基于西门子变频器的变频调速控制技术在矿井提升机的应用

鉴于煤矿目前的矿井提升机普遍使用交流绕线式电机转子串电阻调速,提升机在减速和爬行阶段,负载变化时,实现恒减速难度大,经常会造成过放或过卷,转子串电阻能耗大,电路复杂。针对上述问题,设计了西门子变频器在提升机调速系统中的应用。解决了提升机恒加速和恒减速控制,避免了过卷和过放,控制电路简单,具有十分广阔的适用性。     

流程图法在城轨车辆车门系统教学中的研究与应用

传统教学法经常导致学生学习起来感觉枯燥无趣,捕捉不到重难点等问题,现提出一种流程图教学法,并将其融入到专业课程教学中。该教学法能够简单、直观地展示出城轨车辆车门系统中知识点的逻辑性,重难点,加深学生对知识的理解。教学实践表明,流程图法使复杂的知识重新构建,帮助学生理解并掌握知识精髓。流程图法在城轨车辆车门系统中的应用,教学效果良好,对类似学科具有一定的参考价值。     

Triggering Discussions on Ethics and Values: Cases and Innovative Case Variations

When designing instructional activities focused on issues of ethics and values, teachers commonly search for cases that generate effective discussions. Such cases often are short, open-ended, realistic, incomplete, and impactful. The last quality may result from visual images and emotional content. Some alternatives to simple individual reading of a case, which is a traditional opening approach, help increase the case's impact severalfold—for example, video and slide-tape versions. Other alternatives offer ease of preparation and presentation—for example, staged readings. Seventeen innovative variations are offered in this paper as options that can match particular circumstances of the instructional venue.     

Reading practice in Irish primary classrooms: too simple a view of reading?

This article investigates issues surrounding the adoption of the ‘simple view’ of reading. While this theory of the reading process has recently been espoused as the official view of early reading instruction in England, a recent Irish study, discussed in this article, indicated that this view of reading is also widespread among Irish teachers. This article argues that a less simple view of reading recognising the importance of cognitive flexibility, metacognition and explicit comprehension strategy instruction in reading needs to be promoted among all educators. A lack of emphasis on such explicit reading comprehension instruction has been found to be a common thread in research conducted in the United States, in England and in Ireland and is often linked to reading underachievement. Hence, the authors conclude that the implementation of a more holistic and inclusive ‘balanced’ model of reading development is immediately imperative in reading classrooms, both in Ireland and internationally.     

Flexible learning in teacher education: myths,muddles and models

While there has been widespread take‐up of the concept ‘flexible learning’ within various educational environments—and equally frequent references to the flexible ‘natures’ of the computer and communication technologies that often underpin flexible learning initiatives—the relationship between technologies and flexibility is not a simple one. In this paper we examine some of the more persistent myths about technologies that are intertwined with discourses of flexibility. We highlight some of the more common ‘muddles’ that these myths can lead us in to and argue that the ‘mess’ that so often results from well‐intentioned moves to ‘be more flexible’ is largely a result of the ways that CCTs, or indeed any new educational technology or strategy, is theorized. Drawing on a recent study of online teaching and learning in higher education, we outline a new framework for examining these and related issues as they apply to teacher education.     

2010年台湾语文热点及特点分析

2010年台湾语文热点频出,从这些热点问题来看,民生性、差异性和弱势性话题容易成为语文热点。台湾语文热点常常与文化联系在一起,是台湾深耕本土意识、连接两岸关系和拓展国际空间的重要手段。     

物资采购合同签订时的法律规范

在物资采购签订买卖合同时，经常会碰到一些问题，如供货商的问题、代理人的问题、合同条款的问题和合同履行的问题等。忽视这些问题而签订的合同执行起来容易产生纠纷。本文以《合同法》为依据，针对高校在物资采购中买卖合同签订应注意的若干问题进行探讨。     

360° Feedback: Ready,Fire, Aim—Issues With Improper Implementation

This article looks at 360° feedback, as well as mistakes and misuses that are often made in its implementation and use. Too often individuals look for tools to give them facts to support predetermined opinions rather than gathering facts to support individuals in their growth and development process. By identifying these issues and addressing them up front, larger issues that can negatively affect the overall culture of an organization can be avoided.     

报纸媒体“读书”类专刊的价值取向

本文从三个方面探讨了报纸媒体“读书”类专刊的价值取向:其一,报纸媒体“读书”类专刊是沟通书与读者的有效桥梁,形成了“浅阅读文本”的“文本”价值追求其二,报纸媒体“读书”类专刊的价值定位在于思想性与新闻性并重;其三,报纸媒体“读书”类专刊的价值崇尚是提高自身文化品位,争取“文化吸引力”。     

完善我国彩礼返还法律规则的思考

我国司法解释设置的彩礼返还规则,在解决彩礼返还纠纷中发挥了重要作用。但现行彩礼返还规则过于简单,显得粗糙,在司法审判中出现很多问题,引发了许多争议;不同地区的法院,甚至是同一法院的法官对同一性质的案件往往达不成统一的认识,导致对同一性质的案件有着不同甚至截然相反的判决。鉴于彩礼返还在现实生活中引发大量的民事纠纷,以至引发刑事犯罪。对彩礼问题进行必要的分析,针对现实中出现的相关法律问题提出一些解决方案,作为立法建议,有助于统一认识,规范司法行为,减少社会矛盾,实现社会公平,促进社会和谐。     

Training Culturally Competent Social Workers

ABSTRACT

Many social work educators have expressed a commitment to including information aboutdiverse populations in their teaching yet this is often easier said than done. Limited class time is available to cover many important issues and in spite of the best of intentions, diversity issues often receive inadequate attention. In particular, content on Native American people is often left out of the social work curriculum. Specific recommendations are made about how social work educators can teach students to work effectively with Native people. Suggestions on what content should be taught, how it can be taught, and where it can be integrated into the social work curriculum are included.     

