专业英语15.docx

1、专业英语15-1.1new words and expressions-element元件interconnect 使互相连接node 节点branch分流loop回路;topology 布局configuration配置terminal终端;接线端resistor 电阻器independent 独立自由者;不受约束series 串联parallel 并联impedance 阻抗 全电阻theorem 定理 法则To differentiate between a circuit and a network, we may regard a network as an interconnect

2、ion of elements or devices, whereas a circuit is a network providing one or more closed paths.为了区别网络和电路，可以认为网络是若干元件或装置的相互连接，而电路则是指具有一个或多个闭合路径的网络。If a short circuit (a connecting wire) connects tow nodes ,the tow nodes constitute a single node.如果2个节点间用一根短路线连接，则此2个节点构成1个单节点。The 2 resistor, the 3 resis

3、tor, and the current source are in parallel because they are connected to the same tow nodes(b and c) and consequently have the same voltage across them.2电阻、3电阻和电流源是接在相同的两个节点（b和c）上，即这3个元件是并联连接的，因此各元件上的电压相同。The sign on each voltage is the polarity of the terminal encountered first as we travel around

4、 the loop. We can start with any branch and go around the loop either clockwise or counterclockwise. Suppose we start with the voltage source and go clockwise around the loop as shown; then voltages would be v1,+v2,+v3,-v4, and +v5,in that order.顺着环路来看，每个电压的符号就是首先遇到的端子的即兴。绕行回路可以从任一支路开始，绕行方向可以顺时针，也可以

5、是逆时针。假设我们从电压源开始，顺时针绕环路一圈，那么按顺序的电压取值分别为v1,+v2,+v3,-v4,-v5。-1.2new words and expressions-analog 模拟digital 数字thermometer 温度计Fahrenheit华氏温度计drum 鼓声discrete离散的 不连续的 original 原始的 独创的 原物 原作remote 偏僻的 细微的bulb 电灯泡pulse 脉冲buzzer 蜂鸣器manipulate操纵；操作；destination 目的文件humidity 湿气 潮湿 湿度interface 界面comparator 比较仪tri

6、gger 触发sequence 顺序 序列serial 串行decoder 解码器reassemble 重新集合Digital quantities vary in discrete levels. In most cases, the discrete levels are just two valuesON and OFF. Digital systems carry information using combinations of ON OFF electrical signals that are usually in the form of codes that represent

7、 the information.数字量是离散变化的，。在大多数情况下，离散信号只有两种状态：导通和截止。数字系统通过导通和截至的电信号组合来表示信息，通常以编码的形式反映出来。The sender keeps the same shorter time interval between letters but a longer time interval between words. This allows the receiver to identify that the code sent is a character in a word or the end of a word its

8、elf. The T is one dash(one long current pulse). The H is four short dots(four short current pulses). The R is a dot-dash-dot. And the two Es are a dot each. The two states are ON and OFF current or no current.发送者在字母之间保持着相同的较短时间间隔，而在词之间保持较长时间间隔。在词之间保持较长时间间隔。这就使接收者能分辨出传送码是一个词中的字符，还是一个单词本身的结束。T是一个破折号（一

9、个长电流脉冲）。H是4个短点（4个短电流脉冲）。R是点-破折号点的组合。两个E时，则一个点代表一个E。高低两种状态表示导通和截止，即有电流和无电流。In many cases, digital signals, either at discrete levels, or changing between discrete levels, must occur precisely at the proper time or the digital system will not work. Timing is maintained in digital systems by circuits c

10、alled system clocks. This is what identifies a digital signal and the information being processed in a digital system.在许多情况下，数字信号，无论是在离散电平，还是在离散电平间变化，都必须准确地发生在合适的时间，否则数字系统将无法正常工作。通过被称为系统时钟的电路来维持数字系统的计时。这就是在数学系统中识别数字信号和处理数字信息。To maintain an accuracy of 0.1% or 1 part in 1000 is difficult with an anal

