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   1917篇
  免费   68篇
  2020年   29篇
  2018年   28篇
  2017年   33篇
  2016年   41篇
  2015年   35篇
  2014年   40篇
  2013年   199篇
  2012年   79篇
  2011年   58篇
  2010年   35篇
  2009年   28篇
  2008年   57篇
  2007年   63篇
  2006年   55篇
  2005年   56篇
  2004年   51篇
  2003年   48篇
  2002年   59篇
  2001年   35篇
  2000年   24篇
  1999年   26篇
  1998年   29篇
  1997年   32篇
  1996年   35篇
  1995年   37篇
  1994年   31篇
  1993年   27篇
  1992年   27篇
  1991年   26篇
  1990年   26篇
  1989年   26篇
  1988年   17篇
  1987年   24篇
  1986年   20篇
  1985年   31篇
  1984年   35篇
  1983年   35篇
  1982年   36篇
  1981年   27篇
  1980年   37篇
  1979年   32篇
  1978年   30篇
  1977年   39篇
  1976年   40篇
  1975年   22篇
  1974年   41篇
  1973年   29篇
  1972年   14篇
  1969年   16篇
  1967年   15篇
排序方式: 共有1985条查询结果,搜索用时 15 毫秒
31.
Stimulated by publicity over lawsuits involving parents of children who had died from deprivation of medical care, this article is a survey of the beliefs of religious groups that refuse medical care on theological grounds and the legal principles designed to protect children from such abuse. Particular attention is given to whether or not child-neglect laws that carve out exceptions for spiritual healing groups are constitutional under the establishment clause of the First Amendment. Very recent cases, including some still in progress, are used for illustration.  相似文献   
32.
In two experiments, we assessed the ability of a feedback stimulus during helplessness training to reduce the performance deficits common to inescapable shock. In each experiment, four groups of rats were exposed to either escapable shock (E), inescapable shock with a feedback stimulus following shock termination (Y-FS), inescapable shock with no feedback stimulus (Y-NFS), or no shock (N). The feedback stimulus eliminated the interference effects of inescapable shock when tested with an FR-3 lever press escape task (Experiment 1) or on an FR-1 task with a 3-s delay between the response and shock termination (Experiment 2). These results suggest that stress-induced biochemical changes may mediate the interference effects seen in inescapably shocked rats.  相似文献   
33.
Finke and Pinker (1982, 1983) showed subjects an array of dots followed by an arrow in a blank field, and asked them to determine whether the arrow pointed to any of the previously seen dots. Response times were linearly related to the distance between the arrow and the nearest dot, suggesting that subjects spontaneously used an internal scanning or extrapolation process to perform the task. We replicate and extend this finding by varying the retention interval, and by employing a paradigm in which subjects’ eyes are closed and the arrows are described to them using a coordinate scheme. We also show that subjects are unable to predict the form of the data when the task simply is described to them. Results suggest that mental scanning along a straight path can be performed on images reconstructed from memory, and that it does not depend on the ongoing perception of a continuous surface, on physical eye movements, or on demand characteristics.  相似文献   
34.
The Rockefeller University, New York, New York 10021 Events such as barpresses or licks, which may occur at any time during the day, are often clustered into bouts. The internal structure of such bouts can be recorded using an AM tape recorder, running the tape recorder only while bouts are in progress, and can later be analyzed off-line on a digital computer.  相似文献   
35.
Ronald N. Giere 《Synthese》1969,20(3):371-387
A comparison of Neyman's theory of interval estimation with the corresponding subjective Bayesian theory of credible intervals shows that the Bayesian approach to the estimation of statistical parameters allows experimental procedures which, from the orthodox objective viewpoint, are clearly biased and clearly inadmissible. This demonstrated methodological difference focuses attention on the key difference in the two general theories, namely, that the orthodox theory is supposed to provide a known average frequency of successful estimates, whereas the Bayesian account provides only a coherent ordering of degrees of belief and a subsequent maximization of subjective expected utilities. To rebut the charge of allowing biased procedures, the Bayesian must attack the foundations of orthodox, objectivist methods. Two apparently popular avenues of attack are briefly considered and found wanting. The first is that orthodox methods fail to apply to the single case. The second is that orthodox methods are subject to a typical Humean regress. The conclusion is that orthodox objectivist methods remain viable in the face of the subjective Bayesian alternative — at least with respect to the problem of statistical estimation.  相似文献   
36.
Speed of sorting decks of 32 cards with two alternative stimuli was measured. The stimuli were pairs of dots with attributes of distance between dots, angle of orientation of the pair, and position of the pair to the right or left of center. The attributes varied in relative discriminability and were used in all possible pair- and triple-correlated (redundant) combinations. Results showed an increase in speed of sorting with either an increase in discriminability or an increase in number of redundant attributes. It is argued that the increased speed with addition of redundant attributes is due both to a selective serial processing of attributes (requiring attribute separability) and to an increased discriminability with combined attributes (requiring attribute integrality).  相似文献   
37.
Services of rehabilitation agencies and facilities tend to be structured to the needs of the larger American culture. It is important, however, to reconsider our social service programs in view of the needs of different cultural groups when providing services that will aid these individuals to move across cultural boundaries. An attempt is made in this paper to develop a model of the individual who undergoes such cultural transition. Such a model should help define problems in service programs, assess the value of current service activities, and identify areas for developing new services that will aid the overall process of cultural transition. A model of behavior development is outlined, followed by a formulation of a model of the individual in cultural change.  相似文献   
38.
It has been observed that the number of different ways in which a graph withp points can be labelled isp! divided by the number of symmetries, and that this holds regardless of the species of structure at hand. In this note, a simple group-theoretic proof is provided.This work was supported by Grant MH 10834 from the National Institute of Mental Health.  相似文献   
39.
Judgments were made of the size of a small, luminous (inner) square appearing in the center of a somewhat larger, variable (outer) square, the whole pattern appearing in the dark. Accuracy of judgment was greatest when the outer square was constant from trial to trial but deteriorated when the outer square also varied in size, reaching a lower limit less than the accuracy produced under the absolute judgment condition (no outer square presented). An application of multiple discriminant analysis and the use of a maximum likelihood observer model provided estimates of the extent to which Os responded to inner and outer size variation as separate aspects of stimulation. Although Os differed markedly in this respect, their ability to identify inner square size under the various conditions did not reflect this difference.  相似文献   
40.
A sea lion under water performed virtually without errors on a series of three form-discrimination reversals. Significant training requirements were the combining of a previously well-established size cue preference with the nonpreferred form cue, followed by the gradual reduction of the size cue until it was completely eliminated. Orienting responses reached a peak and then decreased during progressive-dimensional-change training, suggesting critical stages in the transition of attention from the size dimension to the form dimension. Further experimentation revealed that intensive training during these critical stages obviated the need to reduce very gradually the size cue. Without special training sea lions make perseverative errors on a series of form-discrimination reversals. "Emotional" or nontest-oriented behavior was associated only with the occurrence of successive errors.  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