Finite particle method for kinematically indeterminate bar assemblies

This study presents a structural analysis algorithm called the finite particle method （FPM） for kinematically indeterminate bar assemblies. Different from the traditional analysis method, FPM is based on the combination of the vector mechanics and numerical calculations. It models the analyzed domain composed of finite particles. Newton＇s second law is adopted to describe the motions of all particles. A convected material flame and explicit time integration for the solution procedure is also adopted in this method. By using the FPM, there is no need to solve any nonlinear equations, to calculate the stiffness matrix or equilibrium matrix, which is very helpful in the analysis of kinematically indeterminate structures. The basic formulations for the space bar are derived, following its solution procedures for bar assemblies. Three numerical examples are analyzed using the FPM. Results obtained from both the straight pretension cable and the suspension cable assembly show that the FPM can produce a more accurate analysis result. The motion simulation of the four-bar space assembly demonstrates the capability of this method in the analysis ofkinematically indeterminate structures.     

Optimal design of Stewart platforms based on expanding the control bandwidth while considering the hydraulic system design

We proposed an optimal design method to expand the bandwidth for the control of large hydraulic Stewart platform. The method is based on generalized natural frequency and takes hydraulic oil into consideration. A Lagrangian formulation which considers the whole leg inertia is presented to obtain the accurate equivalent mass matrix. Using the model, the effect of leg inertia and the influence of design parameters on the generalized natural frequency are investigated. Finally, numerical examples are presented to validate and confirm the efficiency of the mathematical model. The results show that the leg inertia, especially the piston part plays an important role in the dynamics. The optimum diameter ratio of the base to the moving platform is between 2 and 3, and the optimum joint angle ratio of the base to the moving platform is about 1. The smaller joint angles and a longer leg stroke are favorable for raising system frequencies. The system oil should be preprocessed for large platforms with a requirement for good dynamic performance.     

关于低值易耗品摊销等问题的探讨

根据会计学课程教学实践，就高等专科学校会计学教科书中有关低易耗品摊销等问题进行了探讨，提出了一些建设性看法。     

论"侠"对平民的影响

侠文化早已深入人心,作为一个重要的文化现象,它已经对平民,进而对社会产生了重要的影响, 本文从平民的慕侠思想,群体的特征,侠与主流社会的关系,现代传媒对侠文化的推广,平民眼中侠形象的变异等多方面对"侠"对平民的进而对社会的影响作了剖析.     

广义导算子的左、右本性逆(英文)

本文给出了广义导算子左、右本性可逆的一系列等价条件,其主要结果是定理4和5。     

反应物转动激发对反应O(~3P)+HCl→OH+Cl反应的影响

基于Ramachandran B等人制作的3 A′′势能面[Ramachandran B et al 2003J.Chem.Phys.1199590],运用准经典轨线方法,计算了反应物不同振动激发态时,反应O(3P)+HCl(υ=0,1,2,j=0)→OH+Cl的P(θr),P(φr)与极化微分反应截面(2π/σ)(dσ00/dωt)、(2π/σ)(dσ22+/dωt).结果表明,反应物HCl振动激发对反应的k-j′两矢量相关和k-k′-j′三矢量相关分布都产生了较大影响.     

Schur不等式的一个改进

本文给出了Schur不等式的一个改进,该结论进一步优化完善了文献[1,4]的相应结果.     

基于广义论证的三段论与“五支论式”比较研究

广义论证的提出大大扩展了逻辑学的研究范围,广义论证具有主体性、社会文化性、规则性、目的性和语境依赖性。在进行不同逻辑的对比研究时,不能用一种逻辑否定其他逻辑的合理性,而是在把一种逻辑的语言翻译成另一种逻辑的语言时进行必要的修正,以体现逻辑的特殊性。这种修正不仅能够降低由于逻辑语言不同而导致的对比研究困难,而且能体现逻辑的文化相对性,并按照这样的方法具体分析了形式逻辑和佛教逻辑五支论式的对比。然后用图尔敏模式分析三段论、五支论式和其他逻辑的论证结构。     

二元均值定理的高等证法

用微积分、线性代数、概率论等高等数学知识证明了二元均值定理,其证法的多样性引起了广泛的兴趣和讨论。     

基于支持向量机的储层参数反演

支持向量机是基于统计学理论的一种新的数学方法,近几年得到了快速的发展,国内外已将其应用到各个领域。该文应用支持向量回归机的方法,用测井数据、地震属性数据对储集层的储层参数进行了预测,得到了精度较高的储层参数;并通过对实验结果的分析,说明了这种方法的优势。