Low frequency oscillatory flow in a rotating curved pipe

INTRODUCTIONThemotionoftheflowinarotatingcurvedpipeisafundamentalproblem ,whosesolutionhaspotentialapplicationsingasturbines ,elec tricgenerators ,electricmotorsandsomeequip mentsusedinseparationprocesses.Itisimpor tanttoknowtheflowstructurecharacteristic…     

用粒子数表象处理非简并定态微扰问题

运用粒子数表象,解决了微观粒子受到外界微扰作用时能量的二级修正和波函数的一级修正,避免了繁杂的运算.     

一类小参数Sturm-Liouvil1e特征问题的摄动解

本文在某种条件下，得到了一类小参数S－L特征问题的摄动解，推广了文[1,2]的相应结果。     

光纤孤立波传输中的高阶色散研究

分析了影响高阶色散的因素,利用微扰法求解无损耗高阶色散传输方程,得到了高阶色散对光纤孤立波传输影响的几个结论。这些结论对零散孤立波传输系统的优化设计是很有用的。     

均匀磁场中三维各向同性谐振子n=4能级简并度的解除

在考虑均匀磁场中三维各向同性谐振子哈密顿量中B2项影响的情况下,计算了均匀磁场中三维谐振子n=4能级的微扰矩阵元和一级能量修正值,并讨论了其能级简并度的解除.     

扰动微分系统的一致Lipschitz稳定性

本文给出了两类扰动微分系统的零解是一致Ｌｉｐｓｃｈｉｔｚ稳定的充分条件。     

Low frequency oscillatory flow in a rotating curved pipe

The low frequency oscillatory flow in a rotating curved pipe was studied by using the method of biparameter perturbation. Perturbation solutions up to the second order were obtained and the effects of rotation on the low frequency oscillatory flow were examined in detail. The results indicated that there exists evident difference between the low frequency oscillatory flow in a rotating curved pipe and in a curved pipe without rotation. During a period, four secondary vortexes may exist on the circular cross-section and the distribution of axial velocity and wall shear stress are related to the ratio of the Coriolis force to centrifugal force and the axial pressure gradient. Project (No: 10272096) supported by the National Natural Science Fundation of China     

Perturbation spectrum method for seismic analysis of non-classically damped systems

Fundamental principles from structural dynamics, random theory and perturbation methods are adopted to develop a new response spectrum combination rule for the seismic analysis of non-classically damped systems, such as structure-damper systems. The approach, which is named the perturbation spectrum method, can provide a more accurate evaluation of a non-classically damped system＇s mean peak response in terms of the ground response spectrum. To account for the effect of non-classical damping, all elements are included in the proposed method for seismic analysis of structure, which is usually approximated by ignoring the off-diagonal elements of the modal damping matrix. Moreover, as has been adopted in the traditional Complete Quadratic Combination （CQC） method, the white noise model is also used to simplify the expressions of perturbation correlation coefficients. Finally, numerical work is performed to examine the accuracy of the proposed method by comparing the approximate results with exact ones and to demonstrate the importance of the neglected off-diagonal elements of the modal damping matrix. In the examined cases, the proposed method shows good agreement with direct time-history integration. Also, the perturbation spectrum method leads to a more efficient and economical calculation by avoiding the integral and complex operation.     

六艺之旨,散在 《论语》———马一浮 《论语大义》 概述简

六艺（亦称六经）是中国文化的源头活水。作为记载孔子及其弟子言行的《论语》切实表达了六艺的旨趣,对中国传统文化与价值观的奠基起到了纲领性的作用。孔子好古敏求,有着深切的文化与历史传承意识,可以说六艺是其理论思想的来源,而他在发挥六经大义的过程中,将其提升到了“仁”的高度,为六经树立了坚实的心性本体基础。而六艺之为教,其中自有本末、先后之次第,马先生在对《论语》旨趣的阐释中,不仅本儒家经典以立言,又融入了佛教之思想,凸显了中国传统学术之一贯性与包容性。     

再谈单摆的运动

本文讨论单摆的非线性行为,并探讨混沌现象产生的机理。