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   22248篇
  免费   360篇
  国内免费   2篇
管理学   3088篇
民族学   151篇
人口学   3469篇
丛书文集   49篇
理论方法论   1533篇
综合类   455篇
社会学   9702篇
统计学   4163篇
  2023年   86篇
  2021年   80篇
  2020年   233篇
  2019年   308篇
  2018年   2000篇
  2017年   2088篇
  2016年   1379篇
  2015年   309篇
  2014年   378篇
  2013年   2354篇
  2012年   778篇
  2011年   1450篇
  2010年   1306篇
  2009年   1022篇
  2008年   1128篇
  2007年   1304篇
  2006年   256篇
  2005年   436篇
  2004年   444篇
  2003年   373篇
  2002年   286篇
  2001年   249篇
  2000年   229篇
  1999年   203篇
  1998年   167篇
  1997年   170篇
  1996年   190篇
  1995年   143篇
  1994年   125篇
  1993年   162篇
  1992年   187篇
  1991年   167篇
  1990年   162篇
  1989年   139篇
  1988年   157篇
  1987年   128篇
  1986年   123篇
  1985年   121篇
  1984年   144篇
  1983年   137篇
  1982年   118篇
  1981年   85篇
  1980年   115篇
  1979年   127篇
  1978年   111篇
  1977年   98篇
  1976年   93篇
  1975年   106篇
  1974年   79篇
  1972年   74篇
排序方式: 共有10000条查询结果,搜索用时 468 毫秒
131.
132.
133.
134.
We consider the problem of density estimation when the data is in the form of a continuous stream with no fixed length. In this setting, implementations of the usual methods of density estimation such as kernel density estimation are problematic. We propose a method of density estimation for massive datasets that is based upon taking the derivative of a smooth curve that has been fit through a set of quantile estimates. To achieve this, a low-storage, single-pass, sequential method is proposed for simultaneous estimation of multiple quantiles for massive datasets that form the basis of this method of density estimation. For comparison, we also consider a sequential kernel density estimator. The proposed methods are shown through simulation study to perform well and to have several distinct advantages over existing methods.  相似文献   
135.
136.
We introduce a new class of problems that contains two existing classes: allocation problems with single-peaked preferences and bankruptcy problems. On this class, we analyze the implications of well-known properties such as Pareto optimality, strategy-proofness, resource-monotonicity, no-envy, equal treatment of equals, and two new properties we introduce, hierarchical no-envy and independence of nonbinding constraints. Unlike earlier literature, we consider rules that allow free-disposability. We present characterizations of a rule we introduce on this domain. We relate this rule to well-known rules on the aforementioned subdomains. Based on this relation, we present a characterization of a well-known bankruptcy rule called the constrained equal awards rule. Received: 22 June 2000/Accepted: 21 March 2002 This paper is based on the first chapter of my Ph.D. thesis submitted to the University of Rochester. I wish to thank my advisor, William Thomson, for helpful comments and suggestions.  相似文献   
137.
138.
139.
Summary. We propose a simple estimation procedure for a proportional hazards frailty regression model for clustered survival data in which the dependence is generated by a positive stable distribution. Inferences for the frailty parameter can be obtained by using output from Cox regression analyses. The computational burden is substantially less than that of the other approaches to estimation. The large sample behaviour of the estimator is studied and simulations show that the approximations are appropriate for use with realistic sample sizes. The methods are motivated by studies of familial associations in the natural history of diseases. Their practical utility is illustrated with sib pair data from Beaver Dam, Wisconsin.  相似文献   
140.
The liberalization of international financial flows and foreign direct investment has induced countries to use diverse measures to attract inflow of foreign capital and foreign direct investment, which is expected to have a positive effect on the growth of GDP and thus a positive effect on social welfare. Tax exemption, reduction of tax rate, tax holiday, or diverse subsidies are some of the most important measures used. In this paper we study international tax cooperation, i.e., countries change and especially reduce tax rate for corporate income or for asset revenues to attract inflow of foreign direct investment. Both theoretical and empirical studies have shown the sensibility of foreign direct investment decision with respect to tax rate differences between home countries and host countries. In general, more inflow of foreign direct investment can be expected if the tax rate of the home country is lower than that of foreign countries. This is the main reason for international tax cooperation. In this paper we propose a simple model to prove the sub-optimal Nash non cooperative solution in a two-country tax-competition game. The model shows that international tax cooperation can improve welfare of the participating countries. How to reach a cooperative solution for an international tax competition game (ITCG) is therefore an important issue for further discussions and studies. International institutions can play a crucial role to reach international tax cooperation or international tax harmonization.  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