伦敦奥运周期女子平衡木比赛的特点

以3届世界大赛女子平衡木决赛运动员为研究对象,对伦敦奥运周期世界女子平衡木比赛特点进行研究。结果表明:平衡木成套动作的难度(D分)是获得胜利的基础,获得奖牌选手的D分要达到6.5分以上,且继续提高难度的空间较小;成套动作的结构呈现上法简单化与下法多样化特征;单个技巧动作中,向前空翻和向侧空翻占9成,而后空翻在技巧连接中居多;运动员完成动作的稳定性和动作幅度仍有较大的提升空间,或将成为获得优异成绩的关键;选手之间的实力越来越接近,比赛结果的不确定性增加。     

Learning in Retirement and Old Age: an agenda for the 21st century

This article is about education and learning for the ‘retired’. In using this term, it is recognised that any such definitions and given age bands cover a wide range of situations and learning needs. Such diversity should closely inform the educational agenda for older adults, and as it is a life phase defined by challenge and change ‘learning to be’ encapsulates much that is essential to that agenda. The international evidence shows how rapidly our societies are ageing, and how much longer is spent in retirement: so rapid is that change and so large the numbers of seniors and the elderly that the active nature of learning represents a critical aspect of response to this major phenomenon. Contrary to a popular image of declining skills and capacities, the evidence reveals a much more nuanced picture of capability among the retired. Comparisons are drawn with the early childhood sector, which had parallel characteristics but which has since moved rapidly upwards among policy priorities. In conclusion, the article argues that ‘active ageing’ rather than ‘lifelong learning’ represents a more promising embracing framework through which to develop learning in retirement and old age.     

基于ARM7的电梯轿顶CAN通讯模块的设计与实现

阐述了利用ARM7芯片LPC2119和CANP82C250总线收发器设计了电梯桥顶通讯模块,从硬件和软件两方面构建箱式电梯桥顶通讯模块,该系统改变了原有PLC通讯系统存在的可靠性差等缺点,使得故障停梯时间大大缩短,可靠性明显提高,调试和增减内容均比较方便,达到了预期效果。     

Relationship between performance-based and laboratory tests for lower-limb muscle strength and power assessment in healthy older women

Abstract

The aim of the study was to assess the relationship between performance-based and laboratory tests for muscular strength and power assessment in older women. Thirty-two women aged 68.8 ± 2.8 years were recruited. All participants were asessed for: (a) two performance-based tests – the box-stepping test (mean 296 ± 51 J) and two-revolution maximum test (mean 7.1 ± 2 kg) performed while pedalling on a cycle ergometer; and (b) muscular function tests – maximal instantaneous peak power jumping on a force platform (mean 1528 ± 279 W); maximal voluntary contraction (MVC) during knee extension (mean 601 ± 571 N) and leg press (mean 626 ± 126 N), and leg press power (mean 483 ± 98 W) on a dynamometer. Using univariate analysis, performance-based tests were compared with laboratory muscle strength and power measurements. Muscle power correlated most strongly with the performance-based tests for both jumping and leg press power (r-values between 0.67 and 0.75; P < 0.01). The correlation with muscle strength measures ranged between 0.48 and 0.61 (P < 0.01). The proposed tests may have particular relevance in geriatric and rehabilitation environments as they represent an easy, practical, and inexpensive alternative for the assessment of muscular strength and power.     

An application of the Udwadia-Kalaba dynamic formulation to flexible multibody systems

For the transient response analysis of a flexible slider-crank mechanism, the coordinate partitioning scheme and the Udwadia-Kalaba formulation are herein compared. The flexibility of the coupler has been modelled by means of a single Timoshenko beam element. The present analytical treatment can be viewed as an extension of the model discussed by Shabana in his textbook.     

直线振动筛出料梁的模态分析

以一台大型直线振动筛出料梁为研究对象,应用Pro/E软件建立了出料梁的三维模型,并利用ANSYS/Workbench软件建立出料梁的有限元模型,完成了出料梁的模态分析,分析结果可为优化振动筛结构设计提供依据。     

ANSYS非线性有限元软件在桥梁结构分析中的应用

有限无法是分析复杂工程结构的一种非常有效的数值方法．本文通过叙述采用ANSYS进行钢箱梁结构分析的实施步骤，介绍了使用ANSYS非线性有限元软件进行桥梁结构分析的方法．     

复合悬臂曲梁力学性能的研究

用有限元方法对复合悬臂曲梁进行了数值分析,求得了复合悬臂曲梁的正应力和切应力。设计并制作了复合悬臂曲梁的实验模型并进行了应力测试,将两者结果与解析解进行比较,进一步验证了复合曲梁的理论公式的正确性,此举也为高校有关复合曲梁的开放性实验提供了一些参考。     

烟叶高层醇化库楼盖体系的优化

烟草片烟醇化库采用高层库房是对高效率使用土地的一种响应。通过对普通井字梁楼盖与蜂巢芯密肋楼盖在设计、施工、后期使用维护及经济性等多方面的对比,阐述在烟叶醇化高层库中采用蜂巢芯密肋楼盖结构体系的综合优势,在烟草行业库房工程中具有很好的推广价值。     

Simulation experiments on counter beam lighting in highway tunnel

Counter beam lighting was introduced as well as transverse symmetrical lighting and longitudinal symmetrical lighting. Simulation experiments were carried out by using DIAlux lighting software for the above three lighting methods. The results show that counter beam lighting is more reasonable to be adopted in the tunnel entrance zone because its threshold increment of disability glare is greater. Counter beam lighting can improve the background luminance of the obstacles and lighting efficiency compared with transverse symmetrical lighting and longitudinal symmetrical lighting. Therefore, tunnel lighting energy-saving can be achieved by reducing the road luminance demands and luminaries power. Longitudinal symmetrical lighting is conducive to the large luminaries spacing in the tunnel internal zone; so power consumption can be reduced by decreasing the number of luminaries used. Tunnel walls are unsuitable to pave with smooth or bright material. Installation height of the luminaries has less effect on counter beam lighting.