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   92802篇
  免费   2999篇
  国内免费   19篇
管理学   12528篇
民族学   565篇
人才学   26篇
人口学   7223篇
丛书文集   614篇
理论方法论   9562篇
综合类   2728篇
社会学   43621篇
统计学   18953篇
  2023年   511篇
  2021年   583篇
  2020年   1539篇
  2019年   2242篇
  2018年   2167篇
  2017年   3253篇
  2016年   2435篇
  2015年   2082篇
  2014年   2666篇
  2013年   18993篇
  2012年   2560篇
  2011年   2347篇
  2010年   2115篇
  2009年   2279篇
  2008年   2224篇
  2007年   2049篇
  2006年   2251篇
  2005年   2404篇
  2004年   2201篇
  2003年   1918篇
  2002年   2038篇
  2001年   2046篇
  2000年   1818篇
  1999年   1722篇
  1998年   1511篇
  1997年   1363篇
  1996年   1310篇
  1995年   1338篇
  1994年   1306篇
  1993年   1300篇
  1992年   1296篇
  1991年   1235篇
  1990年   1206篇
  1989年   1069篇
  1988年   1160篇
  1987年   1030篇
  1986年   920篇
  1985年   1092篇
  1984年   1159篇
  1983年   1028篇
  1982年   964篇
  1981年   872篇
  1980年   823篇
  1979年   889篇
  1978年   782篇
  1977年   704篇
  1976年   670篇
  1975年   652篇
  1974年   533篇
  1973年   449篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
311.
Ohne Zusammenfassung German translations by Monika Lütke-Daldrup.  相似文献   
312.
Summary Meta-analyses of sets of clinical trials often combine risk differences from several 2×2 tables according to a random-effects model. The DerSimonian-Laird random-effects procedure, widely used for estimating the populaton mean risk difference, weights the risk difference from each primary study inversely proportional to an estimate of its variance (the sum of the between-study variance and the conditional within-study variance). Because those weights are not independent of the risk differences, however, the procedure sometimes exhibits bias and unnatural behavior. The present paper proposes a modified weighting scheme that uses the unconditional within-study variance to avoid this source of bias. The modified procedure has variance closer to that available from weighting by ideal weights when such weights are known. We studied the modified procedure in extensive simulation experiments using situations whose parameters resemble those of actual studies in medical research. For comparison we also included two unbiased procedures, the unweighted mean and a sample-size-weighted mean; their relative variability depends on the extent of heterogeneity among the primary studies. An example illustrates the application of the procedures to actual data and the differences among the results. This research was supported by Grant HS 05936 from the Agency for Health Care Policy and Research to Harvard University.  相似文献   
313.
314.
315.
Understanding the role of sexualization in a depressed patient gives us the opportunity to re-examine the place of sexual activity in psychopathology. The self psychological concept of the mirror transference is used to explain the therapist's activity in the case illustration.  相似文献   
316.
This paper focuses upon an as yet under-explored factor believed to underlie most managerial and organizational behavior variables—work ideology. Work ideologies are surveyed for several convenience samples of students and managers to show their ability to be studied and that patterned differences may be discovered. In addition, the historical origins and meanings of four major work ideologies are discussed.  相似文献   
317.
The fitting of a straight line that must pass through (0, 0) is a frequently encountered application of linear regression. Many computer packages provide a least-squares option sometimes identified as NO INT, or even NOINT, or as ‘suppressing the intercept’. Often these procedures are invalid or do not correspond to the most suitable model. This paper questions the least-squares-line approach and suggests some alternatives. Two measures are proposed for comparing the fit of alternative models.  相似文献   
318.
319.
One hundred and sixty-four elite union leaders in the United States completed a survey to assess the condition of the American labor movement and the factors affecting it. The respondents included high-level international union and state federation officers, central labor presidents, and 58 shop stewards. This study compares the responses of these labor officials and finds that they have similar, negative assessments of the condition of the American labor movement. The study also finds that these leaders agree that the most important factors affecting the labor movement are collective bargaining rights, union leadership, union member solidarity, and the NLRB.  相似文献   
320.
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