宽带匹配衰减均衡器的设计

本文导出了宽带匹配衰减均衡器的等效电路及其设计公式．此均衡器提供三个通带频率的特定增益，且与信源和负载呈良好匹配。设计实例的理论预期特性与测量结果基本相符，证实了本文方法的有效性。

双模块干线放大器中衰减器、均衡器的位置对放大器指标的影响

有线电视系统中的干线传输部分主要由同轴电缆和干线放大器组成。由于同轴电缆的衰减具有随频率升高而增大的特性,在干线中,使用干线放大器提供足够的增益来补偿电缆的损耗;同时,使用均衡器来补偿电缆长距离传输引起的高、低端衰减电平差。

Study on the Attenuation Features of Earthquake Intensity in the Yunnan Region

This research on the attenuation features of intensity in the Yunnan region has been conducted by using intensity isoseismals of 127 earthquakes, and the following three conclusions have been put forward: (1) The average ratio value of long axis to short axis of innermost isoseismals in the Yunnan region is larger than that of eastern China and smaller than that of western China. The velocity of intensity attenuation varies in different directions; (2) The zoning feature of intensity attenuation in the Yunnan region is obvious; (3) In Northwest China and North China, the ratios of long axis to short axis of low magnitude isoseismals are larger than those of high magnitude ones. Compared with that phenomenon, the ratios in the Yunnan region are more complicated. Finally, some relevant questions are discussed.

利用沈阳市话线做为计算机网络通讯线路的探素

前言随着向四个现代化进军的步伐,我国电子计算机进一步广泛地利用于业务管理、信息存贮、情报检索、资料分配、作业调度和生产过程控制等各部门在各方面的应用,促进了我国计算机网的建设。美国早在1959年就开放了数据电话业务(Data phone);在1960年就开通了600bps和1200bps的数率传输业务。从70年代起,贝尔系统在公用电话交换网上的传输速率已达到了4800bps的水平。我国自打倒“四人帮”后。

Decay of Solutions to a Linear Viscous Asymptotic Model for Water Waves

The authors discuss a linear viscous asymptotic model for water waves and the decay rate of solutions towards the equilibrium.