全文获取类型
收费全文 | 57332篇 |
免费 | 2090篇 |
国内免费 | 19篇 |
专业分类
59441篇 |
出版年
2018年 | 838篇 |
2017年 | 810篇 |
2016年 | 903篇 |
2015年 | 652篇 |
2014年 | 803篇 |
2013年 | 4972篇 |
2012年 | 1382篇 |
2011年 | 1462篇 |
2010年 | 960篇 |
2009年 | 909篇 |
2008年 | 1414篇 |
2007年 | 1259篇 |
2006年 | 1195篇 |
2005年 | 1024篇 |
2004年 | 1009篇 |
2003年 | 1021篇 |
2002年 | 1018篇 |
2001年 | 1685篇 |
2000年 | 1617篇 |
1999年 | 1266篇 |
1998年 | 599篇 |
1996年 | 696篇 |
1995年 | 677篇 |
1994年 | 629篇 |
1992年 | 1269篇 |
1991年 | 1152篇 |
1990年 | 1142篇 |
1989年 | 1031篇 |
1988年 | 1066篇 |
1987年 | 1007篇 |
1986年 | 1038篇 |
1985年 | 1041篇 |
1984年 | 915篇 |
1983年 | 776篇 |
1982年 | 606篇 |
1981年 | 645篇 |
1979年 | 903篇 |
1978年 | 707篇 |
1977年 | 595篇 |
1976年 | 637篇 |
1975年 | 812篇 |
1974年 | 887篇 |
1973年 | 977篇 |
1972年 | 836篇 |
1971年 | 789篇 |
1970年 | 711篇 |
1969年 | 726篇 |
1968年 | 893篇 |
1967年 | 799篇 |
1966年 | 802篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
931.
932.
933.
This paper proposes test statistics based on the likelihood ratio principle for testing equality of proportions in correlated data with additional incomplete samples. Powers of these tests are compared through Monte Carlo simulation with those of tests proposed recently by Ekbohm (based on an unbiased estimator) and Campbell (based on a Pearson-Chi-squared type statistic). Even though tests based on the maximum likelihood principle are theoretically expected to be superior to others, at least asymptotically, results from our simulations show that the gain in power could only be slight. 相似文献
934.
M. W. Bunder 《Studia Logica》1984,43(1-2):75-78
In positive logic the negation of a propositionA is defined byA X whereX is some fixed proposition. A number of standard properties of negation, includingreductio ad absurdum, can then be proved, but not the law of noncontradiction so that this forms a paraconsistent logic. Various stronger paraconsistent logics are then generated by putting in particular propositions forX. These propositions range from true through contingent to false. 相似文献
935.
The effects of tobacco smoking on responses to electrical stimulation were studied according to a Method of Limits (ML) threshold analysis and a Sensory Decision Theory (SDT) analysis. For the ML procedure, Detection Threshold (DT), Pain Threshold (PT) and Tolerance Level (TL) measures were obtained. For the SDT procedure, nonparametric estimates of capacity to discriminate between stimulus intensities (P(A)) and response criterion (B) were calculated. There was no main effect of tobacco smoking on responses to electrical stimulation. Males had consistently higher ML thresholds than females in both the NS and S condition. Males also tended to increase in DT and PT after smoking. From a comparison between the effects of smoking on ML and SDT measures it was suggested that PT is related mainly to sensory factors and TL to response factors. 相似文献
936.
Asymmetric neural control systems in human self-regulation 总被引:15,自引:0,他引:15
937.
938.
S. D. Reicher 《European journal of social psychology》1984,14(1):1-21
The paper contains a detailed study of the St. Pauls' riots of April 1980. Particular attention is paid to the limits of participation in the event and the limits of crowd action. It is argued that these limits show clear social form and cannot be explained in terms of the individualistic theories that dominate crowd psychology. Instead a model of crowd behaviour based on the social identity model is advanced to account for the observations. It is concluded that crowd behaviour is more sophisticated and creative than hitherto allowed and that the neglect of this field should be remedied. 相似文献
939.
940.