科技英语课文,Lesson Two,Text A Question What is transmitter? The use of telecommunication and radar transmitter? What kind of signal should be sent out to detect object?,To do 做表语,The use of a telecommunications transmitter is to transmit intelligence by radio. 无线电发射机的用途是用无线电来发送信息。 练习 这本书的目的在于介绍物理学的初步知识 发电机的用途是将机械能转化为电能。,The purpose of this book is to provide an introduction to physics. 这本书的目的在于介绍物理学的初步知识。 （想想：同样的意思可以用serve to 来表示么？） The use of generator is to convert mechanical energy into electrical energy. 发电机的用途是把机械能转换为电能。,区别： 1、We are to discuss this point in detail in the next chapter. 我们将在下一章详细讨论这一点。 这里的to do 是表示 计划要发生的事。,To do 做定语,A transmitter is an equipment to send out radio waves. 发射机是能发射无线电波的一种设备。 练习 能发射无线电波的天线称为发射天线。 能量就是做功的能力,The antenna to transmit radio waves is called a transmitting antenna. 能发射无线电波的天线称为发射天线。 Energy is the power to do work. 能量是做功的能力,To do 做补足语,A potential difference is necessary to cause electrons to flow along a conductor. 电位差是为使电子沿导体流动所必需的。 练习 计算机能帮我们管理工厂。,by means of We analysis the problem by means of an example.我们通过一个例子来分析这一问题。 This paper analyses operation accuracy that is influenced by the open inputresistance of operation amplifier by means of superposition theorem. 本文应用叠加原理分析运算放大器的开环输入电阻对反相比例放大运算精度的影响。,Lesson Three,Text A Question What is time constant? How to compute time constant? How to compute the time for a capacitor to rise to a certain voltage? 翻译 电容充满电所需要的时间,动词不定式复合结构,The time for the capacitor to become fully charged depends on the product of circuit resistance and capacitance. 使电容器充满电的时间取决于电路里电阻和电容的乘积。 练习： 阳光到达地球需要花费大约8分钟的时间。 应该要有消耗能量的某种方式。 (消耗：dissipated),应该要有消耗能量的某种方式。 There should be a way for the energy to be dissipated. 阳光到达地球需要花费大约8分钟的时间。 It takes about 8 minutes for sunlight to reach the earth.,名词性不定式,How to determine the weight and size of an atom is a question interesting to many of us. 如何测定原子的重量和体积是很多人感兴趣的一个问题。 We should know how to charge or discharge time of a capacitor. 我们应该知道如何来计算电容器充电或放电的时间。 练习 计算机必须被告知如何解给定问题的办法,计算机必须告知如何解给定问题的办法 The computer must be told how to solve any given problem.,Lesson Four,Text A Question What is resistivity? What does the greater resistivity mean? Translation 类似的程度 E和J之比 把电阻率定义为,participle 分词,present participle and past participle,分词,Metals and alloys having the lowest resistivities are the best conductors. 具有低电阻率的金属和合金是最好的导体。 A capacitor is a device consisting of two conductors separated by a non-conductor. 电容器是一种由被非导体分隔开的两个导体组成的器件。,分词作定语,这些运动的电子形成电路 These moving electrons form the current. 练习： 携带信息的无线电波到达无线电接收机的天线端。 电能是世界上使用最为广泛的能量形式之一。,携带信息的无线电波到达无线电接收机的天线端。 The radio waves carrying intelligence reach the antennas of radio receivers. 电能是世界上使用最为广泛的能量形式之一。 Electric energy is one of the forms of energy most widely used in industry.,Lesson Five,Text A Question What is Lenzs law? What is the two important properties of an alternating electric circuit? Translation 阻碍电流的变化 总结 带电流的导体,分词作状语,Expressed in a formula, the relationship between voltage,current and resistance in a circuit can be written as V=IR. 若用公式来表示，电路中的电压电流电阻之间的关系可以写成V=IR。,分词在句末,The current decreasing, an emf is induced in the direction coinciding with that of the current,thus opposing the decrease of curent. 当电流减小时，则在与电流方向相同的方向上感应出一个电动势，从而阻止电流的减小。 （这里，The current decreasing 是分词独立结构。）,因为有大量的自由电子，金属是良导体。 Having a large number of free electrons, metals are good conductors. 我们可以用基尔霍夫电流电压定理来写电路网络的微分方程。 We can write the differential equations of the network using Kirchhoffs current and voltage laws.,Lesson Six,Text A Question What is tuning? What is the three functions of a tuning circuit? Translation 串联调谐电路 排斥其他信号 处于最小值,动名词,介词宾语 This may be accomplished by adjusting one or more components of a series tuned circuit. 作主语 Selecting a desired signal is one of three important functions performed by the tuning circuit.,动名词,.作宾语 A magnetic field is formed around a wire when a current starts flowing in it. 作表语 The use of rectifier is transforming AC into DC.,Lesson Seven,Text A Question What does Ohms law say? What can we do by means of Ohms law? Translation 线两端的电压 与电压成正比 保持不变,同位语从句,Ohm made the discovery that a simple correlation exists between resistance,current and voltage. 欧姆发现电阻，电流和电压之间存在简单的关系。,状语从句,Provided the resistance of a wire is constant, the current passing through it is proportional to the potential difference maintained, as long as the temperature of the conductor remains unchanged. 如果导体的电阻不变，则通过它的电流与所维持的电位差成正比，只要导体的温度保持不变。,Lesson Eight,Text A Question What must a receiver do? Why television receivers discuss separately? What is the major difference between receivers of various type. Translation 一定程度的标准化 恢复原来的调制电压,名词从句,It has been well known that the signal received is generally quite weak. 众所周知，接收到的信号是十分微弱的。 This chapter will show why their format has been to a certain extent standardized. 本章将讨论为什么它们的形式在一定程度上已经标准化。,名词从句,It is apparent that a receiver has the function of selecting the desired signal from all the other undesired signals. 显而易见，接收机具有