共查询到18条相似文献,搜索用时 62 毫秒
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研究非完整力学系统的形式不变性导致的非Noether守恒量——Hojman守恒量. 在时间不变的特殊无限小变换下,给出非完整系统形式不变性的确定方程、约束限制方程和附加限制方程,提出并定义弱(强)形式不变性的概念. 研究特殊形式不变性导致特殊Lie对称性的条件,由系统的特殊形式不变性,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. 给出两个经典例子说明结果的应用.
关键词:
分析力学
非完整系统
形式不变性
非Noether守恒量
Hojman守恒量 相似文献
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本文研究Lagrange系统的Lie-形式不变性。给出系统Lie-形式不变性的定义和判据。导出由Lie-形式不变性导致的Hojman守恒量和一类新型守恒量。最后,举例说明结果的应用. 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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Hojman conserved quantity deduced by weak Noether symmetry for Lagrange systems 总被引:1,自引:0,他引:1 下载免费PDF全文
This paper studies the Hojman conserved quantity, a non-Noether conserved quantity, deduced by special weak Noether symmetry for Lagrange systems. Under special infinitesimal transformations in which the time is not variable, its criterion is given and a method of how to seek the Hojman conserved quantity is presented. A Hojman conserved quantity can be found by using the special weak Noether symmetry. 相似文献
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Non-Noether symmetries and conserved quantities of the Lagrange mechano-electrical systems 总被引:2,自引:0,他引:2 下载免费PDF全文
This paper focuses on studying non-Noether symmetries and conserved quantities of Lagrange mechano-electrical dynamical systems. Based on the relationships between the motion and Lagrangian, we present conservation laws on non-Noether symmetries for Lagrange mechano-electrical dynamical systems. A criterion is obtained on which non-Noether symmetry leads to Noether symmetry of the systems. The work also gives connections between the non-Noether symmetries and Lie point symmetries, and further obtains Lie invariants to form a complete set of non-Noether conserved quantity. Finally, an example is discussed to illustrate these results. 相似文献
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研究单面完整约束系统的对称性与守恒量.给出单面完整约束系统Lie对称性的定义,得到了由依赖于速度的一般Lie对称性直接导致的Lutzky守恒量,并给出了它的若干特例:有多余坐标的完整约束系统、非保守力学系统、Lagrange系统的Lutzky守恒量.并举例说明结果的应用.
关键词:
分析力学
单面约束
Lie对称性
Lutzky守恒量 相似文献
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研究一般完整系统Mei对称性的共邢不变性与守恒量.引入无限小单参数变换群及其生成元向量,定义一般完整系统动力学方程的Mei对称性共形不变性,借助Euler算子导出Mei对称性共形不变性的相关条件,给出其确定方程.讨论共形不变性与Noether对称性、Lie对称性以及Mei对称性之间的关系.利用规范函数满足的结构方程得到系统相应的守恒量.举例说明结果的应用.
关键词:
一般完整系统
Mei对称性
共形不变性
守恒量 相似文献
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研究Lagrange系统的Mei对称性直接导致的一种守恒量. 给出系统的Mei对称性的定义和判据方程, 得到系统Mei对称性直接导致的一种守恒量的条件和形式,并举例说明结果的应用.
关键词:
Lagrange系统
Mei对称性
守恒量 相似文献
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Conformal invariance and conserved quantity of third-order Lagrange equations for non-conserved mechanical systems 下载免费PDF全文
This paper studies conformal invariance and conserved
quantity of third-order Lagrange equations for non-conserved
mechanical systems. Third-order Lagrange equations, the definition
and a determining equation of conformal invariance of the system are
presented. The conformal factor expression is deduced from conformal
invariance and Lie symmetry. The necessary and sufficient condition
that conformal invariance of the system would have Lie symmetry under
single-parameter infinitesimal transformations is obtained. The
corresponding conserved quantity of conformal invariance is derived
with the aid of a structure equation. Lastly, an example is given to
illustrate the application of the results. 相似文献
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Conformal invariance and conserved quantities of non-conservative Lagrange systems by point transformations 下载免费PDF全文
This paper studies the conformal invariance by infinitesimal point
transformations of non-conservative Lagrange systems. It gives the
necessary and sufficient conditions of conformal invariance by the
action of infinitesimal point transformations being Lie symmetric
simultaneously. Then the Noether conserved quantities of conformal
invariance are obtained. Finally an illustrative example is given to
verify the results. 相似文献