The aim of this paper is to study the reflection of plane harmonic waves from a semi-infinite elastic solid under the effect of magnetic field in a vacuum.The expressions for the reflection coefficients,which are the ...The aim of this paper is to study the reflection of plane harmonic waves from a semi-infinite elastic solid under the effect of magnetic field in a vacuum.The expressions for the reflection coefficients,which are the relations of the amplitudes of the reflected waves to the amplitude of the incident waves,are obtained.Similarly,the reflection coefficient ratio variations with the angle of incident under different conditions are shown graphically.Comparisons are made with the results predicted by the dual-phase-lag model and Lord-Shulman theory in the presence and absence of magnetic field.展开更多
This paper gives a new definition of the filled function for nonlinear integer programming problem. A filled function satisfying our definition is presented. This function contains only one parameter. The properties o...This paper gives a new definition of the filled function for nonlinear integer programming problem. A filled function satisfying our definition is presented. This function contains only one parameter. The properties of the proposed filled function and the method using this filled function to solve nonlinear integer programming problem are also discussed. Numerical results indicate the efficiency and reliability of the proposed filled function algorithm.展开更多
The aim of this paper is to study the effects of rotation and magnetic field on the plane vibrations in a transversely isotropic material of an infinite hollow cylinder.The natural frequency of the plane vibrations in...The aim of this paper is to study the effects of rotation and magnetic field on the plane vibrations in a transversely isotropic material of an infinite hollow cylinder.The natural frequency of the plane vibrations in the case of harmonic vibrations has been obtained.The natural frequencies are calculated numerically and the effects of rotation and magnetic field are discussed.The numerical results obtained have been illustrated graphically to understand the behavior of frequency equation with different values of frequencyωunder effects the rotation and magnetic field.Comparison was made with the results obtained in the presence and absence of the rotation and magnetic field.The results indicate that the effect of rotation and magnetic field are very pronounced.展开更多
In this paper, we investigated the propagation of magneto-thermoelastic surfacewaves in fibre-reinforced anisotropic general viscoelastic media of higher order ofnth order,including time rate of strain under the influ...In this paper, we investigated the propagation of magneto-thermoelastic surfacewaves in fibre-reinforced anisotropic general viscoelastic media of higher order ofnth order,including time rate of strain under the influence of rotation and magnetic field.The generalsurface wave speed is derived to study the effects of rotation, magnetic field and thermal onsurface waves. Particular cases for Stoneley, Love and Rayleigh waves are discussed. Theresults obtained in this investigation are more general in the sense that some earlier publishedresults are obtained from our result as special cases. Our results for viscoelastic of order zeroare well agreed to fibre-reinforced materials. Comparison was made with the results obtainedin the presence and absence of rotation, magnetic field and parameters for fibre-reinforced ofthe material medium. It is also observed that, surface waves cannot propagate in a fast rotatingmedium. Numerical results for particular materials are given and illustrated graphically. Theresults indicate that the effect of rotation, magnetic field on fibre-reinforced anisotropic generalviscoelastic media are very pronounced.展开更多
In the light of great importance of curves and their frames in many differentbranches of science, especially differential geometry as well as geometric properties andthe uses in various fields, we are interested here ...In the light of great importance of curves and their frames in many differentbranches of science, especially differential geometry as well as geometric properties andthe uses in various fields, we are interested here to study a special kind of curves calledSmarandache curves in Lorentz 3-space. Then, we present some characterizations for thesecurves and calculate their Darboux invariants. Moreover, we classify TP, TU, PU andTPU-Smarandache curves of a spacelike curve according to the causal character of thevector, curve and surface used in the study. Besides, we give some of differential geometricproperties and important relations between that curves. Finally, to demonstrate ourtheoretical results a computational example is given with graph.展开更多
This paper surveys some new results on the oscillation of all solutions of the linear nentral delaydifference equation of the form △(y<sub>n</sub> - p<sub>n</sub>y<sub>n-k</sub>) +...This paper surveys some new results on the oscillation of all solutions of the linear nentral delaydifference equation of the form △(y<sub>n</sub> - p<sub>n</sub>y<sub>n-k</sub>) + q<sub>n</sub>y<sub>n-l</sub> = 0, n = 0,1, 2…where { p<sub>n</sub> } and { q<sub>n</sub> } are twe real numbers sequences with q<sub>n</sub>≥0, and k and l are positive integers. These re-sults do not require the usual assumptionAlso, some interesting open problems on this topic am given.展开更多
