The time-fractional modified Korteweg-de Vries(KdV)equation is committed to establish exact solutions by employing the bifurcation method.Firstly,the phase portraits and related qualitative analysis are comprehensivel...The time-fractional modified Korteweg-de Vries(KdV)equation is committed to establish exact solutions by employing the bifurcation method.Firstly,the phase portraits and related qualitative analysis are comprehensively provided.Then,we give parametric expressions of different types of solutions matching with the corresponding orbits.Finally,solution profiles,3D and density plots of some solutions are presented with proper parametric choices.展开更多
The non-isospectral sine-Gordon equation with self-consistent sources is derived.Its solutions are obtainedby means of Hirota method and Wronskian technique,respectively.Non-isospectral dynamics including one-solitonc...The non-isospectral sine-Gordon equation with self-consistent sources is derived.Its solutions are obtainedby means of Hirota method and Wronskian technique,respectively.Non-isospectral dynamics including one-solitoncharacteristics,two-soliton scattering,and ghost solitons,are investigated.展开更多
In this paper,we consider the wick-type Kd V-Burgers equation with variable coefficients. By using Tanh method with the aid of Hermite transformation, we deduce the exact solutions which include hyperbolic-exponential...In this paper,we consider the wick-type Kd V-Burgers equation with variable coefficients. By using Tanh method with the aid of Hermite transformation, we deduce the exact solutions which include hyperbolic-exponential, trigonometric-exponential and exponential function solutions for the considered equation.展开更多
In this paper, coupled nonlinear Schr<span style="white-space:nowrap;">ö</span>dinger equations with variable coefficients are studied, which can be used to describe the interaction amon...In this paper, coupled nonlinear Schr<span style="white-space:nowrap;">ö</span>dinger equations with variable coefficients are studied, which can be used to describe the interaction among the modes in nonlinear optics and Bose-Einstein condensation. Some novel bright-dark solitons and dark-dark solitons are obtained by modified Sine-Gordon equation method. Moreover, some figures are provided to illustrate how the soliton solutions propagation is determined by the different values of the variable group velocity dispersion terms, which can be used to model various phenomena.展开更多
General exact solutions in terms of wavelet expansion are obtained for multiterm time-fractional difusion-wave equations with Robin type boundary conditions. By proposing a new method of integral transform for solving...General exact solutions in terms of wavelet expansion are obtained for multiterm time-fractional difusion-wave equations with Robin type boundary conditions. By proposing a new method of integral transform for solving boundary value problems, such fractional partial diferential equations are converted into time-fractional ordinary diferential equations, which are further reduced to algebraic equations by using the Laplace transform. Then, with a wavelet-based exact formula of Laplace inversion, the resulting exact solutions in the Laplace transform domain are reversed to the time-space domain. Three examples of wave-difusion problems are given to validate the proposed analytical method.展开更多
Based on the Biot theory of porous media,the exact solutions to onedimensional transient response of incompressible saturated single-layer porous media under four types of boundary conditions are developed.In the proc...Based on the Biot theory of porous media,the exact solutions to onedimensional transient response of incompressible saturated single-layer porous media under four types of boundary conditions are developed.In the procedure,a relation between the solid displacement u and the relative displacement w is derived,and the well-posed initial conditions and boundary conditions are proposed.The derivation of the solution for one type of boundary condition is then illustrated in detail.The exact solutions for the other three types of boundary conditions are given directly.The propagation of the compressional wave is investigated through numerical examples.It is verified that only one type of compressional wave exists in the incompressible saturated porous media.展开更多
The two coupled governing differential equations for the out-of-plane vibrations of non-uniform beams with variable curvature are derived via the Hamilton’s principle.These equations are expressed in terms of flexura...The two coupled governing differential equations for the out-of-plane vibrations of non-uniform beams with variable curvature are derived via the Hamilton’s principle.These equations are expressed in terms of flexural and torsional displacements simultaneously.In this study,the analytical method is proposed.Firstly,two physical parameters are introduced to simplify the analysis.One derives the explicit relations between the flexural and the torsional displacements which can also be used to reduce the difficulty in experimental measurements.Based on the relation,the two governing characteristic differential equations with variable coefficients can be uncoupled into a sixth-order ordinary differential equation in terms of the flexural displacement only.When the material and geometric properties of the beam are in arbitrary polynomial forms,the exact solutions with regard to the outof-plane vibrations of non-uniform beams with variable curvature can be obtained by the recurrence formula.In addition,the mode transition mechanism is revealed and the influence of several parameters on the vibration of the non-uniform beam with variable curvature is explored.展开更多
