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   21037篇
  免费   331篇
管理学   3130篇
民族学   139篇
人才学   2篇
人口学   3241篇
丛书文集   58篇
理论方法论   1590篇
综合类   606篇
社会学   9108篇
统计学   3494篇
  2023年   56篇
  2021年   71篇
  2020年   136篇
  2019年   211篇
  2018年   1851篇
  2017年   1959篇
  2016年   1341篇
  2015年   260篇
  2014年   287篇
  2013年   1847篇
  2012年   730篇
  2011年   1397篇
  2010年   1274篇
  2009年   1008篇
  2008年   1080篇
  2007年   1253篇
  2006年   230篇
  2005年   511篇
  2004年   517篇
  2003年   502篇
  2002年   408篇
  2001年   305篇
  2000年   276篇
  1999年   251篇
  1998年   193篇
  1997年   179篇
  1996年   208篇
  1995年   147篇
  1994年   145篇
  1993年   154篇
  1992年   156篇
  1991年   148篇
  1990年   153篇
  1989年   139篇
  1988年   152篇
  1987年   141篇
  1986年   126篇
  1985年   156篇
  1984年   134篇
  1983年   126篇
  1982年   106篇
  1981年   104篇
  1980年   96篇
  1979年   104篇
  1978年   94篇
  1977年   65篇
  1976年   73篇
  1975年   73篇
  1974年   66篇
  1973年   56篇
排序方式: 共有10000条查询结果,搜索用时 890 毫秒
131.
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   
132.
The authors consider the optimal design of sampling schedules for binary sequence data. They propose an approach which allows a variety of goals to be reflected in the utility function by including deterministic sampling cost, a term related to prediction, and if relevant, a term related to learning about a treatment effect To this end, they use a nonparametric probability model relying on a minimal number of assumptions. They show how their assumption of partial exchangeability for the binary sequence of data allows the sampling distribution to be written as a mixture of homogeneous Markov chains of order k. The implementation follows the approach of Quintana & Müller (2004), which uses a Dirichlet process prior for the mixture.  相似文献   
133.
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   
134.
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   
135.
136.
137.
138.
Gay affirmative practice has recently been introduced into the social work literature as a culturally sensitive model for working with gay, lesbian, and bisexual (GLB) adults, however, this model has rarely been applied to practice with GLB youth. In this article, the authors review the literature to present the main tenets of gay affirmative practice, outline the challenges that GLB youth face, and delineate the environmental and individual strengths that can be enhanced to promote well-being. The authors then apply the gay affirmative practice model to GLB youth, offering concrete information about the specific knowledge, attitudes, and skills that social workers should acquire to better serve the unique, yet diverse, needs of GLB youth.  相似文献   
139.
Cultural and professional associations are the expression of the modern society with structured organisations. The 19th century was the marking epoch of the constitution of associations in Germany. The involvement of associations in the political live, specially the professional ones, is typical in Germany. While political sciences focus on the analyses of interest representation and mediation functions of organisations, sociology research covers the full range of social, psychological, political and economical functions of organisations. Management and especially human resource management topics are presently gaining a growing importance within the research community which focuses on the cultural and professional organisations.  相似文献   
140.
To protect public-use microdata, one approach is not to allow users access to the microdata. Instead, users submit analyses to a remote computer that reports back basic output from the fitted model, such as coefficients and standard errors. To be most useful, this remote server also should provide some way for users to check the fit of their models, without disclosing actual data values. This paper discusses regression diagnostics for remote servers. The proposal is to release synthetic diagnostics—i.e. simulated values of residuals and dependent and independent variables–constructed to mimic the relationships among the real-data residuals and independent variables. Using simulations, it is shown that the proposed synthetic diagnostics can reveal model inadequacies without substantial increase in the risk of disclosures. This approach also can be used to develop remote server diagnostics for generalized linear models.  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