【专业英语】4-Comparison of Chain and Step Polymerizations

Comparison of Chain and Step Polymerizations

Chain polymerization proceeds by a distinctly different mechanism from step polymerization. The

most significant difference is that high-molecular-weight polymer is formed immediately in a chain

polymerization. A radical, anionic, or cationic reactive center, once produced, adds many monomer

units in a chain reaction and grows rapidly to a large size. The monomer concentration decreases

throughout the course of the reaction as the number of high-polymer molecules increases. At any

instant the reaction mixture contains only monomer, high polymer, and the growing chains. The 4 molecular weight of the polymer is relatively unchanged during the polymerization, although the

overall percent conversion of monomer to polymer increases with reaction time.

The situation is quite different for a step polymerization. Whereas only monomer and the

propagating species can react with each other in chain polymerization, any two molecular species

present can react in step polymerization. Monomer disappears much faster in step polymerization as

one proceeds to dimer, trimer, tetramer, and so on. The molecular weight increases throughout the

course of the reaction, and high-molecular-weight polymer is not obtained until the end of the

polymerization. Long reaction times are necessary for both high percent conversion and high

molecular weights.

Whether a particular monomer can be converted to polymer depends on both thermodynamic and

kinetic considerations. The polymerization will be impossible under any and all reaction conditions if

it does not pass the test of thermodynamic feasibility. Polymerization is possible only if the free-

energy difference ΔG between monomer and polymer is negative.

A negative ΔG does not, however, mean that polymerization will be observed under a particular set

of reaction conditions (type of initiation, temperature, etc.). The ability to carry out a

thermodynamically feasible polymerization depends on its kinetic feasibility—on whether the process

proceeds at a reasonable rate under a proposed set of reaction conditions. Thus, whereas the

polymerization of a wide variety of unsaturated monomers is thermodynamically feasible, very

specific reaction conditions are often required to achieve kinetic feasibility in order to accomplish a

particular polymerization.

The carbon–carbon double bond in vinyl monomers and the carbon–oxygen double bond in

aldehydes and ketones are the two main types of linkages that undergo chain polymerization. The

polymerization of the carbon–carbon double bond is by far the most important of the two types of

monomers. The carbonyl group is not prone to polymerization by radical initiators because of its

polarized nature:

Aldehydes and ketones are polymerized by both anionic and cationic initiators.

Effects of Substituents

Unlike the carbonyl linkage, the carbon–carbon double bond undergoes polymerization by both

radical and ionic initiators. The difference arises because the p-bond of a vinyl monomer can respond

appropriately to the initiator species by either homolytic or heterolytic bond breakage:

A wide range of carbon–carbon double bonds undergo chain polymerization. Table 3-1 shows monomers with alkyl, alkenyl, aryl, halogen, alkoxy, ester, amide, nitrile, and heterocyclic substituents on the alkene double bond.

4

Whether a vinyl monomer polymerizes by radical, anionic, or cationic initiators depends on the inductive and resonance characteristics of the substituent(s) present. The effect of the substituent manifests itself by its alteration of the electron-cloud density on the double bond and its ability to stabilize the possible radical, anion, or cation formed. Electrondonating substituents such as alkoxy, alkyl, alkenyl, and phenyl increase the electron density on the carbon–carbon double bond and facilitate its bonding to a cationic species. Further, these substituents stabilize the cationic propagating species by resonance. Electron-withdrawing substituents such as cyano and carbonyl (aldehyde, ketone, acid, or ester) facilitate the attack of an anionic species by decreasing the electron density on the double bond.

Contrary to the high selectivity shown in cationic and anionic polymerization, radical initiators bring about the polymerization of almost any carbon–carbon double bond. Radical species are neutral and do not have stringent requirements for attacking the p-bond or for the stabilization of the propagating radical species. Resonance stabilization of the propagating radical occurs with almost all substituents. Thus, almost all substituents are able to stabilize the propagating radical by delocalization of the radical over two or more atoms.

Almost all monomers containing the carbon–carbon double bond undergo radical polymerization, while ionic polymerizations are highly selective (Table 3-1). Cationic polymerization is essentially limited to those monomers with electron-releasing substituents such as alkoxy, phenyl, vinyl, and 1,1-dialkyl. Anionic polymerization takes place with monomers possessing electron-withdrawing groups such as nitrile, carbonyl, phenyl, and vinyl. The selectivity of ionic polymerization is due to the very strict requirements for stabilization of anionic and cationic propagating species.

Ionic polymerizations, especially cationic polymerizations, are not as well understood as radical

polymerizations because of experimental difficulties involved in their study. The nature of the reaction media in ionic polymerizations is often not clear since heterogeneous inorganic initiators are often involved. Further, it is extremely difficult in most instances to obtain reproducible kinetic data because ionic polymerizations proceed at very rapid rates and are extremely sensitive to the presence of small concentrations of impurities and other adventitious materials. The rates of ionic polymerizations are usually greater than those of radical polymerizations.

