1.Because of the very high open -loop voltage gain of the op-amp,the output is driven into positive saturation(close to+V)when the sample voltage goes slightly above the reference voltage ,and driven into negative saturation (close to -V)when the sample voltage goes slightly below the reference voltage.

1.由于运放的开环电压增益很高，当取样电压略高于参考电压时，输出趋向于正向饱和状态（接近+V）。当取样电压低于参考电压时，输出趋向于负向饱和状态（接近-V）。

2.Both N-type and P-type semiconductors are made by treated materials,such as germanium and silicon with impurities such as arsenic and indium.

2.N型半导体和P型半导体是利用杂质掺入纯净半导体而形成的，如将杂质砷和铟掺入锗和硅中。

3.By comparison,most other forms of transmission systems convey the message information using the shape,or level of the transmitted signal;parameters that are most easily affected by the noise and attenuation introduced by the transmission path.

3.相比之下，许多其他形式的传输系统是利用被传信号的波形或电平的高低来传送信息的，而这些参数又极易受到传输路径中的噪声和衰耗的影响。

4. Digital transmission system-embodied by telegraph systems-were developed in the 1850s before analog systems-the telephone-in the twentieth century.

4.以电报为代表的数字传输系统研发于19世纪50年代，早于以电话为代表的模拟系统，它是20世纪才开发的。

5.Depending on the relationship between the signal frequencies and the sampling rate,spectral inversion may cause the shape of the spectrum in the base and to be inverted from the true spectrum of the signal.

5.根据信号频率和采样频率之间的关系的不同，可能出现“频谱反转”现象—基带频谱的形状和信号真实频谱的形状正好相反。

6.Each element has a separate identity of its own,that is,no two elements have the same physical and chemical properties,nor can an element be subdivided by ordinary physical and chemical means into simple element.

6.每一种元素均有它自己的标识，也就是说，没有两个元素具有相同的物理和化学特性，一种元素也不能以普通的物理或化学方法被分为两种简单的元素。