点的合成运动的讨论

本通过对点的合成运动的讨论，着重提出了解题难点、要点和注意点，并通过典型例题进行了进一步说明。     

体育投资与国民经济增长论证

本文运用经济学有关原理 ,采取演绎法、逻辑推理法、计量分析法等方法对体育投资促进经济增长的机理进行研究 ,并提出加大体育投资、发展国民经济相关的对策。     

艾里光束在超常介质中的传输特性

艾里光束(Airy beam)是近年来备受关注的新型无衍射激光束之一,艾里激光束具有自由加速、无衍射及自愈等奇异特性,并具有重要应用前景。超常介质为人工微结构材料,它使人们具备按需要设计介质参数的能力。基于一维光束传输方程,获得了超常介质中艾里光束复振幅传输解析表达式。数值计算结果表明,超常介质中艾里光束振幅的大小与在正常介质中完全相同,而振幅的虚部和相位正好相反。所得结果为人们操控艾里光束提供支持。     

面向单元内加速的可重构算法设计

为了能够在可编辑逻辑器件上设计更高速度的功能单元,提出了一种面向单元内加速的可重构算法。通过该算法能够对目标逻辑功能单元进行功能重构,并以缩短单元内部逻辑门的层数,以及单元内逻辑门的控制结构,实现单元内加速。选取了典型的可重构计算单元,分析了应用本文所设计的可重构算法对逻辑功能单元进行重构设计。测试中,经过重构设计后的计算单元,运行时间最多减少了30%。     

浅谈拓展训练在中学体育教学中的运用

21世纪是知识经济的时代,每个人都要面临知识的不断更新,中学体育教学也面临着由传统体育向新兴体育的转变。当今的体育教学在“健康第一”的指导思想下,关于课程、教学模式、教学内容等诸多方面的改革正在如火如荼地进行,其最终目标就是培养高智商、高情商,从而使现代青少年能够更快适应飞速发展的社会。根据新课改的要求,在学校体育课中除传授一些基本知识外,还应注重学生坚强的心理品质、良好的社会适应能力的培养。而拓展运动对学生健康、创新、心理品质等诸多方面都有很大的意义。     

Perfectionism and Goal Orientations Among Chinese Gifted Students in Hong Kong

Positive and negative perfectionism as well as four goal orientations were assessed in a sample of 315 Chinese gifted students in Hong Kong. These students tended to endorse positive perfectionism more than negative perfectionism and prefer learning and social goals over performance and avoidance goals. Learning and social goal orientations emerged as significant predictors in the prediction of positive perfectionism, whereas performance and avoidance goal orientations emerged as significant predictors for negative perfectionism. Implications of the findings for promoting healthy strivings for excellence through setting different goals are discussed.     

用倾斜气轨系统与Spss测定重力加速度

用垫块调整气轨的倾斜角,使滑行器在自身重力作用下沿气轨表面直接做功,使用智能计时系统精准测出滑块在气轨斜面定点位置的速度。由测量原理及不确定度分析,对照测量数据,引入Spss的曲线估计功能分析得到速长综合量与垫块高度的定标曲线,并验证出速长综合量与垫块高度存在线性关系,由此标定出重力加速度,并用置信概率为95%的不确定度对其进行了合理的分析和评定,得到更加合理的实验结果。     

拓展训练在高职院校贫困学生心理素质教育中的应用

拓展训练是一种通过体验、分享、总结,达到提升心理素质的体验式学习。对高职院校中的贫困学生群体开展拓展训练能够促进其身心健康发展、提高个人执行能力、完善人格、提升人际交往能力。高职院校通过设置分阶段、分层次的拓展训练课程体系,设计有针对性的拓展训练课程,建立个体的跟踪式教学模式,设计针对不同专业和职业的拓展训练课程,有利于加强高职院校贫困学生心理素质教育。     

基于虚拟仪器的减振效果分析系统设计

该文采用自行设计的三维加速度传感器和虚拟仪器技术开发了减振效果分析系统,具有在线实时分析、离线分析、加速数据流回放、一键生成减振效果分析报表等功能,具有界面直观、操作简单、易于扩展的特点,系统测量分析准确,运行稳定,为检验减振装置的减振效果提供了依据。     

Using accelerometry to quantify deceleration during a high-intensity soccer turning manoeuvre

Abstract

The mechanics of cutting movements have been investigated extensively, but few studies have considered the rapid deceleration phase prior to turning which has been linked to muscle damage. This study used accelerometry to examine the influence of turning intensity on the last three steps of a severe turn.

Ten soccer players performed 135° “V” cuts at five different intensities. Resultant decelerations were recorded from a trunk-mounted tri-axial accelerometer. Lower limb kinematics and ground reaction forces (GRF) from the pivot foot-ground contact (FGC) were also monitored.

Average peak trunk decelerations were larger at the two preceding steps (4.37 ± 0.12 g and 4.58 ± 0.11 g) compared to the PIVOT step (4.10 ± 0.09 g). Larger peak joint flexion angular velocities were observed at PRE step (ankle: 367 ± 192 deg.s^?1; knee 493 ± 252 deg.s^?1) compared to PIVOT step (ankle 255 ± 183 deg.s^?1; knee 377 ± 229 deg.s^?1). Turn intensity did not influence peak GRF at PIVOT step.

This study highlights the importance of steps prior to turning and their high-frequency loading characteristics. It is suggested that investigations of lower limb loading during turning should include this deceleration phase and not focus solely on pivot FGC.