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   20490篇
  免费   18篇
  2020年   5篇
  2018年   3487篇
  2017年   2821篇
  2016年   2247篇
  2015年   190篇
  2014年   80篇
  2013年   67篇
  2012年   559篇
  2011年   2379篇
  2010年   2515篇
  2009年   1469篇
  2008年   1696篇
  2007年   2168篇
  2006年   23篇
  2005年   207篇
  2004年   160篇
  2003年   116篇
  2002年   66篇
  2001年   28篇
  2000年   52篇
  1999年   16篇
  1998年   23篇
  1997年   19篇
  1996年   9篇
  1994年   8篇
  1993年   5篇
  1992年   2篇
  1990年   10篇
  1989年   2篇
  1988年   4篇
  1987年   5篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1983年   6篇
  1982年   8篇
  1981年   2篇
  1980年   2篇
  1979年   2篇
  1978年   6篇
  1977年   2篇
  1976年   4篇
  1975年   6篇
  1974年   2篇
  1970年   2篇
  1969年   2篇
  1968年   3篇
  1967年   3篇
  1962年   2篇
  1952年   2篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
21.
22.
A comparison was made of the runway behaviour of rats which had been handled from Days 1-21 and their non-handled litter mates. The training began on Day 70 after the animals were habituated to a restricted food schedule for 10 days. The subjects were given six trials each day in the runway and were rewarded with a 0.045 g. Noyes pellet. After 10 days of rewarded training trials, subjects were given 6 extinction trials a day for 10 days. Results showed that handled rats ran faster than non-handled rats during acquisition and during the first 3 days of extinction. The extinction data suggested that the relationship between emotionality and effects of frustrative non-reward should be re-evaluated.  相似文献   
23.
For the case of two or more groups of variables (batteries), generalizations on three common factor models, the Equal Residual Variances model, the Image model of Jöreskog, and the Canonical Factor Analysis model, are described and illustrated with empirical examples.The author is indebted to Dr. E. J. Burr for his valuable criticisms.  相似文献   
24.
A general formulation of the latent structure principle is suggested, from which it is possible to derive Lazarsfeld's accounting equations in their most general form. The basic equations of Gibson's latent profile model can thence be derived in a single step.  相似文献   
25.
Four least-squares methods for constructing factor scores have been described in the literature. The formal properties of these scores are developed, and they are compared in terms of four generally desirable properties of constructed factor scores. In particular, it is shown that two of the methods yield scores that are conditionally unbiassed, and univocal in the sense of Guilford and Michael, though not orthogonal, while one of the other methods yields orthogonal scores.It is shown that constructed factor scores cannot be simultaneously univocal and orthogonal, unless we choose the special basis in factor space given by Canonical Factor Analysis.The general problem of choosing between the methods is discussed, on the basis of the theoretical relations obtained.EDITOR'S NOTE: The reader will quickly discover that this article develops several of the generalizations given in the second part of the preceding article, On Factors and Factor Scores. Independent development of the same generalizations is, of course, not a new phenomenon. Because the Presidential Address automatically is accepted for publication and given space in the December issue, it was decided that the only fair thing to do was to print this article in the same issue.  相似文献   
26.
The basic concepts of nonlinear factor analysis are introduced and some extensions of the general theory are developed. An elementary account of the class of multiple-factor polynomial models is presented, using more elementary algebraic methods than have been employed in earlier accounts of this theory. Working formulas are developed for the multiple-factor polynomial model without product terms.Some empirical results are presented.This work was carried out while the author was a Visiting Research Fellow at the Educational Testing Service, Princeton, N. J. It made use of computer facilities at Princeton University that are supported in part by National Science Foundation Grant NSF-Gp579.  相似文献   
27.
28.
The essay examines the argument advanced by E.D. Hirsch, Jr., for instituting ‘cultural literacy’ as a fundamental priority of schools. A number of confusions and equivocations in Hirsch's reasoning are identified, and the propensity of his project to indoctrinate is exposed. Among the features of Hirsch's argument shown to be troubling are his shifting construal of ‘language’, his inconsistency about the requirements of cultural literacy, and his uncritical relation to traditional images of the American past and present. The upshot is to raise the question why Hirsch's project has elicited wide support and praise.  相似文献   
29.
30.
How can we explain that an assertion on something perceived can be understood in the same manner by somebody who cannot perceive that scene? This problem bases the interest in computational linguistics in how listener modeling could possibly be harmonized with reference semantics. Mental images substituting real perception appear as a way out. The architecture of the listener model has to be adapted to the creation and use of such pictorial data structures. Furthermore, the relation between the latter and a verbal (i. e., propositional) representation must be understood. The resulting architecture of a listener model with reference semantics can be employed to solve communicational problems from three general classes in a better way, as is demonstrated by an example implementation.  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