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   27105篇
  免费   1020篇
  国内免费   13篇
  2020年   339篇
  2019年   318篇
  2018年   527篇
  2017年   564篇
  2016年   587篇
  2015年   402篇
  2014年   511篇
  2013年   2279篇
  2012年   887篇
  2011年   891篇
  2010年   563篇
  2009年   546篇
  2008年   764篇
  2007年   773篇
  2006年   655篇
  2005年   568篇
  2004年   569篇
  2003年   520篇
  2002年   554篇
  2001年   798篇
  2000年   854篇
  1999年   617篇
  1998年   289篇
  1997年   247篇
  1996年   232篇
  1992年   474篇
  1991年   431篇
  1990年   474篇
  1989年   444篇
  1988年   415篇
  1987年   425篇
  1986年   427篇
  1985年   438篇
  1984年   361篇
  1983年   318篇
  1982年   252篇
  1979年   417篇
  1978年   290篇
  1977年   267篇
  1976年   236篇
  1975年   364篇
  1974年   398篇
  1973年   366篇
  1972年   348篇
  1971年   303篇
  1970年   287篇
  1969年   329篇
  1968年   375篇
  1967年   333篇
  1966年   338篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
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   
62.
We examined the effects of acute psychological stress on lymphocyte proliferation and circulating levels of interleukin-1 and -2. Healthy men were exposed to two viewings of a gruesome surgery film and were asked to recall details of the film twice during a 30-min period. These subjects were compared to a nonstress control group. Lymphocyte proliferation to the mitogen concanavalin A (Con A; 5 micrograms/ml) was decreased during and after exposure to the stressor when compared to the control group. This decrease was more pronounced in subjects exhibiting greater blood pressure reactivity while viewing the film than in subjects showing smaller blood pressure responses. None of the other immunological measures was significantly affected by the stressor. Cortisol was not correlated with lymphocyte responsiveness. Possible explanations for these results and implications for further research are discussed.  相似文献   
63.
64.
65.
66.
67.
68.
This study examined the effect of high and low communication apprehension in conjunction with social and personal settings upon verbal behavior. Step wise multiple discriminant analysis of the data indicated a linear combination of language indices (number of syllables, Noun-Verb/Adjective-Adverb ratio, and phrase repetitions) which discriminated between the high apprehensive-personal setting group and the remaining three groups. Results are discussed relative to theoretical projections and the potential for sensitivity toward communication behavior being operative within the communication apprehension framework.  相似文献   
69.
A comparison of two measures of egocentrism   总被引:1,自引:0,他引:1  
This study examined the relationship between two prominent measures of egocentrism, Enright's Adolescent Egocentrism Scale (AES) and Elkind's Imaginary Audience Scale (IAS), in a sample of 458 adolescents, between 10 and 15 years old. Both correlational and factor analyses indicated that the two measures assess distinctly different phenomena. As predicted, IAS scores were correlated with self-reported levels of shyness, nervousness, and social skills. These results provide partial evidence for the validity of the IAS as a measure of self-consciousness, though not necessarily egocentrism per se. The validity of the AES was not examined.  相似文献   
70.
In this study, we examined factors associated with relapse and maintenance following a self-management training course. Thirty-five community professionals participated in a 3-week (30-hr) graduate-level extension course in self-management, which included a self-modification project. Results at a 10-week follow-up showed that end-of-class self-efficacy and outcome expectancy correctly classified over 80% of those who maintained gains in their projects versus those who relapsed. The professionals in the relapsed group also reported significantly more difficulty with anticipated high-risk situations than did those in the maintenance group.  相似文献   
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