太极拳教学探讨

太极拳作为高校体育教材内容,受到学生的喜爱,练好太极拳,坚持常年练习,可以使其终身受益。从教学实践中学生最难掌握是动作不够柔顺,太极拳韵味表现不够。     

从移动靶接靶技术分析飞碟双向看接配合的重要性

点明了移动靶接靶技术和飞碟双向看接靶技术之间的共性 ,旨在从对移动靶接靶技术的分析中阐述飞碟双教学训练中看接配合的关键性和重要性 ,从而提高运动员在飞碟双向训练中对关键技术的领悟与掌握运用。     

健美操的动作节奏与音乐节奏的内在效应

节奏是健美操与音乐内在联系的纽带 ,音乐的节奏严格控制着动作的节奏 ,也是增强健美操艺术感染力的主要手段 ,其内在效应主要有节奏与律动的同步效应、情感与运动的共鸣效应、风格与结构的统一效应。     

惯性及惯性力

惯性是物理学中最基本的概念之一,也是学习物理学最早遇到的概念之一。这一极为普通和平凡的概念曾经引导许多物理学家深入思考和剖析。从力和惯性的概念出发,对人们长时间关于惯性力争论的原因加以论述,对惯性系的动力学问题和非惯性系的动力学问题进行了讨论,并用相对运动论的观点阐述了自己对惯性系和非惯性系的一些看法。     

武术套路竞赛方法改革的新思路

依据运动竞赛方法学的基础理论，剖析现行武术套路竞赛方法存在的诸多弊端，提出了武术套路竞赛引入淘汰制的新思路。认为，淘汰制的引入对保持武术套路的本质属性、提高武术套路运动的竞技性及观赏性等方面具有重要作用；淘汰制可以有效解决目前武术套路竞赛中存在的主要问题。     

我国优秀棒球投手上肢运动的检测分析

目的:以探讨棒球投手肩关节旋转运动特征.方法:通过应用一种超声波动力学测量仪和等速仪器分别对25名棒球投手和25名自愿者肩关节内、外旋活动范围(range of motion,ROM)、内外旋肌力进行测量.结果:棒球投手优势臂的外旋活动范围明显大于非优势臂,而其优势臂的内旋活动范围则显著小于非优势臂,优势臂的整个旋转活动范围也明显比非优势臂小;对照组的优势臂和非优势臂旋转活动范围差异无显著性,棒球投手肩关节存在内、外旋肌力不平衡,实验组优势臂内旋IR(210°/s)、IR(300°/s)相对峰力矩明显大于非优势臂(P＜0.001),优势臂外旋ER(210°/s)、ER(300°/s)峰力矩与非优势臂相比,无明显差异(P＞0.05),实验组优势臂外旋/内旋峰力矩比值(ER/IR)明显小于非优势臂.     

幼儿对具初速度物体下落轨迹的预测及其学前教育意义

通过研究幼儿对水平方向具有初速度的物体在失去支撑情况下运动轨迹的预测,从力和运动的角度探究了幼儿的朴素物理理论发展水平.结果表明,幼儿是根据自己的理论作出预测的,他们能在水平方向的运动和垂直方向的运动之间作出积极的"整合",表现出极大的主动性.幼教工作者应该尊重幼儿的已有理论,运用预测等策略,促进幼儿在理论和证据之间积极作出协调.     

二阶曲线切线交点的若干轨迹

利用交比，在仿射平面上，对于二阶曲线，探求交成θ角的两切线的交点的轨迹方程，进而揭示其若干特殊情形．     

The association between lower limb biomechanics and ball release speed in cricket fast bowlers: a comparison of high-performance and amateur competitors

The aim of this study was to compare the associations between lower limb biomechanics and ball release speed in 15 high-performance (HP) and 15 amateur fast bowlers. Kinematic and kinetic variables of the lower limbs collected in the laboratory environment with a 3D Vicon motion analysis system were compared between groups, as well as their associations with ball release speed. HP bowlers had a significantly higher run-up velocity at back foot impact but this difference became non-significant at ball release. Front knee kinematics were not statistically different, however effect sizes revealed medium-large differences with the HP group displaying a more extended knee joint at maximum flexion (d = 0.72) and ball release (d = 0.76). Only front hip positive power was significantly higher in the HP group and it was suggested that the probable cause was the HP bowlers having less knee flexion after front foot impact. From a joint power analysis, the extensor muscle groups of the hip and knee were shown to be important in developing ball release speed. This highlights the need for lower limb/core strength programmes to be multifaceted and focus on the muscles associated with both power and stability.     

Getting at the Mathematics: Sara’s Journal

In this paper, we discuss issues in planning and conducting research into mathematics learning. We emphasize two central themes: (a) the learners mathematics (especially the issues and ideas, in given problem situations, that learners choose to think about and to present) and (b) the kinds of knowledge that learners may be building (including their ideas about what mathematics is, and how people do, learn, use, communicate and understand it). While the first theme is at least partly mathematical, the second interweaves cognition and epistemology. Anchored in student data from an extended classroom teaching experiment in the mathematics of change, we focus on key choices needed to build narratives to help researchers capture, in detail, how students engage with mathematics in extended problem explorations.