LPS, which is used as feed stock to synthesize PCS under normal pressure at high temperature, is composed of the backbone structure of polysilane ( Si-Si) and PCS ( Si-C). Active group Si-H in the chain can easily react with double bonds by hydrosilication.

Some important IP-based multicast protocols are introduced in this paper. Some problems existing Internet multicast backbone network are pointed out, and resolving method are proposed.

本文分析比较了几个常见IP组播协议原理、方法与特点，指出了当前Internet组播协议存在的问题，并提出相应的解决方法建议。

National natural science foundation of China network ( NSFCNET) is the first high-speed computer network test bed providing native multicast service across its backbone.

中国高速互联研究试验网是我国第一个全网支持非隧道组播协议的下一代高速互联网试验床。

Scalable Application Layer Multicast Based on Backbone Network

基于主干网信息可扩展的应用层组播

STD was a rock band made up of computer technologists from Digital Equipment Corp., Xerox, Apple, and Sun, giving them inside knowledge of a technology called Multicast Backbone ( M-bone).

STD是一个由来自迪吉多电脑公司的几位计算机技术专家组成的摇滚乐队。施乐、苹果以及太阳公司给他们提供了内部知识，M-bone多址传播主干网。

The clip shows him climbing over the glass backboard and standing on the back of the rim.

视频中，只见他翻过玻璃篮板，站在篮筐的边缘上。

Results: in terms of the incidence of postoperative headache, lumbago and backache, and local skin compressed, patients in test group were lower than that in control group ( P < 0.01).

结果：观察组病人术后头痛、腰背痛及皮肤受压的发生率低于对照组（P<0.01）。

Discussion on Improving Adaptability of Back-Up Protection of 110 kV Transmission Line

提高110kV线路后备保护适应能力的探讨

Study of back-up protection configuration schemes in power market environment

市场环境下后备保护配置方法的选择

It is described that the sensitivity of impedance back up protection for transformer wind short circuit is very low.

介绍了后备阻抗保护对变压器绕组短路灵敏度很低。

Research of the cooperation of middle-low voltage back up protection of transformer and outlet protection setting

变压器中低压后备保护与出线保护整定配合的研究

Application of comprehensive back up protection device of hoist

浅谈提升机综合后备保护装置

Some Problems Needing Consideration in the Design of the Interphase Back up Protection of the Microcomputer Transformer

微机变压器相间后备保护设计需考虑的几个问题

This paper analyzes the back up protection of varistors.

本文就目前所存在的各种压敏电阻后备保护技术进行分析论述。

Improvement of Operating Technology of Bearings for Back-up Rolls on Medium Plate Mill

中板轧机支承辊轴承使用技术的改进

The paper introduces the new processing and technique such as embedded back-up plate, wholly craning and installing the guide pulley, etc. which are used to install hoist, which can not only improve installing quality and simplify installing procedure, but also can raise the working efficiency.

介绍了提升机安装中采用预埋垫板、导向轮整体吊装等新工艺、新技术，不但提高了安装质量，简化了安装工序，而且还提高了施工效率。

He said he was lucky the airport had a back-up system of its own generators& otherwise he would have to try to land in total darkness.

他说，幸运的是，机场自己有后备的发电设备。否则，他得设法在黑暗里降落。

BlackBerry users cursed their devices, which stopped working because of problems at servers for which a back-up system failed to work.

黑莓用户最近对其运营商骂声不断，这主要是因为手机服务器的备份系统不工作而使手机无法正常工作。

If system breakdowns or failures would result in the permanent loss of records, a back-up system should be provided.

如果计算机的故障或失效会导致记录的永久丢失，则应当提供备份系统。

Favourable social and technical environment and social back-up system are the social basis for the normal development of productive forces of modern society.

良好的社会技术环境和社会支持体系，是现代生产力正常发展的社会基础。

To establish a safe back-up system of double service unit for hospital

建设安全可靠的医院双服务器备份系统