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   57392篇
  免费   1562篇
  国内免费   29篇
  2020年   415篇
  2019年   517篇
  2018年   4008篇
  2017年   3350篇
  2016年   2928篇
  2015年   713篇
  2014年   704篇
  2013年   3172篇
  2012年   1758篇
  2011年   3501篇
  2010年   3145篇
  2009年   2290篇
  2008年   2714篇
  2007年   3203篇
  2006年   1027篇
  2005年   1097篇
  2004年   1025篇
  2003年   958篇
  2002年   917篇
  2001年   1184篇
  2000年   1194篇
  1999年   905篇
  1998年   435篇
  1997年   422篇
  1996年   395篇
  1995年   422篇
  1993年   393篇
  1992年   718篇
  1991年   668篇
  1990年   639篇
  1989年   616篇
  1988年   614篇
  1987年   566篇
  1986年   555篇
  1985年   613篇
  1984年   536篇
  1983年   509篇
  1982年   407篇
  1979年   573篇
  1978年   430篇
  1977年   398篇
  1976年   423篇
  1975年   440篇
  1974年   518篇
  1973年   533篇
  1972年   453篇
  1971年   381篇
  1968年   455篇
  1967年   398篇
  1966年   374篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Averaged responses of the occipital lobes to flashes imposed along the midline of the upper part of the retina are larger and of shorter latency than responses to flashes imposed on the lower retina. Since reaction times also are shorter when the upper retina is stimulated, this study provides further evidence for the generalization that reaction time varies inversely with amplitude and directly with latency of the evoked response.  相似文献   
952.
Three different coding schemes, i.e., transformations between stimuli and responses, were used in a continuous information transmission situation. The stimuli were groups of binary digits and S was required to transform these into verbal equivalents of combinations formed by taking various sets of the English letters. Three codes, one based on communication theory, one based on Miller’s (1956) chunking hypothesis, and a combination of the first two were used. In addition, two levels of stimulus redundancy, zero and 0.5 were used. Time to complete the task and errors were the de-pendent variables. The Ss were run for twelve days. The basic result was that Ss transmitted information at a constant rate regardless of the code or redundancy level used.  相似文献   
953.
If S. S. Stevens’ exponents indicate the rates at which sensations grow with increases in sensory intensity, they ought to correlate with the population norms of top sensory magnitudes. Using a comprehensive sample of eight sensory dimensions, the tau coefficient of rank correlation between Stevens’ exponents and the medians of the top sensory magnitudes reported by 305 observers was found to be only +.15 (p>05). With the geometric means tau fell to ?.04. A split-half consistency check on the medians of the population norms suggested that they were not to blame for the low correlation. Direct comparisons of pairs of sensory dimensions on 146 additional observers produced results which confirmed the population norms. Since there is no way of comparing most of the top physical stimuli experienced in everyday life, it is not possible to make a joint prediction from exponents and top stimuli. S. S. Stevens’ exponents thus appear to have little predictive value outside the experimental conditions under which they were measured.  相似文献   
954.
An experiment was performed which demonstrated a preference in hooded rats for vertical rather than horizontal striatums. It was demonstrated that experience in discriminating between horizontal and vertical striations facilitates subsequent discrimination between squares and circles, regardless of which type of striation was positive in initial training. This finding has implications for theories of shape recognition, which are discussed.  相似文献   
955.
956.
957.
958.
959.
Two recent experiments (Moray, 1959; Oswald, Taylor and Treisman, 1960) have shown that in dichotic listening, and in sleep one's own name seems to be responded to selectively. We have shown for 10 subjects, each listening binaurally to the same recording of a list of their names repeated at random 10 times, and masked by noise, that the subject's own name had a significantly lower threshold than other names. The effect we found was not significantly different from the one found by Oswald et al. during sleep and by Moray for the dichotic situation.

These three experiments taken together suggest that the same pattern-analysing mechanism is involved in normal listening, dichotic listening to the rejected message, and in discrimination during sleep.  相似文献   
960.
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