1、科技英语课件 Exercises HMILYYLIMH 1 Unit 1 Exercises (1) Translate the following sentences into Chinese. 1. As with series resonance, the greater the resistance in the circuit the lower the Q and, accordingly, the flatter and broader the resonance curve of either line current or circuit impedance. 对于串联谐振，
2、电路中的电阻愈大 Q 值就愈低，相应地线路电流或电路阻抗的谐振曲线也就愈平、愈宽。 2. A wire carrying a current looks exactly the same and weighs exactly the same as it does when it is not carrying a current. 一根带电的导线其外表与重量都与不带电导线完全一样。 3. Click mouse on the waveform and drag it to change the pulse repetition rate, or directly enter a new va
3、lue of the period in the provided dialogue box, while keeping the pulse width unchanged. 在波形上点击鼠标并拖动来改变脉冲重复频率，或者在提供的对话框中直接输入新的周期值，而保持脉冲宽度科技英语课件 Exercises HMILYYLIMH 2 不变。 4. Electronics is the science and the technology of the passage of charged particles in a gas, in a vacuum, or in a semiconductor
4、. Please note that particle motion confined within a metal only is not considered electronics. 电子学是一门有关带电粒子在气体、真空或半导体中运动的科学技术。注意，在本书中粒子运动仅限于金属的情况不属于电子学。 5. Hardware technologies have played vital roles in our ability to use electronic properties to process information, but software and data processi
5、ng aspects have not developed at the same speed. 硬件技术在我们使用电子特性来处理信息的能力中一直起着重要作用，而软件及数字处理方面却没能与硬件同步发展。 6. However, in a properly designed DC amplifier the effect of transistor parameter variation, other than Ico, may be practically eliminated if the operation point of each stage is adjusted so that i
6、t remains in the linear operation range 科技英语课件 Exercises HMILYYLIMH 3 of the transistor as temperature varies. 然而在设计得当的直流放大器中，若调节每一级的工作点使之在温度变化时 保持在晶体管线性区，就能在实际上消除 Ico 以外的晶体管参数变化所造成的影响。 Unit 2 Exercises (1) Translate the following sentences into Chinese. 1. If analog signals are to be transmitted di
7、gitally, they first have to be sampled at a specified rate and further converted to discrete amplitude samples by quantization. 如果要以数字方式传输模拟信号，首先必须以一定的频率对信号进行采样，然后通过量化进一步将它们转换为离散的幅度样本。 2. Linear filters amplify or attenuate selected spatial frequencies, can achieve such effects as smoothing and shar
8、pening, and usually form the basis of re-sampling and boundary detection algorithms. 线性滤波器放大或衰减选择的空间频率，能够实现像平滑和锐化这些效果，通常是重采样和边缘检测算法的基础。 科技英语课件 Exercises HMILYYLIMH 4 3. Stability and repeatability are fundamental attributes of digital circuits, however, and the necessary accuracy can be obtained in
9、a digital version of the modulator by an appropriate choice of word length to represent the signals. 不过稳定性和可重复性是数字电路的基本性质，在数字式调制器中必要的精度可通过适当地选择代表信号的字长而获得。 4. The first observation is made on the fundamental relationship between the nature of system and the periodicity of its frequency response: a co
10、ntinuous system has an aperiodic frequency response, while a discrete system has a periodic frequency response. 从系统性质和它频率响应的周期性之间的基本关系中首先可以看到：连续系统有非周期性的频率响应，而离散系统有周期性的频率响应。 5. The main function of the receiver is to extract the input message signal from the degraded version of the transmitted signal
11、 coming from the channel. 接收器的主要功能是从由信道传输来的退化了的信号中提取出输入消息。 科技英语课件 Exercises HMILYYLIMH 5 Unit 3 Exercises (1) Translate the following sentences into Chinese. 1. A very commonly used method of microwave measurements is based on the study of a standing wave pattern formed along the line because of the
12、 interference of incident and reflected waves. 一个很常用的微波测量方法是基于对驻波图型的研究，这种驻波是由入射波和反射波之间的干涉而沿着传输线形成的。 2. Computations show a reduction of 6dB in the EM field intensity with the distance doubled, and an increase of 3dB in the intensity with the transmitted power doubled. This result provides verificati
13、on to the algorithm used. 计算表明，当距离增大一倍时，电磁场强度减小 6 分贝；而发射功率增大一倍时，场强则增加 3 分贝。这一结果验证了所用算法的正确性。 3. Like transfer of heat by conduction, convection and radiation, microwave heating can be considered as another mode of heat transfer, in which heat is produced directly at 科技英语课件 Exercises HMILYYLIMH 6 the
14、location of the dielectric losses. 就像通过传导、对流、辐射来传递热量一样，微波加热可以看作热传递的另一种方式，即热量直接产生于发生介电损耗的地方。 4. Operation of the radar is based on the measurement of the time it takes for a pulse transmitted from an antenna to get reflected by the object to be detected and to return at the antenna and the receiver.
