首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   202篇
  免费   11篇
  国内免费   3篇
教育   80篇
科学研究   51篇
体育   31篇
综合类   14篇
信息传播   40篇
  2023年   2篇
  2022年   15篇
  2021年   47篇
  2020年   9篇
  2019年   5篇
  2018年   8篇
  2017年   1篇
  2016年   2篇
  2014年   10篇
  2013年   10篇
  2012年   9篇
  2011年   8篇
  2010年   9篇
  2009年   2篇
  2008年   8篇
  2007年   9篇
  2006年   6篇
  2005年   7篇
  2004年   13篇
  2003年   14篇
  2002年   2篇
  2001年   3篇
  2000年   1篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1995年   2篇
  1994年   1篇
  1990年   3篇
  1989年   5篇
  1985年   1篇
  1984年   1篇
排序方式: 共有216条查询结果,搜索用时 15 毫秒
31.
从中药软枣猕猴桃Ainidia arguta(Sieb et Zucc)Planth ex Miguel的叶正丁醇提取物中分离并鉴定了2种结晶性成分,经理化常数测定及光谱分析,证明为β—谷甾醇(β—Sitosterol)和2α3α,24—三羟基—12—烯—28—乌苏酸(2α,3α,24—trihydroxyurs—12—en—28—oicacid)均为首次从该植物中分得。  相似文献   
32.
We apply social network analysis methods to describe the evolution of the innovator network of Jena, Germany in the period from 1995 to 2001. We find this evolution to be directed towards an increasing focus on core competencies of the network. Further we analyse the network resulting from R&D cooperations and explain - by means of network regression techniques - that the job mobility of scientists and the technological overlap between the actors, rather than past cooperations, can best predict the resulting structure.  相似文献   
33.
This paper investigates the role of Information and Communication Technologies (ICTs) related knowledge flows for international market shares. Using bibliometric data on scientific publications, we analyse the relationship between the strength of 14 OECD countries in four ICT-related scientific fields and the ability of those countries to maintain and acquire export market shares in the OECD market, across 16 manufacturing industries over the period 1981-2003. We find that domestic and foreign ICT-related scientific knowledge flows have a positive and significant impact on export market shares in ICT industries, while only domestic flows positively affect export shares in non-ICT industries. We also find that small open economies benefit more than other countries from foreign knowledge flows both in ICT and in non-ICT industries.  相似文献   
34.
A multiproduct cost function is estimated for English higher education institutions using a panel of data from recent years. The panel approach allows estimation by means of a random parameter stochastic frontier model which provides considerable new insights in that it allows the impact on costs of inter-institutional differences in the cost function itself to be distinguished from inter-institutional differences in efficiency. The approach used here therefore resembles in some respects the non-parametric methods of efficiency evaluation. We report also on measures of average incremental cost of provision and on returns to scale and scope.  相似文献   
35.
The use of university-industry collaboration in the innovation process is viewed as a major driver of firm competitiveness. The organizational dynamics underlying successful external relationships, however, remain poorly understood. Using longitudinal case studies of 15 innovation projects, we examine how firms with varying degrees of experience in collaborating with universities and public research organizations rely on different social capital dimensions to achieve successful collaborations. We find that experienced firms establish external collaborations on the basis of cognitive social capital, but this basis is reinforced by relational social capital over time. Conversely, less experienced firms initially base their university collaborations on relational social capital, which is reinforced by cognitive social capital over time. Based on these findings, we theorize on the interplay of different dimensions of social capital in university-industry collaborations over time. Our study has important implications for the management of collaborative innovation projects. In particular, it provides guidance to enable less experienced firms to develop successful collaborations with university partners.  相似文献   
36.
