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81.
José Teixeira Freire 《中国颗粒学报》2008,6(2)
Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures: a reference (monoparticles), a binary mixture, two ternary mixtures with flat and Gaussian distributions respectively. The mixtures were selected for particle diameters (dp) ranging from 1.09 to 4.98 mm and particle diameter ratios (dpL/dps) ranging from 1.98 to 4.0. Experimental data show that pressure fluctuation signals of the bed, as indicated by changes in their standard deviations, provide suitable information to identify the range of operational conditions for stable spouting. However, the analysis of skewness of curves of pressure fluctuation as a function of air velocity appears not sufficient to identify a particular flow regime. For glycerol in the spouting regime, the standard deviation is noted to increase with increasing glycerol concentration due to the growth of interparticle forces. The implications of these research findings on the drying of suspensions in conical spouted beds using glass bead mixtures are also discussed. 相似文献
82.
A modified U-tube conical bubble sonoluminescence device is used to
study the conical bubble photoluminescence. The spectra of conical
bubble sonoluminescence at different concentrations of rhodamine 6G
(Rh6G) solution in 1,2-propanediol have been measured. Results show
that the sonoluminescence from the conical bubbles can directly
excite Rh6G, which in turn can fluoresce. The light emission of this
kind is referred to as conical bubble photoluminescence. The maximum
of fluorescence spectral line intensity in the conical bubble
photoluminescence has a red shift in relative to that of the
standard photo-excited fluorescence, which is due to the higher
self-absorption of Rh6G, and the spectral line of conical bubble
photoluminescence is broadened in width compared with that of
photo-excited fluorescence. 相似文献
83.
在空间Ωn-span{cos t,sint,tCOSt,tsin t, 1,t,t^2,…,t^n-4。}(n≥4)中构造拟Bernstein基,并用其来构造Q。中的曲线,称为拟B6zier曲线,该类曲线具有很多与B6zier曲线类似的性质,利用这些性质可以对曲线进行升阶,升阶得到的控制多边形序列收敛到曲线.拟B6zier曲线这类曲线可以精确表示圆锥螺线,圆的渐开线等超越曲线. 相似文献
84.
The problem of axisymmetric nonlinear vibration for shallow thin spherical and conical shells when temperature and strain fields are coupled is studied. Based on the large deflection theories of yon Ktirrntin and the theory of thermoelusticity, the whole governing equations and their simplified type are derived. The time-spatial variables are separated by Galerkin ‘ s technique, thus reducing the governing equations to a system of time-dependent nonlinear ordinary differential equation. By means of regular perturbation method and multiple-scales method, the first-order approximate analytical solution for characteristic relation of frequency vs amplitude parameters along with the decay rate of amplitude are obtained, and the effects of different geometric parameters and coupling factors us well us boundary conditions on thermoelustically coupled nonlinear vibration behaviors are discussed. 相似文献
85.
86.
87.
THE CONSTRUCTION OF WAVELET-BASED TRUNCATED CONICAL SHELL ELEMENT USING B-SPLINE WAVELET ON THE INTERVAL 总被引:4,自引:0,他引:4
Xiang Jiawei He Zhengjia Chen Xuefeng 《Acta Mechanica Solida Sinica》2006,19(4):316-326
Based on B-spline wavelet on the interval (BSWI), two classes of truncated conicalshell elements were constructed to solve axisymmetric problems, i.e. BSWI thin truncated conicalshell element and BSWI moderately thick truncated conical shell element with independent slope-deformation interpolation. In the construction of wavelet-based element, instead of traditionalpolynomial interpolation, the scaling functions of BSWI were employed to form the shape functionsthrough the constructed elemental transformation matrix,and then construct BSWI element viathe variational principle. Unlike the process of direct wavelets adding in the wavelet Galerkinmethod, the elemental displacement field represented by the coefficients of wavelets expansionwas transformed into edges and internal modes via the constructed transformation matrix. BSWIelement combines the accuracy of B-spline function approximation and various wavelet-basedelements for structural analysis. Some static and dynamic numerical examples of conical shellswere studied to demonstrate the present element with higher efficiency and precision than thetraditional element. 相似文献
88.
离散元方法广泛应用于海冰,特别是碎冰区的动力过程及其对海洋结构作用过程的数值模拟。为构造碎冰区中的冰块几何特性,基于二维Voronoi图方法对计算域进行随机切割以生成碎冰区中冰块的几何形态,并采用球体单元对每个碎冰块单元进行填充,从而确定碎冰区的初始分布场。在采用Voronoi图进行碎冰区构造时,可对冰块尺寸、几何形态和密集度等海冰参数进行设定。为确定冰块的不同几何规则度,综合采用排斥法和扰动法以定量地控制碎冰块几何形态从完全随机分布到规则分布的连续变换。为分析不同几何规则度下碎冰块的几何特性概率分布规律,对计算域内冰块的面积和边数等参数进行统计分析,从而可更合理地参数化控制初始冰场中碎冰块的几何特性。在此基础上,本文基于粘接-破碎的球体离散元方法对不同冰况下锥体结构的冰荷载进行了数值计算,讨论分析了碎冰区的海冰密集度、冰块面积和几何规则度对冰载荷的影响。 相似文献
89.
通过对麦克斯韦方程格林函数的计算 ,我们得到它的求解公式 ,然后解释为什么一束光线射到冰洲石表面上会产生两束折射光线 ,并描述了折射光线的路径 相似文献
90.
Charitos Charalambos Papadoperakis Ioannis 《Annals of Global Analysis and Geometry》2003,23(4):323-357
The geometry of compact hyperbolic surfaces with conical singularities isinvestigated. The Teichmüller space of a hyperbolic pair of pants with asingle singularity is studied. A finite number of real parameters whichdetermine the geometry of a hyperbolic torus of genus two with a singlesingularity, is given. 相似文献