化学原理和技术来解决各种行业中的实际问题。
化学专业英语写作-第五章
• 1.4.2 没有理由地改变主语或宾语的数 • 病句：(1) If one tries hard, they can pass the entrance examination. • (2) He carefully wiped each of the instruments and put them away.
6
• 1.2 把应该密接的思想分开来
• 病 句 ： Mr. Wang was a wonderful electrical engineer, He was also a mathematical genius. At first he worked in a telegraph office and had to leave because he became deaf. Finally he retired to Tianjin, and lived alone. • 除了给儿童或初学外文的人写作时，需要简 短的句子外，一般在写作上很少都是简单句— —主+谓+宾一类的格式，科学论文也不例外， 一联串的短句，犹如一架不停开放的机关抢， 声音单调而机械，使人看了神经紧张，因而在 文字上不能起到吸引读者的作用，上文可改写：
第五章 科技英语中常用修辞学
1
•
文章是由段落组成的，段落又是由句子组成 的，句子是表达思想感情的最小语言单位，因 此要把文章写好，就必须把句子造好，每个段 落写好，写好段落和要造好句子就必须掌握四 大要素：统一性，连贯性，强势性和简洁性。
2
1．统一性(unity) 统一性(unity)
• 句子的统一性包括每一个句话都有一个明确 的中心思想，一句话只允许讲述一个中心思想， 一句中若出现两个或两个以上相关连的思想时， 我们要判断哪个是主要思想，哪个是从属思想？ 分别以主句和从句将思想表达出来。如果两个 思想重要性相等，又密切关连，则用并列连接 词，写出并列句，如果两个或更多的思想互不 关连，则用两个或更多的句子来表达，否则将 两个以上互不关联的概念放入一个句子，时而 以甲为对象，时而以乙作对象，变得语无论次， 就破坏了句子的统一性。
化学专业英语第五章
syn elimination
2. Elimination Reactions
anti elimination
or
E1: unimolecular elimination
Elimination Reactions
E2 : bimolecular elimination
3. substitution reaction:
5. rearrangement Reaction Rearrangement reactions occur when one starting material forms one product with a different arrangement of atoms and bonds. In a rearrangement reaction, the atoms or groups present in the reactant are connected in a different fashion in the product. The reactant and product can have the same empirical formula, or different numbers and types of atoms.
6. oxidation-reduction Reaction The term oxidation in organic chemistry differs from that in inorganic chemistry. Oxidation in organic chemistry usually implies removal of hydrogen or replacement of a hydrogen atom linked to carbon with a more electronegative atom such as oxygen.
化工专业英语 unit 5
The industry may well see increased consolidation as companies
swap plants to achieve better economies of scale or better market position in specific products. This could leave an industry with far fewer players but with a better balance of supply and demand and better profitability. The industry will move more serving the rest of the chemical industry and less to serving the farming industry.
The basic chemical industry is now facing one of biggest challenges in its history. The main consumers of the industry’s key products—the agriculture industry –has stopped growing and is severely cutting back its demand for fertilizers. western farmers have producing too much food and governments have been cutting its cutting subsidies, with the result that less land is being farmed and less fertilizer used. Environmental concerns about the effects of excessive fertilizer run-off have also reduced demand for fertilizers.
化学专业英语第五章
1第五章专业英语阅读Unit 1 Unit OperationsLesson 1 Classification of Unit OperationsFluid flowThis concerns the principles that determine the flow or transportation of any fluid from one point to another.Turbulent 混乱的Laminar 流线的EvaporationThis is a special case of heat transfer, which deals with the evaporation of a volatile solvent such as water from a nonvolatile solute such as salt or any other material in solution.DryingIn this operation volatile liquids, usually water, are removed from solid materialsAbsorptionIn this process a component is removed from a gas stream by treatment with a liquid.Liquid-liquid extractionIn this case a solute in a liquid solution is removed by contacting with another liquid solvent which is relatively immiscible(不混溶的) with the solution.Liquid-solid leaching(浸提)This involves treating a finely divided solid with a liquid that dissolves out and removes a solute contained in the solid.CrystallizationThis concerns the removal of a solute such as a salt from a solution by precipitating(沉淀) the solute from the solution.Mechanical physical separationThese involves separation of solids, liquids, or gases by mechanical means, such as filtration, settling, and size reduction, which are often classified as separate unit operations.Heat transferThis unit operation deals with the principles that govern accumulation and transfer of heat and energy from one place to another.Fractional distillationFractional distillation is the separation of a mixture of compounds by their boiling point, by heating to high enough temperatures.Industrial uses of Fractional Distillation ——Oil refineryThe most important industrial application of fractional distillation is the distillation of crude oil.The process is similar in principle to the laboratory method described above except for scale,continuous feed and operation,and the fact that crude oil has many different compounds mixed together.The fractionating column has outlets at regular intervals up the column which allow the different fractions to run out at different temperatures,with the highly volatile gases coming out the topmost outlet graduating to the less volatile road tar,(bitumen 沥青)coming out at the bottom.CrystallizationCrystallization is a technique which chemists use to purify solid compounds.It is one of the fundamental procedures each chemist must master to become proficient in the laboratory.Crystallization is based on the principles of solubility: compounds(solutes)tend to be more soluble in hot liquids(solvents)than they are in cold liquids.If a saturated hot solution is allowed to cool,the solute is no longer soluble in the solvent and forms crystals of pure compound.Impurities are excluded from the growing crystals and the pure solid crystals can be separated from the dissolved impurities by filtration.Reaction EngineeringReactor Types1 Stirred tank reactorA batch stirred tank reactor is the simplest type of reactor. It is composed of a reactor and a mixer such as a stirrer, a turbine wing or a propeller. The batch stirred tank reactor is illustrated below:The batch system is generally suitable for the production of rather small amounts of chemicals.A continuous stirred tank reactor is shown below.The continuous stirred tank reactor is more efficient than a batch stirred tank reactor but the equipment is slightly more complicated.2 Tubular ReactorTubular reactors are generally used for gaseous reactions, but are also suitable for some liquid-phase reactions.If high heat-transfer rates are required, small-diameter tubes are used to increase the surface area to volume ratio.Several tubes may be arranged in parallel, connected to a manifold(多支管) or fitted into a tube sheet in a similar arrangement to a shell and tube heat exchanger.For high-temperature reactions the tubes may be arranged in a furnace. 