速度滑冰的蹬冰力

在速度滑冰中,成绩与运动员每次蹬冰所产生的功量和蹬冰的频率乘积有关。运动员每次蹬冰所做的功取决于与滑行方向垂直的蹬冰力的分力。通过对三个受过训练的速滑运动员测试,测定他们在不同速度时的蹬冰力。结果表明;在不同的速度时,最大的蹬冰力与平均蹬冰力并不改变。而且速度越大,蹬冰时间越短。由此可见,速滑运动员并不是通过改变蹬冰力的大小,而是通过改变蹬冰时间来调节速度。蹬冰力——时间曲线的图形形状取决于蹬冰技术,并且直道滑行与弯道滑行的曲线形状也有区别。速度滑冰的成绩与运动员用于克服空气和冰面摩擦阻力的外功P。密切相关(Ingen Schenau)。外功P。等于每次蹬冰     

血样贮存对血乳酸浓度的影响

本文研究了贮存2～6周的血样乳酸浓度的变异性，采200米跑后即刻指尖血样，用EDTA，三硝基甲苯X－100溶血及NaF抗酵解处理，分别在采血后即刻2周，4周，6周对样本进行血乳酸分析，对各组数据进行方差分析F2216＝16．26P＜0．01，说明贮存6周以上对血乳酸浓度有显著性影响。     

后现代侏罗纪——探索《金刚》的冒险世界

2005年12月14日,我们又将等待一场巨型“灾难”的来临。挥别了《指环王》的魔幻世界,彼得·杰克逊又将给观众搭建一个有复古纽约也有原始森林的冒险世界。《金刚》能否大闹世界影坛?我们拭目以待!     

教育学知识的哲学——分析、批判、建议[特约稿]

在世界上,存在着教育以及种种关于教育的命题体系(Satzsysteme)。教育是一种行为的形式,一种实践。就“理论”一词的广义而言,一种谈论或描述教育的命题体系就是一种教育理论。 所有的教育理论[“教育学(Padagogik)”,英文为“educology”]本身都可以成为描述、批判和规范探讨的对象。也就是说存在教育理论的认识论或者——简而言之——教育的元理论(Metatheorie der Erziehung)”[“元教育学(Meta-Padagogik)”;英文为:“meta-edu     

Experimental study on the inhibition of biological reduction of Fe(III)EDTA in NO x absorption solution

Scrubbing of NO _x from the gas phase with Fe(II)EDTA has been shown to be highly effective. A new biological method can be used to convert NO to N₂ and regenerate the chelating agent Fe(II)EDTA for continuous NO absorption. The core of this biological regeneration is how to effectively simultaneous reduce Fe(III)EDTA and Fe(II)EDTA-NO, two mainly products in the ferrous chelate absorption solution. The biological reduction rate of Fe(III)EDTA plays a main role for the NO _x removal efficiency. In this paper, a bacterial strain identified asKlebsiella Trevisan sp. was used to demonstrate an inhibition of Fe(III)EDTA reduction in the presence of Fe(II)EDTA-NO. The competitive inhibition experiments indicted that Fe(II)EDTA-NO inhibited not only the growth rate of the iron-reduction bacterial strain but also the Fe(III)EDTA reduction rate. Cell growth rate and Fe(III)EDTA reduction rate decreased with increasing Fe(II)EDTA-NO concentration in the solution. Project (No. 20176052) supported by the National Natural Science Foundation of China and the Scientific Research Foundation for Returned Overseas Chinese Scholars, Ministry of Education     

Modifications in children's goals when encountering obstacles to conflict resolution

Previous studies have demonstrated that children's goals are associated with their success in peer relationships. The current study extends earlier findings by examining changes in children's goals during hypothetical conflicts. Participants were 252 children ages 9 to 12 years old (133 boys, 119 girls). As predicted, children's goals changed significantly when they encountered obstacles to conflict resolution, and these changes were predictive of their subsequent strategy choices. Both aggressive- and submissive-rejected children were more likely to evidence antisocial changes in their goals, including an increased desire to retaliate. They also showed reluctance to forego instrumental objectives. Other findings highlighted the need to investigate the combinations of goals children pursue as predictors of their strategies and the quality of their peer relationships.