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   2555篇
  免费   107篇
  国内免费   1篇
  2023年   14篇
  2022年   21篇
  2021年   35篇
  2020年   53篇
  2019年   56篇
  2018年   98篇
  2017年   101篇
  2016年   118篇
  2015年   73篇
  2014年   90篇
  2013年   298篇
  2012年   148篇
  2011年   160篇
  2010年   93篇
  2009年   90篇
  2008年   133篇
  2007年   108篇
  2006年   75篇
  2005年   82篇
  2004年   77篇
  2003年   85篇
  2002年   61篇
  2001年   41篇
  2000年   51篇
  1999年   21篇
  1998年   31篇
  1997年   18篇
  1996年   19篇
  1995年   9篇
  1994年   17篇
  1992年   20篇
  1991年   15篇
  1990年   30篇
  1989年   28篇
  1988年   25篇
  1987年   13篇
  1986年   25篇
  1985年   29篇
  1984年   19篇
  1983年   17篇
  1982年   10篇
  1980年   8篇
  1979年   21篇
  1978年   8篇
  1977年   7篇
  1975年   7篇
  1974年   7篇
  1970年   9篇
  1968年   7篇
  1966年   6篇
排序方式: 共有2663条查询结果,搜索用时 15 毫秒
61.
Structuring of early reaching movements: a longitudinal study   总被引:1,自引:0,他引:1  
Reaches, performed by 5 infants, recorded at 19 weeks of age and every third week thereafter until 31 weeks of age, were studied quantitatively. Earlier findings about action units were confirmed. At all ages studied, movements were structured into phases of acceleration and deceleration. Reaching trajectories were found to be relatively straight within these units and to change direction between them. It was also found that at all ages, there was generally one dominating transport unit in each reach. The structuring of reaching movements changed in four important ways during the period studied. First, the sequential structuring became more systematic with age, with the dominating transport unit beginning the movement. Second, the duration of the transport unit became longer and covered a larger proportion of the approach. Third, the number of action units decreased with age, approaching the two-phase structure of adult reaching. Finally, reaching trajectories became straighter with age.  相似文献   
62.
One-dimensional (1-D) orientation illusions induced on a test grating by a tilted and surrounding 1-D inducing grating have a well-known angular function that exhibits both repulsion and attraction effects. Two-dimensional (2-D) orientation illusions are those induced on a test grating by 2-D image modulation, such as a pair of superimposed inducing gratings at different orientations, usually orthogonal (a plaid). Given the known angular functions induced by the plaid component gratings, two hypotheses were developed that predicted different plaid-induced illusion functions. Hypothesis 1 states that the 1-D component-induced effects simply add linearly; Hypothesis 2 states that there is an additional mechanism that responds to the virtual axes of mirror symmetry of the plaid and adds to the effect. The data of two experiments were consistent with the predictions from the second hypothesis but not the first. Possible neural substrates of mechanisms that extract axes of symmetry are discussed; it is suggested that such global symmetry axes may underlie the perceived orientation of complex shapes.  相似文献   
63.
64.
Summary In this study on Wilde's phenomenon (Wilde 1950) the two components of disparity, one of them processing displacement, and the other one apparent rotation, are analysed in terms of dependence on the disparity of the end-lines of the pattern (), and on the percentage of magnification (M) of one of the monocular patterns in relation to the other one. It was found that the component of disparity for displacement ' can be expressed as a linear regression equation '=–a+b.The component of disparity for rotation, expressed as a percentage of magnification effective for rotation (M) can be expressed as M=a–b1+b2M.It was concluded that the two components of disparity are processed through independent parallel channels, the processing of the component of disparity for displacement being the faster process, accounting for the larger part of the total disparity.  相似文献   
65.
A questionnaire was administered to 47 participants attending a workshop on nuclear energy shortly after publication of a report on a proposed nuclear fuel reprocessing plant. Supporters and opponents of the proposed development differed markedly in their estimates of its possible consequences, and of the relative importance of these consequences. They also differed in their endorsement of pro- and anti-nuclear lobbies, and the factors which they felt contributed most to the “quality of life”. Overall, pro-nuclear subjects appear to place emphasis on the economic benefits of nuclear energy, while anti-nuclear subjects appearad more concerned with social and political risks, and regraded alternative energy sources as more viable. It is concluded that an analysis of such attitudinal differences requires a consideration not only of differences in beliefs, but also of differences in belief salience.  相似文献   
66.
Four cases of brain-stem tumor were described, in which myokymias were electromyographically derived from the region of several cerebral nerves. An attempt is made to interpret the effects of twitching by reference to the electromyogram. Myokymias are a positive indication of organic brain stem damage. The use subtle techniques of electromyographic examination shows that this muscular hyperkinesis is not so infrequent a symptom as is generally believed.  相似文献   
67.
68.
69.
Zusammenfassung In zwei Experimenten wurde mit Hilfe unterschiedlicher sozialer Attitüden und Werthaltungen jeweils die Hypothese geprüft, daß sich Einstellungen nach einstellungskonträrer Agitation in Richtung dieser Agitation oder aber nicht und in Gegenrichtung zur Agitation ändern, je nachdem ob sie weniger oder mehr in allgemeineren Werthaltungen verankert sind. Im Rahmen einer um die Konzeption der Verankerung erweiterten Theorie der kognitiven Dissonanz können damit besser als bisher sogenannte Bumerang-Effekte bei Änderungen von Attitüden erklärt werden.
Summary In two experiments we tested the following hypothesis concerning social attitudes and value orientations: Attitudes will be changed after counter-attitudinal agitation in the direction of this agitation or in opposite direction depending on their degree of being anchored in general value orientations. With the theory of cognitive dissonance, supplemented by the conception of anchoring, we are now able to explain better than before the so-called boomerang-effects which appear with attitude changes.
  相似文献   
70.
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