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   2354篇
  免费   124篇
  国内免费   1篇
  2024年   5篇
  2023年   27篇
  2022年   16篇
  2021年   45篇
  2020年   56篇
  2019年   58篇
  2018年   93篇
  2017年   89篇
  2016年   91篇
  2015年   67篇
  2014年   83篇
  2013年   360篇
  2012年   180篇
  2011年   174篇
  2010年   99篇
  2009年   69篇
  2008年   159篇
  2007年   152篇
  2006年   121篇
  2005年   76篇
  2004年   46篇
  2003年   52篇
  2002年   53篇
  2001年   17篇
  2000年   35篇
  1999年   21篇
  1998年   21篇
  1997年   16篇
  1996年   15篇
  1995年   13篇
  1994年   20篇
  1993年   6篇
  1992年   11篇
  1991年   17篇
  1990年   9篇
  1989年   13篇
  1988年   9篇
  1987年   6篇
  1986年   4篇
  1985年   3篇
  1984年   11篇
  1983年   6篇
  1982年   4篇
  1981年   3篇
  1980年   4篇
  1979年   6篇
  1977年   6篇
  1975年   4篇
  1974年   4篇
  1973年   3篇
排序方式: 共有2479条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Van de Geer has reviewed various criteria for transforming two or more matrices to maximal agreement, subject to orthogonality constraints. The criteria have applications in the context of matching factor or configuration matrices and in the context of canonical correlation analysis for two or more matrices. The present paper summarizes and gives a unified treatment of fully general computational solutions for two of these criteria, Maxbet and Maxdiff. These solutions will be shown to encompass various well-known methods as special cases. It will be argued that the Maxdiff solution should be preferred to the Maxbet solution whenever the two criteria coincide. Horst's Maxcor method will be shown to lack the property of monotone convergence. Finally, simultaneous and successive versions of the Maxbet and Maxdiff solutions will be treated as special cases of a fully flexible approach where the columns of the rotation matrices are obtained in successive blocks.The author is obliged to Henk Kiers for computational assistance and helpful comments.  相似文献   
5.
The present research investigated in a dual task design the effects of extraversion level and structural task properties on the recall of an incidentally learned text. First, the hypothetical relation between arousal level and attentional selectivity was tested. Second, the relation between structural levels in the text and recall of text elements was studied. It was found that (a) extraverts performed significantly better on incidental recall compared to introverts; (b) the nuclear sentences at the top of the hierarchical structure were the best recalled sentences, independently of arousal level; (c) the effect of differences in arousal on recall was only significant in case of the top sentences. The effect was absent in case of specificúsecondary sentences.  相似文献   
6.
Previous research has shown that harmony-enhancing procedures for conflict resolution are endorsed more in collectivist than in individualist societies, whereas the reverse is true for confrontational procedures. However, this result is derived from comparing Western with Eastern societies, leaving the possibility that it may be caused by a variety of East—West differences other than collectivism and individualism. To resolve this ambiguity and to extend the generality of this finding, two collectivist societies, one from Europe (Spain) and the other one from Asia (Japan), were contrasted in the present study. Consistent with the individualism—collectivism framework, results indicated that the procedural preferences of these two cultural groups were quite similar. Results also indicated that expectancies based on process control and animosity reduction were culture-general predictors of procedural preference, and that valences based on these variables yielded little additional variance over and above the expectancy variables. Expectancies based on fairness and favourableness were found to be culture-specific, as were their relationships with procedural preference. Results also implied that cultural femininity was not related to procedural preference. Finally, implications of these results for developing a universal theory of procedural preference are discussed.  相似文献   
7.
Summary Many studies have shown that in a simple reaction-time (RT) task a non-informative leading cue decreases RT to a subsequent target presented in the same region as the cue. This facilitation lasts about 150 ms; it is then replaced by a sustained inhibition. Experiment 1 tests the hypothesis that the initial facilitation is due to motor, rather than perceptual, processes by using choice RT. Facilitation is greater and lasts longer in choice than in simple tasks, thus supporting the hypothesis. Experiment 2 shows that facilitation occurs even when the subject actively orients his or her attention away from the cue.  相似文献   
8.
Millsap and Meredith (1988) have developed a generalization of principal components analysis for the simultaneous analysis of a number of variables observed in several populations or on several occasions. The algorithm they provide has some disadvantages. The present paper offers two alternating least squares algorithms for their method, suitable for small and large data sets, respectively. Lower and upper bounds are given for the loss function to be minimized in the Millsap and Meredith method. These can serve to indicate whether or not a global optimum for the simultaneous components analysis problem has been attained.Financial support by the Netherlands organization for scientific research (NWO) is gratefully acknowledged.  相似文献   
9.
An algorithm is presented for the best least-squares fitting correlation matrix approximating a given missing value or improper correlation matrix. The proposed algorithm is based upon a solution for Mosier's oblique Procrustes rotation problem offered by ten Berge and Nevels. A necessary and sufficient condition is given for a solution to yield the unique global minimum of the least-squares function. Empirical verification of the condition indicates that the occurrence of non-optimal solutions with the proposed algorithm is very unlikely. A possible drawback of the optimal solution is that it is a singular matrix of necessity. In cases where singularity is undesirable, one may impose the additional nonsingularity constraint that the smallest eigenvalue of the solution be , where is an arbitrary small positive constant. Finally, it may be desirable to weight the squared errors of estimation differentially. A generalized solution is derived which satisfies the additional nonsingularity constraint and also allows for weighting. The generalized solution can readily be obtained from the standard unweighted singular solution by transforming the observed improper correlation matrix in a suitable way.  相似文献   
10.
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