全文获取类型
收费全文 | 29175篇 |
免费 | 302篇 |
国内免费 | 1篇 |
专业分类
管理学 | 4233篇 |
民族学 | 115篇 |
人才学 | 2篇 |
人口学 | 2844篇 |
丛书文集 | 129篇 |
教育普及 | 3篇 |
理论方法论 | 2553篇 |
现状及发展 | 2篇 |
综合类 | 372篇 |
社会学 | 13765篇 |
统计学 | 5460篇 |
出版年
2023年 | 186篇 |
2021年 | 184篇 |
2020年 | 470篇 |
2019年 | 617篇 |
2018年 | 665篇 |
2017年 | 894篇 |
2016年 | 740篇 |
2015年 | 498篇 |
2014年 | 661篇 |
2013年 | 4672篇 |
2012年 | 943篇 |
2011年 | 864篇 |
2010年 | 657篇 |
2009年 | 581篇 |
2008年 | 672篇 |
2007年 | 688篇 |
2006年 | 649篇 |
2005年 | 655篇 |
2004年 | 612篇 |
2003年 | 559篇 |
2002年 | 635篇 |
2001年 | 747篇 |
2000年 | 761篇 |
1999年 | 664篇 |
1998年 | 489篇 |
1997年 | 454篇 |
1996年 | 449篇 |
1995年 | 446篇 |
1994年 | 387篇 |
1993年 | 406篇 |
1992年 | 474篇 |
1991年 | 431篇 |
1990年 | 404篇 |
1989年 | 430篇 |
1988年 | 410篇 |
1987年 | 365篇 |
1986年 | 366篇 |
1985年 | 419篇 |
1984年 | 404篇 |
1983年 | 374篇 |
1982年 | 318篇 |
1981年 | 263篇 |
1980年 | 251篇 |
1979年 | 315篇 |
1978年 | 261篇 |
1977年 | 236篇 |
1976年 | 205篇 |
1975年 | 223篇 |
1974年 | 182篇 |
1973年 | 177篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
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
113.
114.
115.
116.
It is well known that the unimodal maximum likelihood estimator of a density is consistent everywhere but at the mode. The authors review various ways to solve this problem and propose a new estimator that is concave over an interval containing the mode; this interval may be chosen by the user or through an algorithm. The authors show how to implement their solution and compare it to other approaches through simulations. They show that the new estimator is consistent everywhere and determine its rate of convergence in the Hellinger metric. 相似文献
117.
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
118.
119.
120.
FINNEY DJ 《Journal of the American Statistical Association》1948,43(244):566-571