All the problems which the thesis will solve and the basic concepts are listed in order to help readers to understand . the performance of ethernet applied to automatic control is the focus discussed by engineers and researchers . through simulations , the comparison of the performances and characteristics of ethernet controlnet and devicenet are given 通过比较以太网( ethernet )与控制网( controlnet ) 、设备网( devicenet )在不同情况下的性能指标，给出模拟仿真结果，得出各种网络的优缺点。
On database and conect with the current condition on the examination theory , wuhan chemical college computer test system aim at the characteristic of the basic computer , use this kind of manner to realize test without paper , in wuhan chemical college we design the the whict computer aided test , use the diffent mode in the different condition . . the clasical test is always used in the final test in term , give a certain point to students according with the present teaching system . the comupter adaptived test is used in trainingto find students ' shortage . the whict computer test can accord to the teaching evaluation system to analyse students ' capacity and papers ' quality for improving our teaching molar 以考试理论为基础并结合实际应用，武汉化工学院考试系统针对计算机基础课特点，采用计算机辅亡玉八硕士学住论文wniaster ’ stifesis助考试方式，实现学科无纸化考试，设计在不同情况下采用不同模式，传统考试应用于学科的考试测验，可以给学生打分，符合现行教学制度，自适应考试用于学生练习，找到自己的不足，考试系统还能够按照教学评估体系的要求对学生能力和试卷质量进行分析，从而达到对教学质量的提局。
