论述乒乓球技术中的“爆发力”

本文从怎样搞好乒乓球技术方面入手,根据当前乒乓球运动发展的趋势,对乒乓球的击球力量进行了分析,同时提出了怎样提高击球“爆发力”的方法,强调了“爆发力”在乒乓球技术中的重要作用。     

自由旋转测算粘度新方法的研究

以球体旋转为例提出和说明了不用测量扭矩和转速两种数据的传统方法,而仅采用激光测取自由旋转体角速度一种数据,即可计算出流体内摩擦系数的新的简单方法。     

反曲弓应力、应变最佳分布研究

通过非电量电测技术,利用现代测试手段,就弓上应力、应变的分布进行测试,从而选择了弓上粘贴应变片和加速度传感器的最佳位置,为运动员选弓、调弓选择不同的减震器与动作技术的匹配等方面的研究提供方法原理上的保证.     

浅析工程图学的教学改革

通过对大学工科工程图学教学现状的分析,提出工程图学教学调整的具体内容、改革的具体方法和取得成功的经验。     

用物理方法推导曲率半径公式

采用物理学中直角坐标系加速度和自然坐标系的切向和法向加速度等概念推导曲率半径方程.     

Changing Science Outcomes: Cognitive Acceleration in a US Setting

Inquiry is seen as an integral part of science education in the USA; however, few American science programs explicitly focus on the higher order thinking skills that are the precursors to inquiry. In this paper, Australian researchers report the result of using a version of the Cognitive Acceleration through Science Education (CASE) program in a school district in Oregon (USA) to address teacher-identified concerns about student competence in scientific inquiry. The substantial effect of CASE on British children’s cognitive development and scholastic achievement has been demonstrated convincingly since its inception in the United Kingdom in 1981. The Oregon CASE project was not a mere replication of the original British CASE research: different instruments were employed, and both the measures of cognitive level and student achievement were Rasch-calibrated. The Oregon CASE teachers received comparatively less professional development than did their British counterparts. Neither did they deliver the entire intervention. The results of the study suggest that many of the benefits of CASE still apply when the intervention is conducted in a sub-optimal setting. Cognitive growth was apparent in participating students and high correlations were found between cognitive level and results in some state-mandated tests.     

质点沿水平转盘任一弦运动时加速度的推导

水平转盘以匀角速ω转动，一质点沿盘的直径以匀速率ｖ’作相对运动，在惯性系中考查质点的运动，发现有科里奥利加速度存在。这是一般教科书中常用的手法。本文则从质点沿任一弦这动的情况来引出此项加速度。     

英语学习巧迁移

学习迁移有正负两方面的作用,在母语以外的语言学习中体现尤为明显。语言迁移既包括语间迁移,也有语言内部迁移。在英语学习中,注意引导学生充分利用各种形式的正迁移,防止汉语学习中许多负迁移对英语学习的阻碍作用至关重要;同时,还要引导学生利用好先行学习对后续学习的正迁移作用。     

椭圆规上质点运动与人造卫星运动异同的分析

椭圆上某质点P的椭圆轨迹,其径向加速度恒指椭圆中心。而以椭圆轨迹运行的人造地球卫星,其径向加速度恒指向地球,但地球并非在该轨迹的中心,而是椭圆轨迹的焦点处,两者有相同之处,又有质的差别。本文将通过简单的微、积运算,分析其异同。     

Durand-Kerner算法的5阶加速

基于Durltnd—Kemer算法结构，构造了新的同时求解多项式根的并行算法，且证明了该算法当多项式只有单根时，其收敛阶为5．