影响三级跳远成绩的若干因素

通过阅读、整理国内外有关三级跳远方面的献资料，阐明三级跳远中助跑速度、起跳技术、三跳比例、力量以及平衡对三级跳远成绩的影响，为三级跳远的研究提供参考。     

中、外优秀艺术体操运动员跳跃类身体难度动作的比较研究

对中、外优秀艺术体操运动员跳跃类身体难度动作的比较研究结果显示:我国运动员在跳跃类身体难度动作使用的数据上与国外选手没有明显差异,但是在所选择的跳跃类身体难度动作的类型、动作的连接顺序和方式等方面却存在较大差距。同时,由于转体类和平衡类难度动作技术发展相对滞后,形成了我国运动员跳跃类难度动作选择和使用的依赖性,也暴露出我国艺术体操对难度动作的类型的选择、表现形式和连接方式等方面缺乏多样性和变化运用的弊端。     

艺术体操新兴动作—空中转体跳步难度动作的研究

笔者通过查阅大量文献资料后对转体跳步难度动作分类,并应用力学分析方法对典型动作进行技术原理分析。采用录像观察与统计,比较中外转体跳步难度动作的差异,分析国内存在的问题和原因。结论是:转体跳步难度动作是跳步动作发展的重要趋势之一;我国转体跳步难度动作完成的成功率普遍偏低,主要存在转体不到位和空中造型控制能力差两个问题;教练员对新规则掌握不够深刻,训练中对动作的要求规格不高。     

对当今世界优秀男子三级跳远运动员三跳比例的分析

通过对当今世界优秀男子三级跳远运动员的三跳比例的分析,发现当今世界大多数优秀男子三级跳远运动员采用了速度型技术,速度型技术代表了当今世界三级跳远技术发展的趋势.     

Skating

Technical evaluation in the sport of figure skating is characterized by a subjective marking system. Figure skating judges are responsible for quickly and accurately discerning the quality of technical elements as well as assigning a score to the overall aesthetic appearance of a performance. Traditionally, overall placement marks are assigned for the entire performance; however, the landing of a jump is widely acknowledged as one of the most critical elements of a skater's program. Therefore, our aims were to identify the biomechanical variables that contribute to technical success in executing landings and to establish whether landings rated as biomechanically optimal are also awarded high technical merit scores by judges. Ten nationally ranked competitive figure skaters were asked to execute on‐ice, double and triple revolution jumps and to try to land the jumps void of technical faults within a calibrated space. Data were collected at 60 Hz using standard three‐dimensional videography. Data reduction was done using the APAS system (Ariel Dynamics Inc). Concurrently, videotapes were viewed and evaluated by 42 accredited judges to determine the perceived technical quality of the landing performances. Judges were asked to evaluate the landing phase of each jump against a landing criteria document. A comparative criteria model was developed to facilitate an assessment of excellence in landing performances through both empirical and subjective analyses. Results of these analyses were twofold: a biomechanical profile of on‐ice landings was obtained, and on‐ice jump landing strategies rated by empirical evaluations were in agreement with judge's perceptions of the same performances.     

Peripheral alterations after two different concentric power protocols

Abstract

The aims of the present study were to assess the ability of explosive concentric contractions to induce high-frequency fatigue, and to determine what effects the number of repetitions and number of sets have upon peripheral fatigue. Nine male students performed two protocols (6 sets, 5 min and 1 week rest between sets and protocols, respectively) with a different number of concentric jumps in a set on the sledge (10 vs. 20 jumps in the first (S10) and the second protocol (S20), respectively). Isometric twitch torque, torque during low-frequency (20 Hz) and high-frequency (100 Hz) electrical stimulation of the vastus lateralis were measured (before protocols and 30 s after sets). Peak twitch torque increased, while contraction and half-relaxation times shortened during the S10 protocol (P<0.05). The increase in peak twitch torque was accompanied by non-significant reductions in contraction time and half-relaxation time in the S20 protocol. High- and low-frequency torques did not change significantly in either protocol. The high- to low-frequency torque ratio increased significantly (P<0.05) after the fourth set in the S10 protocol. Post-activation potentiation was the main reason for enhanced contractile response after both protocols. There were no alterations in high-frequency torque or reductions in the high- to low-frequency torque ratio, even with increased sets and repetitions. Explosive concentric contractions showed no potential to induce high-frequency fatigue, when separated with long periods of rest.     

如何提高初学者跳远助跑的准确性

对如何提高跳远助跑的准确性进行分析研究，证明提高跳远助跑准确性的练习方法，分析解决了提高跳远助跑准确性的几个问题，特别是在跳远运动实践中，速度训练效果如何转化为提高跳远助跑准确性进行了详细的理论分析，认识到跳远教学和训练中如何提高助跑的准确性。     

带Poisson跳随机微分方程解的存在与唯一性

讨论了一类带Poisson跳的随机微分方程解的存在唯一性问题,在局部Lipschitz条件下给出了带跳随机微分方程解的存在与唯一性的充分条件.     

外汇汇率买入的带跳扩散股票的期权定价

通过建立股票价格服从带跳扩散过程的随机微分方程和外币汇率的随机微分方程,研究与之相关联的欧式期权定价问题,并通过鞅定价方法推导出买入欧式期权的定价公式。     

武术跳跃动作落地稳定性探讨

针对学生在武术套路演练中容易出现跳跃动作落地不稳，造成附加支撑或摔倒等问题，结合从事武术专业教学的经验，进行调查、分析，从技术、心理和体能方面探讨造成学生跳跃动作落地不稳定的原因。