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螺旋椭圆扁管强化传热研究 被引量:10
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作者 黄德斌 邓先和 +1 位作者 王扬君 黄素逸 《石油化工设备》 CAS 2003年第3期1-4,共4页
在设计的油 水换热实验台上,对4种不同结构的螺旋椭圆扁管和2种尺寸的直椭圆管套管式换热器进行了实验研究,归纳出了管内换热及阻力公式,对4种螺旋椭圆扁管的传热和阻力性能进行了比较分析,证明螺旋椭圆扁管是1种很有应用前景的换热元件... 在设计的油 水换热实验台上,对4种不同结构的螺旋椭圆扁管和2种尺寸的直椭圆管套管式换热器进行了实验研究,归纳出了管内换热及阻力公式,对4种螺旋椭圆扁管的传热和阻力性能进行了比较分析,证明螺旋椭圆扁管是1种很有应用前景的换热元件,特别是对高Pr(如各种油品)在低Re运行时层流或过渡流效果良好。 展开更多
关键词 换热器 螺旋椭圆扁管 强化传热 经验方程式
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木材导温系数模型的研究 被引量:4
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作者 钟云志 钟义山 《西北林学院学报》 CSCD 北大核心 2003年第2期84-86,共3页
研究了一定条件下木材导温系数与温度、含水率、密度及声速的相关关系,分别导出了弦向和径向导温系数的经验回归方程式。所得理论值和实际值平均相对误差不超过0.3%,相对误差绝对值平均不超过4.8%。
关键词 木材 导温系数 经验回归方程式 热学性质 模型
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冶金分析中硅钼蓝光度法的研究与应用 被引量:3
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作者 马雷 刘雅贞 张爱民 《冶金分析》 CAS CSCD 北大核心 2004年第z1期297-299,共3页
总结冶金分析中硅钼蓝光度法测硅的重点和难点及操作经验,论述和优化了硅钼蓝光度法的测定条件.
关键词 冶金分析 硅钼蓝光度法 经验方程式
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Selection of the Proper Hammer in Pile Driving and Estimation of the Total Driving Time
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作者 Alireza Afshani Ali Fakher Massoud Palassi 《Journal of Civil Engineering and Architecture》 2012年第12期1663-1671,共9页
There are various methods for analyzing pile driving process such as dynamic formulas, wave equation analyses and dynamic measurements. The programs of the two latter methods are relatively expensive to purchase and a... There are various methods for analyzing pile driving process such as dynamic formulas, wave equation analyses and dynamic measurements. The programs of the two latter methods are relatively expensive to purchase and also require trained engineers to interpret the data it collects. Meanwhile, the use of the site specific empirical formulas based on the real cases of pile driving and output analyses of the wave equation analysis programs can be beneficial. In the current study, pile driving data from three sites in the south of Iran were collected. Using the data of these cases and one-dimensional wave equation analysis program GRLWEAP, couple of experimental formulas which determine the proper range of hammer's ID for driving a pile, are proposed. Finally, due to the importance of the time in marine projects, another experimental formula is also proposed for estimation of the total driving time. 展开更多
关键词 Pile driving hammer selection total driving time GRLWEAP driveability analysis.
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Three Semi-empirical Analytic Expressions for the Radial Distribution Function of Hard Spheres
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作者 SUNJiu-Xun CAILing-Gang +1 位作者 WUQiang JINGFu-Qian 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第3期400-404,共5页
Three simple analytic expressions satisfying the limitation condition at low densities for the radial distribution function of hard spheres are developed in terms of a polynomial expansion of nonlinear base functions ... Three simple analytic expressions satisfying the limitation condition at low densities for the radial distribution function of hard spheres are developed in terms of a polynomial expansion of nonlinear base functions and the Carnahan-Starling equation of state. The simplicity and precision for these expressions are superior to the well-known Percus Yevick expression. The coefficients contained in these expressions have been determined by fitting the Monte Carlo data for the first coordination shell, and by fitting both the Monte Carlo data and the numerical results of PercusYevick expression for the second coordination shell. One of the expressions has been applied to develop an analytic equation of state for the square-well fluid, and the numerical results are in good agreement with the computer simulation data. 展开更多
关键词 radial distribution function hard spheres equation of state square-well fluids
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