排序方式: 共有51条查询结果,搜索用时 15 毫秒
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目的:观察急性有氧运动对肥胖男青年肱动脉内径的影响.方法:以14名肥胖男生为研究对象,测定其运动前(0h时间点)肱动脉内径,然后立刻进行持续45min的急性跑台运动,在运动结束后的15min和75min(即1h和2h时间点)时,对其肱动脉内径进行重复测定.结果:0h、1h和2h3个时间点的肱动脉内径分别是3.91±0.07mm,4.07±0.07mm和3.95±0.06mm,1h时肱动脉内径明显高于0h(P<0.05),但2h时与0h和1h无明显差别.结论:急性有氧运动使肥胖男青年的肱动脉内径一过性增大,但此效应会在运动结束后较快地消失. 相似文献
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李东升 《数理天地(初中版)》2008,(6):43-44
有一支温度计,它的刻度是均匀的.可是,用此温度计实测温度时,读数并不准确.这是什么原因呢?一般来说,一是由于温度计零刻度线的位 相似文献
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1实验装置图(图1)2仪器制作①取内径7mm左右的玻璃导管,弯制成“W”形。②用小纸槽分别从“W”形管的两端开口处加入少许CuO粉末和无水CuSO4粉末。③靠CuO端连接干燥的H2,靠无水CuSO4端连接尖嘴铝管。 相似文献
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针对滑动轴承中的铜基合金轴瓦加工工序较多,加工较麻烦的情况,文章阐述了如何减少滑动轴承中的铜基合金轴瓦加工工序的问题,以达到简化其生产过程的目的。 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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