全文获取类型
收费全文 | 27851篇 |
免费 | 736篇 |
专业分类
管理学 | 3366篇 |
民族学 | 145篇 |
人才学 | 6篇 |
人口学 | 2500篇 |
丛书文集 | 163篇 |
教育普及 | 5篇 |
理论方法论 | 2546篇 |
现状及发展 | 1篇 |
综合类 | 336篇 |
社会学 | 14294篇 |
统计学 | 5225篇 |
出版年
2023年 | 142篇 |
2021年 | 147篇 |
2020年 | 403篇 |
2019年 | 622篇 |
2018年 | 651篇 |
2017年 | 920篇 |
2016年 | 651篇 |
2015年 | 503篇 |
2014年 | 633篇 |
2013年 | 5095篇 |
2012年 | 885篇 |
2011年 | 833篇 |
2010年 | 646篇 |
2009年 | 599篇 |
2008年 | 687篇 |
2007年 | 691篇 |
2006年 | 664篇 |
2005年 | 602篇 |
2004年 | 575篇 |
2003年 | 523篇 |
2002年 | 548篇 |
2001年 | 684篇 |
2000年 | 597篇 |
1999年 | 601篇 |
1998年 | 446篇 |
1997年 | 395篇 |
1996年 | 456篇 |
1995年 | 451篇 |
1994年 | 443篇 |
1993年 | 422篇 |
1992年 | 472篇 |
1991年 | 468篇 |
1990年 | 455篇 |
1989年 | 427篇 |
1988年 | 406篇 |
1987年 | 366篇 |
1986年 | 359篇 |
1985年 | 387篇 |
1984年 | 383篇 |
1983年 | 332篇 |
1982年 | 285篇 |
1981年 | 244篇 |
1980年 | 264篇 |
1979年 | 266篇 |
1978年 | 224篇 |
1977年 | 216篇 |
1976年 | 192篇 |
1975年 | 192篇 |
1974年 | 146篇 |
1973年 | 122篇 |
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
51.
A sample size justification should be given for all clinical investigations. However, sometimes the objective of a trial is to estimate an effect with a view to planning a later definitive study. This paper describes the calculations for designing studies where one wishes to adopt an estimation approach through using confidence intervals around the overall response. Calculations are given for data anticipated to take a Normal form. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
52.
Estimated associations between an outcome variable and misclassified covariates tend to be biased when the methods of estimation that ignore the classification error are applied. Available methods to account for misclassification often require the use of a validation sample (i.e. a gold standard). In practice, however, such a gold standard may be unavailable or impractical. We propose a Bayesian approach to adjust for misclassification in a binary covariate in the random effect logistic model when a gold standard is not available. This Markov Chain Monte Carlo (MCMC) approach uses two imperfect measures of a dichotomous exposure under the assumptions of conditional independence and non-differential misclassification. A simulated numerical example and a real clinical example are given to illustrate the proposed approach. Our results suggest that the estimated log odds of inpatient care and the corresponding standard deviation are much larger in our proposed method compared with the models ignoring misclassification. Ignoring misclassification produces downwardly biased estimates and underestimate uncertainty. 相似文献
53.
Professor Stephen Senn Dr Dipti Amin Professor Rosemary A. Bailey Professor Sheila M. Bird FFPH Dr Barbara Bogacka Mr Peter Colman Dr rew Garrett Professor rew Grieve Professor Sir Peter Lachmann FRS FMedSci 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2007,170(3):517-579
54.
55.
Has the image of Che Guevara lost its power to evoke radical politics in the face of pervasive commodification? The commercialization of this 1960s political icon has called into question the power of the market to shape collective memories. Meanwhile, antisystemic movements of the left continue to erect his image at protest events. In light of this contest over how Che Guevara is remembered, we investigate, using data from a survey of Spanish citizens, who is most likely to recall him. We find qualified support for the theory of generational imprinting—Che is more often recalled by those generations who saw him rise to prominence during their formative years, although prominent as a collective symbol rather than as a living person. Our results also corroborate the claim that historical figures or events are more salient for, and therefore more likely to be remembered by, some subgenerational units than others. Thus, although the younger generations are in general more likely than their elders to recall Che, he is most frequently remembered by the highly educated leftists who espouse postmaterialist and posttraditionalist values and identify more with their local regions than with the nation of Spain. These patterns suggest that, in contrast to the dire predictions of mass culture theorists, the memory of Che Guevara has become increasingly tied to markers of social, ethnic‐regional, and political identity. 相似文献
56.
57.
Lukas D. Tsitsipis 《Journal of Sociolinguistics》2004,8(4):569-594
Through the use of two central Bakhtinian concepts, authoritative and internally persuasive discourse (word), this paper examines the tension between the ideology of linguistic hegemony as a source of power in the Greek public sphere and the condition of language shift faced by the Albanian‐speaking communities of modern Greece. I argue here that a cautious application of these two notions, which are relevant to linguistic ideology, can reveal crucial aspects of two processes: that of subordination to and that of questioning of the dominant linguistic ideology by local Albanian‐speaking communities. Thus, in language shift contexts, it is possible that no simple relations obtain that place social agents in unquestionable and easily predictable positions. Such an approach proves useful for the sociolinguistic study of threatened language communities. 相似文献
58.
59.
We examine the labor-cost savings associated with privatization by comparing earnings and employment trends of public and
private sector refuse workers. Findings suggest that high union earnings for workers in the public sector are a source of
labor-cost savings in the refuse industry. Evidence on job changers does not indicate that earnings for this group of workers
are a compensating differential. Metropolitan area employment findings suggest that municipalities are less likely to use
union refuse workers in the public sector when a relatively small percentage of area residents belong to a union.
The authors thank Jacqueline Agesa, Keith Bender, Maria Crawford, and Richard Perlman for valuable suggestions. Research assistance
from Eric Blackburn is greatly appreciated. 相似文献
60.
Diagnostics for dependence within time series extremes 总被引:1,自引:0,他引:1
Anthony W. Ledford Jonathan A. Tawn 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(2):521-543
Summary. The analysis of extreme values within a stationary time series entails various assumptions concerning its long- and short-range dependence. We present a range of new diagnostic tools for assessing whether these assumptions are appropriate and for identifying structure within extreme events. These tools are based on tail characteristics of joint survivor functions but can be implemented by using existing estimation methods for extremes of univariate independent and identically distributed variables. Our diagnostic aids are illustrated through theoretical examples, simulation studies and by application to rainfall and exchange rate data. On the basis of these diagnostics we can explain characteristics that are found in the observed extreme events of these series and also gain insight into the properties of events that are more extreme than those observed. 相似文献