全文获取类型
收费全文 | 21204篇 |
免费 | 930篇 |
国内免费 | 9篇 |
出版年
2020年 | 239篇 |
2019年 | 260篇 |
2018年 | 372篇 |
2017年 | 351篇 |
2016年 | 389篇 |
2015年 | 307篇 |
2014年 | 367篇 |
2013年 | 1614篇 |
2012年 | 678篇 |
2011年 | 653篇 |
2010年 | 438篇 |
2009年 | 401篇 |
2008年 | 550篇 |
2007年 | 566篇 |
2006年 | 506篇 |
2005年 | 470篇 |
2004年 | 420篇 |
2003年 | 380篇 |
2002年 | 418篇 |
2001年 | 858篇 |
2000年 | 831篇 |
1999年 | 585篇 |
1998年 | 217篇 |
1997年 | 206篇 |
1996年 | 207篇 |
1992年 | 468篇 |
1991年 | 442篇 |
1990年 | 450篇 |
1989年 | 383篇 |
1988年 | 369篇 |
1987年 | 366篇 |
1986年 | 346篇 |
1985年 | 355篇 |
1984年 | 320篇 |
1983年 | 270篇 |
1982年 | 202篇 |
1979年 | 324篇 |
1978年 | 225篇 |
1977年 | 195篇 |
1976年 | 188篇 |
1975年 | 265篇 |
1974年 | 326篇 |
1973年 | 315篇 |
1972年 | 253篇 |
1971年 | 255篇 |
1970年 | 219篇 |
1969年 | 251篇 |
1968年 | 281篇 |
1967年 | 276篇 |
1966年 | 205篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
The three reliability and two construct validity studies presented here represent the first psychometric research on the commercially successful and popular Hartman Color Code Personality Profile. The reliability studies found high reliability after 3 and 6 weeks. The construct validity studies substantiated that the Color Code assesses some personality traits. The magnitude of the error variance suggests caution, however, in using the Color Code classifications at the individual level. 相似文献
12.
13.
Linda J Koenig Sherri L Pals Tim Bush Melody Pratt Palmore Dale Stratford Tedd V Ellerbrock 《Health psychology》2008,27(2):159-169
OBJECTIVE: Compare the efficacy of a multicomponent social support intervention to standard-of-care counseling on medication adherence among HIV-infected patients initiating antiretroviral therapy. DESIGN: Randomized controlled trial. Generalized estimating equations tested for differences in the percentage of participants achieving 90% adherence. MAIN OUTCOME MEASURES: Pill-taking, electronically monitored over 6 consecutive months; plasma viral load (VL), assessed at 3 and 6 months following initiation of therapy. RESULTS: Of 226 participants who were randomized and began the trial, 87 (38%) were lost to the study by 6 months. The proportion of adherent participants declined steadily over time, with no time by group interaction. Sustained adherence was associated with increased odds of achieving an undetectable VL (OR=1.78; 95% CI=1.01, 3.13). In intention-to-treat analyses, a larger proportion of the intervention group than the control group was adherent (40.15% vs. 27.59%, p=.02) and achieved an undetectable VL p=.04). However, the majority of participants who remained on study experienced some reduction in VL (>or=1-log drop or undetectable), regardless of experimental condition. CONCLUSION: The multicomponent social support intervention significantly improved medication adherence over standard-of-care counseling; evidence for improved virologic outcomes was inconsistent. Early discontinuation of care and treatment may be a greater threat to the health of HIV patients than imperfect medication-taking. 相似文献
14.
15.
16.
17.
The ability to make egocentric distance estimates of a single point source of light, seen in darkness and without the cues of changing size and luminance, was investigated in sixteen observers. The attenuation required to maintain constant luminance, when the target was viewed from different distances, was shown to follow the inverse square law providing the angle subtended by the light was less than 20 s arc. Distance changes were also simulated by means of a split mirror which produced vergence cues, or by test lenses to provide accommodation cues. Over the range 0.5 to 9.2 m distance estimates were surprisingly accurate, although there was some overestimation of near and underestimation of far distances. Most observers made good judgements when only convergence cues were varied, whereas no observers made consistently good judgements when only accommodation cues were varied. The difficulties are discussed in terms of the accommodation-convergence link. When distance was simulated by changing convergence and accommodation cues, estimates were not as good as when real distance was changed. Since good estimates were made with brief target exposures, these judgements were not based on subsequent convergence or accommodation changes. It is suggested that the metric or reference against which the apparently absolute judgements were made was the efferent demand signal associated with a 'resting' position of convergence in darkness. 相似文献
18.
T. J. Roper R. A. Boakes 《The Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology》1981,33(2):137-140
TOATES, F. Animal Behaviour: A Systems Approach. Chichester: John Wiley and Sons. 1980. Pp. 299. Hardback £17. Paper back £6.40 ISBN 0 471 27724.
DICKINSON, A. Contemporary Animal Learning Theory. Cambridge: University Press. 1980. Pp. 177. Hardback £12.50. Paperback £3.95. ISBN 0 521 23469 7. 相似文献
DICKINSON, A. Contemporary Animal Learning Theory. Cambridge: University Press. 1980. Pp. 177. Hardback £12.50. Paperback £3.95. ISBN 0 521 23469 7. 相似文献
19.
20.