Ionic polymerizations are usually carried out in solvents of low or moderate polarity such as 4 tetrahydrofuran, ethylene dichloride, and pentane, although moderately high polarity solvents such as nitrobenzene are also used. In such solvents one usually does not have only a single type of propagating species. For any propagating species such as ~BA in cationic polymerization, one can visualize the range of behaviors from one extreme of a completely covalent species (I) to the other of a completely free (and highly solvated) ion (IV )

The intermediate species include the tight or contact ion pair (II) (also referred to as the intimate ion pair) and the solvent-separated or loose ion pair (III). The intimate ion pair has a counter- or gegenion of opposite charge close to the propagating center (unseparated by solvent). the solvent-separated ion pair involves ions that are partially separated by solvent molecules. The propagating cationic chain end has a negative counterion. For an anionic polymerization the charges in species II-IV are reversed; that is, B carries the negative charge and A the positive charge. There is a propagating anionic chain end with a positive counterion. Alternate terms used for free ion and ion pair are unpaired ion and paired ion, respectively.

Most ionic polymerizations involve two types of propagating species, an ion pair and a free ion IV, coexisting in equilibrium with each other. The identity of the ion pair (i.e., whether the ion pair is best described as species II or III) depends on the particular reaction conditions, especially the solvent employed. Increased solvent polarity favors the loose ion pair while the tight ion pair predominates in solvents of low polarity. The ion pairs in cationic polymerization tend to be loose ion pairs even in solvent of low or moderate polarity since the counterions (e.g., bisulfate, SbClˉ6 , perchlorate) are typically large ions. The lower charge density of a large counterion results in smaller electrostatic attractive forces between the propagating center and counterion. The nature of the ion pairs is much more solvent-dependent in anionic polymerizations where the typical counterion (e.g., Li+, Na+) is small. The covalent species I is generally ignored since it is usually unreactive (or much lower in reactivity) compared to the other species. Free ion concentrations are generally much smaller than ionpair concentrations but the relative concentrations are greatly affected by the reaction conditions. Increased solvent polarity results in a shift from ion pairs to free ions. The nature of the solvent has a large effect in ionic polymerization since the different types of propagating species have different reactivities. Loose ion pairs are more reactive than tight ion pairs. Free ions are orders of magnitude higher in reactivity than ion pairs in anionic polymerization. Ion pairs are generally no more than an order of magnitude lower in reactivity compared to free ions in cationic polymerization.

Various initiators can be used to bring about the polymerization of monomers with electronreleasing. Substituents Protonic (Br?nsted) acids initiate cationic polymerization by protonation of the olefin. The method depends on the use of an acid that is strong enough to produce a resonable concentration of the protonated species

but the anion of the acid should not be highly nucleophilic; otherwise it will terminate the 4 protonated olefin by combination (i.e., by covalent bond formation).

The nomenclature for positively charged organic ions has undergone some change. The older term, no longer used, for the trivalent, trigonal sp2-hybridized species such as those in Eqs. 5-1 and 5-2 is carbonium ion. Olah [1972, 1988] proposed that carbenium ion be used instead with the term carbonium ion being reserved for pentavalent charged carbon ions (e.g., nonclassical ions) and the term carbocation encompassing both carbenium and carbonium ions. The term carbenium ion for the trivalent carnbon ion has not taken firm hold. Most text and journal references use the term carbocation, and so will this text. The term carbocation polymerization is used synonymously with cationic polymerization in the literature.

The requirement for the anion not to be excessively nucleophilic generally limits the utility of most strong acids as cationic initiators. Hydrogen halides are ineffective as initiators of cationic polymerization because of the highly nucleophilic character of halide ions.

Various Lewis acids are used to initiate cationic polymerization, generally at low temperatures, with the formation of high-molecular-weight polymers in high yield. These include metal halides (e.g., AlCl3, BF3, SnCl4, SbCl5, ZnCl2, TiCl4) and their organometallic derivatives (e.g., RAlCl2, R2AlCl, R3Cl). Lewis acids are the most important means of initiating cationic polymerization. Aluminium, boron, tin, and titanium halides are the most frequently used Lewis acids.

Initiation by Lewis acids almost always requires and/or proceeds much faster in the presence of either a proton donor (protogen) such as water, hydrogen halide, alcohol, and carboxylic acid, or a carbocation donor (cationogen) such as an alkyl halide (e.g., t-butyl chloride and triphenylmethyl chloride), ester, ether, or anhydride. Thus, dry isobutylene is unaffected by dry boron trifluoride but polymerization occurs immediately when trace amounts of water are added. The terminology of Kennedy and Marechal is used in here; the protogen or cationogen is referred to as the initiator, while the Lewis acid is the coinitiator. The reader is cautioned that much of the published literature until 1990 or so used the reverse terminology. The protogen or cationogen is referred to as the initiator since it supplies the proton or cation that ultimately adds to monomer to initiate polymerization. The initiator and coinitiator, representing an initiating system, react to form an initiator–coinitiator complex (or syncatalyst system), which then proceeds to donate a proton or carbocation to monomer and, thus, to initiate propagation.

