测控技术与仪器专业英语 张凤登UNIT-6.Amplifiers

UNIT 6 Amplifiers,6.1 Text Distinction between Voltage and Current Amplifiers 电压放大器与电流放大器的区别,Table 6-1 Source and load resistance considerations in voltage and current amplifiers, rin: the input resistance of an amplifier. rout: the output resistance of an amplifier.,New Words distinction n. 区别；差别 stage n. （放大）级 substantially ad. essentially, 基本地；实质上 overall a. 总的；综合的 decibel n. 分贝 deduce v. reach a conclusion, 推论 precaution n. measure, 预防措施 distortion n. 失真 inherently ad. 本质上，生来 shunt v. 使并联,Exercises 1. Answer the following questions. The input resistance of the amplifier must be high compared with the resistance of the signal source. The output resistance must be low compared with load resistance. The overall voltage gain of the amplifier can be given. Yes, there is. When expressed in decibels, it can be added to give the overall gain of the amplifier. The input resistance of the amplifier must be small compared with the resistance of the signal source. The output resistance of the amplifier must be high compared with the load resistance. The overall current gain of the amplifier can be given. Yes, there is. When expressed in decibels, it can be added to give the overall gain of the amplifier. A given amplifier can behave as a voltage or current amplifier. The advantage of using FET as voltage amplifier is that the transistor has a high input resistance and works with little power.,Exercises (continue) 2. Choose the right words or phrases and change them into appropriate forms if necessary to replace the underlined parts in the following. reaches a conclusion essentially is composed of developed In fact adjusted rests on In spite of powered be put into use in,6.2 Reading and Translation Amplifying System Functions 放大系统的功能,New Words and Phrases regardless of 不注意，不顾 stereophonic ,stiu'fnik a. 立体声的（stereo） cartridge 'k:trid n. （唱片）拾音器，卡盘 amplitude 'æmplitju:d n. magnitude, 幅度 deck dek n. （录音机）走带机构 RF abbr. radio frequency, 射频 RF voltage signals 射频电压信号,斜体部分参考译文: Microphones, phonograph pickup cartridges, and tape-recorder head are typical input transducers. Input signals may also be received through the air. Antenna coils and networks serve as the input transducer for this type of system. An antenna changes electromagnetic waves into radio-frequency (RF) voltage signals. The signal is then processed through the remainder of the system. 话筒、唱机拾音器和磁头是典型的输入传感器。输入信号也可通过空气接收。天线线圈和天线网络就是这类系统的输入传感器。天线把电磁波变换成射频电压信号，这信号然后由系统的其余部分处理。 Work is performed by the speaker when it achieves this function. Lamps, motors, relays, transformers, and inductors are frequently considered to be transducers. An output transducer is also considered to be the load of a system. 换能功能完成，扬声器就完成了工作。电灯、电机、继电器、变压器和电感器都常被认为是换能器。输出换能器还被看作是系统的负载。 In most amplifying systems, ac is the primary energy source. Ac is changed into dc, filtered, and in some systems regulated before being applied to the amplifiers. The reproduction quality of the amplifier is very dependent on the dc supply voltage. Some portable stereo amplifiers may be energized by batteries. 在大多数放大系统中，交流是主要的能源，然后由交流变直流、滤波、在有些系统中还需稳压，然后用于放大器。放大器的放大质量很依赖直流电源电压，一些便携立体声放大器可由电池供电。,6.3 Further Reading Operational Amplifiers 运算放大器,New Words modular 'mdjul a. 制成标准组件的 differential ,dif'renl a. 差分的，差动的；微分的 octave 'ktiv n. 倍频程 decade 'dekeid n. 十 approach 'prut v. 探讨；接近 embrace im'breis v. 包括 integral 'intirl n. a. 积分；积分的,Notes roll off 转折 , the precise function being dictated by the components, and circuit arrangement of a negative feedback loop. ，其正确功能系由负反馈电路的元件和电路安排来支配。 The use of a circuit such as the op-amp comparator should be quite evident in digital work. 很显然，在数字电路的工作中将使用运算放大器比较电路。,6.4 General Knowledge 科技英语翻译标准 科技文献作为现代科学技术的载体之一，主要是述说事理、描写现象、推导公式和论证规律。因此，其特点是行文规范，表达自然，用词考究，极少修辞。科技文献中作者个人风格体现较少，感情色彩罕见，翻译时多要求逻辑思维，注重语言规范和表达准确。这就是说，科技文体的总体功能和特点与其他文体有明显不同，其翻译标准也就应与其它文体有所区别。 关于翻译的质量标准，在众多的观点中，影响最大的莫过于严复最早倡导的“信、达、雅”三原则，该三原则至今仍被人们奉为指导翻译实践、鉴定翻译成败和评价译文优劣的经典标准。从广义上讲，翻译标准的“信、达、雅”三原则适用于一切翻译活动。但是，大量翻译实践表明，对于英语科技文献，其翻译标准在具体要求上应有所侧重和扩展。 “信”，即忠实于原文，也就是完整地再现原文的内涵和思想。 “达”，即通顺，亦即通过流畅、逻辑的语言表达原文。只追求忠实而不顾通顺，弄得译文味同嚼蜡，也不是标准的翻译。 “雅”，即在忠实和通顺的基础上还应注意“文采”。翻译要讲修辞，以使译文逻辑严谨而流畅，语言优美而易懂。否则会因“言之无文，行之不远”而失去读者。 “捷”，即希望有较高的翻译速度。速度越快, 获取的信息量越大, 效率也越高。,课后作业 P.51，Exercise 3,