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   61140篇
  免费   2515篇
  国内免费   33篇
  63688篇
  2020年   692篇
  2019年   855篇
  2018年   1253篇
  2017年   1236篇
  2016年   1302篇
  2015年   888篇
  2014年   1073篇
  2013年   5211篇
  2012年   1932篇
  2011年   2106篇
  2010年   1233篇
  2009年   1221篇
  2008年   1883篇
  2007年   1836篇
  2006年   1629篇
  2005年   1467篇
  2004年   1432篇
  2003年   1303篇
  2002年   1342篇
  2001年   2059篇
  2000年   1950篇
  1999年   1473篇
  1998年   755篇
  1997年   641篇
  1996年   598篇
  1995年   586篇
  1994年   558篇
  1993年   594篇
  1992年   1169篇
  1991年   1119篇
  1990年   1113篇
  1989年   999篇
  1988年   977篇
  1987年   953篇
  1986年   944篇
  1985年   996篇
  1984年   808篇
  1983年   675篇
  1982年   561篇
  1979年   780篇
  1978年   571篇
  1975年   706篇
  1974年   752篇
  1973年   758篇
  1972年   668篇
  1971年   593篇
  1969年   538篇
  1968年   691篇
  1967年   648篇
  1966年   591篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
211.
We studied the correlation of one measure of imagery ability, the Visual Elaboration Scale, with two others, absorption of image and effort required to form a mental image. Significant correlations were obtained between the Visual Elaboration Scale and the other scales, with the exception of Absorption for women.  相似文献   
212.
213.
MMPI profiles of 22 chronic arthritic patients were compared to 22 control pain (nonorganic) patients. While elevations were noted in the HS, D, and Hy scales for the rheumatoid patients, the over-all profiles differed from controls on the PA scale.  相似文献   
214.
Under simple- and choice-RT conditions, the biceps brachii muscle was examined in 8 healthy male subjects to determine how the temporal and spatial characteristics of elbow flexion and forearm supination differed at the initial phase of EMG activity and whether preparation or the presence of response uncertainty influenced the EMG outputs of the two movements. In the simple-RT condition, RT of supination was significantly faster than that of flexion but EMG activity of supination was less than that of flexion. In contrast, in the choice-RT condition, RT of flexion was significantly faster than that of supination but EMG activity of flexion was significantly reduced compared to supination. These findings indicate that advanced preparation or motor set facilitates the differentiation of RTs and EMG activities of the response movements and that response uncertainty causes a significant change in the temporal and spatial specificity of both elbow flexion and forearm supination.  相似文献   
215.
This paper gives a method for determining a sample size that will achieve a prespecified bound on confidence interval width for the interrater agreement measure,. The same results can be used when a prespecified power is desired for testing hypotheses about the value of kappa. An example from the literature is used to illustrate the methods proposed here.  相似文献   
216.
217.
We prove that there are two involutions defined by monadic terms that characterize Monadic Algebras. We further prove that the variety of Monadic Algebras is the smallest variety of Interior Algebras where these involutions give rise to an interpretation from the variety of Bounded Distributive Lattices into it.Research funded by Fondecyt, project N 764-1987.  相似文献   
218.
We obtain in this paper a representation of the formulae of extensions ofL by generalized quantifiers through functors between categories of first-order structures and partial isomorphisms. The main tool in the proofs is the back-and-forth technique. As a corollary we obtain the Caicedo's version of Fraïssés theorem characterizing elementary equivalence for such languages. We also discuss informally some geometrical interpretations of our results.  相似文献   
219.
220.
It has been proposed that a principal cause of the agrammatism of some Broca's aphasics is that such patients, unlike normal subjects, are unable to make use of a special retrieval mechanism for closed-class ("function") words (D. C. Bradley, 1978, Computational distinctions of vocabulary type, Unpublished Ph.D. thesis; D. C. Bradley, M. F. Garrett, & E. B. Zurif, 1980. In D. Caplan (Ed.), Biological studies of mental processes). The main evidence for the existence of such a mechanism consisted of two observations: (1) the recognition of open-class words was observed to be frequency-sensitive, but that of closed-class words was not; and (2) lexical decisions for nonwords which began with open-class words were delayed, whereas there was no such interference for nonwords which began with closed-class words. However, the first of these observations has proved nonreplicable (e.g., B. Gordon & A. Caramazza, 1982, Brain and Language, 15, 143-160, 1983, Brain and Language, 19, 335-345; J. Segui, J. Mehler, W. Frauenfelder, & J. Morton, 1982, Neuropsychologia, 20, 615-627), and in the present paper, three lexical decision experiments are reported in which it is found that, when certain confounding variables are controlled, nonwords which begin with closed-class words are subject to interference. Moreover, contrary to a suggestion of Kolk and Blomert (1985, Brain and Language, 26, 94-105) the interference is independent of the presence of closed-class items in the lexical decision word list. It seems, then, that closed-class words are not qualitatively different from open-class words with respect either to frequency sensitivity or to nonword interference, and in consequence, the above proposed explanation of agrammatism is left without major empirical support.  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