1、1. We note a highly desirable feature of hydropower plants: the speed with which they be started up, brought up to speed, connected to the power network, and “l(fā)oaded” up. This can be done in under 5 minutes, in contrast to many hours in the case of thermal plants.我們注意到水電廠高度可取的特點(diǎn)：速度與它們開始，提出了速度，連接到電力網(wǎng)

2、絡(luò)， “加載”最多。這是可以做到在5分鐘內(nèi)，在對比度到許多小時(shí)的情況下的熱植物。2. The total cost of operation includes fuel, labor, and maintenance costs, but for simplicity the only variable costs usually considered are fuel costs.總運(yùn)營成本包括燃料，勞動(dòng)力，成本和維護(hù)成本，但為了簡單起見，通常被認(rèn)為是唯一的可變成本，燃料成本。3. Most people can formulate a mental picture of a compute

3、r, but computers do so many things and come in such a variety of shapes and sizes that it might seem difficult to distill their common characteristics into an all-purpose definition.大多數(shù)人都可以制定一個(gè)精神的圖片一臺(tái)電腦，但電腦做這么多事情，有各種形狀和大小，它可能似乎很難提煉他們的共同特點(diǎn)為一個(gè)通用的定義.4. For large AC motors and particularly for high-volt

4、age motors, 2300V and above, form-wound coils are used. These coils are constructed from rectangular wire, which is bent into shape around forms and then taped.對于大型交流電機(jī)，特別是對高壓電機(jī)， 2300V及以上的，的形式纏繞的線圈的使用。這些線圈構(gòu)造從矩形線材，彎成周圍形式的形狀，然后錄音。5. 電氣工程及其自動(dòng)化專業(yè)英語涉及發(fā)變電、輸電，基本電力電子技術(shù)、計(jì)算機(jī)與控制等內(nèi)容。Electrical Engineering and A

5、utomation Professional English substation, transmission , power electronics technology , computer and control involving hair .6. 理想避雷器的伏安特性曲線是水平的，但實(shí)際上是緩慢向上的。所用的材料如鋅氧化物，是非線性電阻。Ideal arrester voltammetry characteristic curve is horizontal, but in fact is a slow upward . The materials used , such as zi

6、nc oxide, is a non - linear resistor .7 計(jì)算機(jī)系統(tǒng)由電源、微處理器、主板、存儲(chǔ)設(shè)備（硬盤等）、鼠標(biāo)、鍵盤、顯示設(shè)備、DVD驅(qū)動(dòng)器、聲卡、發(fā)聲器，以及打印機(jī)等外圍設(shè)備組成。 Computer system by the power supply , microprocessor , motherboard , storage devices (hard disk ) , mouse, keyboard , display equipment , DVD drive , sound card , sounder , as well as printers a

7、nd other peripherals composition1. 電氣工程及其自動(dòng)化專業(yè)英語涉及發(fā)變電、輸電，基本電力電子技術(shù)、計(jì)算機(jī)與控制等內(nèi)容。Electrical Engineering and Automation Professional English substation, transmission , power electronics technology , computer and control involving hair .2. 感應(yīng)電機(jī)的基本運(yùn)行原理可用簡圖3-2所示的銅盤-磁鐵實(shí)驗(yàn)來展示，并且相對運(yùn)動(dòng)、磁場和感應(yīng)電流三個(gè)方向之間的關(guān)系遵守右手規(guī)則。The b

8、asic operating principles of the induction motor can be used the thumbs of 3-2 Tongpan - magnet test to show, and the relative movement , the relationship between the three directions of the magnetic field and induced current compliance with the right-hand rule .3. 計(jì)算機(jī)系統(tǒng)由電源、微處理器、主板、存儲(chǔ)設(shè)備（如硬盤等）、鼠標(biāo)、鍵盤、

9、顯示設(shè)備、DVD驅(qū)動(dòng)器、聲卡、發(fā)聲器，以及打印機(jī)等外圍設(shè)備組成。Computer system power supply , microprocessor , motherboard , storage devices ( such as a hard disk ) , mouse, keyboard , display equipment , DVD drive , sound card , sounder , as well as printers and other peripherals .4. Most people can formulate a mental picture of

10、 a computer, but computers do so many things and come in such a variety of shapes and sizes that it might seem difficult to distill their common characteristics into an all-purpose definition.大多數(shù)人都可以制定一個(gè)精神的圖片一臺(tái)電腦，但電腦做這么多事情，在這樣一個(gè)不同的形狀和大小，它可能似乎很難提煉他們的共同特點(diǎn)為一個(gè)通用的定義。5. The total cost of operation include