（Principles of Polymerization（Fourth Edition）, edited by George Odian，John Wiley & Sons, Inc. 2004）

汽车专业英语翻译综合

第一章汽车总论 1)Today’s average car contains more than 15,000 separate, individual parts that must work together. These parts can be grouped into four major categories: body, engine, chassis and electrical equipment 。P1 现在的车辆一般都由15000多个分散、独立且相互配合的零部件组成。这些零部件主要分为四类：车身、发动机、底盘和电气设备。 2)The engine acts as the power unit. The internal combustion engine is most common: this obtains its power by burning a liquid fuel inside the engine cylinder. There are two types of engine: gasoline (also called a spark-ignition engine) and diesel (also called a compression-ignition engine). Both engines are called heat engines; the burning fuel generates heat which causes the gas inside the cylinder to increase its pressure and supply power to rotate a shaft connected to the power train. P3 发动机作为动力设备，常见的类型是内燃机，其原理是通过发动机缸内的液体燃料燃烧而产生能量。发动机可分为两类：汽油机（点燃式）和柴油机（压燃式），都属于热力发动机。燃料燃烧产生热量使缸内气压上升，产生的能量驱动轴旋转，并传递给动力传动系。 第二章内燃机 1)Power train system: conveys the drive to the wheels 2)Steering system: controls the direction of movement 3)Suspension system: absorbs the road shocks 4)Braking system: slows down the vehicle P4 传动系把发动机输出的扭矩传递给驱动轮。传动系包括离合器（对应机械变速器）或液力变矩器（对应液力自动变速器）、变速器、驱动轴、主减速器、差速器和驱动桥。 5)Drum brakes have a drum attached to the wheel hub, and braking occurs by means of brake shoes expanding against the inside of the drum. With disc brakes, a disc attached to the wheel hub is clenched between two brake pads. P6 鼓式制动器的制动鼓和轮毂连接，制动蹄张开压紧制动鼓内侧从而产生制动。在盘式制动器上，连着轮毂的制动盘被紧紧夹在两个制动块之间。 1)Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn.The power stroke"uses up"the gas,so means must be provided to expel the burnt gas and recharge the cylinder with a fresh petrol-air mixture:this control of gas movement is the duty of the valves;An inlet valve allows the mixture to enter at the right time and an exhaust valve lets out the burnt gas after the gas has done its job . P10 活塞通过连杆和曲轴连接，使得气体带动曲轴旋转半圈。作功冲程耗尽了所有的气体，这样就必须采取相应的措施排出废气并且向气缸内充入新的可燃混合气：气体的运动由气门来控制。进气门使可燃混合气在恰当的时刻进入气缸，排气门使燃烧后的废气排出气缸。 2)The spark-ignition engine is an internal-combustion engine with externally supplied in ignition,which converts the energy cntained in the fuel to kinetic energy.The cycle of operations is spread over four piston strokes. To complete the full cycle it takes two revolutions of the crankshaft. P11 火花点火式发动机是由外部提供点火的内燃机，从而将含在燃料内的能量转化成动能。发动机的一个工作循环分布在活塞的四个行程中，一个完整的工作循环曲轴需要转动两圈。 3)The oil pump in the lubricating system draws oil from the oil pan and sends it to all working parts in the engine. The oil drains off and runs down into the pan. Thus,there is constant circulation of oil between the pan and the working parts of the engine. P15

微电子专业英语

微电子学专业词汇 A be absorb in 集中精力做某事 access control list 访问控制表 active attack 主动攻击 activeX control ActiveX控件 advanced encryption standard AES,高级加密标准 algorithm 算法 alteration of message 改变消息 application level attack 应用层攻击 argument 变量 asymmetric key cryptography 非对称密钥加密 attribute certificate属性证书 authentication 鉴别 authority 机构 availability 可用性 Abrupt junction 突变结 Accelerated testing 加速实验 Acceptor 受主 Acceptor atom 受主原子 Accumulation 积累、堆积 Accumulating contact 积累接触 Accumulation region 积累区 Accumulation layer 积累层 Active region 有源区 Active component 有源元 Active device 有源器件 Activation 激活 Activation energy 激活能 Active region 有源（放大）区 Admittance 导纳 Allowed band 允带 Alloy-junction device 合金结器件 Aluminum(Aluminium) 铝 Aluminum – oxide 铝氧化物 Aluminum passivation 铝钝化 Ambipolar 双极的 Ambient temperature 环境温度 Amorphous 无定形的，非晶体的 Amplifier 功放扩音器放大器Analogue(Analog) comparator 模拟比较器 Angstrom 埃 Anneal 退火

