一个（1＋1）-维孤子方程的精确解

主要考虑一个（1＋1）-雏孤子方程,介绍了有关孤子理论和Hirota方法,通过适当的变量代换,将孤子方程化为双线性导数形式的微分方程,从方程的双线性导数形式出发,用摄动法得到孤子方程的n-孤子解．     

Hirota方法在孤子方程中的应用

主要考虑一个重要的孤子方程:BLMP-方程.介绍了有关孤子理论和Hirota方法,通过适当的变量代换,将孤子方程化为双线性导数形式的微分方程,从方程的双线性导数形式出发,用摄动法得到孤子方程的n-孤子解,最后又求得它的另外一种形式的Wronsky-解.     

一个(2+1)-维浅水波方程的精确解

主要考虑一个浅水波方程,介绍了有关孤子理论和双线性算子的定义,通过变量代换,将孤子方程化为双线性形式的微分方程,再从方程的双线性导数形式出发,利用摄动法得到了孤子方程的n-孤子解.最后又求出它另外一种形式的Wronsky-解.     

一类二阶非线性Schrdinger方程的孤子解

通过适当的变量代换将一类二阶非线性Schrdinger方程化成双线性导数方程,再利用Mathematica软件与截断技术,求得非线性Schrdinger方程的单孤子解、双孤子解与多孤子解。     

含修正项的KdV方程是否一定存在孤子尾

含修正项的KdV方程是否一定存在孤子尾是最近孤子理论中争论的中心问题之一。给出几类含修正项的KdV方程的精确解，证明含修正项的KdV方程不一定存在孤子尾。     

广义偶合KdV孤子方程的达布变换及其精确解

与广义偶合KdV孤子方程相联系的谱问题的达布变换在这篇文章中被讨论.迭布变换是用来产生广义偶合KdV孤子方程的精确解.孤子方程的一些有趣的解被得到.     

孤子方程的广义对称与S—G型方程的遗传强对称

给出了孤子方程的广义对称概念,求出了几个孤子方程的广义对称族。同时将Ｓ－Ｇ方程的遗传强对称推广到一般的Ｓ－Ｇ型方程。     

N孤子相互作用的弹性散射研究

大批有孤子解的非线性波动方程在物理的各领域不断被揭示,其中包括等离子体中非线性的Schroedinger方程、浅水波的KDV方程、振子运动的TODA链与二维流体流动的KP方程等。但对孤子解的物理学行为,却很少有文章讨论。文章从孤子的波动解出发,研究了两孤子相互作用的弹性散射,进而进一步将其推广到N孤子的弹性散射,得出了孤子散射的一般理论及其孤子行进的力学行为,对研究孤子的物理性质具有一定的指导意义。     

N孤子相互作用的弹性散射研究

大批有孤子解的非线性波动方程在物理的各领域不断被揭示,其中包括等离子体中非线性的Schr dinger方程、浅水波的KDV方程、振子运动的TODA链与二维流体流动的KP方程等。但对孤子解的物理学行为,却很少有文章讨论。文章从孤子的波动解出发,研究了两孤子相互作用的弹性散射,进而进一步将其推广到N孤子的弹性散射,得出了孤子散射的一般理论及其孤子行进的力学行为,对研究孤子的物理性质具有一定的指导意义。     

(2+1)维破裂孤子方程的多孤子解

使用齐次平衡方法，得到了（2＋1）维破裂孤子方程的一些新多孤子解，齐次平衡方法，能使复杂的（2＋1）维破裂孤子方程转化为简单的线性偏微分方程和双线性偏微分方程，然后通过特定的拟解，便可构造出（2＋1）维破裂孤子方程的丰富的孤子结构。     

Anisotropic Open Cosmological Models of Spin Matter with Magnetic Moment

We have derived a set of field equations for a Weyssenhoff spin fluid including magnetic interacton among the spinning particles prevailling in spatially homogeneous,but anisotropically cosmological models of Bianchi type V based on Einstein-Cartan theory.We analyze the field equations in three different equations of states specified by p=1(1/3)ρand p=0,The analytical solutions found are non-singular provided that the combined energy arising from matter spin and magnetic interaction among particles overcomes the anisotropy energy in the Universe,We have also deduced that the minimum particle numers for the radiation(p=(1/3)ρ) and matter(p=0) epochs are 10^88 and 10^108 respectively.the minimum particle number for the state p=ρ is 10^96,leading to the conclusion that we must consider the existence of neutrinos and other creation of particles and anti-particles under torsion and strong gravitational field in the early Universe.     

Dynamic modeling of micro- and nano-sized particles impinging on the substrate during suspension plasma spraying

Suspension plasma spraying (SPS) can be utilized to manufacture finely structured coatings. In this process, liquid suspended with micro- or nano-sized solid particles is injected into a plasma jet. It involves droplet injection, solvent evaporation, and discharge, acceleration, heating, and melting of the solid particles. The high-speed and high-temperature particles finally impact on the substrate wall, to form a thin layer coating. In this study, a comprehensive numerical model was developed to simulate the dynamic behaviors of the suspension droplets and the solid particles, as well as the interactions between them and the plasma gas. The plasma gas was treated as compressible, multi-component, turbulent jet flow, using Navier-Stokes equations solved by the Eulerian method. The droplets and solid particles were treated as discrete Lagrangian entities, being tracked through the spray process. The drag force, Saffman lift force, and Brownian force were taken into account for the aerodynamic drag force, aerodynamic lift force, and random fluctuation force imposed on the particles. Spatial distributions of the micro- and nano-sized particles are given in this paper and their motion histories were observed. The key parameters of spray distribution, including particle size and axial spray distance, were also analyzed. The critical size of particle that follows well with the plasma jet was deduced for the specified operating conditions. Results show that in the downstream, the substrate influences the flow field structure and the particle characteristics. The appropriate spray distances were obtained for different micro- and nano-sized particles.     

