我国优秀女子铁饼选手“人-饼”速度指标的运动学分析

摘 要：采用文献资料法、专家访谈法、三维高速影像解析法和数理统计法,对现阶段我国优秀女子铁饼运动员旋转技术的速度特征进行分析,得出以下结论：重心和铁饼的分速度大小及比例对运动员技术风格的形成有重要影响;“人-饼”系统在腾空和过渡阶段是最复杂和最难控制的,这两个阶段的系统变化对形成最佳技术具有决定性作用;我国运动员第二和第三旋转轴的速度传递稳定,第二轴髋关节和膝关节速度决定着位移的方式,第三轴肩关节速度同铁饼的时空特征有较大相关性。     

高速车削切削方程式研究

本文根据实验观察,对高速切削条件下连续型带状锯齿形切屑的形成过程进行了分析研究.研究结果表明,在锯齿形切屑的形成过程中,变形材料经历了塑性剪切变形和集中剪切滑移两个变形过程.本文作者分析了锯齿形切屑周期性形成的变形机理,对锯齿形切屑形成的有关变形参数进行了设计计算.     

Exploring mechanisms of rapid automatized naming to arithmetic skills in Chinese primary schoolers

Rapid automatized naming (RAN) is associated with children's arithmetic performance, which is multifactorial by nature and consists of arithmetic fluency, arithmetic procedure, and word problems. Yet, it is unclear whether RAN can predict all key aspects of arithmetic skills independently and what cognitive mechanisms may explain this relation. Using a sample of Chinese primary school students (N = 170), results showed that while RAN was associated with all key aspects of arithmetic skills, the relations of RAN–arithmetic procedure and RAN–word problems may be dependent on that of RAN–arithmetic fluency. Supporting the processing speed hypothesis, results further suggested that processing speed may underlie the relation between RAN and arithmetic performance. Findings made unique contribution to understanding the effect of RAN on arithmetic performance and cognitive mechanisms that may underpin this association in the context of Chinese culture.     

Power training in elite young soccer players: Effects of using loads above or below the optimum power zone

ABSTRACT

This study aimed to examine the effects of two jump squat (JS) training programs involving different loading ranges in under-20 soccer players during a preseason period. Twenty-three elite young soccer players performed sprint speed (at 5-, 10-, and 20-m), change-of-direction (COD) speed, JS peak-power (PP), and countermovement jump (CMJ) tests pre and post four weeks of training. Athletes were pair-matched in two groups according to their optimum power loads (OPL) as follows: lower than OPL (LOPL; athletes who trained at a load 20% lower than the OPL) and higher than OPL (HOPL; athletes who trained at a load 20% higher than the OPL). Magnitude-based inferences were used to compare pre- and post-training measures. Meaningful increases in the PP JS were observed for both groups. Likely and possible improvements were observed in the 5- and 10-m sprint velocity in the LOPL group. Meanwhile, possible and likely improvements were observed in the CMJ, 5- and 10-m sprint velocity, and COD speed in the HOPL group. Overall, both training schemes induced positive changes in athletic performance. Soccer coaches and sport scientists can implement the JS OPL-based training schemes presented here, either separately or combined, to improve the physical performance of youth soccer players.     

速滑运动员体能评价的研究

建立速滑运动员体能评价指标体系,对运动员在不同阶段的体能训练监控与训练效果的评定具有重要的理论与现实意义。从速滑运动训练的实践出发,结合相关文献资料确定评价速滑运动员体能指标的范围,采用特尔斐法筛选出速滑运动员体能评价的指标,运用层次分析法、百分位数法确立各个指标的权重及评价等级,将单项评价和等级评价有机结合起来,建立速滑运动员专项体能评价体系,为速滑运动员进行竞技能力实际状态的检查和诊断提供参考。     

短道速滑运动员少儿阶段训练的几点认识

短道速滑是我国参加冬奥会的主要夺金项目,探索少年儿童短道运动员的训练与成长规律具有战略意义。采用文献资料法、专家访谈法、实践经验法对少儿短道速滑运动员训练中的训练内容、方法等进行分析和探讨。认为少儿短道速滑运动员的选拔应从5～6岁开始,以培养兴趣作为训练的基本切入点,以技术为重点,采用战术与心理相结合的方法进行训练。     

我国速滑运动员科学选材现状分析

为了使我国速滑运动员选材阶段的划分更加合理、指标更加科学、评价方法更加规范,采用对近年来我国速滑运动员科学选材文献资料进行收集、分析、整理和各地速滑运动员选材情况进行调查的方法,发现我国速滑运动员科学选材工作现状处于缺乏科学系统性的停滞状态,速滑选材仍以经验选材为主;提出速滑运动员的选材应以生物年龄划分为4个阶段,且应在充分考虑遗传因素的前提下,对各阶段进行不同的身体形态、身体机能、身体素质、心理因素和专项成绩等方面的测试,并参考教练员对运动员的评价;建议尽快完善我国速滑运动员科学选材机构,提高基层教练员科学选材的基本知识和技能。     

速度滑冰竞赛学理论框架的构建

阐述了速度滑冰竞赛学的主要研究价值和意义,认为速度滑冰竞赛规则、规程和裁判法,速度滑冰竞赛裁判工作和裁判员,是速度滑冰竞赛学主要的研究内容,并从速度滑冰运动员对竞赛环境的适应和利用,速度滑冰竞赛场地和裁判器材现代化等几个方面探索速度滑冰竞赛活动的本质特征、基本规律,以及科学、合理和高效地组织速度滑冰运动竞赛的方法,提出运动员在速度滑冰竞赛中取得优异成绩的途径、方法和技巧,为有效地进行速度滑冰竞赛实践活动提供科学的理论依据。     

我国短道速滑发展现状及对策——第11届全国冬运会短道比赛调研报告

采用现场观察、文献资料等方法,对中华人民共和国第11届冬季运动会短道速滑比赛奖牌分布、对抗格局、比赛成绩等进行分析,试图通过对我国短道速滑发展现状的分析,发现制约我国短道速滑发展的主要因素。结果显示：老将实力突出,小将表现可喜,“北冰南展”发展战略的实施已见成效。认为场地条件急待解决,教练员水平有待提高,梯队建设有待完备,科研力度不足和技战术落后等是制约我国短道速滑发展的主要因素,从训练体制、教练员队伍建设、科学化训练、运动技术改进、后备人才培养和扩大项目影响等多方面提出了进一步发展短道速滑项目的对策。     

北京奥运会女子体操竞争格局与团体实力研究

通过对近年世界体操大赛体操强国的运动队及优秀运动员的录像分析、资料归纳,运用数理统计、文献资料、理论分析等方法,对当今女子体操竞争格局与实力进行分析,及对比研究,旨在为我国女子体操提供理论借鉴与战略对策。