全文获取类型
收费全文 | 4284篇 |
免费 | 370篇 |
国内免费 | 2篇 |
专业分类
教育 | 3995篇 |
科学研究 | 49篇 |
各国文化 | 114篇 |
体育 | 134篇 |
文化理论 | 30篇 |
信息传播 | 334篇 |
出版年
2021年 | 38篇 |
2020年 | 59篇 |
2019年 | 131篇 |
2018年 | 134篇 |
2017年 | 184篇 |
2016年 | 124篇 |
2015年 | 179篇 |
2014年 | 196篇 |
2013年 | 1241篇 |
2012年 | 161篇 |
2011年 | 180篇 |
2010年 | 182篇 |
2009年 | 165篇 |
2008年 | 195篇 |
2007年 | 124篇 |
2006年 | 111篇 |
2005年 | 102篇 |
2004年 | 99篇 |
2003年 | 53篇 |
2002年 | 54篇 |
2001年 | 49篇 |
2000年 | 62篇 |
1999年 | 51篇 |
1998年 | 45篇 |
1997年 | 39篇 |
1996年 | 50篇 |
1995年 | 43篇 |
1994年 | 37篇 |
1993年 | 36篇 |
1992年 | 30篇 |
1991年 | 32篇 |
1990年 | 44篇 |
1989年 | 26篇 |
1988年 | 27篇 |
1987年 | 28篇 |
1986年 | 28篇 |
1985年 | 28篇 |
1984年 | 24篇 |
1983年 | 24篇 |
1982年 | 23篇 |
1981年 | 19篇 |
1980年 | 17篇 |
1979年 | 24篇 |
1978年 | 20篇 |
1977年 | 22篇 |
1976年 | 14篇 |
1975年 | 9篇 |
1974年 | 12篇 |
1973年 | 12篇 |
1969年 | 8篇 |
排序方式: 共有4656条查询结果,搜索用时 0 毫秒
71.
Prediction of maximal oxygen uptake in sedentary males from a perceptually regulated, sub-maximal graded exercise test 总被引:2,自引:0,他引:2
The purpose of this study was to assess the validity of predicting the maximal oxygen uptake (VO2(max)) of sedentary men from sub-maximal VO2 values obtained during a perceptually regulated exercise test. Thirteen healthy, sedentary males aged 29-52 years completed five graded exercise tests on a cycle ergometer. The first and fifth test involved a graded exercise test to determine VO2(max). The two maximal graded exercise tests were separated by three sub-maximal graded exercise tests, perceptually regulated at 3-min RPE intensities of 9, 11, 13, 15, and 17 on the Borg ratings of perceived exertion (RPE) scale, in that order. After confirmation that individual linear regression models provided the most appropriate fit to the data, the regression lines for the perceptual ranges 9-17, 9-15, and 11-17 were extrapolated to RPE 20 to predict VO2(max). There were no significant differences between VO2(max) values from the graded exercise tests (mean 43.9 ml x kg(-1) x min(-1), s = 6.3) and predicted VO2(max) values for the perceptual ranges 9-17 (40.7 ml x kg(-1) x min(-1), s = 2.2) and RPE 11-17 (42.5 ml x kg(-1) x min(-1), s = 2.3) across the three trials. The predicted VO2(max) from the perceptual range 9-15 was significantly lower (P < 0.05) (37.7 ml x kg(-1) x min(-1), s = 2.3). The intra-class correlation coefficients between actual and predicted VO2(max) for RPE 9-17 and RPE 11-17 across trials ranged from 0.80 to 0.87. Limits of agreement analysis on actual and predicted VO2 values (bias +/- 1.96 x S(diff)) were 3.4 ml x kg(-1) x min(-1) (+/- 10.7), 2.4 ml x kg(-1) x min(-1) (+/- 9.9), and 3.7 ml x kg(-1) x min(-1) (+/- 12.8) (trials 1, 2, and 3, respectively) of RPE range 9-17. Results suggest that a sub-maximal, perceptually guided graded exercise test provides acceptable estimates of VO2(max) in young to middle-aged sedentary males. 相似文献
72.
James CR Sizer PS Starch DW Lockhart TE Slauterbeck J 《Research quarterly for exercise and sport》2004,75(1):31-38
Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz). Differences (p < . 05) were observed between groups for knee flexion at contact and GRF at maximum knee flexion. Women averaged 5.8 degrees less flexion at contact and 1.0 N. (kg x m x s(-1))(-1) greater GRF at maximum flexion. Knee range of motion and peak GRF variables were not significantly different, but women had greater values. Women exhibited technique characteristics believed to increase ACL injury risk, but men exhibiting similar characteristics were also observed and could also be at risk. 相似文献
73.
The primary purpose of this exploratory field study was to examine the use of cognitive behavioural strategies by highly skilled orienteers prior to and during competition. A secondary purpose of the study was to investigate whether differences in the level of qualification in orienteering is related to state anxiety. The subjects were divided into three classes with respect to their international and national records. The first two classes (A and B) were composed of international and national level athletes. The third class (C) included orienteers with unknown international records. Examination of the use of behavioural cognitive strategies during competition indicated that all orienteers reported a moderate use of mental imagery, above moderate use of inner talk and a focus of attention on present action rather than past or future. The other major findings were that prior to competition, superior orienteers reported use of higher self‐efficacy, more positive outcome expectations and more task demand orientation than their less successful counterparts. Top orienteers coped more successfully with pre‐competition anxiety by lowering their anxiety to a more moderate level prior to the actual performance. 相似文献
74.
