首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1048篇
  免费   22篇
  国内免费   4篇
教育   749篇
科学研究   93篇
各国文化   10篇
体育   134篇
综合类   6篇
文化理论   8篇
信息传播   74篇
  2024年   2篇
  2023年   10篇
  2022年   18篇
  2021年   23篇
  2020年   28篇
  2019年   38篇
  2018年   59篇
  2017年   38篇
  2016年   34篇
  2015年   33篇
  2014年   32篇
  2013年   164篇
  2012年   28篇
  2011年   41篇
  2010年   34篇
  2009年   25篇
  2008年   30篇
  2007年   29篇
  2006年   28篇
  2005年   36篇
  2004年   78篇
  2003年   30篇
  2002年   45篇
  2001年   30篇
  2000年   14篇
  1999年   5篇
  1998年   11篇
  1997年   9篇
  1996年   6篇
  1995年   7篇
  1994年   15篇
  1993年   7篇
  1992年   6篇
  1991年   10篇
  1990年   9篇
  1989年   4篇
  1988年   5篇
  1987年   3篇
  1986年   6篇
  1985年   11篇
  1984年   2篇
  1983年   3篇
  1982年   2篇
  1981年   6篇
  1979年   2篇
  1974年   3篇
  1973年   4篇
  1943年   2篇
  1870年   1篇
  1847年   2篇
排序方式: 共有1074条查询结果,搜索用时 15 毫秒
991.

In this article, the authors describe the ways in which a set of policies has had what seem to be extensive and long lasting effects precisely because these policies are coherently linked to larger dynamics of social transformation and to a coherent strategy that aims to change the mechanisms of the state and the rules of participation in the formation of state policies. They describe and analyze the policies of the 'Popular Administration' in Porto Alegre, Brasil but, more specifically, they focus on the 'Citizen School' and on proposals that are explicitly designed to radically change both the municipal schools and the relationship between communities, the state, and education. This set of polices and the accompanying processes of implementation are constitutive parts of a clear and explicit project aimed at constructing not only a better school for the excluded, but also a larger project of radical and thick democracy. The reforms being built in Porto Alegre are still in formation, but the authors argue that they have crucial implications for how we might think about the politics of education policy and its role in social transformation.  相似文献   
992.
Book reviews     
The following books are reviewed.

Teaching Public Issues in the High School D. W. OLIVER & J. P. SHAVER (1966) Boston: Houghton Mifflin.

Professional Experience and the Investigative Imagination: the ART of reflective writing RICHARD WINTER, ALYSON BUCK & PAULA SOBIECHOWSKA (1999) London: Routledge. 240 pp. ISBN 0 415 19542 X (hb) £50.00, ISBN 0 415 19543 8 (pb) £ 16.99  相似文献   
993.
Europe’s objectives of economic growth and job creation require large numbers of professionals who are willing and able to innovate and rise above themselves. In this article, a concept of excellence is developed that can be broadly applied in professional higher education. This concept of excellence derives from three concepts which the German philosopher Friedrich Nietzsche developed in The Gay Science (2001/1887): self-transcendence, self-control and self-styling. By starting with Nietzsche’s radical thoughts, the author aims to grasp the probabilities and challenges of preparing all students for their professional future. Several proposals for educational practice are outlined based on this perspective of ‘excellence for all’.  相似文献   
994.
Electromyographic (EMG) activity of the leg muscles and the ground reaction forces were recorded in 17 elite male middle-distance runners, who performed isometric maximal voluntary contractions (MVC) as well as running at different speeds. Electromyograms were recorded from the gluteus maximus, vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior. The results indicated that the averaged EMG (aEMG) activities of all the muscles studied increased (P?<?0.05) with increasing running speed, especially in the pre-contact and braking phases. At higher speeds, the aEMG activities of the gastrocnemius, vastus lateralis, biceps femoris and gluteus maximus exceeded 100% MVC in these same phases. These results suggest that maximal voluntary contractions cannot be used as an indicator of the full activation potential of human skeletal muscle. Furthermore, the present results suggest that increased pre-contact EMG potentiates the functional role of stretch reflexes, which subsequently increases tendomuscular stiffness and enhances force production in the braking and/or propulsive phases in running. Furthermore, a more powerful force production in the optimal direction for increasing running speed effectively requires increased EMG activity of the two-joint muscles (biceps femoris, rectus femoris and gastrocnemius) during the entire running cycle.  相似文献   
995.
Abstract