Random Model and Simulation for Nucleation Stage of Emulsion Polymerization

Mathematicalmodelsandsimulationsofemulsionpolymerizationhavebeenstudiedforseveraldecades .Re cently ,averycomprehensivereviewofithasbeenpub lished[1] .Infact,sincethephysicalmodelofemulsionpolymerizationwasfirstproposedbyHarkins[2— 4 ] inlate194 0s ,manyscientistsandengineersdevotedtheiratten tiontothequantitativeresearchofemulsionpolymeriza tion .ThemostimportantandfamoustheorywastheclassicaltheoryestablishedbySmithandEwart[5— 7] .Onthebasisofaseriesofreasonablysimplifiedassumptions ,Smit…     

理论物理中的一组矩阵

矩阵作为线性代数的主要研究对象,已成为高科技领域不可缺少的工具。本文从描述高速运动的自由粒子提出问题,对μ粒子的波方程进行扩充,得到了量子力学中的一组矩阵方程,并给出了它的一个初等证明。     

Motion and orientation of cylindrical and cubic particles in pipe flow with high concentration and high particle to pipe size ratio

Lattice Boltzmann method was used to numerically investigate the motion and orientation distribution of cylindrical and cubic particles in pipe flow with high concentration and high particle to pipe size ratio. The transient impulse model of 3D collisions between particles and between particle and wall is proposed. The numerical results are qualitatively in agreement with and quantitatively comparable to the experiment data. The results show that the increases of both the cylindrical particle to pipe size ratio and the particle aspect ratio decrease the rotation about all axes. All rotations of cubic particles decrease with increasing the particle concentration. The cubic particles, rotating more drastically in the flow with large Reynolds number, rotate faster than the cylindrical particles with the same size. The cylindrical particles align with the flow direction more obviously with decreasing Reynolds numbers. However, the orientations of cubic particles are spread all over the range with no significant difference in magnitude, and the Reynolds numbers have no obvious effect on the orientations of cubic particles.     

颗粒在流体中相互作用的晶格玻尔兹曼方法模拟

运用晶格玻尔兹曼方法研究了两个颗粒在Poiseuille流中的运动行为.分析了颗粒直径和管道直径之比d/D对颗粒相互作用的影响;讨论了颗粒的水平距离、颗粒的平衡位置与颗粒直径之间的关系.研究发现当d/D小于0.5时,颗粒的水平距离稳定在4.2倍的颗粒直径左右.研究对于理解多颗粒系统中颗粒之间的相互作用等具有一定的价值.     

A meshless method based on moving least squares for the simulation of free surface flows

In this paper, a meshless method based on moving least squares (MLS) is presented to simulate free surface flows. It is a Lagrangian particle scheme wherein the fluid domain is discretized by a finite number of particles or pointset; therefore, this meshless technique is also called the finite pointset method (FPM). FPM is a numerical approach to solving the incompressible Navier-Stokes equations by applying the projection method. The spatial derivatives appearing in the governing equations of fluid flow are obtained using MLS approximants. The pressure Poisson equation with Neumann boundary condition is handled by an iterative scheme known as the stabilized bi-conjugate gradient method. Three types of benchmark numerical tests, namely, dam-breaking flows, solitary wave propagation, and liquid sloshing of tanks, are adopted to test the accuracy and performance of the proposed meshless approach. The results show that the FPM based on MLS is able to simulate complex free surface flows more efficiently and accurately.     

基于GAPSO-SVM的滚动轴承故障分类方法

针对滚动轴承故障分类准确率低的问题,提出一种利用遗传算法结合粒子群算法优化支持向量机分类器的故障诊断方法.实验通过提取滚动轴承不同故障状态下的振动信号,以转化成时域和频域组成的特征集为特征向量,利用粒子群生成二维粒子,即惩罚因子C、核函数参数G,并喂入支持向量机进行训练和交叉验证,取最优适应度对应的粒子,进而构建遗传粒...     

磁性纳米粒子尺寸可控合成的研究

采用柠檬酸盐溶胶-凝胶法制备Ba2Co2Fe12O22铁氧体,在热处理阶段,分别通过控制热处理的温度和时间来制备不同粒径大小的磁性纳米粒子,利用高分辨率激光粒度仪分析测试在不同条件下获得的铁氧体,同时探讨了反应溶液不同的PH值对合成的影响。实验结果表明,延长加热时间和提高热处理温度都会使纳米粒子的粒径增大,在PH值略高...     

交流电热效应操控纳米粒子在芯片实验室中的应用

为寻求一种驱动电导率(大于0.02S/m)溶液的新方法,探讨了利用交流电热效应驱动高电导率微流体.根据交流电热效应理论,建立了交流电热粒子诱捕物理模型,利用仿真软件FEMLAB对其进行仿真分析研究,并通过实验对其进行验证.实验结果表明:利用特定的微电极芯片结构和交流电热效应,能驱动流体电导率高达1.53S/m的微流体,实现了在低电势下的粒子诱捕.利用交流电热效应驱动微流体,不仅能够实现对微粒的诱捕,而且输入信号电势低,受微流体影响小,容易与芯片集成.研究结果为设计交流电热效应芯片实验室提供了参考依据.