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   19918篇
  免费   882篇
  国内免费   4篇
  2021年   178篇
  2020年   241篇
  2019年   350篇
  2018年   455篇
  2017年   434篇
  2016年   444篇
  2015年   304篇
  2014年   417篇
  2013年   1704篇
  2012年   673篇
  2011年   721篇
  2010年   407篇
  2009年   441篇
  2008年   589篇
  2007年   611篇
  2006年   544篇
  2005年   464篇
  2004年   481篇
  2003年   407篇
  2002年   427篇
  2001年   497篇
  2000年   552篇
  1999年   382篇
  1998年   236篇
  1997年   179篇
  1996年   186篇
  1995年   184篇
  1992年   302篇
  1991年   305篇
  1990年   315篇
  1989年   296篇
  1988年   286篇
  1987年   252篇
  1986年   260篇
  1985年   284篇
  1984年   219篇
  1983年   222篇
  1982年   179篇
  1980年   175篇
  1979年   263篇
  1978年   234篇
  1975年   233篇
  1974年   256篇
  1973年   282篇
  1972年   232篇
  1971年   221篇
  1969年   200篇
  1968年   264篇
  1967年   254篇
  1966年   215篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
Pairs of high-school students matched-to-sample for money. On each trial, the first pair member to complete a fixed ratio of knob-pulling responses could work the matching problem on that trial. Competition occurred when both pair members responded for the problem. Sharing occurred when only one pair member responded on each trial, and the subjects alternated trials. Hence, sharing requires less responding and still allows a moderate number of reinforcers for each subject. Recent research has shown that increasing the response requirement to the point that it may have aversive properties will produce a change from competition to sharing. A related variable is an adjusting schedule that adjusts the subjects' response requirements so that their abilities to take reinforcers are equal. In this way, subjects might learn that competition requires more responding but produces no more reinforcers. However, recent research also suggests that competition decreases over sessions without experimental manipulations. Because of this possibility of a time-related variable, ratio size and an adjusting schedule were studied in a group design. Competition did decrease for all groups over sessions, but the large-ratio groups switched from competition to sharing sooner than the low-ratio groups. The adjusting schedule had a similar but smaller effect.  相似文献   
942.
Two experiments employing the release from PI method were conducted to determine whether degree of release could be predicted by the amount of denotative attribute overlap between the control and experimental groups. This theory was very appropriate for predicting the results of the first experiment, but was less successful in the second unless a connotative attribute is also introduced. It is suggested that this class of attribute should be included in semantic memory conceptualization.  相似文献   
943.
Two experiments examined the role of information storage and frequency estimation processes in a simple decision task. On each trial from one to five simultaneous sequences of information were presented, and subjects were required to monitor and respond to each sequence. In one study independent groups of subjects gave decisions, recognition responses. or frequency judgments. In a second study recall responses were obtained from subjects as part of the decision and frequency judgment tasks. Changes in performance as the number of simultaneous sequences increased suggested an independence of decisions from memory for specific information. Performance on the decision and frequency judgment tasks exceeded at times that which was possible on the basis of specific information available. Other data suggested that subjects in the frequency estimation tasks maintained an accurate frequency count when possible, but in the decision task kept little more than a record of their currently favored hypothesis. When direct counting was prevented in the second experiment. performance in the two tasks was not significantly different, suggesting that the two processes are very similar under such conditions.  相似文献   
944.
Four groups of human subjects were given 360 classical eyeblink conditioning trials. All groups received the same UCS (unconditioned stimulus) intensity on[Formula: see text] (nonconditioned response) trials but differed in the intensity presented on CR trials. Response probability increased as a positive function of UCS intensity on CR trials. Phase 1 of the two-phase model was longer when no UCS was presented on CR trials, but did not differ in duration among the remaining three groups. Most subjects could be described with a single operator in Phase 2, the operator limit increasing as a positive function of CR-contingent UCS intensity. For subjects requiring different operator limits on CR and[Formula: see text] trials, the latter was lower with high CR-trial intensities but higher with low CR-trialintensities. The results were interpreted to be more consistent with drive theory than with "law-of-effect" or two-factor theories.  相似文献   
945.
946.
This study was designed to test the effects of both interaction distance and the quality of the interaction upon attraction. It was found that close interaction distances amplified the quality of the interaction so that for a positive interaction there was more liking for a close rather than a far partner, while for a negative interaction a close partner was liked less. The implications of this finding for research concerning crowding is discussed, as are possible explanatory mechanisms.  相似文献   
947.
Self-awareness was either manipulated by a mirror (experimental) or not (control). Subjects were selected for being high or low in private self-consciousness (disposition to attend to one's thoughts, feelings, motives). Private self-consciousness had a stronger effect on self-attributions than did self-awareness. These findings have implications for attribution, self-consciousness, and the relationship between manipulations and dispositions.  相似文献   
948.
The sensitivity of the scalp-recorded, auditory evoked potential to selective attention was examined while subjects monitored one of two dichotically presented speech passages for content. Evoked potentials were elicited to irrelevant probe stimuli (vowel sounds) embedded in both the right- and the leftear’s message. The amplitude of the evoked potential was larger to probe stimuli embedded in the attended message than to probe stimuli in the unattended message. Recall performance was unaffected by the presence of the probes. The results are interpreted as supporting the hypothesis that this evoked potential sensitivity reflects an initial “input selection” stage of attention.  相似文献   
949.
Data consisting of 79 cognitive measures from Project TALENT for 100,000 white and black high school students have been analyzed for possible race by sex interactions. Control variables included geographical area, grade in high school, and socio-economic class. Race by sex interactions are largest when socioeconomic class is controlled and are highly related to the size of the main effect of sex as well. White boys and girls differ more than black boys and girls whether the overall sex difference favors males or females. Sex by grade and, to a lesser extent, sex by area interactions were also moderately large and consistent with the size of the main effect of sex. Since there are no consistent relationships with other main effects, and since the measures producing sex differences also tend to produce the interactions, it is concluded that sex differences and the interactions with sex share the same causes. Differences between these results and those of Jensen are also discussed.  相似文献   
950.
In four experiments, subjects read 100-word passages and circled instances of the letter t. Subjects missed a disproportionate number of ts in the word the. Evidence was provided against explanations of this effect involving the location and pronunciation of the t in the and against an explanation in terms of the redundancy of the. Rather the high frequency of the appeared to be critical, and it was suggested that high-frequency words are read in terms of units larger than the letter.  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