3Fluidized bed ReactorA fluidized bed reactor(FBR)is a type of reactor device that can be used to carry out a variety of multiphase chemical reactions. In this type of reactor,a fluid(gas or liquid) is passed through a granular solid material (usually a catalyst possibly shaped as tiny spheres)at high enough velocities to suspend the solid and cause it to behave as though it were a fluid.This process,known as fluidization,imparts many important advantages to the FBR.As a result,the fluidized bed reactor is now used in many industrial applications.Membrane separationThis process involves the diffusion of a solute from a liquid or gas through a semipermeable membrane barrier to another fluid.Nanofiltration(NF)Ultrafiltration (UF)Microfiltration (MF)BiochemistryBiochemistry is the study of the chemical processes in living organisms. It deals with the structure and function of cellular components, such as proteins, carbohydrates, lipids, nucleic acids, and other biomolecules.Carbohydrates are the primary source of food energy for most living systems. Carbohydrates are produced from CO2 and H2O during photosynthesis and are therefore the end products of the process by which plants capture the energy in sunlight.Theαandβanomers of glucose. Note the position of the hydroxyl group (red or green) on the anomeric carbon relative to the CH2OH group bound to carbon 5: they are either on the opposite sides (α), or the same side (β)Lipids, on the other hand, are defined on the basis of their physical properties.Any molecule in a biological system that is soluble in nonpolar solvents is classified as a lipid.The lipid known as cholesterol, for example, is virtually insoluble in water, but it is soluble in a variety of nonpolar solvents including the nonpolar region between the inner and outer surfaces of a membrane.DNAThe biochemistry of cell metabolism and the endocrine(内分泌) system has been extensively described.Other areas of biochemistry include the genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction.DNA structureDeoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses.The main role of DNA molecules is the long-term storage of information. Chemically, DNA consists of two long polymers of simple units called nucleotides(核苷酸), with backbones made of sugars and phosphate groups joined by ester bonds.ProteinA protein is a biological polymer comprising (由…构成；包含)numerous amino acids linked recursively(递进) through peptide bonds between a carboxyl group and an amino group of adjacent 相邻amino acids to form a long chain with the defining side group of each amino acid protruding from it.The sequence of amino acids in a protein is defined by a gene and encoded in the genetic code, which selects protein components from a set of 20 “standard” amino acids.。
化学化工专业英语
1 CHEMISTRY AND CHEMISTWithout chemistry our lives would beunrecognisable, for chemistry is at work all aroundus. Think what life would be like without chemistry- there would be no plastics, no electricity and noprotective paints for our homes. There would be no synthetic fibres to clothe us and no fertilisers to help us produce enough food. We wouldn‟t be able to travel because there would be no metal, rubber or fuel for cars, ships and aeroplane. Our lives would be changed considerably without telephones, radio, television or computers, all of which depend on chemistry for the manufacture of their parts. Life expectancy would be much lower, too, as there would be no drugs to fight disease.Chemistry is at the forefront of scientific adventure, and you could make your own contribution to the rapidly expanding technology we are enjoying. Take some of the recent academic research: computer graphics allow us to predict whether small molecules will fit into or react with larger ones - this could lead to a whole new generation of drugs to control disease; chemists are also studying the use of chemicals to trap the sun‟s energy and to purify sea water; they are also investigating the possibility of using new ceramic materials to replace metals which can corrode.Biotechnology is helping us to develop new sources of food and new ways of producing fuel, as well as producing new remedies for the sick. As the computer helps us to predict and interpret results from the test tube, the speed, accuracy and quality of results is rapidly increasing - all to the benefit of product development.It is the job of chemists to provide us with new materials to take us into the next century, and by pursuing the subject, you could make your positive contribution to society.Here are some good reasons for choosing chemistry as a career.Firstly, if you have an interest in the chemical sciences, you can probably imagine taking some responsibility for the development of new technology. New ideas and materials are constantly being used in technology to improve the society in which we live. You could work in a field where research and innovation are of primary importance to standards of living, so you could see the practical results of your work in every day use.Secondly, chemistry offers many career opportunities, whether working in a public service such as a water treatment plant, or high level research