肌肉力量连续统一体理论及其在力量训练中的应用研究

通过对肌肉力量中主动张力和被动张力的关系所作的深入探讨,认为肌肉在不同收缩形式和收缩速度下,肌力的组成以及各组成成分之间既相互区别又相互联系,形成一个连续统一体。这为力量训练理论与实践研究开辟了新的思路。     

Energy turnover during 24 hours and 6 days of adventure racing

Abstract

Energy turnover was assessed in two conditions of mixed ultra-endurance exercise. In Study 1, energy expenditure and intake were measured in nine males in a laboratory over 24 h. In Study 2, energy expenditure was assessed in six males during an 800-km Adventure race (mean race time 152.5 h). Individual correlations between heart rate and oxygen uptake ([Vdot]O₂) were established during pre-tests when kayaking, cycling, and running. During exercise, energy expenditure was estimated from continuous heart rate recordings. Heart rate and [Vdot]O₂ were measured regularly during fixed cycling work rates to correct energy expenditure for drift in oxygen pulse. Mean energy expenditure was 18,050 ± 2,390 kcal (750 ± 100 kcal · h^?1) and 80,000 ± 18,000 kcal (500 ± 100 kcal · h^?1) in Study 1 and Study 2 respectively, which is higher than previously reported. Energy intake in Study 1 was 8,450 ± 1,160 kcal, resulting in an energy deficit of 9,590 ± 770 kcal. Body mass decreased in Study 1 (?2.3 ± 0.8 kg) but was unchanged in Study 2. Fat mass decreased in Study 2 (?2.3 ± 1.5 kg). In Study 1, muscle glycogen content decreased by only 60%. Adventure racing requires a high energy expenditure, with large inter-individual variation. A large energy deficit is caused by inadequate energy intake, possibly due to suppressed appetite and gastrointestinal problems. The oxygen pulse, comparing start to 12 h of exercise and beyond, increased by 10% and 5% in Study 1 and Study 2 respectively. Hence, estimations of energy expenditure from heart rate recordings should be corrected according to this drift.     

Theoretical Analysis of Aggressive Golf Putts

Abstract

The present study examined the relationship between students' perceptions of the motivational climate and beliefs about the causes of success, preference for challenging tasks, and satisfaction in physical education. Responses of 50 female and 46 male students (M age = 12.08 years; SD = .72) showed that perceptions of a mastery-oriented motivational climate were related to the belief that motivation or effort caused success and satisfaction. In contrast, perceptions of a performance climate were related to the belief that deception caused success and related negatively to the students' preference for challenging tasks. Results of hierarchical regression analyses revealed that perceptions of the motivational climate explained a significant amount of unique variance in the students' responses after controlling for dispositional goal orientations. The results suggest that the teacher can influence the salience of a mastery-oriented climate and, in so doing, optimize a child's motivation in physical education.     

引援的“鲶鱼效应”带来的正能量探析——以北京男排为例

采用文献资料法、专家访谈等研究方法,通过观察、分析,得出,引援产生的"鲶鱼效应"对北京男排的实力及整个排球联赛带来了巨大变化,进而探析"鲶鱼效应"对本土球员、俱乐部、排球联赛各自所带来的的正能量,旨在为中国职业排球联赛及中国男排快速健康发展提供理论参考。     

大孔吸附树脂柱色谱法分离纯化重楼皂苷过程中的质量控制与评价

以重楼根茎粉末为原料,加热回流提取粗皂苷后,用近红外在线检测AB-8大孔吸附树脂除杂和洗脱分离的全过程,并以近红外光谱判别变量为表征手段,将分离过程分为四个阶段。分别对每个阶段收集的洗脱液进行比色和水解,通过离线的紫外光谱和高效液相色谱分析,结果显示,用70%的乙醇对大孔吸附树脂中除杂以后的重楼总皂苷进行洗脱,基本能将重楼总皂苷分为几类有效组分群。     

伯努利方程的原理及运用浅析

伯努利方程原理是流体力学中的一个重要定理,涉及很多流体力学的知识,在现实生活中运用很多。由于一些知识点难以理解,在实际的解题和运用中让一些师生疑惑不解。本文重点剖析了伯努利方程的原理内涵及在现实生活中的一些应用。     

三元能量对谷子S2主要性状的影响

用三元能量对谷子进行了诱变处理，并对Ｓ２的主要性状进行了分析，了解某些数量性状的遗传规律，为谷子育种提供理论依据。     

关于国家能源战略取向的思考

能源战略思维的基本要求是全局性和长远性，必须从国家政治、经济、环境、资源以及建立新型体制等多方面，对国内外因素全面分析。应充分利用现代能源技术的最新成就，着力于构建有中国特色的、适应于未来能源系统发展趋势的新型能源体系，高度关注环境制约对我国能源发展的影响，制定国家能源发展路线图。“供给安全、环境友好、利用高效、经济可靠”应成为我国新时期能源战略的目标取向。     

考虑低碳节能的小城镇居住区规划设计仿真

随着工业化和城市化进程推进,小城镇居住区的低碳节能规划设计关系到城市发展和人们生活健康。考虑低碳节点效果,提出一种基于二氧化碳含量和温度自回归分析的小城镇居住区规划设计模型。模型设计包括了城镇的楼宇建筑设计、绿化景观和风景园林设计等。通过可持续发展的建筑规划选址、合理的土地利用、适宜的功能分区、安全便捷的交通系统等子系统设计完成居住区的整体规划。采用功能分区合并技术,把绿地系统分自然绿地、居住绿地、活动绿地、庭院绿地。规划区域主要分为生活区和活动区、绿色生态区、商业区等四大区域,以光照、温度、湿度和绿化植物的碳吸收和释氧量为自回归参数进行数学建模。充分利用的南向采光和立体采光,使得居住区的光照强度增加。仿真实验结果得出,该模型具有较好的低碳节能效果,居民满意度提高。     

Mathematical Analysis of Energy Efficiency in IEEE 802.11 DCF

The standardized IEEE ,802. II distributed coordination function （ DCF） provides a contention-based distributed channel access mechanism for mobile stations to share the wireless medium. However, when stations are mobile or portable units, power consumption becomes a primary issue since terminals are usually battery driven. This paper proposes an analytical model that calculates the energy efficiency of both the basic and the RTS/CTS access mechanisms of the IEEE 802. II protocol. The model is validated with simulation results using NS-2 simulation package. The effects of the network size, the average packet length, the initial contention window and maximum backoff stages on the energy efficiency of both access mechanisms are also investigated. Results show that the basic scheme has low energy efficiency at large packet length and large network size, and depends strongly on the number of stations and the backoff procedure parameters. Conversely, the RTS/CTS mechanism provides higher energy efficiency when the network size is large, and is more robust to variations in the backoff procedure parameters.