专业术语英语整理

The term “enzyme” was coined by Wilhelm Kuhne.创造 crystallized 结晶centrifugal supernatant 离心上清液 were used to imitate enzymes mesoporous介孔材料，多孔 DMF-2甲基甲酰胺 Polymer with enzyme-like activity 聚合物 noble-metal nanoclusters 贵金属纳米团簇 In the presence of dopamine在多巴胺的存在下 Molecularly imprinted polymers were invented by 分子印迹聚合物 Nano ceria as superoxide dismutase mimic. 纳米二氧化铈作为超氧化物歧化酶模拟。 peroxidase mimic. 过氧化物模拟酶catalase,过氧化氢酶 Nano ceria as catalase and oxidase mimic纳米二氧化铈过氧化氢酶和氧化酶模拟

metal sulfide 硫化物 cobalt porphyri n钴 manganese锰facile温和的 chemicals and reagent s化学药品和试剂syring注射器 thioacetamide 硫代乙酰胺 stretching vibration 伸缩振动峰 carbonyl group羰基 aromatic acid 芳香酸 calibration curve 校准线 have been extensively explored to mimic the structures and functions of natural enzymes through various approaches.and several monographs andnumerous excellent reviews have been published have been found to exhibit unexpected enzyme-like Although the progress and achievements of classic artificial enzymes have been thoroughly reviewed in the literature, no comprehensive review has been devoted to nanozymes we discuss the current challenges facing nanozyme technologies and future directions to realize their great potential. 新方法 Hybrid materials（杂化材料） formed by incorporating inorganicmaterials into a polymeric matrix have even more promisingadvantages, such as novel

汽车专业英语翻译

Unit1 发动机是汽车的心脏。汽车引擎的目的是将燃料转化为能量使汽车移动。最简单的方法是在发动机内部燃烧燃料。,因此,汽车发动机是一种内燃机,缸内燃烧燃料和燃烧的扩张力量转换成旋转力用来驱动汽车。 这里有多种类型的内燃机分为往复式和旋转式引擎;火花式点火或压缩式点火发动机;代用燃料发动机。 往复式发动机 最熟悉的组合是往复式,火花点火,四冲程汽油发动机,如图1-1a所示。现代汽车通常是由水冷活塞式内燃机,安装在汽车的前面,它的力量可以被传送到前轮，传到后轮,或所有车轮轮。一些汽车使用风冷式发动机,但这些通常效率不及液冷式。往复式发动机的另一个主要类型是柴油发动机(如图果1-1b所示),这是使用重型车辆，如卡车，公共汽车和少数家庭轿车。柴油和汽油发动机一般采用四冲程循环。 转子式发动机 转子式内发动机,也叫汪克尔发动机,由德国的Felix~Wankel在1954年开发的,可以提供一种低废气排放和大规模生产的可行性的发动机来替代往复式发动机机。在这种发动机中，三面转子在燃烧室的自由空间内旋转使其随着转子转动压缩和膨胀,见图1 - 2。燃料被吸入、压缩和被点火系统的点燃。膨胀的气体带动转子然后废气排出,如图1 - 3所示。旋转式引擎没有气门,活塞,连杆,往复部件,或曲轴。它提高了马力,基本上不会有震动,但它的油耗是高于传统活塞式发动机。 代用燃料汽车 内燃机消耗大量的石油,并造成严重的空气污染,因此,其他类型的燃料和非常规引擎被研究和发展。 可替代燃料汽车(AFV)是一种用常见的油箱的柔性燃料车辆，设计一种在不同混合的无铅汽油与乙醇或双燃料汽车运行，一种可使用替代燃料和传统燃料。一种高科技车辆(A TV)结合了新引擎,动力传动机构,传动系系统显著提高燃油经济性。最理想的替代燃料发动机燃烧燃料比传统汽油内燃机更为简洁,但仍然能够使用现有的加油站。 混合动力电动车 混合动力汽车或者混合电动汽车(HEV)(如图1 - 4所示),是由两个或两个以上的能源,其中之一是电力可以高英里每加仑，低排放。有两种类型的混合动力汽车,串联和并联式。在串联式电动汽车中,车辆动力所有动力来自同一个源头。例如,一个电动马达驱动的汽车电池和内燃机驱动发电机给电池充电。在并联混合动力,电力是通过这两个路径,电动机和内燃机驱动车辆。这一点,可能有助于电力汽车的电动发动机空转和加速度。内燃机巡航时,驱动传动系和给电池充电。 在当前生产混合动力车发动机和电动马达连接,同样的传播协助下电动引擎可以更小。