11、s fuel, labor, and maintenance costs, but for simplicity the only variable costs usually considered are fuel costs.總運(yùn)營成本包括燃料，勞動(dòng)力，成本和維護(hù)成本，但為了簡單起見，通常被認(rèn)為是唯一的可變成本，燃料成本。6. We note a highly desirable feature of hydropower plants: the speed with which they be started up, brought up to speed, connected to t

12、he power network, and “l(fā)oaded” up. This can be done in under 5 minutes, in contrast to many hours in the case of thermal plants.我們注意到水電廠高度可取的特點(diǎn)：速度與它們開始，提出了速度，連接到電力網(wǎng)絡(luò)， “加載”最多。這是可以做到在5分鐘內(nèi)，在對比度到許多小時(shí)的情況下的熱植物。1. 按照方程（1-2）對電流的定義，電流并不需要是一個(gè)恒定的值，而是可以隨時(shí)間有幾種變化方式。Definition of a current in accordance with the e

13、quation (1-2 ) , the current does not need to be a constant value , but may be several variations with time .2. 感應(yīng)電機(jī)的基本運(yùn)行原理可用簡圖3-7所示的實(shí)驗(yàn)來展示，并且相對運(yùn)動(dòng)、磁場和感應(yīng)電流三個(gè)方向之間的關(guān)系遵守右手規(guī)則。The basic operating principles of the induction motor can be used to show the schematic view of the 3-7 experiments , and relative

14、movement , and the relationship between the three directions of the magnetic field and induced current compliance with the right-hand rule .3. 計(jì)算機(jī)系統(tǒng)由電源、微處理器、主板、存儲(chǔ)設(shè)備、鼠標(biāo)、鍵盤、顯示設(shè)備、DVD驅(qū)動(dòng)器、聲卡、發(fā)聲器以及打印機(jī)等外圍設(shè)備組成。Computer system by the power supply , microprocessor , motherboard , storage devices , mouse , key

15、board , display equipment , DVD drive , sound card , sound , and printers and other peripherals .4. 與熱發(fā)電廠不同，水電廠的能量來源于下落的水流，其輸出功率與水流速度和水頭有直接關(guān)系。And thermal power plants , hydropower plant 's energy comes from the whereabouts of water , the output power and the rate of water flow and head directly

16、.IVTranslate (English to Chinese): 1In small and medium horsepower sizes, rotors are made by casting aluminum into their core. In the large sizes of AC motors, bronzes or other metal are used to replace copper in making the cage.在中小型馬力大小，轉(zhuǎn)子是由壓鑄鋁到他們的核心。在交流電機(jī)的大尺寸的，青銅或其它金屬被用于在作出籠來代替銅。2 Most people can

17、formulate a mental picture of a computer, but computers do so many things and come in such a variety of shapes and sizes that it might seem difficult to distill their common characteristics into an all-purpose definition.大多數(shù)人都可以制定一個(gè)精神的圖片一臺(tái)電腦，但電腦做這么多事情，在這樣一個(gè)不同的形狀和大小，它可能似乎很難提煉他們的共同特點(diǎn)為一個(gè)通用的定義。2. The to

18、tal cost of operation includes fuel, labor, and maintenance costs, but for simplicity the only variable costs usually considered are fuel costs.總運(yùn)營成本包括燃料，勞動(dòng)力，成本和維護(hù)成本，但為了簡單起見，通常被認(rèn)為是唯一的可變成本，燃料成本。4. We note a highly desirable feature of hydropower plants: the speed with which they be started up, brough

19、t up to speed, connected to the power network, and “l(fā)oaded” up. This can be done in under 5 minutes, in contrast to many hours in the case of thermal plants.我們注意到水電廠高度可取的特點(diǎn)：速度與它們開始，提出了速度，連接到電力網(wǎng)絡(luò)， “加載”最多。這是可以做到在5分鐘內(nèi)，在對比度到許多小時(shí)的情況下的熱植物。5 In fossil-fuel power plants, coal, oil, or natural gas is burned

