Unit 2 Machine ElementsI. Lead inInformation related to the textDo you know what is referred to as a machine element? Which elements are associated in pairs? Can you give an example? What is the most common machine element? How can the supporting structure be assembled? 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 Study1. 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 Business 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 pressure test is over. Now decrease the pressure , 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 process.对一个过程﹝进程﹞中的数据进行操作。
3）Able to assemble and disassemble 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. associate [ə'səuʃieit] n. 同伴, 伙伴v. 联合, 联想adj. 副的1）I don't want to associate myself with them any more.我不愿再和他们交往了。
2）She associated happiness with having money.她把幸福和有钱联想到一起。
3）We should associate ourselves with the large firm.我们应该和这家大公司联合。
4）Medias associate 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 process and evolve for another. 没有人能为别人推移和进化。
3）Your raising of consciousness through love and responsibility nourishes us, replenishes us, and expands our consciousness 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 points1. 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 predecessors' 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, progress input is control by process, 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。