汽车专业英语翻译

About car engine Of all automobile components,an automobile engie is the most complicated assembly with dominant effects on the function of an autombile.So, the engine is generally called the"heat"of an automobile. 在汽车的所有部件中，汽车发动机是最复杂的组件，其对整车性能有着决定性的作用。因而发动机往往被称作发动机的“心脏”。 There are actually various types of engines such as electric motors,stream engines,andinternal combustion engines.The internal combustion engines seem to have almost complete dominance of the automotive field.The internal combustion engine,as its name indicates,burns fuel within the cylinders and converts the expanding force of the combustion into rotary force used to propel the vehicle. 事实上，按动力来源分发动机有很多种，如电动机、蒸汽机、外燃机等。然而内燃机似乎在发动机领域有着绝对的统治地位。就像其字面意思一样，内燃机的染料在气缸内燃烧，通过将燃烧产生气体的膨胀力转换成转动力来驱动发动机前进。 Engine is the power source of the automobile.Power is produced by the linear motion of a piston in a cylinder.However,this linear motion must be changed into rotary motion to turn the wheels of cars or trucks.The puston attached to the top of a connecting rod by a pin,called a piston pin or wrist pin.The bottom of the connecting rod is attached to the crankshaft.The connecting rod transmits the up-and-down motion of the piston to the crankshaft,which changes it into rotary motion.The connecting rod is mounted on the crankshaft with large bearings called rod bearing.Similar bearings, called main bearings,are used to mount the crankshaft in the block. 发动机是整部车的动力来源。能量来自于活塞在气缸内的（往复）直线运动。然而这种（往复）直线运动必须要转换成旋转运动才能驱动车轮。活塞与连杆通过一个销来连接，这个销称为活塞销。连杆的下部连接于曲拐。连杆把活塞的上下往复运动传递给曲拐，从而将往复直线运动转变成旋转运动。连杆和曲拐的连接使用大的轴承，称之为连杆轴承，类似的轴承也用于将曲轴连接到机体，称之为主轴承。 They are generally two different types of cooling system:water-cooling system and air-cooling system.Water-cooling system is more common.The cooling medium, or coolant, in them is either water or some low-freezing liquid, called antifreeze.A water-cooling system consists of the engine water jacket, thermostat, water pump, radiator, radiator cap, fan, fan drive belt and neccessary hoses. 主要有两种类型的冷却系统：水冷和风冷。水冷系统更为普遍。系统所用冷却介质或是冷却液常委水或其他低凝固点液体，称为抗凝剂。一个完整的水冷系统包括机体水套，节温器，水泵，散热器，散热器罩，风扇，风扇驱动皮带和必需的水管。 A water-cooling system means that water is used as a cooling agent to circulate through the engine to absorb the heat and carry it to the radiator for disposal.The ebgine is cooled mainly through heat transfer and heat dissipation.The heat generated by the mixture burned in the engine must be transferred from the iron or aluminum cylinder to the waterin the water jacket.The outside of the water jacket dissipates some of the heat to the air surrounding it, but most of the heat is carried by the cooling water to the radiator for dissipation.When the coolant temperature in the system reaches 90°,the termostat valve open fully, its slanted edge shutting off

电子信息专业英语复习资料

电子信息专业英语复习资料 一、基本术语（英译汉） 1.probe探针 2.real time operational system 实时操作系统 3.debugger 调试器 4.sourse code 源代码 5.software radio wireless LAN 软件无线电网络 6.base station 基站 7.top-down approach 自顶向下分析法 8.variable 变量 9.data compress 数据压缩 10.signal conditioning circuit 信号调理电路 11.Chebyshev Type Ⅰfilter 切比雪夫Ⅰ型滤波器 12.vertical resolution 垂直分辨率 13.device driver 设备驱动 https://www.wendangku.net/doc/2211173197.html,piler 编译器 15.template 模板 16.concurrent process 并发进程 17.object recognition 目标识别 18.Discrete Time Fourier Transform 离散傅立叶变换 https://www.wendangku.net/doc/2211173197.html,bined circuit 组合逻辑电路 20.impedance transform 阻抗变换器 21.voltage source 电压源22.passive component 无源器件 23.quality factor 品质因数 24.unit-impulse response 单位脉冲响应 25.noise origin 噪声源 26.Domino effect 多米诺效应 27.output load 输出负载 28.cordless phone 无绳电话 29.Antenna 天线 30.harmonic interference 谐波干涉 31.Parallel Resonant 并联谐振 32.voltage control oscillator 压控振荡器 33.adaptive delta modulation 自适应增量调制 34.amplitude modulation 调幅 二、缩略语（写出全称） 1.LSI：large scale integration 2.PMOS ：p-type metal-oxide semiconductor 3.CT：cycle threshold 4.MRI：magnetic resonance imaging 5.ROM：read-only memory 6.DRAM ：dynamic random access memory 7.TCXO ：temperature compensated X'tal (crystal) Oscillator https://www.wendangku.net/doc/2211173197.html,B：Universal Serial Bus 9.DCT：discrete cosine transform

英语-名词解释

名词 英语语法分为词法和句法，分别是研究词类和句子的。英语共有十大词类，他们分别是名词、动词、冠词、代词、数词、形容词、副词、介词、连词、感叹词。我们会在以后的课程中一一学习。对名词的考查，通常会与主谓一致、名词的修饰词（有的只可以修饰可数名词，有的只可以修饰不可数名词）等结合起来进行考查。名词的辨析、可数与不可数、同一名词的可数与不可数的不同意义，名词的一些习惯表达法都是考查的要点。本讲重点对名词几个常见考点进行剖析。 1.名词的意义：从英语语法角度讲，表示人物、时间、地点、事物或抽象概念的词我们通常都称其为名词。例如chairman Shanghai milk physics 等。 2.名词的种类：总体上我们将英语中的名词分为 两大类专有名词 普通名词

