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   88713篇
  免费   2946篇
  国内免费   4篇
管理学   12223篇
民族学   534篇
人才学   25篇
人口学   6817篇
丛书文集   514篇
理论方法论   9326篇
综合类   2096篇
社会学   41391篇
统计学   18737篇
  2023年   509篇
  2021年   566篇
  2020年   1527篇
  2019年   2206篇
  2018年   2072篇
  2017年   3134篇
  2016年   2365篇
  2015年   2044篇
  2014年   2636篇
  2013年   18832篇
  2012年   2285篇
  2011年   2067篇
  2010年   1914篇
  2009年   2153篇
  2008年   1979篇
  2007年   1782篇
  2006年   2042篇
  2005年   2231篇
  2004年   2117篇
  2003年   1830篇
  2002年   1948篇
  2001年   1935篇
  2000年   1736篇
  1999年   1653篇
  1998年   1489篇
  1997年   1331篇
  1996年   1286篇
  1995年   1299篇
  1994年   1275篇
  1993年   1263篇
  1992年   1242篇
  1991年   1185篇
  1990年   1152篇
  1989年   1016篇
  1988年   1078篇
  1987年   972篇
  1986年   858篇
  1985年   1038篇
  1984年   1091篇
  1983年   985篇
  1982年   915篇
  1981年   838篇
  1980年   803篇
  1979年   847篇
  1978年   758篇
  1977年   684篇
  1976年   647篇
  1975年   621篇
  1974年   514篇
  1973年   423篇
排序方式: 共有10000条查询结果,搜索用时 172 毫秒
721.
John T. Barr 《Risk analysis》1991,11(3):373-373
  相似文献   
722.
A growing body of empirical and theoretical research has concentrated on the overlaps and commonalities among chemical and non-chemical (behavioural) addictions. Pathological gambling has perhaps been the most widely researched behavioural addiction and some of this research has concerned the co-existing links between pathological gambling and alcohol/drug addiction in both the gambling substance abuser and the substance abusing gambler (i.e. cross addiction). This study was of an exploratory nature and attempted to gather information and data regarding gambling cross addictions in the UK. To achieve this, 456 letters were sent to all drug and alcohol helping agencies in England requesting such information. This yielded 210 returns (46% response rate). Results indicated that gambling cross addictions occur in both adults and adolescents and were almost exclusively a male condition. However, it must be noted only just over half of the responding agencies had encountered gambling cross addiction and reasons for this are speculated. Results also indicated the existence of various cross addicted subgroups including an adolescent subgroup who were addicted to fruit machines and abused solvents. Future research ideas are also discussed.A more detailed version of this paper is available from the author on request.  相似文献   
723.
724.
725.
726.
This article analyzes the determinants of contraceptive use in Bangladesh, focusing on the roles of demand for additional children and of family planning service supply. Data from the Matlab Family Planning Health Services Project are used to examine the contributions of these factors to the difference in prevalence of modern contraceptive use between the project area and a control area served by the government family planning and health programs. Results of multivariate analysis deriving from the Easterlin synthesis framework show the importance of family planning supply factors in reducing psychic and resource costs of fertility regulation and in activating latent demand for contraception. Demand for birth limiting and for birth spacing emerge as important explanatory factors; demand for birth spacing is greater in the project area, and both demand measures exert a stronger effect on contraceptive behavior in that area.  相似文献   
727.
We present an explicit characterization of the joint dependency structure of an n×p matrix normal random matrix such that the p-dimensional sample mean vector is independent of all translation invariant statistics.  相似文献   
728.
In this paper, the notion of average total inspection (ATI) is introduced to ChSP-4(c1,c2) sampling plans. Procedures have been developed for the construction and selection of ChSP-4(c1, c2 plans, minimizing ATI at a given process average, while protection to the consumer is given in terms of the (i) average outgoing quality limit and (ii) limiting quality level.A wide range of c1 and c2 values are considered for developing tables which cover almost all practical situations. The procedure described is similar to that of Dodge and Romig.  相似文献   
729.
While applying theclassical maximum likelihood method for a certain statistical inference problem, Smith and Weissman [5] have noted that there are conditions under which the likelihood function may be unbounded above or may not possess local maximizers. Ariyawansà and Templeton [1] have derived inference procedures for this problem using the theory of structural inference [2,3,4]. Based on numerical experience, and without proof, they state that the resulting likelihood functions possess unique, global maximizers, even in instances where the classical maximum likelihood method fails in the above sense. In this paper, we prove that under quite mild conditions, these likelihood functions that result from the application of the theory of structural inference are well-behaved, and possess unique, global maximizers. This research was supported in part by the Applied Mathematical Sciences subprogram of the U.S. Department of Energy under contract W-31-109-Eng-38 while the author was visiting the Mathematics and Computer Science Division of Argonne National Laboratory, Argonne, Illinois.  相似文献   
730.
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