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   65718篇
  免费   2518篇
  国内免费   18篇
  2019年   776篇
  2018年   1088篇
  2017年   1051篇
  2016年   1139篇
  2015年   806篇
  2014年   996篇
  2013年   5606篇
  2012年   1775篇
  2011年   1868篇
  2010年   1157篇
  2009年   1139篇
  2008年   1711篇
  2007年   1589篇
  2006年   1491篇
  2005年   1309篇
  2004年   1279篇
  2003年   1242篇
  2002年   1228篇
  2001年   2023篇
  2000年   1894篇
  1999年   1456篇
  1998年   730篇
  1996年   756篇
  1995年   730篇
  1994年   709篇
  1992年   1344篇
  1991年   1260篇
  1990年   1221篇
  1989年   1171篇
  1988年   1169篇
  1987年   1111篇
  1986年   1140篇
  1985年   1167篇
  1984年   1007篇
  1983年   879篇
  1982年   723篇
  1981年   716篇
  1979年   1020篇
  1978年   763篇
  1976年   699篇
  1975年   914篇
  1974年   949篇
  1973年   1021篇
  1972年   919篇
  1971年   814篇
  1970年   773篇
  1969年   777篇
  1968年   942篇
  1967年   826篇
  1966年   808篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
The ability of two species of tits to remember the location and/or features of an object was tested in a delayed-matching-to-sample procedure. Three values of retention interval between presentation of the sample stimulus and the choice--30 sec, 5 min, and 15 min--were used. Both species performed at above-chance level at all retention intervals, and there was no significant decline in accuracy with increasing interval. A pool of 100 stimulus objects was used, but the results of control trials indicated that the birds responded primarily to location rather than stimulus features of the object itseif. Although the food-storing marsh tit tended to perform at a higher level than the non-storing great tit, the only significant difference between the species was in the first 50 trials of the first treatment, when the birds were acquiring the task. The results are discussed in relation to the hypothesized special memory capacity of food-storing birds.  相似文献   
32.
Experiment 1 replicated Yaniv and Meyer's (1987) finding that lexical decision and episodic recognition performance was better for words previously yielding high-accessibility levels (a combination of feeling-of-knowing and tip-of-the-tongue ratings) in comparison with those yielding low-accessibility levels in a rare word definition task. Experiment 2 yielded the same pattern even though lexical decisions preceded accessibility estimates by a full week. Experiment 3 dismissed the possibility that the Experiment 2 results may have been due to a long-term influence from the lexical decision task to the rare word judgment task. These results support a model in which Ss (a) retrieve topic familiarity information in making accessibility estimates in the rare word definition task and (b) use this information to modulate lexical decision performance.  相似文献   
33.
34.
35.
As the complexity of the challenges presented by our interactions with our planet continues to grow, we must develop new modes of knowledge production. In these modes, distinctions between multidisciplinary and inter-disciplinary activities and processes have renewed importance. There are at least two distinct types of interdisciplinary activities distinguished by the disciplinary breadth they attempt to bridge. In the narrow case, reductionist processes reveal a common underlying principle or process which can serve as a Rosetta stone. In the broad case, no such common arbiter exists. Investigators must develop integrating vocabulary in the context of the full breadth of their work. His primary activities are the fostering of university-wide interdisciplinary research and curriculum programs focused on global change with the goal of developing Columbia into a world leader in issues related to global stewardship.  相似文献   
36.
37.
38.
Convergent and divergent stereo mechanisms were compared in their ability to recover structure from motion. Contrary to a recent result reported by Richards and Lieberman, no difference in their performance was found; both mechanisms appeared equally capable of supporting the perception of good structure from motion. Possible reasons for the disparate results are discussed.  相似文献   
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