青少年足球运动员的速度力量训练

速度力量是速度与力量的综合表现 ,它的提高受速度素质与力量素质的牵制。力量和速度是青少年足球运动员快速能力的决定因素。速度力量的典型表现形式是爆发力、起动力、反应力。提出青少年足球运动员力量素质发展的敏感期与必要性 ,对速度力量的理论与实践作了概述。     

世界竞走运动(1991～1998年)发展的状况分析及展望

对1991-1998年、1991-1995年、1996-1998年各阶段世界竞走运动的发展状况进行了分析,结果表明:1995年底竞走定义的修改并未对世界竞走运动的发展产生不良影响,反而更加促进了世界竞走运动的健康发展.展望今后世界竞走运动发展的新思路:充分利用竞走运动的特殊性和人体生物力学界限标准及比赛中裁判员的判罚界限标准进行训练和比赛;改善和提高训练、比赛的方法、手段,特别是高原训练的方法、手段;完善赛前运动员运动能力的控制和比赛中走动节奏的控制;更加重视科学选材及心理训练和恢复训练等都将是今后世界竞走运动发展的趋势.     

试卷质量和考试成绩评判指标的分析研究

本文对试题警告系数、考试成绩的信度、考试成绩的效度及学生警告系数的计算式做了修正 ,使之能适合计算机处理。提出试卷平均得分、试卷区分度、试卷警告系数和学生试卷得分度评判指标 ,使试卷质量 ,教学质量和学生学习水平的评判量化 ,可用于教学评估     

现代跳远运动员的速度训练

跳远的起跳技术由打击型、制动型已经发展成速度型(跑步型)。为了适应这种技术,应该重新认识现代跳远运动员的速度训练,它包括发展运动员跑的速度(跑的能力、绝对速度、助跑速度),速度性力量和快速跳跃能力。     

Exploring mechanisms of rapid automatized naming to arithmetic skills in Chinese primary schoolers

Rapid automatized naming (RAN) is associated with children's arithmetic performance, which is multifactorial by nature and consists of arithmetic fluency, arithmetic procedure, and word problems. Yet, it is unclear whether RAN can predict all key aspects of arithmetic skills independently and what cognitive mechanisms may explain this relation. Using a sample of Chinese primary school students (N = 170), results showed that while RAN was associated with all key aspects of arithmetic skills, the relations of RAN–arithmetic procedure and RAN–word problems may be dependent on that of RAN–arithmetic fluency. Supporting the processing speed hypothesis, results further suggested that processing speed may underlie the relation between RAN and arithmetic performance. Findings made unique contribution to understanding the effect of RAN on arithmetic performance and cognitive mechanisms that may underpin this association in the context of Chinese culture.     

Key somatic variables associated with,and differences between the 4 swimming strokes

ABSTRACT

This study identified key somatic and demographic characteristics that benefit all swimmers and, at the same time, identified further characteristics that benefit only specific swimming strokes. Three hundred sixty-three competitive-level swimmers (male [n = 202]; female [n = 161]) participated in the study. We adopted a multiplicative, allometric regression model to identify the key characteristics associated with 100 m swimming speeds (controlling for age). The model was refined using backward elimination. Characteristics that benefited some but not all strokes were identified by introducing stroke-by-predictor variable interactions. The regression analysis revealed 7 “common” characteristics that benefited all swimmers suggesting that all swimmers benefit from having less body fat, broad shoulders and hips, a greater arm span (but shorter lower arms) and greater forearm girths with smaller relaxed arm girths. The 4 stroke-specific characteristics reveal that backstroke swimmers benefit from longer backs, a finding that can be likened to boats with longer hulls also travel faster through the water. Other stroke-by-predictor variable interactions (taken together) identified that butterfly swimmers are characterized by greater muscularity in the lower legs. These results highlight the importance of considering somatic and demographic characteristics of young swimmers for talent identification purposes (i.e., to ensure that swimmers realize their most appropriate strokes).     

平稳正态过程反正弦定理在信号谱估计中的应用

本文利用平稳过程反正弦定理估计了信号的相关西数和话密度，实例计算表明本文所述方法与实测结果相当一致。     

倒伏对春小麦品种(品系)籽粒灌浆特性及产量的影响

试验选取三类不同熟期的春小麦品种（品系），在同一时间倒伏后，分期对比测定各品种（品系）倒伏后不同发育阶段的籽粒鲜重、干重，比较分析品种（品系）倒伏与未倒伏籽粒的灌浆特性及干物质积累变化规律。结果表明：倒伏对不同品种（品系）籽粒干物质积累动态变化的差异显著性影响不同，对同一品种（品系）的最大灌浆速率及到达最大灌浆速率的时间均存在着影响，最终对籽粒产量存在着不同程度的影响。     

英语阅读中存在的问题及阅读技巧

阅读课程的目的在于提高学生的阅读理解能力和阅读效率。要提高阅读理解能力和阅读效率，就需使读者克服一些不良的阅读习惯，掌握正确的阅读技巧。采用整体法阅读会大大改善学生的阅读速度和阅读质量。     

电磁力测量试验台的设计

从试验台的结构特点和工作流程入手,介绍了其液压系统的工作原理及特点。实践证明:该系统设计合理、工作可靠、调节控制灵活方便。