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   94460篇
  免费   2956篇
  国内免费   4篇
管理学   12923篇
民族学   551篇
人才学   25篇
人口学   7639篇
丛书文集   542篇
教育普及   3篇
理论方法论   9616篇
现状及发展   2篇
综合类   2217篇
社会学   44829篇
统计学   19073篇
  2023年   509篇
  2021年   575篇
  2020年   1526篇
  2019年   2211篇
  2018年   2178篇
  2017年   3247篇
  2016年   2464篇
  2015年   2075篇
  2014年   2641篇
  2013年   18890篇
  2012年   2579篇
  2011年   2407篇
  2010年   2066篇
  2009年   2227篇
  2008年   2126篇
  2007年   1980篇
  2006年   2169篇
  2005年   2379篇
  2004年   2234篇
  2003年   1986篇
  2002年   2085篇
  2001年   2184篇
  2000年   1986篇
  1999年   1831篇
  1998年   1572篇
  1997年   1431篇
  1996年   1385篇
  1995年   1395篇
  1994年   1356篇
  1993年   1359篇
  1992年   1377篇
  1991年   1317篇
  1990年   1283篇
  1989年   1144篇
  1988年   1224篇
  1987年   1089篇
  1986年   1006篇
  1985年   1173篇
  1984年   1225篇
  1983年   1110篇
  1982年   1003篇
  1981年   902篇
  1980年   853篇
  1979年   948篇
  1978年   820篇
  1977年   727篇
  1976年   687篇
  1975年   665篇
  1974年   557篇
  1973年   479篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
Acculturative stress in the adjustment of immigrant families   总被引:1,自引:0,他引:1  
This study reviews the issue of acculturative stress in immigrant families. Acculturative stress includes behaviors experienced by immigrants that are a direct consequence of the process of acculturation and adaptation to a new society. A number of stressors impacting on the acculturation of immigrant families is discussed. These stressors include lack of English language skills, employment and economic status, educational background, family life, and sociopolitical and immigration status.  相似文献   
112.
A class of symmetric bivariate uniform distributions is proposed for use in statistical modeling. The distributions may be constructed to be absolutely continuous with correlations as close to±1 as desired. Expressions for the correlations, regressions and copulas are found. An extension to three dimensions is proposed.  相似文献   
113.
The product of two independent or dependent scalar normal variables, sums of products, sample covariances, and general bilinear forms are considered. Their distributions are shown to belong to a class called generalized Laplacian. A growth-decay mechanism is also shown to produce such a generalized Laplacian. Sets of necessary and sufficient conditions are derived for bilinear forms to belong to this class. As a generalization, the distributions of rectangular matrices associated with multivariate normal random vectors are also discussed.  相似文献   
114.
115.
116.
To study the homogeneity and influences on scientists'perspectives of environmental risks, we have examined similarities and differences in risk perceptions, particularly regarding nuclear wastes, and policy preferences among 1011 scientists and engineers. We found significant differences ( p 0.05)in the patterns of beliefs among scientists from different fields of research. In contrast to physicists, chemists, and engineers, life scientists tend to: (a)perceive the greatest risks from nuclear energy and nuclear waste management; (b)perceive higher levels of overall environmental risk; (c)strongly oppose imposing risks on unconsenting individuals; and (d)prefer stronger requirements for environmental management. On some issues related to priorities among public problems and calls for government action, there are significant variations among life scientists or physical scientists. We also found that–independently of field of research–perceptions of risk and its correlates are significantly associated with the type of institution in which the scientist is employed. Scientists in universities or state and local governments tend to see the risks of nuclear energy and wastes as greater than scientists who work as business consultants, for federal organizations, or for private research laboratories. Significant differences also are found in priority given to environmental risks, the perceived proximity of environmental disaster, willingness to impose risks on an unconsenting population, and the necessity of accepting risks and sacrifices.  相似文献   
117.
The simple logistic regression model with normal measurement error and normal regressor is shown to be identifiable without any extra information about the measurement error. The multiple logistic regression model with more than one regressor variable measured with error is not identifiable. If the covariance matrix of the measurement error is known up to a scalar factor, the model is identified. Further we discuss why in spite of the identifiability the models cannot be estimated in a reasonable way without extra information about the measurement error.  相似文献   
118.
On the run length of a Shewhart chart for correlated data   总被引:1,自引:0,他引:1  
We consider an extension of the classical Shewhart control chart to correlated data which was introduced by Vasilopoulos/Stamboulis (1978). Inequalities for the moments of the run length are given under weak conditions. It is proved analytically that the average run length (ARL) in the in-control state of the correlated process is larger than that in the case of independent variables. The exact ARL is calculated for exchangeable normal variables and autoregressive processes (AR). Moreover, we compare this chart with residual charts. Especially, in the case of an AR(1)—process with positive coefficient, it turns out that the out-of-control ARL of the modified Shewhart chart is smaller than that of the Shewhart chart for the residuals.  相似文献   
119.
We present a new characterization technique extracted from a well known idea in statistical inference. We use the partial derivative of the logarithm of the survival function in connection with truncated moments to characterize several probability distributions. Our methods introduce a unified technique to obtain several well known results in a unified way.  相似文献   
120.
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