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   9342篇
  免费   228篇
管理学   1525篇
民族学   41篇
人口学   903篇
丛书文集   28篇
理论方法论   695篇
综合类   120篇
社会学   4082篇
统计学   2176篇
  2023年   55篇
  2021年   53篇
  2020年   145篇
  2019年   205篇
  2018年   312篇
  2017年   376篇
  2016年   282篇
  2015年   187篇
  2014年   259篇
  2013年   1550篇
  2012年   329篇
  2011年   290篇
  2010年   246篇
  2009年   227篇
  2008年   188篇
  2007年   237篇
  2006年   226篇
  2005年   193篇
  2004年   179篇
  2003年   173篇
  2002年   194篇
  2001年   239篇
  2000年   218篇
  1999年   183篇
  1998年   133篇
  1997年   129篇
  1996年   133篇
  1995年   109篇
  1994年   106篇
  1993年   101篇
  1992年   152篇
  1991年   129篇
  1990年   118篇
  1989年   113篇
  1988年   104篇
  1987年   93篇
  1986年   97篇
  1985年   109篇
  1984年   114篇
  1983年   125篇
  1982年   102篇
  1981年   89篇
  1980年   91篇
  1979年   96篇
  1978年   93篇
  1977年   82篇
  1976年   70篇
  1975年   69篇
  1974年   59篇
  1973年   58篇
排序方式: 共有9570条查询结果,搜索用时 265 毫秒
971.
The article extends Ng’s (Am Econ Rev 77(1):186–191, 1987) model of optimal taxation of diamond goods—goods that are valued solely for their costliness. We extend his findings by analyzing how other goods should be taxed in the presence of pure diamond goods; modified Ramsey rules are derived in a basic single-type model as well as in a two-type model with redistribution. One key finding, that may be surprising and rather provoking, is that close complements (hip hop music) to diamond goods (bling bling) should be heavily subsidized.  相似文献   
972.
G.J.S. Ross 《Statistics》2013,47(3):445-453
This is the first application of a new method for testing stationary random point processes. Consider the class of all stationary ergodic point processes on the real line with arbitrary dependences among the inter–point distances (spacing).The hypothesis is :The observed process φ is a homogeneous Poisson process or more (resp.less) regular than a Poisson process.The sample is the vector of the first n points t1, …,tn.There is a close relation between our method for testing and queueing theory: For finding an appropriate test statistic, we observe the behaviour of a single server queue with the input φ.A table of critical values is given.  相似文献   
973.

The twentieth century has been the hallmark for managing total productivity, where the emphasis is towards maximization of outputs commensurate with the consumption of inputs. This is being challenged now to evolve the world class manufacturing strategy requiring a paradigm shift. This shift is towards green productivity, which looks forward to socially appropriate production and consumption aiming at value innovation and resource conservation. This paper is an attempt to outline the concepts and experiential learning about green productivity.  相似文献   
974.
A new method for constructing interpretable principal components is proposed. The method first clusters the variables, and then interpretable (sparse) components are constructed from the correlation matrices of the clustered variables. For the first step of the method, a new weighted-variances method for clustering variables is proposed. It reflects the nature of the problem that the interpretable components should maximize the explained variance and thus provide sparse dimension reduction. An important feature of the new clustering procedure is that the optimal number of clusters (and components) can be determined in a non-subjective manner. The new method is illustrated using well-known simulated and real data sets. It clearly outperforms many existing methods for sparse principal component analysis in terms of both explained variance and sparseness.  相似文献   
975.
In modelling a system structure it is often important to test the constancy of the structural parameters. If the hypothesis of constant parameters is rejected we wish to characterize the parameter variation. In this paper we examine the usefulness of the MOSUMSQ test statistics for locating and characterizing the parameter variation in linear regression models. The means and the variances of the test statistics are given for non-random parameter variation. The observed path of the MOSUMSQ test statistics provides valuable knowledge about the time of the onset of the parameter change and whether it is instantaneous or gradual.  相似文献   
976.
For two given estimators of a parameter vector the covariance structure of their difference is used to compare them in terms of their mean square error matrices. The results obtained are applied to the covariance adjustment technique and regression  相似文献   
977.
This article aims to contribute to the discussion about the ethics of research on children when studying sensitive issues such as violence. The empirical analysis is based on the accounts given by children (11 377) who completed a computer‐based questionnaire about their experiences of violence (‘The Finnish Child Victim Survey 2008’) and their reflections on the survey. We argue that experiences of violence should not be excluded from the research agenda on children due to ethical reasons, but that a more sophisticated practice should be developed instead to meet the needs and rights of children as informants. © 2010 The Author(s). Journal compilation 2010 National Children’s Bureau and Blackwell Publishing Limited.  相似文献   
978.
Abstract

In the field of stress research it is often assumed that social support as well as coping behaviour contributes to feelings of health and well-being. However, until now it has not been altogether clear whether a main-effect model or a buffer model was the more appropriate for explaining the role of these factors in response to stressful situations. In this paper, a research project is described in which both the direct and indirect effects of social support and coping were studied in the work situation of nurses. The results offer more support for a main-effect model than for a buffer or moderating-effect model, especially with regard to the coping strategies ‘active problem-solving’ and ‘palliative behaviour’. However, some moderating effects on nurses‘ reactions to their work situation were found for social support and for ‘comforting cognitions’ as a coping strategy.  相似文献   
979.
Patriota and Lemonte [24] introduced a quite general multivariate normal regression model. This model considers that the mean vector and the covariance matrix share the same vector of parameters. In this paper we present some influence assessment for this model, such as the local influence, total local influence of an individual and generalized leverage which are discussed. Additionally, the normal curvatures for local influence studies are derived under some perturbation schemes.  相似文献   
980.
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