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Integrating Factors and Conservation Laws of Herglotz Type for Birkhoffian Systems 被引量:1
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作者 WANG Wenjing ZHANG Yi 《Wuhan University Journal of Natural Sciences》 2025年第1期49-56,共8页
The method of integrating factors is used to study the conservation laws of the Herglotz type Birkhoffian systems in this paper.Firstly,the definition of the integrating factors of the Herglotz type Birkhoffian system... The method of integrating factors is used to study the conservation laws of the Herglotz type Birkhoffian systems in this paper.Firstly,the definition of the integrating factors of the Herglotz type Birkhoffian systems is given.Secondly,the relationship between the integrating factors and conservation laws is studied,and the conservation theorems of Herglotz type Birkhoff's equations and their inverse theorems are established.Thirdly,two types of generalized Killing equations for calculating integrating factors are given.Finally,as an example,a linear damped oscillator is taken.This example can be transformed into a Herglotz type Birkhoffian system.The resulting conservation theorems are used to find the conserved quantities for this example. 展开更多
关键词 Birkhoffian system Herglotz's variational principle integrating factors conservation law
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Conservation Laws and Particular Solutions for a Keller-Segel Model
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作者 Luyun Chen Jie Lou 《Advances in Pure Mathematics》 2025年第2期107-118,共12页
This work focuses on a Keller-Segel chemotaxis model, with an emphasis on its conservation laws. Through a new approach combined with the multiplier method, called the mixed method, we obtain conservation vectors that... This work focuses on a Keller-Segel chemotaxis model, with an emphasis on its conservation laws. Through a new approach combined with the multiplier method, called the mixed method, we obtain conservation vectors that are related and unrelated to symmetric information. In addition, some exact solutions with particular forms are obtained according to the method of conservation laws. These particular solutions are different from the group-invariant solutions. 展开更多
关键词 Keller-Segel Model conservation laws Mixed Method Exact Solutions
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The time-fractional(2+1)-dimensional Heisenberg ferromagnetic spin chain equation:its Lie symmetries,exact solutions and conservation laws
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作者 Jicheng Yu Yuqiang Feng 《Communications in Theoretical Physics》 2025年第5期21-30,共10页
In this paper,the Lie symmetry analysis method is applied to the(2+1)-dimensional time-fractional Heisenberg ferromagnetic spin chain equation.We obtain all the Lie symmetries admitted by the governing equation and re... In this paper,the Lie symmetry analysis method is applied to the(2+1)-dimensional time-fractional Heisenberg ferromagnetic spin chain equation.We obtain all the Lie symmetries admitted by the governing equation and reduce the corresponding(2+1)-dimensional fractional partial differential equations with the Riemann–Liouville fractional derivative to(1+1)-dimensional counterparts with the Erdélyi–Kober fractional derivative.Then,we obtain the power series solutions of the reduced equations,prove their convergence and analyze their dynamic behavior graphically.In addition,the conservation laws for all the obtained Lie symmetries are constructed using the new conservation theorem and the generalization of Noether operators. 展开更多
关键词 Lie symmetries fractional partial differential equation Heisenberg ferromagnetic spin chain equation power series solutions conservation laws
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Residual symmetry, interaction solutions, and conservation laws of the(2+1)-dimensional dispersive long-wave system 被引量:9
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作者 夏亚荣 辛祥鹏 张顺利 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第3期207-214,共8页
We explore the (2+l)-dimensional dispersive long-wave (DLW) system. From the standard truncated Painleve expansion, the Baicklund transformation (BT) and residual symmetries of this system are derived. The intr... We explore the (2+l)-dimensional dispersive long-wave (DLW) system. From the standard truncated Painleve expansion, the Baicklund transformation (BT) and residual symmetries of this system are derived. The introduction to an appropriate auxiliary dependent variable successfully localizes the residual symmetries to Lie point symmetries. In particular, it is verified that the (2+l)-dimensional DLW system is consistent Riccati expansion (CRE) solvable. If the special form of (CRE)-consistent tanh-function expansion (CTE) is taken, the soliton-cnoidal wave solutions and corresponding images can be explicitly given. Furthermore, the conservation laws of the DLW system are investigated with symmetries and Ibragimov theorem. 展开更多
