全文获取类型
收费全文 | 1343篇 |
免费 | 56篇 |
专业分类
管理学 | 191篇 |
民族学 | 7篇 |
人才学 | 2篇 |
人口学 | 107篇 |
丛书文集 | 8篇 |
理论方法论 | 186篇 |
综合类 | 4篇 |
社会学 | 689篇 |
统计学 | 205篇 |
出版年
2023年 | 9篇 |
2021年 | 13篇 |
2020年 | 26篇 |
2019年 | 33篇 |
2018年 | 31篇 |
2017年 | 47篇 |
2016年 | 46篇 |
2015年 | 33篇 |
2014年 | 43篇 |
2013年 | 221篇 |
2012年 | 39篇 |
2011年 | 54篇 |
2010年 | 40篇 |
2009年 | 40篇 |
2008年 | 39篇 |
2007年 | 55篇 |
2006年 | 43篇 |
2005年 | 44篇 |
2004年 | 34篇 |
2003年 | 37篇 |
2002年 | 36篇 |
2001年 | 32篇 |
2000年 | 24篇 |
1999年 | 30篇 |
1998年 | 19篇 |
1997年 | 26篇 |
1996年 | 15篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 27篇 |
1992年 | 17篇 |
1991年 | 16篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 15篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 14篇 |
1976年 | 5篇 |
1975年 | 15篇 |
1974年 | 8篇 |
1973年 | 5篇 |
排序方式: 共有1399条查询结果,搜索用时 31 毫秒
1.
Proportional hazards are a common assumption when designing confirmatory clinical trials in oncology. This assumption not only affects the analysis part but also the sample size calculation. The presence of delayed effects causes a change in the hazard ratio while the trial is ongoing since at the beginning we do not observe any difference between treatment arms, and after some unknown time point, the differences between treatment arms will start to appear. Hence, the proportional hazards assumption no longer holds, and both sample size calculation and analysis methods to be used should be reconsidered. The weighted log‐rank test allows a weighting for early, middle, and late differences through the Fleming and Harrington class of weights and is proven to be more efficient when the proportional hazards assumption does not hold. The Fleming and Harrington class of weights, along with the estimated delay, can be incorporated into the sample size calculation in order to maintain the desired power once the treatment arm differences start to appear. In this article, we explore the impact of delayed effects in group sequential and adaptive group sequential designs and make an empirical evaluation in terms of power and type‐I error rate of the of the weighted log‐rank test in a simulated scenario with fixed values of the Fleming and Harrington class of weights. We also give some practical recommendations regarding which methodology should be used in the presence of delayed effects depending on certain characteristics of the trial. 相似文献
2.
Alison Snow Jones 《Journal of Family and Economic Issues》2002,23(1):3-25
The association between drinking and selected job characteristics among women aged 24 to 31 is examined. Using the 1989 NLSY, women are classified as alcohol abusers or dependent based on DSM-III-R criteria or as heavy drinkers based on reported frequency of six or more drinks. Heavy drinking is negatively associated with wage and non-wage compensation. These effects diminish when human capital measures are controlled. Current alcoholism and current and past heavy drinking are strongly negatively associated with years of schooling. The association between alcoholism and job compensation and characteristics is not as strong as that seen for heavy drinking. It is not known if this is a consequence of errors in identifying alcoholic women in population-based surveys. 相似文献
3.
A NOTE ON EVANESCENT PROCESSES 总被引:1,自引:0,他引:1
This note examines the connection between μ-invariant measures for the transition function of a continuous-time Markov chain and those of its q-matrix, Q. The major result establishes a necessary and aufficient condition for a convergent μ-invariant measure for Q to be μ-inhant for the minimal transition function, P, under the assumption that P is honest. This corrects Theorem 6 of Vere-Jones (1969) and the first part of Corollary 1 of Pollett (1986), both of which assert that the above conclusion holds in the absence of this condition. The error was pointed out by E.A. van Doom (1991) and the counterexample which be presented provides the basis for the present arguments. In determining where the error occurred in the original proof, we are able to identify a simple sufficient condition for μ-invariance. 相似文献
4.
