全文获取类型
收费全文 | 6301篇 |
免费 | 95篇 |
国内免费 | 6篇 |
专业分类
教育 | 4638篇 |
科学研究 | 386篇 |
各国文化 | 100篇 |
体育 | 509篇 |
综合类 | 4篇 |
文化理论 | 107篇 |
信息传播 | 658篇 |
出版年
2023年 | 16篇 |
2022年 | 27篇 |
2021年 | 72篇 |
2020年 | 159篇 |
2019年 | 203篇 |
2018年 | 225篇 |
2017年 | 260篇 |
2016年 | 246篇 |
2015年 | 153篇 |
2014年 | 190篇 |
2013年 | 1338篇 |
2012年 | 183篇 |
2011年 | 199篇 |
2010年 | 158篇 |
2009年 | 154篇 |
2008年 | 187篇 |
2007年 | 181篇 |
2006年 | 153篇 |
2005年 | 165篇 |
2004年 | 139篇 |
2003年 | 142篇 |
2002年 | 130篇 |
2001年 | 107篇 |
2000年 | 108篇 |
1999年 | 69篇 |
1998年 | 67篇 |
1997年 | 87篇 |
1996年 | 88篇 |
1995年 | 61篇 |
1994年 | 76篇 |
1993年 | 64篇 |
1992年 | 78篇 |
1991年 | 61篇 |
1990年 | 63篇 |
1989年 | 51篇 |
1988年 | 60篇 |
1987年 | 44篇 |
1986年 | 55篇 |
1985年 | 61篇 |
1984年 | 59篇 |
1983年 | 60篇 |
1982年 | 47篇 |
1981年 | 40篇 |
1980年 | 41篇 |
1979年 | 45篇 |
1978年 | 47篇 |
1977年 | 29篇 |
1976年 | 25篇 |
1975年 | 18篇 |
1948年 | 18篇 |
排序方式: 共有6402条查询结果,搜索用时 31 毫秒
941.
Michael J. Hiley Roger Wangler Gheorghe Predescu 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):39-51
The felge, or undersomersault, on parallel bars has become an important skill in men's artistic gymnastics as it forms the basis of many complex variations. To receive no deductions from the judges, the felge must be performed without demonstrating the use of strength to achieve the final handstand position. Two male gymnasts each performed nine trials of the felge from handstand to handstand while data were recorded using an automatic motion capture system. The highest and lowest scoring trials of each gymnast, as determined by four international judges, were chosen for further analysis. The technique used by each gymnast was optimized using a computer simulation model so that the final handstand position could be achieved with straight arms. Two separate optimizations found different techniques identified in the coaching literature that are used by gymnasts. Optimum simulations resulted in improved performances through a combination of increased vertical velocity and height of the mass centre at release. Although the optimum technique found close to the gymnasts' own technique was more demanding in terms of the strength required, it offered the potential for more consistent performance and future developments in skill complexity. 相似文献
942.
Andrew J. Greene Michael H. Dickson Floren Colloud Richard M. Smith 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):302-317
The effect of anthropometric differences in shank to thigh length ratio upon timing and magnitude of joint power production during the drive phase of the rowing stroke was investigated in 14 elite male rowers. Rowers were tested on the RowPerfect ergometer which was instrumented at the handle and foot stretcher to measure force generation, and a nine segment inverse dynamics model used to calculate the rower's joint and overall power production. Rowers were divided into two groups according to relative shank thigh ratio. Time to half lumbar power generation was significantly earlier in shorter shank rowers (p = 0.028) compared to longer shank rowers, who showed no lumbar power generation during the same period of the drive phase. Rowers with a relatively shorter shank demonstrated earlier lumbar power generation during the drive phase resulting from restricted rotation of the pelvic segment requiring increased lumbar extension in these rowers. Earlier lumbar power generation and extension did not appear to directly affect performance measures of the short shank group, and so can be attributed to a technical adaptation developed to maximise rowing performance. 相似文献
943.
This case is about Major League Baseball and the Dominican Republic. We explore how Major League Baseball has used this Caribbean island as an inexpensive labor market and the social problems of the situation. Specifically, we examine Corporate Social Responsibility, the leadership of Sandy Alderson, ethics and the various stakeholders involved. We also look into possible reform alternatives while addressing the central question: What is in the best interest of the players? 相似文献
944.
Teaching and learning in digital environments: The resurgence of resource-based learning 总被引:4,自引:0,他引:4
Janette R. Hill Michael J. Hannafin 《Educational technology research and development : ETR & D》2001,49(3):37-52
The digital age has not simply changed the nature of resources and information; it has transformed several basic social and
economic enterprises. Contemporary society—the settings where we live, work, and learn—has likewise changed dramatically.
