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   7060篇
  免费   150篇
管理学   1025篇
民族学   24篇
人才学   6篇
人口学   635篇
丛书文集   22篇
理论方法论   664篇
综合类   79篇
社会学   3281篇
统计学   1474篇
  2023年   40篇
  2021年   46篇
  2020年   103篇
  2019年   156篇
  2018年   158篇
  2017年   235篇
  2016年   154篇
  2015年   122篇
  2014年   157篇
  2013年   1177篇
  2012年   261篇
  2011年   199篇
  2010年   158篇
  2009年   148篇
  2008年   173篇
  2007年   184篇
  2006年   168篇
  2005年   170篇
  2004年   163篇
  2003年   126篇
  2002年   155篇
  2001年   173篇
  2000年   135篇
  1999年   158篇
  1998年   129篇
  1997年   134篇
  1996年   90篇
  1995年   101篇
  1994年   117篇
  1993年   90篇
  1992年   101篇
  1991年   94篇
  1990年   100篇
  1989年   86篇
  1988年   115篇
  1987年   98篇
  1986年   93篇
  1985年   98篇
  1984年   86篇
  1983年   85篇
  1982年   76篇
  1981年   82篇
  1980年   70篇
  1979年   87篇
  1978年   71篇
  1977年   55篇
  1976年   67篇
  1975年   65篇
  1974年   41篇
  1973年   41篇
排序方式: 共有7210条查询结果,搜索用时 31 毫秒
911.
912.
A family of log-linear models are proposed to describe contingency tables in which one variable can be considered as the response to the remaining. The proposed models take into account the ordering nature of the response categories and have structure similar to that employed in polynomial regression. Stochastic ordering of the response distributions under the proposed models is discussed and the model-reduction techniques are developed. The proposed models are applied to two data sets previously analysed in the literature.  相似文献   
913.
Typically in the United States only one contractor (the developer or first producer) makes a weapon system because it is too expensive or for some other reason infeasible to develop a second source. Congress and higher headquarters are constantly challenging the Armed Services to add other sources who can competitively make their systems. This paper describes a method of analyzing this complex problem which often has very large monetary and other significant impacts. Procedures and a case study are presented which consider cost and other criteria which might be used to make the second source decision.  相似文献   
914.
There is now a marriage gap in presidential voting in the UnitedStates, with married people voting about 10%–15% moreRepublican than unmarried people. This voting difference developedin the 1972 election, and it is also evident in party identification.The proportion of unmarried people has doubled since 1964, sothis cleavage is important. The gap can be explained statisticallyin terms of race and income, but still may give politiciansthe opportunity to gain votes by appealing to voters on thebasis of family issues.  相似文献   
915.
916.
917.
In 1980, the U.S. Supreme Court vacated a revised occupational standard for benzene, stating that the Occupational Safety and Health Administration (OSHA) had failed to demonstrate that significant health risks existed under the current standard. This decision has been interpreted by OSHA as requiring the consideration of quantitative risk assessments, whenever possible, in the development of regulations for occupational carcinogens. In light of this decision, the available epidemiologic evidence was used to generate a quantitative risk assessment for benzene. Uncertainties regarding the levels and lengths of benzene exposure for the studied cohorts were incorporated into the analysis. Based on the one-hit model, the assessment indicates that a working lifetime exposure to benzene at the current permissible exposure level (10 ppm) poses a substantial excess risk of death from leukemia. This report discusses the calculation of the risk estimates, the basis for relying on certain assumptions, and the inherent limitations of using epidemiologic studies to quantify cancer risks.  相似文献   
918.
The multilateral approach to causation posits four possible causes which need to be considered in the assessment and treatment of discord between partners in a primary relationship. These causes include the precipitating event, the reaction of a person to the precipitating event, the interactional dynamics of the partners, and the goals and objectives of the relationship which are being frustrated. A multilateral approach permits a person to accept his or her own legitimate responsibility for behavior and feelings without a responsibility "underload" or "overload." The use of multilateral causation is intended as a therapeutic safeguard against oversimplification.  相似文献   
919.
920.
A mixture model for random graphs   总被引:1,自引:0,他引:1  
The Erdös–Rényi model of a network is simple and possesses many explicit expressions for average and asymptotic properties, but it does not fit well to real-world networks. The vertices of those networks are often structured in unknown classes (functionally related proteins or social communities) with different connectivity properties. The stochastic block structures model was proposed for this purpose in the context of social sciences, using a Bayesian approach. We consider the same model in a frequentest statistical framework. We give the degree distribution and the clustering coefficient associated with this model, a variational method to estimate its parameters and a model selection criterion to select the number of classes. This estimation procedure allows us to deal with large networks containing thousands of vertices. The method is used to uncover the modular structure of a network of enzymatic reactions.  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