无线直放机EMC设计基本要点

介绍了在无线直放机的设计和工艺制造过程中,针对EMC中的屏蔽、滤波、接地三大要素,所采取的一些基本措施;简要介绍了在EMC中常见的电源线干扰类型和电源线滤波器原理.     

装备制造业复杂产品研发的关键因素分析

装备制造业对国家经济的作用日益增强,而研发能力弱是制约发展的瓶颈.产品的跨学科知识集成、跨企业组织管理、用户定制、特殊的研发流程等特性增加了研发管理的困难.影响研发的关键因素包括：战略管理能力、资源能力、组织能力、项目管理能力和政府支持,通过对关键因素进行研究来提高企业研发能力并促进行业的发展.     

混沌频率调制技术在移相全桥变换器抑制EMI的应用

由于混沌信号的连续频谱的特性,可将其用于开关电源消除开关信号谐波的尖峰,从而抑制EMI。本文提出一种将混沌调制技术应用于移相全桥变换器的方法,该方法利用蔡氏电路设计了混沌信号电路,通过产生的混沌信号驱动开关电源PWM芯片的振荡器,实现开关频率的调制,使原本离散的开关信号频谱拓展到一定的频率范围。仿真结果表明该方法在确保系统稳定的基础上,能实现EMI的抑制。     

Critical perspectives on testing teaching: reframing teacher education for English medium instruction

The investigation reported here provides a basis for considering the role of corrective and transformative critiques in producing knowledge through testing teaching for reframing teacher education in response to, and as an expression of, the globalisation of English. This knowledge-producing approach to critique begins with a literature review of prior testing models of content and language integrated learning through English medium instruction (EMI) programmes. Delphi procedures were employed with a panel of 30 experts from three focus groups, namely teachers, testing experts, and teacher evaluation administrators. A comparison of relative importance of the indicators generated through this study via the analytic hierarchy process yielded practical implications for reframing the internationalisation of education using EMI. The analysis of interviews with teachers was used to critically rework or otherwise correct the testing model. Through adopting the practice of critique as a knowledge-producing venture, this study offers a model of EMI testing that can contribute to improvements in the organisation of professional learning and change, as well as certification procedures.     

一种能有效抗电网干扰的噪声滤波器

介绍了一种有效的噪声滤波器。以分析噪声的传播方式、结合滤波器所需对应的开关电源工作频率为基础来设计滤波器,无需复杂的计算,对不同工作频率的开关电源有较强的针对性。     

规模扩张的背后——分层的高等教育和断裂的社会

在高等教育分层理论和EMI假设的基础上,文章着重考察了高教规模扩张以后教育机会的阶层分布。认为当竞争从普遍入学转移到追求卓越之后,质的差异性将取代量的不均等而左右教育公平的实现。高教分层与社会分层相符应,复制并再生产了现存的社会关系,进而导致断裂社会的形成。