and development in industry. Your chemistry-based skills and experience can be used, not only in many different areas within the chemical industry, but also as the basis for a more general career in business.1 As a qualification, chemistry is highly regarded as a sound basis for employment.You should remember that, as the society we live in becomes more technically advanced, the need for suitably qualified chemists will also increase. Although chemistry stands as a subject in its own right, it acts as the bond between physics and biology. Thus, by entering the world of chemistry you will be equipping yourself to play a leading role in the complex world of tomorrow.Chemistry gives you an excellent training for many jobs, both scientific and non-scientific. To be successful in the subject you need to be able to think logically, and be creative, numerate, and analytical. These skills are much sought after in many walks of life, and would enable you to pursue a career in, say, computing and finance, as well as careers which use your chemistry directly.Here is a brief outline of some of the fields chemists work in:Many are employed in the wealth-creating manufacturing industries - not just oil, chemical and mining companies, but also in ceramics, electronics and fibres. Many others are in consumer based industries such as food, paper and brewing; or in service industriessuch as transport, health and water treatment.In manufacturing and service industries, chemists work in Research and Development to improve and develop new products, or in Quality Control, where they make sure that the public receives products of a consistently high standard.Chemists in the public sector deal with matters of public concern such as food preservation, pollution control, defence, and nuclear energy. The National Health Service also needs chemists, as do the teaching profess ion and the Government‟s research and advisory establishments.Nowadays, chemists are also found in such diverse areas as finance, law and politics, retailing, computing and purchasing. Chemists make good managers, and they can put their specialist knowledge to work as consultants or technical authors. Agricultural scientist, conservationist, doctor, geologist, meteorologist, pharmacist, vet ... the list of jobs where a qualification in chemistry is considered essential is endless. So even if you are unsure about what career you want to follow eventually, you can still study chemistry and know that you‟re keeping your options open.What Do Chemistry Graduates Do?Demand for chemists is high, and over the last decade opportunities for chemistry graduates have been increasing. This is a trend that is likely to continue. Chemistry graduates are increasingly sought after to work in pharmaceutical, oil, chemical, engineering, textile and metal companies, but the range of opportunities also spans the food industry, nuclear fuels, glass and ceramics, optical and photographic industries, hospitals and the automotive industry. Many graduates begin in scientific research, development and design, but over the years, about half change, into fields such as sales, quality control, management, or consultancy. Within the commercial world it is recognised that, because of the general training implicit in a chemistry course, chemistry graduates are particularly adaptable and analytical - making them attractive to a very broad spectrum of employers. There has been a growth of opportunity for good chemistry graduates to move into the financial world, particularly in accountancy, retail stores, and computer software houses.（Summarized from: A brief of the Royal Society of Chemistry,1992）2 NOMENCLATURE OF INORGANICCOMPOUNDSNaming elementsThe term element refers to a pure substance with atoms all of a single kind. At present 107 chemical elements are known. For most elements the symbol is simply the abbreviated form of the English name consisting of one or two letters, for example:oxygen = O nitrogen = N magnesium = MgSome elements, which have been known for a long time, have symbols based on their Latin names, for example:iron = Fe (ferrum) copper = Cu (cuprum) lead = Pb (Plumbum)A few elements have symbols based on the Latin name of one of their compounds, the elements themselves having been discovered only in relatively recent times1, for example: sodium = Na (natrium = sodium carbonate)potassium = K (kalium = potassium carbonate)A listing of some common elements may be found in Table 1.Naming Metal Oxides, Bases and SaltsA compound is a combination of positive and negative ions in the proper ratio to give a balanced charge and the name of the compound follows from names of the ions, for example, NaCl, is sodium chloride; Al(OH)3is aluminium hydroxide; FeBr2is iron (II) bromide or ferrous bromide; Ca(OAc)2is calcium acetate; Cr2(SO4)3is chromium (III) sulphate or chromic sulphate, and so on. Table 3 gives some examples of the naming of metal compounds. The name of the negative ion will need to be obtained from Table 2.Negative ions, anions, may be monatomic or polyatomic. All monatomic anions have names ending with -ide. Two polyatomic anions which also have names ending with -ide are the hydroxide ion, OH-, and the cyanide ion, CN-.Many polyatomic anions contain oxygen in addition to another element. The number of oxygen atoms in such oxyanions is denoted by the use of the suffixes -ite and -ate, meaning fewer and more oxygen atoms, respectively. In cases where it is necessary to denote more than two oxyanions of the same element, the prefixes hypo- and per-, meaning still fewer and still more oxygen atoms, respectively, may be used, for example,hypochlorite ClO-Chlorite ClO2-chlorate ClO3-perchlorate ClO4-Naming Nonmetal OxidesThe older system of naming and one still widely used employs Greek prefixes for both the number of oxygen atoms and that of the