关键词 residual symmetry truncated Painleve expansion interaction solutions conservation law
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MULTI-DIMENSIONAL RIEMANN PROBLEM OF SCALAR CONSERVATION LAW 被引量:11
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作者 杨小舟 《Acta Mathematica Scientia》 SCIE CSCD 1999年第2期190-200,共11页
This paper considers multi-dimensional Riemann problem in another kind of view. The author gets solution of (1.1)(1.2) in Theorem 3.4 and proves itu uniqueness. A new method of solution constructing is applied, which ... This paper considers multi-dimensional Riemann problem in another kind of view. The author gets solution of (1.1)(1.2) in Theorem 3.4 and proves itu uniqueness. A new method of solution constructing is applied, which is different from the usual self-similar transformation. The author also discusses some generalized concepts in multi-dimensional situation (such as 'convex condition', 'left value' and 'right value', etc). An example is finally given to demonstrate that rarefaction wave solution of (1.1)(1.2) is not self-similar. 展开更多
关键词 Riemann problem conservation laws implicit function
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New Exact Solutions and Conservation Laws to (3+1)-Dimensional Potential-YTSF Equation 被引量:10
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作者 ZHANG Li-Hua LIU Xi-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期487-492,共6页
Using the modified find some new exact solutions to Lie point symmetry groups and also get conservation laws, of the CK's direct method, we build the relationship between new solutions and old ones and the (3+1)-d... Using the modified find some new exact solutions to Lie point symmetry groups and also get conservation laws, of the CK's direct method, we build the relationship between new solutions and old ones and the (3+1)-dimensional potentiaial-YTSF equation. Baaed on the invariant group theory, Lie symmetries of the (3+1)-dimensional potential-YTSF equation are obtained. We equation with the given Lie symmetry. 展开更多
关键词 new exact solutions Lie point symmetry groups conservation laws (3+1)-dimensional potential-YTSF equation
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A local pseudo arc-length method for hyperbolic conservation laws 被引量:7
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作者 Xing Wang Tian-Bao Ma +1 位作者 Hui-Lan Ren Jian-Guo Ning 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第6期956-965,共10页
A local pseudo arc-length method(LPALM)for solving hyperbolic conservation laws is presented in this paper.The key idea of this method comes from the original arc-length method,through which the critical points are ... A local pseudo arc-length method(LPALM)for solving hyperbolic conservation laws is presented in this paper.The key idea of this method comes from the original arc-length method,through which the critical points are bypassed by transforming the computational space.The method is based on local changes of physical variables to choose the discontinuous stencil and introduce the pseudo arc-length parameter,and then transform the governing equations from physical space to arc-length space.In order to solve these equations in arc-length coordinate,it is necessary to combine the velocity of mesh points in the moving mesh method,and then convert the physical variable in arclength space back to physical space.Numerical examples have proved the effectiveness and generality of the new approach for linear equation,nonlinear equation and system of equations with discontinuous initial values.Non-oscillation solution can be obtained by adjusting the parameter and the mesh refinement number for problems containing both shock and rarefaction waves. 展开更多
关键词 Numerical method Local pseudo arc-length method Hyperbolic conservation laws Mesh adaptation
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Symmetry Reductions, Exact Solutions and Conservation Laws of Asymmetric Nizhnik-Novikov-Veselov Equation 被引量:5
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作者 WANG Ling DONG Zhong-Zhou LIU Xi-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第1期1-8,共8页
By applying a direct symmetry method, we get the symmetry of the asymmetric Nizhnik-Novikov-Veselov equation (ANNV). Taking the special case, we have a finite-dimensional symmetry. By using the equivalent vector of ... By applying a direct symmetry method, we get the symmetry of the asymmetric Nizhnik-Novikov-Veselov equation (ANNV). Taking the special case, we have a finite-dimensional symmetry. By using the equivalent vector of the symmetry, we construct an eight-dimensional symmetry algebra and get the optimal system of group-invariant solutions. To every case of the optimal system, we reduce the ANNV equation and obtain some solutions to the reduced equations. Furthermore, we find some new explicit solutions of the ANNV equation. At last, we give the conservation laws of the ANNV equation. 展开更多