Both the amount of information and access to it have grown exponentially; a significant potential for using varied resources
in numerous ways for instruction and learning has emerged. However, several issues related to the educational uses of varied
resources (e.g., people, place, things, ideas) must be addressed if we are successfully to implement resource-based learning
environments. In this paper, we trace the changing nature of resources and perspectives in their use for learning in the digital
age, describe the overarching structures of resource-based learning environments, and identify key challenges to be addressed. 相似文献
945.
Since Grossman’s seminal paper in 1972, there have been a number of studies concerning the effect of education on health and health care demand. Though several studies have distinguished between preventive and curative care, no study has investigated the effects of general education on the utilization of unnecessary emergency department use. We test whether general education reduces “potentially unnecessary” emergency department utilization and provide a measure of the resulting private benefits associated with increased education. Our results partially confirm our hypothesis regarding “potentially unnecessary” emergency department use. We find that moving from a high school to greater than high school education appears to reduce “potentially unnecessary” emergency department use, with the impact being greater among the insured. However, though reducing the education level from high school to less than high school increases “potentially unnecessary” emergency department use among the insured as predicted, it has the opposite impact on the uninsured. 相似文献
946.
D. Chris Anderson Charles R. Crowell Michael Depaul John Mceachin 《Learning & behavior》1997,25(1):68-83
Three experiments tested the hypotheses that (1) the onsets of prolonged, fixed-duration treatment shocks (shock treatment, or ST) serve as cues for fear conditioning to the ongoing painful effects of these stimuli, and (2) this acquired fear transfers to and influences shock-motivated test performances in predictable ways. Experiments 1 and 2 involved spaced post-ST presentations of very brief shocks (a presumed analogue of the onsets of treatment shocks) as a means of extinguishing the fear putatively associated with shock cues. This procedure reduced defecation by ST subjects over blocks of extinction sessions and nullified the punishment intensification effect that was otherwise shown to be a consequence of ST. As a further test of the shock-cue hypothesis, Experiment 3 involved relatively massed presentations of these brief shocks prior to ST in a latent-inhibition procedure (Lubow, 1973). This briefshock regimen also nullified the ST punishment intensification effect but did not impair the transituational transfer of contextual fear. In contrast, the group that was given the same brief shock regimen following ST showed enhancement of the punishment effect. With respect to current theoretical accounts of ST effects, these data were most consistent with notions that rely on an acquired-fear construct. 相似文献
947.
This article summarizes a reformulation of the main findings and perspectives from a cross-sectional and longitudinal qualitative study of the development of 100 counselors and therapists. The results are presented as a phase model and as a formulation of 14 themes of counselor/therapist development. The following six phases are described: The phases of the lay helper, the beginning student, the advanced student, the novice professional, the experienced professional, and the senior professional. The themes describe central processes of counselor/therapist development. The themes are addressing different issues such as shifts in attentional focus and emotional functioning, the importance of continuous reflection for professional growth, and a life-long personal/profession integration process. Sources of influence for professional functioning and development are described. The results show consistently that interpersonal experiences in the personal life domain (early family life and adult personal life) and the professional life domain (interacting with clients, professional elders, and peers) are significant sources of influence for professional development. 相似文献
948.
949.
Stephen M. Koziol J. Bradley Minnick Michael A. Sherman 《Journal of Personnel Evaluation in Education》1996,10(1):53-74
Paper presented at the Annual Meeting of the American Educational Research Association, San Francisco, CA. April, 1995 相似文献
950.
This longitudinal study used latent growth curve modeling to investigate English literacy development in a sample of Spanish-speaking language minority students from third through eighth grade. This study also compared the sample’s literacy development to the entire population of California students using state standardized test data. Second, this study examined the contributions of a variety of bilingual measures of kindergarten letter knowledge, phonological awareness, word reading, and vocabulary to literacy development. Results demonstrated the present sample scored below average in literacy compared to the overall population of California students across years, but made slight gains to narrow the achievement gap. The greatest gains were obtained between fourth and fifth grade, but plateaued thereafter. Results concerning the second research questions showed that the third grade literacy intercept was predicted by kindergarten English letter knowledge, Spanish onset, Spanish word reading, and English vocabulary. However, English literacy development through eighth grade was only predicted by kindergarten English and Spanish vocabulary. Findings support arguments for educational efforts to target oral language instruction for these students in early elementary and instruction in both languages may provide the greatest benefit. Instructional implications are discussed. 相似文献