Multilevel covariance structure analysis of sibling antisocial behavior

Conventional covariance structure analysis, such as factor analysis, is often applied to data that are obtained in a hierarchical fashion, such as siblings observed within families. Multivariate modeling of such data, however, is most frequently done as if the data were obtained as a simple random sample from a single population. An alternative specification is presented that explicitly models the within‐level and between‐level covariance matrices in familial antisocial behavior. Sibling data from the National Youth Survey, a national probability sample of youth, were used to specify a multilevel covariance structure analysis of sibling antisocial behavior. Results demonstrate homogeneity in antisocial behavior within sibling clusters but heterogeneity across families. These analyses highlight potential pitfalls of ignoring issues of independence and demonstrate how conventional covariance structure software can be easily adapted to handle hierarchical models, providing a large set of new analysis possibilities for multilevel data.     

The Case of Turkish University Students and MOOCs

Though initially proposed as a means of overcoming common barriers to higher education, MOOCs often exacerbate the very issues of accessibility and exclusivity that they were designed to avoid. Students from developing countries in particular face considerable obstacles that hinder or outright prevent their enrollment in and completion of MOOCs. This study finds that, for these students, participation in MOOCs is often complicated by language barriers, limited technological resources, and prevailing Americentric or Eurocentric designs and mindsets, among other issues. These findings were determined and reinforced by a study of Turkish college students from a large state-sponsored metropolitan university, who indicated different levels of knowledge regarding MOOCs as well as various issues, concerns, and complaints. These issues of accessibility and exclusivity must be addressed before MOOCs will truly be able to democratize access to high-quality university-level education, and the best solutions are those that acknowledge the multicultural nature of their user communities.     

A multi-peer assessment platform for programming language learning: considering group non-consensus and personal radicalness

Multi-peer assessment has often been used by teachers to reduce personal bias and make the assessment more reliable. This study reviews the design and development of multi-peer assessment systems that detect and solve two common issues in such systems: non-consensus among group members and personal radicalness in some assessments. A multi-peer assessment model is proposed to address these issues. The model captures roles, activities, and data structures in a typical multi-peer assessment setting that can be generalized to other scenarios. We implemented the model in a multi-peer code review system and conducted several empirical experiments in programming language classes. The studies showed that the model can significantly improve student learning outcomes than in a single-peer assessment. Also, we used statistical measures to detect non-consensus and radicalness issues that often occur in the model. The results reveal many insights and provide valuable guidance for teachers to implement a multi-peer assessment system.     

Experienced teachers dealing with issues in education: a career perspective

This article reports on a qualitative study on the issues experienced teachers may encounter in everyday teaching practice. Some issues may possibly originate at the beginning of a career and continue to be a struggle during their career. Data were collected among 20 mid- and late career teachers from eight secondary schools. The results showed that at the current moment in their career, respondents of this study particularly recognised three issues: teacher–parent interaction, teaching versus other tasks and private life versus work. Teachers seldom talk about their issues, but more often than not they try to find a solution themselves or put up with the situation.     

中国人权政策简论

人权问题是当代国际关系中一个敏感而又富争议的话题，中国政府强调在人权问题上要加强对话与交流。中国政府有立足于本国国情的人权观，在人权问题上明确的原则立场，在参与国际人权事务交流以及维护发展中国与中国自身的根本利益方面作出了艰苦努力和重要贡献。西方国家企图利用人权问题干涉中国内政不得人心，中国政府捍卫本国主权的立场无比坚定。     

Mindfulness and discussing “thorny” issues in the classroom

Being in the moment, showing compassion, being non-judgmental, acknowledging deep emotional challenges without getting stuck: these are mindfulness characteristics important to us as teachers, yet not often included in teacher preparation. These concerns become magnified when we focus on difficult knowledge and thorny issues, like topics related to gender and race. Using a sociocultural framework, we address how mindfulness, heuristics, and other contemplative practices can be adopted to create safe, supporting, and healing spaces for such complex, often emotionally painful discussions. Participant narratives are used extensively to provide a voice to those marginalized or hurt. Drawing from these narratives and their experience in discussing thorny issues, we put forth possible solutions and interventions that can create spaces that encourage and support critical discourse through mindful practices. The development of a heuristic for discussing thorny issues whose characteristics can be adopted by interested teachers and educators to help frame and mediate this type of difficult discussion is an outcome of this research.     

Cognitive Illusions as Hindrances to Learning Complex Environmental Issues

Journal of Science Education and Technology - Teaching and learning complex issues is often confounded by the presence of simplistic mental models that are held by students. These simplistic models...