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   96793篇
  免费   3981篇
  国内免费   49篇
  100823篇
  2020年   1123篇
  2019年   1373篇
  2018年   1950篇
  2017年   1972篇
  2016年   2059篇
  2015年   1434篇
  2014年   1745篇
  2013年   8351篇
  2012年   3188篇
  2011年   3300篇
  2010年   1997篇
  2009年   2038篇
  2008年   2957篇
  2007年   2927篇
  2006年   2600篇
  2005年   2288篇
  2004年   2317篇
  2003年   2138篇
  2002年   2118篇
  2001年   3108篇
  2000年   2965篇
  1999年   2278篇
  1998年   1165篇
  1997年   998篇
  1996年   1008篇
  1995年   963篇
  1994年   929篇
  1993年   952篇
  1992年   1827篇
  1991年   1712篇
  1990年   1704篇
  1989年   1572篇
  1988年   1542篇
  1987年   1450篇
  1986年   1471篇
  1985年   1570篇
  1984年   1271篇
  1983年   1095篇
  1982年   864篇
  1979年   1299篇
  1978年   967篇
  1976年   848篇
  1975年   1093篇
  1974年   1215篇
  1973年   1211篇
  1972年   1056篇
  1971年   945篇
  1968年   1054篇
  1967年   983篇
  1966年   899篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
971.
Within a multivariate statistical design, the relationship of various interpersonal, emotional, and cognitive variables to suicidal ideation and behavior in college students was examined. A total of 158 subjects (58 males, 100 females) completed self-report measures of life stress, faulty cognitions, loneliness, depression, hopelessness, family cohesiveness, adaptive reasons for living, and suicidal ideation and behavior. The results of a multiple-regression analysis, forward-inclusion algorithm, indicated that a predictive equation consisting of loneliness, irrational beliefs, and low adaptive reasons for living best accounted for suicidal behavior scores. To determine the basic structures and power of the predictor variables under study, a factor analysis and composite regression were employed, resulting in a predictive equation consisting of three factors: Social/Emotional Alienation, Cognitive Distortions, and Deficient Adaptive Resources. Results are discussed in terms of an interactional model of suicidal behavior.  相似文献   
972.
973.
Daily life events were grouped according to their life content area and according to the desirability of the event as rated by the subject. Associations among event groupings and concurrently measured daily mood were examined. As in studies of major life events, some event classifications were more strongly associated with mood than were others: Specifically, desirable family-leisure events and undesirable work events were strongly related to mood. The results suggests that particular life areas deserve special attention in understanding environmental stress.  相似文献   
974.
To evaluate expectations derived from ego-identity theory and symbolic-interaction theories about the association between self-concept and peer-group affiliations in adolescence, we examined the self-esteem of 221 7th through 12th graders associated by peers with one of five major school crowds and 106 students relatively unknown by classmates and not associated with any school crowd. Among crowd members, self-esteem was directly related to the position of one's crowd in the peer-group status hierarchy (based on both peer-rated and self-perceived crowd affiliation). Outsiders' self-esteem differed in relation to the accuracy of their reflected appraisal of and the salience they attached to crowd affiliation. Crowd members as a whole exhibited higher self-esteem than outsiders as a whole. Differences, however, were mediated by crowd status, salience of crowd affiliation, and the accuracy of reflected appraisals. An adequate interpretation of the findings required an integration of Festinger's (1954, 1957) social comparisons and cognitive-dissonance theories, Cooley's (1902) notions of reflected appraisal, and Newman and Newman's (1976) extrapolations from ego-identity theory.  相似文献   
975.
976.
A classifier based on the linear regression model was developed to automatically detect sharp transients in EEG, matching the definition of spikes and sharp waves accepted by IFSECN. Practical applications proved the accuracy of the method which succeeded in detecting 84% of sharp transients previously found by an experienced electronencephalographer. Computerized search for sharp transients in EEG records will be particularly useful in long term EEG records obtained from epileptic patients.  相似文献   
977.
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   
978.
979.
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   
980.
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