Instant Messaging on Campus: Use and Integration in University Students' Everyday Communication     

《The Information Society》2008,24(2):105-115

This article reviews the body of research on the use and role of instant messaging (IM) in campus life, and how IM is a key part of university students' communication. IM is a synchronous form of communication, and its speed, availability information, and support for multiple conversations have made it appealing for young people. With university students, in particular, showing a heavy reliance on IM, researchers have shown great interest in how university students use IM and how it is integrated in their social and academic life. While studies are emerging in various disciplines, no attempt has been made to integrate the disparate findings and approaches. This article synthesizes key findings, provides a map of the literature, and discusses conceptual problems inherent in the study of IM and other information and communication technologies (ICTs) that will help researchers identify key areas of study and opportunities for future investigation.  相似文献   

城乡二元结构的制度变迁与城乡一体化   总被引：8，自引：0，他引：8  

朱志萍 《软科学》2008,22(6)

我国城乡二元结构内生于农业全面支持工业的赶超型发展战略和以户籍制度为核心的城乡分割体制,体现了强制性制度变迁的特征;而城乡二元结构的演变,则是强制性制度变迁和诱致性制度变迁共同作用的结果。因此,只有结合制度变迁的强制力和诱导力,通过统筹城乡发展、推进城乡一体化制度创新,才能够打破城乡二元结构的桎梏。  相似文献   

中国产业结构节能潜力分析   总被引：7，自引：1，他引：6  

张雷  黄园淅 《中国软科学》2008,(5):27-35

鉴于现代社会发展对能源消费依赖程度日益提高,认识和把握国家能源消费行为规律及其变化趋势已经成为社会能源节约的基本前提。本文通过结构演进-能源消费和结构演进-单位能耗两个模型,对美国、英国、法国、德国、日本和印度产业结构演进和能源消费情况进行了国际比较。分析的结果表明,在现代化建设初期,二产为主的结构演进对国家能源消费需求产生了明显的增速效应;随着多元化进程的不断加快,产业结构的能源消费需求的减速作用开始逐步显现,从而形成由升到降的倒"U"型曲线变化形态。作为世界重要的能源生产和消费国,中国在长期一边倒的部门发展政策影响下,刚性演进特征极大地制约了国家产业结构节能效应的发挥,单位GDP能耗居高不下。  相似文献   

论美国科学不端行为定义演变的几个趋向   总被引：2，自引：0，他引：2  

王阳  王希艳 《科学学研究》2008,26(2):255-260

 从1989年美国公共卫生局发布第一个正式“科学不端行为”定义,到2000年美国科学技术政策办公室的“研究不端行为”定义实现了定义的统一,美国科学不端行为的定义经历了十多年的争论,内涵发生了四个大的变化,一是取消模糊语言“其他行为”;二是加强对术语“捏造、篡改和剽窃”的解释;三是建立不端行为调查结论的判断依据;四是从“科学不端行为”转变为“研究不端行为”。  相似文献   

Rethinking the multi-level perspective of technological transitions   总被引：2，自引：0，他引：2  

Audley Genus  Anne-Marie Coles 《Research Policy》2008,37(9):1436-1445

In recent years numerous articles have been published which advocate a multi-level perspective (MLP) for the analysis of long-term technological transitions. This paper reviews current transitions research and considers the limitations of the MLP which need to be addressed to enhance understanding of processes of innovation affecting the transformation of technology and society. The paper suggests ways in which the MLP may be effectively rethought, based on more thoroughgoing application of a co-evolutionary concept of technological transitions.  相似文献   

Measuring the change in R&D efficiency of the Japanese pharmaceutical industry     

Akihiro Hashimoto  Shoko Haneda 《Research Policy》2008,37(10):1829-1836

This paper presents a data envelopment analysis (DEA)/Malmquist index methodology for measuring the change in R&D efficiency at both firm and industry levels. Letting each of ten firms in each year be a separate decision-making unit, and employing one input and three outputs in a DEA case of R&D activity input-output lag, we measure “total factor R&D efficiency” change of Japanese pharmaceutical firms for decade 1983-1992 as defined by the period of R&D input. Decomposing Malmquist index into catch-up and frontier shift components and using “cumulative indices” proposed in this study, we evaluate R&D efficiency change for each firm and empirically show that R&D efficiency of Japanese pharmaceutical industry has almost monotonically gotten worse throughout the study decade.  相似文献   

