两方国礼歙砚

黄山市砚雕家郑寒先生雕刻的一方黄山胜迹印痕砚，被选作李鹏总理赠送给日本明仁天皇的国礼；另一方歙砚中国龙砚，被选中作为胡锦涛主席赠送给法国总统希拉克的国礼，创造出“两件国礼出自同一位砚雕家之手”的奇迹。     

太极拳运动对2型糖尿病患者血脂成分及胰岛素抵抗的影响

为了进一步揭示太极拳锻炼对2型糖尿病影响的机制,文章以16名中老年肥胖者为对象,观察了太极拳锻炼前后血脂成分和胰岛素敏感性等指标的变化,经过20周太极拳运动后,患者血清TG、LDL-C、GHbA1c、FPG等成分明显降低,HDL-C水平则明显升高(p<0.01),ISI明显下降,说明太极拳运动可以改善2型糖尿病患者血脂成分,有助于胰岛素抵抗功能的改善。     

我国民族传统体育的人文价值

民族传统体育是我国民族传统文化的宝贵财富,蕴藏着深厚丰富的民族传统文化内涵和人文价值。历史证明,我国民族传统体育在人文精神、传统教育、道德修养和审美情趣的培养等方面有着重要的意义和价值,对提高我国各民族的健康水平、人文素质,构建和谐社会将发挥重要的作用。     

以Chirp信号激励的虚拟频谱分析仪实现

介绍了一种采用Chirp信号作为激励信号的虚拟频谱分析仪的设计原理,并利用图形化编程工具LabVIEW 6.1实现了此种虚拟频谱分析.实验测试结果表明采用LabVIEW6.1所设计的以Chirp作为激励信号的虚拟频谱分析仪具有较好的测量效果,可比传统频谱分析仪更快捷地测量出系统的幅频特性和相频特性.     

Describing the plastic deformation of aluminium softball bats

Hollow aluminium bats were introduced over 30 years ago to provide improved durability over wooden bats. Since their introduction, however, interest in hollow bats has focused almost exclusively around their hitting performance. The aim of this study was to take advantage of the progress that has been made in predicting bat performance using finite elements and apply it to describe bat durability. Accordingly, the plastic deformation from a ball impact of a single-wall aluminum bat was numerically modelled. The bat deformation from the finite-element analysis was then compared with experiment using a high-speed bat test machine. The ball was modelled as an isotropic, homogeneous, viscoelastic sphere. The viscoelastic parameters of the ball model were found from instrumented, high-speed, rigid-wall ball impacts. The rigid-wall ball impacts were modelled numerically and showed good agreement with the experimentally obtained response. The strain response of the combined bat-ball model was verified with a strain-gauged bat at intermediate ball impact speeds in the elastic range. The strain response of the bat-ball model exhibited positive correlation with the experimental measurements. High-speed bat-ball impacts were performed experimentally and simulated numerically at increasing impact speeds which induced correspondingly increased dent sizes in the bat. The plastic deformation from the numerical model found good agreement with experiment provided the aluminium work hardening and strain rate effects were appropriately described. The inclusion of strain rate effects was shown to have a significant effect on the bat deformations produced in the finite-element simulations. They also helped explain the existence of high bat stresses found in many performance models.