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   27069篇
  免费   222篇
  国内免费   3篇
  2020年   67篇
  2019年   90篇
  2018年   3640篇
  2017年   2953篇
  2016年   2369篇
  2015年   279篇
  2014年   175篇
  2013年   573篇
  2012年   790篇
  2011年   2610篇
  2010年   2659篇
  2009年   1594篇
  2008年   1900篇
  2007年   2391篇
  2006年   177篇
  2005年   351篇
  2004年   292篇
  2003年   218篇
  2002年   185篇
  2001年   247篇
  2000年   257篇
  1999年   160篇
  1998年   76篇
  1997年   71篇
  1996年   72篇
  1992年   121篇
  1991年   121篇
  1990年   126篇
  1989年   100篇
  1988年   90篇
  1987年   98篇
  1986年   112篇
  1985年   107篇
  1984年   97篇
  1983年   82篇
  1979年   95篇
  1978年   70篇
  1977年   62篇
  1976年   56篇
  1975年   68篇
  1974年   92篇
  1973年   101篇
  1972年   72篇
  1971年   69篇
  1970年   80篇
  1969年   76篇
  1968年   106篇
  1967年   82篇
  1966年   93篇
  1958年   62篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
191.
In rats, pretraining ip administration of the central benzodiazepine receptor antagonist, flumazenil (5.0 mg/kg), or of the inverse agonist, n-butyl-beta-carboline-3-carboxylate (BCCB) (0.2 or 0.5 mg/kg), facilitated retention of a step-down inhibitory avoidance task; the central agonists, clonazepam and diazepam (0.4 or 1.0 mg/kg), had an opposite effect, and the peripheral agonist, 4'-chlordiazepam (1.25 or 6.25 mg/kg), was without effect. Pre- but not post-training flumazenil (2.0 mg/kg) blocked the effect of BCCB (0.5 mg/kg), clonazepam (1.0 mg/kg), or diazepam (1.0 mg/kg) given also pretraining. The post-training administration of all of these drugs had no effect on retention of the avoidance task. Flumazenil (5.0 mg/kg) and BCCB (0.5 mg/kg), given before training, enhanced retention test performance of habituation to a buzzer but not of habituation to an open field. In the three tasks studied, none of the drugs used had any appreciable effect on training session parameters. These results suggest that there is an endogenous mechanism mediated by benzodiazepine agonists, sensitive to inverse agonists, that normally down-regulates acquisition of certain behaviors; this mechanism becomes activated only when the tasks involve or occur with a certain degree of stress or anxiety (i.e., inhibitory avoidance or habituation to the buzzer) and not in less stressful or anxiogenic tasks (i.e., habituation to an open field).  相似文献   
192.
The relationship between sex role flexibility and prosocial behavior among preschool children was investigated. Subjects included 16 boys and 18 girls, ranging in age from 36 to 60 months, from intact families of the upper middle class. A nonhierarchical multiple regression analysis was undertaken to determine the contributions of the predictor variables of sex, age, IQ, and sex role flexibility, as well as their interactions with prosocial behavior (criterion variable). Results indicated that while the overall regression model was not significant, the variable of Sex × Sex Role Flexibility did contribute significantly to the model. Inspection of the correlation coefficients associated with this variable revealed that while sex role flexibility and prosocial behavior among boys were significantly and positively related, among girls no significant relationship was found.  相似文献   
193.
It was hypothesized that older widows (N=309) who had been care givers to their husbands would have undertaken a greater number of household responsibilities than had women who had not been care givers. Findings indicated that, prior to the husband's death, more traditionally male and more traditionally female tasks were performed by the care-giving wives (n=158). This was particularly true in the case of Alzheimer's care givers (n=21). More importantly, widows' present feelings of competence were related to undertaking household responsibilities, with those who had been care givers expressing significantly higher levels of competence.  相似文献   
194.
This study was designed to analyze whether Mental Rotation (MR) played a role as a mediating variable for sex-related differences in Visualization (VZ). Two psychometric tests measuring MR and VZ were applied to a representative sample of 309 males and 390 females in their last year of high school. Three non-zero correlations between sex and MR, sex and VZ, and MR and VZ were found, and the effect of sex on VZ was eliminated when MR was introduced as a covariable. When three subgroups of different VZ ability were made by dividing up the VZ distribution by the first and third quartiles, sex-differences were only found for the high-scorers group, for which previous results were replicated. Results clearly indicate that MR is a plausible mediator variable for sex differences in VZ when such differences do exist. Theoretical, methodological and practical consequences of these results are discussed.  相似文献   
195.
Prime Minister Yitzhak Rabin's assassination has less of a lasting impact on the Israeli public's political values, beliefs and attitudes than might have been anticipated from the magnitude of the event and intensity of the immediate responses. Why did the assassination have such a short-lived effect? This article considers the puzzle as a specific case of the broader phenomenon of collective political trauma and its consequences for values, beliefs and attitudes held by the mass public toward issues that it associates with the traumatic event. The article offers six deductively inferred hypotheses that describe, explain and link affective, cognitive and behavioral aspects of collectively experienced trauma. These hypotheses form a pre-theory explaining the perseverence of core political cognitions, even in the face of a considerable challenge to their validity and relevance.  相似文献   
196.
197.
Relation algebras from cylindric and polyadic algebras   总被引:1,自引:0,他引:1  
  相似文献   
198.
199.
Strong representability of fork algebras, a set theoretic foundation   总被引:1,自引:0,他引:1  
  相似文献   
200.
Current status of the Rorschach Inkblot Method   总被引:1,自引:0,他引:1  
The current scientific, clinical, and professional status of the Rorschach Inkblot Method (RIM) is reviewed with respect to its psychometric properties, the applied purposes it can be expected to serve, the extent of its use, and the nature of prevailing attitudes toward it. Available evidence indicates that the RIM is a psychometrically sound measuring instrument that provides valid assessments of personality characteristics and can facilitate differential diagnosis and treatment planning and evaluation. The RIM continues as in the past to be widely used by both clinicians and researchers. However, the esteem in which it is held by practitioners, who are generally agreed that clinical psychologists should be competent in Rorschach assessment, is not universally shared by academicians, many of whom presently question the future place of Rorschach training in graduate education.  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