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1.
非Четаев型非完整系统的Lie对称性与守恒量   总被引:29,自引:0,他引:29  
研究非Четаев型非完整系统的Lie对称性.首先利用微分方程在无限小变换下的不变性建立Lie对称所满足的确定方程和限制方程,给出结构方程并求出守恒量;其次研究上述问题的逆问题:根据已知积分求相应的Lie对称性;最后举例说明结果的应用.  相似文献   

2.
For the holonomic and non-holonomic Hamiltonian systems in phase space, the definitions and criterions of the form invariance of both Hamilton and generalized Hamilton canonical equations are given. The relations among the form invariance, Noether symmetry and Lie symmetry are studied. Two examples are given to illustrate these results.  相似文献   

3.
经典约束力学系统对称性与守恒量研究进展   总被引:2,自引:0,他引:2  
梅凤翔 《力学进展》2009,39(1):37-43
介绍有关经典约束力学系统对称性与守恒量研究的近代发展.提出经典力学发展的5个阶段以及待研究的3个问题. 介绍Noether对称性,Lie对称性, 形式不变性, Lagrange对称性,共形不变性以及由它们导致的守恒量, 并提出若干问题.   相似文献   

4.
具有可积微分约束的力学系统的Lie对称性   总被引:7,自引:0,他引:7  
梅凤翔 《力学学报》2000,32(4):466-472
研究具有可积微分约束的力学系统的Lie对称性与守恒量。采用两种方法:一是用不可积微分约束系统的方法;另一是用积分后降阶系统的方法,研究两种方法之间的关系。  相似文献   

5.
葛伟宽  张毅 《力学季刊》2004,25(4):573-576
研究完整力学系统由Noether对称性导致的Hojman守恒量.列写系统的运动微分方程;在时间不变的特殊无限小变换下,研究系统的Noether对称性与Lie对称性,给出Noether对称性为Lie对称性的条件;将Hojman定理推广至变质量系统,并举例说明结果的应用.  相似文献   

6.
Hamilton系统的一类新型守恒律   总被引:1,自引:0,他引:1  
张毅 《力学季刊》2002,23(3):392-396
研究Hamilton系统的Lie对称性与守恒律。根据微分方程在无限小群变换下的不变性理论,建立了Hamilton系统仅依赖于正则变量的无限小群变换的Lie对称变换,给出了Lie对称性的确定方程,并直接由系统的Lie对称性得到了系统的一类新型定恒律。文末,举例说明结果的应用。  相似文献   

7.
关于力学系统的对称性与不变量   总被引:64,自引:2,他引:64  
赵跃宇  梅凤翔 《力学进展》1993,23(3):360-372
本文综述了近10年来关于力学系统的对称性和不变量的研究所提出的新概念、新理论,主要包括经典Noether对称性的微分几何描述、高阶Noether对称性、Lie对称性,拟对称性和伴随对称性以及与之相应的不变量,关于非保守系统的高阶Noether对称性和Lie对称性的结果属首次公布。   相似文献   

8.
吴润衡  邹杰涛 《力学季刊》2000,21(3):331-336
本文研究质量非完整系统的Lie对称性逆问题:根据已知积分求相应的Lie对称性,具体研究了受Chetaev型和非Chetaev型非完整约束的变质量系统的Lie对称性逆问题。首先,根据Lie对称所满足的确定方程和限制方程,给出Lie对称的结构方程和相应的守恒量及其表达式;其次,由已知守恒量求出相应的Noether对称性;最后,根据Noether对称性求出相应的Lie对称性。  相似文献   

9.
邹杰涛  吴润衡 《力学季刊》2001,22(3):369-373
研究非完整系统的Lie对称性与Noether对称性及其间的关系,具体研究了Chetaev型变量质量非完整系统和非Chetaev型非完整系统的Lie对称性与Noether对称性。给出Lie对称性导致Noether对称性及Noether对称性导致Lie对称性的条件。  相似文献   

10.
The Noether symmetries and conserved quantities for Birkhoffian systems with time delay are proposed and studied. First, the Pfaff–Birkhoff principle with time delay is proposed, and Birkhoff’s equations with time delay are obtained. Second, based on the invariance of the Pfaff action with time delay under a group of infinitesimal transformations, the Noether symmetric transformations and the Noether quasisymmetric transformations of the system are defined, and the criteria of the Noether symmetries are established. Finally, the relationship between the symmetries and the conserved quantities are studied, and the Noether theorems for Birkhoffian systems with time delay are established. Some examples are given to illustrate the application of the results.  相似文献   

11.
Lie symmetries and conserved quantities of rotational relativistic systems   总被引:4,自引:0,他引:4  
IntroductionIn1979,R.BengtssonandS.Franendorfaccuratlymeasuredthemaximumvaluesofthespinvelocityof14kindsofnucleons,andtheresultsshowedthatthemaximumvalueofthespinvelocityofonenucleonwasdifferenttothoseoftheothers[1].Withthedevelopmentofscienceandtechnology,…  相似文献   

