全文获取类型
收费全文 | 21831篇 |
免费 | 870篇 |
国内免费 | 6篇 |
专业分类
22707篇 |
出版年
2019年 | 295篇 |
2018年 | 365篇 |
2017年 | 331篇 |
2016年 | 374篇 |
2015年 | 269篇 |
2014年 | 368篇 |
2013年 | 1781篇 |
2012年 | 627篇 |
2011年 | 695篇 |
2010年 | 421篇 |
2009年 | 435篇 |
2008年 | 552篇 |
2007年 | 574篇 |
2006年 | 556篇 |
2005年 | 448篇 |
2004年 | 478篇 |
2003年 | 439篇 |
2002年 | 443篇 |
2001年 | 641篇 |
2000年 | 698篇 |
1999年 | 489篇 |
1998年 | 256篇 |
1996年 | 212篇 |
1992年 | 384篇 |
1991年 | 391篇 |
1990年 | 393篇 |
1989年 | 367篇 |
1988年 | 348篇 |
1987年 | 324篇 |
1986年 | 338篇 |
1985年 | 351篇 |
1984年 | 278篇 |
1983年 | 276篇 |
1982年 | 205篇 |
1981年 | 201篇 |
1980年 | 210篇 |
1979年 | 351篇 |
1978年 | 270篇 |
1977年 | 196篇 |
1976年 | 208篇 |
1975年 | 286篇 |
1974年 | 336篇 |
1973年 | 356篇 |
1972年 | 293篇 |
1971年 | 283篇 |
1970年 | 235篇 |
1969年 | 270篇 |
1968年 | 313篇 |
1967年 | 318篇 |
1966年 | 255篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
S Martin K Housley H Mccoy P Greenhouse F Stigger M A Kenney S Shoffner V Fu M Korslund F G Ercanli-Huffman 《Perceptual and motor skills》1988,67(3):879-884
The Rosenberg Self-esteem Scale was administered to 550 14- and 16-yr.-old (+/- 6 mo.) girls. Self-esteem scores were categorized by weight and weight by height. Scores on the Quetelet Index for obesity were correlated with self-esteem scores. Mean self-esteem of the low- and middle-weight by height group was significantly higher than the mean of the high-weight by height group. In analyzing weight alone, the self-esteem of the middle-weight group was significantly higher than the self-esteem of the high-weight group. The correlation of the obesity index and self-esteem indicated that as weight increased self-esteem decreased. 相似文献
62.
S W?sser W Handrick F B Spencker W Braun 《Psychiatrie, Neurologie, und medizinische Psychologie》1988,40(2):95-101
Observations on three children with neurolisteriosis (one case of meningitis, two cases of meningoencephalitis, each Serovar 4 b), show that even after the neonatal period, listeriosis must not be ignored in the process of diagnosis and therapy. It is the bacteriological examination of the cerebrospinal fluid, together with the blood culture, and not clinical symptoms and serology that guarantee a timely diagnosis and therapy (ampicillin and gentamicin). 相似文献
63.
64.
65.
66.
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
67.
Jos M. F. ten Berge 《Psychometrika》1988,53(4):487-494
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
68.
J M McDowd F I Craik 《Journal of experimental psychology. Human perception and performance》1988,14(2):267-280
We report two experiments that compare the performance of young and older adults on perceptual-motor tasks involving division of attention. Previous studies have shown older people to be especially penalized by divided attention situations, but the generality of this finding was recently challenged by Somberg and Salthouse (1982). The present study was conducted to investigate the possibility that age differences in dual-task performance are amplified by an increase in the difficulty of the constituent tasks, where difficulty was manipulated by varying the central, cognitive nature of the tasks (Experiment 1) or the degree of choice involved (Experiment 2). With the present tasks, strong evidence was found for an age-related decrement in divided attention performance. Contrary to our original expectations, however, it does not seem that division of attention presents some especial difficulty to older people. Rather, division of attention is one of several equivalent ways to increase overall task complexity. In turn, age differences are exaggerated as tasks are made more complex. 相似文献
69.
S-R compatibility between response position and destination of apparent motion: evidence of the detection of affordances 总被引:2,自引:0,他引:2
C F Michaels 《Journal of experimental psychology. Human perception and performance》1988,14(2):231-240
In choice reaction time, stimuli and responses in some combinations (e.g., based on spatial arrangement) are faster than in other combinations. To test whether motion toward a position yields faster responses at that position, a computer-generated square in front of one hand appeared to move either toward that hand or toward the other hand. Compatible responses (e.g., motion toward left hand/left response) were faster than incompatible responses, even when that opposed traditional positional compatibility. In Experiment 2, subjects responded to the same stimuli but with both hands left, right, or on the body midline. Medial responses were the fastest, showing that destination, rather than mere relative position, was a critical variable. It was suggested that spatial compatibility effects are not unique to position but apply to a variety of task situations, describable by J.J. Gibson's theory of affordances, in which he claims that one perceives the actions (e.g., catching) permitted in a situation. 相似文献
70.