全文获取类型
收费全文 | 1561篇 |
免费 | 59篇 |
出版年
2019年 | 23篇 |
2018年 | 23篇 |
2017年 | 29篇 |
2016年 | 32篇 |
2015年 | 27篇 |
2014年 | 24篇 |
2013年 | 158篇 |
2012年 | 38篇 |
2011年 | 38篇 |
2010年 | 27篇 |
2009年 | 37篇 |
2008年 | 64篇 |
2007年 | 57篇 |
2006年 | 45篇 |
2005年 | 63篇 |
2004年 | 54篇 |
2003年 | 52篇 |
2002年 | 45篇 |
2001年 | 46篇 |
2000年 | 27篇 |
1999年 | 27篇 |
1998年 | 28篇 |
1997年 | 29篇 |
1996年 | 26篇 |
1995年 | 19篇 |
1994年 | 18篇 |
1993年 | 19篇 |
1992年 | 16篇 |
1991年 | 27篇 |
1990年 | 26篇 |
1989年 | 21篇 |
1988年 | 15篇 |
1987年 | 25篇 |
1986年 | 15篇 |
1985年 | 16篇 |
1984年 | 22篇 |
1983年 | 18篇 |
1982年 | 33篇 |
1981年 | 17篇 |
1980年 | 18篇 |
1979年 | 18篇 |
1978年 | 20篇 |
1977年 | 17篇 |
1976年 | 18篇 |
1975年 | 17篇 |
1974年 | 22篇 |
1973年 | 21篇 |
1972年 | 19篇 |
1968年 | 17篇 |
1967年 | 13篇 |
排序方式: 共有1620条查询结果,搜索用时 15 毫秒
431.
In Experiment 1, 15 skilled and 15 less skilled participants performed 1-handed catching in 4 conditions. For both groups, catching performance deteriorated significantly when no visual information was available for 40 ms between 20-ms visual samples (20/40) and continued to decline with subsequent increases in the duration between visual samples (i.e., 20/80 and 20/120). In Experiment 2, 50 participants performed a pretest and a posttest in a 20/80 condition, separated by 4 blocks of practice (N=80). Participants who practiced with intermittent vision (20/40, 20/80, and 20/120) exhibited a significant improvement between pretest and posttest. Although general practice with intermittent vision enabled some adaptation, posttest performance did not equal performance in the 1st block of continuous vision. 相似文献
432.
After observers see an object or pattern, their visual memory of what they have seen decays slowly over time. Nearly all current theories of vision assume that decay of short-term memory occurs because visual representations are progressively and randomly corrupted as time passes. We tested this assumption using psychophysical noise-masking methods, and we found that visual memory decays in a completely deterministic fashion. This surprising finding challenges current ideas about visual memory and sets a goal for future memory research: to characterize the deterministic "forgetting function" that describes how memories decay over time. 相似文献
433.
The mediating role of self-efficacy in the development of entrepreneurial intentions 总被引:4,自引:0,他引:4
The purpose of this study was to investigate the mediating role of self-efficacy in the development of students' intentions to become entrepreneurs. The authors used structural equation modeling with a sample of 265 master of business administration students across 5 universities to test their hypotheses. The results showed that the effects of perceived learning from entrepreneurship-related courses, previous entrepreneurial experience, and risk propensity on entrepreneurial intentions were fully mediated by entrepreneurial self-efficacy. Contrary to expectations, gender was not mediated by self-efficacy but had a direct effect such that women reported lower entrepreneurial career intentions. The authors discuss practical implications and directions for future research. 相似文献
434.
In the pursuit of researches and in the reporting of their results, the individual scientist as well as the community of fellow
professionals rely implicitly on the researcher embracing the habit of truthfulness, a main pillar of the ethos of science.
Failure to adhere to the twin imperatives of candor and integrity will be adjudged intolerable and, by virtue of science’s
self-policing mechanisms, rendered the exception to the rule. Yet both as philosophical concepts and in practice, candor and
integrity are complex, difficult to define clearly, and difficult to convey easily to those entering on scientific careers.
Therefore it is useful to present operational examples of two major scientists who exemplified devotion to candor and integrity
in scientific research. 相似文献
435.
