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   36989篇
  免费   1358篇
  国内免费   11篇
  2019年   388篇
  2018年   566篇
  2017年   517篇
  2016年   613篇
  2015年   439篇
  2014年   523篇
  2013年   3489篇
  2012年   903篇
  2011年   933篇
  2010年   602篇
  2009年   591篇
  2008年   897篇
  2007年   812篇
  2006年   756篇
  2005年   635篇
  2004年   612篇
  2003年   651篇
  2002年   621篇
  2001年   1180篇
  2000年   1131篇
  1999年   877篇
  1996年   499篇
  1995年   476篇
  1994年   464篇
  1993年   435篇
  1992年   909篇
  1991年   804篇
  1990年   807篇
  1989年   712篇
  1988年   715篇
  1987年   692篇
  1986年   694篇
  1985年   680篇
  1984年   607篇
  1983年   501篇
  1982年   401篇
  1981年   414篇
  1980年   389篇
  1979年   569篇
  1978年   435篇
  1975年   532篇
  1974年   518篇
  1973年   587篇
  1972年   558篇
  1971年   497篇
  1970年   440篇
  1969年   422篇
  1968年   534篇
  1967年   454篇
  1966年   442篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
Tachistoscopic presentation of light flashes was used to test for differences in visual sensitivity among 3 groups of practitioners of Buddhist mindfulness meditation and non-meditator-controls. Meditation practitioners were able to detect light flashes of shorter duration than the non-meditators. There were no differences among the meditator groups. There were no differences among the groups in ability to discriminate between closely spaced successive light flashes. The lower detection threshold for single light flashes for the meditators may reflect an enduring increase in sensitivity, perhaps the long-term effects of the practice of mindfulness meditation on certain perceptual habit patterns. The lack of significant differences in the discrimination of successive light flashes probably reflects the resistance of other perceptual habit patterns to modification. The results support the statements found in Buddhist texts on meditation concerning the changes in perception encountered during the practice of mindfulness.  相似文献   
922.
923.
924.
The idea of a psychopathology of fate or what had come to be called a fate neurosis has failed to retain any established place in the structure of psychoanalytic thought. The clinical observations and theoretical formulations, to which the idea of a fate neurosis answered, have been subsumed in the course of things by more fundamental and systematic conceptualizations. A review of Helene Deutsch's (1930) paper, "Hysterical Fate Neurosis," is therefore bound to be largely an excursion into an area of intellectual history. However, such history never fails to shed light on certain ongoing clinical and theoretical problems that may have lost too much to current developments in psychoanalytic thought. It is with this historical purpose that the present study of Deutsch's classic paper on a fate neurosis is undertaken.  相似文献   
925.
Distraction and coping with pain   总被引:7,自引:0,他引:7  
  相似文献   
926.
The question of left hemisphere dysfunction in infantile autism   总被引:3,自引:0,他引:3  
  相似文献   
927.
Is there a cell-biological alphabet for simple forms of learning?   总被引:5,自引:0,他引:5  
  相似文献   
928.
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   
929.
Neil Tennant 《Studia Logica》1984,43(1-2):181-200
This paper treats entailment as a subrelation of classical consequence and deducibility. Working with a Gentzen set-sequent system, we define an entailment as a substitution instance of a valid sequent all of whose premisses and conclusions are necessary for its classical validity. We also define a sequent Proof as one in which there are no applications of cut or dilution. The main result is that the entailments are exactly the Provable sequents. There are several important corollaries. Every unsatisfiable set is Provably inconsistent. Every logical consequence of a satisfiable set is Provable therefrom. Thus our system is adequate for ordinary mathematical practice. Moreover, transitivity of Proof fails upon accumulation of Proofs only when the newly combined premisses are inconsistent anyway, or the conclusion is a logical truth. In either case Proofs that show this can be effectively determined from the Proofs given. Thus transitivity fails where it least matters — arguably, where it ought to fail! We show also that entailments hold by virtue of logical form insufficient either to render the premisses inconsistent or to render the conclusion logically true. The Lewis paradoxes are not Provable. Our system is distinct from Anderson and Belnap's system of first degree entailments, and Johansson's minimal logic. Although the Curry set paradox is still Provable within naive set theory, our system offers the prospect of a more sensitive paraconsistent reconstruction of mathematics. It may also find applications within the logic of knowledge and belief.  相似文献   
930.
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   
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