To develop a track version of the maximal anaerobic running test, 10 sprint runners and 12 distance runners performed the test on a treadmill and on a track. The treadmill test consisted of incremental 20-s runs with a 100-s recovery between the runs. On the track, 20-s runs were replaced by 150-m runs. To determine the blood lactate versus running velocity curve, fingertip blood samples were taken for analysis of blood lactate concentration at rest and after each run. For both the treadmill and track protocols, maximal running velocity (v max), the velocities associated with blood lactate concentrations of 10 mmol · l?1 ( v 10 mM) and 5 mmol · l?1 ( v 5 mM), and the peak blood lactate concentration were determined. The results of both protocols were compared with the seasonal best 400-m runs for the sprint runners and seasonal best 1000-m time-trials for the distance runners. Maximal running velocity was significantly higher on the track (7.57 ± 0.79 m · s?1) than on the treadmill (7.13 ± 0.75 m · s?1), and sprint runners had significantly higher v max, v 10 mM, and peak blood lactate concentration than distance runners (P<0.05). The Pearson product – moment correlation coefficients between the variables for the track and treadmill protocols were 0.96 (v max), 0.82 (v 10 mM), 0.70 (v 5 mM), and 0.78 (peak blood lactate concentration) (P<0.05). In sprint runners, the velocity of the seasonal best 400-m run correlated positively with v max in the treadmill (r = 0.90, P<0.001) and track protocols (r = 0.92, P<0.001). In distance runners, a positive correlation was observed between the velocity of the 1000-m time-trial and v max in the treadmill (r = 0.70, P<0.01) and track protocols (r = 0.63, P<0.05). It is apparent that the results from the track protocol are related to, and in agreement with, the results of the treadmill protocol. In conclusion, the track version of the maximal anaerobic running test is a valid means of measuring different determinants of sprint running performance.  相似文献   
996.
Abstract

In this study, we examined the effect of rapidly increased training volume and intensity on hormonal responses (salivary cortisol [C] and urinary dehydroepiandrosterone sulphate [DHEA-S]) and recovery-stress state perceived by 12 female cyclists. Over the 4-day experimental period, there was an average increase in training load of approximately 122% compared with that during the previous 12 days. Scores on subscales of the Recovery Stress Questionnaire for Athletes increased for the somatic component of stress (Fatigue, Emotional Stress and Social Stress; P < 0.05) and decreased the factor indicating recovery (General Well Being; P < 0.05) after the heavy training period. The training programme increased resting concentrations of salivary cortisol (P < 0.05) and decreased the DHEA-S/C ratio (P < 0.05). The increase in training load of cyclists was correlated with this hormonal ratio (r = ?0.48, P < 0.05). Changes in resting cortisol concentration as a result of heavy training stress were positively related to the change in Physical Complaints (r = 0.69, P < 0.01). Negative relationships were also found between changes in the DHEA-S/C ratio and changes in the somatic component of stress. The present results suggest that there is a dose–response relationship between increased training load, resting DHEA-S/C ratio and subjective assessment of stress and recovery, implying that this ratio could be used as an indicator of training status in female athletes.  相似文献   
997.
Abstract