Roger M. Bartlett 《Journal of sports sciences》2013,31(9):733-752
Abstract Research into the science and medicine underlying cricket performance and injury has progressed since the First World Congress of Science and Medicine in Cricket in 1999. This review covers material on the physiological and psychological demands of the game and preparation for it, the biomechanics and motor control of cricket skills, the psychology of team dynamics, performance analysis and cricket injuries. Technological aspects of cricket equipment are also covered, where such research could influence injury risk or player performance. Fielding remains the least studied of the skills. Much more research needs to be done before we can gain a full understanding of the scientific aspects of the game. There is a need to address common definitions of injury, along with more research into injury mechanisms. Research on batting needs to bring together motor control and biomechanics more fully. The fitness demands of the game are still poorly understood, along with the mechanisms causing fatigue. Evaluation of the efficacy of intervention strategies needs to continue and to develop. The applications of research need to be communicated more to coaches and players — for example, in team dynamics — so that they can be applied, and tested further, in international matches. 相似文献
75.
Henrik S⊘rensen Morten Zacho Erik B. Simonsen Poul Dyhre‐Poulsen Klaus Klausen 《Journal of sports sciences》2013,31(6):483-495
Fast unloaded movements (i.e. striking, throwing and kicking) are typically performed in a proximo‐distal sequence, where initially high proximal segments accelerate while distal segments lag behind, after which proximal segments decelerate while distal segments accelerate. The aims of this study were to examine whether proximal segment deceleration is performed actively by antagonist muscles or is a passive consequence of distal segment movement, and whether distal segment acceleration is enhanced by proximal segment deceleration. Seventeen skilled taekwon‐do practitioners were filmed using a high‐speed camera while performing a high front kick. During kicking, EMG recordings were obtained from five major lower extremity muscles. Based on the kinematic data, inverse dynamics computations were performed yielding muscle moments and motion‐dependent moments. The results indicated that thigh deceleration was caused by motion‐dependent moments arising from lower leg motion and not by active deceleration. This was supported by the EMG recordings. Lower leg acceleration was caused partly by a knee extensor muscle moment and partly by a motion‐dependent moment arising from thigh angular velocity. Thus, lower leg acceleration was not enhanced by thigh deceleration. On the contrary, thigh deceleration, although not desirable, is unavoidable because of lower leg acceleration. 相似文献
76.
Parent Resource Centers: An Innovative Mechanism for Parental Involvement in School Choice Decisions
Hesborn Wao Vanessa L. Hein Roger Villamar Susan Chanderbhan-Forde Reginald S. Lee 《Journal of School Choice》2017,11(3):334-356
This qualitative investigation reports on the use of Parent Resource Centers (PRCs) as a mechanism for parental involvement in public school choice decisions. Interviews with parents and staff at seven PRCs in Florida revealed that PRCs employ multiple strategies to communicate choice information to parents: community-, school- and media-based outreach; outreach to hard-to-reach parents; and collaboration with other agencies. Personalized assistance and provision of choice materials are also highlighted as useful strategies. Results indicate that there is low level of awareness about school choice options among parents and thus clear and consistent communication of choice information is needed. While PRCs hold promise for increasing parental engagement in school choice, structural and systemic barriers to exercising choice decisions such as transportation and collaboration between schools and PRCs should be addressed. Methodologically, this study illustrates the power of triangulating data from parents and PRCs to illuminate our understanding of how parents make choice decisions. 相似文献
77.
78.
Boaz Shulruf Roger Booth Heather Baker Warwick Bagg Mark Barrow 《Journal of Further & Higher Education》2017,41(3):425-434
Decisions about progress through an academic programme are made by Boards of Examiners, on the basis of students’ course assessments. For most students such pass/fail grading decisions are straightforward. However, for those students whose results are borderline (either at a pass/fail boundary or boundaries between grades) the exercise of some discretion by university staff is required. In the interests of the transparency of the exercise of this discretion and to increase the chances that the ‘right’ decision is made, we tested the validity of the second version of the Objective Borderline Method (OBM2) decision-making tool in a medical programme. Our results suggest that application of OBM2 provides valid data to help university staff make robust decisions about a student’s progression through a programme, and with which to defend these decisions if that should be required. 相似文献
79.
80.
Made in America: Immigrant Students in Our Public Schools. Laurie Olsen, New York: The New Press, 1997, 276 pages, $25.00 (hardcover), ISBN 1–5658–4400–9, and $14.95 (softcover), ISBN 1–5658–4471–8. The Power of Their Ideas: Lessons for America From a Small School in Harlem. Deborah Meier, Boston: Beacon Press, 1995, 190 pages, $12.00 (softcover). ISBN 0–8070–3111–9. Yesterday, Today & Tomorrow: Meeting the Challenge of Our Multicultural America & Beyond. Paul D. Christiansen and Michelle Young, San Francisco: Gaddo Gap Press, 1996, 376 pages, $29.95 (softcover). ISBN 1–8801–9218–7. 相似文献