20、in a furnace, the combustion products heat water, converting it to steam, and the steam drives a turbine which is mechanically coupled to an electric power generator.在化石燃料發(fā)電廠，煤炭，石油，或天然氣燃燒的爐中，燃燒產(chǎn)物的熱水，將其轉(zhuǎn)換成蒸汽，蒸汽驅(qū)動(dòng)渦輪機(jī)被機(jī)械地耦合到電力發(fā)生器。6. Automatic control systems permeate life in all advanced societies toda

21、y. Such systems act as catalysts in promoting progress and development. They are integral components of any industrial society and are necessary for the production of goods required by an increasing world population.自動(dòng)控制系統(tǒng)滲透在所有先進(jìn)的社會(huì)生活。這樣的系統(tǒng)作為催化劑，推動(dòng)行業(yè)進(jìn)步和發(fā)展。他們是任何工業(yè)社會(huì)不可或缺的組成部分，越來越龐大的世界人口所需的商品的生產(chǎn)是必要的1.C

22、urrent direction and voltage polarity play a major role in determining the sign of power. It is therefore important that we pay attention to the relationship between current i and voltage u.在確定權(quán)力的標(biāo)志，電流方向和電壓極性發(fā)揮了重要的作用。我們注意電流i和電壓u之間的關(guān)系，因此，它是重要的2. A signal is any physical variable whose magnitude or va

23、riation with time contains information. This information might involve speech and music, as in radio broadcasting, a physical quantity such as the temperature of the air in a room, or numerical data, such as the record of stock market transactions.一個(gè)信號是任何物理變量，其大小隨時(shí)間的變化包含的信息。此信息可能會(huì)涉及語音和音樂，在無線電廣播，一個(gè)物理

24、量，如在一個(gè)房間里的空氣的溫度，或數(shù)值數(shù)據(jù)，如股票市場交易紀(jì)錄。3. Power losses in the power electronic converters are comprised of the switching losses and the parasitic losses. The parasitic losses account for the losses due to the winding resistances of the inductors and transformers, the dielectric losses of capacitors, the ed

25、dy and the hysteresis(磁滯) losses.在電力電子轉(zhuǎn)換器的功率損失是由將開關(guān)損耗和的寄生損耗。寄生損失占繞組電阻值的電感器和變壓器，電容器介電損耗，渦流和磁滯損失（磁滯）造成的損失。4. The primary and secondary windings in a physical transformer are wrapped one on top of the other with the low-voltage winding innermost. Such an arrangement serves two purposes: .被包裹在一個(gè)物理變壓器的初級

26、和次級繞組，一個(gè)在另一個(gè)頂部上與最內(nèi)的低壓繞組。這種安排的目的有兩個(gè)：.5. The protection scheme includes both the protective relays and switching circuits, i.e. circuit breakers. The protective relay which functions as a brain is a very important component.保護(hù)計(jì)劃包括保護(hù)繼電器和開關(guān)電路，即斷路器。作為腦的保護(hù)繼電器，其功能是一個(gè)非常重要的組成部分。. Translate (Chinese to Englis

27、h): (20 marks, 5 marks for each item)1.為了改進(jìn)閉環(huán)系統(tǒng)的運(yùn)行狀況以便輸出量盡量接近期望值，操作員由人換成了機(jī)電子系統(tǒng)。Operator is replaced by the people so that the output is as close as possible to the expected value in order to improve the health of the closed-loop system , the mechanical and electrical subsystems .2要移動(dòng)導(dǎo)體中的電子沿特定方向運(yùn)動(dòng)，必須

28、有功的轉(zhuǎn)換。To move the electrons along the specific direction , the conductor must be meritorious conversion.3從核心角度看，計(jì)算機(jī)是一個(gè)能接受輸入、處理數(shù)據(jù)、儲(chǔ)存數(shù)據(jù)，并且產(chǎn)生輸出的設(shè)備，所有這些都是依靠一系列指令完成的。From the core point of view , the computer is a can accept input, process data , store data , and generate output devices , all of which ar

29、e relying on a series of instructions to complete .4在燃煤發(fā)電廠中，煤首先被燃燒，使鍋爐中產(chǎn)生熱蒸汽，從而推動(dòng)汽輪機(jī)帶動(dòng)發(fā)電機(jī)發(fā)電。Coal-fired power plants , coal is first combustion in the boiler to produce hot steam to drive the steam turbine driven generator .1.Fig.1-2 shows the voltage across an element (represented by a rectangular b

