发动机代用燃料的发展探索

代用燃料是传统发动机燃料(如汽油和柴油)的替代品。在选择代用燃料时要考虑可供生产代用燃料的国家资源情况、工业发展水平、生产代用燃料的技术及效益、热机的适应性及发展趋势、环境保护等。我国是世界上应用与研究代用燃料较早的国家之一。经过长期研究,取得了一定的成果。在20世纪初,国外的许多国家就对代用燃料进行探索研究,美国、瑞典、日本等国家在代用燃料研究方面取得突出的成果。     

替代燃料汽车的持有者成本研究

替代燃料汽车能否为汽车消费者所接受，是其能否替代传统汽油发动机汽车从而实现石油替代的关键。本文应用生命周期理论，从汽车持有者的角度分析了汽车的持有者成本构成，建立了一个有广泛应用潜力的持有者成本模型，对替代燃料汽车的替代过程和效应进行分析，通过案例研究，给出了一系列战略建议。本文从持有者角度进行研究，为我国的替代燃料汽车系统的发展战略和机制的研究提供了新的视角，建立的持有者成本模型是一个有效的交通能源政策分析工具。     

Developing a Better Understanding of the Relationship Between Transpiration and Water Uptake in Plants

Performance on a multiple-choice item in a public examination indicates that most students do not understand the principle of the bubble potometer and its limitations in measuring transpiration rate. Teaching strategies are suggested to overcome these problems by helping students to compare the bubble potometer with the weighing method, develop the concept of assumptions, and resolve cognitive conflicts. To rectify the alternative conception on the role of transpiration, an interactive activity is designed to guide students to expose their preconceptions, design investigations to test them and evaluate the validity of the original ideas.     

Sociology of education: a personal reflection on politics,power and pragmatism

Abstract

This paper attempts to work on a number of different levels. Firstly, it comprises my personal reflections on a career in sociology of education. These reflections are entwined with a history of the discipline that emphasises themes of power, politics and pragmatism. This subjective, and inevitably partial, account is combined with an examination of the structure and composition of the academic field of sociology of education and its relationship with the two disciplines it originates from, sociology and education, but also with the wider field of politics. The ways in which these different strands within sociology of education coalesce or diverge, and the consequences in terms of tensions, fissures and struggles within the field will be considered. I also discuss the subject and content of sociology of education, and its future possibilities for radical as opposed to reactionary or reformist agendas.     

Computer technology futures for the improvement of assessment

With a focus on the interaction between computer technology and assessment, we first review the typical functions served by technology in the support of various assessment purposes. These include efficiencies in person and item sampling and in administration, analysis, and reporting. Our major interest is the extent to which technology can provide unique opportunities to understand performance. Two examples are described: a tool-based knowledge representation approach to assess content understanding and a team problem-solving task involving negotiation. The first example, using HyperCard as well as paper-and-pencil variations, has been tested in science and history fields. Its continuing challenge is to determine a strategy for creating and validating scoring criteria. The second example, involving a workforce readiness task for secondary school, has used expert-novice comparisons to infer performance standards. These examples serve as the context for the exploration of validity, equity, and utility.     

一类二阶非线性方程三点边值问题解的存在性

研究了一类二阶非线性常微分方程三点边值问题的非平凡解的存在性u″ f(t,u)=0,0≤t≤1,u′(0)=0,u(1)=αu(η);α∈R,0<η<1,f∈C([0,1]×R,R)。利用Leray-Schauder非线性诀择定理得到了非平凡解存在的一个充分条件,并给出一个实际例子的解法。     

Alternative education and social justice: considering issues of affective and contributive justice

This article considers the ways in which three alternative education sites in Australia support socially just education for their students and how injustice is addressed within these schools. The article begins with recognition of the importance of Nancy Fraser’s work to understandings of social justice. It then goes on to argue that her framework is insufficient for understanding the particularly complex set of injustices that are faced by many highly marginalised young people who have rejected or been rejected by mainstream education systems. We argue here for the need to consider the importance of ‘affective’ and ‘contributive’ aspects of justice in schools. Using interview data from the alternative schools, we highlight issues of affective justice raised by students in relation to their educational journeys, as well as foregrounding teachers’ affective work in schools. We also consider curricular choices and pedagogical practices in respect of matters of contributive justice. Our contention is that the affective and contributive fields are central to the achievement of social justice for the young people attending these sites. Whilst mainstream schools are not the focus of this article, we suggest that the lessons here have salience for all forms of schooling.     

精神与物质的两难选择——曾树生人物形象的原型解读

从原型理论来阐释《寒夜》中的曾树生形象 ,其意义在于写出人类生活、特别是爱情婚姻生活中处于两难境地时的人的无可奈何的痛苦、艰难的选择 ,这种选择的过程愈是曲折 ,愈是痛苦 ,作品的魅力愈是巨大     

非线性三阶三点边值问题解的存在性

利用Leray—Schauder非线性抉择讨论了一类非线性项含一阶和二阶导数的三阶三点边值问题解的存在性。在非线性项f满足线性增长的限制的条件下,通过构造适当的Banach空间并证明了一个解的存在定理。     

教学服务型大学:独立学院转型发展的战略选择

独立学院作为高等教育体制改革的重要组成部分,面临高等教育市场结构的转型,教学服务型大学的定位成为独立学院增强核心竞争力,实现可持续发展的战略选择。厘定教学服务型大学的内涵,建立科学高效的教学服务体系成为当前研究的首要课题。