全文获取类型
| 收费全文 | 24635篇 |
| 免费 | 346篇 |
| 国内免费 | 25篇 |
专业分类
| 教育 | 17383篇 |
| 科学研究 | 2020篇 |
| 各国文化 | 257篇 |
| 体育 | 2608篇 |
| 综合类 | 8篇 |
| 文化理论 | 234篇 |
| 信息传播 | 2496篇 |
出版年
| 2021年 | 273篇 |
| 2020年 | 392篇 |
| 2019年 | 599篇 |
| 2018年 | 810篇 |
| 2017年 | 740篇 |
| 2016年 | 744篇 |
| 2015年 | 440篇 |
| 2014年 | 585篇 |
| 2013年 | 4410篇 |
| 2012年 | 556篇 |
| 2011年 | 599篇 |
| 2010年 | 462篇 |
| 2009年 | 485篇 |
| 2008年 | 524篇 |
| 2007年 | 490篇 |
| 2006年 | 466篇 |
| 2005年 | 400篇 |
| 2004年 | 425篇 |
| 2003年 | 328篇 |
| 2002年 | 356篇 |
| 2001年 | 479篇 |
| 2000年 | 525篇 |
| 1999年 | 449篇 |
| 1998年 | 273篇 |
| 1997年 | 261篇 |
| 1996年 | 314篇 |
| 1995年 | 252篇 |
| 1994年 | 265篇 |
| 1993年 | 227篇 |
| 1992年 | 360篇 |
| 1991年 | 371篇 |
| 1990年 | 351篇 |
| 1989年 | 369篇 |
| 1988年 | 342篇 |
| 1987年 | 331篇 |
| 1986年 | 333篇 |
| 1985年 | 375篇 |
| 1984年 | 301篇 |
| 1983年 | 307篇 |
| 1982年 | 241篇 |
| 1981年 | 249篇 |
| 1980年 | 258篇 |
| 1979年 | 333篇 |
| 1978年 | 236篇 |
| 1977年 | 214篇 |
| 1976年 | 187篇 |
| 1975年 | 171篇 |
| 1974年 | 171篇 |
| 1973年 | 165篇 |
| 1971年 | 151篇 |
排序方式： 共有10000条查询结果，搜索用时 109 毫秒
51.
Medicine has made increasing use of meta-analysis, largely as a quantitative procedure for combining results of clinical trials. Meta-analysis begins with a comprehensive review of the literature. The next step is a systematic analysis of the quality and content of each study. Finally, results are combined statistically and conclusions are drawn from this new overview of the data. This paper presents a brief historical perspective on the use of meta-analysis in medicine with emphasis on the medical library. The authors conclude that in the future, medical librarians will play a significant role in the application of this useful technique. 相似文献
52.
This investigation was undertaken in an effort to establish physiological characteristics of soccer players and to relate them to positional roles. A total of 135 footballers (age 24.4 +/- 4.6 years) were assessed for body mass, % body fat, haemoglobin, maximal oxygen uptake (VO2 max), leg power, anaerobic capacity and speed prior to an English league season. The sample included 13 goalkeepers, 22 full-backs, 24 centre-backs, 35 midfield players and 41 forwards. The goalkeepers were significantly heavier (86.1 +/- 5.5 kg; P < 0.01) than all groups except the centre-backs, had significantly higher estimated body fat percentages than centre-backs, forwards, midfield players (P < 0.01) or full-backs (P < 0.05), significantly lower estimated VO2 max values (56.4 +/- 3.9 ml kg-1 min-1; P < 0.01) and were slowest over 60 m (12.71 +/- 0.42 s). The midfield players had the highest predicted VO2 max values (61.4 +/- 3.4 ml kg-1 min-1), this being significantly greater (P < 0.05) than for the centre-backs. The forwards were the fastest group over 60 m (12.19 +/- 0.30 s), being significantly quicker than goalkeepers or centre-backs (P < 0.01) and full-backs (P < 0.05). Anaerobic power, as well as knee extensor torques (corrected for body mass) and extensor-flexor ratios, were similar between groups. No difference in estimated body fat percentage was observed between any of the outfield players, and haemoglobin concentrations were similar among players of all positions.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
53.
John Marshall is best remembered asthe first resident director of the RockefellerFoundation's Study and Conference Center atBellagio. Yet, his influence on knowledge,thought, and practice rivalled that of any ofhis contemporaries at the Rockefeller. Thispaper describes how he `went about hisbusiness' as a Foundation officer, and examineshis contribution to the creation of atransatlantic community of like-mindedtheorists and practitioners of communications. 相似文献
54.
55.
56.
57.
GARRETT J. McAULIFFE 《Counselor Education & Supervision》1992,31(3):163-174
A case presentation method of group supervision, as practiced at a community college, is described. Developmental principles underlying this approach are presented. 相似文献
58.
59.
60.