other element in the compound 2. The prefixes used are (1) mono-, sometimes reduced to mon-, (2) di-, (3) tri-, (4) tetra-, (5) penta-, (6) hexa-, (7) hepta-, (8) octa-, (9) nona- and (10) deca-. Generally the letter a is omitted from the prefix (from tetra on ) when naming a nonmetal oxide and often mono- is omitted from the name altogether.The Stock system is also used with nonmetal oxides. Here the Roman numeral refers to the oxidation state of the element other than oxygen.In either system, the element other than oxygen is named first, the full name being used, followed by oxide 3. Table 4 shows some examples.Naming AcidsAcid names may be obtained directly from a knowledge of Table 2 by changing the name of the acid ion (the negative ion ) in the Table 2 as follows:The Ion in Table 2Corresponding Acid-ate-ic-ite-ous-ide-icExamples are:Acid Ion Acidacetate acetic acidperchlorate perchloric acidbromide hydrobromic acidcyanide hydrocyanic acidThere are a few cases where the name of the acid is changed slightly from that of the acid radical; for example, H2SO4 is sulphuric acid rather than sulphic acid. Similarly, H3PO4 is phosphoric acid rather than phosphic acid.Naming Acid and Basic Salt and Mixed SaltsA salt containing acidic hydrogen is termed an acid salt.A way of naming these salts is to call Na 2HPO4disodiumhydrogen phosphate and NaH2PO4sodium dihydrogenphosphate. Historically, the prefix bi- has been used innaming some acid salts; in industry, for example, NaHCO3 iscalled sodium bicarbonate and Ca(HSO3)2 calcium bisulphite.Bi(OH)2NO3, a basic salt, would be called bismuthdihydroxynitrate. NaKSO4, a mixed salt, would be calledsodium potassium sulphate.3 NOMENCLATURE OF ORGANIC COMPOUNDSA complete discussion of definitive rules of organic nomenclature would require more space than can be allotted in this text. We will survey some of the more common nomenclature rules, both IUPAC and trivial.AlkanesThe names for the first twenty continuous-chain alkanes are listed in Table 1.Alkenes and AlkynesUnbranched hydrocarbons having one double bond are named in the IUPAC system by replacing the ending -ane of the alkane name with -ene. If there are two or more double bonds, the ending is -adiene, -atriene, etc.Unbranched hydrocarbons having one triple bond are named by replacing the ending -ane of the alkane name with -yne. If there are two or more triple bonds, the ending is -adiyne, -atriyne etc. Table 2 shows names for some alkyl groups, alkanes, alkenes and alkynes.The PrefixesIn the IUPAC system, alkyl and aryl substituents and many functional groups are named as prefixes on the parent (for example, iodomethane). Some common functional groups named as prefixes are listed in Table 3.In simple compounds, the prefixes di-, tri-, tetra-, penta-, hexa-, etc. are used to indicate the number of times a substituent is found in the structure: e.g., dimethylamine for (CH3)2NH or dichloromethane for CH2Cl2.In complex structures, the prefixes bis-, tris-, and tetrakis- are used: bis- means two of a kind; tris-, three of a kind; and tetrakis-, four of a kind. [(CH3)2N]2is bis(dimethylamino) and not di(dimethylamino).Nomenclature Priority of Functional GroupsIn naming a compound, the longest chain containing principal functional group is considered the parent. The parent is numbered from the principal functional group to the other end, the direction being chosen to give the lowest numbers to the substituents. The entire name of the structure is then composed of (1) the numbers of the positions of the substituts (and of the principal functional group, if necessary); (2) the names of the substituts;(3) the name of the parent.The various functional groups are ranked in priority as to which receives the suffix name and the lowest position number1.A list of these priorities is given in Table 4.*-CKetonesIn the systematic names for ketones, the -e of the parent alkane name is dropped and -one is added. A prefix number is used if necessary.In a complex structure, a ketone group my be named in IUPAC system with the prefix oxo-. (The prefix keto- is also sometimes encountered.)AlcoholsThe names of alcohols may be: (1) IUPAC; (2) trivial; or, occasionally, (3) conjunctive. IUPAC names are taken from the name of the alkane with the final -e changed to -ol. In the case of polyols, the prefix di-, tri- etc. is placed just before -ol, with the position numbers placed at the start of the name, if possible, such as, 1,4-cyclohexandiol. Names for some alkyl halides, ketones and alcohols are listed in Table 5.EthersEthers are usually named by using the names of attached alkyl or aryl groups followed by the word ether. (These are trivial names.) For example, diethyl ether.In more complex ethers, an alkoxy- prefix may be used. This is the IUPAC preference, such as 3-methoxyhexane. Sometimes the prefix- oxa- is used.AminesAmines are named in two principal ways: with -amine as the ending and with amino- as a prefix. Names for some ethers and amines can be found in Table 6.Carboxylic AcidsThere are four principal types of names for carboxylic acids: (1) IUPAC; (2)trivial;(3)carboxylic acid; and (4)conjunctive. Trivial names are commonly used.AldehydesAldehydes may be named by the IUPAC system or by trivial aldehyde names. In the IUPAC system, the -oic acid ending of the corresponding carboxylic acid is changed to -al, such as hexanal. In trivial names, the -ic or -oic ending is changed to -aldehyde, such as benzaldehyde. Table 7 gives a list of commonly encountered names for carboxylic acids and aldehydes.Esters and Salts of Carboxylic AcidsEsters and salts of carboxylic acids are named as two words in both systematic and trivial names. The first word of the name is the name of the substituent on the oxygen. The second word of the name is derived from the name of the parent carboxylic acid with the ending changed