对掷铁饼旋转技术的生物力学研究   总被引：4，自引：0，他引：4  

张健  冯晓东 《首都体育学院学报》1999,(3)

运用影片解析的方法和运动生物力学理论, 针对掷铁饼旋转技术的特征进行分析, 为进一步研究掷铁饼技术提供了理论依据, 有助于教练和运动员正确认识掷铁饼技术  相似文献   

论“加速度”式英语教学模式的理论与实践     

胡国洪 《教育与教学研究》2011,(12):84-85,89

在加速度存在的情况下,速度随着时间增加而加快。而在中国目前的英语教学中,每一个阶段和每一类语言知识讲授几乎都是采用同样的节奏和方式逐一进行,忽视了"加速度"的存在。针对英语课堂教学中的这些问题,构建一种全新"加速度"式的英语教学模式。在理论上,要明确"加速度"英语的本质和应用范围,要统一和明确教学目的,要建立"学而思,思而用"的教学方式,创造性地教与学。在教学实践中,典型例子法、数学模型法、逆向思维法、英汉对照法在一定程度上能促进学生创造性思维能力的发展。  相似文献   

The influence of the hand’s acceleration and the relative contribution of drag and lift forces in front crawl swimming     

Vassilios Gourgoulis  Alexia Boli  Nikolaos Aggeloussis  Panagiotis Antoniou  Argyris Toubekis  Georgios Mavromatis 《Journal of sports sciences》2015,33(7):696-712

The aim of this study was to assess the effect of the hand’s acceleration on the propulsive forces and the relative contribution of the drag and lift on their resultant force in the separate phases of the front crawl underwater arm stroke. Ten female swimmers swam one trial of all-out 25-m front crawl. The underwater motion of each swimmer’s right hand was recorded using four camcorders and four periscope systems. Anatomical landmarks were digitised, and the propulsive forces generated by the swimmer’s hand were estimated from the kinematic data in conjunction with hydrodynamic coefficients. When the hand’s acceleration was taken into account, the magnitude of the propulsive forces was greater, with the exception of the mean drag force during the final part of the underwater arm stroke. The mean drag force was greater than the mean lift force in the middle part, while the mean lift force was greater than the mean drag force in the final part of the underwater arm stroke. Thus, swimmers should accelerate their hands from the beginning of their backward motion, press the water with large pitch angles during the middle part and sweep with small pitch angles during the final part of their underwater arm stroke.  相似文献   

三轴加速度传感器系统在运动技术分析领域的研究与应用     

朱明 《冰雪运动》2015,(2):89-96

为满足在运动训练过程中的人体三维空间技术特征研究的需要,开发一套三轴向加速度传感器系统.该系统由下位机和上位机两部分组成,其中下位机部分由加速度传感器、传感器拾取单元、数据处理单元、电源监测与保护单元和无线传输单元组成,上位机部分由数据采集和分析软件组成.该系统具有四通道同步采集功能,结合同步视频,可对运动员的肢体关节、比赛训练器械等技术组成要素进行运动学和动力学参数进行实时采集与分析.以体育训练中常用的杠铃深蹲训练为实验性应用领域,对速滑和举重两种项目的杠铃深蹲训练进行技术分析,通过对三轴加速度传感器采集数据的分析,找出不同项目间杠铃深蹲动作技术的特征与差异,为今后深入开展加速度传感器系统的开发与相关应用提供研究基础.  相似文献   

Knowledge of bout duration influences pacing strategies during small-sided games     

John Andrew Sampson  Hugh Head Kelsham Fullagar  Tim Gabbett 《Journal of sports sciences》2015,33(1):85-98

This investigation examines pacing during intermittent team sports. Sixteen junior Rugby League players participated in eight different small-sided offside touch games. All games were 24 min, but bout durations differed in continuous (1 × 24 min) or repeated (2 × 12, 3 × 8, 4 × 6, 6 × 4, 8 × 3, 12 × 2 or 24 × 1 min) formats. Repeat bouts were interspersed by 2 min of passive rest, and participants were informed of the bout duration immediately prior to the game. Heart rates, ratings of perceived exertion and data gathered from global positioning system devices were used to investigate the pacing strategies employed within each game. No significant (P > 0.05) between-game differences were observed in total distance; however, during the 1-min bouts, high-speed movement was significantly (P < 0.05) increased, during the first and second quarters of the 24 × 1-min game compared to all other formats (effect size range: 0.75 ± 0.61–1.38 ± 0.47). Furthermore, the rate of decline in high-speed movement over-time was greatest during the 24 × 1-min game with large differences observed between the first and third quarters (effect size: 0.90 ± 0.58). Greater moderate-speed (effect size range: 0.62 ± 0.63–1.56 ± 0.40) and less low-speed (effect size range: 0.69 ± 0.62–1.54 ± 0.40) distances were also observed during the 1-min bouts, yet heart rates were higher during the continuous 1 × 24-min game. Pacing strategies during intermittent activities are influenced by the number and duration of exercise bouts. Practitioners should consider within-game bout durations when prescribing game-based activities to improve aerobic capacity.  相似文献   

Dealing with Challenges of Energy and Climate Change:Policy-oriented Researches     

WANG Yi 《中国科学院院刊(英文版)》2014,(4):299-300

<正>Rapid growth of total energy consumption and carbon emissions is a challenge to sustainable energy development In the first decade of the 21st century,along with the acceleration of industrialization and urbanization,especially the rapid development of heavy and chemical  相似文献   

周红发球技术特征的解析     

龚雅丽  胡进  邢红林 《西安体育学院学报》1995,(1)

通过对周红发球时身体主要关节声、（肩、肘、腕）运动轨迹解析，找出击球时鞭打动作的特征及其球速快的缘由．特征是以腰为轴，以肩、肘、腕三节鞭打的动作，使手腕获得较大的加速度、其他队员多是以肩为轴的肘、腕二节鞭打动作．  相似文献   

运动心脏心肌收缩成分缩短加速度的生理意义     

李昭波 《西安体育学院学报》1994,(3)

本文首次较全面论述了心肌收缩成分缩短加速度这一类精确地、敏感地，在更深层次上反映心肌收缩性能的指标在运动心脏功能研究中的生理意义，详细探讨了心肌收缩成分缩短加速度类指标提出的背景、测量原理，曲线波型特点及参数值．为这类指标在运动性心脏心肌收缩性能的研究中的应用，提供了基础参考资料。  相似文献   

王怡的单脚背飞扣球技术特征   总被引：3，自引：0，他引：3  

龚雅丽  刑红林  赵文娟 《西安体育学院学报》1994,(3)

本文通过摄影、测试、解析得出：单脚背飞和球的球速比正面扣球球速快的优势．３名单脚背飞扣球队员中，王怡助跑速度适宜，腾起角合理，较好地利用身体的前冲力量，使空中位移增长，有较充分时间做空中转体击球动作．从而使她转体利落、连贯、完整、协调．能运用转体的惯性．增加击球时手指掌的加速度，通过比较，王怡的单脚背飞扣球技术、动作合理完整、协调，可称为优秀的单脚背飞和球手．  相似文献   

用加速度传感器直接测量加速度的实验验证   总被引：6，自引：0，他引：6  

施宝兴 《南京体育学院学报(社会科学版)》2001,15(1):4-6

研究目的是为了探索用加速度传感器测量环节加速度可行性及其数据处理的方法。研究结果显示加速度传感器得到的加速度值具有较高的精确度，角加速度也可通过两个线加速度传感器来测量，由角加速度积分得到的角位移值与影片解析的结果相当吻合，建议运动生物力学测量中加强加速度的直接测量。  相似文献