高空抛物侵权责任质疑——以连带责任制度为视角

连带责任制度,是《侵权责任法》将高空抛物行为定性为特殊侵权行为的重要依据。高空抛物侵权行为适用连带责任,在理论上缺乏正当性;在现实的利益权衡中,也不能实现利益均衡,不利于实现社会的公平和正义。高空抛物侵权行为属于一般侵权行为,应当适用《侵权责任法》中的一般规定,无须单独立法。     

大力掷界外球的重要性及其训练方法

应用实验法以广西师范大学足球队为例进行实证研究,运用数理统计法对所得出的数据进行分析,发现对足球运动员进行上肢和协调性的专门练习可以加大投掷界外球的力量与距离并丰富足球比赛当中在对方半场前30米区域的进攻手段。     

火电厂补给水系统水锤模拟计算研究

简要介绍了水锤计算的理论依据,采用计算机软件模拟火力发电厂补给水系统停泵水锤瞬态过程,重点对采用液控碟阀和空气阀作为事故停泵水利过渡过程防护的可能性进行了分析与论证．研究结果表明,合理设置液控碟阀关闭规律,结合系统合理设置空气阀的措施,能很好地避免水柱分离的发生．     

Kinematic comparison of the seoi-nage judo technique between elite and college athletes

This study sought to identify biomechanical factors that determine fast and skilful execution of the seoi-nage (shoulder throw) technique by comparing kinematics between elite and college judo athletes. Three-dimensional motion data were captured using a VICON-MX system with 18 cameras operating at 250 Hz as three male elite and seven male college judo athletes performed seoi-nage. No significant difference was found in motion phase time of the turning phase between the two groups, indicating that motion phase time is not necessarily a factor contributing quickness in seoi-nage. The maximum relative velocity of the whole body centre of mass along the anterior–posterior direction was significantly greater in the elite athletes (2.74 ± 0.33 m/s) than in the college athletes (1.62 ± 0.47 m/s) during the turning phase (p = 0.023). The overall angular velocity of the body part lines, particularly the arm line, tended to be greater in the elite athletes (p = 0.068). The results imply that the velocity of the thrower relative to the opponent in the forward drive and turning motion reflects high skill seoi-nage. Coaches should recognise the relative forward velocity as a factor that may contribute to a successful seoi-nage when teaching the judo throw technique.     

中外优秀女子链球运动员旋转及最后用力技术的比较分析

采用2台JVC9800高速摄影机,对中国部分优秀女子链球运动员的投掷技术进行拍摄和解析,并对旋转阶段的时间特征、链球加速距离、链球远行斜面变化等进行运动学分析与比较。     

我国奥运女子新兴田赛项目的忧虑与思考

运用文献资料和调查访问等方法，对我国女子三级跳远、撑杆跳高和链球三项新兴田赛项目开展的现状进行了较为系统的分析。研究指出，我国女子新兴田赛项目担纲运动员年龄偏大，专业队伍和后备力量的规模过小，以及国内竞赛没有与国际竞赛接轨等，已成为制约我国女子新兴田赛项目发展的主要因素。建立和完善促进我国女子新兴项目发展的训练和竞赛体制，已成为当务之急。     

Comparison of kinematics in skilled and unskilled arms of the same recreational baseball players

Abstract

We examined mechanisms of coordination that enable skilled recreational baseball players to make fast overarm throws with their skilled arm and which are absent or rudimentary in their unskilled arm. Arm segment angular kinematics in three dimensions at 1000 Hz were recorded with the search-coil technique from the arms of eight individuals who on one occasion threw with their skilled right arm and on another with their unskilled left arm. Compared with their unskilled arm, the skilled arm had: a larger angular deceleration of the upper arm in space in the forward horizontal direction; a larger shoulder internal rotation velocity at ball release (unskilled arms had a negative velocity); a period of elbow extension deceleration before ball release; and an increase in wrist velocity with an increase in ball speed. It is suggested that some of these differences in arm kinematics occur because of differences between the skilled and unskilled arms in their ability to control interaction torques (the passive torque at one joint due to motion at adjacent joints). It is proposed that one reason unskilled individuals cannot throw fast is that, unlike their skilled counterparts, they have not developed the coordination mechanisms to effectively exploit interaction torques.     

论资本市场信息披露机制的建设

在资本市场上，信息披露是投资者了解上市公司、证券监管机构监管上市公司的主要途径，信息披露制度是各国证券法律制度的重要原则。资本市场信息披露机制建设的基本理论依据是“有效资本市场理论”。美国、法国等西方发达国家资本市场信息披露机制建设的经验可以给我们很好的启发。资本市场信息披露机制的建设首先要进一步完善法律建设，其次要进一步完善执法体系，第三要进一步完善公司的治理结构，第四要进一步完善政府监管模式。     

Baseball

The purpose of this study was to quantify and compare kinematic, temporal, and kinetic characteristics of American and Korean professional pitchers in order to investigate differences in pitching mechanics, performance, and injury risks among two different cultures and populations of baseball pitchers. Eleven American and eight Korean healthy professional baseball pitchers threw multiple fastball pitches off an indoor throwing mound positioned at regulation distance from home plate. A Motion Analysis three‐dimensional automatic digitizing system was used to collect 200 Hz video data from four electronically synchronized cameras. Twenty kinematic, six temporal, and 11 kinetic variables were analyzed at lead foot contact, during the arm cocking and arm acceleration phases, at ball release, and during the arm deceleration phase. A radar gun was used to quantify ball velocity. At lead foot contact, the American pitchers had significantly greater horizontal abduction of the throwing shoulder, while Korean pitchers exhibited significantly greater abduction and external rotation of the throwing shoulder. During arm cocking, the American pitchers displayed significantly greater maximum shoulder external rotation and maximum pelvis angular velocity. At the instant of ball release, the American pitchers had significantly greater forward trunk tilt and ball velocity and significantly less knee flexion, which help explain why the American pitchers had 10% greater ball velocity compared to the Korean pitchers. The American pitchers had significantly greater maximum shoulder internal rotation torque and maximum elbow varus torque during arm cocking, significantly greater elbow flexion torque during arm acceleration, and significantly greater shoulder and elbow proximal forces during arm deceleration. While greater shoulder and elbow forces and torques generated in the American pitchers helped generate greater ball velocity for the American group, these greater kinetics may predispose this group to a higher risk of shoulder and elbow injuries.     

女子链球运动员冬季准备期前后的等速测试

通过对两名高水平女子链球运动员双侧的髋关节和膝关节进行等速测试,探究运动员髋关节和膝关节周围肌群的生物力学特性,为运动训练和运动康复等提供理论依据。利用等速肌力测试系统对两名运动员的髋关节和膝关节屈伸肌群以及髋关节的旋内旋外肌群进行等速测试。结果发现:两名运动员双侧髋关节和膝关节屈伸肌群以及髋关节的旋内旋外肌群的峰力矩随测试速度的增加呈递减趋势,髋膝关节峰力矩屈伸比和髋关节旋内旋外比随既定测试速度的增加呈递增趋势;同一测试速度下,伸肌肌群的峰力矩大于屈肌肌群,髋关节旋外肌群的峰力矩大于旋内肌群。