The purpose of the present research was to test the applicability of the Dualistic Model of Passion (Vallerand et al., 2003 Vallerand, R. J., Blanchard, C. M., Mageau, G. A., Koestner, R., Ratelle, C.Léonard, M. 2003. Les passions de l'âme: On obsessive and harmonious passion. Journal of Personality and Social Psychology, 85: 756767. [Crossref], [PubMed], [Web of Science ®] [Google Scholar]) to being a sport (football) fan. Three studies provided support for this dualistic conceptualization of passion. Study 1 showed that harmonious passion was positively associated with adaptive behaviours (e.g. celebrate the team's victory), whereas obsessive passion was positively associated with maladaptive behaviours (e.g. risking losing one's job to go to a game). Study 2 used a short Passion Scale and showed that harmonious passion was positively related to the positive affective life of fans during the 2006 FIFA World Cup, psychological health (self-esteem and life satisfaction), and public displays of adaptive behaviours (e.g. celebrate the team's victory into the streets), whereas obsessive passion was predictive of maladaptive affective life (e.g. hating opposing teams' fans) and behaviours (e.g. mocking opposing teams' fans). Finally, Study 3 examined the role of obsessive passion as a predictor of partner's conflict that in turn undermined partner's relationship satisfaction. Overall, the present results provided support for the Dualistic Model of Passion. The conceptual and applied implications of the findings are discussed.  相似文献   
998.
Abstract

The aims of this study were to test for the presence of a relative age effect among male (n = 119,715) and female (n = 12,823) members of the shooting sports federation, and to determine whether any such effect has an impact on dropout from the sport. For the boys and girls, the results show a uniform distribution of dropout. A relative age effect was not found for the girls, showing that in female shooting sports there is no such effect. For the males, a significant statistical relative age effect was not detected in the 18–20 and 13–14 year categories. However, a relative age effect was found among adults and the 11–12 and under 11 year categories. A significant “inverse” relative age effect was found for the 15–17 year group. Further qualitative research is needed to clarify which factors contribute to this asymmetric distribution of birth dates in French male shooting sports.  相似文献   
999.
Abstract

The aim of this study was to compare the lactate indices provided by single- and double-breakpoint models with lactate thresholds obtained with conventional methods. Arterial samples for the determination of lactate concentrations were drawn from eight participants at rest and every minute during a ramp test (15 W · min?1) on a cycle ergometer. Lactate thresholds were determined from a blood lactate concentration equal to 4 mM (LT4), from an increase of 1 mM above the resting level (Δ1 mM), and from indirect methods using ventilatory parameters. Other indices were computed from the modelling of the lactate curve using an exponential function (LSI), a polynomial function (Dmax), a semi-log model (SLog), a parabola plus delay model (Mod P), and a two-breakpoint model (Mod M). Mod P and Mod M showed poor agreement with the other methods. LT4, Dmax, LSI, and respiratory exchange ratio equal to 1 were correlated with each other (0.81 ≤ R ≤ 0.92) and their mean differences ranged from 2.8 to 15 W, with limits of agreement within the range ± 24.6 to ± 42.4 W. These results question the interest in breakpoints models to detect lactate thresholds, knowing that LT4, LSI, Dmax, and respiratory exchange ratio equal to 1 provide indices that occur at similar power outputs.  相似文献   
1000.
Abstract

Few studies have focused on the effect of posture during sprint start. The aim of this study was to measure the effect of the modification of horizontal distance between the blocks during sprint start on three dimensional (3D) joint angular velocity. Nine trained sprinters started using three different starting positions (bunched, medium and elongated). They were equipped with 63 passive reflective markers, and an opto-electronic Motion Analysis® system was used to collect the 3D marker trajectories. During the pushing phase on the blocks, norm of the joint angular velocity (NJAV), 3D Euler angular velocity (EAV) and pushing time on the blocks were calculated. The results demonstrated that the decrease of the block spacing induces an opposite effect on the angular velocity of joints of the lower and the upper limbs. The NJAV of the upper limbs is greater in the bunched start, whereas the NJAV of the lower limbs is smaller. The modifications of NJAV were due to a combination of the movement of the joints in the different degrees of freedom. The medium start seems to be the best compromise because it leads, in a short pushing time, to a combination of optimal joint velocities for upper and lower segments.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号