EMC中的接地技术及地线中的干扰

讨论了接地的几种方式,探讨了地线中带来的电磁干扰,介绍了抑制和消除电磁干扰的途径和方法.     

接地技术的若干问题探讨

接地技术是电力电子设备电磁兼容技术重要内容之一，本文从接地种类和目的、接地方式等方面对接地技术进行了详细介绍。     

地线的干扰与抑制

地线的连接在高速电路板的设计中是必须要涉及到的环节,而由于地线阻抗的存在,必然会对电路的性能产生一定的负面影响。主要介绍在电路板制作中产生地线干扰的原因,并提出抑制地线干扰的方法。     

电磁干扰及抑制与防护

从电磁干扰的危害效应入手,着重介绍电磁干扰的抑制与防护措施之一即接地技术,具体分析了电路、布局与接地的方法,并综述了电磁兼容性技术所面临的问题.     

智能建筑电气接地技术探析

论述了智能建筑供配电系统接地方式的选择,分析了智能建筑采取共用接地系统的必要性,对电缆屏蔽层的接地方式及其抑制电磁干扰的作用进行了阐述,并给出接地设计要点。     

电磁兼容设计中的接地技术

讨论了电磁兼容的地线干扰产生的原理及抑制地线干扰的各种接地技术。     

智能建筑电气接地技术探析

论述了智能建筑供配电系统接地方式的选择,分析了智能建筑采取共用接地系统的必要性,对电缆屏蔽层的接地方式及其抑制电磁干扰的作用进行了阐述,并给出接地设计要点。     

电子设备的地环路干扰及抑制措施

讨论了电子设备中地环路干扰的形成,探讨了地环路干扰的产生原因,介绍了几种抑制和消除地环路干扰的途径和方法.     

多媒体系统集成中的接地技术

接地技术直接影响到多媒体应用环境的视听效果与安全.针对多媒体系统集成中遇到的一些问题,根据在实际应用工程中的体会,介绍了多种行之有效的接地技术,并阐述了其工作原理、实现方式和特点.     

Single-phase earth fault current distribution between optical fiber composite overhead ground wire and ordinary ground wire in transmission system

It is important for the safety of transmission system to accurately calculate single-phase earth fault current distribution. Features of double sided elimination method were illustrated. Quantitative calculation of single-phase earth fault current distribution and case verification were accomplished by using the loop method. Influences of some factors, such as single-phase earth fault location and ground resistance of poles, on short-circuit current distribution were discussed. Results show that: 1) results of the loop method conform to those of double sided elimination method; 2) the fault location hardly influences macro-distribution of short-circuit current. However, current near fault location is evidently influenced; and 3) the short-circuit current distribution is not so sensitive to the ground resistance of poles.     

CCD器件与光学仪器配接的物像关系及相关技术

该文介绍了如何在几种典型光学实验仪器中,将光学像作为CCD器件的输入,通过监视器或计算机实时观察调节现象,同时给出了CCD器件与光学仪器配接时的物像公式.此举不但解决了实验教学过程中仪器调节与现象不能同步展示给学生的矛盾,同时也为现有光学实验仪器的升级换代起到示范作用.     

The history curriculum and its personal connection to students from minority ethnic backgrounds

Whereas history is seen by some as crucial in developing a sense of identity and fostering social cohesion, it is however, often based around narrowly nationalistic views of the past, and yet little is known about how students relate to the past they are taught. Thus, this paper focuses on the history curriculum and the ways in which students aged 12–14, from different ethnic backgrounds, relate to it. Moreover, the small-scale study which enabled this paper, focused, in particular, on whether students enjoyed and valued history and whether they felt any sense of personal connection to the topics studied. Drawing on survey data collected from 102 students and focus group discussions with 42 students, from two high schools, the findings indicate that although many students enjoy history, they fail to fully understand its value. Additionally most students, especially those from minority ethnic backgrounds, feel a lack of personal connection to the past, as they do not see themselves in the history they are taught.     

Voices from the ground: The emotional labour of English teachers' work

This paper examines the complex emotional work of English language teaching in Singapore secondary schools. Findings revealed the emotional burdens, tensions, and challenges associated with the teaching of English, largely attributed to the subject's value-laden content, the stresses of grading student essays, the performance pressures of high-stakes testing, and the need for culturally responsive pedagogies. Further studies of teachers' lived experiences in relation to their disciplinary domains can offer teacher educators and policymakers insights into the ways in which curriculum and policy impact on, and are impacted by, the emotional realities of teachers' work.     

Science and thinking: The write connection

The effective use of writing in science instruction may open the way for students to grow in their ability to exercise higher order thinking skills (Bland & Koppel, 1988). Scinto (1986) makes a compelling case for writing as a means of stimulating thinking when he states: The production of written text demands more elaborate strategies of preplanning. Written language demands the conscious organization of ensembles of propositions to achieve its end. The need to manipulate linguistic means in such a conscious and deliberate fashion entails a level of linguistic self-reflection not called forth in oral discourse (p. 101).     

会展英语教学中课程设置与实际工作项目的衔接

本文以会展英语在实际工作项目中的应用为出发点,结合教学实际,对增强会展英语教学中课程设置与实际工作项目的衔接措施进行着重分析。     

政治关联与企业行为的研究综述

近年来,政治关联对企业行为所产生的影响成为国内外学者关注的热点.在分析政治关联的界定及影响因素基础上,梳理政治关联对企业行为影响的国内外研究成果,以期为该领域的深入研究提供理论铺垫.