机电专业英语第2版电子教案Unit 2_unit2电子教案
机电专业英语第2版电子教案Unit 2由刀豆文库小编整理，希望给你工作、学习、生活带来方便，猜你可能喜欢“unit2电子教案”。
Unit 2 Machine Elements I.Lead in Information related to the text Do you know what is referred to as a machine element? Which elements are aociated in pairs? Can you give an example? What is the most common machine element? How can the supporting structure be aembled? Why does the individual reliability of machine elements become the basis for estimating the overall life expectancy of a machine? Maybe you have seen and you are much interested in some machine elements, of course also interested in these questions.In this unit, you’ll learn some machine elements and know how they are widely used in industry.Now, let’s study new words and phrases together.II.Word Study 1.individual [,indi'vidjuəl] adj.个别的n.个人,个体 1）These styles can be adapted to suit individual tastes.这些式样均可改动以适应个人不同的爱好.2）Who was the individual champion? 谁是个人项目的冠军？
3）Am I a Busine or Individual account? 我采用企业帐户还是个人帐户？ 2.dismantle [dis'mæntl] v.拆除．．．的设备, 分解
1）To dismantle or raze;tear down.拆除，毁坏：拆除，摧毁；拆毁 2）Before mounting, You can not dismantle the plug of port in case the dirty entering.装机前不得将各油口堵塞拆掉，以防脏物进入。
3）The preure test is over.Now decrease the preure , dismantle the pipe and check the inside of the pipe.压力试验通过了，把压力放掉，拆开管子，检查管子内部。3.perform [pə'fɔ:m] v.执行,表演,做
1）Lasers can be used to perform operations nowadays.现在激光可以用来做手术。
2）To perform operations on data in a proce.对一个过程﹝进程﹞中的数据进行操作。
3）Able to aemble and disaemble molds and perform mold repair work as instructed.能够组装和拆卸注塑模具，并按规定进行模具维修工作。
4.aociate [ə'səuʃieit] n.同伴, 伙伴
v.联合, 联想
adj.副的 1）I don't want to aociate myself with them any more.我不愿再和他们交往了。
2）She aociated happine with having money.她把幸福和有钱联想到一起。
3）We should aociate ourselves with the large firm.我们应该和这家大公司联合。
4）Medias aociate tightly with the society, closes to personal life, people can touch the pulse of the community.传播媒介于社会联系密切，与人民生活息息相关，人们可感觉到社会的脉搏。
5.evolve [i'vɔlv] v.进展，进化，展开
1）The American constitution was planned;the British constitution evolved.美国宪法是精心制定的, 英国宪法是约定俗成的.2）No one can proce and evolve for another.没有人能为别人推移和进化。
3）Your raising of consciousne through love and responsibility nourishes us, replenishes us, and expands our consciousne so that we may evolve further.通过爱和责任滋养我们、补充我们，我们意识提升，并且扩展我们的意识以便我们能进一步进化。
6.expectancy [ik'spektənsi] n.期待(公算)1）A quiver of expectancy ran through the audience.全场引颈以待, 群情鼎沸.2）Women have a higher life expectancy than men.女人比男人的预期寿命长.3）Greatly increased life expectancy and control board system reliability.大大提高控制线路板寿命和系统可靠性。
III．Language points
1.However simple, any machine is a combination of individual components generally referred to as machine elements or parts.译文：无论怎样简单的机床,都是由通称为机械零件或部件的单一元件组成的.说明：“be referred to as” means “be known as” or “be regarded as”(称为、叫作)，e.g.1)PMO can also be referred to as a “program management office, ” “project office, ” or “program office.项目管理办公室也可以叫作“计划管理办公室”或“计划办公室”。