The Painlev'e integrability and exact solutions to a coupled nonlinear Schr¨odinger (CNLS) equation applied in atmospheric dynamics are discussed.Some parametric restrictions of the CNLS equation are given to...The Painlev'e integrability and exact solutions to a coupled nonlinear Schr¨odinger (CNLS) equation applied in atmospheric dynamics are discussed.Some parametric restrictions of the CNLS equation are given to pass the Painlev'e test.Twenty periodic cnoidal wave solutions are obtained by applying the rational expansions of fundamental Jacobi elliptic functions.The exact solutions to the CNLS equation are used to explain the generation and propagation of atmospheric gravity waves.展开更多
In the present paper, Lie group symmetry method is used to obtain some exact solutions for a hyperbolic system of partial differential equations(PDEs), which governs an isothermal no-slip drift-flux model for multipha...In the present paper, Lie group symmetry method is used to obtain some exact solutions for a hyperbolic system of partial differential equations(PDEs), which governs an isothermal no-slip drift-flux model for multiphase flow problem. Those symmetries are used for the governing system of equations to obtain infinitesimal transformations, which consequently reduces the governing system of PDEs to a system of ODEs.Further, the solutions of the system of ODEs which in turn produces some exact solutions for the PDEs are presented. Finally, the evolutionary behavior of weak discontinuity is discussed.展开更多
In this paper, a sufficient and necessary condition is presented for existence of a class of exact solutions to N-dimensional incompressible magnetohydrodynamic(MHD)equations. Such solutions can be explicitly expresse...In this paper, a sufficient and necessary condition is presented for existence of a class of exact solutions to N-dimensional incompressible magnetohydrodynamic(MHD)equations. Such solutions can be explicitly expressed by appropriate formulae. Once the required matrices are chosen, solutions to the MHD equations are directly constructed.展开更多
We study the one-dimensional general non-Hermitian models with asymmetric long-range hopping and explore how to analytically solve the systems under some specific boundary conditions.Although the introduction of long-...We study the one-dimensional general non-Hermitian models with asymmetric long-range hopping and explore how to analytically solve the systems under some specific boundary conditions.Although the introduction of long-range hopping terms prevents us from finding analytical solutions for arbitrary boundary parameters,we identify the existence of exact solutions when the boundary parameters fulfill some constraint relations,which give the specific boundary conditions.Our analytical results show that the wave functions take simple forms and are independent of hopping range,while the eigenvalue spectra display rich model-dependent structures.Particularly,we find the existence of a special point coined as pseudo-periodic boundary condition,for which the eigenvalues are the same as those of the periodical system when the hopping parameters fulfill certain conditions,whereas the eigenstates display the non-Hermitian skin effect.展开更多
In this paper,the Painlev'e properties of the modified C-KdV equation are verified by using the W-K algorithm.Then some exact soliton solutions are obtained by applying the standard truncated expansion method and ...In this paper,the Painlev'e properties of the modified C-KdV equation are verified by using the W-K algorithm.Then some exact soliton solutions are obtained by applying the standard truncated expansion method and the nonstandard truncated expansion method with the help of Maple software,respectively.展开更多
An exact solution of a single impurity model is hard to derive since it breaks translation invariance symmetry. We present the exact solution of the spin-1/2 transverse Ising chain imbedded by a spin-1 impurity. Using...An exact solution of a single impurity model is hard to derive since it breaks translation invariance symmetry. We present the exact solution of the spin-1/2 transverse Ising chain imbedded by a spin-1 impurity. Using the hole decomposition scheme, we exactly solve the spin-1 impurity in two subspaces which are generated by a conserved hole operator.The impurity enlarges the energy deformation of the ground state above a pure transverse Ising system without impurity.The specific heat coefficient shows a small anomaly at low temperature for finite size. This indicates that the impurity can tune the ground state from a magnetic impurity space to a non-magnetic impurity space, which only exists for spin-1impurity comparing with spin-1/2 impurity and a pure transverse Ising chain without impurity. These behaviors essentially come from adding impurity freedom, which induces a competition between hole and fermion excitation depending on the coupling strength with its neighbor and the single-ion anisotropy.展开更多