15、雷达的工作是基于对天线发出的脉冲被所要探测的目标反射，（然后）回到天线和接收机所需时间的测量。 5. Other motivations for using CAD in circuit design includes the wish to acquire confidence in a design that was accomplished by other means, and, not least in importance, a sense of curiosity or perhaps a desire to discover the unexpected. 在电路设计中使用 C
16、AD 的其它动机包括：想要验证用别的方法设计出来的电路；满足好奇心或者可能是想发现预想不到的现象。后一个动机并非是最不重要的。（取得信心，并非 最不重要，意料之外的事） 科技英语课件 Exercises HMILYYLIMH 7 6. The spacing between the repeating amplifiers is a function of the cable attenuation and the system bandwidth so that the gain provided by these amplifiers compensates for the loss in
17、troduced by the cable. 中继放大器之间的间距是电缆衰减和系统带宽的函数，以便这些放大器提供的增益补 偿电缆引起的损耗。 7. When the cut-off frequency is no less than the maximal frequency of the original signal, nor is it greater than the difference between the sampling frequency and the maximal frequency, the original signal may be completely reb
18、uilt. 当截止频率不小于原始信号的 最高频率，也不大于采样频率和最高频率之差，原始信号可以完整地重建。 8. While the politics of the last one hundred years centered around Industrial Age technology, the politics of the future will be based on Information Age concerns oriented towards the storage, protection and exchange of information. 尽管近百年来的政治活动是
19、以工业时代的技术为中心的，未来的政治活动将基于信息时代的事物，面向信息科技英语课件 Exercises HMILYYLIMH 8 的存储、保护和交换。 Unit 4 Exercises (1) Translate the following passages into Chinese. 1. Communication may be broadly defined as the transfer of information from one point to another. When the information is to be conveyed over any distance a
20、 communication system is usually required. Within a communication system the information transfer is frequently achieved by superimposing or modulating the information on to an electromagnetic wave which acts as a carrier for the information signal. This modulated carrier is then transmitted to the
21、required destination where it is received and the original information signal is obtained by demodulation. Sophisticated techniques have been developed for this process by using electromagnetic carrier waves operating at radio frequencies as well as microwave and millimeter wave frequencies. However
22、, communication may also be achieved by using an electromagnetic carrier that is selected from the optical range of frequencies. 通信可以 广义地定义为从一处到另一处的信息传递。当科技英语课件 Exercises HMILYYLIMH 9 要将信息传输到任何距离以外时就需要有一个通信系统。在通信系统内部，信息的传输经常通过将信息叠加或调制到作为信号载体的电磁波上来实现。经调制的载波然后被传送到要求的目的地，在那里被接收，原始信号通过解调被恢复出来。为了实现这一过程，已
23、经利用工作在射频、微波以及毫米波频率上的电磁载波开发了复杂的技术。不过通信也可以用光波频段上的电磁载波来实现。 2. Electronic communications is the transfer and movement of data between locations through the use of computers. An electronic communication system includes the equipment needed to support the movement of information, the communication lines a
24、nd media to carry the information, the computer software and programs to control the flow of information, the personnel to plan, implement, and operate communications, and the management of all these resources. Electronic communications establishes links between people as well as computers. 电子通信就是通过
25、使用计算机在不同的地点之间传输数据。一个电子通信系统包括：支持信息流动所需要的设备，承载信息的通信线路和媒介，控制信息流的计算科技英语课件 Exercises HMILYYLIMH 10 机软件和程序，计划、实施、操作通信系统的人员，以及对所有这些资源的管理。电子通信建立起人和人、计算机和计算机之间的联系。 3. First generation communications systems can be characterized by the use of analog transmission techniques, and the use of simple multiplex acc
26、ess techniques such as frequency division multiple access (FDMA). They suffered from a low user capacity, and security problems due to the simple radio interface used. Second generation systems were introduced in the early 1990s, and all use digital technology. This provided an increase in the user
27、capacity of around three times, achieved by compressing the voice waveforms before transmission. Third generation systems are an extension on the complexity of second-generation systems and are to be introduced after the year 2000. The system capacity will be increased to over ten times original first generation systems, achieved by using complex multiplex access techniques such as code division multiplex access (CDMA), or an extension of TDMA, and by improving flexibility of services available. 第一代通信系统以模拟传输技术和简单复用技术如频
