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排序方式: 共有6998条查询结果,搜索用时 8 毫秒
991.
A study of the stabifity of plane Poiseuille flow at higher Reynolds number is made. Within a "triple-deck" structural framework, the qualitative behaviour of the eigenvalue of Orr-Sommerfeld equation is analytically obtained. The corresponding eigenfunction is formulated approximately. 相似文献
992.
朱允民 《应用数学和力学(英文版)》1986,7(5):471-479
A recursive algorithm with randomly varying truncation for adaptive Bram-Formers is proposed. Simple conditions are obtained to guarantee for this algorithm the global convergence almost everywhere. 相似文献
993.
戴世强 《应用数学和力学(英文版)》1985,6(5):409-415
In this paper, an asymptotic method is presented for the analysis of a class of strongly nonlinear autonomous oscillators. The equations governing the amplitude and phase factor are obtained, and the amplitude and stability of the corresponding limit cycles are determined. 相似文献
994.
In this paper we derive the approximate theory on the straight cantilever beam of a same circular cross section including transverse shear deformation, using the general variational principle with two class variates, and we present the expression with two class variates containing two general displacement, of general complementary energy, corresponding with the theory. 相似文献
995.
Simulation of Nanoparticle Production in Premixed Aerosol Flow Reactors by Interfacing Fluid Mechanics and Particle Dynamics 总被引:3,自引:0,他引:3
The interaction of fluid mechanics and particle dynamics at the very early stages of flame synthesis largely affects the characteristics of the product powder. Detailed simulations provide a better understanding of these processes, which take place in a few milliseconds, and offer the possibility to influence the product characteristics by intelligent selection of the process parameters. The present paper reports on the simulation of titania powder formation by TiCl4 oxidation in an aerosol flow reactor. A commercially available fluid mechanics code is used for the detailed calculation of the fluid flow and the chemical reaction at non-isothermal conditions. This code is then interfaced with a model for aggregate particle dynamics neglecting the spread of the particle size distribution. The simulation shows the onset of the particle formation in the reactor and calculates the dynamic evolution of the aggregate particle size, number of primary particles per aggregate and the specific surface area throughout the reactor. The presented, newly developed calculation technique allows for the first time the simulation of particle formation processes under the authentic, complex conditions as found in actual aerosol reactors. 相似文献
996.
FTIR spectroscopy was used to study the hydrogen bonding of stearic acid with ethanol, dimethyl sulfoxide (DMSO),and acetonitrile in supercritical CO_2 at 318.15 K, and 12.5 and 16.5 MPa. The concentrations of the cosolvents range from 0—0.6 mol·L~(-1). The area percentage of absorption bands for hydrogen-bonded and nonhydrogen-bonded species was obtained from the IR spectra. The acid and the cosolvents can form hydrogen bond even when their concentrations are very low. At fixed solute concentration, the extent of hydrogenbonding increases with cosolvent concentration. At higher ethanol concentrations, it seems that one stearic acid molecule can hydrogen bond with more than one ethanol molecules simultaneously. It is seen that the strength of the hydrogen bond formed by the acid and the cosolvents is in the order: DMSO>ethanol>acetonitrile. 相似文献
997.
998.
含ER流体板结构的振动特性研究 总被引:8,自引:0,他引:8
本文制作了含电流变体夹层梁和模拟飞机蒙皮结构的含电流变体加筋层合板,采用响应幅频法,测试了在不同电场强度梁和层合加筋板结构各阶固有频率和振幅的变化;并着重测试了加筋层合板结构在改变板材料、电流变体作用面积等条件时各阶频响特性的变化。实验结果表明,随着电场强度的增加,夹层梁的频响特性有很大变化;而层合板的固有频率变化不大,但振幅却有显著变化,其中铝-层合加筋板的频响幅值的变化率达到50.1%。 相似文献
999.
1000.
We extend the analysis of orientational first-order phase transitions in anisotropic molecular fluids at high spatial dimensionality to hard-disk fluids, and then to mixture of hard disks and hard spheres. The effect of hard-sphere admixture depends sensitively on the relative sizes of the two geometrical objects, and large spheres completely quench the disk transition. An introductory study is made of spatially ordered states. 相似文献