网络综合布线介质的主流--光纤

通过对光纤和铜缆在网络应用中的特性分析，光缆和铜缆的优缺点比较，认为光缆有着很多铜缆不可相比的优势，如抗电磁干扰、传输距离大、带宽扩充性好等，今后随着网络通信对带宽要求的不断提高和光纤技术的不断发展，光纤必将取代铜缆而成为网络综合布线的主流介质。     

Selection of minimal tripping times for distance protection using fault trees with time dependencies

Correct coordination between protection relays is an essential requirement to maintain stability and integrity of electrical power systems. Time settings of protection relays have to be adapted to time characteristics of electrical power systems and time settings of other protections. In the paper, fault trees with time dependencies (FTTD) are used for selecting time delay settings of remote back-up distance protections. In FTTD, events and gates are characterized by time parameters, which are derived from time characteristics of protection devices and the inherent delays of protection equipment. Two case studies are presented. First, the coordination of protections for the simple transmission line composed of two identical sections is studied. Next, the transmission line that contains two sections of different lengths and transformer between them is analyzed. In both cases, formulae for time delays of protections are derived. According to calculations executed for the first case, our method gives time delays that often are significantly smaller than values suggested by generally recommended and accepted rules.     

一种光纤到桌面系统的实现

介绍一种光纤到桌面系统的组成，组网方式、主要技术指标，并将其与普通双铰线局域网进行了各方面性能的比较。     

基于数据通信与电话通信相结合的以太网光纤收发器的研究与应用

本文在化工设备泄漏检测、预警与应用救援系统研究中提出了一种新型以太网光纤收发器,采用数据通信与电话通信相结合的方式,通过以太网光端机模块通过总线方式与CPLD模块相连接,CPLD模块通过专用接口与电话处理模块相连接,电话处理模块连接到壳体上的电话接口上.避免了通信资源的浪费、节约了通信成本,具有使用及维修方便的特点,可广泛应用于一些企事业单位中的专用通信网中.