2)Including credit cards, debit cards, online payment gateway and all other non-cash, to pay the bills, should be referred to as electronic payments.包括信用卡、借记卡、线上网关支付等一切非现金、票据支付的方式，都应该称为电子支付。
2.If a machine is completely dismantled, a collection of simple parts remains such as nuts, bolts, springs, gears, cams and shafts—the building block of all machinery.译文：如果把机床完全拆开, 就可以得到像螺母,螺栓,弹簧,齿轮,凸轮及轴等简单零件—所有机器的组合元件.说明：“dismantle” means “take sth.to pieces”(拆开, 拆除)
“a collection of ” means “a group of ” e.g.1)Installation & Dismantle： 展台搭建和撤展，常简称为“I &D”。2)The new government dismantled their predeceors' legislation.新政府废除了前任政府的立法。
3)Trouble is, after the inspection, people take down the fences or dismantle the alarms.问题是，在通过检查后，人们会拆掉护网或警报器。
3.A machine element is, therefore, a single unit designed to perform a specific function and capable of combining with other elements.译文：因此，机械零件就是用来设计可以执行某一特定功能，且能与其它零件配合的单一元件。
分析：“designed to perform a specific function and capable of combining with other elements” is a past participle phrases used as attribute to modify “a single unit”, it has the same function as an attributive clause.说明：“perform” means “carry out”（执行，完成）e.g.1)When to perform update, progre input is control by proce, not software.何时执行更新，进度输入是过程控制，不是软件控制。2)You can also perform a test.你也可以进行一个测试 3)Perform other tasks as required.完成要求的其他任务； “be capable of” means “be able to do”
A teacher must be capable of great patience.This is largely a matter of self-training.一名教师必须具有极大的耐心，在很大程度上这是个个人修养问题。4.The most common example of a machine element is a gear, which, fundamentally, is a combination of the wheel and lever to form a toothed wheel.译文： 机器零件中最常见的是齿轮,它实际上是由轮子和杆组成的带
有齿的轮子。
分析：which introduces a nonfinite attributive clause to modify gear.The infinitive phrase “to form a toothed wheel” is used as adverbial to expre result.5.Other fundamental machine elements have evolved from wheel and lever.译文：其他基本机械零件是由轮子和杆逐渐发展而来的.说明： “evolve from” means “develop from”
evolve [i'vɔlv] vt.发展，进化；进化；使逐步形成；推断出 vi.发展，进展；进化；逐步形成 e.g.1)Strategic goals evolve from the miion of the organization.策略的目标从组织的任务进展。
2)Great historical achievements often evolve from simple concepts.历史上的壮举，往往是从朴素的概念演变过来的。
3)No one can proce and evolve for another.没有人能为别人推移和进化。
6.standardize ['stændədaiz] v.标准化，使合于标准
1)Should perfect administration further to hearing system, make it standardized and legal.应当进一步完善行政听证制度，使其规范化、法定化。
2)This paper aims at building different types of software fault models to manage and standardize these faults.这篇文章旨在建立不同类型的故障模型，以便于管理和标准化这些故障。
7.establish [is'tæbliʃ] v.建立，确立，创办
1)Our company was established in 1994.我们的公司成立于1994年。2)We wish to establish busine relations with you.我们希望能和你们建立业务关系。
3)Prices branch, only prices branch has the right to establish the price.物价部门，只有物价部门有权利制定价格。
IV.Translating Skills
词义的确定
英汉两种语言都有一词多类、一词多义的现象。一词多类是指一个词往往属于多个词类，具有几种不同的意义。如display一词，既可做名词“显示（器）”，又可以作形容词“展览的、陈列用的”，还可做动词“显示、表现”等意思。一词多义是说同一个词类中，往往有几个不同的词义。如power 一词，做名词时，其汉语意思为“电力、功率、次方”等。在英汉翻译过程
中，我们在弄清句子结构后就要善于选择和确定句子中关键词的意义。选择和确定词义通常从以下几个方面入手：
一、根据词类确定词义
选择某个词的词义时，首先要确定这个词在句中应属于哪一种词类，然后再进一步确定其词义。下面以display为例：
