It introduces the definition of CBD and generalizes the basic characters of it,represents the develop history and present situation of internal CBD,discusses the main function of CBD and the mistake existing in the construction of internal CBD,and puts forward the future direction of the construction of internal CBD,to accelerate the construction of CBD of our nation.

The paper expounds the conference audio and video system of emergency command center from the constitution, the main function and design of the system.

It includes four parts such as its definition, types, motivations and main functions.

The paper selects the reasonable ratio of fiber concrete and tests the main performance parameters.

The author analyzes the FRP material and its product forms,provides main performance index of some kinds of fibers,further discusses the application of FRP on bridge,provides the existing problems of FRP composite material in Chinese large scale development,points out that the application of FRP composite material on bridge will be more widely.

This paper introduces a new type of computer technique based industrial controlling unit that can make the procedure control of make the mac hine operate through programming, and discusses on the design of the experimenta l table of the programmable logic controller (PLC) from aspects of the design sc heme, main functions, and program operation, etc.

Through a multidimensional analysis of code-switching in China,the author discusses its main functions.

It has three main functions: realization, method and construction.

Expounds how to materialize the major functions of jacquard CAD software on Windows 98 platform by analyzing the subfunctions under the major CAD functions.