The properties and characteristics of torque free gyros with rotational symmetry and changing moments of inertia are the subject of the subsequent discussion. It shall be understood that the symmetry can be expressed ...The properties and characteristics of torque free gyros with rotational symmetry and changing moments of inertia are the subject of the subsequent discussion. It shall be understood that the symmetry can be expressed by the notation (A=B) which does not presuppose geometric symmetry, where A and B are the principle moments of inertia about x and y axes respectively. We study the case of a torque free gyro upon which no external torque is acting. The equations of motion are derived when the origin of the xyz-coordinate system coincides with the gyro’s mass center c. This study is useful for the satellites, which have rotational symmetry and changed inertia moments, the antennas and the solar power collector systems.展开更多
In the present paper Cauchy integral methods have been applied to derive exact and expressions for Goursat’s function for the first and second fundamental problems of isotropic homogeneous perforated infinite elastic...In the present paper Cauchy integral methods have been applied to derive exact and expressions for Goursat’s function for the first and second fundamental problems of isotropic homogeneous perforated infinite elastic media in the presence of uniform flow of heat. For this, we considered the problem of a thin infinite plate of specific thickness with a curvilinear hole where the origins lie in the hole is conformally mapped outside a unit circle by means of a specific rational mapping. Moreover, the three stress components σxx, σyy and σxy of the boundary value problem in the thermoelasticity plane are obtained. Many special cases of the conformal mapping and four applications for different cases are discussed and many main results are derived from the work.展开更多
In this paper the fixed pansystems theorems concerning the composition-complement-operators are discussed. Some existence conditions of panchaos and strange panattractor are given. And using the results, some fixed po...In this paper the fixed pansystems theorems concerning the composition-complement-operators are discussed. Some existence conditions of panchaos and strange panattractor are given. And using the results, some fixed point theorems for many-valued mappings are also proved, which complement and develop the results obtained by Kakutani.展开更多
in this paper, we define some maps which are similar to the maps in [1,3]. We use these maps to prob the relative properties in a more general situation. In this case TMA ,TNB are two bimodules and M^* = Homr (M, N).
The analysis of seismic wave propagation and amplification in complex geological structures requires efficient numerical methods.In this article,following up on recent studies devoted to the formulation,implementation...The analysis of seismic wave propagation and amplification in complex geological structures requires efficient numerical methods.In this article,following up on recent studies devoted to the formulation,implementation and evaluation of 3-D single-and multi-region elastodynamic fast multipole boundary element methods(FM-BEMs),a simple preconditioning strategy is proposed.Its efficiency is demonstrated on both the single-andmulti-region versions using benchmark examples(scattering of plane waves by canyons and basins).Finally,the preconditioned FM-BEM is applied to the scattering of plane seismic waves in an actual configuration(alpine basin of Grenoble,France),for which the high velocity contrast is seen to significantly affect the overall efficiency of the multi-region FM-BEM.展开更多
Leti(y)=sum from j=o to n Pn-j(x)y~((j))be a symmetric differential expression on an interval I with deficiency index(m,m),O≤m≤n.It is well known from the general operator theory that the minimaloperator associated ...Leti(y)=sum from j=o to n Pn-j(x)y~((j))be a symmetric differential expression on an interval I with deficiency index(m,m),O≤m≤n.It is well known from the general operator theory that the minimaloperator associated with l(y) can be extended to a self-adjoint differential operator inL2(I).This gives rise to the question how to desoribe analytically all the self-adjoint extensions of the minimal operator of l(y).This question may also bestated as follows:given a differential expression l(y) as above,what are the oharac-展开更多
文摘The aim of this paper is to study the reflection of plane harmonic waves from a semi-infinite elastic solid under the effect of magnetic field in a vacuum.The expressions for the reflection coefficients,which are the relations of the amplitudes of the reflected waves to the amplitude of the incident waves,are obtained.Similarly,the reflection coefficient ratio variations with the angle of incident under different conditions are shown graphically.Comparisons are made with the results predicted by the dual-phase-lag model and Lord-Shulman theory in the presence and absence of magnetic field.
文摘This paper gives a new definition of the filled function for nonlinear integer programming problem. A filled function satisfying our definition is presented. This function contains only one parameter. The properties of the proposed filled function and the method using this filled function to solve nonlinear integer programming problem are also discussed. Numerical results indicate the efficiency and reliability of the proposed filled function algorithm.
文摘The aim of this paper is to study the effects of rotation and magnetic field on the plane vibrations in a transversely isotropic material of an infinite hollow cylinder.The natural frequency of the plane vibrations in the case of harmonic vibrations has been obtained.The natural frequencies are calculated numerically and the effects of rotation and magnetic field are discussed.The numerical results obtained have been illustrated graphically to understand the behavior of frequency equation with different values of frequencyωunder effects the rotation and magnetic field.Comparison was made with the results obtained in the presence and absence of the rotation and magnetic field.The results indicate that the effect of rotation and magnetic field are very pronounced.
