氧化锌压敏电阻静电放电防护性能的测试

研究常用静电放电防护器件氧化锌压敏电阻的静电放电防护性能,设计了一套静电放电防护器性能测试方法,搭建相关测试平台。研究了该保护器件及其组合网络对静电放电脉冲的响应规律及特点,分析了动态导通电阻、箝位电压、响应峰值电流等参数与其静电放电防护能力的关系,并给出了最佳防护方案。该研究为电路设计时选取氧化锌压敏电阻作为静电放电防护器件提供了参考。     

双极型晶体管EM大信号模型参数提取方法探讨

集成电路设计过程中离不开计算机模拟,模拟的精确度不仅与器件模型本身有关,还与给定的器件模型参数值是否正确密切有关,所以准确地提取器件的模型参数显得至关重要。双极型晶体管是集成电路中重要组成单元,为提高学生对集成电路设计中对晶体管单元的参数含义的全面深刻认识,在介绍了双极型晶体管各种模型参数的基础上,分析了三极管EM模型参数的相关公式;并讨论了其模型参数提取的简单易行的方法;最后介绍了参数提取的实验设备和仪器、实验方法和实验手段。该实验方法可以帮助学生掌握双极型晶体管模型参数的提取,同时可以加深学生对双极型晶体管模型参数物理意义的理解。     

关于三极管放大区和饱和区的工程划分

通过短路埃伯尔斯-莫尔模型对双极型晶体管的放大工作状态和饱和工作状态进行了分析,按照所分析的结论,通过实例说明在发射结正偏、集电结也正偏(但偏置电压较小)时,双极型晶体管仍处于放大状态。     

双极性晶体管等效电路的教学实践

为分析双极性晶体管放大电路而引入的众多双极性晶体管等效模型加重了初学者负担.本文介绍了一种从双极性晶体管物理结构出发推导出高频低频等效电路以简化分析手段、突出教学目的的教学尝试,同时利用仿真软件的辅助分析加深初学者对工程近似概念的理解.     

一种新型优化热载流子退化效应的SOI-LIGBT(英文)

提出了一种新型绝缘体上硅横向绝缘栅双极型晶体管(SOI-LIGBT),该晶体管在沟道下方的P型体区旁增加了一个特殊的低掺杂P型阱区,在不增加额外工艺的基础上减小了器件线性区电流的退化.分析了低掺杂P阱的宽度和深度对SOI-LIGBT器件热载流子可靠性的影响.通过增加低掺杂P型阱区的宽度,可以减小器件的纵向电场峰值和碰撞电离峰值,从而优化器件的热载流子效应.另外,增加低掺杂P型阱区的深度,也会减小器件内部的碰撞电离率,从而减弱器件的热载流子退化.结合低掺杂P型阱区的作用和工艺窗口大小的影响,确定低掺杂P型阱区的宽度和深度都为2μm.     

基于Mathematica的半导体物理与器件实验仿真平台开发

利用Mathematica软件开发了半导体物理与器件实验仿真平台。该实验仿真平台设置了10个仿真实验项目。以PN结能带图、双极结型晶体管输出特性、理想MOS电容C-V特性等3个仿真项目为例,说明模块的界面设计、仿真的理论依据和实现的具体功能。该仿真平台具有交互性强、图形动态连续输出和特征参数跟踪显示等特点,可作为课堂理论教学的有效补充,并且解决了实验教学仪器设备不足的问题。     

MOS-FET共源极放大器频率特性的分析

本文就MOS－FET的高频等效模型对MOS－FET共源极放大器的频率计算特性进行了系统分析,并与双极型晶体管放大器相比较,得出了几点重要结论：MOS管有很高的输入电阻．因此在相同的输人电容影响下,很高的输入电阻将影响其高频响应变差;MOS管用作放大时不能象双极管那样大的电压放大倍数;MOS冒产生的电噪声比双极型管要小,故适应于低噪声放大器的输入极。     

双极型伴随运算放大器的特性及应用研究

应用伴随运算放大器将通用电压模式的电压运放电路转换为电流模式电路，提出一种双极型晶体管伴随运放电路，分析其开环特性，并利用其组成闭环电流放大器和五阶低通滤波器。     

高温硅功率器件所用硅单晶电阻率的选取

在进行高温硅功率器件设计时，为保证器件的温度特性，必须正确、恰当地选取硅单晶电阻率，理论分析与实验相结合，可根据硅功率器件额定结温确定硅单晶电阻率的上限值，根据硅功率器件反向击穿电压确定硅单晶电阻率的下限值，在此基础上，设计制造了满足坦克用的高温硅功率器件，额定结温达190℃。     

雪崩能量在功率场效应晶体管封装测试中的作用

随着大功率场效应晶体管(Power MOSFET)的应用越来越广泛,由于场效应管失效引起的整机失效的比例也在逐渐上升.这这些失效中,很大一部分是由于器件无法承受瞬间高电压脉冲,致使器件管芯烧毁失效.即器件位通过雪崩能量测试或者说器件未通过合适的雪崩能量测试.本文就雪崩击穿的机理、雪崩能量测试的原理、雪崩失效的分析进行一些探讨,从而给出减小雪崩失效的方法.     