Institutionalizing end-user demand steering in agricultural R&D: Farmer levy funding of R&D in The Netherlands     

Laurens Klerkx  Cees Leeuwis 《Research Policy》2008,37(3):460-472

The purpose of this paper is to critically examine the institutionalization of demand-driven modes of working in the R&D planning process and reveal possible weaknesses, through an analysis of a system of collective R&D funding by farmers. The findings indicate that, although end-users have the opportunity to raise issues that lead to R&D, queries are influenced by several actors in the R&D planning process in such a way that they do not adequately reflect farmers’ innovation needs. Conclusions are that more emphasis is required on joint demand articulation and involvement of end-users and other stakeholders in the innovation process, and on the institutional development of R&D funding organizations in order to adopt a more inclusive view on innovation.  相似文献   

基于元胞自动机的莫莫格湿地土地覆被预测模拟   总被引：6，自引：0，他引：6  

胡茂桂  傅晓阳  张树清  宋开山  王宗明 《资源科学》2007,29(2):142-148

本文运用元胞自动机结合人工神经网络方法,利用1986年和2004年两时期的ETM遥感影像,对莫莫格国家级湿地自然保护区的土地覆被变化进行了动态的模拟和预测,探讨了元胞自动机模型在湿地土地覆被变化预测和湿地资源保护方面的重要作用,为湿地资源的动态监测与可持续发展提供参考和决策支持。在模型实现过程中,以正六边形元胞取代传统的四边形元胞,克服了传统四边形元胞各向异性的先天不足,减小了模型预测的误差。应用BP神经网络与元胞自动机相结合自动挖掘出元胞自动机模型的转换规则,不仅降低建立多种土地覆被类型预测模拟的难度,而且减少了人为的主观因素,提高了准确性。将模型应用到莫莫格湿地保护区,预测的结果与实际土地覆被类型比较得出预测精度达到约80%,通过对该地区未来34年土地覆被变化的预测,反映出了该地区耕地面积增大、湿地减少的生态环境变坏的趋势,为该保护区的管理和发展提供了参考。  相似文献   

19世纪后半叶北京地区人的季节性换装对气候变化的适应   总被引：2，自引：0，他引：2  

张学珍  方修琦  郑景云  萧凌波 《资源科学》2007,29(2):91-96

本文根据《翁同日记》中关于1868年～1898年季节性换装的记录和北京的器测温度记录,采用相关分析和回归分析方法,探讨了季节性换装的迟早与气候变化的关系。结果表明：①从1868年～1898年年内冷暖变化和季节性换装的平均状况来看,作者的衣冠质地随着温度的季节性变化而改变,但是任意一类衣冠对应的上半年的温度条件均比下半年偏高3℃～5℃,而且春季的换装速率比秋季慢;其中,后者是人对北京地区春季升温速率较秋季降温速率慢的气候特征做出的适应性响应;②从年际波动和变化趋势来看,上半年的变冷（暖）对应于季节性换装日期的推迟（提前）,下半年与之相反;1868年～1898年,上半年的季节性换装日期趋于推迟,下半年趋于提前,这是人对北京地区春季和秋季均呈变冷趋势的适应性响应。但是,人类季节性换装对不同时节冷暖变化响应的敏感性存在明显差异,对初春、暮春、秋初、秋末的响应较为敏感,特别是对秋末的响应最为敏感。  相似文献   

自主创新:我国自主品牌"质变"的催化剂     

钟荣丙 《科技与管理》2007,9(3):123-126

我国自主品牌建设仍处于漫长的量的积累阶段,需要自主创新的强烈催化。分析了自主创新催化我国自主品牌“质变”的有效途径,并建议从强化自主创新意识、完善自主创新机制、培育创新型人才、营造创新文化环境等方面增强企业自主创新能力,以催化自主品牌的快速“质变”。  相似文献