数学归纳法教学中的逻辑因素分析

数学归纳法应用非常广泛,但实际教学中学生难于掌握,本文试图通过分析,理清逻辑思路,借助多米诺骨牌游戏,将抽象的数学知识直观地反映出来,帮助学生弄清数学归纳法的本质。     

特殊级数↑∞∑↓（n=1） （-1）^（n-1）/（2n-1）^（2k-1）与π^（2k-1）的关系

根据傅立叶级数的性质，得到并运用数学归纳法证明了某一类特殊级数与π之间的关系。     

Childhood Physical Fitness and Performance as Predictors of High School Sport Participation

ABSTRACT

Participation in youth sport is positively associated with physical fitness and performance. The purpose of the current study was to examine if physical fitness measures during childhood and early adolescence predicted high school sport participation. Participants included youth in the Michigan State University Motor Performance Study. Measures consisted of the endurance shuttle run, Wells sit-and-reach, jump and reach, standing long jump, agility shuttle run and 30-yard dash. Individual, generalized estimating equation models were used to estimate the association between each measure and the odds of participating in high school sport. For both sexes, the endurance shuttle run and agility shuttle run were related to sport participation. For boys only, the long jump and 30-yard dash were also associated with sport participation. Better physical fitness and performance across several dimensions in childhood, including those related to motor skills, enhanced the likelihood of sport participation in high school.     

试论科学发现的溯因模式

本文拟从三个方面对科学发现的溯因模式作一系统探讨：概念的提出及其基本模式；从溯因模式与归纳、演绎模式的区别看溯因推理模式的本质特征；溯因模式在科学活动中的应用价值与功能。     

FP1可编程序控制器控制多轴步进电机的实现

介绍由可编程序控制器组成的多轴步进电机控制系统的工作原理 ,松下FP1系列可编程序控制器与AT89C2 0 5 1单片机接口电路和软件系统的设计方法。     

机动车交通事故损害赔偿责任的构成要件研究

我国机动车交通事故损害赔偿责任的构成要件,除包括机动车交通事故致人损害事实、机 动车交通事故致人损害行为的违法性,以及机动车侵权行为与损害事实之间的因果关系等一般要件,还 应包括道路要件、车辆要件、交通要件和人身损害赔偿要件等特别要件。     

关于变频调速的应用与节能分析

文章通过分析变频器调速的节能原理,并结合一个热电厂的变频器改造后的实例,阐述了变频调速的节能效果,提高了设备运行可靠性和节能降耗性。     

The key to success in elite athletes? Explicit and implicit motor learning in youth elite and non-elite soccer players

In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10–12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.     

立定跳远教学中TGMD-2的应用研究

目的:对立定跳远教学进行干预,采用儿童大肌肉群动作发展测试量表(以下简称TGMD-2量表)进行过程性测量,观察干预教学对儿童立定跳远动作发展的影响,寻求发展儿童下肢大肌肉群的有效途径。方法:1)干预前后使用TGMD-2量表对学生立定跳远动作进行评分,并测量远度,进行比较;2)对实验组立定跳远教学进行干预,对照组不做干预。结果:实验组立定跳远评分与远度测量显著提高;对照组评分显著下降,远度测量上升。结论:1)运动干预可以促进儿童立定跳远动作发展;2)儿童动作发展成熟之前可采用TGMD-2量表进行过程性评价。     

抗磁性起源的两种经典解释

某些物质在外磁场作用下 ,呈现出抗磁性 ,现在的教材中对抗磁性起源主要是用电子轨道进动和电磁感应两种经典解释。论文对两种结果等效性作论证并予讨论