浅谈110kV SF_6封闭式组合电器检修     

卢伟洪 《江西电力职业技术学院学报》2009,22(4)

介绍ZF4A-126型气体绝缘金属封闭开关设备的结构、工作原理、技术参数;总结和介绍110kV SF6封闭式组合电器的检修步骤,检修设备所涉及的SF6气体处理、工艺要求等注意事项及人身安全防护,并提出合理化建议。  相似文献   

DBMS测试浅探   总被引：1，自引：1，他引：0  

胡恩博 《湖南第一师范学报》2009,9(1):166-167

DBMS（数据库管理系统）测试已成为当今庞大的DBMS中一个相对独立、完整,并占有重要地位的过程。应从测试的目的、过程、步骤、文档以及测试分析与调试五个方面进行研究。  相似文献   

建阳市农村生态建设初探     

熊爱国 《宁德师专学报(自然科学版)》1998,(3)

分析建阳市自然生态条件概况与农村生态环境存在的主要问题,阐述该市在农村生态建设中实施的生物、工程、耕作３大调控措施及其所取得的生态、经济、社会效益．  相似文献   

探寻跨栏步教学的优化手段——滑马过栏          下载免费PDF全文

崔冬雪 《河北体育学院学报》2015,29(5):72-75

在整合、分析以往常规教学手段的基础上,依据跨栏步的动作结构、运动生物力学、解剖学和运动心理学原理设计了“滑马过栏”教学手段,该手段由三个分解练习和一个完整练习构成,形成了“一招四步”的教学结构,四步教学依次递进进行,体现了跨栏步技术的连续性。“滑马过栏”教学手段采用了推进式设计,简化了教学流程、针对性强,将跨栏步的不同部分的关键技术明确化,突出了教学重点,解决了教学难点,通过此教学手段的运用,学生掌握跨栏步技术用时明显短于常规教学,且技术掌握准确率较高,是一种有效的跨栏步教学手段  相似文献   

The relationships between step count and all-cause mortality and cardiovascular events: A dose–response meta-analysis     

Mingxin Sheng  Junyue Yang  Min Bao  Tianzhi Chen  Ruixue Cai  Na Zhang  Hongling Chen  Minqi Liu  Xueyu Wu  Bowen Zhang  Yiting Liu  Jianqian Chao 《运动与健康科学(英文)》2021,10(6):620

BackgroundA goal of 10,000 steps per day is widely advocated, but there is little evidence to support that goal. Our purpose was to examine the dose–response relationships between step count and all-cause mortality and cardiovascular disease risk.MethodsCochrane Central Register of Controlled Trials, EMBASE, OVID, PubMed, Scopus, and Web of Science databases were systematically searched for studies published before July 9, 2021, that evaluated the association between daily steps and at least 1 outcome.ResultsSixteen publications (12 related to all-cause mortality, 5 related to cardiovascular disease; and 1 article contained 2 outcomes: both all-cause death and cardiovascular events) were eligible for inclusion in the meta-analysis. There was evidence of a nonlinear dose–response relationship between step count and risk of all-cause mortality or cardiovascular disease (p = 0.002 and p = 0.014 for nonlinearity, respectively). When we restricted the analyses to accelerometer-based studies, the third quartile had a 40.36% lower risk of all-cause mortality and a 35.05% lower risk of cardiovascular event than the first quartile (all-cause mortality: Q1 = 4183 steps/day, Q3 = 8959 steps/day; cardiovascular event: Q1 = 3500 steps/day, Q3 = 9500 steps/day; respectively).ConclusionOur meta-analysis suggests inverse associations between higher step count and risk of premature death and cardiovascular events in middle-aged and older adults, with nonlinear dose–response patterns.  相似文献   

Accuracy of three Android-based pedometer applications in laboratory and free-living settings     

Jia Yan Leong 《Journal of sports sciences》2017,35(1):14-21

This study examines the accuracy of three popular, free Android-based pedometer applications (apps), namely, Runtastic (RT), Pacer Works (PW), and Tayutau (TY) in laboratory and free-living settings. Forty-eight adults (22.5 ± 1.4 years) completed 3-min bouts of treadmill walking at five incremental speeds while carrying a test smartphone installed with the three apps. Experiment was repeated thrice, with the smartphone placed either in the pants pockets, at waist level, or secured to the left arm by an armband. The actual step count was manually counted by a tally counter. In the free-living setting, each of the 44 participants (21.9 ± 1.6 years) carried a smartphone with installed apps and a reference pedometer (Yamax Digi-Walker CW700) for 7 consecutive days. Results showed that TY produced the lowest mean absolute percent error (APE 6.7%) and was the only app with acceptable accuracy in counting steps in a laboratory setting. RT consistently underestimated steps with APE of 16.8% in the laboratory. PW significantly underestimated steps when the smartphone was secured to the arm, but overestimated under other conditions (APE 19.7%). TY was the most accurate app in counting steps in a laboratory setting with the lowest APE of 6.7%. In the free-living setting, the APE relative to the reference pedometer was 16.6%, 18.0%, and 16.8% for RT, PW, and TY, respectively. None of the three apps counted steps accurately in the free-living setting.  相似文献   

体育教育专业足球课程体系的优化实践——兼论课程难度阶梯与体院术科阶梯型课程     

周毅  刘夫力 《广州体育学院学报》1999,(4)

通过体育教育专业普修、专修足球课程的系统研究 ,实现了课程体系中不同层次的教学优化。但对足球课程结构优化、教学内容安排序列优化的研究较为薄弱 ,引入课程难度的概念则解决了足球课程体系整体优化的问题。为此 ,运用现代课程理论的观点 ,系统整合以往零星的研究成果 ,并上升到阶梯型课程理论层次加以探讨 ,以求更好地适应各类专业教学计划更改对足球课程提出的要求  相似文献   

背越式跳高最后两步助跑对跳高成绩影响的实验研究     

庞庆军  李银萍  李龙谱 《湖北体育科技》2008,27(1):49-50

运用文献资料法、数理统计法和教学实验法,对实验班进行为期4学时（一个月）的背越式跳高最后两步助跑对跳高成绩影响的教学实验研究。结果表明：最后两步助跑对背越式跳高成绩有显著影响;加强最后两步助跑技术,对整个背越式跳高技术的完善,包括动作的规范性、可控制性和可操作性起到积极的促进作用。  相似文献   

论博尔特的运动天赋与勤奋     

左威 《湖北体育科技》2009,28(2):177-178,176

在北京奥运会百米决赛中,牙买加人博尔特以9秒69惊人的成绩,创造了人类百米新纪录,以自己的勤奋自觉训练行为,对“超高身材”的运动员,不宜择选100m跑项目传统意识的否定。现实证明,以人为本,用科学发展观,凭着“天赋”＋“勤奋”,以及接受科学训练,即可为实现目标的保证。  相似文献   

对提高铅球滑步与最后用力快速衔接的专项训练手段的研究     

李岳峰  李亚俊  李再兴 《湖北体育科技》2004,23(2):237-239

根据运动生物力学、运动心理学原理，从构成铅球运动员滑步与最后用力衔接的关键要素出发，设计了与之密切相关的6种主要专项训练手段，并进行有序地组合，形成针对性强，且综合功效显的系统整体。经实践证明，该训练手段的综合运用有效促进了铅球运动员滑步与最后用力的衔接，加快了完成动作的速度，提高了投掷成绩。  相似文献