机电系统的统一对称性

研究机电系统的统一对称性. 由系统的Lagrange-Maxwell方程, 给出系统的统一对称性的定义和判据, 得到了系统的统一对称性导出Noether守恒量，Hojman守恒量和Mei守恒量. 举例说明结果的应用. 关键词： 机电系统 统一对称性 守恒量     

弱非完整系统Mei对称性导致的新型精确和近似守恒量

研究弱非完整系统Lagrange方程的Mei对称性导致的一种结构方程和新型精确以及近似守恒量. 首先建立系统的Lagrange方程. 其次在群的无限小变换下, 给出了弱非完整系统及其一次近似系统Mei对称性的定义和判据, 然后得到了Mei对称性导致的新型结构方程、 新型精确和近似守恒量的表达式. 最后, 举例研究系统的精确新型守恒量和近似新型守恒量问题. 关键词： 弱非完整系统 Mei对称性 新型结构方程 新型守恒量     

一类非完整奇异系统的Lie对称性与守恒量

利用微分方程在无限小变换群下的不变性,研究一类非完整奇异系统的Lie对称性.给出Lie对称性的确定方程、限制方程、附加限制方程和结构方程,并给出守恒量的形式 关键词： 奇异系统 非完整约束 Lie对称性 守恒量     

具有非Chetaev型非完整约束的机电系统的统一对称性

研究具有非Chetaev型非完整约束的机电系统的统一对称性. 由系统的Lagrange-Maxwell方程, 给出系统的统一对称性的定义和判据, 得到了系统的统一对称性导出的Noether守恒量、Hojman守恒量和Mei守恒量. 举例说明结果的应用. 关键词： 非Chetaev型约束系统 机电系统 统一对称性 守恒量     

Chetaev型约束力学系统Appell方程的Lie对称性与守恒量

研究Chetaev型约束力学系统Appell方程的Lie对称性和Lie对称性直接导致的守恒量.分析Lagrange函数和A函数的关系;讨论Chetaev型约束力学系统Appell方程的Lie对称性导致的守恒量的一般研究方法;在群的无限小变换下,给出Appell方程Lie对称性的定义和判据;得到Lie对称性的结构方程以及Lie对称性直接导致的守恒量的表达式.举例说明结果的应用. 关键词： Appell方程 Chetaev 型约束力学系统 Lie对称性 守恒量     

相对运动动力学系统Appell方程Mei对称性导致的Mei守恒量

研究相对运动动力学系统Appell方程的Mei对称性及其直接导致的Mei守恒量.在群的无限小变换下,给出相对运动动力学系统Appell方程Mei对称性的定义和判据;得到相对运动动力学系统Appell方程Mei对称性的结构方程以及Mei对称性直接导致的Mei守恒量的表达式.举例说明结果的应用. 关键词： 相对运动动力学 Appell方程 Mei对称性 Mei守恒量     

Nielsen方程Mei对称性导致的一种新型守恒量

研究完整系统Nielsen方程Mei对称性导致的一种新型守恒量.在群的无限小变换下,由Nielsen方程Mei对称性的定义和判据,得到完整系统Nielsen方程Mei对称性导致的新型结构方程和新型守恒量.举例说明结果的应用. 关键词： Nielsen方程 Mei对称性 新型结构方程 新型守恒量     

机电系统Mei对称性导致的另一种守恒量

研究机电系统Mei对称性导致的另一种守恒量.在群的无限小变换下,给出机电系统的Mei对称性的定义和判据,得到机电系统Mei对称性导致的另一种守恒量.举例说明结果的应用. 关键词： 机电系统 Mei对称性 守恒量     

相对运动动力学系统Nielsen方程的Lie对称性与Hojman守恒量

研究相对运动动力学系统Nielsen方程的Lie对称性和Lie对称性直接导致的Hojman守恒量.在群的无限小变换下,给出相对运动动力学系统Nielsen方程Lie对称性的定义和判据;得到相对运动动力学系统Nielsen方程Lie对称性的确定方程以及Lie对称性直接导致的Hojman守恒量的表达式.举例说明结果的应用. 关键词： 相对运动动力学 Nielsen方程 Lie对称性 Hojman守恒量     

非保守力和非完整约束对Hamilton系统Lie对称性的影响

研究非保守力和非完整约束对Hamilton系统的Lie对称性和守恒量的影响.分别研究了Hamilt on系统受到非保守力和非完整约束作用时，系统的Lie对称性保持不变的条件，同时给出了 系统的结构方程和守恒量保持不变的条件.以著名的Emden方程和Appell-Hamel模型为例进行 了分析讨论. 关键词： 分析力学 Hamilton系统 非保守力 非完整约束 对称性 守恒量     

