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   22756篇
  免费   936篇
  国内免费   15篇
  2020年   273篇
  2019年   265篇
  2018年   442篇
  2017年   374篇
  2016年   406篇
  2015年   269篇
  2014年   387篇
  2013年   1691篇
  2012年   659篇
  2011年   716篇
  2010年   383篇
  2009年   474篇
  2008年   644篇
  2007年   622篇
  2006年   575篇
  2005年   498篇
  2004年   491篇
  2003年   477篇
  2002年   439篇
  2001年   809篇
  2000年   806篇
  1999年   600篇
  1998年   252篇
  1997年   233篇
  1996年   206篇
  1992年   496篇
  1991年   438篇
  1990年   495篇
  1989年   416篇
  1988年   398篇
  1987年   378篇
  1986年   396篇
  1985年   454篇
  1984年   347篇
  1983年   296篇
  1982年   232篇
  1979年   341篇
  1978年   270篇
  1977年   217篇
  1976年   223篇
  1975年   315篇
  1974年   359篇
  1973年   363篇
  1972年   284篇
  1971年   254篇
  1970年   216篇
  1969年   233篇
  1968年   291篇
  1967年   258篇
  1966年   278篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The fibrin(ogen) degradation product concentration is another differential-diagnosis parameter for distinguishing between artificially blood-stained and essentially blood-stained CSF. Determination of the fibrin(ogen) degradation product concentration has been found to be a reliable method of recognizing natively and artificially blood-stained CSF as being different.  相似文献   
992.
993.
Determinate solutions for the indeterminate common factor ofp variables satisfying the single common factor model are not unique. Therefore an infinite sequence of additional variables that conform jointly with the originalp variables to the original single common factor model does not determine a unique solution for the indeterminate factor of thep variables (although the solution is unique for the factor of the infinite sequence). Other infinite sequences may be found to determine different solutions for the factor of the originalp variables. The paper discusses a number of theorems about the effects of additional variables on factor indeterminacy in a model with a single common factor and draws conclusions from them for factor theory in general.  相似文献   
994.
In the applications of maximum likelihood factor analysis the occurrence of boundary minima instead of proper minima is no exception at all. In the past the causes of such improper solutions could not be detected. This was impossible because the matrices containing the parameters of the factor analysis model were kept positive definite. By dropping these constraints, it becomes possible to distinguish between the different causes of improper solutions. In this paper some of the most important causes are discussed and illustrated by means of artificial and empirical data.The author is indebted to H. J. Prins for stimulating and encouraging discussions.  相似文献   
995.
996.
997.
998.
999.
Summary A set of stimuli to be used in psychological experiments is presented. Drawn spontaneously by the Ss, these stimuli are outline forms which can be freely reproduced in an experimental situation. The complexity and meaning-fulness of 100 forms were investigated. Meaningfulness depended on two variables: the probability of a given form having a certain meaning for a S, and the homogeneity of the meanings a given number of Ss ascribe to this form. Three types of meaningfulness could be distinguished: forms with one meaning only, ambiguous forms and nonsense forms. Complexity, homogeneity and probability of having a meaning are listed for all 100 forms.This research was carried out as part of a doctoral dissertation at the Department of Behavior Science of the Swiss Federal Institute of Technology in Zurich. The author expresses gratitude firstly to his supervisors, Professor H. Fischer and Professor K. Bättig, for their encouragement and criticism throughout the research. Thanks are also due to Professor Klaczko and Dr. H.U. Baumann for their many valuable suggestions, to Laurel Gutmann, Professor A. Flammer and Professor M. Perrez for their many helpful comments on earlier drafts of the paper, and to W.G. Hoffmann and R. Casetti for their further assistance.  相似文献   
1000.
The combined research of Horner (1972) and Monahan, Kuhn, and Shaver (1974) has demonstrated the existence of a stereotype of the female medical student as sex-role deviant and disinterested in sex. The present study examined the validity of this stereotype. Male and female medical students' scores on two psychometric measures were compared with the male and female college norms. The stereotype was not supported. Female medical students demonstrated no greater sex-role deviance than did their male counterparts. Furthermore, only male medical students indicated significantly less heterosexual interest than their same-sex norm.The authors wish to thank Dr. David G. Fish, who was involved in the original data collection. Support for the analyses of these data was obtained from Grant Number 607-1034-21 and from a Career Scientist Award, Number 607-1001-22, to the Junior Author.  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