关键词 direct symmetry method ANNV equation optimal system explicit solution conservation laws
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Integrating Factors and Conservation Laws of Generalized Birkhoff System Dynamics in Event Space 被引量:5
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作者 ZHANG Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第6期1078-1082,共5页
In this paper, the conservation laws of generalized Birkhoff system in event space are studied by using the method of integrating factors. Firstly, the generalized Pfaff-Birkhoff principle and the generalized Birkhoff... In this paper, the conservation laws of generalized Birkhoff system in event space are studied by using the method of integrating factors. Firstly, the generalized Pfaff-Birkhoff principle and the generalized Birkhoff equations are established, and the definition of the integrating factors for the system is given. Secondly, based on the concept of integrating factors, the conservation theorems and their inverse for the generalized Birkhoff system in the event space are presented in detail, and the relation between the conservation laws and the integrating factors of the system is obtained and the generalized Killing equations for the determination of the integrating factors are given. Finally, an example is given to illustrate the application of the results. 展开更多
关键词 generalized Birkhoff system dynamics conservation law event space integrating tactor
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Nonlinear Self-Adjointness, Conservation Laws and Soliton-Cnoidal Wave Interaction Solutions of(2+1)-Dimensional Modified Dispersive Water-Wave System 被引量:4
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作者 夏亚荣 辛祥鹏 张顺利 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第1期15-21,共7页
This paper mainly discusses the(2+1)-dimensional modified dispersive water-wave(MDWW) system which will be proved nonlinear self-adjointness. This property is applied to construct conservation laws corresponding to th... This paper mainly discusses the(2+1)-dimensional modified dispersive water-wave(MDWW) system which will be proved nonlinear self-adjointness. This property is applied to construct conservation laws corresponding to the symmetries of the system. Moreover, via the truncated Painlev′e analysis and consistent tanh-function expansion(CTE)method, the soliton-cnoidal periodic wave interaction solutions and corresponding images will be eventually achieved. 展开更多
关键词 MDWW system nonlinear self-adjointness conservation laws truncated Painlev′e analysis CTE method interaction solutions
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Integrating Factors and Conservation Laws for Relativistic Mechanical System 被引量:4
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作者 ZHANG Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2X期231-234,共4页
In this paper, we present a new method to construct the conservation laws for relativistic mechanical systems by finding corresponding integrating factors. First, the Lagrange equations of relativistic mechanical syst... In this paper, we present a new method to construct the conservation laws for relativistic mechanical systems by finding corresponding integrating factors. First, the Lagrange equations of relativistic mechanical systems are established, and the definition of integrating factors of the systems is given; second, the necessary conditions for the existence of conserved quantities of the relativistic mechanical systems are studied in detail, and the relation between the conservation laws and the integrating factors of the systems is obtained and the generalized Killing equations for the determination of the integrating factors are given; finally, the conservation theorem and its inverse for the systems are established, and an example is given to illustrate the application of the results. 展开更多
关键词 RELATIVITY mechanical system conservation law integrating factor Killing equation
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NEW STRUCTURES FOR NON-SELFSIMILAR SOLUTIONS OF MULTI-DIMENSIONAL CONSERVATION LAWS 被引量:4
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作者 杨小舟 魏涛 《Acta Mathematica Scientia》 SCIE CSCD 2009年第5期1182-1202,共21页
