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   59327篇
  免费   2395篇
  国内免费   18篇
  2020年   549篇
  2019年   740篇
  2018年   987篇
  2017年   1007篇
  2016年   1076篇
  2015年   782篇
  2014年   920篇
  2013年   4318篇
  2012年   1729篇
  2011年   1894篇
  2010年   1171篇
  2009年   1164篇
  2008年   1682篇
  2007年   1696篇
  2006年   1553篇
  2005年   1361篇
  2004年   1261篇
  2003年   1184篇
  2002年   1300篇
  2001年   1966篇
  2000年   1941篇
  1999年   1469篇
  1998年   683篇
  1997年   609篇
  1996年   608篇
  1993年   549篇
  1992年   1247篇
  1991年   1141篇
  1990年   1127篇
  1989年   1030篇
  1988年   1019篇
  1987年   973篇
  1986年   1044篇
  1985年   1051篇
  1984年   878篇
  1983年   808篇
  1982年   561篇
  1981年   561篇
  1979年   940篇
  1978年   668篇
  1975年   766篇
  1974年   819篇
  1973年   910篇
  1972年   771篇
  1971年   726篇
  1970年   643篇
  1969年   670篇
  1968年   860篇
  1967年   781篇
  1966年   659篇
排序方式: 共有10000条查询结果,搜索用时 875 毫秒
951.
952.
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   
953.
The paper investigates 54 myelograms and their influence on diagnostic thinking efficacy, on patient management efficacy, and on ultimate outcome efficacy, using statistical methods. Conventional myelography contributes to diagnostic thinking efficacy having a LLR- value of approximately 0.9. With an accuracy value of 0.95 it can be regarded as a reliable method of diagnosis. It alters diagnostic thinking efficacy in no less than 83% (94%) of the cases and patients management efficacy in 89%. Thus, by definition, myelography may be said to affect the state of health of the myelographed patients in 94.4%.  相似文献   
954.
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   
955.
Four of our own cases that presented a clinical picture of dementia are discussed. A study of the relative literature has failed to reveal any "swing" in the pattern of the clinical condition: Just as it did ninety years age, paralytic dementia accounts today for well over 60% of all cases, those clinical pictures erroneously regarded as "typical" "classic", accounting for a mere 10%-15% of cases. The need for routine lues serology is pointed out.  相似文献   
956.
957.
958.
959.
In this study we investigated the immediate and continued impact on women of a major stressful event, the outcome of pregnancy, and the mitigating effect of self-esteem and intimacy with their spouse on their reactions. Few other studies have investigated initial reactions to crisis events. Ninety-nine Israeli women who experienced either normal delivery or pregnancy complications were interviewed at the time of the event and 3 months later. High self-esteem was found to limit feelings of depression at both times. Intimacy with spouse limited depression at the event, but not at follow-up. High self-esteem was seen as always being exploitable by women who possessed it, whereas the benefit of intimacy with spouse was seen as being dependent on situational demands and environmental constraints. Cross-cultural implications were presented.  相似文献   
960.
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   
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