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1998年 第19卷 第9期    刊出日期：1998-09-18

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论文

TWO-DIMENSIONAL CELLULAR AUTOMATON TRAFFIC MODEL WITH RANDOMLY SWITCHING TRAFFIC LIGHTS

顾国庆;许伯铭;汪秉宏;戴世强

1998, 19(9):  807-813. 

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Cellular automaton traffic models can include various .factors in traffic systems and the corresponding conutational simulations are rather simple and effecive, The Billam-Middleton model (BML model facilitates the simulation of twodimensional traffic flow problems via the cellular automaton models. In this paper, the BML model is improved by removing its limitation of syncronized change of trafficlights. In the new model, the traffic light at each crossing could arbilrarliy, change its starting time and tempo of variution, and hence thc model more more realitically describe the influence of traffic lights on the performance of traffic systems. Some new effects appearing in the new nodel are also elucidated.

NONLINEAR SEMIGROUPS AND DIFFERENTIAL INCLUSIONS IN PROBABILISTIC NORMED SPACES

张石生;陈玉清

1998, 19(9):  815-829. 

摘要 ( 552 )   PDF (689KB) ( 421 )  

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The purpose of this poper is to introduce and study the semi-groups of nonlinearcontractions in probabilislic normed spaces and to establish the Crandall-Linggett's exponential formula for some kind of accrelive mappings in probabilistic normed spaces. As applications. these results are utilized to study, the Cauchy problem for akind of differential inclusions with accretive mappings in probabilistic normed spaces.

BEST APPROXIMATION THEOREM FOR SET-VALUED MAPPINGS WITHOUT CONVEX VELUES AND CONTINUITY

丁协平;何诣然

1998, 19(9):  831-836. 

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In this paper, a new concept of weakly ,convex graph for set-valued mappings is introduced and studied. By using the concept, some new coincidence, the bestapproximation and fixed point-theorems are obtained.

CONNECTIONS AND GEODESIC CHARACTERISTIC OF EQUATIONS OF MOTION FOR CONSTRAINED MECHANICAL SYSTEMS

罗绍凯;郭永新;梅凤翔

1998, 19(9):  837-842. 

摘要 ( 502 )   PDF (404KB) ( 370 )  

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The geodesic characteristic of equations of motion for nonautonomous constrainedmechanical systems is studied in the modern setting of global differential geometry. Anecessary and sufficient condition for the dynamical flow of a monautonomous mechanical system with geodesic characteristic was obtained with respect to aconnection on jet bundle. The dynamical flow concerning the non-autonomous casewas always of geodesic characteristic with regard to torsion-free connections. Thus the motion of any nonautonomous mechanical system with constraints can be alwaysrepresented by the motion along the geodesic line of torsion-free connection on 1-jetbundle, which is different from the case in an autonomous mechaincal system.

SZEBEHELY'S PROBLEM FOR NONHOLONOMIC SYSTEMS WITH A GIVEN FIRST INTEGRAL

朱海平

1998, 19(9):  843-849. 

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An inverse problem for nonholonomic systems is studiedin. The equations of motion of nonholonomic systems are given. and the Szebehely's problem for a mechanical system with homogeneous nonholonomic constraints is considered, and the generulnonholonomic systems with a given first integral are studied.

ON ANALYSIS OF THE STEADY FLOW IN AN IRRECTANGULAR PARALLEL-PLATE FLOW CHAMBER

覃开荣;姜伟元;李惜惜;柳兆荣

1998, 19(9):  851-859. 

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The parallel-plate flow chamber (PPFC), of which the height is far smaller thanits own length and width is one of the main apparatus for the in vitro study of the mechanical behaviors of cultured cells at the bottom of PPFC undergoing shear stress.The PPFC of which the upper and lower plates are rectangular is usually used by research workers. and the flow field in this kind of PPFC (exeept for the regions near the entrance and exit is unifrom[1], so only the effect the shear the shear stress with one value has on cultured cells can be observed during each experiment .A kind of of PPFC of which the upper and lower plates are not rectangular is proposed in this paper. The distributions of the velocities inside and the shear stresses at the bottom of the chamber are given by analyzing the flow field of the steady flow in the PPFC. Theresults show that the mechanical behaviors of cultured cells undergoing the shearstresses with various values may be simultaneously observed by the use of this kind of irreclangular PPFC. The theoretical and experimental results obtained by Ultrasonic Doppler Technique show good agreement.

