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   21842篇
  免费   415篇
  国内免费   1篇
管理学   3178篇
民族学   92篇
人才学   2篇
人口学   2067篇
丛书文集   100篇
教育普及   2篇
理论方法论   1965篇
现状及发展   1篇
综合类   286篇
社会学   10682篇
统计学   3883篇
  2023年   103篇
  2021年   134篇
  2020年   341篇
  2019年   444篇
  2018年   516篇
  2017年   714篇
  2016年   571篇
  2015年   424篇
  2014年   538篇
  2013年   3390篇
  2012年   726篇
  2011年   698篇
  2010年   505篇
  2009年   454篇
  2008年   518篇
  2007年   523篇
  2006年   525篇
  2005年   529篇
  2004年   485篇
  2003年   447篇
  2002年   491篇
  2001年   593篇
  2000年   588篇
  1999年   508篇
  1998年   375篇
  1997年   335篇
  1996年   359篇
  1995年   328篇
  1994年   306篇
  1993年   332篇
  1992年   373篇
  1991年   343篇
  1990年   306篇
  1989年   310篇
  1988年   309篇
  1987年   269篇
  1986年   263篇
  1985年   297篇
  1984年   289篇
  1983年   271篇
  1982年   234篇
  1981年   195篇
  1980年   181篇
  1979年   211篇
  1978年   187篇
  1977年   177篇
  1976年   142篇
  1975年   174篇
  1974年   133篇
  1973年   121篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
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   
122.
To reduce nonresponse bias in sample surveys, a method of nonresponse weighting adjustment is often used which consists of multiplying the sampling weight of the respondent by the inverse of the estimated response probability. The authors examine the asymptotic properties of this estimator. They prove that it is generally more efficient than an estimator which uses the true response probability, provided that the parameters which govern this probability are estimated by maximum likelihood. The authors discuss variance estimation methods that account for the effect of using the estimated response probability; they compare their performances in a small simulation study. They also discuss extensions to the regression estimator.  相似文献   
123.
Conventional unemployment statistics have two dimensions—size and date. Population-at-risk unemployment rates add a third dimension—time. They are unlikely to revolutionise our picture of the nature of unemployment, says Ray Thomas . But they do give a more accurate and comprehensive picture than existing measures, and provide new insights into old problems, such as indicating the importance of statistics of entrants in helping to explain geographical variation in unemployment.  相似文献   
124.
125.
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   
126.
127.
128.
Few researchers have examined organizational variation in the adoption of workplace drug testing, but innovation theory suggests that adoption is more likely when it is compatible with an organization's values, previously introduced ideas, and needs. Using data from the 1997 National Employee Survey, this research models the effects of organizational compatibility, industry, and establishment size on the adoption of drug testing. The data reveal that compatibility, as measured by an organization's rules orientation, presence of an employee assistance program, and mechanization, is associated with the adoption of drug testing. As predicted, the adoption of drug testing varies across industries and by establishment size.  相似文献   
129.
130.
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