Based on the generalized Riccati relation,an algebraic method to construct a series of exact solutionsto nonlinear evolution equations is proposed.Being concise and straightforward,the method is applied to Maccari'...Based on the generalized Riccati relation,an algebraic method to construct a series of exact solutionsto nonlinear evolution equations is proposed.Being concise and straightforward,the method is applied to Maccari'ssystem,and some exact solutions of the system are obtained.The method is of important significance in exploring exactsolutions for other nonlinear evolution equations.展开更多
In this paper,a nonlinear wave equation with variable coefficients is studied,interestingly,this equation can be used to describe the travelling waves propagating along the circular rod composed of a general compressi...In this paper,a nonlinear wave equation with variable coefficients is studied,interestingly,this equation can be used to describe the travelling waves propagating along the circular rod composed of a general compressible hyperelastic material with variable cross-sections and variable material densities.With the aid of Lou’s direct method1,the nonlinear wave equation with variable coefficients is reduced and two sets of symmetry transformations and exact solutions of the nonlinear wave equation are obtained.The corresponding numerical examples of exact solutions are presented by using different coefficients.Particularly,while the variable coefficients are taken as some special constants,the nonlinear wave equation with variable coefficients reduces to the one with constant coefficients,which can be used to describe the propagation of the travelling waves in general cylindrical rods composed of generally hyperelastic materials.Using the same method to solve the nonlinear wave equation,the validity and rationality of this method are verified.展开更多
In this paper, the invariant subspaces of the generalized strongly dispersive DGH equation are given, and the exact solutions of the strongly dispersive DGH equation are obtained. Firstly, transform nonlinear partial ...In this paper, the invariant subspaces of the generalized strongly dispersive DGH equation are given, and the exact solutions of the strongly dispersive DGH equation are obtained. Firstly, transform nonlinear partial differential Equation (PDE) into ordinary differential Equation (ODE) systems by using the invariant subspace method. Secondly, combining with the dynamical system method, we use the invariant subspaces which have been obtained to construct the exact solutions of the equation. In the end, the figures of the exact solutions are given.展开更多
In this paper, we investigate an integrable high order nonlocal coupled Ablowitz-Kaup-Newell-Segur (AKNS) system for the first time. With the aid of Lax pair of this nonlocal system, Darboux transformation (DT) and ne...In this paper, we investigate an integrable high order nonlocal coupled Ablowitz-Kaup-Newell-Segur (AKNS) system for the first time. With the aid of Lax pair of this nonlocal system, Darboux transformation (DT) and new soliton-like solutions are obtained. Different from local equations, Darboux transformation of nonlocal systems needs to meet certain conditions. In this article, under the condition of symmetry reduction, the components of Darboux transformation need to satisfy <img src="Edit_6aa5df34-2f85-4c91-a185-17195a7f82ee.bmp" alt="" />. In order to study the dynamic information of the solutions, the images of the solutions are given.展开更多
The current work aims to present abundant families of the exact solutions of Mikhailov-Novikov-Wang equation via three different techniques.The adopted methods are generalized Kudryashov method(GKM),exponential ration...The current work aims to present abundant families of the exact solutions of Mikhailov-Novikov-Wang equation via three different techniques.The adopted methods are generalized Kudryashov method(GKM),exponential rational function method(ERFM),and modified extended tanh-function method(METFM).Some plots of some presented new solutions are represented to exhibit wave characteristics.All results in this work are essential to understand the physical meaning and behavior of the investigated equation that sheds light on the importance of investigating various nonlinear wave phenomena in ocean engineering and physics.This equation provides new insights to understand the relationship between the integrability and water waves’phenomena.展开更多
In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 eq...In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 equation, Joseph-Egri (TRLW) equation, and Calogro-Degasperis (CD) equation. As a result, we have obtained solutions for the equations expressed in terms of trigonometric, hyperbolic and rational functions. Moreover, some selected solutions are plotted using some specific values for the parameters.展开更多
基金Project supported by the Natural Science Foundation of Shandong Province (Grant No.ZR2021MA084)the Natural Science Foundation of Liaocheng University (Grant No.318012025)Discipline with Strong Characteristics of Liaocheng University–Intelligent Science and Technology (Grant No.319462208)。
文摘The time-fractional modified Korteweg-de Vries(KdV)equation is committed to establish exact solutions by employing the bifurcation method.Firstly,the phase portraits and related qualitative analysis are comprehensively provided.Then,we give parametric expressions of different types of solutions matching with the corresponding orbits.Finally,solution profiles,3D and density plots of some solutions are presented with proper parametric choices.
