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   53925篇
  免费   2201篇
  国内免费   33篇
  56159篇
  2019年   650篇
  2018年   931篇
  2017年   908篇
  2016年   997篇
  2015年   677篇
  2014年   847篇
  2013年   4122篇
  2012年   1565篇
  2011年   1581篇
  2010年   1009篇
  2009年   1030篇
  2008年   1452篇
  2007年   1404篇
  2006年   1277篇
  2005年   1093篇
  2004年   1084篇
  2003年   1031篇
  2002年   1067篇
  2001年   1619篇
  2000年   1596篇
  1999年   1236篇
  1998年   562篇
  1997年   547篇
  1996年   536篇
  1995年   543篇
  1992年   1060篇
  1991年   980篇
  1990年   948篇
  1989年   907篇
  1988年   909篇
  1987年   832篇
  1986年   893篇
  1985年   907篇
  1984年   768篇
  1983年   705篇
  1982年   545篇
  1979年   837篇
  1978年   647篇
  1977年   576篇
  1976年   596篇
  1975年   673篇
  1974年   820篇
  1973年   882篇
  1972年   708篇
  1971年   674篇
  1970年   611篇
  1969年   656篇
  1968年   819篇
  1967年   735篇
  1966年   724篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
211.
212.
213.
214.
Ratings of pre-morbid intelligence level, derived from the hospital charts of 26 chronic schizophrenics, were correlated with the post-mortem brain volume measures of cortex, white matter, central grey matter, and ventricles. Contrary to hypothesis, no significant correlations were found.  相似文献   
215.
INFLUENCES ON MANAGERIAL PAY ALLOCATIONS: A DEPENDENCY PERSPECTIVE   总被引:1,自引:0,他引:1  
This paper reviews evidence and presents arguments for the view that managerial pay allocations are influenced by the degree of dependence on subordinates and by threats to that dependence. In assessing this view, the issues of managerial discretion in pay allocation and pay as a means of managing dependencies are explored. Major sources of objective and subjective dependence on subordinates are identified. Predictions are made regarding managerial pay allocations under various conditions of dependence and dependency threat. Finally, research and practical implications of the dependency perspective are discussed.  相似文献   
216.
217.
M. W. Bunder 《Studia Logica》1988,47(2):129-143
In the early thirties, Church developed predicate calculus within a system based on lambda calculus. Rosser and Kleene developed Arithmetic within this system, but using a Godelization technique showed the system to be inconsistent.Alternative systems to that of Church have been developed, but so far more complex definitions of the natural numbers have had to be used. The present paper based on a system of illative combinatory logic developed previously by the author, does allow the use of the Church numerals. Given a new definition of equality all the Peano-type axioms of Mendelson except one can be derived. A rather weak extra axiom allows the proof of the remaining Peano axiom. Note. The illative combinatory logic used in this paper is similar to the logic employed in computer languages such as ML.The author wishes to thank Dr. Roger Hindley for proofreading this paper and for making some useful suggestions. This paper was presented at the 1986 Annual Conference of the Australasian Association of Logic in Auckland, 9–12 July, 1986.  相似文献   
218.
Perception of translational heading from optical flow   总被引:3,自引:0,他引:3  
Radial patterns of optical flow produced by observer translation could be used to perceive the direction of self-movement during locomotion, and a number of formal analyses of such patterns have recently appeared. However, there is comparatively little empirical research on the perception of heading from optical flow, and what data there are indicate surprisingly poor performance, with heading errors on the order of 5 degrees-10 degrees. We examined heading judgments during translation parallel, perpendicular, and at oblique angles to a random-dot plane, varying observer speed and dot density. Using a discrimination task, we found that heading accuracy improved by an order of magnitude, with 75%-correct thresholds of 0.66 degrees in the highest speed and density condition and 1.2 degrees generally. Performance remained high with displays of 63-10 dots, but it dropped significantly with only 2 dots; there was no consistent speed effect and no effect of angle of approach to the surface. The results are inconsistent with theories based on the local focus of outflow, local motion parallax, multiple fixations, differential motion parallax, and the local maximum of divergence. But they are consistent with Gibson's (1950) original global radial outflow hypothesis for perception of heading during translation.  相似文献   
219.
Cerebral hemispheric mechanisms in the retrieval of ambiguous word meanings   总被引:10,自引:6,他引:4  
Targets related to ambiguous primes were projected to the left and right visual fields in a lexical priming experiment with stimulus onset asynchronies (SOA) of 35 and 750 msec. Right visual field results were similar to our earlier results with central projection (G. B. Simpson & C. Burgess, 1985, Journal of Experimental Psychology: Human Perception and Performance, 11, 28-39). Facilitation was found for the more frequent meaning at both SOAs and a decrease in facilitation for the less frequent meaning at the longer SOA. In contrast, left visual field results indicated a decay of facilitation for the more frequent meaning at the longer SOA, while activation for the subordinate meaning increased. Results suggest that, while automatic processing occurs in both hemispheres, only the left hemisphere engages in controlled processing of ambiguous word meanings. In addition, the present results support the idea that the right hemisphere has a special role in ambiguity resolution and that the right hemisphere lexicon possesses a richer endowment than earlier thought.  相似文献   
220.
In choice reaction time, stimuli and responses in some combinations (e.g., based on spatial arrangement) are faster than in other combinations. To test whether motion toward a position yields faster responses at that position, a computer-generated square in front of one hand appeared to move either toward that hand or toward the other hand. Compatible responses (e.g., motion toward left hand/left response) were faster than incompatible responses, even when that opposed traditional positional compatibility. In Experiment 2, subjects responded to the same stimuli but with both hands left, right, or on the body midline. Medial responses were the fastest, showing that destination, rather than mere relative position, was a critical variable. It was suggested that spatial compatibility effects are not unique to position but apply to a variety of task situations, describable by J.J. Gibson's theory of affordances, in which he claims that one perceives the actions (e.g., catching) permitted in a situation.  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