Education for sustainable development and the secondary curriculum in English schools: rhetoric or reality?

Can education for sustainable development (ESD) policies help to create a more sustainable society? In the article I argue that contemporary secondary school curriculum policies relating to ESD are rhetorical devices that will achieve little towards resolving global problems. I suggest that the conceptualization of SD is itself fundamentally flawed and inevitably restricts the scope of possible policy solutions. I analyse three ESD curriculum policy texts to reveal their concealments, silences and blocks to enquiry, demonstrating how their rhetorical forms make them readily assimilable into dominant economic discourse. I then introduce a recent UK Government Report explaining the failure in implementing ESD policies in the school curriculum and I expose how this analysis is a further demonstration of the problems in the prevailing policy perspective. In conclusion, I propose a new direction for progress in curriculum policy regarding sustainability.     

Semiconductors

The principal aim of this paper is to present the concepts associated with the electrical properties of semiconductors. Simplified ways of envisioning holes, electrons, and diode and transistor action are presented. Intrinsic or pure semiconductor material is discussed first, followed by discussions of n- and p-type material, p-n junction diodes, photodiodes, and transistors. The paper is aimed at educators who are not directly involved with semiconductor devices.     

可持续发展教育的有效推进——中国可持续发展教育项目特色评述

教育是可持续发展变革的重要手段。中国可持续发展教育项目的特色主要表现为:在国际视野下结合中国实际进行可持续发展教育的理论构建,是可持续发展教育扎根于中国的奠基石;整体进行可持续发展教育课程设计,是可持续发展教育理念真正落到学校教育改革实际的基本环节;定期组织国家讲习班和国际论坛等多种师资培训活动,是传播可持续发展教育理念与成功经验的必要平台。在科学发展观的指导下,以进一步落实《联合国可持续发展教育十年(2005-2014)国际实施计划》为契机,作为可持续发展教育的"旗舰"项目,中国可持续发展教育项目应当适应学校发展的实际需要,深入开展可持续发展教育课题研究;建立学校、政府、社会、企业等共同参与、利益共享的同盟关系,全方位扩展可持续发展教育的合作空间。     

Low-leakage diode-triggered silicon controlled rectifier for electrostatic discharge protection in 0.18-μm CMOS process

A diode-triggered silicon controlled rectifier （DTSCR） is being developed as an electrostatic discharge （ESD） protection device for low voltage applications. However, DTSCR leaks high current during normal operation due to the Darlington effect of the triggering-assist diode string. In this study, two types of diode string triggered SCRs are designed for low leakage consideration; the modified diode string and composite polysilicon diode string triggered SCRs （MDTSCR ＆ PDTSCR）. Compared with the conventional DTSCR （CDTSCR）, the MDTSCR has a much lower substrate leakage current with a relatively large silicon cost, and the PDTSCR has a much lower substrate leakage current with similar area and shows good leakage performance at a high temperature. Other DTSCR ESD properties are also investigated, especially regarding their layout, triggering voltage and failure current.     

Chemistry Teaching for the Future: A model for secondary chemistry education for sustainable development

For more than 40 years, the international community has acknowledged the role education might play in environmental awareness and conservation. The last major initiative came when the United Nations General Assembly proclaimed a Decade of Education for Sustainable Development (2005–2014). In the final year of the decade, teachers still struggle to realise education for sustainable development (ESD). One of the challenges teachers face with respect to ESD is the inclusion of even more content into an already overloaded curriculum. In response, it has been suggested that ESD should be introduced as an integrated perspective across the content of all existing subjects. This paper offers a model for how ESD can be realised in chemistry education. The model has been developed to support chemistry teachers in their educational planning and consists of 5 categories: chemical content knowledge, chemistry in context, the distinctiveness and methodological character of chemistry, ESD competences and lived ESD. The ESD model is illustrated through 5 ellipses, visualising the hierarchy of the categories, as they exist in different levels. All 5 ESD categories need to be considered in a holistic ESD approach.     

