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   23834篇
  免费   432篇
  国内免费   3篇
  24269篇
  2020年   234篇
  2019年   234篇
  2018年   348篇
  2017年   391篇
  2016年   397篇
  2015年   255篇
  2014年   323篇
  2013年   1758篇
  2012年   649篇
  2011年   712篇
  2010年   436篇
  2009年   408篇
  2008年   602篇
  2007年   595篇
  2006年   530篇
  2005年   473篇
  2004年   467篇
  2003年   428篇
  2002年   489篇
  2001年   737篇
  2000年   758篇
  1999年   563篇
  1998年   265篇
  1997年   229篇
  1992年   458篇
  1991年   417篇
  1990年   451篇
  1989年   424篇
  1988年   402篇
  1987年   406篇
  1986年   414篇
  1985年   435篇
  1984年   340篇
  1983年   305篇
  1982年   244篇
  1981年   223篇
  1979年   397篇
  1978年   287篇
  1977年   256篇
  1976年   229篇
  1975年   353篇
  1974年   376篇
  1973年   365篇
  1972年   329篇
  1971年   297篇
  1970年   262篇
  1969年   326篇
  1968年   363篇
  1967年   329篇
  1966年   334篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
231.
Using a graduated scale. S was required to match with his left hand the depth of three objects of equal physical depth (or thickness) held with the right hand. While making these haptic depth judgments the objects were viewed. Due to its optical properties. one object was of greater apparent visual depth than the other two, which served as controls. The critical object was judged to be of greater haptic depth than the control objects, thus demonstrating visual capture of haptic depth. This outcome is similar to that noted previously for haptically judged direction, size, and orientation with transformed visual input.  相似文献   
232.
233.
Modifications of the intake procedure usually employed in counseling settings were adopted in order to provide students the opportunity for immediate contact with a counselor. Elimination of the waiting list, reduction in number of missed appointments, and reduction of length of counseling came about. Staff satisfaction with the new approach has been high and there would be opposition to reverting to the scheduled initial interview. Possible changes in the type of problem or clients' readiness for problem-solving were observed.  相似文献   
234.
235.
236.
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   
237.
238.
The basis of the widely held opinion that the spectral sensitivities of the mechanisms determining trichromacy must be linearly related to the spectral mixture functions is examined, and a proof from simple assumptions is stated.

It is proved also that, on the van der Velden hypothesis of independent sensitive units, a spatial or temporal summation law of the form AIn = c implies a frequency-of-seeing curve of the form Q = I—e-KIn (Q = probability of detecting a stimulus of size A and intensity I; n, c and K are constants).  相似文献   
239.
Two kinds of choice reaction time experiments are reported, both of which make use of a highly overlearned sensori-motor response. When a response is required for each stimulus presented, no increase in reaction time occurs as a function of the number of alternative stimuli available. It is proposed that the increase in choice reaction times commonly thought to accompany an increase in the number of alternative choices provided reflects the unpractised state of the responder. When a response is required for only one out of n possible stimuli, a slight but consistent increase in reaction time takes place with an increase in the number of alternatives. An analogy is drawn between the second experiment and a vigilance task and an expectancy hypothesis is invoked to explain the results.  相似文献   
240.
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