中英文翻譯_彭程

1、Circuitmake our life better Electrical engineering is an exciting and challenging profession for anyone who has a genuine interest in,and aptitude for,applied science and mathematics.Over the past century and a half,electrical engineers have played a dominant role in the development of systems that

2、have changed the way people live and work.Satellite communication links ,telephones ,digital computer,televisions,diagnostic and surgical medical equipment, assembly-line robots,and electrical power tools are unrepresentative components of systems that define a modern technological socierty.As an el

3、ectrical engineer,you can participate in this ongoing technological revolution by improving and refining these exsisting systems and by discovering and developing new systems to meet the needs of our ever-changing socierty. Now let's simply come to understand the content of electrical engineerin

4、g in order to make our have a better understanding to the topic of this article “Circuit make our life better”.Finally, we introduce the methods of modern circuit design.1. Electrical Engineering:An OverviewElectrical engineering is the profession concerned with systems that produce,transmit,and mea

5、sure electric sigals.Electrical engineering combines the physicists model of natural phenomena with the mathematicians tools for manipulating those models to produce systems that meet practical needs.Electrical systems pervade our ves lives ;they are found in homes,schools, workplaces ,and transport

6、ation vehicles everywhere.We begin by presenting a few examples from each of the five major classifications of electrical systems: communication systems computer systems control systems signal processing systemsThen we describe how electrical engineers analyze and design such systems.Communion syste

7、ms are electrical systems that generate,transmit ,and distribute information.Well-known examples include television equipment ,such as cameras,transmitters, receivers, and VCRs; radio telescopes, used to explore theuniverse;satellite systems ,which return images of other Planets and our own;rada ssy

8、stems,used to coordinate plane flight;and telephone systems.Figure 1 A telephone systemsFigure 1depicts the major components of a modern telephone system.Starting at the left of the figure,inside a telephone,a microphone turns sound waves into electrical sigals.These sigals are carried to a switchin

9、g center where they are combined with the sigals from tens,hundreds or thousands of other telephones.The combined signals leave the switching center;their form depends on the distance they must trave. In our example, they are sent through wires in underground coaxial cables to a microwave transmissi

10、on station.Here,the signals are transformed into microwave frequencies and broadcast from a transmission antenna through air and space, via a communication satellite,to a reciving antenna.The microwave receiving station translates the microwave signals into a form suitable for further transmission,p

11、erhaps as pulses of light to be sent through fiber-optic cables. On arriving at the second switching center,the combined signals are separated,and each is routed to the appropriate telephone,where an earphone acts as a speaker to convert their received electric signals back into sound wave.Imagine t

12、he challenge involved indesigning,building,and operating each circuit in a way that guarantee that all of the hundreds of thousands of simultaneous calls have high-quality connections.Computer systems use electric signals to process information ranging from word processing to mathematician computati

13、ons.Systems range in size and power from pocket calculators to personal computers to supercomputers that perform such complex tasks as processing weather data and modeling chemical interactions of complex organic molecules. These systems include network of microcircuits, or integrated circuits-posta

14、ge-stampsized assemblies of hundreds,thousands,or millions of elecrical components that ofen operate at speeds and power levels close to fundamental physical limits,including the speed of light and the thermodynamic law.Control systems use electric signals to regulate processes. Examples include the

15、 control of temperatures,pressures, and flow rates in an oil refinery; the fuel-air mixture in a fuel-injected automobile engine;mechanisms such as the motors,doors, and lights in elevators;and the locks in the Panama Canal.The autopilot and autolanding systems that help to fly and land airplanes ar

16、e also familiar control systems.Power systems generate and distribute electric power.Electric power, which is the foundation of our technology-based society,usually is generated in large quantities by nuclear,hydroelectric,and thermal(coal-,oil-,or ags-fired)generators. Power is distributed by a gri

17、d of conductors that crisscross the country.A major challenge in designing and operating such a system is to provide sufficient redundancy and control so that failure or any piece of equipment does not leave a city,state,or region completely without power.Signal-processing systems act on electric si

