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   1233篇
  免费   50篇
管理学   143篇
民族学   9篇
人口学   80篇
丛书文集   6篇
理论方法论   108篇
综合类   3篇
社会学   745篇
统计学   189篇
  2023年   13篇
  2022年   5篇
  2021年   12篇
  2020年   29篇
  2019年   33篇
  2018年   30篇
  2017年   53篇
  2016年   39篇
  2015年   22篇
  2014年   32篇
  2013年   213篇
  2012年   54篇
  2011年   43篇
  2010年   46篇
  2009年   34篇
  2008年   38篇
  2007年   46篇
  2006年   45篇
  2005年   43篇
  2004年   51篇
  2003年   34篇
  2002年   28篇
  2001年   32篇
  2000年   23篇
  1999年   22篇
  1998年   16篇
  1997年   17篇
  1996年   21篇
  1995年   13篇
  1994年   9篇
  1993年   12篇
  1992年   11篇
  1991年   17篇
  1990年   13篇
  1989年   6篇
  1988年   12篇
  1987年   10篇
  1986年   18篇
  1985年   11篇
  1984年   11篇
  1983年   14篇
  1982年   10篇
  1981年   5篇
  1980年   5篇
  1979年   7篇
  1978年   4篇
  1976年   3篇
  1975年   4篇
  1974年   3篇
  1971年   3篇
排序方式: 共有1283条查询结果,搜索用时 484 毫秒
411.
At the highest levels of math achievement, gender differences in favor of men persist on standardized math tests. We hypothesize that stereotype threat depresses women's math performance through interfering with their ability to formulate problem-solving strategies. In Study 1, women underperformed in comparison to men on a word problemm test, however, women and me performed equally when the word problems were converted into their numerical equivalents. In Study 2, men and women worked on difficult problems, either in a high- or reduced-stereotype-threat condition. Problem-solving strategies were coded. When stereo-type threat was high, women were less able to formulate problem-solving strategies than when stereotype threat was reduced. The effect of stereotype threat on cognitive resources and the implications for gender differences in mathematical testing are discussed.  相似文献   
412.
Development of anti-cancer therapies usually involve small to moderate size studies to provide initial estimates of response rates before initiating larger studies to better quantify response. These early trials often each contain a single tumor type, possibly using other stratification factors. Response rate for a given tumor type is routinely reported as the percentage of patients meeting a clinical criteria (e.g. tumor shrinkage), without any regard to response in the other studies. These estimates (called maximum likelihood estimates or MLEs) on average approximate the true value, but have variances that are usually large, especially for small to moderate size studies. The approach presented here is offered as a way to improve overall estimation of response rates when several small trials are considered by reducing the total uncertainty.The shrinkage estimators considered here (James-Stein/empirical Bayes and hierarchical Bayes) are alternatives that use information from all studies to provide potentially better estimates for each study. While these estimates introduce a small bias, they have a considerably smaller variance, and thus tend to be better in terms of total mean squared error. These procedures provide a better view of drug performance in that group of tumor types as a whole, as opposed to estimating each response rate individually without consideration of the others. In technical terms, the vector of estimated response rates is nearer the vector of true values, on average, than the vector of the usual unbiased MLEs applied to such trials.  相似文献   
413.
In this article, we discuss an outage‐forecasting model that we have developed. This model uses very few input variables to estimate hurricane‐induced outages prior to landfall with great predictive accuracy. We also show the results for a series of simpler models that use only publicly available data and can still estimate outages with reasonable accuracy. The intended users of these models are emergency response planners within power utilities and related government agencies. We developed our models based on the method of random forest, using data from a power distribution system serving two states in the Gulf Coast region of the United States. We also show that estimates of system reliability based on wind speed alone are not sufficient for adequately capturing the reliability of system components. We demonstrate that a multivariate approach can produce more accurate power outage predictions.  相似文献   
414.
This study examined confiding patterns in a national sample of 1000 U.S. adults aged 25–70 to inform the development of an educational program for confidants, called Marital First Responders. Results showed that 73% of U.S. adults have been a confidant to someone with a problem in a marriage or long‐term committed relationship. The most common confiding relationship was between friends, followed by siblings. Confidants reported a wide range of problems brought to them, ranging from everyday complaints to serious issues such as infidelity and divorce. Confiders identified the most and least helpful responses. Findings suggest that naturally occurring confiding relationships have considerable potential to be the first level of help for troubled couple relationships.  相似文献   
415.
The 1984 federal Comprehensive Crime Control Act (CCCA) included a provision that permitted local law enforcement agencies to acquire up to 80% of the proceeds derived from civil asset forfeitures obtained in joint operations with federal authorities. We investigate how this rule governing forfeited assets influenced crime and police incentives by taking advantage of pre‐existing differences in state‐level civil asset forfeiture law and the timing of the CCCA. We find that after the CCCA was enacted crime fell about 17% in places where the federal law allowed police to retain more of their seized assets than state law previously allowed. (JEL K42, K15, H76)  相似文献   
416.
417.
A central theme of welfare reform is that recipients are required to engage in work activities. In many states, these work requirements apply to mothers whose children are a few months old, which may increase the costs and decrease the prevalence of breast-feeding. Given the substantial benefits of breast-feeding, any reduction represents an important negative consequence of these requirements. Our results suggest that in the absence of welfare reform, the national breast-feeding rate six months after birth would have been 5.5% higher in 2000. Such negative consequences of these policies must be weighed against potential benefits as states refine their welfare programs.  相似文献   
418.
419.
Recent changes in older men's retirement patterns are investigated for the United States. The results show that labor force incumbents, particularly those in secondary occupations, experienced increases in the volume of both retirement and reentry to the labor force. In addition, although working life expectancy remained relatively stable across occupations, men in secondary occupations spent increasingly greater portions of their work lives in postretirement jobs. Finally, large increases in nonworking life expectancy occurred because of substantial increases in life expectancy. In several occupations, however, declines in working life expectancy were major contributors to increases in nonworking life expectancy.  相似文献   
420.
Like much of the general public, the vast majority of my students strongly hold dichotomous, essentialist outlooks about what the categories female and male/gay and straight are supposed to represent and be. One way that I have found to challenge these oppressive worldviews, and also to queer my classes in the process, is to take my course participants to drag shows and/or to use videotapes of drag queens and drag kings in my classes. As part of an ongoing ethnography of drag performers I am undertaking, I have taken over 300 students to drag shows over the past eight years. Female students have often found attending a drag show to be a fun experience free of the sexual harassment found in most bars, while male students often contextually experience being a social minority for the first time in their life. From both attending drag shows and/or watching recordings of them I show in class, students have reported gaining an experiential appreciation of the performed basis of gender, sexuality, and inequality. Or, stated slightly differently, students begin to understand how the stratification system metaphorically makes drag queens of us all. This, in turn, provides the basis of the foremost argument I make in all my classes: equality will not be realized until nondichotomous, truly new ways of relating to others are envisioned and acted upon.  相似文献   
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