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   97809篇
  免费   2994篇
  国内免费   18篇
管理学   13212篇
民族学   581篇
人才学   25篇
人口学   7990篇
丛书文集   642篇
教育普及   3篇
理论方法论   9824篇
现状及发展   2篇
综合类   2824篇
社会学   46500篇
统计学   19218篇
  2023年   513篇
  2021年   591篇
  2020年   1550篇
  2019年   2224篇
  2018年   2252篇
  2017年   3333篇
  2016年   2521篇
  2015年   2101篇
  2014年   2675篇
  2013年   19006篇
  2012年   2790篇
  2011年   2621篇
  2010年   2241篇
  2009年   2330篇
  2008年   2325篇
  2007年   2194篇
  2006年   2348篇
  2005年   2539篇
  2004年   2314篇
  2003年   2047篇
  2002年   2166篇
  2001年   2273篇
  2000年   2061篇
  1999年   1907篇
  1998年   1607篇
  1997年   1460篇
  1996年   1410篇
  1995年   1422篇
  1994年   1390篇
  1993年   1387篇
  1992年   1422篇
  1991年   1361篇
  1990年   1330篇
  1989年   1198篇
  1988年   1279篇
  1987年   1130篇
  1986年   1059篇
  1985年   1223篇
  1984年   1263篇
  1983年   1156篇
  1982年   1033篇
  1981年   936篇
  1980年   873篇
  1979年   976篇
  1978年   837篇
  1977年   743篇
  1976年   703篇
  1975年   691篇
  1974年   580篇
  1973年   495篇
排序方式: 共有10000条查询结果,搜索用时 671 毫秒
121.
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   
122.
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   
123.
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   
124.
125.
126.
127.
What do voters really know about party platforms and how do they perceive the contents? Are there any relationships between party election platforms and electoral behavior? Despite of much research on parties, there are hardly any answers to these questions. If political parties devise programmes in order to influence political attitudes or electoral behavior, it will be necessary that these programmes are read by people. But it seems to be unclear if and how people do so. This article shows clearly that voters don’t know much about party manifestoes. Still, programmes are more important for voters than many people believe. Programmes are also an important factor for electoral behavior. But there is still a lack of data to get evident results.  相似文献   
128.
129.
Using an increasing returns specification for distribution, an inverted U pattern between the share of distribution in gross domestic product and the level of development is shown to arise. A cross-section time-series data set is constructed and merged with one used to analyze the service sector. In contrast to the rising pattern found for services, an average time-series relation that exhibits an inverted U pattern is established. The empirical results are robust, for example, to choice of functional form and country and time period coverage. A similar pattern is found in the average cross-section (country) relation between distribution and development.  相似文献   
130.
Institutional Constraints and Deforestation: An Application to Mexico   总被引:1,自引:0,他引:1  
Following North (1990), this article hypothesizes that effective rural institutions may impose additional costs on tropical deforestation through agricultural conversion. This allows a formal agricultural household analysis of institutional constraints on deforestation and therefore a method of empirically testing whether there is any significant difference in the actual level of forest land conversion under institutional constraints compared to the level of conversion under pure open access. A dynamic panel analysis for agricultural planted area in Mexico at state level and over the 1960–85 period confirms that institutional constraints on land clearing affected deforestation during the pre-NAFTA era.  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