18、gnals that represent information. They transform the signals and information contained in them into a more suitable form.There are many different ways to process the signals their information.For example,imagine-processing systems gather massive quantities of data from orbiting weather satellites, r

19、educe the amount of data to a manageable levels, transform the remaining data into a video imagine for the evening news broadcast.A computerized tomography(CT)scan is another example of an imagine-processing system. It takes signals generated by a special X-ray machine and transform them into an ima

20、ge suchas the one in Fig. 2.Although the original X-ray signals are of little use to a physician,once they are processed into a recognizable image the information they contain can be used in the diagnosis of diseas and injury.Figure 2 CT A scan of an adult headConsiderable interaction takes place am

21、ong the engineering disciplines involved in designing and operating these five classes of systems.Thus communication engineers use digital computers to control the flow of information.Computers contain control systems and control systems contain computers. Power systems require extensive communicati

22、ons systems to coordinate safely and reliably the operation of components,which may be spread across a continent.A signal-processing system may involve a communication link,a computer,and a control system.Although elecrical engineers may be interested primarily in one area, they must also be knowled

23、geable in other areas that interact with this area of interest.This interaction is part of what makes elecrical engineering a challenging and exciting profession.The emphasis in engineering is on making things work,so an engineer is free to acquire and use any technique,from any field,that helps to

24、get the job done.2. the methods of modern circuit designIn a field as diverse as elecrical engineering,you might well ask whether all of its branches have anything in common.The answer is yes-electric circuits.An electric circuit is a mathematical model that approximates the behavior of an actual el

25、ectric system.As such,it provide an important foundation for learning the details of how todesign and operate systems such as those just described.The models, the mathematical techniques,and the language of circuit theory will form the intellectual framework for your future engineering endeavors.As

26、a practicing engineer,you will not be asked to solve problems that have already been solved.Wheter you are trying to improve the perfomance of an existing system or creating a new system,you will be working on unsolved problems. Some general problem-solving procedures are presented here.Many of them

27、 pertain to thiking about and organizing your solutions strategy before proceeding with calculations. Identify whats given and whats to be found.In problem solving,youneed to know your destination before you can select a route for getting there. What is the problem asking you to solve or find?Someti

28、mes the goal of the problem is obvious;other times you may need to paraphrase or make lists or tables of known and unknown information to see your objective. Sketch a circuit diagram or other visual models. Translating a verbalproblem description into a visual model is often a useful step in the sol

29、ution processed. If a circuit diagram is already provided,you may need to add information into it,such as lables,values,or reference directions. You may also want to redraw the circuit in a simpler,but equivalent,form. Think of several solution methods and decide on a way of choosingamong them .Ther

30、e are many analytical tools in practic, several of which may work on a problem. But one method may produce fewer equations to be solved than another,or it may require only algebra instead of calculus to reach a solution. Such efficiencies,if you can anticipate them,can stre- amline your calculations

31、 considerably.Having an alternative methond in mind also gives you a path to pursue if your first solution attempt bogs down. Use your creativity.If you suspect that your anwser is off base or if thecalculations see to go on and on without moving toward a solution,you should pause and consider alter

32、natives.You may need to revisit your assumptions or select a different solution method.Or, you may need to takea less-conventional proproblem-solving approch, such as working backward a solution. Test your solution. Ask yourself whether the solution youve obtainedmakes sense.Does the magnitude of th

33、e answers seem reasonable?Is the solution physically realizable?You want to go further and rework the problem via an alternative method. Doing so will not only test the validity of your original answer,but will also help develop your intuition about the most efficient solution methods for various ki

34、nds of problems. In the real world,safety critical designs are always checked by several independent means.Getting into the habit of checking your answers will benefit you as a student and as a practicing engineer.Thus, this article focuses on the circuit applicatons in real life to draw readers att

35、enton on the circuit. And later we introduce the general method of circuit design,attempting to help those who have interest in circuit designing. Of course if you want to really enjoy the joy of circuit designing you must act.電 路使我們的生活更加方便舒適 對(duì)于喜愛(ài)應(yīng)用科學(xué)和數(shù)學(xué)方面并有這方面才華的人來(lái)說(shuō)，電氣工程是一個(gè)令人著迷并且具有挑戰(zhàn)性的領(lǐng)域。在過(guò)去的一個(gè)半世紀(jì)里

