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   7301篇
  免费   297篇
  国内免费   5篇
  2023年   63篇
  2022年   74篇
  2021年   100篇
  2020年   151篇
  2019年   154篇
  2018年   242篇
  2017年   258篇
  2016年   253篇
  2015年   190篇
  2014年   231篇
  2013年   885篇
  2012年   411篇
  2011年   359篇
  2010年   221篇
  2009年   235篇
  2008年   292篇
  2007年   327篇
  2006年   256篇
  2005年   207篇
  2004年   221篇
  2003年   200篇
  2002年   155篇
  2001年   129篇
  2000年   127篇
  1999年   114篇
  1998年   75篇
  1997年   61篇
  1996年   51篇
  1995年   54篇
  1994年   55篇
  1993年   54篇
  1992年   56篇
  1991年   47篇
  1990年   70篇
  1989年   52篇
  1988年   51篇
  1987年   57篇
  1986年   62篇
  1985年   60篇
  1984年   63篇
  1983年   57篇
  1982年   40篇
  1981年   46篇
  1980年   48篇
  1979年   59篇
  1978年   49篇
  1976年   51篇
  1975年   60篇
  1974年   63篇
  1973年   46篇
排序方式: 共有7603条查询结果,搜索用时 406 毫秒
51.
The following survey is intended to demonstrate and discuss some principle problems of biomagnetism and the application in clinical fields. The development of special technical parameters especially by the SQUID method is initiating new possibilities of research and completing the neurobiologically determinated basis and conditions of neuropsychiatric disorders. The Magnetoencephalography (MEG) will be represent an important role of a new functional diagnostic method.  相似文献   
52.
53.
Previous research has found that greater autonomy for incarcerated adolescents is associated with pro-social outcomes. The present paper interprets the pro-social impact of autonomy in terms of three established lines of research in social psychology: leadership style, coercive social control, and reactance. In addition, it attempts to clarify whether autonomy in this setting has a direct influence on residents' values or an indirect influence resulting from an increase in residents' acceptance of the treatment goals. Data were collected by questionnaires administered to 434 residents and 156 staff members at four residential institutions for adjudicated adolescents. The data were analyzed using a structural equation model with unobserved variables (LISREL). A model positing both direct and indirect influences of autonomy fit the data very well. Autonomy contributed to pro-social values both through greater acceptance of the treatment goals as well as through a direct influence on values.  相似文献   
54.
Regional cerebral glucose metabolism in aphemia: A case report   总被引:1,自引:0,他引:1  
Local cerebral metabolism was determined in a patient suffering aphemia following cerebral infarction using the 18FDG-PET technique. The syndrome was characterized by profound ictal nonfluency with sparing of other language functions. Speech subsequently improved so that content and grammar were appropriate but mild dysprosody persisted. Conventional CT showed no lesion of the left hemisphere while PET revealed a discrete focus of hypometabolism on the left which partially resolved on serial studies. The metabolic lesion could be localized to the region of the inferior precentral gyrus and the adjacent subcortical space.  相似文献   
55.
56.
Two studies were conducted to examine how response selection strategy is related to confidence ratings and to performance on general knowledge questions. In both studies subjects were asked to answer 80 general knowledge questions and to rate their confidence in the correctness of the answer selected. A pilot study, in which subjects thought aloud while answering general knowledge questions, was carried out to identify different response selection strategies. In the first study, 40 subjects were asked to indicate which of four strategies (immediate recognition, inference, intuition, or guessing) they used for selecting an answer. In Study 2, think aloud reports from 20 subjects were coded into the same four strategies. The distribution of strategies differed between the studies, but there were very similar relations among strategy, confidence, and correctness of answer in the two studies. Response selection strategy was related to correctness of answer when confidence was partialed out. More specifically, immediate recognition was associated with higher proportion correct than with the other strategies. It was also found that ratings of how difficult the knowledge questions were to fellow students of the subjects were on a much more realistic level than the confidence ratings were. It is concluded that people could improve their confidence judgments by taking into account (a) how difficult a question is to other people, and (b) the response selection strategy used for answering the question.  相似文献   
57.
Mediaeval logicians inherited from Boethius an account of conditional propositions and the syllogisms which may be constructed using them. In the following paper it is shown that there are considerable difficulties with Boethius' account which arise from his failure to understand the nature of compound propositions and in particular to provide for their negation. Boethius suggests that there are two different conditions which may be imposed for the truth of a conditional proposition but he really gives no adequate account of how such propositions may be obtained. The true greatness of Peter Abaelard as a philosophical logician is revealed in what he is able to do with the material which he found in Boethius. It is shown that he developed a precise theory of conditionals giving an account of how true conditionals may be obtained and principles which may be used to reject others as false. Unlike Boethius Abaelard properly appreciates that conjunctions must be treated as logical units. Even he, however, falls victim to difficulties which arise when this connective is brought into contact with negation and the conditions which he lays down for the truth of a conditional.  相似文献   
58.
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   
59.
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   
60.
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   
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