专有名词 个体名词可数名词 名词集体名词 普通名词物质名词 抽象名词不可数名词 (A)专有名词：表示人或物所特有的名字，通常是人名、地名、书 报刊名、团体组织、机关名称等。例如Tom ,Beijing University , the United Nations. 专有名词的第一个字母要大写。 (B)普通名词：表示一类人、事物、物质或是表示一个抽象概念的 名词。例如 worker ,TV pen 等,普通名词可以分为以下四类： (1)个体名词：表示单个的人或单个的事物的名词。Chair car (2) 集体名词：表示一群人或一些事物的总称的名词。Class army police 由于本身就是复数意义，通常不再通过加-s变成复数，但是在主谓一致关系中要看是否表示整体，如果强调的是组成 该集体的个体概念时谓语动词用复数，如果表示整体要用单数，具 体情况见主谓一致部分的讲解。

汽车专业英语_单词表

unit1 body 车身chassis 底盘enclosure外壳、套hood车棚、车顶sway 摇摆frame车架steering转向、操作brake 制动weld焊接rivet铆钉bolt螺钉washer垫圈vibration 振动stabilizer稳定器ride乘坐舒适性handling操作稳定性linkages转向传动机构plier钳子distributor分电器alternator交流发电机regulator调节器carburetor化油器radiator散热器、水箱defroster除冰装置sludge金属碎屑transmission变速器differential 差速器power train 传动系unitized body 承载式车身suspension system 悬架系统steering system 转向系braking system 制动系shock absorbers减震器control arms控制臂steering wheel 转向盘steering column转向管柱steering gears 转向器tie rod 横拉杆idler arm随动臂brake shoe制动蹄disc brake 盘式制动器drum brakes 鼓式制动器ignition system 点火系统exhaust system 排气系统lubrication system 润滑系oil filters 机油滤清器drive（or propeller）shaft传动轴universal joints 万向节dynamo发电机horn喇叭swived 旋转steering box转向器timing gear 正时齿轮bevel gear 锥齿轮mesh with与啮合leaf spring 钢板弹簧stub axle 转向节 unit2 longitudinal纵向的transverse横向的reciprocate往复spin旋转piston活塞ignite点火rub摩擦quart夸脱reservoir油箱mechanical机械的enclosed被附上的gallon加仑stroke冲程camshaft凸轮轴combustion燃烧disengaged脱离啮合的flywheel飞轮internal-combustion engine内燃机diesel-fuel柴油LPG=Liquefied Petroleum Gas液化石油气体CNG=Compressed natural gas压缩天然气spark ignition火花点火compression ignition压缩点火spark plug火花塞gas-turbine engine蒸汽机Stirling engine斯特灵发动机lubricating system润滑系统oil pan油底壳oil pump机油泵exhaust system排气系统emission-control system排放控制系统energy conversion能量转换air/fuel ratio空燃比connecting rod连杆TDC=Top Dead Center上止点BDC=Bottom Dead Center 下止点intake stroke进气冲程compression stroke压缩冲程power stroke作功冲程exhaust stroke排气冲程compression ratio压缩比lifter挺柱rocker摇臂retainer弹簧座seal密封件tappet 推杆lobe凸起gasket垫圈valve train配气机构cam follower气门挺柱rocker arm摇臂combustion chamber燃烧室intake valve进气阀exhaust valve排气阀valve stem气门杆valve cover气门室盖valve port阀口valve guide气门导管 unit3

电子电气类专业英语单词汇总

课一A Communications 通讯 1. equation n.相等, 平衡, 综合体, 2. communication n. 通信, 通讯, 交通communicate v.沟通, 通信, 3. triode n.三极管 4. storage n. 存储 5.transmission n. 传输, 传送, transmit v. 传输, 转送, 传达, 传导 6. amplifier n.放大器，扩音器 amplify v. 扩大，放大，增强amplification n. 扩大，放大 7. oscillator n.振荡器 8. correlate v. 是相互关联 correlation n.相互关系, 相关(性) 9. transmitter n.发射机 transmit receive transmission reception (发射) （接收） 10.subsequent adj.随后的 课一B Capacitors 电容 1.capacitor n. 电容器 2.capacitance n. 电容量（值） Resistor resistance capacitor capacitance inductor inductance 3. fixed adj. 固定的 variable adj. 可变的 4. dielectric n. 电介质，绝缘材料 adj. 绝缘的 5. relatively adv. 相对地 absolutely adv.绝对地 6. maximum adj. 最大的 n. 最大值 minimum adj. 最小的 n. 最小值 7. farad n. 法（拉） F ohm n. 欧姆Ω Henry n. 亨（利）H 8. trimmer n. 调整者, 整理者, 9. screwdriver n. 螺丝起子，改锥课二A Radio T ransmitter无线电发射机 1. radio transmitter 无线电发射机 radio n. 无线电，无线 2. telecommunication n.电信，电信学， 无线电通信 telephone n.电话，电话机 telegraph n.电报, 电报机, 电讯报 3. transmit v. 传输, 转送, 传达, 传导, 发射, 发报 transmit receive transmission reception transmitter receiv er (发射) （接收） 4. intelligence n.信息、情报、智能 information/message n.信息 5. potential adj.潜在的, 可能的, 势 的, n.潜能, 潜力, 电位 6. generate v.产生，发生 generation n.产生, 发生, 一代,7. frequency n.频 low frequency 几个Hz到几十kHz high frequency 几个MHz到几十 MHz radio frequency 几百MHz到几 个GHz 8. pulse signal 脉冲信号 9. wavelength n.波长用λ表示 10. output n.输出，产量 input n.输入 11. band n. 带，波段，频带 课二B Electromotive Force 电动势 1. electromotive adj.电动的，电动 势的 electromotive force 电动势 2.driving adj.驱动的 driving force n. 驱动力 driving unit 传动装置 3. volt n. 伏特 4. distinguish v.区分 5. potential difference 电位差 课三A Time Constant 时常数 1.nuclear adj.原子能的， n.核武器, 有核国 nuclear arms 核武 nuclear energy 核能 2.constant n.常数 adj.不断, 不断的, time constant 时间常数 3. instantaneously adv.瞬间地，即刻 instant n.瞬息, 一会儿, 时刻 4. dependent adj. 依赖的，依赖于，取决于 5. capacitiv e adj.电容的，容性的 capacitor n.电容器 capacitance n.电容值 6.discharge n.放电v.放电 charge n.电荷，充电v.充电 7.universal 普遍的, 全体的, 通用的, 课三B RL Time Constant RL时序常数 1.inductor n.电感器 inductance n.电感值（量） inductive adj.感应的; 电感的 2. function n.功能, 函数,作用, 3. Decay n.衰减v. 衰减 decay constant 衰减常数 decay factor 衰减因子 4. reverse adj.反向的, 相反, 逆转的 5. peak value 峰值