from -ic acid to -ate.AmidesIn both the IUPAC and trivial systems, an amide is named by dropping the -ic or -oic ending of the corresponding acid name and adding -amide, such as hexanamide (IUPAC) and acetamide (trivial).Acid AnhydridesAcid anhydrides are named from the names of the component acid or acids with the word acid dropped and the word anhydride added, such as benzoic anhydride.The names for some esters, amides and anhydrides are shown in Table 8.Acid HalidesAcid halides are named by changing the ending of the carboxylic acid name from -ic acid to -yl plus the name of the halide, such as acetyl chloride.Some names of aryl compounds and aryls are as follows:benzenephenylbenzylarylbenzoic acid4. Introduction to Chemistry Department of FloridaUniversityProgram of StudyThe Department of Chemistry offers programs of study leading to the M.S. and Ph.D. degrees. Students may elect studies in analytical, inorganic, organic, and physical chemistry. Specialty disciplines, such as chemical physics and quantum, bioorganic, polymer, radiation, and nuclear chemistry, are available within the four major areas.The M.S. and Ph.D. degree requirements include a course of study, attendance at and presentation of a series of seminars, and completion and defense of a research topic worthy of publication1. Candidates for the Ph.D. degree must also demonstrate a reading ability of at least one foreign language and show satisfactory performance on a qualifying examination. The M.S. degree is not a prerequisite for the Ph.D. degree. A nonthesisdegree program leading to the M.S.T. degree is offered for teachers.Students are encouraged to begin their research shortly afterselecting a research director, who is the chairman of the supervisorycommittee that guides the student through a graduate career.Research FacilitiesThe chemistry department occupies 111,000 square feet of space in four buildings: Leigh Hall, the Chemical Research Building, Bryant Hall, and the Nuclear Science Building. Plans for a 65,000-square-foot addition to Leigh Hall are being prepared. A new central science library is located near the chemistry facilities. The University library system holds more than 2.2 million volumes.The major instrumentation includes ultraviolet-visible, infrared, fluorescence, Roman, nuclear magnetic resonance, electron spin resonance, X-ray, ESCA, and mass spectrometers. Many are equipped with temperature-control and Fourier-transform attachments, and some have laser sources. Data-storage and data-acquiring minicomputers are interfaced to some of the instruments, such as the recently constructed quadrupole resonance mass spectrometer. The chemistry department has V AX-11/780 and V AX-11/750 computers as well as multiple terminals connected to IBM machines in the main computer centre on campus.The departmental technical services include two well-equipped stockrooms and glassblowing, electronics, and machine shops to assist in equipment design, fabrication, and maintenance.Financial AidMost graduate students are given financial support in the form of teachingand research assistantships. Stipends range from $9400 - 11,000 for the1986-87 calendar year. State residents and assistantship holders pay in-statefees of about $1400 per calendar year. A limited number of full orsupplemental fellowships are available for superior candidates.Cost of StudyIn 1985-86, in-state students paid a registration fee of $48.62, per credit hour for each semester, out-of-state students paid an additional $ 94.50 ($ 143.12 per credit hour each semester). A small increase in fees is expected for 1986-87.5 ENVIRONMENTAL POLLUTIONWith the coming of the Industrial Revolution the environmentalpollution increased alarmingly. Pollution can be defined as an undesirablechange in the physical, chemical, or biological characteristics of the air, water,or land that can harmfully affect health, survival, or activities of humans orother living organisms. There are four major forms of pollution - waste onland, water pollution (both the sea and inland waters), pollution of the atmosphere and pollution by noise.Land can be polluted by many materials. There are two major types of pollutants: degradable and nondegradable. Examples of degradable pollutantsare DDT and radioactive materials. DDT can decompose slowly buteventually are either broken down completely or reduced to harmless levels. For example, it typically takes about 4 years for DDT in soil to be decomposed to 25 percent of the original level applied. Some radioactive materials that give off harmful radiation, such as iodine-131, decay to harmless pollutants. Others, such as plutonium-239 produced by nuclear power plants, remains at harmful levels for thousands to hundreds of thousands of years.Nondegradable pollutants are not broken down by natural processes. Examples of nondegradable pollutants are mercury, lead and some of their compounds and some plastics. Nondegradable pollutants must be either prevented from entering the air, water, and soil or kept below harmful levels by removal from the environment.Water pollution is found in many forms. It is contamination of water with city sewage and factory wastes; the runoff of fertiliser and manure from farms and feed lots; sudsy streams; sediment washed from the land as a result of storms, farming, construction and mining; radioactive discharge from nuclear power plants; heated water from power and industrial plants; plastic globules floating in the world‟s oceans; and female sex hormones entering water supplies through the urine of women taking birth control pills.Even though scientists have developed highly sensitive measuringinstruments, determining water quality is very difficult. There are a largenumber of interacting chemicals in water, many of them only in trace amounts.About 30,000 chemicals are now in commercial