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   89236篇
  免费   2930篇
  国内免费   6篇
管理学   11343篇
民族学   552篇
人才学   26篇
人口学   6878篇
丛书文集   538篇
理论方法论   9459篇
综合类   2205篇
社会学   42367篇
统计学   18804篇
  2023年   511篇
  2021年   573篇
  2020年   1509篇
  2019年   2218篇
  2018年   2084篇
  2017年   3150篇
  2016年   2402篇
  2015年   2047篇
  2014年   2636篇
  2013年   18960篇
  2012年   2380篇
  2011年   2183篇
  2010年   1994篇
  2009年   2218篇
  2008年   2066篇
  2007年   1895篇
  2006年   2138篇
  2005年   2327篇
  2004年   2185篇
  2003年   1919篇
  2002年   2036篇
  2001年   1986篇
  2000年   1766篇
  1999年   1682篇
  1998年   1505篇
  1997年   1344篇
  1996年   1330篇
  1995年   1322篇
  1994年   1277篇
  1993年   1210篇
  1992年   1153篇
  1991年   1120篇
  1990年   1118篇
  1989年   955篇
  1988年   1063篇
  1987年   940篇
  1986年   832篇
  1985年   1025篇
  1984年   1078篇
  1983年   963篇
  1982年   890篇
  1981年   804篇
  1980年   781篇
  1979年   824篇
  1978年   705篇
  1977年   638篇
  1976年   593篇
  1975年   570篇
  1974年   459篇
  1973年   398篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
81.
China’s pension reform during the past three decades has allowed a majority of China’s population to be covered by a pension scheme. Of particular note has been the New Rural Pension Scheme (NRPS), a voluntary programme introduced starting in 2009. One goal of our analysis is to assess that pension scheme, using a variety of sources of information including data drawn from recent (2013 and 2015) nationwide China Health and Retirement Longitudinal Surveys (CHARLS). Our analysis involves an exploration of differences between the generosity and structure of the NRPS and other pension schemes currently in place. We also explore the feasibility of reforming the current “quasi-social pension” component of the NRPS by substituting a universal non-contributory social pension pillar. In connection with our assessment of the NRPS, we note the unusually low benefit levels for rural China.  相似文献   
82.
Journal of Risk and Uncertainty - Texas is the only state that does not mandate that employers carry workers’ compensation (WC) insurance coverage. In place of traditional WC, companies can...  相似文献   
83.
Journal of Nonverbal Behavior - Past research has demonstrated that children understand distinct emotion concepts and can accurately recognize facial expressions of distinct emotions by a young...  相似文献   
84.
Random effects regression mixture models are a way to classify longitudinal data (or trajectories) having possibly varying lengths. The mixture structure of the traditional random effects regression mixture model arises through the distribution of the random regression coefficients, which is assumed to be a mixture of multivariate normals. An extension of this standard model is presented that accounts for various levels of heterogeneity among the trajectories, depending on their assumed error structure. A standard likelihood ratio test is presented for testing this error structure assumption. Full details of an expectation-conditional maximization algorithm for maximum likelihood estimation are also presented. This model is used to analyze data from an infant habituation experiment, where it is desirable to assess whether infants comprise different populations in terms of their habituation time.  相似文献   
85.
This article proposes several estimators for estimating the ridge parameter k based on Poisson ridge regression (RR) model. These estimators have been evaluated by means of Monte Carlo simulations. As performance criteria, we have calculated the mean squared error (MSE), the mean value, and the standard deviation of k. The first criterion is commonly used, while the other two have never been used when analyzing Poisson RR. However, these performance criteria are very informative because, if several estimators have an equal estimated MSE, then those with low average value and standard deviation of k should be preferred. Based on the simulated results, we may recommend some biasing parameters that may be useful for the practitioners in the field of health, social, and physical sciences.  相似文献   
86.
Australia was settled as a colony of Britain from the 17th century, and its early history of violent occupation has gradually given way to a relatively peaceful, wealthy, multicultural society. As a post-colonial country, its people share characteristics with those of Britain, but, as a multicultural society, national identity is increasingly influenced by the cultures of many countries, from both the global North and South. In this paper, the question of Australia's placement as a country of the global North or South is explored. Considerations of geography, the economy, political regimes and national identity are the backdrop to an investigation of Australian scholarship and the attitudes of scholars to the inclusion of Australia as a country of the global South.  相似文献   
87.
88.
89.
90.
Statistics and Computing - This article focuses on the challenging problem of efficiently detecting changes in mean within multivariate data sequences. Multivariate changepoints can be detected by...  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