36、，電氣工程師已經(jīng)在推動(dòng)系統(tǒng)的發(fā)展進(jìn)步和改變?nèi)藗兊纳罟ぷ鞣绞缴习缪萘酥匾滞怀龅慕巧?。衛(wèi)星通信系統(tǒng)、電話、數(shù)字計(jì)算機(jī)、電視、醫(yī)學(xué)診斷設(shè)備和外科外科醫(yī)學(xué)設(shè)備、流水線的機(jī)器人以及電力電子工具已經(jīng)成為現(xiàn)代技術(shù)社會(huì)具有代表性的組成部分。作為一名電氣工程師，你可以通過(guò)升級(jí)或精煉目前存在的系統(tǒng)，也可以通過(guò)研究和開(kāi)發(fā)能夠適應(yīng)不斷變化的社會(huì)需求的新系統(tǒng)，從而使自己也參與到這場(chǎng)正在火熱進(jìn)行的技術(shù)革命中。現(xiàn)在就讓我們先簡(jiǎn)單了解一下電氣工程的內(nèi)容，使大家對(duì)本文的題目“電路使我們的生活更加方便舒適”，有一個(gè)更好的理解。最后我們介紹一下現(xiàn)代電路設(shè)計(jì)的方法。1. 電氣工程概述電氣工程是與生產(chǎn)、傳送、測(cè)量電信號(hào)的系統(tǒng)密切

37、相關(guān)的一門(mén)專(zhuān)業(yè)。電氣工程就是將物理學(xué)家的自然現(xiàn)象模型和數(shù)學(xué)家的數(shù)學(xué)工具結(jié)合在一起，從而創(chuàng)造一種新的模型，使這種模型能夠適應(yīng)人們的實(shí)際需求。電氣系統(tǒng)在我們的生活中隨處可見(jiàn)，在家庭、學(xué)校、車(chē)間中以及汽車(chē)中都可以看到它們的身影。電氣系統(tǒng)主要有五個(gè)分支： 通信系統(tǒng) 計(jì)算機(jī)系統(tǒng) 控制系統(tǒng) 電力系統(tǒng) 信號(hào)處理系統(tǒng)下面我們就從這五個(gè)方面中各舉一個(gè)例子，從而說(shuō)明電氣工程師是如何分析和設(shè)計(jì)和這些系統(tǒng)，也讓讀者對(duì)電氣系統(tǒng)的廣泛應(yīng)用有一個(gè)感性認(rèn)識(shí)。通信系統(tǒng)是產(chǎn)生、發(fā)射和分配信息的電子系統(tǒng)。舉幾個(gè)眾所周知的例子：電視機(jī)、照相機(jī)、發(fā)射接收機(jī)和VCR、用來(lái)探測(cè)宇宙的射電望遠(yuǎn)鏡、用來(lái)返回其它星球和我們地球圖片的衛(wèi)星通信系統(tǒng)

38、、用來(lái)確定飛機(jī)飛行坐標(biāo)的雷達(dá)系統(tǒng)以及電話系統(tǒng)。圖1 電話系統(tǒng)圖1描述了現(xiàn)代電話系統(tǒng)的幾個(gè)重要組成部分。從圖片的開(kāi)始向大家介紹這一系統(tǒng)，在一個(gè)電話系統(tǒng)里，話筒用來(lái)將聲波信號(hào)轉(zhuǎn)化為電信號(hào)。這些信號(hào)被傳送到信號(hào)交換中心，在這里它們將和來(lái)自其它成千上萬(wàn)的電話電話信號(hào)組合在一起。組合的信號(hào)從交換中心發(fā)射出去；它們的信號(hào)形式由傳播的距離決定。在我們的例子中，這些信號(hào)將通過(guò)埋藏在底下的同軸電纜傳送到一個(gè)微波站。在這里，這些信號(hào)被轉(zhuǎn)換為微波頻率的信號(hào)，然后用發(fā)射天線發(fā)射到空間，再通過(guò)通信衛(wèi)星發(fā)送到接收天線。微波接收站將微波信號(hào)轉(zhuǎn)換成某種適于遠(yuǎn)距離傳輸?shù)男盘?hào)，比如說(shuō)轉(zhuǎn)化為光脈沖信號(hào)通過(guò)光纜傳輸出去。當(dāng)?shù)竭_(dá)第二個(gè)

