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   25970篇
  免费   699篇
  国内免费   2篇
管理学   3691篇
民族学   98篇
人才学   1篇
人口学   2451篇
丛书文集   107篇
教育普及   2篇
理论方法论   2324篇
现状及发展   1篇
综合类   366篇
社会学   12431篇
统计学   5199篇
  2021年   139篇
  2020年   372篇
  2019年   516篇
  2018年   580篇
  2017年   823篇
  2016年   620篇
  2015年   482篇
  2014年   612篇
  2013年   4295篇
  2012年   833篇
  2011年   784篇
  2010年   606篇
  2009年   513篇
  2008年   638篇
  2007年   648篇
  2006年   619篇
  2005年   573篇
  2004年   512篇
  2003年   486篇
  2002年   540篇
  2001年   664篇
  2000年   660篇
  1999年   575篇
  1998年   445篇
  1997年   412篇
  1996年   432篇
  1995年   398篇
  1994年   356篇
  1993年   397篇
  1992年   455篇
  1991年   421篇
  1990年   396篇
  1989年   374篇
  1988年   378篇
  1987年   347篇
  1986年   321篇
  1985年   352篇
  1984年   366篇
  1983年   337篇
  1982年   296篇
  1981年   238篇
  1980年   248篇
  1979年   285篇
  1978年   243篇
  1977年   229篇
  1976年   194篇
  1975年   230篇
  1974年   179篇
  1973年   162篇
  1972年   140篇
排序方式: 共有10000条查询结果,搜索用时 740 毫秒
181.
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   
182.
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   
183.
184.
185.
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   
186.
187.
188.
189.
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   
190.
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