production, and each yearabout 1,000 new chemicals are added. Sooner or later most chemicals end up in rivers, lakes, and oceans. In addition, different organisms have different ranges of tolerance and threshold levels for various pollutants. To complicate matters even further, while some pollutants are either diluted to harmless levels in water or broken down to harmless forms by decomposers and natural processes, others (such as DDT, some radioactive materials, and some mercury compounds) are biologically concentrated in various organisms1.Air pollution is normally defined as air that contains one or more chemicals in high enough concentrations to harm humans, other animals, vegetation, or materials. There are two major types of air pollutants. A primary air pollutant is a chemical added directly to the air that occurs in a harmful concentration. It can be a natural air component, such as carbon dioxide, that rises above its normal concentration, or something not usually found in the air,such as a lead compound. A secondary air pollutant is a harmful chemical formed in the atmosphere through a chemical reaction among air components.We normally associate air pollution with smokestacks and cars, but volcanoes, forest fires, dust storms, marshes, oceans, and plants also add to the air chemicals we consider pollutants. Since these natural inputs are usually widely dispersed throughout the world, they normally don‟t build up to harmful levels. And when they do, as in the case of volcanic eruptions, they are usually taken care of by natural weather and chemical cycles2.As more people live closer together, and as they use machines to produce leisure, they find that their leisure, and even their working hours, become spoilt by a byproduct of their machines – namely, noise,The technical difficulties to control noise often arise from the subjective-objective nature of the problem. You can define the excessive speed of a motor-car in terms of a pointer reading on a speedometer. But can you define excessive noise in the same way? You find that with any existing simple “noise-meter”, vehicles which are judged to be equally noisy may show considerable difference on the meter.Though the ideal cure for noise is to stop it at its source, thismay in many cases be impossible. The next remedy is to absorb iton its way to the ear. It is true that the overwhelming majority ofnoise problems are best resolved by effecting a reduction in thesound pressure level at the receiver. Soft taped music in restaurantstends to mask the clatter of crockery and the conversation at thenext table. Fan noise has been used in telephone booths to maskspeech interference from adjacent booths. Usually, the problem is how to reduce the sound pressure level, either at source or on the transmission path.6 ANALYTICAL INSTRUMENT MARKETThe market for analytical instruments is showing a strength only dreamed about as little as five years ago. Driven by the need for greater chemicalanalysis coming from quality control and government regulation, arobust export market, and new and increasingly sophisticatedtechniques, sales are increasing rapidly1.The analytical instrument business' worldwides sales arenearly double their value of five years ago, reaching $ 4.1 billion in1987. Such growth is in stark contrast to the doldrums of severalyears ago when economic recession held back sales growth to littleor nothing. In recent years, the instrumentation market hasrecovered, growing at nearly 9% per year, and it‟s expected t o continue at this rate at least until the 1990. With sales increases exceeding inflation, the industry has seen the real growth demonstrating the important role of chemical instrumentation in areas such as research and development, manufacturing, defense, and the environment in a technologically advancingworld2.Chromatography is the fastest-growing area, comprising 40%, or $ 1.5billion, in 1987 world sales. Chromatographic methods are used extensively inindustrial labs, which purchase about 70% of the devices made, for separation,purification, and analysis. One of the biggest words in all forms of chromatography is “biocompatibility.” Biocompatible instruments are designed to have chemically inert, corrosion-resistant surfaces in contact with the biological samples.Gas Chromatography sales are growing at about the same rate as the instrument market.Some of the newest innovations in GC technology are the production of more instruments with high-efficiency, high-resolution capillaries and supercritical fluid capability.Despite having only a 3% share of the GC market, supercritical fluid chromatography (SFC) has attracted a great deal of attention since its introduction around 1985 and production of the first commercial instrument around 1986. SFC, which operates using asupercritical fluid as the mobile phase, bridgesthe gap between GC and HPLC. The use ofthese mobile phases allows for higherdiffusion rates and lower viscosities thanliquids, and a greater solvating powerthan gases.Another area showing tremendous growth is ion chromatography (IC). From growth levels of 30% per year in the U.S. and similar levels worldwide, the rate is expected to drop slightly but remain high at 25%. The popularity of IC has been enhanced through extending its applicability from inorganic systems to amino acids and other biological systems by the introduction of biocompatible instruments.Mass spectrometry (MS) sales have been growing about 12% annually. Sales have always been high, especially since MS is the principal detector in a number of hyphenated techniques such as GC-MS, MS-MS, LC-MS, and GC-MS accounts for about 60% of MS sales since it is used widely in drug and environmental testing. Innovations in interface technology such as inductively coupled plasma/MS, SFC/MS, and thermospray or particle beam interfaces for LC-MS have both