Decline in explicit memory with advancing age is a common finding, but it is unclear whether implicit memory (repetition priming) declines or remains stable. Meta-analyses of studies that examined differences between extreme groups (young-old), typically at a single point in time and on a single test, suggest that a mild reduction in priming occurs with advancing age. The authors examined explicit memory and priming, on multiple tests over 4 annual data-collection waves, in a large group of older persons without dementia at baseline. Explicit memory declined significantly, but priming remained stable. Findings indicate that explicit memory and priming are dissociable on the basis of age-related change and that mildly reduced priming is not an inevitable consequence of growing older. 相似文献
436.
437.
A thorough understanding of Multiple Sclerosis (MS) is necessary to offer individuals informed options for treatment and planning. To assist in this quest, the following historical analysis examined how MS has been conceived from the 14th century through the early 20th century. Primary sources were consulted whenever possible, and many of the original archival materials were accessed by the first author (MB) during an on-site visit to the Rare Book Room of the New York Academy of Medicine. There is a striking similarity between how MS symptoms have presented throughout history compared with the 21st century. Sensorimotor and cognitive sequelae have been observed in patients since the 1800s. Cognitive symptoms were acknowledged in the 1800s, but disregarded in the early 1900s and were not given recognition again until the latter part of the 20th century. If conceptualizations of MS are inaccurate, patients will not be served well. In contrast to the shared symptomatology across time, early conceptualizations of etiology and treatment choices differed dramatically from today, a genuine reflection of the times in which they were created. 相似文献
438.
Effectiveness of training in organizations: a meta-analysis of design and evaluation features 总被引:2,自引:0,他引:2
The authors used meta-analytic procedures to examine the relationship between specified training design and evaluation features and the effectiveness of training in organizations. Results of the meta-analysis revealed training effectiveness sample-weighted mean ds of 0.60 (k = 15, N = 936) for reaction criteria, 0.63 (k = 234, N = 15,014) for learning criteria, 0.62 (k = 122, N = 15,627) for behavioral criteria, and 0.62 (k = 26, N = 1,748) for results criteria. These results suggest a medium to large effect size for organizational training. In addition, the training method used, the skill or task characteristic trained, and the choice of evaluation criteria were related to the effectiveness of training programs. Limitations of the study along with suggestions for future research are discussed. 相似文献
439.
Schmitt DP Alcalay L Allik J Ault L Austers I Bennett KL Bianchi G Boholst F Cunen MA Braeckman J Brainerd EG Caral LG Caron G Casullo MM Cunningham M Daibo I De Backer C De Souza E Diaz-Loving R Diniz G Durkin K Echegaray M Eremsoy E Euler HA Falzon R Fisher ML Foley D Fry DP Fry S Ghayur MA Golden DL Grammer K Grimaldi L Halberstadt J Herrera D Hertel J Hoffmann H Hooper D Hradilekova Z Hudek-Kene-evi J Jaafer J Jankauskaite M Kabangu-Stahel H Kardum I Khoury B Kwon H Laidra K Laireiter AR 《Journal of personality and social psychology》2003,85(1):85-104
Evolutionary psychologists have hypothesized that men and women possess both long-term and short-term mating strategies, with men's short-term strategy differentially rooted in the desire for sexual variety. In this article, findings from a cross-cultural survey of 16,288 people across 10 major world regions (including North America, South America, Western Europe, Eastern Europe, Southern Europe, Middle East, Africa, Oceania, South/Southeast Asia, and East Asia) demonstrate that sex differences in the desire for sexual variety are culturally universal throughout these world regions. Sex differences were evident regardless of whether mean, median, distributional, or categorical indexes of sexual differentiation were evaluated. Sex differences were evident regardless of the measures used to evaluate them. Among contemporary theories of human mating, pluralistic approaches that hypothesize sex differences in the evolved design of short-term mating provide the most compelling account of these robust empirical findings. 相似文献
440.
Using WHO data from 1996 instead of 1990, the authors replicated and extended Knodrichin and Lester's 2001 study. Like their study, our total rates of cancer mortality and suicide in a similar sample of 37 European nations of the world were estimated to be positively associated. 相似文献