Are gait characteristics and ground reaction forces related to energy cost of running in elite Kenyan runners?     

J. Santos-Concejero  N. Tam  D. R. Coetzee  J. Oliván  T. D. Noakes  R. Tucker 《Journal of sports sciences》2017,35(6):531-538

The aim of this study was to determine whether gait cycle characteristics are associated with running economy in elite Kenyan runners. Fifteen elite Kenyan male runners completed two constant-speed running sets on a treadmill (12 km ·h^?1 and 20 km ·h^?1). VO₂ and respiratory exchange ratio values were measured to calculate steady-state oxygen and energy cost of running. Gait cycle characteristics and ground contact forces were measured at each speed. Oxygen cost of running at different velocities was 192.2 ± 14.7 ml· kg^?1· km^?1 at 12 km· h^?1 and 184.8 ± 9.9 ml· kg^?1· km^?1 at 20 km· h^?1, which corresponded to a caloric cost of running of 0.94 ± 0.07 kcal ·kg^?1·km^?1 and 0.93 ± 0.07 kcal· kg^?1· km^?1. We found no significant correlations between oxygen and energy cost of running and biomechanical variables and ground reaction forces at either 12 or 20 km· h^?1. However, ground contact times were ~10.0% shorter (very large effect) than in previously published literature in elite runners at similar speeds, alongside an 8.9% lower oxygen cost (very large effect). These results provide evidence to hypothesise that the short ground contact times may contribute to the exceptional running economy of Kenyan runners.  相似文献   

带电粒子在磁场中的运动和能量     

刘益民 《青海师专学报》2001,21(6):20-23

研究了带电粒子分别在均匀磁场、均匀变化磁场中的运动和能量。  相似文献   

Is students’ energy literacy related to their university’s position in a sustainability ranking?     

D. R. E. Cotton  J. Winter  W. Miller  L. Dalla Valle 《Environmental Education Research》2018,24(11):1611-1626

Abstract

University rankings are increasingly important internationally, and in the UK include a sustainability ‘Green League’. However, there is little evidence about experiences of studying in ‘sustainable universities’. We report an empirical study at five universities in varied positions in the Green League, exploring students’ energy literacy, environmental attitudes and perceptions of their institution’s energy-saving efforts. Although the link to energy literacy is not clear, findings suggest that there are significant differences between students’ environmental attitudes at universities placed at different points in the league. In addition, students at higher ranked universities are more positive about their university’s energy-saving efforts, suggesting that these institutions may exhibit more overt manifestations of sustainability. This is important since students report being more likely to choose energy-conservation behaviours if there is visible representation of energy use. The study is the first to attempt a comparison between universities at different positions in a sustainability ranking.  相似文献   

浅谈无功就地补偿     

赵彦婷  崔好军 《安阳师范学院学报》2002,(2):100-101

分析了就地补偿原理，介绍了补偿容量的选择方法，阐述了就地补偿的效益及其应用场合。  相似文献   

梅园节肢动物群落优势种分析     

黄保宏  邹运鼎  毕守东  巫厚长  胡洪洲 《安徽科技学院学报》2007,21(1):27-30

应用系统调查和能流量法分析了梅园节肢动物群落优势种,结果表明:不论数量和能流量分析,梅园节肢动物群落的主要害虫优势种均为朝鲜球坚蚧和桃蚜;而天敌优势种数量和能流量分析分别为黑缘红瓢虫、红点唇瓢虫和黑缘红瓢虫、草间小黑蛛.  相似文献   

100m跑理论研究的新动向     

李相如 《浙江体育科学》1998,(2)

本文主要介绍了意大利运动理论和方法论专家ＥｌｉｏＬｏｃａｔｅｌ,和法国著名的运动生理实验室专家ＬａｕｒｅｎｔＡｒｓａｃ关于１００ｍ跑的机械效率和能量学研究的成果,并对此谈几点启示。  相似文献   

我国复印机、打印机和传真机能效测试方法研究     

谢磊雷  王世栩  陆永丽  忻龙  谢肖 《中国科技纵横》2015,(3)

GB21521-2014《复印机、打印机和传真机能效限定值及能效等级》将于2015-01-01实施,新版标准的限值相比原版标准有了大幅度的提高,测试方法也做出相应调整,本文通过分析新版标准的测试方法,介绍了检测项目及技术要求,并提出在测试过程中应该注意的事项。  相似文献   

云创新:新能源汽车产业发展新模式——以比亚迪新能源汽车为例     

王洪生  张玉明 《科技管理研究》2015,(23)

云创新模式是基于互联网背景下更加开放的开放式创新,具有低成本、高效率等显著特征。在总结梳理云创新相关理论基础上,分析新能源汽车产业发展现状,应用云创新的动力机制以及云创新发展模式,并以比亚迪新能源汽车应用云创新活动进行说明,从而为云创新模式在新能源汽车产业的应用提供有益的参考。  相似文献   

中国物流业能源消耗、碳排放与行业发展关系分析     

张立国  李东 《科技管理研究》2015,(24)

以我国物流业为研究对象,对其能源消耗、碳排放和产业发展特征进行分析,并利用Tapio脱钩分析技术对2003—2012年我国物流业的能源消耗、碳排放和行业发展情况进行了脱钩分析。结果表明,2003—2012年,我国物流业的能源消耗、碳排放的增长率要大于行业发展的增长率,三者均在样本年内呈现出了增长的趋势;行业发展与碳排放和能源消耗基本都呈现出扩张性负脱钩关系,表明我国物流业目前的节能减排形势很不乐观,行业的能源浪费和无效排放问题还比较严重;减排弹性指标近年来表现较好,主要原因是近年来国家相关物流政策的出台。  相似文献   

《能源化学》提高国际影响力的方法分析     

张丽娟 《中国科技期刊研究》2015,26(7):678-682

摘 要 【目的】探讨科技期刊国际化发展的新举措,以期对我国科技期刊国际影响力的提高提供参考。【方法】采用文献研究、比较研究和归纳分析的方法,以《能源化学（英文）》发展沿革的历史为切入点,对我国科技期刊提高国际影响力的具体方法进行了分析和探讨。【结果】 经过近八年努力,期刊在Journal Citation Reports(JCR)的Energy & Fuels和Chemistry (Applied) 分类中位于Q2区;自2011年起,SCI影响因子逐年提高,2013年升至1.788,连续四年在中国化学类及能源类期刊中名列前茅。【结论】学术期刊应该深化期刊改革,立足国内,放眼国际,以提高稿件质量为核心,优化办刊流程,不断提高期刊的国际影响力。  相似文献