Sex differences in lower extremity stiffness and kinematics alterations during double-legged drop landings with changes in drop height

The aim of this study was to determine whether sex differences and effect of drop heights exist in stiffness alteration of the lower extremity during a landing task with a drop height increment. Twelve male participants and twelve female participants performed drop landings at two drop heights (DL40 and DL60; in cm). The leg and joint stiffnesses were calculated using a spring–mass model, and the joint angular kinematics were calculated using motion capture. Ground reaction forces (GRFs) were recorded using a force plate. The peak vertical GRF of the females was significantly increased when the drop height was raised from 40 to 60 cm. Significantly less leg and knee stiffness was observed for DL60 in females. The ankle, knee, and hip angular displacement during landing were significantly increased with drop height increment in both sexes. The knee and hip flexion angular velocities at contact were significantly greater for the 60 cm drop height relative to the 40 cm drop height in males. These sex disparities regarding the lower extremity stiffness and kinematics alterations during drop landing with a drop height increment would predispose females to lower extremity injury.     

2008年奥运会的税收经济影响分析

运用数量分析和比较文献方法。在综合分析奥运会给北京带来的经济社会影响的基础上，着重分析了奥运会对北京地方税收经济带来的诸方面影响，以及税收政策对成功举办奥运会、发挥奥运经济正面效应、克服奥运经济负面效应中的重大作用。在此基础上，针对当前北京市已经实施的奥运税收政策进行了综合评价。井提出了完善2008年北京市奥运税收政策体系的基本构想。     

幂等的Hemite矩阵与矩阵的分解

研究了任意矩阵的分解与幂等的Hemite矩阵的一些内在的关系。     

建筑围护结构的生命周期清单分析方法

基于生命周期评价的技术框架,提出了建筑围护结构环境影响的清单分析方法,得出典型建筑围护结构整个生命周期内的环境影响清单数据,可以为建筑围护结构的环境影响评价提供参考。     

山西省本科院校面向大学生的体育宣传工作现状研究

体育宣传工作为高校精神文明建设、和谐校园的构建发挥着重要的作用。随着高校体育宣传内容与形式的增加,宣传的作用和效果日益明显,体育宣传工作越来越被人们所重视。作为宣传对象的大学生在接受高校体育宣传的同时必然会受到一定的影响,因此,文章对山西省本科院校体育宣传工作对大学生的影响情况进行了分析和研究,并得出相应结论,以期为相关部门加强和改进高校体育宣传工作提供理论参考。     

Roger Osborne (1940–1985), University of Waikato, New Zealand

This short paper outlines the emergence and achievements of the Science Education Research Unit at the University of Waikato over the period 1979–1985 under the leadership of the late Dr. Roger Osborne. Following his attendance at the ASERA meeting in Wagga Wagga in 1977, Roger Osborne rapidly built up a very productive team, which he led until his death in 1985. His legacy is tentatively evaluated. In conclusion, the cultural context in which this work took place is sketched.