论环境教育与可持续发展教育

环境教育和可持续发展教育究竟有怎样的关系?国内外学者看法各异。归纳起来,主要有五种:第一,环境教育与可持续发展教育是等同的;第二,可持续发展教育是环境教育的一部分;第三,环境教育是可持续发展教育的一部分;第四,可持续发展教育与环境教育互不包含,但有共同的部分;第五,可持续发展教育是环境教育发展过程中的一个高级阶段。根据相关文献分析,我们认为,环境教育是可持续发展教育的一部分,两者关系是互动的,环境教育需要面向可持续发展重新定向,可持续发展教育有着环境教育无法实现的功能。     

TFT_LCD驱动芯片输入输出引脚静电放电保护电路设计

描述了TFT_LCD驱动芯片静电放电（ESD）保护电路的布局,重点分析和设计了TFT_LCD驱动芯片输入和输出引脚的ESD保护电路,ESD保护电路布局上,采用2排ESD电路错开呈“品字形”排列,使ESD电流均匀流通,在输入引脚保护电路中,采用2级保护结构,主电路吸收ESD大电流,次级电路吸收剩余的ESD电荷,栅极耦合技术进一步保证电路各Fingers均匀触发。输出引脚ESD保护电路基本电路采用CMOS结构,采用NP点分离驱动技术解决PMOS和NMOS可能同时出现瞬间导通的问题。双向输入输出引脚的ESD保护电路包含了输入和输出引脚ESD保护电路的结构。     

Embedding Education for Sustainable Development in higher education: A case study examining common challenges and opportunities for undergraduate programmes

This paper explores the perceptions of academics and students towards embedding Education for Sustainable Development (ESD) into undergraduate degree programmes in the School for Earth, Ocean and Environmental Science (SEOES) at the University of Plymouth. The main purpose of the research was to identify current ESD related teaching and learning in a science-based undergraduate programme and the opportunities for, and barriers to, further extensions of ESD. The results indicate that there is general support for the embedding of ESD in the curriculum, but there is considerable uncertainty expressed by lecturers concerning how this can best be done. There is a general concern that additional embedding into the degree programme might lead to reductions in the amount of core subject matter being taught. The programme and ESD agendas are to an extent seen by lecturers as conflicting. ESD is viewed mainly in terms of curriculum content as opposed to the pedagogy employed.     

The actual use of embedded support devices in self‐study materials by students in a distance education setting

At the Dutch Open university much time is invested in the didactical elaboration of written study materials by the embedding of a large set of ‘embedded support devices’ (objectives, advance organisers, questions, tests, etc.). Is this high investment in the design of written study materials for use in the distance education setting worth the effort? To answer this question, we focused in this research on the actual use of these embedded support devices (ESD) by Open university students. After elaborating a theoretical model that was helpful to derive hypothetical functions and effects of a large set of ESD, quantitative and qualitative hypotheses were put forward in relation to the actual use of a subset of ESD that was implemented in a law course. The research set‐up was based on an in‐depth analysis of responses to structured interviews. Analysis of the results indicate that students make large use of ESD; nearly all ESD are used by more than 60% of the students. Furthermore, students make deep level use of the ESD. Moreover, interrelations could be detected between general student characteristics and deep level use of ESD. Women seem to be more likely to use planning ESD, orientating ESD and processing ESD at a deep level. Students with higher prior education levels seem to use ESD at deep level to a greater extent. Students with less prior knowledge of governmental law and students using study guidance use testing ESD more at a deep level.

No interrelations were detected between cognitive student characteristics and the use of ESD.

To get a better view of the ‘type’ of students using ESD, the interrelations between general student characteristics have been analysed. Especially higher educated (and intrinsic motivated) female students with a lot of study experience and less prior knowledge make deep level use of ESD. When linking the use of ESD to study success, it could be stated that students using ESD at a deep level are not only more likely to have a higher score on the examination, they also need fewer examination attempts. Comparing theoretical and spontaneously mentioned functions and effects of ESD revealed that students indicate functions that are not theoretically expected. Students seem to ascribe their own functions and effects to ESD.

The main conclusion of this research is that the high investment in the design of written study materials is worth the effort; but that it is important to take account of student characteristics when implementing ESD in course materials. It can, for instance, be argued it is desirable to incorporate into the materials ‘training’ about the use of the ESD. Moreover, these results link up with the growing tendency to develop more flexible Ou‐courses that are adaptable to individual student needs. The latter implies that the production of written versions of the study materials is to be redirected towards the development of automated interactive learning environments.     

Leading sustainable schools: exploring the role of primary school principals

The purpose of the paper is to identify the kinds of leadership that are likely to support implementing and sustaining education for sustainable development (ESD) effectively in a primary school. The paper identifies links between ESD and principal leadership literature and constructs a conceptual model of the leadership practices needed for reorienting a school to ESD/education for sustainability. Aspects of the model are explored through Cypriot principals' views on leadership and reported leadership practices. Data were obtained by a nationally administered questionnaire and semi-structured interviews. Outcomes indicated some enabling factors for ESD implementation such as encouraging teachers to engage in ESD programmes, collaborate with others and other ways of support which nevertheless reflect what is generally expected of school administrators without seeking deep change. Constraining factors included principals' reported lack of confidence in administrative skills for sustainable schools, limited willingness to challenge the status quo, limited engagement in actions important for supporting ESD activities and features of the national educational policy. Constraining factors pointed towards principals' limited commitment to ESD. The practical significance of the findings is that they identify specific areas of needed professional development for principals such as empowering staff, encouraging critique of current approaches and exploring alternative possibilities for curriculum, pedagogy and policy.