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   34161篇
  免费   512篇
  国内免费   25篇
教育   24032篇
科学研究   3392篇
各国文化   356篇
体育   2976篇
综合类   23篇
文化理论   362篇
信息传播   3557篇
  2021年   337篇
  2020年   531篇
  2019年   765篇
  2018年   1057篇
  2017年   1017篇
  2016年   983篇
  2015年   624篇
  2014年   844篇
  2013年   6119篇
  2012年   762篇
  2011年   800篇
  2010年   662篇
  2009年   665篇
  2008年   724篇
  2007年   687篇
  2006年   650篇
  2005年   554篇
  2004年   615篇
  2003年   502篇
  2002年   534篇
  2001年   709篇
  2000年   760篇
  1999年   625篇
  1998年   375篇
  1997年   409篇
  1996年   458篇
  1995年   349篇
  1994年   366篇
  1993年   319篇
  1992年   505篇
  1991年   517篇
  1990年   516篇
  1989年   522篇
  1988年   473篇
  1987年   471篇
  1986年   437篇
  1985年   492篇
  1984年   388篇
  1983年   377篇
  1982年   318篇
  1981年   299篇
  1980年   305篇
  1979年   454篇
  1978年   323篇
  1977年   295篇
  1976年   255篇
  1975年   237篇
  1974年   242篇
  1973年   235篇
  1971年   218篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
61.
Looking for laws     
S. French 《Metascience》2006,15(3):437-469
  相似文献   
62.
What legal issues may arise in setting content or performance standards? What precedents are relevant? What practices are defensible?  相似文献   
63.
Conclusion Computer-based career systems should be the focal point of popular, and effective career development initiatives which are of tremendous benefit to individuals. Such initiatives also have the potential to significantly reduce public expenditures and enhance the nation's competitive position internationally. The key lies in helping people understand that we can no longer afford to neglect the career development needs of Americans.I am most grateful for this opportunity to share my thoughts with you. I encourage you to promote the use of computer-based career systems by defining their benefits in economic terms. However, be sure you can prove your system does more than simply entertain its users, or leave them with extensive computer printouts.Phillip S. Jarvis is Manager, Careerware Research and Product Design, STM Systems Corp., Ottawa, Ontario, Canada and the author of CHOICES. This is the text of a paper presented to the Annual Conference of the Association of Computer-Based Systems for Career Information ((ACSCI) in St. Louis, Missouri on December 2, 1988.  相似文献   
64.
There is limited information on the anthropometry, strength, endurance and flexibility of female rock climbers. The aim of this study was to compare these characteristics in three groups of females: Group 1 comprised 10 elite climbers aged 31.3 +/- 5.0 years (mean +/- s) who had led to a standard of 'hard very severe'; Group 2 consisted of 10 recreational climbers aged 24.1 +/- 4.0 years who had led to a standard of 'severe'; and Group 3 comprised 10 physically active individuals aged 28.5 +/- 5.0 years who had not previously rock-climbed. The tests included finger strength (grip strength, finger strength measured on climbing-specific apparatus), flexibility, bent arm hang and pull-ups. Regression procedures (analysis of covariance) were used to examine the influence of body mass, leg length, height and age. For finger strength, the elite climbers recorded significantly higher values (P < 0.05) than the recreational climbers and non-climbers (four fingers, right hand: elite 321 +/- 18 N, recreational 251 +/- 14 N, non-climbers 256 +/- 15 N; four fingers, left hand: elite 307 +/- 14 N, recreational 248 +/- 12 N, non-climbers 243 +/- 11 N). For grip strength of the right hand, the elite climbers recorded significantly higher values than the recreational climbers only (elite 338 +/- 12 N, recreational 289 +/- 10 N, non-climbers 307 +/- 11 N). The results suggest that elite climbers have greater finger strength than recreational climbers and non-climbers.  相似文献   
65.
66.
67.
68.
69.
70.
This article discusses the changing relationships of authors and publishers, the current trends and challenges they face, and the direction of these relationships in the future. As the STM publishing industry finds itself in the midst of significant technological and economic changes, this article provides background to these changes and looks at the key elements, including open access business development, institutional repository trends, and emerging public financing policies in the future.  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