环境科学专业英语名词解释

【环境】相对于某中心事物而言的周围境况。与某一中心事物有关的周围事物，就是这个事物的环境。 【生态环境】生态环境指生物体周围的其他生物和无机自然界，以及与作为主体的生物之间存在着种种客观的生存、营养关系和因果关系。 【环境科学】环境科学是研究人类与环境之间相互关系的科学，涉及自然科学、社会科学和技术科学，综合性很强。 【人类生态系统】人类生态系统，是指居民与其生存环境相互作用的网络结构，也是人类对自然环境适应、加工、改造而建造起来的人工生态系统。 【恒星】由炽热气体组成的、能自己发光的天体,维持恒星辐射的能源主要是热核反应。 因短期内很难发现它们位置的相对变化,故名恒星。 【脉冲星】脉冲星，就是一种变化的恒星。因为这种星体不断地发射短暂而极有规律的电磁脉冲信号 【新星】光度突然增加的爆发性恒星。 【行星】行星指的是围绕太阳运转、自身引力足以克服其刚体力而使天体呈圆球状、并且能够清除其轨道附近其他物体。 【卫星】围绕行星运行的天体。卫星本身不发光，大小、质量相差极大，运动特性很不一致。【星云】星云银河系内太阳系以外一切非恒星状的气体尘埃云。 【地球】地球是太阳的从里往外数第三颗行星，距太阳大约有150000000公里。地球每365.256 天绕太阳运行一圈，每23.9345小时自转一圈。它的直径为12756公里，只比金星大了一百多公里。 【高原】海拔高程在600m以上，表面较为平坦或略有起伏，四周常有崖壁与较低的地形单元分界。 【丘陵】地表起伏不大、山峦林立的低矮地形 【平原】地势宽广平坦，或略有起伏。海拔高程在200m以下的称为低平原。 【盆地】四周是高原或山地，中央低平的地区，外形似盆而得名。 【地球自转】地球绕其本身轴线的旋转运动。与太阳系的大多数行星一样，自转的方向是自西向东,从从北极上空向下看，为逆时针旋转 【太阳日】以太阳作参照，地球上的任意一点连续两次经过地心与太阳圆面中心连线的时间间隔，其长度是24小时。 【太阴日】月球作为参照，地球上任意一点连续两次经过地心与月球圆面中心连线的时间间隔，其长度是24小时50分。 【自转线速度】线速度是指地球上某点在单位时间内绕地轴所转过的线距离 【自转角速度】除南北两极外，地球各处的角速度都相同，平均角速度大约为每日360°，或每小时15°。 【赤道】地球绕轴自转，称自转轴，亦称地轴。地轴与地球表面的交点，称地球两极。过地轴中点且垂直于地轴的平面与地球表面的交线，称为赤道。 【地球公转】地球沿一定轨道围绕太阳的运动，称为公转。从地球北极高空看来，地球的公转方向也是自西向东，呈逆时针方向。 【近日点、远日点】每年大约1月3日，地球最接近太阳，此时的位置称为近日点；大致7月4日，地球最远离太阳，此时的位置称为远日点。 【春分点秋分点】赤道面与天球相交的大圆，叫天赤道，黄道面与天球相交的大圆，称为黄道。天赤道与黄道有两交点，分别为春分点和秋分点；春分点与秋分点之间的两个中点分别称为夏至点和冬至点 【黄赤交角】地球的公转轨道面．叫黄道面，是通过地心的一个平面，和地轴成66°34′

