共查询到16条相似文献,搜索用时 126 毫秒
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研究非保守力和非完整约束对Lagrange系统的Noether对称性的影响. Lagrange系统受到非保守力或非完整约束作用时,系统的Noether对称性和守恒量都会发生变化. 原有的一些Noether对称性消失了,一些新的Noether对称性产生了,在一定条件下,一些Noether对称性仍保持不变. 分别给出系统的Noether对称性以及守恒量保持不变的条件,并举例说明结果的应用.
关键词:
Lagrange系统
非保守力
非完整约束
Noether对称性 相似文献
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研究变质量Chetaev型非完整系统Appell方程的Mei对称性和Mei守恒量.建立变质量Chetaev型非完整系统的Appell方程和系统的运动微分方程; 给出函数沿系统运动轨道曲线对时间t全导数的表示式,并在群的无限小变换下,给出变质量Chetaev型非完整系统Appell方程Mei对称性的定义和判据;得到用Appell函数表示的Mei对称性的结构方程和Mei守恒量的表达式,并举例说明结果的应用.
关键词:
变质量
非完整系统
Appell方程
Mei守恒量 相似文献
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在群的无限小变化下, 研究奇异变质量单面非完整系统Nielsen方程的Noether-Lie对称性. 建立系统运动微分方程的Nielsen形式, 给出系统Nielsen方程的Noether-Lie对称性的定义、判据和命题, 得到系统Nielsen 方程的Noether-Lie对称性所导致的Noether守恒量和广义Hojman守恒量. 最后给出说明性算例说明结果的应用.
关键词:
奇异变质量系统
单面非完整约束
Nielsen方程
Noether-Lie对称性 相似文献
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利用时间不变的无限小变换下的Lie对称性,研究变质量完整力学系统的一类新的守恒量.给出系统的运动微分方程,研究时间不变的无限小变换下的Lie对称性确定方程,将Hojman定理推广并应用于这类系统
关键词:
变质量系统
完整约束
确定方程
非Noether守恒量 相似文献
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HOU Qi-Bao LI Yuan-Cheng XiA Li-Li WANG Jing 《理论物理通讯》2007,48(4):619-622
The unified symmetry of a nonholonomic system of non-Chetaev's type with variable mass in event space is studied. The differential equations of motion of the system are given. Then the definition and the criterion of the unified symmetry for the system are obtained. Finally, the Noether conserved quantity, the Hojman conserved quantity, and a new type of conserved quantity are deduced from the unified symmetry of the nonholonomic system of non-Chetaev's type with variable mass in event space at one time. An example is given to illustrate the application of the results. 相似文献
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This paper studies the symmetry of Lagrangians of
nonholonomic systems of non-Chetaev's type. First, the definition
and the criterion of the symmetry of the system are given. Secondly,
it obtains the condition under which there exists a conserved
quantity and the form of the conserved quantity. Finally, an example
is shown to illustrate the application of the result. 相似文献
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Based on the total time
derivative along the trajectory of the system
the definition and the criterion for a unified symmetry of nonholonomic
mechanical system with variable mass are presented in this paper. A new
conserved quantity, as
well as the Noether conserved quantity and the Hojman conserved quantity,
deduced from the unified symmetry, are also obtained. An example is given to
illustrate the application of the results. 相似文献
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研究非完整力学系统的Noether对称性导致的非Noether守恒量——Hojman守恒量. 在时间不变的特殊无限小变换下,给出系统的特殊Noether对称性与守恒量,并给出特殊Noether对称性导致特殊Lie对称性的条件. 由系统的特殊Noether对称性,得到相应完整系统的Hojman守恒量以及非完整系统的弱Hojman守恒量和强Hojman守恒量. 给出一个例子说明本结果的应用
关键词:
分析力学
非完整系统
Noether对称性
非Noether守恒量
Hojman守恒量 相似文献
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In this paper, we have studied the unified symmetry of a nonholonomic
mechanical system in phase space. The definition and the criterion
of a unified symmetry of the nonholonomic mechanical system in
phase space are given under general infinitesimal transformations
of groups in which time is variable. The Noether conserved
quantity, the generalized Hojman conserved quantity and the Mei
conserved quantity are obtained from the unified symmetry. 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