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   23732篇
  免费   411篇
  国内免费   15篇
教育   17039篇
科学研究   2048篇
各国文化   221篇
体育   1987篇
综合类   13篇
文化理论   187篇
信息传播   2663篇
  2022年   188篇
  2021年   277篇
  2020年   407篇
  2019年   643篇
  2018年   903篇
  2017年   862篇
  2016年   756篇
  2015年   457篇
  2014年   714篇
  2013年   4620篇
  2012年   651篇
  2011年   663篇
  2010年   505篇
  2009年   505篇
  2008年   562篇
  2007年   493篇
  2006年   446篇
  2005年   416篇
  2004年   381篇
  2003年   366篇
  2002年   343篇
  2001年   486篇
  2000年   412篇
  1999年   370篇
  1998年   207篇
  1997年   213篇
  1996年   245篇
  1995年   240篇
  1994年   185篇
  1993年   204篇
  1992年   324篇
  1991年   303篇
  1990年   299篇
  1989年   301篇
  1988年   257篇
  1987年   303篇
  1986年   266篇
  1985年   307篇
  1984年   246篇
  1983年   212篇
  1982年   191篇
  1981年   165篇
  1980年   154篇
  1979年   260篇
  1978年   183篇
  1977年   170篇
  1976年   154篇
  1975年   141篇
  1974年   149篇
  1971年   140篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
991.
992.
993.
Figures relating to the document delivery service of NERMLS are given. NERMLS has collaborated with the Postgraduate. Medical Institute in Boston to improve standards in community hospital libraries by creating a core library of books and journals and training library supervisors to work in these libraries. Institutes have taken place in the Countway Library, and guidelines for library development in community hospitals have been drawn up. Activities of Regional Medical Programs in New England are discussed, and further plans of NERMLS described.  相似文献   
994.
995.
This paper describes a fast-growing variety of programs that directly enable adult learners to pursue educational and career plans within their communities. Educational brokering serves an intermediary role between individual clients and the vast array of educational resources in a region. This paper considers the missions of brokering—advisement, assessment, and advocacy—its organizational arrangements, and the sources of its support and development. Specific successes and impacts of brokering are presented, as is the importance of the brokering idea to several larger public policy issues. Efforts currently underway to expand brokering activities on a national level are also discussed.Dr. Heffernan is an Assistant Professor in the Department of Higher/Postsecondary Education at Syracuse University and is Coordinator of Research and Editor of theBulletin of the National Center for Educational Brokering. He has been assisted in the preparation of this article by Francis U. Macy and Donn F. Vickers, Director and Associate Director, respectively, of the National Center for Educational Brokering, 405 Oak Street, Syracuse, New York 13203.  相似文献   
996.
Science and trans-science   总被引:3,自引:0,他引:3  
Alvin M. Weinberg 《Minerva》1972,10(2):209-222
  相似文献   
997.
998.
In this study, we examined the effect of string vibration damping devices on reducing racket frame vibration transfer to the forearm. Twenty participants volunteered to hold a tennis racket stationary in a forehand and backhand stroking position while tennis balls were fired at 20 m x s(-1) towards two impact locations, the node of vibration and the dead spot. A three-way analysis of variance with repeated measures on damping condition, impact location and stroke condition was performed on the data. The resonant frequency of the hand-held racket was found to be approximately 120 Hz. No significant differences in amplitude of vibration at the resonant frequency were found for the wrist or the elbow when damped and non-damped impacts were compared. Impacts at the dead spot produced greater amplitudes of vibration (P < 0.01) but no interaction between impact location and string dampers was evident. The string dampers had no effect on the grip force used or the muscle electrical activity in the forearm after impact. In conclusion, we found that string dampers do not reduce the amount of racket frame vibration received at the forearm. We suggest that string dampers remain a popular accessory among tennis players because of their acoustic effects and psychological support rather than any mechanical advantage.  相似文献   
999.
The aim of the present study was to examine the factorial validity of the Test of Performance Strategies (TOPS; Thomas et al., 1999) among adolescent athletes using confirmatory factor analysis. The TOPS was designed to assess eight psychological strategies used in competition (i.e. activation, automaticity, emotional control, goal-setting, imagery, negative thinking, relaxation and self-talk,) and eight used in practice (the same strategies except negative thinking is replaced by attentional control). National-level athletes (n = 584) completed the 64-item TOPS during training camps. Fit indices provided partial support for the overall measurement model for the competition items (robust comparative fit index = 0.92, Tucker-Lewis index = 0.88, root mean square error of approximation = 0.05) but minimal support for the training items (robust comparative fit index = 0.86, Tucker-Lewis index = 0.81, root mean square error of approximation = 0.06). For the competition items, the automaticity, goal-setting, relaxation and self-talk scales showed good fit, whereas the activation, emotional control, imagery and negative thinking scales did not. For the practice items, the attentional control, emotional control, goal-setting, imagery and self-talk scales showed good fit, whereas the activation, automaticity and relaxation scales did not. Overall, it appears that the factorial validity of the TOPS for use with adolescents is questionable at present and further development is required.  相似文献   
1000.
Electrocortical and behavioral responses of low, moderate, and high physically active older adults were compared with a younger control group on neutral and incompatible conditions of a flankers task. Compared to younger adults, high and moderate active older adults exhibited increased event-related potentials component P3 amplitude for the incompatible condition at the frontal electrode site. For the neutral condition, only low active older adults exhibited decreased amplitude at the central-parietal site, compared to younger adults. P3 latency revealed the longest latencies for low active older adults, followed by moderate active, high active, and younger adults, respectively. Reaction time (RT) data revealed that younger adults exhibited faster RT compared to all three older groups. Results suggest that physical activity may improve executive control function in older adults by affecting the distribution of P3 amplitude, which has been related to memory and attentional processes, and by decreasing P3 latency, which relates to the speed of cognitive processing.  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