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   7943篇
  免费   191篇
  国内免费   2篇
管理学   1270篇
民族学   23篇
人口学   707篇
丛书文集   24篇
理论方法论   707篇
综合类   94篇
社会学   3991篇
统计学   1320篇
  2020年   96篇
  2019年   125篇
  2018年   147篇
  2017年   175篇
  2016年   170篇
  2015年   117篇
  2014年   165篇
  2013年   1343篇
  2012年   193篇
  2011年   211篇
  2010年   163篇
  2009年   154篇
  2008年   190篇
  2007年   183篇
  2006年   199篇
  2005年   186篇
  2004年   156篇
  2003年   132篇
  2002年   151篇
  2001年   163篇
  2000年   175篇
  1999年   144篇
  1998年   139篇
  1997年   121篇
  1996年   129篇
  1995年   131篇
  1994年   140篇
  1993年   131篇
  1992年   144篇
  1991年   156篇
  1990年   174篇
  1989年   144篇
  1988年   157篇
  1987年   136篇
  1986年   133篇
  1985年   135篇
  1984年   143篇
  1983年   133篇
  1982年   98篇
  1981年   80篇
  1980年   87篇
  1979年   113篇
  1978年   89篇
  1977年   70篇
  1976年   81篇
  1975年   52篇
  1974年   75篇
  1973年   52篇
  1971年   43篇
  1970年   44篇
排序方式: 共有8136条查询结果,搜索用时 15 毫秒
1.
In this paper, we consider the deterministic trend model where the error process is allowed to be weakly or strongly correlated and subject to non‐stationary volatility. Extant estimators of the trend coefficient are analysed. We find that under heteroskedasticity, the Cochrane–Orcutt‐type estimator (with some initial condition) could be less efficient than Ordinary Least Squares (OLS) when the process is highly persistent, whereas it is asymptotically equivalent to OLS when the process is less persistent. An efficient non‐parametrically weighted Cochrane–Orcutt‐type estimator is then proposed. The efficiency is uniform over weak or strong serial correlation and non‐stationary volatility of unknown form. The feasible estimator relies on non‐parametric estimation of the volatility function, and the asymptotic theory is provided. We use the data‐dependent smoothing bandwidth that can automatically adjust for the strength of non‐stationarity in volatilities. The implementation does not require pretesting persistence of the process or specification of non‐stationary volatility. Finite‐sample evaluation via simulations and an empirical application demonstrates the good performance of proposed estimators.  相似文献   
2.
Objectives: In the United States, HIV continues to disproportionately affect men who have sex with men. One promising area of research that may inform the development of behavioral interventions among male–male couples is within the realm of sexual agreements. Methods: The purpose of our analysis was to determine whether respondents who report having an open agreement or an agreement breakage also report a higher incidence of recent (within the previous 12 months) intimate-partner violence (IPV) compared to respondents who report having a monogamous agreement or no agreement breakage after controlling for demographic variables. Results: Results showed that men who have an open agreement are less likely to report recent physical IPV. Conclusions: The results highlight the need to develop dyadic behavior interventions that address sexual agreements and stress management.  相似文献   
3.
Population Research and Policy Review - The welfare state can be perceived as a safety net which helps individuals adjust to situations of risk or transition. Starting from this idea of the welfare...  相似文献   
4.
5.
This paper develops a unified model of dual and unitary job holding based on a Stone-Geary utility function. The model incorporates both constrained and unconstrained labor supply. Panel data methods are adapted to accommodate unobserved heterogeneity and multinomial selection into six mutually exclusive labor supply regimes. We estimate the wage and income elasticities arising from selection and unobserved heterogeneity as well as from the Stone-Geary Slutsky equations. The labor supply model is estimated with data from the British Household Panel Survey 1991–2008. Among dual job holders, our study finds that the Stone-Geary income and wage elasticities are much larger for labor supply to the second job compared with the main job. When the effects of selection and unobserved heterogeneity are taken account of, the magnitudes of these elasticities on the second job tend to be significantly reduced.  相似文献   
6.
7.
We find “green” labels increase residential property values by an average of 5%. This premium varies by label stringency and across market segments. Builders respond to the stringency of labels by strategically incorporating green features to achieve higher ratings. This strategy seems reasonable as there is no market premium for green features that lead to scores between label rating cutoff values. These results raise important questions as to how green label policies should be designed in order to foster the supply of green features. Gradations of green attributes are influential, particularly for highly rated homes. The most stringent labels have the greatest role at the high price end of the market. (JEL Q20, Q40, R31)  相似文献   
8.
9.
From the inception of the proportional representation movement it has been an issue whether larger parties are favored at the expense of smaller parties in one apportionment of seats as compared to another apportionment. A number of methods have been proposed and are used in countries with a proportional representation system. These apportionment methods exhibit a regularity of order, as discussed in the present paper, that captures the preferential treatment of larger versus smaller parties. This order, namely majorization, permits the comparison of seat allocations in two apportionments. For divisor methods, we show that one method is majorized by another method if and only if their signpost ratios are increasing. This criterion is satisfied for the divisor methods with power-mean rounding, and for the divisor methods with stationary rounding. Majorization places the five traditional apportionment methods in the order as they are known to favor larger parties over smaller parties: Adams, Dean, Hill, Webster, and Jefferson. Received: 5 August 2000/Accepted: 24 October 2001  相似文献   
10.
Conflict over water resources is a major problem throughout the world. This essay describes the long-standing and often successful effort to insulate decisions on how to allot water among contending users, and how to reduce water pollution along a 5000-mile international border. The effort has been fraught with political and scientific complexity. Yet, after more than 90 years of experience, it provides a model that other nations are beginning to examine as relevant to their own efforts to find solutions.  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