30、lock) connected to points a and b. The plus (+) and minus (-) signs are used to define reference direction or voltage polarity.圖2示出連接點(diǎn)a和b的一個(gè)元素（所表示的矩形塊）的兩端的電壓。的加號（ +）和減號（ - ）符號被用來定義基準(zhǔn)方向或電壓極性。2. A digital signal is one that can take on values within two discrete ranges. Such signals are used to repres

31、ent ON-OFF or YES-NO information. An ordinary household thermostat delivers a digital signal to control the furnace.數(shù)字信號是，可以采取兩個(gè)獨(dú)立的范圍內(nèi)的值。這些信號被用來代表ON- OFF “或”YES -NO信息。普通的家用恒溫器提供的數(shù)字信號來控制爐內(nèi)。The electrical switches withstand high voltages and have nonzero leakage current through the switch in the off-s

32、tate. The off-state power losses are given by Poff = usoff ir . The usoff and ir are respectively the reverse bias voltage in the off-state and the reverse current through the switch.電氣開關(guān)承受高電壓和具有非零的漏電流通過開關(guān)在關(guān)斷狀態(tài)。關(guān)斷狀態(tài)的功率損耗給定的POFF = usoff紅外的。 usoff和ir分別是在關(guān)斷狀態(tài)，通過開關(guān)的電流的反向的反向偏置電壓。4. The sizes at which the

33、 transition between cast-aluminum (熔鋁) and copper rotors takes place varies among rotor manufacturers, but virtually all rotors in motor sizes of several thousand horsepower and above are built with bar-type rotors.鑄鋁（熔鋁）和銅轉(zhuǎn)子之間的過渡發(fā)生的大小不同的轉(zhuǎn)子制造商，但幾乎所有的轉(zhuǎn)子在幾千馬力的電機(jī)尺寸和上面建有條型轉(zhuǎn)子。5. Power transformers are gi

34、ven a variety of different names, depending on their use in power systems. A transformer connected to the output of a generator and used to step its voltage up to the transmissin levels is sometimes called a unit transformer.One of the transformer windings is connected to a source of AC electric pow

35、er, and the second (and perhaps third) transformer winding supplies electric power to loads. The transformer winding connected to the power source is called the primary winding or input winding, and the winding connected to the loads is called the secondary winding or output winding. If there is a t

36、hird winding on the transformer, it is called the tertiary winding.電力變壓器中給出的各種不同的名字，這取決于它們的使用在電力系統(tǒng)中。一種變壓器，連接到一臺(tái)發(fā)電機(jī)的輸出，并用于到步驟其電壓的transmissin水平有時(shí)也被稱為一個(gè)單元變壓器。之一的變壓器繞組的是，連接到交流電力的來源，和第二個(gè)（和或許第三）變壓器繞組供給電力負(fù)載。連接到電源的變壓器繞組被稱為初級繞組或輸入1由于作用在軸上的機(jī)械負(fù)荷的變化，導(dǎo)致機(jī)器運(yùn)轉(zhuǎn)速度偏離了期望值。As the role of changes in mechanical load on th

37、e shaft , the machine speed deviation from expectations .2當(dāng)水源緊張的時(shí)候，滿意的辦法是節(jié)省用水，并把有限的水用在滿足高峰需求階段的發(fā)電上。When water is in short supply, it is desirable to use the limited available potential energy sparingly,for periods of short duration,to meet the peak-load demands.3煤發(fā)電廠和其它化石發(fā)電廠一樣存在著嚴(yán)重的環(huán)境問題，如酸雨和溫室效應(yīng)等。Co

38、al-fired plants share environmental problems with some other types of fossil-fuel plant:these include acid rain and the greenhouse effect.4現(xiàn)代類型的避雷器具有很平坦的E-I特性， 這使我們可以降低安裝變電站設(shè)備的BIL標(biāo)準(zhǔn)，從而節(jié)省了大量成本。Modern type of arrester with very flat E-I characteristics also enable us to reduce the BIL requirements of

39、apparatus installed in substation, which saves a lot of cost .5計(jì)算機(jī)輸入可以由人、環(huán)境或其它計(jì)算機(jī)來進(jìn)行。這種輸入包括字符、計(jì)算數(shù)據(jù)、圖片、聲音信號或程序指令等。Computer input can be supplied by a person,by the environment or by another computer . Examples of the kinds of input include the words and symbols in a document,numbers for a calculation

40、,picture,temperatures from a thermostat,audio signals from a microphone,and instructions from a computer program. 6. In fact, the law of conservation of energy must be obeyed in any electric circuitFor this reason, the algebraic sum of power in a circuit, at any instant of time, must be zero.事實(shí)上，任何電

