信息科学与电子工程专业英语课后答案

U n i t1E x e r c i s e s(1)T r a n s l a t e t h e f o l l o w i n g s e n t e n c e s i n t o C h i n e s e. 1.As with series resonance, the greater theresistance in the circuit the lower the Q and,accordingly, the flatter and broader theresonance curve of either line current or circuitimpedance.对于串联谐振，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 sameand 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 tochange the pulse repetition rate, or directly entera new value of the period in the provideddialogue box, while keeping the pulse widthunchanged.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期值，而保持脉冲宽度不变。

4.Electronics is the science and the technology of the passage of charged particles in a gas, in a vacuum, or in a semiconductor. 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 processing 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，而软件及数字处理面却没能与硬件同步发展。

6.However, in a properly designed DC amplifier theeffect of transistor parameter variation, otherthan Ico, may be practically eliminated if theoperation point of each stage is adjusted so that it remains in the linear operation range of thetransistor 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。

U n i t2E x e r c i s e s(1)T r a n s l a t e t h e f o l l o w i n g s e n t e n c e s i n t o C h i n e s e. 1.If analog signals are to be transmitted digitally,they first have to be sampled at a specified rateand further converted to discrete amplitudesamples by quantization.如果要以数字式传输模拟信号，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 spatialfrequencies, can achieve such effects assmoothing and sharpening, and usually form thebasis 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。

3.Stability and repeatability are fundamental attributes of digital circuits, however, and the necessary accuracy can be obtained in 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 continuous 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期性之间的基本关系中首先可以看到：连续系统有非期性的频率响应，而离散系统有期性的频率响应。

5.The main function of the receiver is to extract theinput message signal from the degraded version of the transmitted signal coming from thechannel.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。

Unit 3 Exercises(1)T r a n s l a t e t h e f o l l o w i n g s e n t e n c e s i n t o C h i n e s e. 1.A very commonly used method of microwavemeasurements is based on the study of astanding wave pattern formed along the linebecause of the interference of incident andreflected waves.一个很常用的微波测量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。

putations show a reduction of 6dB in the EMfield intensity with the distance doubled, and an increase of 3dB in the intensity with thetransmitted power doubled. This result providesverification 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, convectionand radiation, microwave heating can beconsidered as another mode of heat transfer, in which heat is produced directly at the 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式，即热量直接产生于发生介电损耗的地。

4.Operation of the radar is based on themeasurement of the time it takes for a pulsetransmitted from an antenna to get reflected by the object to be detected and to return at theantenna and the receiver.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 designincludes the wish to acquire confidence in adesign 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CAD的其它动机包括：想要验证用别的法设计出来的电路；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）6.The spacing between the repeating amplifiers isa function of the cable attenuation and thesystem bandwidth so that the gain provided by these amplifiers compensates for the lossintroduced 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。