关于Kelly问题的一个注记

利用欧氏空间向量内积的性质，对于文[1]中Kelly问题的Wolliam Kruskal猜想证明了m(d，d r)≥√d 3r，并给出了m(2，5)与m(2，6)的最小值．     

Perceptual training effects on anticipation of direct and deceptive 7-m throws in handball

We examined the effectiveness of perceptual training on the performance of handball goalkeepers when anticipating the direction of both direct and deceptive 7-m throws. Skilled goalkeepers were assigned equally to three matched-ability groups based on their pre-test performance: a perceptual training group (n = 14) received video-based perceptual training, a placebo training group (n = 14) received video-based regular training and a control group received no training. Participants in the perceptual training group significantly improved their performance compared to both placebo and control groups; however, anticipation of deceptive throws improved less than for direct throws. The results confirm that although anticipating deception in handball is a challenging task for goalkeepers, task-specific perceptual training can minimise its effect and improve performance.     

Physiological profile of a professional boxer preparing for Title Bout: A case study

This study aimed to (1) profile a professional boxer (23 years and 80 kg) with boxing-specific, muscle function, aerobic capacity and body composition tests, and (2) quantify how these measures varied during an 8-week preparation phase leading to, and post a state-Title Bout fought in the 76.2-kg class. A series of boxing-specific and muscle function tests were completed on 11 occasions: 9 prior and twice after the bout, each separated by approximately 2 weeks. The boxing test included 36 maximal punches (9 of each: lead and rear straights, lead and rear hooks) to a punching integrator measuring forces and velocity. Muscle function tests included countermovement jump, drop-jumps, isometric mid-thigh pull and isometric bench-press. Body composition was assessed using skin-fold measurements on three occasions and one dual energy X-ray absorptiometry scan. Aerobic capacity was assessed using 2 VO₂ max tests. Leading up to the bout, performance decreased in isometric mid-thigh pull (8%), isometric bench-press (5%), countermovement jump (15%) and impact forces in 3 of 4 punches (4%–7%). Whereas measures of dynamic and isometric muscle function remained depressed or unchanged post competition, punching forces (6%–15%) and aerobic power (6%) increased. Data suggest the athlete may have super-compensated following rest as fatigue dissipated and further adaptation occurred.     

应当重视师范生的信息素养和能力培养

21世纪即将来临，师范计算机教育关系到下一代教师的整体素质，是当前教育改革的重要课题。本文从分析信息时代的教师应该具备的信息养素和信息技术能力出发，剖析了当前师范计算机教育中存在的一些问题，提出了改革的思路和建议。     

现代竞技体育体能训练对改善女大学生脊柱功能的研究

脊柱功能是衡量人体健康水平的重要指标,对人体保持高质量的学习、生活和工作状态产生直接的影响。如何运用有效的训练改善和提高人体脊柱功能,应引起高度的重视。以黑龙江省30名女大学生为研究对象,制定有针对性的训练方案,进行为期3个月的运动干预实验,分5个阶段进行训练监控及训练效果评估。结果显示：全体受试对象脊柱直背趋势最为显著,脊柱姿势、柔韧性、稳定性整体较差,脊柱疾病风险较高;通过动态拉伸、颈肩及腰等功能性训练对改善女大学生脊柱功能效果显著;实施训练方案后,在第30天改善效果最为明显。     

中外女排比赛接拦回球效果及失误原因的比较分析

中外女排比赛中接拦回球数量仍然较多,占扣球总数的14%左右,比赛中80%左右的拦回球落在3m线前区域。中国女排接拦回球的效果好于日本女排、塞尔维亚女排和多米尼加女排,但与巴西女排、美国女排相比差距较大,同俄罗斯女排、意大利女排接拦回球的效果相差不大。接拦回球失误的主要原因有接拦回球队员反应跟不上造成无防守动作形成失误,其次是接拦回球队员防守意识不强未及时进入防守位置形成失误。中国女排应加强接拦回球跟进保护意识培养,努力提高各种倒地和单手垫球技术,从而提高接拦回球能力。     

女排运动员肩关节损伤原因及其康复训练策略案例研究

肩伤是专业排球运动员常见的伤病之一,而主攻的肩伤在排球运动的损伤中是最多的。以江苏女排主攻手许若亚为对象,对其在2014年9月17日—2014年10月10日期间,肩关节损伤后的系统性康复训练要素与效果进行研究,总结经验,探索肩关节损伤的有效防治方法,为提高女子排球科医保障水平,指导科学训练提供参考和指导。     

第17届排球世锦赛中外女排进攻效果对比研究

运用录像观察、数理统计和对比分析等方法,对中外女排在第17届世锦赛中扣球技战术运用情况进行研究。结果表明：中国女排是以两边拉开进攻为主并结合高度与速度等快变战术为一体的技战术打法;进攻战术的总体运用效果十分理想,与其他各国相比扣死率较高且失误率低;后排攻在比赛中展现出了强大的实力,但在强攻和快攻方面与巴西、美国等欧美强队相比还存在一定差距。建议中国女排应进一步加强对强攻能力的训练,尤其要努力丰富年轻队员的大赛阅历以保证其技术发挥的稳定性;在面对欧美强队时应努力提高一传到位率,并加强进攻队员之间的掩护配合,使各种快变战术能够在比赛中得到有效发挥,并尽量避免自身进攻方式及手段的单一化。     

Una Antorcha de Esperanza: Mexico and the 1955 Pan-American Games

Abstract

While most equate Mexican Olympism with the 1968 Olympic Games, few know the drama of the event that laid its groundwork. From the creation of the Ministry of Public Education in 1921, cultural and military leaders heavily invested in sports infrastructure to help regenerate its rural masses, but by the 1940s, post-war modernizers sought the hosting of large international athletic events to boost its prestige, foment national pride, and prove to the world it was ready to springboard into modernity. This paper recounts the triumphs, betrayals, corruption, and politics of Pan-American sport and the Olympic movement in Mexico in the 1940s and 1950s that culminated in the improbable success of the 1955 Mexico City Pan-American Games.     

小学教育专业双语师资培养实践

小学双语教学的实验已成为当前基础教育改革的一个亮点,越来越多的学校和教师青睐双语教学,实践双语教学。双语教学研究也成为我国基础教育研究的一个热点。师资问题一直是双语教学实施的一个关键问题。专家认为双语师资的培养已成为能否继续搞好双语教学的关键。本文将对南京晓庄学院小学教育专业双语师资培养实践进行探讨,并对小学双语师资的培养目标、课程设置、培养实践加以阐释。