基金The project supported by National Natural Science Foundation of China under Grant No.10371070 the Foundation of Shanghai Education Committee for Shanghai Prospective Excellent Young Teachers
文摘The non-isospectral sine-Gordon equation with self-consistent sources is derived.Its solutions are obtainedby means of Hirota method and Wronskian technique,respectively.Non-isospectral dynamics including one-solitoncharacteristics,two-soliton scattering,and ghost solitons,are investigated.
基金Supported by the National Natural Science Foundation of China(11271008, 61072147)
文摘In this paper,we consider the wick-type Kd V-Burgers equation with variable coefficients. By using Tanh method with the aid of Hermite transformation, we deduce the exact solutions which include hyperbolic-exponential, trigonometric-exponential and exponential function solutions for the considered equation.
文摘In this paper, coupled nonlinear Schr<span style="white-space:nowrap;">ö</span>dinger equations with variable coefficients are studied, which can be used to describe the interaction among the modes in nonlinear optics and Bose-Einstein condensation. Some novel bright-dark solitons and dark-dark solitons are obtained by modified Sine-Gordon equation method. Moreover, some figures are provided to illustrate how the soliton solutions propagation is determined by the different values of the variable group velocity dispersion terms, which can be used to model various phenomena.
基金Project supported by the National Natural Science Foundation of China(Nos.11032006,11072094,and 11121202)the Ph.D.Program Foundation of Ministry of Education of China(No.20100211110022)+2 种基金the National Key Project of Magneto-Constrained Fusion Energy Development Program(No.2013GB110002)the Fundamental Research Funds for the Central Universities(Nos.lzujbky-2012-202 and lzujbky-2013-1)the Scholarship Award for Excellent Doctoral Student Granted by Lanzhou University
文摘General exact solutions in terms of wavelet expansion are obtained for multiterm time-fractional difusion-wave equations with Robin type boundary conditions. By proposing a new method of integral transform for solving boundary value problems, such fractional partial diferential equations are converted into time-fractional ordinary diferential equations, which are further reduced to algebraic equations by using the Laplace transform. Then, with a wavelet-based exact formula of Laplace inversion, the resulting exact solutions in the Laplace transform domain are reversed to the time-space domain. Three examples of wave-difusion problems are given to validate the proposed analytical method.
基金Project supported by the Earthquake Administration Foundation for Seismological Researches of China(No.200808022)the National Natural Science Foundation of China(Nos.50778163 and 50708095)the National Basic Research Program of China(No.2007CB714200)
文摘Based on the Biot theory of porous media,the exact solutions to onedimensional transient response of incompressible saturated single-layer porous media under four types of boundary conditions are developed.In the procedure,a relation between the solid displacement u and the relative displacement w is derived,and the well-posed initial conditions and boundary conditions are proposed.The derivation of the solution for one type of boundary condition is then illustrated in detail.The exact solutions for the other three types of boundary conditions are given directly.The propagation of the compressional wave is investigated through numerical examples.It is verified that only one type of compressional wave exists in the incompressible saturated porous media.