39、交換中心后，組合的信號(hào)被分離開(kāi)來(lái)，并且每個(gè)信號(hào)都發(fā)送給相應(yīng)的電話，在電話這邊此時(shí)的話筒當(dāng)做揚(yáng)聲器，將收到的電信號(hào)還原回聲波信號(hào)。在這個(gè)過(guò)程的每個(gè)階段，電路都對(duì)信號(hào)進(jìn)行了處理，起了重要作用?？梢韵胂笠幌拢嬲奶魬?zhàn)在于設(shè)計(jì)、制造以及運(yùn)行每個(gè)電路，每個(gè)電路都應(yīng)該能夠同時(shí)響應(yīng)成千上萬(wàn)的電話呼叫并且還要保障高質(zhì)量的連接。計(jì)算機(jī)系統(tǒng)是用電信號(hào)去處理信息，包括文字信息處理以及數(shù)學(xué)計(jì)算。計(jì)算機(jī)系統(tǒng)的大小不同，其功率強(qiáng)弱也不同。從袖珍計(jì)算器到個(gè)人電腦再到可以執(zhí)行復(fù)雜任務(wù)的超級(jí)計(jì)算機(jī)（用來(lái)處理天氣數(shù)據(jù)或建立復(fù)雜的有機(jī)分子化學(xué)反應(yīng)模型）。計(jì)算機(jī)系統(tǒng)包括了微電路網(wǎng)絡(luò)或者說(shuō)是集成電路郵票大小的集成電路包含了成千上萬(wàn)的

40、電子器件，這些元件的運(yùn)行速度和功率都接近于它們的物理極限，比如說(shuō)光速和熱力學(xué)定律的極限值。控制系統(tǒng)用電信號(hào)控制生產(chǎn)過(guò)程，比如煉油廠的說(shuō)溫度控制、壓力控制和流速的控制；電子燃油噴射式汽車(chē)發(fā)動(dòng)機(jī)里的燃油混合設(shè)備；電梯里面的機(jī)械裝置電動(dòng)機(jī)以及門(mén)和燈光控制系統(tǒng)；巴拿馬運(yùn)河的閘門(mén)控制裝置。還有可以幫助飛機(jī)自動(dòng)導(dǎo)航以及自動(dòng)著陸的控制器也是我們所熟悉的控制系統(tǒng)。電力系統(tǒng)是用來(lái)產(chǎn)生和分配電力資源的。作為現(xiàn)代工業(yè)社會(huì)基礎(chǔ)的電力資源，通常是有核電站、水電站及熱電站（用煤、油或者氣作燃料）。電能由橫跨全國(guó)的的電網(wǎng)分配。設(shè)計(jì)和運(yùn)行一個(gè)這樣的系統(tǒng)最主要的挑戰(zhàn)在于，要給整個(gè)大系統(tǒng)提供足夠的冗余和控制，以確保整個(gè)系統(tǒng)中的任意一個(gè)小部分除問(wèn)題都不會(huì)讓一個(gè)城市、或一個(gè)區(qū)域斷電。信號(hào)處理系統(tǒng)是用來(lái)處理代表信息的電信號(hào)。信號(hào)處理系統(tǒng)能夠使電信號(hào)里包含的信息以更適合分析的形式存在。有許多種不同的信號(hào)處理方法。例如，圖像處理系統(tǒng)收集到大量來(lái)自軌道氣象衛(wèi)星的數(shù)據(jù)，將這些數(shù)據(jù)壓縮到可以接受到數(shù)量并且將其處理成適于晚間新聞的視頻圖像。計(jì)算機(jī)處理的X射線斷層掃描（CT）又是另外