41、路必須遵守能量守恒定律，在任意瞬間電路中功率的代數(shù)和恒為零。3. The basic requirement to a power system is to provide an uninterrupted energy supply to customers with acceptable voltages and frequency. Because electricity can not be massively stored under a simple and economic way, the production and consumption of electricity mu

42、st be done simultaneously.對電力系統(tǒng)的基本要求是以可接受的電壓和頻率給用戶提供不間斷的電能供應(yīng)。由于電能不能以簡單和經(jīng)濟(jì)的方式大量儲(chǔ)存，電能的生產(chǎn)和消費(fèi)必須同時(shí)完成。4. The rotating magnetic field is essential to the functioning of an induction motor. In practical machines this rotating magnetic field is achieved by a combination of a space displacement of the winding

43、s and a time-phase displacement of the exciting voltage.就感應(yīng)電動(dòng)機(jī)的工作而言，旋轉(zhuǎn)磁場是非常重要的。在實(shí)際的電機(jī)中，旋轉(zhuǎn)磁場是通過空間上交替布置的繞組和時(shí)間相位上相互交替的勵(lì)磁電壓來實(shí)現(xiàn)的。5. The unit just described, with pulverized coal, air, and water as an input and steam as a useful output, is variously called a steam generating unit, or furnace, or boiler.上面

44、描述的以煤粉、空氣和水作為輸入以蒸汽作為輸出的單元可以叫做蒸汽發(fā)生單元、鍋爐和蒸發(fā)器。6. A variation of the speed from the desired value, due to a change of mechanical load on the shaft, can in no way cause a change in the value of the applied armature voltage to maintain the desired speed.甲從所需的值的速度的變化，由于在該軸上的機(jī)械負(fù)載的變化，可以以任何方式造成的變化在所施加的電樞電壓的值，

45、以保持所需的速度。2除了以上提到的那些基本設(shè)備之外，計(jì)算機(jī)還可以增加很多附屬設(shè)備以增強(qiáng)自己的功能，如數(shù)碼相機(jī)，掃描儀。In addition to these equipment mentioned above,some other peripheral devices might be added to a computer system to enhance its functionality,such as a digital camera,scanner. 3在實(shí)際變壓器中是可以構(gòu)建一個(gè)等效電路來分析它主要的不足的。It is possible to construct an equi

46、valent circuit that takes into account all the major imperfections in real transformers.4當(dāng)開關(guān)閉合的時(shí)候，電流開始直線升高到Is，此時(shí)二極管V1處于通電狀態(tài)。When the switch is closed , the current begins to build up linearly to Is while the diode V1 is still on. 5一個(gè)現(xiàn)代類型的避雷器具有用層疊狀的鋅氧化物碟片做成的閥塊，其間沒有采用任何空氣間歇。A modern type of arrester h

47、as valve blocks made of stacked zinc oxide discs without using any air gaps.1In induction motors the rotating magnetic field is set up by windings in the stator, and the induced currents are carried by conductors in the rotor.在感應(yīng)電動(dòng)機(jī)中，旋轉(zhuǎn)磁場是由定子繞組產(chǎn)生的，感應(yīng)電流通過轉(zhuǎn)子中的導(dǎo)體傳遞。2. The desirable feature of hydropowe

48、r in effectively meeting peak demand may be obtained in locations without suitable water flows by using pumped storage. (5分)理想的功能可以得到有效地滿足需求高峰的水電位置沒有合適的水流量使用抽水蓄能電站。3. Copper disk will rotate with magnetic field in the same direction, but it will never reach the rotating speed of the magnetic field,

49、because if it did, there would be no relative motion that results of inductive current.銅盤將以旋轉(zhuǎn)磁場方向相同的方向轉(zhuǎn)動(dòng)，但它卻達(dá)不到旋轉(zhuǎn)磁場的轉(zhuǎn)速，因?yàn)槿绻悄菢樱鼈冎g就不會(huì)有相對運(yùn)動(dòng)所產(chǎn)生的感應(yīng)電流。4. The successful operation of space vehicles, the space shuttle, space stations, and re-configurable flight control systems depends on the proper funct

