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   10836篇
  免费   194篇
  国内免费   2篇
管理学   1497篇
民族学   64篇
人才学   3篇
人口学   971篇
丛书文集   70篇
理论方法论   1083篇
综合类   227篇
社会学   5522篇
统计学   1595篇
  2021年   54篇
  2020年   155篇
  2019年   252篇
  2018年   264篇
  2017年   375篇
  2016年   265篇
  2015年   200篇
  2014年   256篇
  2013年   1745篇
  2012年   356篇
  2011年   340篇
  2010年   274篇
  2009年   263篇
  2008年   255篇
  2007年   297篇
  2006年   262篇
  2005年   265篇
  2004年   246篇
  2003年   178篇
  2002年   217篇
  2001年   275篇
  2000年   233篇
  1999年   210篇
  1998年   172篇
  1997年   157篇
  1996年   156篇
  1995年   144篇
  1994年   150篇
  1993年   150篇
  1992年   151篇
  1991年   149篇
  1990年   152篇
  1989年   147篇
  1988年   133篇
  1987年   148篇
  1986年   116篇
  1985年   147篇
  1984年   157篇
  1983年   141篇
  1982年   123篇
  1981年   89篇
  1980年   111篇
  1979年   114篇
  1978年   103篇
  1977年   86篇
  1976年   88篇
  1975年   99篇
  1974年   94篇
  1973年   69篇
  1972年   61篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
Federal housing policy in the US across the postwar period supported the construction of new houses more than public provision or renovation of older structures as a means of ensuring a sufficient supply of quality dwellings. Understanding trends in new housing in particular is thus crucial to understanding the housing regime. Following Myers (Housing demography: Linking demographic structure and housing markets. University of Wisconsin Press, 1990; Housing Studies, 14, 473–490,1999), this paper conceptualizes historical change in the housing stock within a demographic framework as the movement of cohorts of households through cohorts of housing stock. Recent evidence suggests that a new cohort of houses arose in the 1980s and 1990s (larger with more amenities than past vintages), and that buyers of those new houses were increasingly affluent. In this paper, I link the succession to a new cohort of houses to household cohort succession and examine the increasing affluence of new house buyers by age and cohort, focusing especially on the entry of the Baby Boom generation exactly when the new cohort of houses arrived. I use US Census microdata for 1960–2000 to develop a cohort longitudinal dataset, and analyze historical change in stratification in new house ownership. I find significant shifts between cohorts in income inequality among new house buyers, with implications for the capacity of the housing regime to meet the future needs of an increasingly diverse population.
Rachel E. DwyerEmail:
  相似文献   
192.
A heteroscedastic regression based on the odd log-logistic Marshall–Olkin normal (OLLMON) distribution is defined by extending previous models. Some structural properties of this distribution are presented. The estimation of the parameters is addressed by maximum likelihood. For different parameter settings, sample sizes and some scenarios, various simulations investigate the performance of the heteroscedastic OLLMON regression. We use residual analysis to detect influential observations and to check the model assumptions. The new regression explains the mass loss of different wood species in civil construction in Brazil.  相似文献   
193.
This article reports the formulation and results of a multiple equation econometric model to relate retail sales by brand and package size to retail promotional variables for a branded, frequently purchased grocery product. Primary emphasis is placed on the formulation of the model as opposed to the results obtained from its use.  相似文献   
194.
195.
This paper considers the problem of selecting matched pairs of observations for the reduction of bias in statistical hypothesis testing. A Euclidean distance function is suggested for measuring the similarity between paired observations. The matching process is then formulated initially as an assignment problem. Alternative formulations of the problem that would reduce computational difficulty are considered.  相似文献   
196.
The purpose of this paper is to extend the sensitivity analysis methodology as it applies to linear programming. The methodology developed herein is concerned with those changes in a technological coefficient that cause simultaneous changes in the relevant cost coefficients of the objective function. By proceeding from the definitions of feasibility and optimality, the authors develop formulas for determining bounds on the extent to which a technological coefficient, which has a predetermined effect on the corresponding cost coefficient, can vary without changing the optimal set of activities. After the formulas are developed, their use is demonstrated on a product-mix problem. This technique is of interest because changes in the rate at which an input is utilized can be expected to change the cost per unit of a resulting product. This interdependence should be recognized whenever a sensitivity analysis is performed on a technological coefficient of either a cost minimization or a contribution margin maximization problem.  相似文献   
197.
198.
Experience with branch and bound algorithms indicates that computational time is a function of not only the size of the problem, but also the nature of the input data. This paper formulates statistically-based variables which describe certain characteristics of the input data and experimentally evaluates their ability to predict computational time for one branch and bound algorithm, the relative location of facilities or “plant layout” problem. Results suggest that the described experimental procedure may be useful for an a priori assessment of the computational difficulty of specific branch and bound problems.  相似文献   
199.
200.
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