文摘In this paper, we investigated the propagation of magneto-thermoelastic surfacewaves in fibre-reinforced anisotropic general viscoelastic media of higher order ofnth order,including time rate of strain under the influence of rotation and magnetic field.The generalsurface wave speed is derived to study the effects of rotation, magnetic field and thermal onsurface waves. Particular cases for Stoneley, Love and Rayleigh waves are discussed. Theresults obtained in this investigation are more general in the sense that some earlier publishedresults are obtained from our result as special cases. Our results for viscoelastic of order zeroare well agreed to fibre-reinforced materials. Comparison was made with the results obtainedin the presence and absence of rotation, magnetic field and parameters for fibre-reinforced ofthe material medium. It is also observed that, surface waves cannot propagate in a fast rotatingmedium. Numerical results for particular materials are given and illustrated graphically. Theresults indicate that the effect of rotation, magnetic field on fibre-reinforced anisotropic generalviscoelastic media are very pronounced.
文摘In the light of great importance of curves and their frames in many differentbranches of science, especially differential geometry as well as geometric properties andthe uses in various fields, we are interested here to study a special kind of curves calledSmarandache curves in Lorentz 3-space. Then, we present some characterizations for thesecurves and calculate their Darboux invariants. Moreover, we classify TP, TU, PU andTPU-Smarandache curves of a spacelike curve according to the causal character of thevector, curve and surface used in the study. Besides, we give some of differential geometricproperties and important relations between that curves. Finally, to demonstrate ourtheoretical results a computational example is given with graph.
基金Projects supported by the National Natural Science Foundation of China
文摘This paper surveys some new results on the oscillation of all solutions of the linear nentral delaydifference equation of the form △(y<sub>n</sub> - p<sub>n</sub>y<sub>n-k</sub>) + q<sub>n</sub>y<sub>n-l</sub> = 0, n = 0,1, 2…where { p<sub>n</sub> } and { q<sub>n</sub> } are twe real numbers sequences with q<sub>n</sub>≥0, and k and l are positive integers. These re-sults do not require the usual assumptionAlso, some interesting open problems on this topic am given.
文摘The properties and characteristics of torque free gyros with rotational symmetry and changing moments of inertia are the subject of the subsequent discussion. It shall be understood that the symmetry can be expressed by the notation (A=B) which does not presuppose geometric symmetry, where A and B are the principle moments of inertia about x and y axes respectively. We study the case of a torque free gyro upon which no external torque is acting. The equations of motion are derived when the origin of the xyz-coordinate system coincides with the gyro’s mass center c. This study is useful for the satellites, which have rotational symmetry and changed inertia moments, the antennas and the solar power collector systems.
文摘In the present paper Cauchy integral methods have been applied to derive exact and expressions for Goursat’s function for the first and second fundamental problems of isotropic homogeneous perforated infinite elastic media in the presence of uniform flow of heat. For this, we considered the problem of a thin infinite plate of specific thickness with a curvilinear hole where the origins lie in the hole is conformally mapped outside a unit circle by means of a specific rational mapping. Moreover, the three stress components σxx, σyy and σxy of the boundary value problem in the thermoelasticity plane are obtained. Many special cases of the conformal mapping and four applications for different cases are discussed and many main results are derived from the work.
文摘In this paper the fixed pansystems theorems concerning the composition-complement-operators are discussed. Some existence conditions of panchaos and strange panattractor are given. And using the results, some fixed point theorems for many-valued mappings are also proved, which complement and develop the results obtained by Kakutani.
文摘in this paper, we define some maps which are similar to the maps in [1,3]. We use these maps to prob the relative properties in a more general situation. In this case TMA ,TNB are two bimodules and M^* = Homr (M, N).
文摘The analysis of seismic wave propagation and amplification in complex geological structures requires efficient numerical methods.In this article,following up on recent studies devoted to the formulation,implementation and evaluation of 3-D single-and multi-region elastodynamic fast multipole boundary element methods(FM-BEMs),a simple preconditioning strategy is proposed.Its efficiency is demonstrated on both the single-andmulti-region versions using benchmark examples(scattering of plane waves by canyons and basins).Finally,the preconditioned FM-BEM is applied to the scattering of plane seismic waves in an actual configuration(alpine basin of Grenoble,France),for which the high velocity contrast is seen to significantly affect the overall efficiency of the multi-region FM-BEM.
文摘Leti(y)=sum from j=o to n Pn-j(x)y~((j))be a symmetric differential expression on an interval I with deficiency index(m,m),O≤m≤n.It is well known from the general operator theory that the minimaloperator associated with l(y) can be extended to a self-adjoint differential operator inL2(I).This gives rise to the question how to desoribe analytically all the self-adjoint extensions of the minimal operator of l(y).This question may also bestated as follows:given a differential expression l(y) as above,what are the oharac-
