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   325篇
  免费   15篇
管理学   30篇
人口学   32篇
丛书文集   1篇
理论方法论   39篇
综合类   1篇
社会学   142篇
统计学   95篇
  2023年   5篇
  2022年   6篇
  2021年   3篇
  2020年   10篇
  2019年   20篇
  2018年   22篇
  2017年   28篇
  2016年   17篇
  2015年   6篇
  2014年   22篇
  2013年   57篇
  2012年   27篇
  2011年   9篇
  2010年   15篇
  2009年   6篇
  2008年   10篇
  2007年   7篇
  2006年   3篇
  2005年   8篇
  2004年   5篇
  2003年   5篇
  2002年   4篇
  2001年   1篇
  2000年   1篇
  1999年   6篇
  1998年   1篇
  1997年   2篇
  1996年   4篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   4篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
  1988年   3篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1976年   1篇
  1974年   1篇
  1965年   1篇
排序方式: 共有340条查询结果,搜索用时 15 毫秒
1.
Catastrophic events, such as floods, earthquakes, hurricanes, and tsunamis, are rare, yet the cumulative risk of each event occurring at least once over an extended time period can be substantial. In this work, we assess the perception of cumulative flood risks, how those perceptions affect the choice of insurance, and whether perceptions and choices are influenced by cumulative risk information. We find that participants' cumulative risk judgments are well represented by a bimodal distribution, with a group that severely underestimates the risk and a group that moderately overestimates it. Individuals who underestimate cumulative risks make more risk‐seeking choices compared to those who overestimate cumulative risks. Providing explicit cumulative risk information for relevant time periods, as opposed to annual probabilities, is an inexpensive and effective way to improve both the perception of cumulative risk and the choices people make to protect against that risk.  相似文献   
2.
Cronie  Ottmar  Moradi  Mehdi  Mateu  Jorge 《Statistics and Computing》2020,30(5):1221-1239
Statistics and Computing - As a workaround for the lack of transitive transformations on linear network structures, which are required to consider different notions of distributional invariance,...  相似文献   
3.
4.
In this paper, we study space–time generalized additive models. We apply the penalyzed likelihood method to fit generalized additive models (GAMs) for nonseparable spatio-temporal correlated data in order to improve the estimation of the response and smooth terms of GAMs. The results show that our space–time generalized additive models estimated response and smooth terms reasonable well, and in addition, the mean squared error, mean absolute deviation and coverage intervals improved considerably compared to the classic GAM. An application on particulate matter concentration in the North-Italian region of Piemonte is also presented.  相似文献   
5.
The reduction or the complete elimination of specific types of weapons, particularly the elimination of all weapons of mass destruction, is one of the most important challenges that the international community should face in the 21th century. In this paper, a group of proposals on the possible roles to be played by the International Atomic Energy Agency (IAEA), the Organisation for the Prohibition of Chemical Weapons (OPCW), the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO) and the Conference on Disarmament (CD) is included.  相似文献   
6.
Assessment of analytical similarity of tier 1 quality attributes is based on a set of hypotheses that tests the mean difference of reference and test products against a margin adjusted for standard deviation of the reference product. Thus, proper assessment of the biosimilarity hypothesis requires statistical tests that account for the uncertainty associated with the estimations of the mean differences and the standard deviation of the reference product. Recently, a linear reformulation of the biosimilarity hypothesis has been proposed, which facilitates development and implementation of statistical tests. These statistical tests account for the uncertainty in the estimation process of all the unknown parameters. In this paper, we survey methods for constructing confidence intervals for testing the linearized reformulation of the biosimilarity hypothesis and also compare the performance of the methods. We discuss test procedures using confidence intervals to make possible comparison among recently developed methods as well as other previously developed methods that have not been applied for demonstrating analytical similarity. A computer simulation study was conducted to compare the performance of the methods based on the ability to maintain the test size and power, as well as computational complexity. We demonstrate the methods using two example applications. At the end, we make recommendations concerning the use of the methods.  相似文献   
7.
To assess the employment opportunities of older job-changers in the years prior to retirement, this study examines the how the breadth of occupations in which they find employment narrows as they age past their prime working years and how this differs by gender and educational attainment. The results indicate that workers who change jobs in their early 50s find employment in a reasonably similar set of occupations as prime-age workers, with opportunities narrowing at older ages. They also indicate that job opportunities broadened significantly for better-educated older workers since the late 1990s. While job opportunities now narrow significantly for less-educated men in their late 50s, this narrowing primarily occurs in the early 60s for women and better-educated men. In contrast to previous research, the study finds that employer policies that emphasize hiring from within are less important barriers to the hiring of older job-seekers. The study also finds that the narrowing of job opportunities is associated with a general decline in job quality as measured by median occupational earnings, a decline associated with differences in occupational skill requirements and the underlying economic environment. These results suggest that older hiring is not as limited to a select few occupations as it had been in previous decades, and that policy reforms aimed at increasing opportunities and improving labor market fluidity might best be served if they focused on less-educated men.  相似文献   
8.
Urban Ecosystems - Latin America and the Caribbean (LAC) is one of the most urbanized and biologically diverse regions in the world but is often characterized by weak environmental governance and...  相似文献   
9.
The role of urban expansion on bee diversity is poorly understood, but it may play an important role in restructuring pollinator diversity observed in rural regions at the urban perimeter. We studied bee communities in two habitats essential for pollinators (residential gardens and semi-natural areas) at 42 sites situated at the edge of greater Montreal, Canada. Bee species richness, abundance and functional diversity all increased with urbanization in both habitat types, but gardens and semi-natural areas supported distinct bee communities with unique responses to urbanization in terms of species turnover. Compared to semi-natural sites, residential gardens supported bees that foraged from a greater number but a lower proportion of available plant species. Bees did not discriminate between exotic and indigenous plant species in either gardens or semi-natural sites and were attracted to flowers in either habitat irrespective of their origins. Protecting semi-natural ruderal areas and providing residential garden habitats for pollinators are both effective means of promoting regional bee diversity in urbanizing regions.  相似文献   
10.
The viewing time method (VT) is an indirect measure of sexual interest in which participants are usually asked to rate the sexual attractiveness of target stimuli while their response latencies are unobtrusively measured. Higher response latencies for a certain group of depicted individuals indicate sexual interest in that group. Contrary to the general assumption that the picture content accounts for this effect by eliciting affect- or attention-based response delays, we hypothesized that the attractiveness rating task might be responsible for the VT effect. To test this hypothesis, we used two different tasks. Our heterosexual and homosexual male participants (N = 50) were instructed to rate the attractiveness or the sex of the depicted individuals. As expected, VT effects only emerged in attractiveness rating trials. Based on these findings, we conclude that VT effects are task dependent and are unlikely to be caused by affective or attentional processes (at least when participants are instructed to rate the attractiveness of target stimuli). We argue that rating tasks in VT measures cause participants to use affect independent response strategies. These response strategies seem to undermine stimulus-driven processes (like increased attention directed toward salient stimuli) which were thought to cause VT effects according to previous hypotheses.  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