advanced the technology and expanded the interest in applications. Recent MS instruments with automated sampling and computerized data analysis have added to the attractiveness of the technique for first time users.Spectroscopy accounts for half of all instrument sales and is the largest overall category of instruments, as the Alpert & Suftcliffe study shows. It can be broken down evenly into optical methods and electromagnetic, or nonoptical, spectroscopies. These categories include many individual high-cost items such as MS, nuclear magnetic resonance spectrometers, X-ray equipment, and electron microscopy and spectroscopy setups. Sales of spectroscopic instruments that are growing at or above the market rate include Fourier transform infrared (FTIR), Raman, plasma emission, and energy dispersive X-ray spectrometers. Others have matured and slowed down in growth, but may still hold a large share of the market.The future of analytical instrumentation does not appear to be without its new stars as there continue to be innovations and developments in existing technology. Among these are the introduction of FT Raman, IR dichroism, IR microscopy, and NMR imaging spectrometers. Hyphenated and automated apparatus are also appearing on the market more frequently. New analytical techniques like capillary electrophoresis, gel capillary electrophoresis, scanning tunneling microscopy for the imaging of conducting systems, atomic force microscopy for the imaging of biological systems, and other techniques for surface and materials analysis are already, or may soon be, appearing as commercialized instruments. And, if the chemical industry continues to do well in the next few years, so too will the sales of analytical instrumentation.The effect of alcohol have both medical and medicolegal implications. The estimationof alcohol in the blood or urine is relevant when the physician needs toknow whether it is responsible for the condition of the patient. From themedicolegal standpoint the alcohol level is relevant in cases of suddendeath, accidents while driving, and in cases when drunkenness is thedefense plea. The various factors in determining the time after ingestion showing maximum concentration and the quality of the alcohol are the weight of the subject,。
化学专业英文作文范文
化学专业英文作文范文英文：Chemistry is a fascinating subject that deals with the study of matter and its properties. As a chemistry major, I have learned about the different types of chemical reactions, the behavior of atoms and molecules, and the principles of chemical bonding. I have also gainedpractical experience in the laboratory, conducting experiments and analyzing data.One of the most interesting topics in chemistry is organic chemistry, which is the study of carbon-based compounds. It is a complex subject that requires a lot of memorization and understanding of various concepts, such as functional groups and reaction mechanisms. However, it is also a very rewarding subject because it helps us understand the chemistry of living organisms and the processes that occur in our bodies.Another aspect of chemistry that I find fascinating is the use of analytical techniques to identify and quantify substances. For example, spectroscopy is a powerful toolthat allows us to determine the structure of molecules and the presence of certain functional groups. Chromatographyis another technique that is commonly used to separate and analyze mixtures of compounds.Overall, chemistry is a challenging but rewardingsubject that has many practical applications in fields such as medicine, materials science, and environmental science.中文：化学是一门迷人的学科，涉及物质及其性质的研究。
化工专业英语写作范文
化工专业英语写作范文English:Chemical engineering is a highly complex and interdisciplinary field that encompasses the principles of chemistry, physics, mathematics, and engineering. The scope of study in chemical engineering includes design, development, operation, and optimization of processes and systems for the production of chemicals, fuels, materials, and pharmaceuticals. As a chemical engineering student, I have been exposed to various courses and practical experiences that have equipped me with the knowledge and skills necessary to tackle real-world challenges in the industry. Through courses such as thermodynamics, transport phenomena, and reaction engineering, I have gained a deep understanding of fundamental principles and their applications in designing and optimizing chemical processes. In addition, I have been involved in research projects and internships that have allowed me to apply theoretical concepts to practical problem-solving, further enhancing my problem-solving and critical thinking abilities. Furthermore, my involvement in extracurricular activities such as student organizations and competitions has honed my communication, teamwork, and leadership skills, all of which areessential in the chemical engineering profession. I am confident that my solid foundation in chemical engineering theory and practical experience makes me well-prepared to contribute to the industryand make a positive impact on society.中文翻译:化工是一个高度复杂且跨学科的领域，涵盖了化学、物理、数学和工程的原理。
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• 病句：He studies very hard and his leisure hours are devoted to lessons. • 他学习非常努力，空闲时间全花在功课上。 • 此句两分句主语不一致，较差，改成如下句子 就好些。 • He studies very hard, and devotes his leisure hours to lessons. • 病句：No matter how force is produced, we can measure it in pounds. • 不管力是如何产生的，都可用磅来计算。 • No matter how force is produced, it can be measured in pounds.
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1.3 不对等的思想用对等的连接词加以 连接
• 病句：Our classmate was ill and it was the reason why he was absent so long.（我们班那位同学生 病了，这是他缺课这么久的原因。） • 这句话把重要性不同的从句并列，破坏了句子 统一性，改正如下： • The reason why our classmate was absent so long was that he was ill. • 或 Our classmate was absent for such a long time because he was ill.