Here, you have the option of defining your own display variants.这里，你有权定义你自己的显示变式。（display为名词）Often, it is best to display materials on an information table.通常，最好是把资料放在提供各类资讯的桌子上展示。（display为动词）
The reverse side of a control panel, display panel, or the like: the side with the interconnecting wiring.（display为形容词）
控制面板、显示面板或类似的面板的反面，即带有互连接线的那一面。
二、同一词类表达不同词义
英语中同一个词，同一类词，在不同的场合，往往具有不同的含义。此时，必须根据上下文的联系及整个句子的意思加以判断和翻译。例如as 这一连词：
Wear resistance improves as cutting tool hardne increase.当切削刀具的硬度越高时，其耐磨性就越好。（as引导时间状语从句）
As heat makes things move, it is a form of energy.因为热能使物体运动，所以热是能的一种形式。（as引导原因状语从句）
三、根据单词搭配情况确定词义
英译汉时，不仅必须根据上下文的联系理解词义，还需要根据词的搭配情况来理解词义。尤其在科技文献中，由于学科及专业不同，同一个词在不同的专业中具有不同的意义。比如：
The fifth power of two is thirty-two.二的五次方是三十二。（数学）With the development of electrical engineering, power can be transmitted over long distances.随着电气工程的发展, 电力能输送得非常远。（电学）Friction can cause a lo of power in every machine.摩擦能引起每一台机器功率的损耗。（物理学）
同一个词与不同的词搭配，可以产生不同的词义。如： make contact 闭合电路
make metals熔炼金属 make good
修理补偿
make a circuit接通电路
make up
补偿，配制
make over转让，移交
四、根据名词的单复数选择词义
英语中有些名词的单数或复数表达的词义完全不同。例如： 名词
单数词义
复数词义
facility
简易，灵巧
设施，工具 charge
负荷，电荷
费用 spirit
精神
酒精 Although they lost, the team played with tremendous spirit.那队输是输了，但却表现了极其顽强的精神。Whisky, brandy, gin and rum are all spirits.威士忌、白兰地、杜松子酒和朗姆酒都是烈酒。
V.Key to Exercises of the text.I 1.A machine element is a single unit designed to perform a specific function and capable of combining with other elements.The most common machine element is a gear.2.Other fundamental machine elements have evolved from wheel and lever.3.In the automotive industry only fasteners, bearings, bushings, chains, and belts are standardized.II.1.F
2.T
3.T
4.T
5.T
6.F III.1.最常见的机械零件是齿轮，实际上是由轮子和杆组成的跌有齿的轮子。
2.齿轮的坚硬性决定了它的耐磨能力。
3.制造业的工程师们集中精力，研制标准化的零件。
4.这些零件是以大批量、高规格和降低成本的条件下生产的。Key to Exercises of the reading 1.The most important properties of cutting tools are hardne at high temperature, wear resistance, and impact strength.2.The hardne of the tool and the degree to which it remains its hardne at high temperature are important in the selection of a cutting-tool material.Because all metal cutting tools begin to lose hardne when heated to sufficiently high temperatures.3.The various materials from which most metal cutting tools are made can be claified under the following principal headings: Carbon tool steel,High-speed steel, Cast alloys, Cemented carbides, Ceramics, Diamonds.4.In order to detect the time when a cutting tool should be changed.VI.阅读材料参考译文
切削刀具
金属切削刀具必须具有许多不同的性能，才能在各种恶劣条件下切削不同的金属。为满足这些要求，制作刀具需要用许多种材料。
切削刀具的性能
切削刀具最重要的性能是在高温下能保持的硬度以及耐磨损耐冲击和韧性好。
当刀具进行切削时，刀具刃口处的压力和摩擦产生了高温。达到一定高的温度时，所有的金属切削刀具便开始软化。在刀口因高温而软化的同时，刀具刃口便开始磨耗并损坏。不同的切削刀具材料在不同的温度点开始软化。因此，刀具的硬度和它在高温下所能保持的硬度是选择切削刀具材料时的重要因素。
如果切削刀具的刃口和刀面耐磨，刀具就不易磨损。切削刀具的硬度越高，耐磨性就越好。
切削刀具还必须具有高强度才能抗振动和抗冲击。切削刀具材料的强度并不都是与硬度成正比的。有些硬的刀具材料由于太脆而缺乏强度。
切削刀具材料
大多数金屑切削刀具的制作材料可分为以下几大类：
碳素刀具钢；高速钢；铸合金；硬质合金；陶瓷；金刚石。
刀具寿命，即切削刀刃在需要重新打磨之前能加工的零件数，是生产某个零件或产品的重要成本因素。当切削刀具开始变钝时必须重新打磨。如果在这时还要继续用下去，刀具会很快地磨损。
要知道什么时候该换刀具，大部分现代机床都安装了指示器来显示切削加工所耗的功率。当刀具用钝时，加工需要消耗更多的功率，并由指示器显示出来。一旦发生这种情况就应当立即打磨刀具。