汽车专业英语翻译

INTERNAL COMBUSTION ENGINE 引擎燃烧室 1. principle of operation 原理 Engine and power : Engine is used to produce power. The chemical energy in fuel is converted to heat by the burning of the fuel at a controlled rate. This process is called combustion. If engine combustion occurs with the power chamber. ,the engine is called internal combustion engine. If combustion takes place outside the cylinder, the engine is called an external combustion engine. Engine used in automobiles are internal combustion heat engines. Heat energy released in the combustion chamber raises the temperature of the combustion gases with the chamber. The increase in gas temperature causes the pressure of the gases to increase. The pressure developed within the combustion chamber is applied to the head of a piston to produce a usable mechanical force, which is then converted into useful mechanical power. 译: 引擎和能量: 引擎为汽车提供能量，燃料的化学能通过燃烧，转化为热能，这个过程叫燃烧。假如燃烧在燃烧室，这样的发动机叫内燃机。假如燃烧在气缸外，这样的发动机叫外燃机。 用在汽车上的一般是内燃机，热能在燃烧室释放，燃烧室气体温度升高。气体温度的升高使气体的压力曾加，燃烧室内的高压气体作用在活塞头部产生可以利用的化学能，化学能转化为机械能。 Engine T erms : Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn. The power stroke “uses up” the gas , so means must be provided to expel the burnt gas and recharge the cylinder with a fresh petrol-air mixture :this control of gas movement is the duty of the valves ;an inlet valve allows the new mixture to enter at the right time and an exhaust valve lets out the burnt gas after the gas has done its job. Engine terms are : TDC(Top Dead Center):the position of the crank and piston when the piston is farther away from the crankshaft. BDC(Bottom Dead Center):the position of the crank and piston when the piston is nearest to the crankshaft. Stroke : the distance between BDC and TDC; stroke is controlled by the crankshaft. Bore : the internal diameter of the cylinder. Swept volume : the volume between TDC and BDC Engine capacity : this is the swept volume of all the cylinder e.g. a four-stroke having a capacity of two liters(2000cm) has a cylinder swept volume of 50cm. Clearance volume: the volume of the space above the piston when it is at TDC. Compression ratio = (swept vol + clearance vol)\(clearance vol) Two-stroke : a power stroke every revolution of the crank.

汽车专业英语词汇及重要名词解释

A （engine type) liquid cooled, in-line, 4cylinder, carb (发动机型号)水冷，直列，四缸，化油器式 (engine) compression ratio (发动机)压缩比(engine) displacement (发动机)排量(engine) fuel (发动机)燃料 13-mode 13工况 3rd gear 三档齿轮 3-way seat 三向座椅 4WD control device 四轮驱动控制装置 4WD indicator switch 四轮驱动指示灯开关 4WD lamp electrical connection 四轮驱动指示灯接线 4WD switch 四轮驱动开关 5th synchromesh assy. 五档同步器总成 6PK belt 6PK 多楔驱动皮带 A / C compressor assembly 空调压缩机总成 A / C control assembly 空调控制装置 A/C & heater assy. 空调加热器总成 A/C blower 空调鼓风机 A/C clutch 空调压缩机离合器 A/C compressor MTG bracket 空调压缩机安装支架 A/C control assy. 空调控制器 A/C housing assy. 空调箱总成 A/C low pressure switch 空调低压开关 A/C mode select switch 空调状态选择开关abdomen performance criterion 腹部性能指标 Abdominal Peak Force 腹部力峰值 ABS 防抱死制动系统 acceleration fuel system 加速系统acceleration running noise level 加速行驶噪声 accelerator interlocking type 加速踏板联锁式 accounting foundation 财政基础 Actual cycle work 实际循环功 Actual torso angle 实际躯干角 adapter 连接器additional features 附加装置 additional rule 附加法规 adjust screw 调整螺钉 adjuster cable 调整拉线 adjuster plug 调整盖 adjuster screw assy. 调整螺栓总成 adjuster washer 调整棘片 adjuster, diff. bearing 差速器轴承调整螺母Adjustment system 调节装置Administration and Registration Division 管理科 Agreement Concerning the Adoption of Uniform Technical Prescriptions for Wheeled Vehicles, Equipment and Parts Which Can Be Fitted and/or Be Used on Wheeled Vehicles and the Conditions for Reciprocal Recognition of Approvals Granted on the Basis of These Prescriptions关于对轮式车辆、安装和/或用于轮式车辆的装备和部件采用统一条件并相互认可基于上述条件批准的协定书Agreement Regulations 协定法规 air cleaner 空气滤清器 air cleaner assy. 空气滤清器总成 air cleaner cartridge 空气滤清器滤芯 Air compressor 空压机 air condition compressor 空调压缩机 air direct 空气走向 air filter 空气滤清器 air flow 空气流向 Air flow meter 空气流量计 air jet 空气量孔 air metering hole 空气量孔 air path 气道 Air Pressure of Tire 轮胎气压 Air type 空气型 air valve 空气阀 air-cooled 风冷 Aisles 通道 Alcohol 酒精 all bearing 球轴承 alternater bracket 发动机支架 alternator 交流发电机 alterntor assembly 交流发电机总成alumininum-rim 铝合金钢圈