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91.
对中长距离自由泳项目的配速方案的总体特征、各项目特征,及提高配速水平的方法进行了分析,并提出了提高我国中长距离自由泳项目运动员配速水平的对策与建议,旨在对今后我国该类项目训练与配速研究提供理论参考。  相似文献   
92.
Abstract

The aim of this study was to examine the match activities of top-class female assistant referees (mean age 34.8 years, s=3.5; stature 1.64 m, s=0.05; weight 58.1 kg, s=7.4; body mass index 21.6 kg · m–2, s=2.4) in relation to the offside line. Computerized match analyses were performed on 14 top-class assistant referees during 10 matches (a total of 20 observations) from the 2006 Fédération Internationale de Football Association (FIFA) under-20 Women's World Championship held in Russia. In addition, the position of the second last defensive player of both teams was calculated throughout the matches to determine the distance from the assistant referee to the offside line. The total distance covered during a game was 5594 m (s=473), of which 27% was sideways movements (1492 m, s=135). High-intensity activities (>13 km · h–1) accounted for 1999 m (s=371). Mean distance from the offside line during the entire match was 1.06 m (s=0.26). Total distance covered, high-intensity activities, and distance from the offside line were not different (P>0.05) between the two halves of the game or consecutive 15-min match periods. Our results show that: (1) the kinematic demands placed on top-class female assistant referees are similar to those of top-class male assistant refereeing except for the amount of high-intensity activities, and (2) assistant referees were able to maintain the distance from the offside line during the match, which suggests an ability to keep up with the pace of the play throughout the match.  相似文献   
93.
运用体质测试和数理统计法,对《国民体质测定标准》(幼儿部分)中网球掷远和立定跳远的测试结果进行分析,并通过蹬力测试和拉力测试进行对比。结果表明,由于幼儿的投掷技术和跳跃技术掌握较差,测试结果误差较大,所以,网球掷远和立定跳远不能准确地评价幼儿身体素质的发展状况。  相似文献   
94.
Abstract

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   
95.
Abstract

The relationship between date of birth and success in a variety of sports, including hockey, is well established. This phenomenon is known as the relative age effect (RAE). We model the RAE in Canadian youth hockey as a positive feedback loop where an initial age advantage is reinforced through additional training and playing opportunities based on perceived skill superiority. The same causal mechanism leads to a higher quit rate for relatively younger players. Our model effectively replicates the birth month distribution of Canadian National Hockey League players (R2 = 86.79%) when driven by Canadian birth distributions. We use this model to evaluate three policies that aim to lessen the RAE. All of the policies reduce the RAE with a significant delay. The most effective policy is a combination of providing additional support to age disadvantaged children and rotating the cut-off date for youth leagues between January 1st and July 1st annually. In equilibrium, this approach leads to a 96% reduction in the RAE compared to the base case.  相似文献   
96.
运用文献资料法,总结国内外中长跑技术的研究成果及最新动态。结果表明:近年来,国内外对中长跑技术的研究缺乏突破和创新。主要表现在:研究还是从二维平面角度,探讨中长跑运动员途中跑技术的运动学特征,而对运动员途中跑技术三维空间运动学和动力学特征缺少研究。在此基础上笔者也对今后中长跑技术的研究方向给予了展望。  相似文献   
97.
含蓄是中国文学语言中的重要属性,它不仅可以拉开读者与文学作品间的距离,在赋予文学作品张力的同时,给读者驰骋想象的空间。在翻译活动中,译者在适当的审美距离之内充分发挥其主观能动性,把握好原文中的含蓄表达和蕴含情感,从而使译文读者在译文阅读过程中获得与原文读者尽可能相似的审美感受,也使译文获得与原文相似的审美效果。  相似文献   
98.
信息技术的发展赋予了网络时代学习新的特点,同时也呼唤着教育资源的开放与共享。麻省理工学院开放课件项目(简称MIT OCW)"开放与共享"理念的确立与实施,对我国远程教育课程资源建设的决策定位、资源体系、平台环境和教学科研等方面具有借鉴作用。  相似文献   
99.
This study examined the effectiveness of curriculum-focused diversity initiatives on a college campus by determining the relationships between GPA, social class, year in school, residential status, racial diversity courses taken, and cross-racial friendships on the level of social distance between Whites-Blacks, Whites-Hispanics, Hispanics-Whites, Hispanics-Blacks, Blacks-Whites, and Blacks-Hispanics. The data suggest that, while the institution does a good job of bringing diverse groups of students to the campus, it does not effectively reduce the level of social distance among many members of the different racial groups on campus. Using the Intergroup Contact Hypothesis, the article concludes by suggesting means by which social distance among racial groups on campus might be decreased.  相似文献   
100.
This study explores issues related to the tutor’s role when initiating tutoring as an institutional strategy at a conventional university. Based on a pilot tutoring program implemented in four college courses, we investigated the perceptions of instructors, tutors and students regarding the role of tutoring and whether it affected the psychological distance between the different types of participants. The results indicated that instructors’ perceptions of the tutor’s primary role and the psychological distance from the students and the tutors differed from the perceptions of the tutors and the students, perhaps because the instructors perceived tutors as a source of instructor support rather than student support. Implications and suggestions are discussed.  相似文献   
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