A THEORETICAL APPROACH TO THERMAL PROPERTY OF ARRAY OF CYLINDERS EMBEDDED IN HOMOGENEOUS MATRIX

We investigate in this article the thermal conductivity of array of cylinders embedded in a homogeneous matrix. Using Green's function, we confirm that the method invented by Rayleigh can be generalized to deal with thermal property of these systems. A technique for calculating effective thermal conductivities of these systems is proposed. As an example, we consider a system with square symmetry, and a neat formula for effective thermal conductivity is derived. We show that the method also includes the proof of Keller theorem.     

超流~3He、~4He溶液流体动力学方程——Ⅱ.超流~4He、~3He-A相溶液

在文[1]的基础上,我们继续用Lagrange不定乘子变分法推广Landau二流体超流理论到各向异性的超流氦溶液,得到关于超流4He、3He-A相的流体动力学方程。     

NEW METHOD FOR EFFECTIVE VISCOSITY OF COLLOIDAL DISPERSIONS WITH PERIODIC MICROSTRUCTURES

1IntroductionTherheologyofcolloidaldispersionisofinterestinmanyphsicalandtechnologicalproblems,andforthisreasonithasbeenstudiedextensively,expeciallywhenthesystemcallI)edescribedbythelillearNavier-StokesequationsforincompressibleNewtonianfiuicl[1--6J.ColIoidaldispersioncanbesubdividedintotwoclasses,namely,suspensionandemulsi.I,[7'8].Asuspensionisadispersionwithfinerigidparticlessuspendedinafluid.Inanemulsion,pallidparticlesareimmersedinanotherfluid.Animportantprobleminthisfieldistodeters-f…     

多孔和复合媒质直流电导率的计算方法(Ⅱ)——应用于各向同性和各向异性复合材料

本文系统地讨论了复合媒质直流电导率的第一性原理计算方法,导出了计算定域各向异性的复合材料的有效电导率的积分方程,提出了计算有效电导率张量的简便方法。我们计算了定域各向异性材料的有效电导率张量。还发展了计算无周期性的更一般的复合材料的理论方法。另外,本文提出积分方程近似计算的一种新方法(双基展开法)。该方法可用于对孔隙度大的复杂结构作精确的理论计算,并具有节省计算时间的优点。 关键词：     

含成层杂质的复合媒质的电导性质

本文用瑞利模型研究含成层杂质的复合媒质的直流电导性质,推导了适用于此类复合媒质的广义瑞利恒等式,并定义系统的有效电导率。对于具有立方对称性的系统,给出复合媒质有效电导率的解析计算公式。 关键词：     

超流溶液的本构方程

本文应用Green和Naghdi等人发展起来的现代连续介质力学理论,讨论了超流溶液的宏观描述问题,并建立了超流溶液的本构方程.     

TWO-DIMENSIONAL CELLULAR AUTOMATON TRAFFIC MODELWITH RANDOMLY SWITCHING TRAFFIC LIGHTS

I.IntroductionWiththedevelopmentofsocietyandeconomyinmetropolises,thecontradictionbet\"eentheincreaseoftrat'ficflowandtheexistingconditionoftrafticftlcilitiesbecolllesmorealldmore'serious,resultinginaprincipalI'actorofconstrainingthedevelopmentofmetropolititneconomy.Therefore,inrecentdecadesthetrat'l'ictlowproblemhasdrawntheattelltiollofInanyspecialistsinvariousfieldsincludingphysics,mechanicsalldmathelllatics.Alargenumberoftraftic1llodelshavebeenpropes.Inthispaper,thecellularautomaton(CA)tr…     

Dielectric responses of graded composites having generalized gradation profiles

Under an external uniform electric field, the dielectric response of graded cylindrical composites having generalized dielectric profile inclusions is investigated. The generalized dielectric profile of graded cylindrical inclusion is expressed in the form, $\varepsilon _i (r)=c(b+ r)^k\e^{\beta r}$ where $r$ is the radial variable of the cylindrical inclusions and $c$, $b$, $k$ and $\beta $ are parameters. The local potential solution of generalized dielectric profile graded composites is derived by means of the power series method and the effective dielectric response is predicted in the dilute limit. Moreover, from the result of generalized profile, the analytical solutions of local potentials and the effective responses of graded composites having three cases of dielectric profiles, i.e., the exponential profile $\varepsilon_\i (r)=c\e^{\beta r}$, the general power law profile $\varepsilon_\i (r)=c(b+r)^k$ and the profile $\varepsilon_\i (r)=cr^k\e^{\beta r}$, are sorted out, respectively. In the dilute limit, our exact results are used to test the validity of differential effective dipole approximation (DEDA) for estimating the effective response of graded cylindrical composites, and it is shown that the DEDA is in excellent agreement with the exact result.     

A theoretical research to effective viscosity of colloidal dispersions

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胶体有效粘滞系数的理论研究

胶体是自然界和工业应用中的常见对象。胶体领域的一个中心理论问题是如何根据胶体系统的微结构来确定胶体的流变性质。由于处理多粒子系统边值问题的困难,现有的胶体理论都局限于低颗粒浓度。该文中发展了变换场方法,用该方法可以计算含胶体颗粒的不可压缩粘滞流体的有效粘滞系数,颗粒可以是固体也可以是流体。在低颗粒浓度,该理论预测与爱因斯坦关于悬浮体的公式以及Taylor关于乳浊液的公式完全吻合。在高颗粒浓度,该文的结果与Nunan和Keller的结果相一致,其方法可以用于预测非球形颗粒悬浮体的有效粘滞系数。