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   23121篇
  免费   797篇
  国内免费   11篇
  23929篇
  2020年   227篇
  2019年   235篇
  2018年   348篇
  2017年   406篇
  2016年   381篇
  2015年   251篇
  2014年   328篇
  2013年   1719篇
  2012年   642篇
  2011年   707篇
  2010年   431篇
  2009年   401篇
  2008年   587篇
  2007年   578篇
  2006年   530篇
  2005年   470篇
  2004年   469篇
  2003年   418篇
  2002年   470篇
  2001年   728篇
  2000年   758篇
  1999年   559篇
  1998年   266篇
  1997年   221篇
  1992年   452篇
  1991年   410篇
  1990年   444篇
  1989年   415篇
  1988年   399篇
  1987年   401篇
  1986年   410篇
  1985年   427篇
  1984年   335篇
  1983年   306篇
  1982年   244篇
  1981年   218篇
  1979年   393篇
  1978年   282篇
  1977年   255篇
  1976年   231篇
  1975年   345篇
  1974年   381篇
  1973年   354篇
  1972年   332篇
  1971年   295篇
  1970年   264篇
  1969年   325篇
  1968年   361篇
  1967年   324篇
  1966年   329篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
A square-wave grating from which the fundamental harmonic has been subtracted (missing fundamental grating) when viewed from a suitable distance appears similar to another grating of periodicity three times higher. The neurons of the visual cortex of the cat, in a given range of spatial frequencies characteristic of each cell, give similar responses to the two gratings.  相似文献   
33.
34.
Gábor L. Ambrus 《Zygon》2020,55(4):875-897
We are easily misguided as to the true nature of Facebook, and tend to treat it simply as a powerful technological instrument in the service of human intentions. We can, however, gain a better picture of it through recourse to the Jewish tradition of the golem, an image of human beings, created by them in a re-enactment of their own creation by God. It turns into a magic servant in modernity with an inherent dynamic running between its human and its subhuman characteristics. This dynamic is the main cause behind its becoming uncontrollable. In like manner, what is subhuman in Facebook serves its masters and functions under their total control, but also empowers Facebook's increasingly human operation, an algorithm-based capability which raises growing doubts about what counts as human. Facebook implies the crisis of humanity which coincides with the “death of God,” that is, the obsolescence of the idea of a divine creator.  相似文献   
35.
Previous research has revealed that individuals have expectations for the development of romance based on personal experience and cultural images. A series of research questions and hypotheses was generated and a sequence of hierarchical log-linear analysis models axis developed to test (a) the effect of gender and knowledge of relational stage and relationship type on prediction of next-occurring actions in the development of a romance, (b) the use of compliance-gaining strategies intended to advance a relationship to the next stage, and (c) justification of secondary goals in which participants reported why they chose the strategies they did as opposed to other alternatives. The data revealed effects for relational stage progression on prediction of ensuing actions. Ingratiation, explanation, and direct requests were popular strategies for developing intimacy. Gender differences in terms of secondary goals were reported. Results are discussed in terms of relational memory structures for the development of intimacy.  相似文献   
36.
This study explored the experience of role conflict for women in infertile couples. The infertile group consisted of 29 women who, with their husbands, were beginning an infertility program; comparison group subjects were 29 married women with no history of inability to conceive. Each subject completed self-report instruments measuring role conceptions and expectations, the experience of role conflict, and occupational commitment. Each husband also reported his role expectations for his ideal woman. Also, a semi-structured interview was conducted with each infertile subject. Compared to the control group, the infertile group's role conceptions were more traditional; they reported less role conflict of various kinds, and they showed greater occupational commitment. They did not differ significantly on degree of wife-husband role discrepancy, or on mother's occupational commitment. These findings lead to an understanding of infertility as part of an interactional system for dealing with potentially intolerable sources of role conflict.  相似文献   
37.
38.
Three experiments used a discriminated operant procedure to study conditional discrimination learning in rats. The first experiment showed that rats were capable of learning a biconditional discrimination in which two contexts served as conditional cues signalling the reinforcement contingencies associated with two discriminative stimuli. The discrimination was learned equally well when one discriminative stimulus signalled food, the other its absence, and when one stimulus signalled food, the other extinction plus mild footshock.

In Experiment 2 it was shown that prior training on such a conditional discrimination enhanced the subsequent context specificity of simple conditioning relative to control groups of animals for whom the prior training had not been conditional. Experiment 3 showed that a reversal of the significance of one pair of discriminative stimuli produced no spontaneous reversal in performance to a second, target, pair.

The pattern of results is best accounted for by an analysis of contextual conditional discrimination learning in terms of stimulus configurations and offers no support for the notion that rats may learn a general conditional rule or set.  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