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   20604篇
  免费   356篇
  国内免费   1篇
管理学   2788篇
民族学   176篇
人才学   1篇
人口学   3480篇
丛书文集   36篇
理论方法论   1400篇
综合类   420篇
社会学   9370篇
统计学   3290篇
  2023年   109篇
  2022年   71篇
  2021年   114篇
  2020年   263篇
  2019年   332篇
  2018年   2014篇
  2017年   2092篇
  2016年   1429篇
  2015年   291篇
  2014年   408篇
  2013年   1964篇
  2012年   785篇
  2011年   1405篇
  2010年   1261篇
  2009年   971篇
  2008年   1021篇
  2007年   1159篇
  2006年   226篇
  2005年   412篇
  2004年   434篇
  2003年   377篇
  2002年   271篇
  2001年   195篇
  2000年   199篇
  1999年   192篇
  1998年   159篇
  1997年   149篇
  1996年   170篇
  1995年   124篇
  1994年   116篇
  1993年   114篇
  1992年   126篇
  1991年   136篇
  1990年   130篇
  1989年   149篇
  1988年   95篇
  1987年   115篇
  1986年   97篇
  1985年   120篇
  1984年   101篇
  1983年   104篇
  1982年   82篇
  1981年   84篇
  1980年   78篇
  1979年   82篇
  1978年   85篇
  1977年   60篇
  1976年   66篇
  1975年   64篇
  1974年   60篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
111.
112.
This article contributes to the ongoing debate on the economic determinants of fertility behavior by addressing the role of job insecurity in couples’ intentions concerning parenthood and its timing. It starts from the hypothesis that cultural values moderate individuals’ reactions to job insecurity and the way it is related to family formation. With a systematic thematic content analysis of a set of semi-structured interviews with childless men and women around the age of 30 in eastern and western Germany, we are able to show that there are substantial differences in the consequences of job insecurity on intentions to have a first child. In western Germany, a relatively secure job career is expected to precede family formation, and this sequence of transitions is rather rigid, whereas in eastern Germany job security and family formation are thought of and practiced as parallel investments. We suggest that the lack of convergence in family formation patterns between eastern and western Germany after the unification of the country in 1990 is partially related to different attitudes toward job insecurity in the two contexts.  相似文献   
113.
114.
American options in discrete time can be priced by solving optimal stopping problems. This can be done by computing so-called continuation values, which we represent as regression functions defined recursively by using the continuation values of the next time step. We use Monte Carlo to generate data, and then we apply smoothing spline regression estimates to estimate the continuation values from these data. All parameters of the estimate are chosen data dependent. We present results concerning consistency and the estimates’ rate of convergence.  相似文献   
115.
This paper proposes an experimental test to evaluate the performance of the serial cost sharing rule, originally proposed by Shenker [Sigmetrics, 241–242 (1990)] and then analyzed by Moulin and Shenker [Econometrica 60, 1009–1037 (1992)]. We report measures of the performance and efficiency of the serial mechanism by comparing the choices and payoffs attained by the subjects to the expected equilibrium allocations. Experimental evidence shows that learning is needed for the subjects to converge to the equilibrium strategy. However, in terms of efficiency, the serial mechanism leads to almost efficient allocations.  相似文献   
116.
In the paper we present a new method of calculating sampling intervals, so-called windows, allowing an experimenter some flexibility in timing the sample collection, while a minimum required design efficiency for parameter estimation is assured. The method is based on the Equivalence Theorem for D-optimality what makes the length of each window related to the parameter sensitivities. An example of calculating the windows in a pharmacokinetic study is presented. Some other methods of calculating efficient sampling windows are briefly discussed.  相似文献   
117.
Terrorist actions are aimed at maximizing harm (health, psychological, economical, and political) through the combined physical impacts of the act and fear. Immediate and effective response to a terrorist act is critical to limit human and environmental harm, effectively restore facility function, and maintain public confidence. Though there have been terrorist attacks in public facilities that we have learned from, overall our experiences in restoration of public facilities following a terrorist attack are limited. Restoration of public facilities following a release of a hazardous material is inherently far more complex than in industrial settings and has many unique technical, economic, social, and political challenges. For example, there may be a great need to quickly restore the facility to full operation and allow public access even though it was not designed for easy or rapid restoration, and critical information is needed for quantitative risk assessment and effective restoration must be anticipated to be incomplete and uncertain. Whereas present planning documents have substantial linearity in their organization, the “adaptive management” paradigm provides a constructive parallel paradigm for restoration of public facilities that anticipates and plans for uncertainty, inefficiencies, and stakeholder participation. Adaptive management grew out of the need to manage and restore natural resources in highly complex and changing environments with limited knowledge about causal relationships and responses to restoration actions. Similarities between natural resource management and restoration of a public facility after a terrorist attack suggest that integration of adaptive management principles explicitly into restoration processes will result in substantially enhanced and flexible responses necessary to meet the uncertainties of potential terrorist attacks.  相似文献   
118.
119.
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