In fast-paced and knowledge-intensive environments, licensing partnerships can be powerful levers for market expansion. Research on the management of technology-oriented licenses has nonetheless pointed out the risks of corrosive disputes caused by conflicting interests or misunderstandings among licensing partners. The choice made ex ante on mechanisms for resolving potential disputes is of prime importance in the execution of licensing exchanges. Although the legal literature has widely emphasized the advantages of arbitration towards litigation, public ordering remains the “default” option in managers’ eyes. By adopting a transaction cost economics logic, our study explores the conditions under which licensing partners may prefer arbitration over public ordering during the contractual-design phase. In accordance with our theoretical arguments, findings show that the occurrence of arbitration provisions increases when the coordination orientation adopted by licensing partners is extensive. In situations where both monitoring and coordination orientations are simultaneously extensive, results reveal a greater propensity to prefer arbitration over public ordering. Our research therefore supports the view that corporate decision-makers tend to favor the conciliatory stance and compromising awards typically associated with arbitration, only when exchanges are expected to be highly coordinative. Their preference for arbitration over litigation is magnified when the coordination orientation develops alongside the monitoring orientation.  相似文献   
37.
To spur technology transfer, emerging market policymakers often require foreign firms to form joint ventures (JVs) with domestic firms. Through knowledge spillovers, JVs may reduce technology acquisition costs for domestic firms. Yet domestic firm rents from JVs could discourage innovation through a cannibalization effect. Which force dominates is an empirical question. I address it with novel data on China's auto sector. In response to fuel economy standards requiring firms to upgrade technology or sacrifice quality, firms with JVs reduced quality and price relative to their counterparts. Consistent with cannibalization, firms with JVs drive the negative effect.  相似文献   
38.
上海世界游泳锦标赛是伦敦奥运会前最重要的一次热身比赛,对我国明确伦敦奥运战略发展规划与目标意义重大。采用文献资料法、数理统计法对2011年第14届世界游泳锦标赛的成绩进行分析,结果表明:世界泳坛金(奖)牌继续呈分流状态,美国队继续领跑世界泳坛,澳大利亚成绩继续滑落,中国进步显著,多国对抗的格局模式已经形成。  相似文献   
39.
采用问卷调查、专家访谈等研究方法,就当前我国女足U-14年龄段的训练目标的构建和管理进行分析。研究发现:当前我国急需根据女足U-14年龄段队员的身心特点和未来发展综合考量制定该年龄段全国统一的、科学的训练目标;训练目标主要包括全面的人格和道德品质培养、熟练的个人进攻和防守技能、良好的速度素质和核心力量、主动的足球意识和思维等;该年龄段训练目标可以采用划分训练分目标进行管理和划分阶段性训练目标并利用负反馈调节进行管理两种方式,确保训练目标的实现。  相似文献   
40.
Statt eines Abstracts Der gro?e "Philosoph aus Wien", Paul Feyerabend, lehrte in den 1970er Jahren auf dem H?hepunkt seiner akademischen Karriere stehend in Berkeley. In seinen Kurs waren jedes Semester Hunderte von Studenten eingeschrieben, seltsamerweise waren darunter auch viele Sportstudenten und Fu?ballspieler, denen an den amerikanischen Universit?ten bekanntlich eine nicht geringe Bedeutung zukommt. Was war der Grund für diese Anziehungskraft einer nicht leicht zu verstehenden Philosophie? Feyerabend versprach jedem Studenten schon in der ersten Vorlesungsstunde eine Eins für seinen Kurs – und fügte noch hinzu, dass es bei ihm natürlich keinerlei Prüfung oder Hausarbeiten g?be. Man bekam seine Eins selbst dann, wenn man niemals in die Vorlesung kam, was Feyerabend mit seinem tiefen Vertrauen in das alte Humboldtsche Erziehungsziel der akademischen Freiheit rechtfertigte. Als die Universit?tsverwaltung von dieser Sache Wind bekam, wurde Feyerabend gezwungen, zumindest eine Abschlussprüfung für seinen Kurs abzuhalten. Im n?chsten Semester h?ndigte der Professor zu Beginn der Prüfungsstunde ein Blatt aus, auf dem in gro?en Buchstaben feierlich das Wort "Abschlussprüfung" stand, und darunter hie? es einfach: "Erz?hle mir deinen Lieblingswitz!" Jeder Witz, auch der dümmste, wurde dann mit der Note Eins belohnt. Der Chronist dieser Anekdote berichtet, dass das Universit?tsmanagement auch diesem Verfahren bald ein Ende gemacht hatte – ohne zu sagen, mit welchen Methoden, und wie Feyerabend auf diesen Eingriff in seine akademische Lehrfreiheit reagiert hat.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号