DISTURBANCES TO A ROTATING FLUID WITH A SPHERE MOVING ALONG THE AXIS OF ROTATION

乐嘉春

1998, 19(9):  861-866. 

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In this paper. the disturbances ic a uniformly rotating ideal fluid with a spheremoving steadily along the axis of rotation are analysed by using linearization theory,the equations of disturbance pressure and disturbance stream function governing the stability of motion are derived based on the assumption that the flow is rotational symmetric. The equation of disturbance stream function is analysed with the method ofnormal modes, and the constraints on wave number and wave velocity of the nontrivial neutral disturbances are established and the exact expression of the neutral disturbances are obtained. The conclusion is drawn that there are three kinds of possible forms of neutral disturbances.

DIFFERENTIAL GEOMETRICAL METHOD IN ELASTIC COMPOSITE WITH IMPERFECT INTERFACES

童金章;关凌云;张清杰

1998, 19(9):  869-879. 

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A differential geometrical method is for the first time used to calculate the effective nmoduli of a two-phase elastic composite materials with imperfect interface which the inclusions are assumed to be ellipsoidal of revolutions. All of the interface integral items participuting in forming the potential and coplementary energyfunctionals of the composite materials are expressed in terms of intrinsic quantities of the ellipsoidal of revolutions. Based on this, the upper and the lower bound for theeffective elastic moduli of the composite materials with inclusions descrbed above have been derived. Under three limiting conditions of sphere, disk and needle shapedinclusions, the results of this paper will return to the bounds obtained by Hashin[6](1992).

CML MODELS AND THE NONLINEARITY OF TURBULENCE

刘兆存

1998, 19(9):  881-887. 

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Some new coupled map lattice (CML) models are developed for simulating both convection, diffusion and weakly or strongly terms. The structure and features of model are analysed. Numerical results show that the new models are effective for studying spatiotemporal chaos. Finally. the mechanism of turbulence isanalysed via the numerical results.

ON THE SOLUTION OF NONLINEAR TWOPOINT BOUNDARY VALUE PROBLEM──u”+g(t.u)=f(t),u(0)=u(2π)=0

黄文华;曹菊生;沈祖和

1998, 19(9):  889-894. 

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In this paper, a non-variational version of a max-min principle is proposed, andan existence and uniqueness result is obtained for the nonlinear two-point boundaryvalue problenl u"+g(t.u)=f(t),u(0)=u(2π)=0

HIGHER-ORDER MULTIVARIABLE EULER'S POLYNOMIAL AND HIGHER-ORDER MULTIVARIABLE BERNOULLI'S POLYNOMIAL

刘国栋

1998, 19(9):  895-906. 

摘要 ( 548 )   PDF (548KB) ( 321 )  

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In this paper, the definitons of both higher-order multivariable Euler's numbersand polynomial. higher-order multivariable Bernoulli's numbers and polynomial aregiven and some of their important properties are expounded. As a result, themathematical relationship between higher-order multivariable Euler's polynomial(numbers) and higher-order higher -order Bernoulli's polynomial (numbers) are thusobtained.

A NEW TECHNIQUE FOR SOLVING NON-AXIALLY SYMMETRICAL LARGE DEFLECTION OF ELASTIC AND THIN CIRCULAR PLATES

郭毅;王桂芳

1998, 19(9):  907-916. 

摘要 ( 539 )   PDF (505KB) ( 296 )  

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A new technique for solving large deflection problem of circular plates fixuralnon-axisymmetrically is proposed in this poper. The large deflection problent of acircular plate with built-in edge under non-axisymmetrical load is taken as an exompleto clarify. the principle and procedure of the technique mentioned here. The technique given here can also be used to solve large deflection problem of circular plaies under other non-axisymmetrical loads and boundary conditions.