第9届世界健美操锦标赛6人操决赛托举动作分析

采用文献资料法、录像观察法和对比分析法，对2006年第9届世界健美操锦标赛6人操决赛前8名队伍的托举动作进行分析，找出各队伍托举动作的相同与独特之处，以期对从事竞技健美操6人操托举动作的工作者提供参考。     

遥控方便桌的设计

本遥控方便桌属机械电子类,病人不能下床搬桌,通过遥控装置方便灵活移动与升降桌子。该项目已获实用新型专利证书,专利号：ZL201220436108.1。①该桌配备红外线遥控器控制功能,感应器反应快速。病人操作简单,使用方便。②桌面电动升降,安全可靠。根据病人医治、看书和上网所需,手动或自动遥控桌子进退,左右转及桌面升降。③利用单片机根据程序使桌子有自动行进,病人只按遥控器中一个按键,桌子即自动进退转弯和停止。④轻巧牢固,节约空间,方便携带,可叠放。桌子整体重约5kg。     

Relationship between shoulder roll and hand propulsion in the front crawl stroke

This study re-evaluated the magnitude of hand propulsion (HP) in the pull and push phases of the front crawl stroke and investigated the association between the angular velocity of shoulder roll (ω_SR) and hand propulsive lift (HP_L). ω_SR was computed in the plane normal to a forward direction for 16 skilled swimmers performing the front crawl stroke at a maximal sprinting pace. HP, hand propulsive drag (HP_D) and HP_L were determined by a dynamic pressure approach. HP and HP_D in the pull phase were greater than in the push phase (P < 0.05) while HP_L in the pull phase was similar to that in the push phase. Eleven swimmers out of the 16 swimmers had a significant within-swimmers correlation between ω_SR and HP_L in the push phase (P < 0.05). That is, HP_L increased in the push phase as the ω_SR of rolling back to the neutral position became faster. A swimmer should use more drag for hand propulsion in the pull phase and propulsion from drag and lift equally in the push phase. Based on the relationship between ω_SR and HP_L in the push phase, a possible stroke technique to enhance HP_L using ω_SR is discussed.     

用于确定疲劳载荷谱的共轴直升机气动力参数数值模拟

本文探索了共轴直升机气动力参数估算技术,用以确定其疲劳载荷谱。首先给出了气动力计算的主控方程和数值方法,然后,分别建立了共轴直升机机身与旋翼的三维层流和湍流流场模拟的物理模型和计算网格模型,采用计算流体力学(CFD)方法,进行了共轴直升机机身与旋翼的层流和湍流流场数值模拟,估算了其气动力参数曲线,并对计算结果进行了分析对比,以检验建模技术的有效性,分析结果表明:该项技术实用可行,能得到一些与工程实际吻合的现象和结论。     

低保对象脱贫探讨

在我国，低保对象还将长期大量地存在，政府应通过不断完善城市居民最低生活保障制度，加大就业帮扶力度，积极发展医疗、教育、住房救助项目，鼓励社会互助和社会慈善捐助等措施帮助低保人群脱贫。     

基于汽车溺水过程分析的车窗机械结构优化

汽车驶入水中导致司乘人员伤亡的事故近年来逐渐增多,尤其是城市中地势低洼排水不畅的地段在大雨后容易积存大量雨水,司机在不知水深的情况下冒然驶入,导致车体没入水中,车门车窗无法打开造成惨剧.针对这一问题,以北京现代伊兰特汽车左前车门车窗升降机构为例,通过计算进行结构模拟和优化,从而减少人员伤亡.结果表明,经过对伊兰特左前车门车窗升降机构改进后,司乘人员能够达到成功逃生的目的,事故伤亡率大大降低.     

子群有正规补的一个特征标条件

文章主要包括两个结果，一个是关于有限交换群的子群与同态像之间的联系．另一个是关于子群有正规补的一个特征标刻划。     

基于MSP430单片机的太阳能充电控制器设计

设计制作了一个太阳能充电控制器,可实现75 W太阳能电池板对蓄电池的可靠充电。主要采用Cuk电路和光耦电压反馈,并利用TL494实现PWM控制,LM393加互补功放实现驱动。通过MSP430单片机和1602液晶进行电压采样和显示。经实验论证,本方案基本完成了设计预期。     

二维翼型节能减阻效果的研究

就现阶段国内外研究成果分析,肋片具有减小摩擦阻力及增加流动扰动等特点。平板上采用肋片减阻的效果及肋片参数对减阻的影响已相对清晰,而二维翼型上采用加装肋片后减阻效果如何变化还未可知。文章选取二维翼型S825并使用计算流体力学软件Fluent进行气动性能计算及性能分析,初步发现翼型的表面减阻效果的影响规律,得到升、阻力系数随攻角的变化关系。并用该软件计算带肋片的二维翼型的气动性能,与无肋片的翼型气动性能进行对比分析。结果显示：肋片结构在翼型表面可以产生一定的减阻效果;总阻力的计算公式为压差阻力与粘性阻力之和。由于二维翼型上加装了肋片,改变了压差阻力和粘性阻力,继而改变了总阻力的数值,产生了很好的减阻效果。     

Comparison of split double and triple twists in pair figure skating

In this study, we compared the kinematic variables of the split triple twist with those of the split double twist to help coaches and scientists understand these landmark pair skating skills. High-speed video was taken during the pair short and free programmes at the 2002 Salt Lake City Winter Olympics and the 2003 International Skating Union Grand Prix Finals. Three-dimensional analyses of 14 split double twists and 15 split triple twists from eleven pairs were completed. In spite of considerable variability in the performance variables among the pairs, the main difference between the split double twists and split triple twists was an increase in rotational rate. While eight of the eleven pairs relied primarily on an increased rotational rate to complete the split triple twist, three pairs employed a combined strategy of increased rotational rate and increased flight time due predominantly to delayed or lower catches. These results were similar to observations of jumps in singles skating for which the extra rotation is typically due to an increase in rotational velocity; increases in flight time come primarily from delayed landings as opposed to additional height during flight. Combining an increase in flight time and rotational rate may be a good strategy for completing the split triple twist in pair skating.