全文获取类型
收费全文 | 25046篇 |
免费 | 457篇 |
国内免费 | 19篇 |
专业分类
教育 | 17973篇 |
科学研究 | 2135篇 |
各国文化 | 276篇 |
体育 | 2118篇 |
综合类 | 14篇 |
文化理论 | 199篇 |
信息传播 | 2807篇 |
出版年
2022年 | 192篇 |
2021年 | 277篇 |
2020年 | 421篇 |
2019年 | 659篇 |
2018年 | 918篇 |
2017年 | 895篇 |
2016年 | 778篇 |
2015年 | 475篇 |
2014年 | 734篇 |
2013年 | 4899篇 |
2012年 | 705篇 |
2011年 | 707篇 |
2010年 | 527篇 |
2009年 | 543篇 |
2008年 | 612篇 |
2007年 | 532篇 |
2006年 | 486篇 |
2005年 | 465篇 |
2004年 | 410篇 |
2003年 | 411篇 |
2002年 | 400篇 |
2001年 | 517篇 |
2000年 | 423篇 |
1999年 | 392篇 |
1998年 | 223篇 |
1997年 | 244篇 |
1996年 | 270篇 |
1995年 | 265篇 |
1994年 | 198篇 |
1993年 | 218篇 |
1992年 | 341篇 |
1991年 | 326篇 |
1990年 | 314篇 |
1989年 | 322篇 |
1988年 | 270篇 |
1987年 | 314篇 |
1986年 | 287篇 |
1985年 | 320篇 |
1984年 | 259篇 |
1983年 | 230篇 |
1982年 | 215篇 |
1981年 | 179篇 |
1980年 | 161篇 |
1979年 | 280篇 |
1978年 | 191篇 |
1977年 | 181篇 |
1976年 | 164篇 |
1975年 | 144篇 |
1974年 | 154篇 |
1971年 | 143篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Newell KM 《Research quarterly for exercise and sport》2003,74(4):383-388
A brief commentary is provided on the theoretical assumptions, scholarly impact and continuing influence of the schema theory of motor learning (Schmidt, 1975). The traditional contrasts of schema theory to the coordinative structure or dynamical systems framework are reemphasized, and limitations of the variability of practice experiments noted. A central problem for theories of motor learning is change over time, the basis on which learning is typically defined. Most theories including schema have, however, undervalued the importance of the time-dependent nature of change in deference to the almost exclusive study of the amount of some averaged change in behavioral outcome. The persistent and transitory change(s) in movement and outcome that are observed in action are reflections of multiple time scales of change in a dynamical system. 相似文献
982.
Clinical librarianship: a systematic review of the literature 总被引:2,自引:2,他引:0
983.
984.
Atlas MC 《Medical reference services quarterly》2001,20(1):11-25
Physicians are becoming aware of the World Wide Web as a resource for medical information. In spring 1999, first-year students at the University of Louisville's School of Medicine were given an assignment to review and evaluate Internet search engines and directories, medicine-specific search engines and meta lists, and health-related Web sites. Students found that general search engines were easier to learn and use and produced better results than either meta medical sites or medicine-specific search engines. Students were very severe in judging the quality of health-related Web sites. Our students' impressions are compared to those of physicians in similar studies. Solutions to the problems of searching the Web for health information are reviewed. 相似文献
985.
986.
The aim of this study was to establish whether asymmetry of the strength of the leg and trunk musculature is more prominent in rowers than in controls. Nineteen oarsmen and 20 male controls matched for age, height and body mass performed a series of isokinetic and isometric strength tests on an isokinetic dynamometer. These strength tests focused on the trunk and leg muscles. Comparisons of strength were made between and within groups for right and left symmetry patterns, hamstring: quadriceps ratios, and trunk flexor and extensor ratios. The results revealed no left and right asymmetries in either the knee extensor or flexor strength parameters (including both isometric and isokinetic measures). Knee extensor strength was significantly greater in the rowing population, but knee flexor strength was similar between the two groups. No difference was seen between the groups for the hamstring: quadriceps strength ratio. In the rowing population, stroke side had no influence on leg strength. No differences were observed in the isometric strength of the trunk flexors and extensors between groups, although EMG activity was significantly higher in the rowing population. Patterns of asymmetry of muscle activity were observed between the left and right erector spinae muscles during extension, which was significantly related to rowing side (P < 0.01). These observations could be related to the high incidence of low back pain in oarsmen. 相似文献
987.
