全文获取类型
收费全文 | 21775篇 |
免费 | 910篇 |
国内免费 | 13篇 |
出版年
2020年 | 254篇 |
2019年 | 244篇 |
2018年 | 422篇 |
2017年 | 362篇 |
2016年 | 391篇 |
2015年 | 254篇 |
2014年 | 360篇 |
2013年 | 1573篇 |
2012年 | 629篇 |
2011年 | 678篇 |
2010年 | 367篇 |
2009年 | 442篇 |
2008年 | 597篇 |
2007年 | 593篇 |
2006年 | 548篇 |
2005年 | 484篇 |
2004年 | 464篇 |
2003年 | 452篇 |
2002年 | 419篇 |
2001年 | 797篇 |
2000年 | 794篇 |
1999年 | 587篇 |
1998年 | 234篇 |
1997年 | 213篇 |
1993年 | 192篇 |
1992年 | 484篇 |
1991年 | 424篇 |
1990年 | 486篇 |
1989年 | 408篇 |
1988年 | 384篇 |
1987年 | 366篇 |
1986年 | 389篇 |
1985年 | 443篇 |
1984年 | 338篇 |
1983年 | 284篇 |
1982年 | 219篇 |
1979年 | 323篇 |
1978年 | 257篇 |
1977年 | 204篇 |
1976年 | 199篇 |
1975年 | 301篇 |
1974年 | 345篇 |
1973年 | 352篇 |
1972年 | 274篇 |
1971年 | 242篇 |
1970年 | 208篇 |
1969年 | 228篇 |
1968年 | 288篇 |
1967年 | 251篇 |
1966年 | 273篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
111.
A general model is developed for the analysis of multivariate multilevel data structures. Special cases of the model include repeated measures designs, multiple matrix samples, multilevel latent variable models, multiple time series, and variance and covariance component models.We would like to acknowledge the helpful comments of Ruth Silver. We also wish to thank the referees for helping to clarify the paper. This work was partly carried out with research funds provided by the Economic and Social Research Council (U.K.). 相似文献
112.
Body-frame size is an important factor in determining an optimal body weight for a given height. Previous studies have indicated that many individuals incorrectly estimate their body-frame size, and, as a result, incorrectly assess their ideal weight. The present study investigated the accuracy of estimation of body-frame size as a function of sex and actual frame size. The subjects were 66 men and 52 women participating in a community adult fitness program. Data indicated that medium-framed individuals were the most accurate in their estimations of body-frame size. Also, women were twice as likely to be accurate as were men. These results are interpreted to mean that most people assume they are medium-framed and that there is a sex difference in the way body-frame size is estimated. 相似文献
113.
Light-eyed individuals generally perform better at self-paced activities while dark-eyed individuals perform better at reactive activities. Using multiple regression it was found that dark-eyed students hit a target with a frisbee more times than did light-eyed students. 相似文献
114.
115.
P Brodsky 《Perceptual and motor skills》1988,66(2):383-386
The youngest subject (age 5) participating in the 1986 evaluation studies published in this Journal returned 25 mo. after finishing REHABIT training. This boy's test scores showed a significant decline in verbal ability. It was concluded that follow-up studies of REHABIT clients are necessary and that such clients should be cautioned that regression may occur. 相似文献
116.
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
117.
118.
"Abnormal fusion" of stereopsis and binocular rivalry 总被引:1,自引:0,他引:1
119.
120.
Practice in front of a mirror is a common procedure for activities such as dance, gymnastics, and other sports. The purpose of this study was to examine the effect that performing with concurrent visual feedback from a mirror had on the acquisition of the power clean movement. 18 college-age males who had no prior experience with the power clean movement served as subjects who were assigned to one of two groups. One group had use of a mirror during the practice trials and the other practiced without the mirror. All subjects viewed an instructional videotape and had practice trials. All subjects were evaluated for proper technique on a pretest, a posttest without the mirror, and a posttest with the mirror. Analysis showed a significant difference between pre- and posttest performances for both groups and a significant difference between groups on the posttest performances with the mirror. Evidently the videotaped instruction was sufficient to allow both groups to improve in performance of the power clean. Differences in posttest performances with the mirror reflected the type of feedback (with or without the mirror) available during training. 相似文献