文摘The two coupled governing differential equations for the out-of-plane vibrations of non-uniform beams with variable curvature are derived via the Hamilton’s principle.These equations are expressed in terms of flexural and torsional displacements simultaneously.In this study,the analytical method is proposed.Firstly,two physical parameters are introduced to simplify the analysis.One derives the explicit relations between the flexural and the torsional displacements which can also be used to reduce the difficulty in experimental measurements.Based on the relation,the two governing characteristic differential equations with variable coefficients can be uncoupled into a sixth-order ordinary differential equation in terms of the flexural displacement only.When the material and geometric properties of the beam are in arbitrary polynomial forms,the exact solutions with regard to the outof-plane vibrations of non-uniform beams with variable curvature can be obtained by the recurrence formula.In addition,the mode transition mechanism is revealed and the influence of several parameters on the vibration of the non-uniform beam with variable curvature is explored.
基金Project supported by the National Natural Science Foundation of China (Nos. 10735030and 40775069)the Natural Science Foundation of Guangdong Province of China(No. 10452840301004616)the Scientific Research Foundation for the Doctors of University of Electronic Science and Technology of China Zhongshan Institute (No. 408YKQ09)
文摘The Painlev'e integrability and exact solutions to a coupled nonlinear Schr¨odinger (CNLS) equation applied in atmospheric dynamics are discussed.Some parametric restrictions of the CNLS equation are given to pass the Painlev'e test.Twenty periodic cnoidal wave solutions are obtained by applying the rational expansions of fundamental Jacobi elliptic functions.The exact solutions to the CNLS equation are used to explain the generation and propagation of atmospheric gravity waves.
基金Project supported by the Ministry of Minority Affairs through UGC,Government of India(No.F1-17.1/2010/MANF-CHR-ORI-1839)the Industrial Consultancy,IIT Kharagpur(No.IIT/SRIC/ISIRD/2013-14)
文摘In the present paper, Lie group symmetry method is used to obtain some exact solutions for a hyperbolic system of partial differential equations(PDEs), which governs an isothermal no-slip drift-flux model for multiphase flow problem. Those symmetries are used for the governing system of equations to obtain infinitesimal transformations, which consequently reduces the governing system of PDEs to a system of ODEs.Further, the solutions of the system of ODEs which in turn produces some exact solutions for the PDEs are presented. Finally, the evolutionary behavior of weak discontinuity is discussed.
文摘In this paper, a sufficient and necessary condition is presented for existence of a class of exact solutions to N-dimensional incompressible magnetohydrodynamic(MHD)equations. Such solutions can be explicitly expressed by appropriate formulae. Once the required matrices are chosen, solutions to the MHD equations are directly constructed.
基金the National Key Research and Development Program of China(Grant No.2016YFA0300600)the National Natural Science Foundation of China(Grant No.11974413)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000).
文摘We study the one-dimensional general non-Hermitian models with asymmetric long-range hopping and explore how to analytically solve the systems under some specific boundary conditions.Although the introduction of long-range hopping terms prevents us from finding analytical solutions for arbitrary boundary parameters,we identify the existence of exact solutions when the boundary parameters fulfill some constraint relations,which give the specific boundary conditions.Our analytical results show that the wave functions take simple forms and are independent of hopping range,while the eigenvalue spectra display rich model-dependent structures.Particularly,we find the existence of a special point coined as pseudo-periodic boundary condition,for which the eigenvalues are the same as those of the periodical system when the hopping parameters fulfill certain conditions,whereas the eigenstates display the non-Hermitian skin effect.
基金Project supported by the National Natural Science Foundation of China (Grant No.70971079)the Science Foundation of the Educational Department of Shandong Province of China (Grant No.J07YH01)
文摘In this paper,the Painlev'e properties of the modified C-KdV equation are verified by using the W-K algorithm.Then some exact soliton solutions are obtained by applying the standard truncated expansion method and the nonstandard truncated expansion method with the help of Maple software,respectively.