11、ong instrument.在使用模拟量仪器进行测量时，要维持0.1%或1%的误差是很困难的。Using 12 bits gives four times the accuracy(1 part in 4096),and using 16 bits gives an accuracy of 0.0015%,or 1 part in 65536.使用12进位时，精度是其4倍（1/4096），而使用16进位的精度则是0.0015%（或1/65536）.-1exercises-(1)An ac voltage source V in series with an impedance Z can b

12、e replaced with an ac current source of value I=V/Z in parallel with the impedance Z.(1)一个交流电压源V与一个阻抗Z相串联，可以被替换成一个值为I = V / Z的交流电流源与阻抗Z相并联。(2)Although current and voltage are the two basic variables in an electric circuit, they are not sufficient by themselves. For practical purposes, we need to kno

13、w how much power an electric device can handle.(2)虽然电流和电压是电路中的两个基本变量，但是它们本身并不足够.。出于实用的目的，我们需要知道一个电气设备可以处理多大的功率.。(3)In any linear circuit containing multiple independent sources, the current or voltage at anypoint in the network may be calculated as the algebraic sum of the individual contributions o

14、f each source acting alone.(3)在包含多个独立源的线性电路中，某处电流或电压都是电路中各个独立源单独作用时，在该处分别产生的电流或电压的叠加。(4)Since an 16-bit code can represent 65536 quantities. The first bit at the right edge of the code is called the least significant bit(LSB). The left-most bit is called the most significant bit(MSB).(4)一个16位代码可以表示6

15、5536数量。代码右边第一位称为最低有效位（LSB）。最左边的位是最高有效位（MSB）。(5)Since an 8-bit code can represent 256 segments, is codes for the same analong value are shown with the maximum analong signal of 1.5V equal to 255. Notice that the 8-bit code is two groups of 4-bit codes, which are also expressed in hexadecimal form. (5

16、) 由于一个8位代码可以表示256个字段，以此表示的代码对应的模拟值，最大的模拟信号1.5V取值为255。另外，8位代码是两组4位代码， 也以十六进制形式表示。(6)After the digital processing system completes its manipulation of the signal, the output digital codes are coupled to a digital-to-analong converter that changes the digital codes back to an equivalent analong signal.

17、(6) 数字处理系统完成对信号的处理后，输出数字码被传到数字转模拟的转换器,改变数字码为等效的模拟信号。(1)电子电路通常可以被归类为模拟电路、数字电路或混合信号电路。(1) Electronic circuits can usually be classified as analog circuits, digital circuits or mixed-signal circuits.(2)有源元件能产生能量，而无源元件不能。(2)The active element can produce energy, and passive components cant.(3)数/模转换之后所需的

18、一个基本功能是滤波。(3) A basic function required after the digital / analog conversion is filtering.(4)第一种方式并行位转移意味着数字代码的所有位在同一时间输出。(4)The first way-parallel shift means that the code of all digital output at the same time.(5)由数/模转换器接收到的数字代码等于一个特定的模拟值。(5) A basic function required by the digital / analog con

19、version is filtering.-2.1new words and expressions-solid-state 固态的computation 计算，估计integration 结合，整合，一体化dynamic 动态的，动态，动力学，活力mercury-arc 汞弧valve 阀，真空管semiconductor 半导体switching 开关，转换diode 二极管inverter 逆变器thyristor 半导体闸流管inverter thyristor 晶闸管逆变器transistor 结实的，牢固的，本质，重要材料fluorescent lamp ballast荧光灯镇流器

20、mercury 水银thermionic 热电子的HVDC transmission system高压直流输电系统induction motor 感应电动机vacuum 真空，空间dissipate 驱散rectifier 纠正者，整顿者triggered 触发的thyratron 闸流管ignitron 引燃管，导电管cycloconverter 周波变换器triac 三端双向可控硅开关元件a scope of 一个范围spectrum 光谱，能谱，范围，系列，幅度it also refers to a subject of research in electrical engineerin

21、g which deals with design，control，computation and integration of nonlinear，time varying energy processing electric systems with fast dynamics.它也是电气工程研究课题之一，主要对具有快速动态响应的非线性、时变能源处理的电子系统进行设计、控制、计算和集成。power electric converters can be found wherever there is a need to change voltage，current or frequency