The aim of this study was to determine the influence of type of warm-up on metabolism and performance during high-intensity exercise. Eight males performed 30 s of intense exercise at 120% of their maximal power output followed, 1 min later, by a performance cycle to exhaustion, again at 120% of maximal power output. Exercise was preceded by active, passive or no warm-up (control). Muscle temperature, immediately before exercise, was significantly elevated after active and passive warm-ups compared to the control condition (36.9 +/- 0.18 degrees C, 36.8 +/- 0.18 degrees C and 33.6 +/- 0.25 degrees C respectively; mean +/- sx) (P< 0.05). Total oxygen consumption during the 30 s exercise bout was significantly greater in the active and passive warm-up trials than in the control trial (1017 +/- 22, 943 +/- 53 and 838 +/- 45 ml O2 respectively). Active warm-up resulted in a blunted blood lactate response during high-intensity exercise compared to the passive and control trials (change = 5.53 +/- 0.52, 8.09 +/- 0.57 and 7.90 +/- 0.38 mmol x l(-1) respectively) (P < 0.05). There was no difference in exercise time to exhaustion between the active, passive and control trials (43.9 +/- 4.1, 48.3 +/- 2.7 and 46.9 +/- 6.2 s respectively) (P= 0.69). These results indicate that, although the mechanism by which muscle temperature is elevated influences certain metabolic responses during subsequent high-intensity exercise, cycling performance is not significantly affected. 相似文献
988.
The aim of the present study was to assess the influence of self-efficacy and past behaviour on young people's physical activity intentions using an augmented version of Ajzen's Theory of Planned Behaviour. We hypothesized that self-efficacy would exhibit discriminant validity with perceived behavioural control and explain unique variance in young people's intentions to participate in physical activity. We also expected that past physical activity behaviour would attenuate the influence of attitude, subjective norms, perceived behavioural control and self-efficacy on intention. The sample comprised 1,152 young people aged 13.5 +/- 0.6 years (mean +/- s) who completed inventories assessing their physical activity intentions, attitudes, subjective norms, perceived behavioural control, self-efficacy and past physical activity behaviour. A confirmatory factor analysis demonstrated that the constructs of the Theory of Planned Behaviour achieved discriminant validity. Furthermore, the measures of attitudes, subjective norms, perceived behavioural control and self-efficacy were significantly related to their respective belief-based measures, supporting the concurrent validity of the measures of the Theory of Planned Behaviour. A non-standard structural equation model demonstrated that attitude and self-efficacy were strong predictors of physical activity intention, but perceived behavioural control and subjective norms were not. Self-efficacy attenuated the influence of attitudes and perceived behavioural control on intention. Past behaviour predicted intention directly and indirectly through self-efficacy and attitude. The present findings demonstrate that young people with positive attitudes and high self-efficacy are more likely to form intentions to participate in physical activity. Furthermore, controlling for past physical activity behaviour revealed that the unique effects of self-efficacy and attitudes on young people's physical activity intentions were unaltered. 相似文献
989.
990.
Research into the physiology of exercise and kinanthropometry is intended to improve our understanding of how the body responds and adapts to exercise. If such studies are to be meaningful, they have to be well designed and analysed. Advances in personal computing have made available statistical analyses that were previously the preserve of elaborate mainframe systems and have increased opportunities for investigation. However, the ease with which analyses can be performed can mask underlying philosophical and epistemological shortcomings. The aim of this review is to examine the use of four techniques that are especially relevant to physiological studies: (1) bivariate correlation and linear and non-linear regression, (2) multiple regression, (3) repeated-measures analysis of variance and (4) multi-level modelling. The importance of adhering to underlying statistical assumptions is emphasized and ways to accommodate violations of these assumptions are identified. 相似文献