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   59490篇
  免费   1692篇
  国内免费   14篇
  2020年   419篇
  2019年   482篇
  2018年   3980篇
  2017年   3307篇
  2016年   2881篇
  2015年   733篇
  2014年   699篇
  2013年   2810篇
  2012年   1711篇
  2011年   3445篇
  2010年   3131篇
  2009年   2106篇
  2008年   2630篇
  2007年   3093篇
  2006年   874篇
  2005年   1038篇
  2004年   927篇
  2003年   811篇
  2002年   760篇
  2001年   1295篇
  2000年   1274篇
  1999年   905篇
  1998年   416篇
  1997年   359篇
  1992年   861篇
  1991年   800篇
  1990年   828篇
  1989年   713篇
  1988年   712篇
  1987年   682篇
  1986年   714篇
  1985年   787篇
  1984年   589篇
  1983年   545篇
  1982年   366篇
  1981年   357篇
  1979年   686篇
  1978年   424篇
  1977年   415篇
  1976年   413篇
  1975年   583篇
  1974年   668篇
  1973年   713篇
  1972年   617篇
  1971年   578篇
  1970年   573篇
  1969年   562篇
  1968年   751篇
  1967年   664篇
  1966年   595篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
An ann-out-of-water response was conditioned as an operant inOctopus cyaneus Gray. The response was limited to a vertical tube, 2.54 em i.d, Photoresistive sensors, illuminated with modulated light arranged around the tube above the waterline, detect the presence of an opaque object in the tube. The signal from this response detector is amplified and used to initiate a commercial motor-driven universal feeder according to the reinforcement schedule maintained by the logic control circuit. A sample cumulative record for perfonnance on a CRF schedule is given.  相似文献   
962.
A circuit to permit an electronic drinkometer to operate during footshock is described. The circuit employs a diode matrix that allows all grid bars to be connected at one point to form one electrode of the drinkometer; it is isolated at another point so as not to shortcircuit the impressed footshock.  相似文献   
963.
This, then, is a very personal and informal view of some of the peculiar trends of computer application in experimental psychology. If there is any single point on which I would prefer to end, it would be a reiteration of my belief that, on the whole, the positive attributes and contributions to our science of on-line computers have far outweighed some of these nagging aggravations. Regardless of what has been done and in what way it has been done, it is certainly better to have done something than never to have done anything at all. Our science, like a computer program, is also contingent and self-adapting, and most minor strategic errors are quickly corrected. But no one can debug a computer program or a major technological movement without at least having pushed the startbutton.  相似文献   
964.
Errors in a serial choice-reaction time experiment employing two-finger chord responses to alphabetic stimuli are shown to be distributed in a significantly non-random fashion. Two factors are postulated which are relevant to prediction of the error response. These are the presence or absence of a common finger, and the difference in finger separation, between the actual and the required response. It is suggested that the chord response is coded in terms of a pattern (the distance between the two response components). Responses which mirror the correct response about the centre of the hand are also shown to be significantly more frequent.  相似文献   
965.
Overextinction of the GSR component of the orienting response was examined in a sample of 68 socially disturbed adolescents. Continued stimulus repetition beyond the point of habituation resulted in GSR return after 50–60 stimulus presentations. However, division of Ss into sleep and non-sleep groups using behavioral and self-report criteria, failed to support Sokolov’s (1963) notion that overextinction is accompanied by drowsiness. A possible explanation of these results is discussed.  相似文献   
966.
967.
Differential vocal emphasis in the tape-recorded instruction reading for a standard person perception task was manipulated by mechanically raising or lowering the volume of the key words describing the success or failure response alternatives on the rating scale. In a series of three experiments, Ss exposed to success emphasis in the instructions rated the stimulus persons as more successful than did Ss exposed to failure emphasis. This trend was reversed for Ss who listened twice to the instructions. None of the Ss reported awareness of the influence attempt.  相似文献   
968.
Two hundred and fifty-two brightness functions for seven simultaneously presented black, gray, and white squares on black, gray, and white backgrounds approximated power curves with positive exponents when illuminance was varied in seven steps over 1.9 log fL. Mean exponents were significantly larger for whiter vs blacker squares and for squares on the white vs the gray background. Mean exponents also increased more for squares on white than on black or gray backgrounds. Finally, a white replacing a black background elicited increasingly larger décrémentai responses as the squares varied from black to white. Jameson and Hurvich’s opponent-process theory, tested by the experiment, was not predictive.  相似文献   
969.
This experiment represented an initial at tempt at comparing same-different classifications and similarity judgments of Markov histoforms sampled from three different schema families. A measure of individual stimulus variability was more strongfy related to classification responses than to judged similarity. Dichotomous responses, derived from the similarity data by imposing threshold criteria, were found to be highly similor to real classification responses when the threshold values were estimated directly from the latter; little correspondence, however, was obtained using optimal classification criteria. The results support the notion that somewhat different features are used in making classification responses and similarity judgments, and indicate the need for developing more sensitive tasks involving controlled scanning of pattem information.  相似文献   
970.
Intermodal perceptual equivaience was investigated, using visual and tactual oddity discrimination and cross-modal matching-to-sample tasks. Four groups of Ss were presented with 100 problems made up of randomly derived forms from five levels of sidedness. The same quadratic relationship was observed for all tasks as a function of complexity, with optimal performance at eight sides. Comman information utilization, as indicated by intercorrelations of performance variables and by correlational analyses with differences in form measures, was not as pronounced within side classes. Evidence concerning the nature of pattern-feature usage in discrimination was obtained from graphical analyses.  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