Chris Jones 《Significance》2008,5(1):46-48
It rises massive and magnificent above Salisbury Plain. The extraordinary monoliths of Stonehenge leave us as impressed today as ever—and as baffled. Archaeologists argue about how it was made. Can statisticians tell the answer? Chris Jones thinks they can be of considerable assistance. 相似文献
5.
Steve Redhead 《The Sociological review》1991,39(3):479-486
This essay is partly a response to the recent ethnographic research carried out by Armstrong and Harris, and partly a survey of a more general set of interconnected discourses about football hooliganism as a social phenomenon over the past thirty years into which the work of Armstrong and Harris fits. Discourses on football hooliganism seemed to have proliferated just as the ‘object’ in question seems to have disappeared from public view; at least in Britain, if not in other parts of Continental Europe. Part of the problem lies in the difficulty of defining accurately what we mean by the highly contentious phrase ‘football hooliganism’, a term which has no specific referent in English or Scottish law and whose boundaries, or ‘field’, are demarcated by these various discourses or ‘disciplines’ themselves: namely legal, sociological, psychological, criminological, geographical, architectural and so on. The essay offers examples of approaches which might overcome some of the difficulties experienced in researching football hooliganism. 相似文献
6.
Rachel K. Jones 《Sociological inquiry》1993,63(3):351-361
Victims of spouse abuse were interviewed concerning their views of why their husbands were abusive. It was hypothesized that by concentrating on one specific characteristic of this kind previously undocumented patterns of response would be elicited from the subjects. It was concluded that the women's reasons for the violence perpetrated by their spouses serve as justification for the abusers’actions and legitimize maintenance of the relationship. 相似文献
7.
Chandan Saha Michael P. Jones 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2005,67(1):167-182
Summary. In longitudinal studies, missingness of data is often an unavoidable problem. Estimators from the linear mixed effects model assume that missing data are missing at random. However, estimators are biased when this assumption is not met. In the paper, theoretical results for the asymptotic bias are established under non-ignorable drop-out, drop-in and other missing data patterns. The asymptotic bias is large when the drop-out subjects have only one or no observation, especially for slope-related parameters of the linear mixed effects model. In the drop-in case, intercept-related parameter estimators show substantial asymptotic bias when subjects enter late in the study. Eight other missing data patterns are considered and these produce asymptotic biases of a variety of magnitudes. 相似文献
8.
Brian D. Loader Steve Muncer Roger Burrows Nicholas Pleace & Sara Nettleton 《International Journal of Social Welfare》2002,11(1):53-65
The advent of thousands of Usenet groups on the Internet, covering a vast range of medical and welfare issues and ostensibly devoted to the mutual social support of participating members, has raised the potential for the development of new forms of 'virtual' health care. This article critically analyses the use by people with diabetes of one such Usenet group. It seeks to establish, first, the extent to which such a site provides some demonstrable measure of social support to its participants. This is approached by undertaking a structural analysis of the site to identify the extent of usage, and the nature of supporting interventions using a fivefold classification (instrumental, informational, esteem and social companionship and other). Second, the article attempts to identify any disparity between the lay health-knowledge in evidence and biomedical opinions proffered by the use of a panel of consultant diabetiologists. The results of the analysis suggest that the diabetes newsgroup provides an example of an active forum for largely well-informed participants who routinely use the media as an aid to the reflexive management of their medical condition. It also raises the prospect of a renegotiated relationship between medical knowledge and lay experience based upon shared learning 相似文献
9.
Rex Forehand Deborah J. Jones Gene H. Brody Lisa Armistead 《Journal of marriage and the family》2002,64(4):1012-1023
This study examined the unique and interactive roles of mother and teacher depressive symptoms in child adjustment in 277 African American single mother‐headed families, as well as whether the associations differed depending on the age and gender of the child. Findings revealed a significant association between maternal depressive symptoms and child depressive symptoms in girls, but not boys. Moreover, the combination of higher levels of both mother and teacher depressive symptoms was associated with the highest level of child depressive symptoms and, for younger children, externalizing symptoms. The importance of considering the multiple social contexts in which children interact is discussed. 相似文献
10.