李雅普诺夫指数降低开关模式电源电磁干扰水平研究

研究混沌信号正的李雅普诺夫指数对降低开关模式电源电磁干扰水平效果的影响．仿真结果表明：混沌信号正的李雅普诺夫指数越大，正李雅普诺夫指数个数越多，降低开关模式电源电磁干扰水平越好．     

灯箱的高频AC/DC变换器设计

针对现有灯箱组合使用一般的日光灯镇流器的弊端,本文开发研制出一种高频AC/DC变换器,其具有EMI干扰小、功率因数高等优点。     

牛津大学EMI Co-Teaching教学方法的研究与实践

在高等教育国际化发展如火如荼的今天,如何更好地开展英文媒介教学活动是高等教育工作者必须思考的重要问题.本文以牛津大学EMI(English Medium Instruction:英文媒介教学)中的Co-Teaching教学方法为研究对象,探讨如何把不同专业的教学内容通过多种教学方式协作起来,促进学生的交叉学科学习和全面发展,激发学生的创新思维,以达到提高教学效果和培养复合型人才的目的.     

转移阻抗法测试EMI衬垫屏蔽效能

本文介绍了用屏蔽室测量法、模搅拌小室(MSC)方法、ASTM方法、直流电阻法和转移阻抗法测试EMI衬垫的屏蔽性能。并且根据穿透EMI衬垫的能量与衬垫的转移阻抗成反比的原理，着重探讨了用转移阻抗法进行屏蔽效能测试的原理、测试系统结构和计算方法。     

Korean Science and Engineering Students’ Perceptions of English-Medium Instruction and Korean-Medium Instruction

The purpose of this study was to examine how Korean science and engineering students view English-medium instruction (EMI) and Korean-medium instruction (KMI). The participants were 174 undergraduate students enrolled in EMI and KMI classes offered by the same instructor at a Korean science and engineering school. Interviews and questionnaire surveys were conducted, and students’ course evaluations, English scores and course grades were compared. The results of a campus-wide undergraduate student survey on EMI were also analyzed. The findings of the study show that the KMI-class students demonstrated higher levels of satisfaction and better performance in their classes than the EMI-class students did. Only 22% of the students in both classes found EMI classes helpful for improving their English ability. Nevertheless, the majority of the students supported the school’s maintenance of an EMI policy. In the conclusion, the paradoxical attitude of the students and the implications of the study are discussed.     

电磁兼容技术在自动化专业实验室中的应用

电磁兼容作为一门边缘学科,其应用越来越广泛;分析了自动化专业实验室中主要电磁干扰,并结合电磁干扰产生原因的具体情况,探讨了采取相应抑制措施。     

A novel topology for ripple-free inputting current techniques

A novel topology for ripple-free input current circuit is put forward in the paper. Compared to traditional EMI (electromagnetic interference) filter consisting of choke and capacitor, the ripple-free topology can reduce the converter's ripple current with the use of smaller component. The new ripple-free topology proposed in this paper does not need elaborate adjustment of the coupling coefficient as required by conventional ripple-free techniques, and is ripple voltage cancellation or isolation mode, which can attenuate the ripple further if the line impedance is considered. The theoretical prediction is confirmed by experimental results. Project supported by the Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry     

Simulation on Foft—Switching PWM Converter with High Power Factor

A new PWM converter based on soft-switching is introduced.The converter uses a minimum number of devices,and requires less switching operations than conventional techniques,Switching is realized solely in a ZVS)zero voltage switching)mode,therefore the loss is reduced and EMI(electromagnetic interference)is suppressed.The paper analyzes the operation of ZVS,and discusses the methods for maintaining a unit power factor and constant DC voltage.Changing the modulation index M and the phase angle θ keeps the input current in phase with the voltage.It also keeps the current sinusoidal,and ensures a constant output voltage.     

使用混沌调制方法实现交流电机电磁干扰抑制

Instead of avoiding occurrence of chaos in motor drives,chaos is positively utilized in this paper.A new chaotic pulse width modulation (PWM) scheme is proposed and implemented for AC motors,which functions to significantly suppress harmonic peaks and hence acoustic noise.The key is to employ the Chua's circuit for generating a desired chaotic sequence.By using a practical induction motor,computer simulation and experimental results verify that the chaotic PWM has advantages of harmonic peak suppression and simple hardware implementation over the conventional PWM and random PWM.     

宽频带EMI滤波器的设计及其插入损耗分析

介绍了一种简便的宽频带EMI滤波器的设计方法,给出其插入损耗的计算式,并通过仿真试验验证了这种设计方法的有效性。