基金Project supported by the Xinjiang Natural Science Foundation of China(Grant No.2016D01C003)
文摘An exact solution of a single impurity model is hard to derive since it breaks translation invariance symmetry. We present the exact solution of the spin-1/2 transverse Ising chain imbedded by a spin-1 impurity. Using the hole decomposition scheme, we exactly solve the spin-1 impurity in two subspaces which are generated by a conserved hole operator.The impurity enlarges the energy deformation of the ground state above a pure transverse Ising system without impurity.The specific heat coefficient shows a small anomaly at low temperature for finite size. This indicates that the impurity can tune the ground state from a magnetic impurity space to a non-magnetic impurity space, which only exists for spin-1impurity comparing with spin-1/2 impurity and a pure transverse Ising chain without impurity. These behaviors essentially come from adding impurity freedom, which induces a competition between hole and fermion excitation depending on the coupling strength with its neighbor and the single-ion anisotropy.
文摘Based on the generalized Riccati relation,an algebraic method to construct a series of exact solutionsto nonlinear evolution equations is proposed.Being concise and straightforward,the method is applied to Maccari'ssystem,and some exact solutions of the system are obtained.The method is of important significance in exploring exactsolutions for other nonlinear evolution equations.
基金This work is supported by the National Natural Science Foundation of China(Nos.11672069,11702059,11232003,11672062)The Ph.D.Programs Foundation of Ministry of Education of China(No.20130041110050)+3 种基金the Research Startup Project Plan for Liaoning Doctors(No.20141119)the Fundamental Research Funds for the Central Universities(20000101)the Natural Science Foundation of Liaoning Province(No.20170540199)111 Project(B08014).
文摘In this paper,a nonlinear wave equation with variable coefficients is studied,interestingly,this equation can be used to describe the travelling waves propagating along the circular rod composed of a general compressible hyperelastic material with variable cross-sections and variable material densities.With the aid of Lou’s direct method1,the nonlinear wave equation with variable coefficients is reduced and two sets of symmetry transformations and exact solutions of the nonlinear wave equation are obtained.The corresponding numerical examples of exact solutions are presented by using different coefficients.Particularly,while the variable coefficients are taken as some special constants,the nonlinear wave equation with variable coefficients reduces to the one with constant coefficients,which can be used to describe the propagation of the travelling waves in general cylindrical rods composed of generally hyperelastic materials.Using the same method to solve the nonlinear wave equation,the validity and rationality of this method are verified.
文摘In this paper, the invariant subspaces of the generalized strongly dispersive DGH equation are given, and the exact solutions of the strongly dispersive DGH equation are obtained. Firstly, transform nonlinear partial differential Equation (PDE) into ordinary differential Equation (ODE) systems by using the invariant subspace method. Secondly, combining with the dynamical system method, we use the invariant subspaces which have been obtained to construct the exact solutions of the equation. In the end, the figures of the exact solutions are given.
文摘In this paper, we investigate an integrable high order nonlocal coupled Ablowitz-Kaup-Newell-Segur (AKNS) system for the first time. With the aid of Lax pair of this nonlocal system, Darboux transformation (DT) and new soliton-like solutions are obtained. Different from local equations, Darboux transformation of nonlocal systems needs to meet certain conditions. In this article, under the condition of symmetry reduction, the components of Darboux transformation need to satisfy <img src="Edit_6aa5df34-2f85-4c91-a185-17195a7f82ee.bmp" alt="" />. In order to study the dynamic information of the solutions, the images of the solutions are given.
文摘The current work aims to present abundant families of the exact solutions of Mikhailov-Novikov-Wang equation via three different techniques.The adopted methods are generalized Kudryashov method(GKM),exponential rational function method(ERFM),and modified extended tanh-function method(METFM).Some plots of some presented new solutions are represented to exhibit wave characteristics.All results in this work are essential to understand the physical meaning and behavior of the investigated equation that sheds light on the importance of investigating various nonlinear wave phenomena in ocean engineering and physics.This equation provides new insights to understand the relationship between the integrability and water waves’phenomena.
文摘In this study, we will introduce the modified (G'/G<sup>2</sup>)-expansion method to explore some of the exact traveling wave solutions of some nonlinear partial differential equations namely, Phi-4 equation, Joseph-Egri (TRLW) equation, and Calogro-Degasperis (CD) equation. As a result, we have obtained solutions for the equations expressed in terms of trigonometric, hyperbolic and rational functions. Moreover, some selected solutions are plotted using some specific values for the parameters.