提高助跑的准确性

我们的跳远和三级跳远运动员年年都提高了运动成绩,从而走在世界优秀运动员的最前列.但是,他们迄今仍然存在着助跑准确性差这一缺点.捷尔——奥尔涅祥和戈利稚夫在去年的比赛季节中,脚踏板过线的错误占全部跳跃的30-50%.费多谢耶夫和加列也尔也常犯踏板过线或过早起跳的错误.利稚霍夫斯基当助跑不准确时,就会降低成绩20——30厘米.在最优秀运动员当中,助跑较准确的一些的,只有沙波鲁谱娅和波达连柯两人.至于其余的许多运动员的助跑也往往缺乏稳定的准确性.对不准确的助跑进行分析的结果表明,在训练实践中,我们没有采用有效的方法,来帮助运动员把动     

游泳推进力的流体力学分析(续)

这部分的研究目标是对游泳选手划水的各种熟练技能在三度空间里进行分析。所要进行的力量计算,关键在于他们的划臂动作。我们利用手的运动座标给我们表示出手的速率的大小,后掠角度和倾斜角度。函数方程式1和2: L=1/2pV~2C_CS D=1/2pV~2C_DS是可以成立的。这样,力量的计算便是可能的。 方法 分析影片步骤:运用二轴性的技巧获得电影资料。以俯视面和侧视面作为主要的观察平面。通过     

Interaction of wrestling shoe and competition surface: effects on coefficient of friction with implications for injury

The purpose of this study was to determine whether there is a significant difference in the co-efficient of friction (Fc) between old versus new wrestling shoes and mats and to investigate the effect of perspiration. Fc was measured by dragging a weighted shoe over a wrestling mat surface and measuring the vertical and horizontal forces produced. Three different shoe conditions were assessed over two mat types for both wet and dry conditions for a total of 12 conditions. To simulate the wet condition, saline solution was smeared over the surface of the mat. There was a significant effect of shoe, mat, and wet/dry conditions. In addition, significant interactions of shoe by mat, shoe by dry/wet, and mat by dry/wet were observed. Overall, Fc was 36% higher for the new wrestling mat compared to the old wrestling mat. Application of the saline solution reduced Fc by 14% compared to the dry condition. Comparison of the mean Fc for all three shoe types revealed the Fc for the older design shoe was 23% to 28% lower than the brand new shoe and the worn newer design, respectively. A high Fc, such as in the new mat/new shoe combination, has the potential to increase the risk of knee and ankle injuries by fixing the foot more securely to the ground.     

知识服务:在新职业中的文件信息管理工作

一、知识服务作为一种新的职业正在兴起信息管理领域正在兴起一种新职业——知识服务,我们把该职业定位成一种把知识管理、信息管理和战略(以业绩为中心)学习与培训联系到一起的职业。对组织来说,知识服务为企业领域提供了一种保证组织活动成功的管理方法。     

关于乒乓球选材标准的教练员观点调查

本研究的目的是基于乒乓球教练员对人体形态测量、身体素质能力、生理心理素质、心理以及体型因素的基础上,决定选材的原则和标准。这个研究的反馈者包括40名国际水平的乒乓球教练员(26位来自伊朗,14位来自其它国家),他们是随机抽取的,55%的反馈者持有国际教练员资格学位,教练生涯的平均年数是15.74年。大约有50%的认为7～8岁是选材的最合适年龄段;27.5%认为是5～6岁;17.5%认为是9～10岁。根据分析,发现66.5%选择观察方法;48.1%选择科学方法作为选材时优先考虑的方法。总的来说,34.2%认为教育部门对于选材具有最主要的责任。进一步而言,涉及…     

气候·人类·地球

随着工业化进程脚步的加快,现代化痕迹遍布生活的每个角落,同时人类也不得不面临现代化生产给自然气候带来的不容忽视的严重影响。我们在渐渐失去冬天……     

明星与政治

Bono vs.Pretty Much Eyerything博诺vs .几乎每件事Bono befriends O’Neill and Ghana President JohnKufuor. His Case:You name it,he’s trying to fix it:hunger,education,health care,orphans,whatever makes peopleunhappy;lately,he's pushing debt relief for the ThirdWorld nations and stopping the spread of AIDS in Africa.