In this article, we get non-selfsimilar elementary waves of the conservation laws in another kind of view, which is different from the usual self-similar transformation. The solution has different global structure. Th... In this article, we get non-selfsimilar elementary waves of the conservation laws in another kind of view, which is different from the usual self-similar transformation. The solution has different global structure. This article is divided into three parts. The first part is introduction. In the second part, we discuss non-selfsimilar elementary waves and their interactions of a class of twodimensional conservation laws. In this case, we consider the case that the initial discontinuity is parabola with u+ 〉 0, while explicit non-selfsirnilar rarefaction wave can be obtained. In the second part, we consider the solution structure of case u+ 〈 0. The new solution structures are obtained by the interactions between different elementary waves, and will continue to interact with other states. Global solutions would be very different from the situation of one dimension. 展开更多
关键词 non-selfsimilar shock wave rarefaction wave ENVELOPE multi-dimensional conservation laws
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Conservation laws of the generalized nonlocal nonlinear Schrodinger equation 被引量:5
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作者 欧阳世根 郭旗 +1 位作者 吴立军 兰胜 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第8期2331-2337,共7页
The derivations of several conservation laws of the generalized nonlocal nonlinear Schrodinger equation are presented. These invaxiants are the number of particles, the momentum, the angular momentum and the Hamiltoni... The derivations of several conservation laws of the generalized nonlocal nonlinear Schrodinger equation are presented. These invaxiants are the number of particles, the momentum, the angular momentum and the Hamiltonian in the quantum mechanical analogy. The Lagrangian is also presented. 展开更多
关键词 nonlocal nonlinear Schrodinger equation conservation law LAGRANGIAN
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Super spectral viscosity method for nonlinear conservation laws 被引量:5
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作者 马和平 李会元 《Journal of Shanghai University(English Edition)》 CAS 2006年第1期9-14,共6页
In this paper, the super spectral viscosity (SSV) method is developed by introducing a spectrally small amount of high order regularization which is only activated on high frequencies. The resulting SSV approximatio... In this paper, the super spectral viscosity (SSV) method is developed by introducing a spectrally small amount of high order regularization which is only activated on high frequencies. The resulting SSV approximation is stable and convergent to the exact entropy solution. A Gegenbauer-Chebyshev post-processing for the SSV solution is proposed to remove the spurious oscillations at the disconti-nuities and recover accuracy from the spectral approximation. The ssv method is applied to the scahr periodic Burgers equation and the one-dimensional system of Euler equations of gas dynamics. The numerical results exhibit high accuracy and resolution to the exact entropy solution, 展开更多
关键词 conservation laws super spectral viscosity Gegenbauer-Chebyshev post-processing.
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POINTWISE CONVERGENCE RATE OF VANISHING VISCOSITY APPROXIMATIONS FOR SCALAR CONSERVATION LAWS WITH BOUNDARY 被引量:3
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作者 刘红霞 潘涛 《Acta Mathematica Scientia》 SCIE CSCD 2009年第1期111-128,共18页
This article is concerned with the pointwise error estimates for vanishing vis- cosity approximations to scalar convex conservation laws with boundary.By the weighted error function and a bootstrap extrapolation techn... This article is concerned with the pointwise error estimates for vanishing vis- cosity approximations to scalar convex conservation laws with boundary.By the weighted error function and a bootstrap extrapolation technique introduced by Tadmor-Tang,an optimal pointwise convergence rate is derived for the vanishing viscosity approximations to the initial-boundary value problem for scalar convex conservation laws,whose weak entropy solution is piecewise C 2 -smooth with interaction of elementary waves and the ... 展开更多
关键词 Scalar conservation laws with boundary vanishing viscosity approximations error estimate pointwise convergence rate transport inequality
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Conservation Laws and Soliton Solutions for Generalized Seventh Order KdV Equation 被引量:3
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作者 YAORuo-Xia XUGui-Qiong LIZhi-Bin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第4期487-492,共6页
With the assistance of the symbolic computation system Maple,rich higher order polynomial-type conservation laws and a sixth order t/x-dependent conservation law are constructed for a generalized seventh order nonline... With the assistance of the symbolic computation system Maple,rich higher order polynomial-type conservation laws and a sixth order t/x-dependent conservation law are constructed for a generalized seventh order nonlinear evolution equation by using a direct algebraic method.From the compatibility conditions that guaranteeing the existence of conserved densities,an integrable unnamed seventh order KdV-type equation is found.By introducing some nonlinear transformations,the one-,two-,and three-solition solutions as well as the solitary wave solutions are obtained. 展开更多
