高速剪切轴向间隙的研究     

李耀辉  许春龙 《苏州市职业大学学报》2003,14(1):47-49

本针对剪切下料问题中存在的不足，从裂纹扩展的角度出发，结合断裂力学及塑性力学关于裂纹技术的相关理论，对剪切过程中影响断面质量的一个重要参数一轴向间隙进行分析，得出了高速剪切下合理轴向间隙的表这式。  相似文献   

2002-2003年度中国男子篮球甲级联赛"三人制"裁判员临场情况的调查分析   总被引：1，自引：0，他引：1  

石振国  陈家起  丁庆建  孙传宁 《中国体育科技》2004,40(6):35-37

通过设计调查表对2002-2003年度中国男子篮球甲级联赛中三人制裁判员的临场情 况进行了统计分析。结果表明,裁判员在合理分配体能、判罚尺度与角度、三人协同配合、心理调 节等方面还存在着不尽合理的地方。建议,裁判员应加强三人制裁判法和规则的钻研学习,加强 体能锻炼,加强临场心理素质的培养,不断积累比赛临场经验,以促进和维护CBA的健康发展。  相似文献   

核酸四碱基体及四螺旋模型的理论构建     

邵丹  谢君  刘世熙  刘次全 《玉溪师范学院学报》2002,18(3):64-71

核酸的结构具有多态性 ,核酸的功能取决于其结构 .了解核酸不同结构的特征有利于对其功能的充分认识 .本文对核酸四碱基体及其形成的四链结构模型进行了理论研究 .这些工作有助于从理论上进一步研究核酸四螺旋结构 ,对相关的实验研究也将起到有益参考作用 .  相似文献   

对第17届世界杯足球赛射门进球的统计分析   总被引：38，自引：0，他引：38  

邹秋华  胡洪泉 《广州体育学院学报》2003,23(1):51-53,56

运用录像观察统计法、文献资料法、对比分析法和归纳分析法，对17届世界杯足球赛64场比赛中的161个进球进行分类统计分材，揭示了高水平足球赛进球的规律和特征，明晰了当今技战术发展的趋势、潮流与动向，探讨提高射门效果的方法和手段。  相似文献   

划水板流体动力特征的风洞实验研究     

狄建  吴钟权  张彬乾  王宗栋  叶保增  周瑞兴 《体育科学》1991,(4)

本文介绍了自行研制的三种划水板和国外两种划水板及其在风洞内进行的测力实验,以了解分析其不同的流体动力特征;对板面开孔与无孔吹风测力、板面有或无稳流板条及板条分布的测试结果,为新型划水板的设计提供了理论依据。研究发现,螺旋曲面扭转结构的自制板对运动员手掌最佳对水倾斜角有诱导修正作用,能帮助运动员建立良好的技术,提高“水感”,获得理想的划水效果。实验结果表明以上观点是可以肯定的。  相似文献   

Understanding key performance indicators for breast support: An analysis of breast support effects on biomechanical,physiological and subjective measures during running     

Debbie Risius  Alexandra Milligan  Jason Berns  Nicola Brown 《Journal of sports sciences》2017,35(9):842-851

To assess the effectiveness of breast support previous studies monitored breast kinematics and kinetics, subjective feedback, muscle activity (EMG), ground reaction forces (GRFs) and physiological measures in isolation. Comparing these variables within one study will establish the key performance variables that distinguish between breast supports during activities such as running. This study investigates the effects of changes in breast support on biomechanical, physiological and subjective measures during running. Ten females (34D) ran for 10 min in high and low breast supports, and for 2 min bare breasted (2.8 m·s^?1). Breast and body kinematics, EMG, expired air and heart rate were recorded. GRFs were recorded during 10 m overground runs (2.8 m·s^?1) and subjective feedback obtained after each condition. Of the 62 variables measured, 22 kinematic and subjective variables were influenced by changes in breast support. Willingness to exercise, time lag and superio-inferior breast velocity were most affected. GRFs, EMG and physiological variables were unaffected by breast support changes during running. Breast displacement reduction, although previously advocated, was not the most sensitive variable to breast support changes during running. Instead breast support products should be assessed using a battery of performance indicators, including the key kinematic and subjective variables identified here.  相似文献   

基于STAR-CCM+的汽车挡风玻璃除霜性能提升的仿真分析与研究     

胡忠文 《苏州市职业大学学报》2021,(1)

采用计算流体动力学的方法,利用STAR-CCM+软件对某一车型挡风玻璃除霜性能进行数值模拟分析。通过对出风口格栅进行调整,改变了暖风气流与挡风玻璃之间碰撞角的大小与碰撞点的位置,优化了挡风玻璃表面暖风气流的分布,提升了除霜性能,为汽车除霜风道的设计和改善车辆除霜性能提供了参考。  相似文献   

Science Letters:Discovery of ultrahigh-T spinel-garnet granulite with pure CO_2 fluid inclusions from the Altay orogenic belt, NW China     

厉子龙  陈汉林  杨树锋  SANTOSH M. 《Journal of Zhejiang University. Science. B》2004,(10)

We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel, and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the or-thopyroxenes have high XMg and A12O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2 densities of the order of 0.86-0.88 g/cm3. Based on prelim  相似文献   

自制力学框架在物理教学中的应用     

胡帅 《中国教育技术装备》2006,(7):20-21

介绍自制的力学框架，并举例说明其在物理教学中的具体应用。  相似文献   

工程力学建模     

杨冠声 《天津职业院校联合学报》2007,9(6):12-15

传统的工程力学教学,直接就力学模型讲授理论的应用,缺乏从工程问题中抽象出力学模型的环节,与应用脱节,不利于学生的技能培养。在教学实际中,可以根据"可靠性"、"经济性"原则,将工程力学建模分解为"主体的处理"、"力的处理"、"联结的处理"三个基本过程。  相似文献