50、ioning of the large number of control systems used in such ventures.航天器，航天飛機(jī)，空間站和可重新配置的飛行控制系統(tǒng)的成功運(yùn)作，依賴于這樣的企業(yè)中使用大量的控制系統(tǒng)的正常運(yùn)作。5. In every aspect of our increasingly technological societywhether it is science, engineering, medicine, music, maintenance, or even espionagethe role of electronics is large,

51、and it is growing.在日益發(fā)展的科技社會(huì)中的每一方面，無論是科學(xué)、工程、醫(yī)學(xué)、音樂、維修，甚至是諜報(bào)，電子學(xué)的作用都是非常大的，而且越來越重要。6. The stop valve has a protective function; it is normally fully open but can be “tripped” shut to prevent over-speed of the turbine-generator unit if the electrical output drops suddenly.關(guān)斷閥門起一個(gè)保護(hù)作用，正常時(shí)它是全開的，如果電氣輸出功率突然

52、降低，它可以突然關(guān)斷以防止汽輪發(fā)電機(jī)超速。7. We can proceed to our simplification of sinusoidal steady-state analysis by establishing the relationship between the phasor voltage and phasor current for each of the three passive elements.通過建立三種無源元件各自的電壓相量和電流相量之間的關(guān)系，我們可以對正弦穩(wěn)態(tài)分析進(jìn)行簡化。. Translate (Chinese to English): (15 mar

53、ks, 5 marks for each item)1. 信號是這樣一種物理量：隨著時(shí)間的變化，其大小或差值包含有信息。A signal is any physical variable whose magnitude or variation with time contains information.2計(jì)算機(jī)軟件幫助你管理文件、裝載數(shù)據(jù)、執(zhí)行應(yīng)用程序，并且從鼠標(biāo)和鍵盤接收你的命令。Computer software helps you to manage your files , to load and execute programs , and to accept your comm

54、ands from the mouse and keyboard .3雖然我們現(xiàn)在知道，在金屬導(dǎo)體中，電流是由負(fù)電荷電子引起的，但我們依然采用廣泛接受的習(xí)慣：電流是正電荷的凈流動(dòng)。Although we now know that the current in metallic conductors is due to negatively charged electrons,we will follow the universally accepted convention that current is the net flow of positive charges. 2. Curren

55、t direction and voltage polarity play a major role in determining the sign of power. It is therefore important that we pay attention to the relationship between current i and voltage u in Fig.1-3.2。電壓極性和電流極性決定功率的符號。因此需要關(guān)注圖1-3（a）中的電壓u與電流i之間的關(guān)系。5. Some arresters are composed of an external porcelain t

56、ube containing an ingenious arrangement of stacked discs, air gaps, ionizers, and coils.某些避雷器外部瓷管含有一個(gè)巧妙的安排層疊光盤，空氣間隙，靜電消除器，和線圈組成1. 電力系統(tǒng)的穩(wěn)態(tài)運(yùn)行經(jīng)常被電氣設(shè)備的各種故障或外部因素如自然災(zāi)害等所干擾。Steady-state operation of the power system often interfere with electrical equipment failure or external factors such as natural disas

57、ters .2計(jì)算機(jī)是有多種功能的機(jī)器，可以完成很多種任務(wù)，但有些類型的計(jì)算機(jī)則是為一些專門任務(wù)設(shè)計(jì)的，如工作站。Computer are versatile machine,which are able to perform a truly amazing assortment of tasks, but some types of computer are better suited to certain tasks ,such as work station. 3在非高峰用電期間，發(fā)電機(jī)充當(dāng)電動(dòng)機(jī)運(yùn)行，通過水輪機(jī)把水相反地從低處抽到蓄水庫中。During off-peak times,

58、the generators, operating as synchronous motors, in this scheme water is pumped from a lower reservoir to a higher one. 4今天，自動(dòng)控制系統(tǒng)滲透到社會(huì)生活的各個(gè)方面，并且在促進(jìn)經(jīng)濟(jì)發(fā)展和技術(shù)進(jìn)步方面起到催化劑的作用。Today , the automatic control system penetrated into all aspects of social life , and act as a catalyst in promoting economic develo

59、pment and technological progress .5電力變壓器是由一到兩種鐵芯構(gòu)成的。在其中一種結(jié)構(gòu)類型中，線圈纏繞在由簡單的鋼片組成的矩形框架的兩端。The power transformer is constituted by one to two kinds of cores . In one type of the structure , the coil is wound at both ends of the rectangular frame composed by a simple steel .2. Hydroplants are classified as high head (over 100 ft) and low head. The head refers to t