全文获取类型
收费全文 | 23128篇 |
免费 | 400篇 |
国内免费 | 15篇 |
专业分类
教育 | 16490篇 |
科学研究 | 2042篇 |
各国文化 | 219篇 |
体育 | 1972篇 |
综合类 | 13篇 |
文化理论 | 177篇 |
信息传播 | 2630篇 |
出版年
2022年 | 175篇 |
2021年 | 263篇 |
2020年 | 383篇 |
2019年 | 606篇 |
2018年 | 829篇 |
2017年 | 805篇 |
2016年 | 714篇 |
2015年 | 427篇 |
2014年 | 662篇 |
2013年 | 4468篇 |
2012年 | 639篇 |
2011年 | 651篇 |
2010年 | 472篇 |
2009年 | 488篇 |
2008年 | 552篇 |
2007年 | 484篇 |
2006年 | 430篇 |
2005年 | 417篇 |
2004年 | 380篇 |
2003年 | 361篇 |
2002年 | 351篇 |
2001年 | 480篇 |
2000年 | 396篇 |
1999年 | 365篇 |
1998年 | 207篇 |
1997年 | 218篇 |
1996年 | 243篇 |
1995年 | 238篇 |
1994年 | 183篇 |
1993年 | 203篇 |
1992年 | 325篇 |
1991年 | 304篇 |
1990年 | 302篇 |
1989年 | 299篇 |
1988年 | 256篇 |
1987年 | 305篇 |
1986年 | 268篇 |
1985年 | 307篇 |
1984年 | 247篇 |
1983年 | 213篇 |
1982年 | 193篇 |
1981年 | 166篇 |
1980年 | 154篇 |
1979年 | 260篇 |
1978年 | 185篇 |
1977年 | 171篇 |
1976年 | 157篇 |
1975年 | 146篇 |
1974年 | 149篇 |
1971年 | 143篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
851.
852.
M P Bryden 《Child development》1972,43(3):824-832
853.
M Vernon 《Exceptional children》1970,36(10):743-751
854.
855.
T M Hodges 《Bulletin of the Medical Library Association》1970,58(3):320-324
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
856.
857.
James M. Heffernan Ph.D. 《Innovative Higher Education》1977,1(2):111-123
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
858.
859.
860.
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