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   51743篇
  免费   2144篇
  国内免费   19篇
  2020年   533篇
  2019年   641篇
  2018年   917篇
  2017年   905篇
  2016年   925篇
  2015年   634篇
  2014年   845篇
  2013年   3792篇
  2012年   1514篇
  2011年   1639篇
  2010年   933篇
  2009年   1004篇
  2008年   1422篇
  2007年   1412篇
  2006年   1323篇
  2005年   1156篇
  2004年   1143篇
  2003年   1062篇
  2002年   1068篇
  2001年   1679篇
  2000年   1592篇
  1999年   1222篇
  1998年   597篇
  1997年   507篇
  1992年   974篇
  1991年   909篇
  1990年   942篇
  1989年   891篇
  1988年   867篇
  1987年   810篇
  1986年   850篇
  1985年   944篇
  1984年   750篇
  1983年   683篇
  1982年   549篇
  1981年   512篇
  1979年   798篇
  1978年   599篇
  1977年   492篇
  1976年   525篇
  1975年   696篇
  1974年   792篇
  1973年   821篇
  1972年   646篇
  1971年   590篇
  1970年   561篇
  1969年   599篇
  1968年   740篇
  1967年   643篇
  1966年   656篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
32.
33.
34.
35.
Brain mapping studies using dynamic imaging methods demonstrate areas regional cerebral blood flow (rCBF) decreases, as well as areas where increases, during performance of various experimental tasks. Task holds for both sets of cerebral blood flow changes (CBF), providing the opportunity to investigate areas that become and “activated” in the experimental condition relative to control state. Such data yield the intriguing observation that in areas in emotional processing, such as the amygdala, the posteromedial cortex, and the ventral anterior cingulate cortex, although flow as expected during specific emotion-related tasks, flow decreases performance of some attentionally demanding, cognitive tasks. Conversely, in some of the areas that appear to subserve cognitive functions, as the dorsal anterior cingulate and the dorsolateral prefrontal cortices, increases while performing attentionally demanding cognitive tasks, but during some experimentally induced and pathological emotional Although the specific nature of such reciprocal patterns of regional remains unclear, they may reflect an important cross-modal interaction during mental operations. The possibility that neural activity is less in areas required in emotional processing during some higher cognitive processes holds implications for the mechanisms underlying interactions cognition and emotion. Furthermore, the possibility that neural in some cognitive-processing areas is suppressed during intense states suggests mechanisms by which extreme fear or severe may interfere with cognitive performance.  相似文献   
36.
P Bressan 《Perception》1987,16(5):671-675
If a few parallel horizontal rows of dots are set diagonally, like steps, across the visual field, the inner rows appear not to be horizontal but sloping up to one side; the effect holds as long as the vertical distances between the rows do not exceed a given visual angle. This illusion, described by Vicario in 1978, was never explained. An experiment is reported in which the illusion was still visible at row separations well in excess of the spatial limits originally considered, provided the stimulus elements were enlarged. The maximum illusion was obtained for length ratios (interrow distance to size of dots) identical to those which have been shown to produce the largest effects in a number of illusions of area and length. This suggests that Vicario's illusion is similar to other illusions of extent, and that it can be explained by a neural extent-coding model.  相似文献   
37.
We report an eye movement experiment investigating the influence of the focus operator only on syntactic processing of "long" relative clause sentences. Paterson, Liversedge, and Underwood (1999) found that readers were garden pathed by "short" reduced relative clause sentences containing the focus operator only . They argued that due to thematic differences between "short" and "long" relative clause sentences, garden path effect might not occur when "long" reduced relative clause sentences are read. Eye-tracking data show that garden path effects found during initial processing of the disambiguating verb of "long" reduced sentences without only were absent or delayed in the case of counterparts with only . We discuss our results in terms of current theories of sentence processing.  相似文献   
38.
39.
40.
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