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   32024篇
  免费   416篇
  国内免费   6篇
  32446篇
  2021年   89篇
  2020年   131篇
  2019年   175篇
  2018年   3634篇
  2017年   2979篇
  2016年   2484篇
  2015年   383篇
  2014年   307篇
  2013年   1361篇
  2012年   965篇
  2011年   2731篇
  2010年   2749篇
  2009年   1724篇
  2008年   2044篇
  2007年   2548篇
  2006年   473篇
  2005年   587篇
  2004年   526篇
  2003年   504篇
  2002年   443篇
  2001年   207篇
  2000年   254篇
  1999年   194篇
  1998年   221篇
  1997年   191篇
  1996年   184篇
  1995年   166篇
  1994年   166篇
  1993年   137篇
  1992年   156篇
  1991年   143篇
  1990年   131篇
  1989年   127篇
  1988年   129篇
  1987年   138篇
  1986年   130篇
  1985年   151篇
  1984年   153篇
  1983年   160篇
  1982年   182篇
  1981年   170篇
  1980年   157篇
  1979年   132篇
  1978年   170篇
  1977年   160篇
  1976年   154篇
  1975年   150篇
  1974年   148篇
  1973年   144篇
  1972年   111篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Within the framework of valence-instrumentality (VI) theory, a fourfold model is developed to predict the contribution which is made by one outcome of an alternative to the valence of that alternative. The proposed model uses four subjective conditional probabilities which are based on the presence and absence of an alternative, and on the occurrence and nonoccurrence of an outcome. Valence is defined as the difference between the attractiveness values of the occurrence of an alternative (or an outcome) and the nonoccurrence of an alternative (or an outcome). Also, differences between subjective probabilities replace instrumentalities. Alternative valence-instrumentality formulations are analyzed in relation to the proposed fourfold model. The proposed model can be understood as a consistent application of Vroom's model (1964, Work and motivation, New York: Wiley), while other models are judged to be relatively deficient. The fourfold model, in combination with a matrix formulation of expectancy concepts, addresses a number of criticisms of VI theory and makes possible a test of the theory within the limits of its own assumptions.  相似文献   
102.
103.
Against the background claims that a meaningful life is more likely to be the product of creation than discovery and that a meaningful life must involve both subjective satisfaction and an objective moral component, three foundations of a meaningful life are discussed. These include the quality of one's relationships, the integrative power of one's goals and projects, and the role of story or stories. Concerning the role of story, the theological challenge is to choose that story or those stories that place life in a genuinely ultimate context.  相似文献   
104.
The effects of dopaminergic depletion of the nucleus accumbens was tested in various behavioral tasks such as alternation, spatial discrimination, and reversal learning, and in an extinction paradigm in a T maze. Animals with lesions showed impairment of spontaneous alternation behavior, disturbances in the acquisition of spatial discrimination, and great difficulty in reversing previously learned habits. In the extinction phase, experimental animals are unable to adjust their behavior, and continue to choose the previously reinforced arm of the T maze. It is suggested that the nucleus accumbens plays an important role in the transition of motivation into action, and that dopamine has a facilitatory influence on the mediation of these processes.  相似文献   
105.
106.
Research is reviewed suggesting that early school age children and older adults demonstrate a similar pattern of performance deficits (relative to the performance of young adults) on memory tasks, raising the possibility that age-related changes in some common factor might account for both memory development and memory decline. It is argued here that whereas “metamemory” theory of memory development does not provide a viable theory of memory decline, Craik's (F. I. M. Craik & M. Byrd, 1982, in F. I. M. Craik & S. E. Trehub (Eds.), Aging and cognitive processes, New York: Plenum; F. I. M. Craik & E. Simon, 1980, in L. W. Poon, J. L. Fozard, L. S. Cermak, D. Arenberg, & L. W. Thompson (Eds.), New directions in memory and aging, Hillsdale, NJ: Erlbaum) attentional deficit theory of memory decline provides a viable theory of memory development as well. Evidence supporting this position is reviewed, and directions for future research are discussed.  相似文献   
107.
Two experiments investigated infants’ sensitivity to familiar size as information for the distances of objects with which they had had only brief experience. Each experiment had two phases: a familiarization phase and a test phase. During the familiarization phase, the infant played with a pair of different-sized objects for 10 min. During the test phase, a pair of objects, identical to those seen in the familiarization phase but now equal in size, were presented to the infant at a fixed distance under monocular or binocular viewing conditions. In the test phase of Experiment 1, 7-month-old infants viewing the objects monocularly showed a significant preference to reach for the object that resembled the smaller object in the familiarization phase. Seven-month-old infants in the binocular viewing condition reached equally to the two test phase objects. These results indicate that, in the monocular condition, the 7-month-olds used knowledge about the objects’ sizes, acquired during the familiarization phase, to perceive distance from the test objects’ visual angles, and that they reached preferentially for the apparently nearer object. The lack of a reaching preference in the binocular condition rules out interpretations of the results not based on the objects’ perceived distances. The results, therefore, indicate that 7-month-old infants can use memory to mediate spatial perception. The implications of this finding for the debate between direct and indirect theories of visual perception are discussed. In the test phase of Experiment 2,5-month-old infants viewing the objects monocularly showed no reaching preference. These infants, therefore, showed no evidence of sensitivity to familiar size as distance information.  相似文献   
108.
109.
An attempt was made to test the hypothesis that the Egocentricity Index (Exner, 1974), a ratio which incorporates pair and reflection responses, is related to self-esteem. Sixty criminal defendants referred for psychiatric evaluation were routinely administered the Rorschach. After all other testing was completed the subjects were asked to complete the Coopersmith Self-esteem Inventory. Results found no significant relationships between the Egocentricity Index and self-esteem as measured by the Coopersmith. It was recommended that the Egocentricity Index not be used as a measure of self-esteem until research evidence to support its use in this manner is provided.  相似文献   
110.
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