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The Lie symmetries and Noether conserved quantities of discrete mechanical systems with variable mass 下载免费PDF全文
This paper studies the Lie symmetries and Noether conserved quantities of discrete mechanical systems with variable mass. The discrete Euler-Lagrange equation and energy evolution equation are derived by using a total variational principle. The invariance of discrete equations under infinitesimal transformation groups is defined to be Lie symmetry. The condition of obtaining the Noether conserved quantities from the Lie symmetries is also presented. An example is discussed for applications of the results. 相似文献
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Noether‘s theory of a rotational relativistic variable mass system is studied.Firstly,Jourdain‘s principle of the rotational relativistic variable mass system is given.Secondly,on the basis of the invariance of the Jourdain‘s principle under the infinitesimal transformations of groups,Noether‘s theorem and its inverse theorem of the rotational relativistic variable mass system are presented.Finally,an example is given to illustrate the application of the result. 相似文献
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在时间不变的特殊无限小变换下,研究相对论性变质量非完整可控力学系统的非Noether守恒量——Hojamn守恒量.建立了系统的运动微分方程, 给出了系统在特殊无限小变换下的形式不变性(Mei对称性)的定义和判据以及系统的形式不变性是Lie对称性的充分必要条件.得到了系统形式不变性导致非Noether守恒量的条件和具体形式.举例说明结果的应用.
关键词:
相对论
非完整可控力学系统
变质量
非Noether守恒量 相似文献
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Lie symmetry and the generalized Hojman conserved quantity of Nielsen equations for a variable mass holonomic system of relative motion 下载免费PDF全文
Lie symmetry and the generalized Hojman conserved quantity of Nielsen equations for a variable mass holonomic system of relative motion are studied. The determining equation of Lie symmetry of Nielsen equations for a variable mass holonomic system of relative motion under the infinitesimal transformations of groups is given. The expression of generalized Hojman conserved quantity deduced directly from Lie symmetry for a variable mass holonomic system of relative motion is obtained. An example is given to illustrate the application of the results. 相似文献
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研究相对论性转动变质量非完整可控力学系统的非Noether守恒量——Hojman守恒量. 建立了系统的运动微分方程, 给出了系统在特殊无限小变换下的Mei对称性(形式不变性) 和Lie对称性的定义和判据, 以及系统的Mei对称性是Lie对称性的充分必要条件. 得到了系统Mei对称性导致非Noether守恒量的条件和具体形式. 举例说明结果的应用.
关键词:
相对论性转动
可控力学系统
变质量
非Noether守恒量 相似文献
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采用变劲度系数的耦合弹簧构建一实际的两自由度弱非线性耦合系统, 用近似Lie对称性理论研究系统的一阶近似Lie对称性与近似守恒量, 得到6个一阶近似Lie对称性和一阶近似守恒量, 其中1个一阶近似守恒量实为系统的精确守恒量, 4个一阶近似守恒量为平凡的一阶近似守恒量, 只有1个一阶近似守恒量为稳定的一阶近似守恒量.
关键词:
两自由度弱非线性耦合系统
近似Lie对称性
近似守恒量 相似文献
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A set of Lie symmetrical non-Noether conserved quantity for the relativistic Hamiltonian systems 总被引:4,自引:0,他引:4 下载免费PDF全文
For the relativistic Hamiltonian system, a new type of Lie symmetrical non-Noether conserved quantities are given. On the basis of the theory of invariance of differential equations under infinitesimal transformations, and introducing special infinitesimal transformations for q_s and p_s, we construct the determining equations of Lie symmetrical transformations of the system, which only depend on the canonical variables. A set of non-Noether conserved quantities are directly obtained from the Lie symmetries of the system. An example is given to illustrate the application of the results. 相似文献
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Lie symmetries and conserved quantities of Birkhoff systems with unilateral constraints 总被引:8,自引:0,他引:8 下载免费PDF全文
In this paper we study the Lie symmetries of Birkhoff systems with unilateral constraints.We give the conditions for,and the form of,conserved quantities due to the Lie symmetries of the systems.and we also study the inverse problem of the Lie symmetries of the systems.Finally,an example is given to illustrate the application of the results. 相似文献
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FANG Jian-Hui 《理论物理通讯》2003,40(9)
The Mei symmetry and the Lie symmetry of a rotational relativistic variable masssystem are studied. Thedefinitions and criteria of the Mei symmetry and the Lie symmetry of the rotational relativistic variable mass system aregiven. The relation between the Mei symmetry and the Lie symmetry is found. The conserved quantities which the Meisymmetry and the Lie symmetry lead to are obtained. An example is given to illustrate the application of the result. 相似文献
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给出了由Birkhoff系统的Lie对称性求守恒量的一种新方法.研究了系统仅依赖于Birkhoff变量a的Lie对称变换,直接由系统的Lie对称性得到了系统的一类守恒量,并举例说明结果的应用
关键词:
分析力学
对称性
守恒量
Birkhoff系统 相似文献
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FANGJian-Hui 《理论物理通讯》2003,40(3):269-272
The Mei symmetry and the Lie symmetry of a rotational relativistic variable mass system are studied. The definitions and criteria of the Mei symmetry and the Lie symmetry of the rotational relativistic variable mass system are given. The relation between the Mei symmetry and the Lie symmetry is found. The conserved quantities which the Mei symmetry and the Lie symmetry lead to are obtained. An example is given to illustrate the application of the result. 相似文献
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A new non-Noether conserved quantity of the relativistic holonomic nonconservative systems in general Lie transformations 总被引:1,自引:0,他引:1 下载免费PDF全文
For the relativistic holonomic nonconservative system, a new Lie symmetrical non-Noether conserved quantity is given under general infinitesimal transformations of groups in which time is variable. On the basis of the theory of invariance of differential equations of motion under infinitesimal transformations for t and qs, we construct the relativistic Lie symmetrical determining equations and obtain directly a new relativistic Lie symmetrical non-Noether conserved quantity of the system, which only depend on the variables t, qs and qs. An example is given to illustrate the application of the results. 相似文献
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The symmetry of Lagrangians of a holonomic variable mass system is studied.Firstly,the differential equations of motion of the system are established.Secondly,the definition and the criterion of the symmetry of the system are presented.Thirdly,the conditions under which there exists a conserved quantity deduced by the symmetry are obtained.The form of the conserved quantity is the same as that of the constant mass Lagrange system.Finally,an example is shown to illustrate the application of the result. 相似文献