关键词 seventh order evolution equation conservation law soliton solution symbolic computation
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High-order maximum-principle-preserving and positivity-preserving weighted compact nonlinear schemes for hyperbolic conservation laws 被引量:3
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作者 Lingyan TANG Songhe SONG Hong ZHANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2020年第1期173-192,共20页
In this paper,the maximum-principle-preserving(MPP)and positivitypreserving(PP)flux limiting technique will be generalized to a class of high-order weighted compact nonlinear schemes(WCNSs)for scalar conservation laws... In this paper,the maximum-principle-preserving(MPP)and positivitypreserving(PP)flux limiting technique will be generalized to a class of high-order weighted compact nonlinear schemes(WCNSs)for scalar conservation laws and the compressible Euler systems in both one and two dimensions.The main idea of the present method is to rewrite the scheme in a conservative form,and then define the local limiting parameters via case-by-case discussion.Smooth test problems are presented to demonstrate that the proposed MPP/PP WCNSs incorporating a third-order Runge-Kutta method can attain the desired order of accuracy.Other test problems with strong shocks and high pressure and density ratios are also conducted to testify the performance of the schemes. 展开更多
关键词 hyperbolic conservation law maximum-principle-preserving(MPP) positivity-preserving(PP) weighted compact nonlinear scheme(WCNS) finite difference scheme
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Interaction of elementary waves of scalar conservation laws with discontinuous flux function 被引量:3
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作者 王国栋 盛万成 《Journal of Shanghai University(English Edition)》 CAS 2006年第5期381-387,共7页
In this paper, the Riemann solutions for scalar conservation laws with discontinuous flux function were constructed. The interactions of elementary waves of the conservation laws were concerned, and the numerical simu... In this paper, the Riemann solutions for scalar conservation laws with discontinuous flux function were constructed. The interactions of elementary waves of the conservation laws were concerned, and the numerical simulations were given. 展开更多
关键词 discontinuous flux function scalar conservation laws linear discontinuity shock wave rarefaction wave.
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Conservation Law Classification and Integrability of Generalized Nonlinear Second-Order Equation 被引量:2
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作者 刘汉泽 李继彬 刘磊 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第12期987-991,共5页
This paper is concerned with the generalized nonlinear second-order equation.By the direct construction method,all of the first-order multipliers of the equation are obtained,and the corresponding complete conservatio... This paper is concerned with the generalized nonlinear second-order equation.By the direct construction method,all of the first-order multipliers of the equation are obtained,and the corresponding complete conservation laws(CLs) of such equations are provided.Furthermore,the integrability of the equation is considered in terms of the conservation laws.In addition,the relationship of multipliers and symmetries of the equations is investigated. 展开更多
关键词 conservation law MULTIPLIER symmetry INTEGRABILITY direct construction method Klein-Gordonwave equation
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An extension of the modified Sawada-Kotera equation and conservation laws 被引量:3
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作者 何国亮 耿献国 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第7期37-42,共6页
Based on the modified Sawad^Kotera equation, we introduce a 3 ~ 3 matrix spectral problem with two potentials and derive a hierarchy of new nonlinear evolution equations. The second member in the hierarchy is a genera... Based on the modified Sawad^Kotera equation, we introduce a 3 ~ 3 matrix spectral problem with two potentials and derive a hierarchy of new nonlinear evolution equations. The second member in the hierarchy is a generalization of the modified Sawad-Kotera equation, by which a Lax pair of the modified Sawada-Kotera equation is obtained. With the help of the Miura transformation, explicit solutions of the Sawad-Kotera equation, the Kaup-Kupershmidt equation, and the modified Sawad-Kotera equation are given. Moreover, infinite sequences of conserved quantities of the first two nonlinear evolution equations in the hierarchy and the modified Sawada-Kotera equation are constructed with the aid of their Lax pairs. 展开更多
关键词 spectral problem explicit solutions conservation laws
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