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   196篇
  免费   0篇
教育   122篇
科学研究   11篇
体育   32篇
文化理论   6篇
信息传播   25篇
  2019年   4篇
  2018年   13篇
  2017年   4篇
  2016年   8篇
  2015年   2篇
  2014年   6篇
  2013年   21篇
  2012年   7篇
  2011年   7篇
  2010年   7篇
  2009年   7篇
  2008年   11篇
  2007年   11篇
  2006年   6篇
  2005年   5篇
  2004年   3篇
  2002年   9篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1995年   5篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1985年   2篇
  1984年   5篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1979年   3篇
  1977年   2篇
  1973年   1篇
  1969年   1篇
  1968年   2篇
  1967年   2篇
  1966年   1篇
  1965年   1篇
  1964年   1篇
  1963年   2篇
  1959年   1篇
  1892年   3篇
  1885年   1篇
  1840年   1篇
排序方式: 共有196条查询结果,搜索用时 15 毫秒
121.
122.
The aims of the present study were (1) to analyse the physical demands of top-class referees and (2) to compare their official FIFA fitness test results with physical performance during a match. The work rate profiles of 11 international referees were assessed during 12 competitive matches at the 2003 FIFA Under-17 World Cup and then analysed using a bi-dimensional photogrammetric video analysis system based on direct lineal transformation (DLT) algorithms. In the first 15 min of matches, the referees were more active, performing more high-intensity exercise (P < 0.01) than in the first 15 min of the second half. During the second half of matches, the referees covered a shorter distance (P < 0.01), spent more time standing still (P < 0.05), and covered less ground cruising (P < 0.05), sprinting (P < 0.05), and moving backwards (P < 0.001) than in the first half. Also in the second 45 min, the distance of referees from infringements increased (P < 0.05) in the left attacking zone of the filed. There was also a decrease (P < 0.05) in performance in the period following the most high-intensity activity, compared with the mean for the 90 min. Time spent performing high-intensity activities during a match was not related to performance in the 12-min run (r(2) = 0.30; P < 0.05), the 200-m sprint (r(2) = 0.05; P < 0.05), or the 50-m sprint (r(2) = 0.001; P < 0.05). The results of this study show that: (1) top-class referees experienced fatigue at different stages of the match, and (2) the typical field tests used by FIFA (two 50-m and 200-m sprints, followed by a 12-min run) are not correlated with match activities.  相似文献   
123.
124.
A proposal is made in this paper for a broadening of perspective in evaluative bibliometrics by complementing the (standard) times cited with a cited reference analysis for a field-specific citation impact measurement. The times cited approach counts the citations of a given publication set. In contrast, we change the perspective and start by selecting all papers dealing with a specific research topic or field (the example in this study is research on Aspirin). Then we extract all cited references from the papers of this field-specific publication set and analyse which papers, scientists, and journals have been cited most often. In this study, we use the Chemical Abstracts registry number to select the publications for a specific field. However, the cited reference approach can be used with any other field classification system proposed up to now.  相似文献   
125.
In the Essential Science Indicators (Thomson Reuters), a research front exists to the h index (entitled “GOOGLE SCHOLAR H-INDEX; SCIENCE CITATION INDEX; GENERALIZED HIRSCH H-INDEX; H INDEX; GOOGLE SCHOLAR CITATIONS”) consisting of a group of highly cited papers. We used HistCite to analyze the structure and relationships of the 45 papers forming the h index research front. Since we were interested in the topics of research on the h index at the front, we classified each paper according to its main topic. Six topics (inductively generated) were sufficient to classify the 45 papers: (1) citation database, (2) empirical validation study, (3) new application, (4) theoretical analysis, (5) new index development, and (6) literature review.  相似文献   
126.
This review summarizes research conducted in our laboratories over the past 5 years aimed at determining the temporal and spatial relationships between eye and hand movements and the amount of central processing that must occur before performing a manual aiming movement, relative to the amount of processing that is done online. All of our research to date points to a two-component model of speed-accuracy control in manual aiming. Several studies have shown that eye and hand movements in manual aiming are inextricably linked both temporally and spatially. Typically, the eye arrives in the vicinity of the target first; this coincides with peak acceleration of the finger during the initial impulse phase of a movement. There is also significant temporal and spatial coupling of the finger, elbow and shoulder in aiming, and movements appear to evolve in a proximal-to-distal fashion. Movements are endpoint driven and variability is reduced with distal approximation to the target. This movement control strategy means that visual information is not only available for use in modifying responses, but there is sufficient time available for its use. In sequential complex aiming movements, the use of visual feedback and on-line processing become even more important. Practice does not diminish the need for on-line processing; rather, its use appears to ensure greater movement efficiency.  相似文献   
127.
The aim of this study was to examine the physical and perceptual-cognitive demands imposed on UEFA top-class referees and assistant referees during the final round of the Euro 2000 Championship. To investigate the physical workload, the heart rates during matches were monitored by short-range radio telemetry and translated to different workloads expressed as a percentage of maximal heart rate. For measurement of the perceptual-cognitive workload, video-recordings of games were used to obtain the average number of observable decisions taken by a referee. On average, referees and assistant referees performed the matches at 85±5% and 77±7% of their maximal heart rate, respectively. Over the 31 games, the mean number of observable decisions was 137 (range 104–162), 64% of which were based on communication with the assistant referees and/or the fourth official. To optimize the physical preparation of top-class match officials, the results of this study support the application of intensive and intermittent training sessions, which should place priority on high-intensity aerobic stimuli. In addition, video training is discussed as an additional method for improving match officials' decision making.  相似文献   
128.
Abstract

The objective of this study was to analyse the correctness of the offside judgements of the assistant referees during the final round of the FIFA 2002 World Cup. We also contrasted two hypotheses to explain the errors in judging offside. The optical error hypothesis is based on an incorrect viewing angle, while the flash-lag hypothesis refers to perceptual errors associated with the flash-lag effect (i.e. a moving object is perceived as spatially leading its real position at a discrete instant signalled by a briefly flashed stimulus). Across all 64 matches, 337 offsides were analysed using digital video technology. The error percentage was 26.2%. During the first 15 min match period, there were significantly more errors (38.5%) than during any other 15 min interval. As predicted by the flash-lag effect, we observed many more flag errors (86.6%) than non-flag errors (13.4%). Unlike the predictions of the optical error hypothesis, there was no significant difference between the correct and incorrect decisions in terms of the positioning of the assistant referees relative to the offside line (0.81 and 0.77 m ahead, respectively). To reduce the typical errors in judging offside, alternative ways need to be considered to teach assistant referees to better deal with flash-lag effects.  相似文献   
129.
130.
Mit Schreiben vom 30.11.2010 legte die zust?ndige Wissenschaftsministerin, Frau Univ.-Prof. Mag. Dr. Beatrix Karl, den Entwurf zu einem „Qualit?tssicherungsrahmengesetz 2011“ zur Begutachtung vor; das genannte Gesetz beinhaltet die Neukodifikation eines „Qualit?tssicherungsgesetzes“, weiters die Etablierung eines „Privatuniversit?ten- und Zertifikatslehrgangsgesetzes“ – welches das bisher geltende Universit?ts-Akkreditierungsgesetz ersetzen soll – sowie die Novellierung des „Fachhochschul-Studiengesetzes“.  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