孔令辉正手近台反冲前冲弧圈球技术的运动学分析     

柳天杨  王新  王家正 《体育学刊》2003,10(2):106-108

运用三维摄影与影片解析技术，对孔令辉正手近台反冲前冲弧圈球技术进行了定量分析与研究，第一次较完整地阐述了横拍反胶快攻结合弧圈选手正手近台反冲前冲弧圈球技术的特点与规律，结果显示，该项技术具有动作幅度较小，瞬间发力集中，回球速度快等特点。  相似文献   

传统体育对绝经女性骨密度的影响   总被引：25，自引：1，他引：24  

周勇 《北京体育大学学报》2004,27(3):354-355

为了探讨传统体育锻炼对绝经女性骨密度的影响.将60名绝经女性,随机分为非体育锻炼组和跳绳、木兰拳、太极拳套路及太极推手等4个运动组,经10个月的实验.结果表明,非锻炼组骨量丢失,骨密度下降,4个运动组的骨密度均增加,并且太极推手组所测各指标及跳绳组桡、尺骨骨密度增加得更明显;经组间比较,太极推手组优于跳绳组(P<0.05),跳绳组优于木兰拳或太极拳套路组(P<0.05).结论:传统体育跳绳、木兰拳及太极拳运动对绝经女性骨密度的影响是积极的,是绝经女性抵抗骨量丢失,促进骨密度增大的有效运动,并且太极推手对骨量增加更全面,增大骨密度更有效.  相似文献   

排球正面上手发球技术教法研究   总被引：3，自引：0，他引：3  

许明荣  姚小玲 《体育科技》2001,22(1):15-17

在对排球正面上手发球技术教学难点及其成因分析的基础上,对课次与阶段划分、教学顺序、教学时数与练习次数、练习手段作了全面的分析,为完善和丰富正面上手发球技术教学的理论与方法提供了一定的参考依据.  相似文献   

体育产业化驱动力:一个规范解释   总被引：9，自引：3，他引：6  

程林林 《成都体育学院学报》2004,30(1):22-25

处于二元经济结构和转轨经济的背景下,城市化是体育产业化的载体.增加休闲时间、提高体育产业长期增长率、改变传统文化习俗或鼓励资本的横向进入等所导致的直接结果是改善资源在体育产业化进程中的配置效率,从而形成体育产业化的驱动力.  相似文献   

Searching for momentum in NBA triplets of free throws     

Elia Morgulev  Ofer H. Azar  Michael Bar-Eli 《Journal of sports sciences》2020,38(4):390-398

ABSTRACT

The literature on momentum is still undecided, with mixed results whether momentum exists or is only perceived to exist (“hot hand fallacy”). We explore whether momentum exists by looking at cases in which a basketball player has three consecutive free throws. A free throw is a well-defined task executed in a stable environment, allegedly giving momentum optimal chances to occur. Taking 14 NBA seasons we collected over 4500 three-free-throw sets (triplets). We obtained the outcomes of the shots as well as some additional variables about the player and the game: the player’s average free-throw percentage, home or away, and the game score and the quarter when the free throws were attempted. We first analyse the hit rates in the three shots and then proceed to regression analysis that also controls for the abovementioned variables. We address several concerns raised in the literature. All comparisons and analyses yield the same conclusion that there is no evidence for momentum in the data.  相似文献   

Self-reported symptoms and risk factors for digital ischaemia among international world-class beach volleyball players     

Daan Van De Pol  Sena Alaeikhanehshir  Mario Maas  P. Paul F.M. Kuijer 《Journal of sports sciences》2016,34(12):1141-1147

The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30–15.07) and sex (female) (OR 4.62, 90% CI 1.15–18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.  相似文献   

利用相干经典场操控激子间的纠缠度和混合度     

向少华  郑青云 《怀化学院学报》2007,26(2):41-44

借助于共生纠缠度和线性熵,研究了两个受驱动的量子点与单模腔场系统中激子纠缠度和混合度的演化动力学行为.结果表明:当无外加驱动场,激子的纠缠度和混合度呈现周期性的振荡.当激子受外经典场驱动时,其纠缠度和混合度都将减少.但Ω/g调节合适,我们能有效的抑制态的混合度而制备出一个纯净的激子纠缠态.  相似文献   

东汉草书艺术的演变及其精神内质   总被引：1，自引：0，他引：1  

徐华 《华侨大学学报(哲学社会科学版)》2002,(4):109-116

西汉末至东汉中后期，草书体确立，并由为交流而书写的实用工具升华为一种以审美为最高目标的艺术。这一由实用到审美的演变，不仅标志着中国艺术的观念由非自觉到自觉的飞跃，而且蕴涵了东汉士人精神世界中个体生命意识的自觉和艺术精神的萌生。这一变化，与东汉时期社会思潮的兴替变迁密切相关。  相似文献   

影响德国大学创新力的制度与观念解析   总被引：1，自引：0，他引：1  

张银霞  谷贤林 《比较教育研究》2011,(1):26-30

在世界范围内,德国高等教育向人们展示的不仅是其创新的显力,还有其绵延不绝的创新潜力。本文从制度与观念等维度对影响德国大学创新力的因素进行了探讨,对支撑德国大学创新力的独特理念和推动德国大学创新力的动力网络与制度保障进行了较为全面的分析。  相似文献   

张掖市土地利用/覆盖变化人口驱动力分析     

许新莉 《怀化学院学报》2007,26(8):126-128

人口作为土地利用/覆盖变化中一个活跃的因素，人口数量的多少直接影响到土地利用/覆盖变化.现以位于黑河流域中上游的张掖市为例，对该市土地利用/覆盖变化进行了分析，结果表明：人口因素对现代土地利用/覆盖变化有直接的驱动作用.  相似文献