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• 1.2 把应该密接的思想分开来
• 病 句 ： Mr. Wang was a wonderful electrical engineer, He was also a mathematical genius. At first he worked in a telegraph office and had to leave because he became deaf. Finally he retired to Tianjin, and lived alone. • 除了给儿童或初学外文的人写作时，需要简 短的句子外，一般在写作上很少都是简单句— —主+谓+宾一类的格式，科学论文也不例外， 一联串的短句，犹如一架不停开放的机关抢， 声音单调而机械，使人看了神经紧张，因而在 文字上不能起到吸引读者的作用，上文可改写：
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• 2.2 修饰词的使用
•
分词，动名词，不定式，省略句等在使用时，
要注意用主语的呼应，不可使它孤零零地无所
依附，或依附在错误的词上，而成为无所属或
架空的修饰词，使人费解。
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• 2.2.1 分词 • 误：Differentiating both sides with respect to x, the equation becomes x2+y2=z2. equation本身不 能进行differentiating，因此differentiating成了 架空的修饰词，造成不连贯。 • 正：Differentiating both sides with respect to x, we obtain the equation x2+y2=z2. • 误：Being short of trucks, the machine parts had to be carried to the works. • 正：Being short of trucks, they had to carry the machine parts to the works.
• 1.4.3 没有理由地突然改变时态和语态
• 病句：For the tenth time he sent his manuscript to the editor, but again it is returned to him. • They would save almost $500 if they can reuse the containers.
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• Mr. Wang was not only a wonderful electrical engineer but also a mathematical genius. Owing to deafness he had to leave the telegraph office where he first worked and retired to Tianjin, and lived alone. • 王先生不仅是一位出色的电气工程师，还是一 位数学天才，由于耳聋，他不得不离开当初他 工作的电报局而退休到天津，在那里他独自生 活着。
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• 误：He moved steadily neither looking left nor right, neither to slacken nor hastening his footsteps. • 正：He moved steadily looking neither left nor right neither slackening nor hastening his footsteps. • 误：Geophysics provides a method of finding oil, several kinds of ore, and the probable means of exploiting them. • The probable means 和 oil及several kinds of ore 意思不平行，不能放在finding的宾语位置上。
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• 1.4.2 没有理由地改变主语或宾语的数
• 病句：(1) If one tries hard, they can pass the entrance examination. • (2) He carefully wiped each of the instruments and put them away.
1子里两个或两个以上的句子成分起 同一种职能时，应当使用相当的词类，使它们 对 称 。 在 使 用 并 列 连 接 词 如 and, but, or, both…and, not only…but also, either…or, neither…nor, 等，应该名词连名词，动词连动 词，从句连从句。如果连接的成分不对称，就 会破坏句子结构的对称性，就会破坏连贯性。
• 这个句子语法正确，但内容过多，含意也不密 切相连，使人抓不住要点，破坏了句子统一性， 如换成三个句子，则层次清楚。
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• The quality of the half-tone reproduction depends both on the grade of paper used and on the fineness of the screen. In general, glassy paper and finer screens give better detail, but the limit is set by the absorbency of the paper and the quality of the printing. Not every printer is equipped to reproduce half-tones with maximum clarity.
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1.4 没理由地突然改变句子结构
• 1.4.1 突然改变主语和动词的语态 • 病句：He ran to the station and the train was taken by him. • 应改为：He ran to the station and took the train. • 这里不是说一句中的并列谓语或并列复合句中 绝对不能使用不同的语态，只是说在能够一致 时，应尽量一致。
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1.1 把两个不相关连的思想放在一起
• 病 句 ： (1) The quality of the half-tone reproduction depends both on the grade of the paper used (the glossier the better) and on the fineness of the screen, in general the finer screen giving the better detail, but the limit is set by the absorbency of the paper and the quality of the printing, not every printer being equipped to reproduce half-tones with maximum charity.
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2. 连贯性(Coherence)
• 一篇好的论文犹如一条长链，每一节是一个 环，一节很自然地带来另一节，一句带来另一 句。作者的思想自始至终要相互连续，也就是 要有连贯性，句与句之间要有技巧的连接，词 与词之间，词组与词组之间的关系要明确，使 人一目了然。修饰词、连接词、先行词、转换 词序等要处理得当，否则会引起不连贯，要达 到连贯性，应注意以下几点：
第五章 科技英语中常用修辞学
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•
文章是由段落组成的，段落又是由句子组成 的，句子是表达思想感情的最小语言单位，因 此要把文章写好，就必须把句子造好，每个段 落写好，写好段落和要造好句子就必须掌握四 大要素：统一性，连贯性，强势性和简洁性。
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1．统一性(unity)
• 句子的统一性包括每一个句话都有一个明确 的中心思想，一句话只允许讲述一个中心思想， 一句中若出现两个或两个以上相关连的思想时， 我们要判断哪个是主要思想，哪个是从属思想？ 分别以主句和从句将思想表达出来。如果两个 思想重要性相等，又密切关连，则用并列连接 词，写出并列句，如果两个或更多的思想互不 关连，则用两个或更多的句子来表达，否则将 两个以上互不关联的概念放入一个句子，时而 以甲为对象，时而以乙作对象，变得语无论次， 就破坏了句子的统一性。