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   51216篇
  免费   1994篇
  国内免费   18篇
  2019年   548篇
  2018年   821篇
  2017年   759篇
  2016年   882篇
  2015年   636篇
  2014年   772篇
  2013年   4588篇
  2012年   1372篇
  2011年   1343篇
  2010年   896篇
  2009年   843篇
  2008年   1259篇
  2007年   1204篇
  2006年   1106篇
  2005年   978篇
  2004年   907篇
  2003年   900篇
  2002年   898篇
  2001年   1741篇
  2000年   1685篇
  1999年   1265篇
  1998年   558篇
  1996年   631篇
  1995年   592篇
  1994年   592篇
  1993年   553篇
  1992年   1202篇
  1991年   1118篇
  1990年   1105篇
  1989年   967篇
  1988年   945篇
  1987年   938篇
  1986年   913篇
  1985年   908篇
  1984年   810篇
  1983年   675篇
  1982年   543篇
  1981年   554篇
  1979年   766篇
  1978年   595篇
  1975年   717篇
  1974年   734篇
  1973年   799篇
  1972年   730篇
  1971年   667篇
  1970年   573篇
  1969年   588篇
  1968年   726篇
  1967年   631篇
  1966年   585篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
921.
922.
The results of an evaluation of the perfusion scintigraphy findings of 350 hospitalised neurological patients and 55 more strictly selected neurosurgical patients with cerebrovascular complaints, revealed an accuraty of 83%, a sensitivity of 89%, and a specificity of 83%. The selection of the patients had no influence on the results as a whole. Compared with contrast-medium angiography, incorrect diagnosis must be expected in 17% of the cases. This includes erroneous negative findings in 10% of the cases. Grounds for misinterpretations are suggested, and the biological and methodological limitations of the method are set forth.  相似文献   
923.
The use of computer based diagnostic decision and artificial intelligence are discussed in relation to the problems of validity and reliability of psychiatric diagnoses. The authors suggest a definition of a computer aided classificator as an existent decision system for an automatically analysis of findings.  相似文献   
924.
This article attempts to apply a theory of aggression as motivation to overcome obstacles to the understanding of phobic states and their formation. The role of aggression in the genesis of phobic conditions is discussed, and the traditional analytic view of aggression as instinctual drive is contrasted with a motivational approach. The motivational view offers the advantage of a clearer understanding of the stimulus contexts, representational connections, and both real and imaginary object connections that are lacking in the more traditional understanding of aggression as a biological drive.  相似文献   
925.
926.
927.
Two studies are reported on a new Anger Control Inventory based on a cognitive-behavioral person-situation interaction model. In Study 1, the inventory responses of 118 clinical subjects and 190 normal subjects were correlated with an anger problem criterion based on observable signs. Factor analyses were conducted to clarify the construct base of the inventory. In Study 2, comparisons were made between the inventory responses of 100 spouse batterers and 96 normal subjects. Significant differences between the pretreatment and posttreatment scores of 65 batterers given treatment in anger control were obtained on the inventory scales, which were found to be correlated with the problem criterion and discriminating between the clinical and normal groups. The construct validity and clinical utility of the Anger Control Inventory are discussed.  相似文献   
928.
A short-form measure of loneliness   总被引:5,自引:0,他引:5  
The revised UCLA Loneliness Scale (ULS-20) and a four-item short form (ULS-4) are widely used in personality research (Russell, Peplau, & Cutrona, 1980). In an exploratory factor analysis of the ULS-20, we identified eight items that loaded substantially on the first factor. These items were combined to form an alternative short-form measure, the ULS-8. The results of this study indicate that the ULS-8 is reliable, valid, and a better substitute for the ULS-20 than is the ULS-4. Consistent with the previous research, the loneliness measures (ULS-20, ULS-8, ULS-4) were strongly related to socially undesirable personality characteristics, but loneliness was uncorrelated with the six different health-related behaviors (exercise, meal regularity, alcohol use, hard drug use, smoking, and hours of sleep) assessed in this study.  相似文献   
929.
This study explored the relationship among love deprivation, Performance greater than Verbal discrepancy, and violent crime in a sample of juvenile probationers. Love deprivation and P greater than V discrepancy was significantly related to violent delinquency after adjusting for the effects of both race and social class, two variables often closely associated with violent delinquency. Also, love deprivation was strongly related to P greater than V discrepancy. We speculated that high performance IQ scores relative to verbal scores are a function of a lack of disruption in the short-term memory mechanisms of high P greater than V subjects, that this nondisruption is a function of hyporeactive autonomic nervous systems, and that this hyporeactivity could itself be a function of early love deprivation.  相似文献   
930.
Stimulus class membership established via stimulus-reinforcer relations   总被引:4,自引:4,他引:0  
In an arbitrary matching-to-sample procedure, two mentally retarded subjects learned conditional discriminations with two sets of stimuli. Each set included a spoken name (N1 or N2), an object (O1 or O2), and a printed symbol (S1 or S2). One subject selected conditionally (a) O1 upon N1, and O2 upon N2, and (b) S1 upon O1, and S2 upon O2. The other subject selected conditionally (a) S1 upon N1, and S2 upon N2, and (b) O1 upon S1, and O2 upon S2. For both subjects, selections of O1 and S1 produced one type of food, F1; selections of O2 and S2 produced a different type of food, F2. Both subjects also learned identity-matching performances, selecting O1, O2, S1, S2, F1, and F2 conditionally upon those stimuli as samples; F1 followed selections of O1, S1, and F1; F2 followed selections of O2, S2, and F2. Matching performances consistent with stimulus class formation involving the names, objects, symbols, and foods were demonstrated on probe trials, even though these performances had not been taught explicitly. Next, new objects, X1 and X2, were presented on identity-matching trials, producing F1 and F2, respectively. Without further training, X1 was selected conditionally upon N1, S1, and O1, and X2 was selected upon N2, S2, and O2. When the contingencies were changed so that selections of X1 and X2 were now followed by F2 and F1, respectively, X2 was selected conditionally upon N1, S1, and O1, and X1 was selected upon N2, S2, and O2. Class membership of X1 and X2 had apparently changed. This study provides evidence that reinforcers may become members of stimulus classes, and that new stimuli may become class members through relations with reinforcers.  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