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   61128篇
  免费   2416篇
  国内免费   24篇
  63568篇
  2020年   713篇
  2019年   835篇
  2018年   1272篇
  2017年   1280篇
  2016年   1401篇
  2015年   987篇
  2014年   1110篇
  2013年   5022篇
  2012年   2232篇
  2011年   2221篇
  2010年   1228篇
  2009年   1261篇
  2008年   1756篇
  2007年   1724篇
  2006年   1603篇
  2005年   2470篇
  2004年   1903篇
  2003年   1666篇
  2002年   1330篇
  2001年   1964篇
  2000年   1820篇
  1999年   1378篇
  1998年   640篇
  1997年   557篇
  1996年   631篇
  1995年   571篇
  1994年   565篇
  1993年   546篇
  1992年   1140篇
  1991年   1058篇
  1990年   1058篇
  1989年   1003篇
  1988年   965篇
  1987年   900篇
  1986年   899篇
  1985年   933篇
  1984年   749篇
  1983年   650篇
  1979年   790篇
  1978年   578篇
  1975年   627篇
  1974年   708篇
  1973年   732篇
  1972年   624篇
  1971年   578篇
  1970年   498篇
  1969年   494篇
  1968年   625篇
  1967年   545篇
  1966年   520篇
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
961.
The major theories and research approaches as to the etiology and development of stuttering are reviewed from a historical perspective. Findings are drawn from different sources indicating that language deficits are an initial contributing factor and a continuing component of this disorder. Those subsets of children which constitute high-risk groups are identified. It is suggested that researchers begin investigating the underlying organic bases of stuttering and its relationship to stages of language development. Finally, clinicians are encouraged to employ a therapy program that is concerned with all areas of language, rather than emphasizing treating only the symptoms of stuttering behavior.  相似文献   
962.
A mathematical model is developed to describe sequential effects in two-choice reaction time experiments with a short response-stimulus interval. Evidence is briefly discussed that in conditions with short response-stimulus intervals, automatic aftereffects dominate sequential effects, and the influence of subjective expectancy can be neglected. In these conditions the model premises three components of automatic aftereffects--facilitation, inhibition, and noise, with a common decay factor. Influence of response-stimulus interval and practice on sequential effects are examined and related to parameter changes in the proposed single-decay model. The decrease of automatic aftereffects with increasing response-stimulus interval is primarily ascribed to an increasing decay factor. The parameter representation of the model also clarifies the issue of the disappearance of automatic aftereffects with practice. It shows a gradual fading of inhibition in the initial stages of practice, together with a slower decrease of the facilitation effect. The single-decay model provides a satisfactory explanation for the processes involved in compatible two-choice reaction time with short response-stimulus interval.  相似文献   
963.
Learned helplessness theory predicts that animals exposed to inescapable shock acquire an expectancy of response-reinforcer independence, which proactively interferes with learning of response-reinforcer dependence. The theory also predicts that this expectancy can increase sensitivity to subsequent instances of response-reinforcer independence. These experiments test the latter prediction in a paradigm that minimizes the confounding effects of shock-induced activity deficits. Rats were trained to respond for food, then given either escapable, inescapable, or no shock. Subsequently, they received two sessions of response-contingent food followed by sessions of noncontingent food deliveries. During this phase, inescapably shocked animals decreased responding faster than did controls. Experiment 2 replicated this finding with a different schedule of food delivery and a procedure that more directly minimized the possibility that the outcome is due to either direct or indirect shock-induced activity changes. These results support the prediction that uncontrollable aversive events can increase an animal's sensitivity to noncontingent response-reinforcer relationships.  相似文献   
964.
965.
966.
Mixed hyperactive/reading-disabled children, selected from a large sample of hyperactive children, were compared to pure hyperactive children on demographic, behavioral, and neuropsychological measures. Children in the Mixed group were reading-disabled relative to age and IQ; those in the Pure group had achievement scores that were average relative to age and IQ. The Mixed group was significantly older than the Pure group; there were no differences in gender, race, or socioeconomic status. Behaviorally, the groups did not differ significantly on teacher ratings or on psychiatric ratings of aggression. The Mixed group had a significantly higher Performance IQ, whereas the Pure group had a significantly higher Verbal IQ and performed better on measures of cognitive impulsivity. Several other measures failed to distinguish the groups. The data give minimal support to the notion that pure hyperactive and mixed hyperative/reading-disabled children constitute distinct subgroups of Attention Deficit Disorder with Hyperactivity.This research was supported in part by Mental Health Clinical Research Grant MH-30906 and by U. S. Public Health Service Grant MH-18579.  相似文献   
967.
The empirical research pertaining to the effectiveness of telephone counseling and referral systems personnel was critically reviewed. The assessment was organized according to several evaluation strategies that researchers have utilized to evaluate effectiveness. These strategies included, for example, client self-reports, client "shows" versus "no-shows" following referral, data pertaining to suicide rates, counselor ratings of personal effectiveness, and phone workers' ability to offer empathy to clients. It was concluded that discussions of effectiveness should be constrained by a careful consideration of the specific index of efficacy chosen by investigators as well as methodological issues associated with current research in this area. There is reason to believe that the availability of telephone crisis services may be related to reduced suicide rates among young white females. Also, there is a significant need to empirically associate counseling technique and indices of effectiveness with substantive measures of client outcome in future research. Additional topics reviewed include the probable differential effectiveness of lay workers with various presenting problems of clients, and the role that training and maturity seem to play in successful interventions. Guidelines for the use of evaluation techniques which coincide with service goals are also offered.  相似文献   
968.
969.
970.
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