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   58826篇
  免费   2264篇
  国内免费   23篇
  2020年   578篇
  2019年   625篇
  2018年   895篇
  2017年   954篇
  2016年   1016篇
  2015年   726篇
  2014年   864篇
  2013年   4219篇
  2012年   1685篇
  2011年   1698篇
  2010年   1063篇
  2009年   1001篇
  2008年   1480篇
  2007年   1480篇
  2006年   1305篇
  2005年   1243篇
  2004年   1165篇
  2003年   1052篇
  2002年   1112篇
  2001年   1869篇
  2000年   1814篇
  1999年   1356篇
  1998年   625篇
  1997年   536篇
  1992年   1229篇
  1991年   1128篇
  1990年   1179篇
  1989年   1054篇
  1988年   1024篇
  1987年   1030篇
  1986年   1040篇
  1985年   1108篇
  1984年   854篇
  1983年   805篇
  1982年   577篇
  1981年   540篇
  1979年   999篇
  1978年   668篇
  1977年   633篇
  1976年   605篇
  1975年   863篇
  1974年   983篇
  1973年   996篇
  1972年   878篇
  1971年   811篇
  1970年   779篇
  1969年   823篇
  1968年   1045篇
  1967年   912篇
  1966年   867篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
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   
962.
The paper is concerned with an attempt to generalize and categorize current hypotheses on the biochemical basis of ECT. The hypotheses are critically evaluated with respect to the relevance of their experimental fundamentals. Thus, certain hypotheses are valid only in a qualified sense. Particular interest is focussed on those conceptions which try to correlate ECT-induced changes in synaptic receptor sensitivities (up-/down-regulation) with super- resp. subsensitivity hypotheses of psychoses. In this connection, noradrenergic and opioid systems on the one hand, and the axis hypothalamus-hypophysis on the other hand seem to play a dominant role.  相似文献   
963.
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   
964.
Investigating the specific of psychic performance disorders in epileptics structural aspects in addition to quantitative performance differences are considerable. We compared psychometrically obtained performance structures of epileptic children and adults and of parallelised healthy control persons. It became evident, that the performance differentiation hypothesis is to corroborate also in epileptic patients. The psychic performance structure of epileptics is characterized by a lower differentiation level of the basis functions underlining the performances. Our factor analytic investigations emphasize the importance of deceleration of psychic/psychomotoric speed in epileptics as primary basic disorder.  相似文献   
965.
Intrathecal methotrexate-overdosage in the meningosis therapy leads to CNS damages dependent on dose. It was given a own case report and a literature review with clinical symptoms and the therapy in this complication. Neuropathologic findings included demyelinisation und necrosis of the white matter.  相似文献   
966.
An investigation into the diagnostic value of psychometric methods for the diagnosis of depressive states involved five psychometric questionnaires, one concentration test procedure, and one problem-solving approach to register cognitive processes. The data obtained for 80 depressive patients of varied aetiology were compared with those of sample of 80 neurotics without depressive aberration. Even univariate comparisons revealed statistically significant differences between the two samples. Multivariate methods (factor analysis, discriminative analysis) yielded more differentiated information. The "Scale for depression depth measurements" was found to be of particular diagnostic relevance; it was standardized for the time being.  相似文献   
967.
968.
969.
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   
970.
Recipient's mood, relationship type, and helping   总被引:6,自引:0,他引:6  
We conducted two studies to examine how a potential helper is affected by having a communal orientation toward a relationship with a potential recipient and by the potential recipient's sadness. We hypothesized that (a) having a communal orientation would increase helping and that (b) people high in communal orientation, but not others, would respond to a potential recipient's sadness by increasing helping. These hypotheses were tested in two studies. In Study 1, individual differences in communal orientation toward relationships were measured by using a new communal orientation scale reported for the first time in this article. In Study 2, manipulations were used to lead subjects to desire either a communal or an exchange relationship with another person. In both studies, subjects were exposed to a sad person or to a person in a neutral mood whom they were given a chance to help. As hypothesized, in both studies communally oriented subjects helped the other significantly more than did others. Also as hypothesized, in both studies communally oriented subjects but not others, increased helping in response to the other person's sadness although this effect reached statistical significance only in the second study.  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