全文获取类型
收费全文 | 49700篇 |
免费 | 2099篇 |
国内免费 | 34篇 |
专业分类
51833篇 |
出版年
2020年 | 562篇 |
2019年 | 625篇 |
2018年 | 960篇 |
2017年 | 882篇 |
2016年 | 984篇 |
2015年 | 645篇 |
2014年 | 840篇 |
2013年 | 3765篇 |
2012年 | 1533篇 |
2011年 | 1582篇 |
2010年 | 895篇 |
2009年 | 1028篇 |
2008年 | 1354篇 |
2007年 | 1371篇 |
2006年 | 1234篇 |
2005年 | 1085篇 |
2004年 | 1041篇 |
2003年 | 990篇 |
2002年 | 963篇 |
2001年 | 1702篇 |
2000年 | 1672篇 |
1999年 | 1260篇 |
1998年 | 522篇 |
1997年 | 493篇 |
1995年 | 471篇 |
1992年 | 1019篇 |
1991年 | 931篇 |
1990年 | 971篇 |
1989年 | 889篇 |
1988年 | 864篇 |
1987年 | 796篇 |
1986年 | 818篇 |
1985年 | 901篇 |
1984年 | 725篇 |
1983年 | 638篇 |
1982年 | 503篇 |
1979年 | 750篇 |
1978年 | 555篇 |
1977年 | 483篇 |
1976年 | 491篇 |
1975年 | 620篇 |
1974年 | 739篇 |
1973年 | 773篇 |
1972年 | 644篇 |
1971年 | 542篇 |
1970年 | 492篇 |
1969年 | 532篇 |
1968年 | 667篇 |
1967年 | 586篇 |
1966年 | 591篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
15.
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
16.
17.
Simon P. Liversedge Kevin B. Paterson Emma L. Clayes 《The Quarterly Journal of Experimental Psychology Section A: Human Experimental Psychology》2002,55(1):225-240
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
18.
19.
20.