22、of electric power，as showed in Fig.2.1，Fig.2.2 and Fig.2.3. The power ranger of these converters is from some milliwatts（as in a mobile phone） to hundreds of megawatts in a HVDC transmission system.对电压、电流或电能的频率进行转换时，就要用到电力电子转换器，如图2.1、2.2、2.3所示。这些转换器的功率范围从毫瓦特（如移动电话的功率）到高压直流电输电系统的数百兆瓦。the first high p

23、ower electric devices were mercury-arc valves. In modern systems the conversion is performed with semiconductor switching devices such as diodes，thyristors and transistors，as pioneered by R.D.Middlebrook and others beginning in the 1950s.第一台功率电子器件是汞弧真空管。现代功率转换系统使用半导体开关器件，如二极管、晶闸管和晶体管等，这些半导体器件都是二十世纪五

24、十年代率先由R.D.米德尔布努克等人设计发明的。-2.2new words and expressions-wafer 圆片，晶片SCR 可控硅整流器GTO 门极可关断晶闸管MCT MOS控制晶闸管IGBT 绝缘栅双极型晶体管BJT 双极结型晶体管FET 场效应管semiconductor 半导体freewheeling 惯性滑行forward-bias 正向偏置kiloamperes 千安培leakage 泄露switch 开关，转换reverse-biased 反向偏置silicon-controlled 可控硅MOSFET 金属氧化层半导体效应晶体管gigahertz 千兆赫enhanc

25、ement 增强，增加，提高drawback 缺点，不利条件withstand 经受，承受，反抗breakdown 损坏，故障，分解，衰竭the forward bias characteristic of the power diode is approximately linear，which means that the voltage drop is proportional to the Ohmic resistance and current.电力二极管的正偏特性近似于线性，也就是说电压降与欧姆电阻值以及电流成正比。therefore，attempts were made to c

26、ombine these tow types of transistor on the same silicon wafer to achieve better technical features. These investigations resulted in the development of the insulated gate bipolar transistor（IGBT）as shown in Fig.2.5（f），which is becoming the device of choice in most of most new power applications.因此，

27、为了得到更好的性能，人们尝试在同一块硅片上将两者结合，最终发明了绝缘栅双极晶体管（IGBT），如图2.5（f）所示。IGBT迅速成为很多新电力项目的首选器件。due to the negative temperature coefficient，when a temperature is raised，the power and heating decrease therefore the device withstands the overloading and operates in parallel well.由于IGBT属于负温度系数半导体材料，当温度上升时，功耗和热量会随之下降，所以

28、特别耐压，且适合并联。-2exercises-but how do you（come up with）the architecture for this evolutionary prototype？only in cities can children be well prepared for their life and（keep up with）the trend of the world.the Gaussian（approximative）method is a kind of simple and accurate computing way.many people like to

29、 stay (near) where they were born.i cannot （involve in） your future life and have no opportunity to care of you.i dont want my son to be （involve with）bad guys.more and more international meeting have been（hold in）China.the judge agreed to（hold on）making a decision until new evidence could be introd

30、uced into court.they（mostly） live on the outskirts of a town.the wheat is one of the （most） important plants to be domesticated.electric trains are a big movement in public transportation，especially in rural areas. These trains use power electronic devices to obtain power，as well as for vector contr

31、ol using pulse width modulation（PWM）rectifiers.在公共交通中，电力机车的运量很大，特别是在农村地区，这些列车使用电力电子设备获得电力，以及使用脉宽调制（PWM）整流器的矢量控制.。another new usage for power electronics is in elevator systems. These systems may use thyristors，inverters，permanent magnet motors，or various hybrid systems that incorporate PWM systems and standard motors.电力电子的另一个新的用法是电梯系统。这些系统可以使用晶闸管、逆变器、永磁电机、或采用包括PWM系统和标准电机的各种混合系统。voltage source inverters（VSIs）are named so because the independently controlled output is a voltage waveform.