Conformal invariance and generalized Hojman conserved quantities of mechanico-electrical systems

This paper studies conformal invariance and generalized Hojman conserved quantities of mechanico-electrical systems.The definition and the determining equation of conformal invariance for mechanico-electrical systems are provided.The conformal factor expression is deduced from conformal invariance and Lie symmetry under the infinitesimal singleparameter transformation group.The generalized Hojman conserved quantities from the conformal invariance of the system are given.An example is given to illustrate the application of the result.     

Noether conserved quantities and Lie point symmetries of difference Lagrange--Maxwell equations and lattices

This paper presents a method to find Noether-type conserved quantities and Lie point symmetries for discrete mechanico-electrical dynamical systems,which leave invariant the set of solutions of the corresponding difference scheme.This approach makes it possible to devise techniques for solving the Lagrange-Maxwell equations in differences which correspond to mechanico-electrical systems,by adapting existing differential equations.In particular,it obtains a new systematic method to determine both the one-parameter Lie groups and the discrete Noether conserved quantities of Lie point symmetries for mechanico-electrical systems.As an application,it obtains the Lie point symmetries and the conserved quantities for the difference equation of a model that represents a capacitor microphone.     

Conserved Quantities and Conformal Mechanico-Electrical Systems

The conformal meehanico-electrical systems are presented by infinitesimal point transformations of time and generalized coordinates. The necessary and suflleient conditions that the eonformal meehanieo-eleetrieal systems possess Lie symmetry are given. The Noether conserved quantities of the eonformal meehanieo-eleetrieal systems are obtained from Lie symmetries.     

Symplectic-energy-first integrators of discrete mechanico-electrical dynamical systems

A discrete total variation calculus with variable time steps is presented for mechanico-electrical systems where there exist non-potential and dissipative forces. By using this discrete variation calculus, the symplectic-energy-first integrators for mechanico-electrical systems are derived. To do this, the time step adaptation is employed. The discrete variational principle and the Euler--Lagrange equation are derived for the systems. By using this discrete algorithm it is shown that mechanico-electrical systems are not symplectic and their energies are not conserved unless they are Lagrange mechanico-electrical systems. A practical example is presented to illustrate these results.     

Non-Noether symmetries and Lutzky conserved quantities for mechanico-electrical systems

We apply the non-Noether symmetry theory for mechanical systems to Lagrange–Maxwell mechanico-electrical systems. For these systems, we derive the Lutzky conserved quantities from the corresponding equations of motion, the non-conservative and the dissipative forces, and the Lagrangian. Also, a condition that characterizes when a non-Noether symmetry leads to a Noether conservation law is presented.     

A new type of conserved quantity of Mei symmetry for the motion of mechanico electrical coupling dynamical systems

We obtain a new type of conserved quantity of Mei symmetry for the motion of mechanico-electrical coupling dynamical systems under the infinitesimal transformations. A criterion of Mei symmetry for the mechanico-electrical coupling dynamical systems is given. Simultaneously, the condition of existence of the new conserved quantity of Mei symmetry for mechanico-electrical coupling dynamical systems is obtained. Finally, an example is given to illustrate the application of the results.     

Noether-Mei symmetry of a discrete mechanico-electrical system

Noether-Mei symmetry of a discrete mechanico-electrical system on a regular lattice is investigated.Firstly,the Noether symmetry of a discrete mechanico-electrical system is reviewed,and the motion equations and energy equations are derived.Secondly,the definition of Noether-Mei symmetry for the system is presented,and the criterion is derived.Thirdly,conserved quantities induced by Noether-Mei symmetry with their existence conditions are obtained.Finally,an example is discussed to illustrate the results.     

Hamilton formalism and Noether symmetry for mechanico—electrical systems with fractional derivatives

This paper presents extensions to the traditional calculus of variations for mechanico-electrical systems containing fractional derivatives.The Euler-Lagrange equations and the Hamilton formalism of the mechanico-electrical systems with fractional derivatives are established.The definition and the criteria for the fractional generalized Noether quasisymmetry are presented.Furthermore,the fractional Noether theorem and conseved quantities of the systems are obtained by virtue of the invariance of the Hamiltonian action under the infinitesimal transformations.An example is presented to illustrate the application of the results.