Numerical Solution of Exterior Problems by the Peripheral Block Over-relaxation Method

The numerical solution of exterior problems involving ellipticpartial differential equations presents a formidable problem,even with present day computers and the recent improvementsin convergence rates of iterative methods. In this paper, the successive peripheral block over-relaxationmethod (SPOR) previously successively applied to a variety ofboundary value problems in annular and circular regions (Benson& Evans, 1972) is shown to be a suitable method for exteriorproblems.     

The Use of Pre-conditioning in Iterative Methods for Solving Linear Equations with Symmetric Positive Definite Matrices

The asymptotic convergence rates of many standard iterativemethods for the solution of linear equations can be shown todepend inversely on the P-condition number of the co-efficientmatrix. The notion of minimizing the P-condition number andhence maximizing the convergence rate by the introduction ofa new pre-conditioning factor is shown to be computationallyfeasible. The application of this idea to the method of SimultaneousDisplacement, Richardson's method and other iterative methods,are discussed and numerical examples given to illustrate itseffectiveness.     

On the validity of Fourier's law in systems with spatially varying strain rates

Non-equilibrium molecular dynamics (NEMD) simulations are used to study the generation of heat fluxes in systems with spatially varying shear rates. We show that the kinetic temperature, when used in Fourier's law of heat conduction, does not correctly account for the heat flux, and that the normal temperature as described by Rugh (1997, Phys. Rev. Lett., 78, 772), should be used. Only in the absence of normal temperature gradients can heat fluxes due to strain rate coupling be correctly calculated.     

层板Ni2+的引入对CuCr类水滑石晶体结构的影响研究

采用自行创制的成核晶化隔离法将Ni^2 引入层状双金属复合氢氧化物(LDHs)的层板,首次合成得到了层板含Ni^2 的三元金属铜镍铬的碳酸根型LDHs(CuNiCr—LDHs),通过X射线衍射(XRD)、红外光谱(FT-IR)、透射电镜(TEM)、热重及微商热重分析(TODTG)、等离子电感偶合元素分析(ICP)和激光粒度分析等手段对产物的晶体结构特征进行了研究,结果表明：当反应Cu^2 ／Ni^2 ／Cr^3 投料摩尔比介于1：2：1～1：3：1之间,晶化温度为180℃和晶化时间大于4h时,利用成核晶化隔离法可以合成得到晶型规整的CuNiCr—LDHs;研究同时发现,层板引入Ni^2 后可以削弱Cu^2 的Jahn-Tellex效应对层板对称性的影响,提高了LDHs的晶型完整性和结构稳定性。     

Studies on the Catalytic Properties of Magnesia Supported on γ-Alumina

ＩｎｔｒｏｄｕｃｔｉｏｎＧｌｙｃｏｌｅｔｈｅｒｓａｒｅｉｍｐｏｒｔａｎｔｉｎｄｕｓｔｒｉａｌｄｅｒｉｖａｔｉｖｅｓｏｆｅｐｏｘｉｄｅｓ .Ｐｏｌｙｅｔｈｙｌｅｎｅ ｇｌｙｃｏｌｅｔｈｙｌｅｔｈｅｒｓａｎｄｐｏｌｙｐｒｏｐｙｌｅｎｅｇｌｙｃｏｌｅｔｈｙｌｅｔｈｅｒｓａｒｅｔｗｏｉｍｐｏｒｔａｎｔｓｅｒｉｅｓｏｆｐｒｏｄｕｃｔｓ .Ｇｌｙｃｏｌｅｔｈｅｒｓａｒｅｇｏｏｄｓｏｌｖｅｎｔｓｄｕｅｔｏｔｈｅｐｒｅｓｅｎｃｅｏｆ—Ｏ—ａｎｄ—ＯＨ ｇｒｏｕｐｓ.Ａｓａｒｅ ｓｕｌｔ ,ｔｈｅｙａｒｅｗｉｄｅｌｙｕｓｅ…     

The Oscillating Water Column Wave-energy Device

An expression is obtained for the efficiency of wave-energyabsorption of a float connected to a spring-dashpot system onthe top of a column of fluid bounded by two closely-spaced verticalparallel plates or a narrow tube immersed under waves. The methodmakes extensive use of the approximate solution using matchedasymptotic expansions obtained by Newman (1974) to the correspondingproblem when the float-spring-dashpot system was absent. Itis shown that for plates of equal length the maximum possibleefficiency is 50%, and that for the three-dimensional case itis theoretically possible to capture the energy in a wave whosecrest length is greater than the tube diameter.     

广义Bethe树上奇偶马尔可夫链场上的若干极限性质

通过构造两个非负鞅证明了一个强极限定理,然后把它应用到本文所定义的广义Bethe树上的奇偶马尔可夫链场上,从而获得了此马氏链场上的一类强极限定理.