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   25062篇
  免费   269篇
  国内免费   4篇
  2023年   62篇
  2022年   86篇
  2021年   105篇
  2020年   144篇
  2019年   137篇
  2018年   3640篇
  2017年   2965篇
  2016年   2409篇
  2015年   327篇
  2014年   236篇
  2013年   764篇
  2012年   934篇
  2011年   2715篇
  2010年   2707篇
  2009年   1596篇
  2008年   1961篇
  2007年   2375篇
  2006年   246篇
  2005年   411篇
  2004年   278篇
  2003年   238篇
  2002年   180篇
  2001年   85篇
  2000年   127篇
  1999年   59篇
  1998年   46篇
  1997年   34篇
  1996年   29篇
  1995年   19篇
  1994年   14篇
  1993年   16篇
  1992年   30篇
  1991年   20篇
  1990年   31篇
  1989年   23篇
  1988年   27篇
  1987年   16篇
  1985年   12篇
  1984年   16篇
  1983年   12篇
  1979年   15篇
  1978年   11篇
  1976年   15篇
  1974年   10篇
  1971年   10篇
  1970年   10篇
  1969年   10篇
  1968年   11篇
  1966年   9篇
  1965年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
An invisible displacement test was administered to cats in order to test the hypothesis that search behaviour in this species is influenced by their limited capacity for object permanence as well as by their previous experience with the environment. Experiment 1 compared three groups of cats in a five-choice hiding task in which the hiding places could be discriminated by their spatial positions. Two groups received a visible displacement training before the invisible displacement test and one group did not. Experiment 2 compared two groups of trained subjects in the same task, but the hiding places could be discriminated by spatial and visual cues. The results confirmed that cats are unable to solve problems with invisible displacements. The visible displacement training improved their performance, but was not sufficient to make them succeed. Experience with the hiding potential of the covers also gives more persistence to search behaviour. Finally, the distribution of search attempts is not determined by the proximity to the target and is influenced only partially by the subjects' previous experience. Like Stage 5 infants, cats rely mainly on their immediate perception. They search for an object in the last location they have seen it disappear or under the nearest cover from this location.  相似文献   
63.
The essay examines the argument advanced by E.D. Hirsch, Jr., for instituting ‘cultural literacy’ as a fundamental priority of schools. A number of confusions and equivocations in Hirsch's reasoning are identified, and the propensity of his project to indoctrinate is exposed. Among the features of Hirsch's argument shown to be troubling are his shifting construal of ‘language’, his inconsistency about the requirements of cultural literacy, and his uncritical relation to traditional images of the American past and present. The upshot is to raise the question why Hirsch's project has elicited wide support and praise.  相似文献   
64.
Tested a 7-month, media-based, community intervention among Hispanics in San Francisco designed to change levels of information on the damaging effects of cigarette smoking and on the availability of culturally appropriate cessation services. Three community-wide surveys of Hispanics were conducted with independent random samples, two as baselines (n = 1,660 and 2,053) and one postintervention (n = 1,965). Results showed that changes in the level of awareness of cessation services had taken place after implementation of the intervention. Furthermore, those changes took place primarily among the less acculturated Spanish-speaking Hispanics who were the target of the intervention. The changes in information reported here demonstrate that a culturally appropriate information dissemination campaign that utilizes multiple channels can produce changes in a community's level of information even when the campaign is implemented for a relatively short period.  相似文献   
65.
How is meaning assigned to those terms in a theory which are remote from direct observational instantiation? Models and analogies play a role, but close examination of theories in high energy physics shows that the design of experimental apparatus also influences the interpretation of such terms. Certain apparatus favours certain kinds of effects, and this affects the way mathematical theories are interpreted. In particular track producing apparatus becomes involved with theories in which photonic terms are picked out in the theory. A further conceptual constraint is thus introduced. It is argued that this situation favours the interpretation of dispositional properties as affordances rather than as simple dispositions.  相似文献   
66.
The role accorded to the public by scientists and philosophers of science has undergone an essential historical change in the last three centuries. Public participation in (witnessing of) scientific experiments was considered an important requirement for 17th century experimenters (e.g. for Boyle or Pascal). The cognitive role played by lay persons was later substantially downgraded; witnessing went out of fashion, while science became more and more esoteric and a matter for experts only. Part of this process was that all scientific disciplines became intensively compartmentalized and in consequence a rather puzzling or even paradoxical situation appeared: that the scientists themselves were and are being reduced epistemically to the status of lay persons, outside of their proper field of expertise (as was pointed out by J. Hardwig). The paper deals with some cognitive aspects of this historical process.  相似文献   
67.
68.
69.
How can we explain that an assertion on something perceived can be understood in the same manner by somebody who cannot perceive that scene? This problem bases the interest in computational linguistics in how listener modeling could possibly be harmonized with reference semantics. Mental images substituting real perception appear as a way out. The architecture of the listener model has to be adapted to the creation and use of such pictorial data structures. Furthermore, the relation between the latter and a verbal (i. e., propositional) representation must be understood. The resulting architecture of a listener model with reference semantics can be employed to solve communicational problems from three general classes in a better way, as is demonstrated by an example implementation.  相似文献   
70.
La présente étude vise à examiner la nature des liens entre les styles d'attachement (sécurisant, anxieux/ambivalent et évitant), la solitude et la détresse psychologique (dépression, anxiété, agressivité et problèmes cognitifs) chez des jeunes adultes. L'échantillon se compose de 407 étudiants de niveau collégial dont l'âge moyen se situe à 18 ans. Les sujets doivent répondre à deux questionnaires d'évaluation du style d'attachement, à l'échelle de solitude UCLA, ainsi qu'à l'index de symptômes psychiatriques. Les résultats laissent voir que les individus ayant un style d'attachement sécurisant rapportent moins de symptômes de dépression et de sentiments de solitude que les sujets des styles anxieux/ambivalent et évitant. De même, ils vivent moins d'anxiété, d'agressivité et de problèmes cognitifs que les individus du style anxieux/ambivalent. Par ailleurs, les individus du style d'attachement anxieux/ambivalent sont plus déprimés, anxieux et agressifs que les individus du style évitant. Par contre, aucune différence significative ne ressort entre les sujets des styles d'attachement anxieux/ambivalent et évitant sur le plan des problèmes cognitifs et de la solitude. Des analyses de régression multiple montrent que l'attachement anxieux/ambivalent et la solitude expliquent un pourcentage significatif de la variance associée à la détresse psychologique. Enfin, il ressort que la solitude joue un rôle modérateur dans la relation unissant l'attachement non sécurisant et les problèmes de nature cognitive, alors qu'elle joue un rôle médiateur dans la relation entre l'attachement sécurisant, la dépression et l'anxiété.  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