Applied Mathematics and Mechanics (English Edition)

THE HAMILTONIAN STRUCTURES OF 3D ODE WITH TIME-INDEPENDENT INVARIANTS

郭仲衡;陈玉明

1995, 16(4): 301-306.

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We have proved that any 3-dimensional dynamical system of ordinary differentialequations(in short, 3D ODE)With time-independent invariants can be rewritten as Haniltonian systems with respect to generalized Poisson brackets and theHamiltonians are these invariants. As an example,we discuss the Kermack-Mckendrick modelfor epidemics in detail. The results we obtained are generalizatioof those obtained by Y. Nutku.

INTERACTION BETWEEN CRACK AND ELASTIC INCLUSION

张明焕;汤任基

1995, 16(4): 307-318.

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A more general lopologically finite intersection property is obtained. As anapplication,we utilize this result to obtain some more general minimax theorems. Theresults presented in this paper unify and extend the main results of [5, 6, 9].

THE MECHANICAL METHOD OF CONSTRUCTING THE DISPLACEMENT FUNCTIONS IN ELASTICITY

张鸿庆;冯红

1995, 16(4): 335-344.

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In this Paper we have proven the general solution to the equations of linear operatorsAu=f as u=Cv+e. where v satisfies the equation Dv=g and D is adiagonal matrix. Basing on the consstructive proof of Hilbert Nullstellensatz. we haregiven the mechanical method of constucting C. D and e.and some of the mechanicalalgorithm displacement functions in elasticity are given by this method also.

UNSTEADY ROTATIVE FLOW OF NON-NEWTONIAN FLUID IN AN ANNULAR PIPE

黄军旗;刘慈群

1995, 16(4): 345-350.

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This paper.Studies power law no-Newtonian fluid rotative flow. in an annularpipe. The governing equation is nonlinear one, we linearized the governing equationby assuming that partial factor is at state. With Laplace transform we obtain ananalytical solution of the problem In the paper several groups of curves are given.these curves reflect the temporal change law and. spatial distribution of fluid velocity.In addition.we study the effection of power law index on the flow field the resultindicates that when the power law index n < 1. the flow velocity is highly sensitive tothe index. and this fact is importanl in related engineering decisions.

AN ITERATIVE METHOD FOR THE DISCRETE PROBLEMS OF A CLASS OF ELLIPTICAL VARIATIONAL INEQUALITIES

郑铁生;李立;许庆余

1995, 16(4): 351-358.

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Based on the nonlinear characiers of the discrete problems of some ellipticalvariational inequalities, this paper presents a numerical iterative method, the schemesof which are pithy and converge rapidly The new method possesses a high efficiency. insolving such applied engineering problems as obstacle problems and.free boundary.problems arising in fluid lubrications.

THE ECCENTRIC EFFECT OF A COAXIAL VISCOMETER

郭志荣;严宗毅

1995, 16(4): 359-367.

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This paper studies the effect of the eccentricity between the inner bob and theouter cup in a coaxial viscometer on the measurements of the viscosity., by using aperturbation scheme, Our numerical examples demonstrate that the error incurred bythe eccentricity would become larger as the characteristic Reynolds number decreasesor as the gap width between the bob and the cup gets narrower. However, such errorsmay not be signifcant if the eccentric distance is not larger than 1 10 of the gapwidth.for the usual working range of a coaxial viscometer.

VARIATIONAL PRINCIPLE AND GENERALIZED VARIATIONAL PRINCIPLE IN HYDRODYNAMICS OF A CLASS OF NON-NEWTONIAN FLUID

沈敏;孙其仁

1995, 16(4): 369-376.

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In this paper. the principle of maximum power losses for the incompressibleviscous fluid proposed by professor Chien Wei-zang is extended to the hydrodynamicproblems of a special class of non-Newtonian fluid-generalized Newtonian fluid.The constraint condition of variation are eliminated by the method of idetifiedLagrangian multipliers and a generalized variational principle is established.

AN APPLICATION OF SCHAUDER’S FIXED POINT THEOREM TO THE EXISTENCE OF SOLUTlONS OF IMPULSIVELY DIFFERENTIAL EQUATIONS

董玉君;邹尔新

1995, 16(4): 377-381.

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In this paper the existence of solutions of a boundary value problem forimpulsively differential equations that is difficult to solve by the upper and lowersolution method will be proved by means of Schauder’s fixed point theorem,whichimproves some existing results.

SECONDARY INSTABILITY OF LARGE SCALE STRUCTURE IN FREE TURBULENT SHEAR LAYER

赵耕夫

1995, 16(4): 383-389.

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The secondary instability theory is used to study the behavior of spatially growingdisturbance in free turbulent shear layer.The numerical results indicate that secondaryinstability of subharmonic mode shows a strong choice of spanwise wavenumber andthe maximum growth two dimensional case.In contrast to that secondary instabilities of the fundamental mode occur in a wide scope of spanwise wavenumber.We have found so called translative at β=0 and bifurcation phenomenon for an amplitude of the KH wave larger than 0.06.Dey words instability,large scale structure,bifurcation

RECIPROCAL THEOREM METHOD FOR SOLVING THE PROBLEMS OF BENDING OF THICK RECTANGULAR PLATES

付宝连;谭文锋

1995, 16(4): 391-403.

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In this paper,reciprocal theorem method(RTM) is generalized to solve theof bending of thick rectangular plates based on Reissner’s theory.First,the paper gives the basic solution of the bending of thick rectangular platesand then the exact analytical solution of the bending of thick rectangular plate withthree clamped edges and one free edge under umiformly distributed load is found by RTM, finally, we analyze numerical results of the sohution.

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