12.
The Lie symmetries and the conserved quantities of the second-order nonholonomic mechanical system are studied. Firstly, by using the invariance of the differential equation of motion under the infinitesimal transformations, the determining equations and the restriction equations of the Lie symmetries of the system are established, and the structure equation and the conservative quantities of the Lie symmetries are obtained. Secondly , the inverse problems of the Lie symmetries are studied . Finally , an example is given to illustrate the application of the result.  相似文献   

13.
A FORM INVARIANCE OF CONSTRAINED BIRKHOFFIAN SYSTEM   总被引:2,自引:0,他引:2  
IntroductionThestudyofthedynamicsofBirkhoffiansystemisanactivebranchinthemodernclassicalmathematicsandamoderndevelopingdirectioninmathematicphysics ,andcanbeappliedtoquantummechanics,statisticalmechanics ,biologicphysics,mechanicsofspaceflightandsomefie…  相似文献   

14.
IntroductionIn 1 92 7,theAmericanmathematicianG .D .BirkhoffmadeprimaryresearchesonBirkhoffiandynamics[1].In 1 983,theAmericanphysicistR .M .SantillistudiedthetransformationtheoryofBirkhoffequationsandgeneralizationofGalileirelativity ,andsummarizedcomprehensivelytheoriginofBirkhoffequationsandthelaterstudiesonthem[2 ].Since 1 992 ,theChinesemechanicianMeiFeng_xianganditsco_workershaveconstructedthedynamicsofBirkhoffiansystemonthebasisofRefs.[1 ,2 ] ,andgavethebasictheoreticalframe[3 - …  相似文献   

15.
IntroductionThereisacloserelationbetweenthesymmetryandtheconservedquantityinamechanicalsystem .ModernmethodstofindconservedquantityofamechanicalsystemaremainlyNoethersymmetrymethod[1]andLiesymmetrymethod[2 ].NoethersymmetryisaninvarianceoftheHamiltonactionundertheinfinitesimaltransformations.Liesymmetryisaninvarianceofthedifferentialequationsundertheinfinitesimaltransformations.Inthepasttenyears,aseriesofimportresultshavebeenobtainedonthestudyoftheNoethersymmetryandLiesymmetry[3~12 ].Thefo…  相似文献   

16.
Perturbation to Noether symmetries and adiabatic invariants of discrete nonholonomic nonconservative mechanical systems on an uniform lattice are investigated. Firstly, we review Noether symmetry and conservation laws of a nonholonomic nonconservative system. Secondly, we study continuous Noether symmetry of a discrete nonholonomic system, give the Noether symmetry criterion and theorem of discrete corresponding holonomic system and nonholonomic system. Thirdly, we study perturbation to Noether symmetry of the discrete nonholonomic nonconservative system, give the criterion of perturbation to Noether symmetry for this system, and based on the definition of adiabatic invariants, we construct the theorem under which can lead to Noether adiabatic invariants for this system, and the forms of discrete Noether adiabatic invariants are given. Finally, we give an example to illustrate our results.  相似文献   

17.
IntroductionThestudyofsymmetryandconservedquantityofmechanicalsystemisanimportanttopicinmathematics,mechanicsandphysics .ThemoderntheoriesofsymmetryandconservedquantityofmechanicalsystemincludeNoethersymmetrytheoryandLiesymmetrytheory .In 1979M .Lutzkyando…  相似文献   

18.
Lie symmetries and conserved quantities of holonomic variable mass systems   总被引:5,自引:0,他引:5  
In this paper, the Lie symmetries and the conserved quantities of the holonomic variable mass systems are studied. By using the invariance of the ordinary differential equations under the infinitesimal transformations, the determining equations and the conserved quantities are given. And an example is given to illustrate the application of the result. Foundation item: the National Natural Science Foundation of China (19572038)  相似文献   

19.
Noether conserved quantities and Mei symmetries for non-conservative Hamiltonian difference systems with irregular lattices are studied. The generalized Hamiltonian equations of the systems are given on the basis of the transformation operators in the space of discrete Hamiltonians. The Lie point transformations acting on the lattice, as well as the difference equations, and the determining equations of Mei symmetries are obtained for the systems. The discrete versions of Noether conserved quantity are constructed by the Mei symmetries. An example is presented to illustrate the results.  相似文献   

20.
张毅 《力学季刊》2016,37(2):214-224
提出并研究时间尺度上Hamilton系统的Noether对称性与守恒量问题.建立了时间尺度上Hamilton原理,导出了相应的Hamilton正则方程.基于时间尺度上Hamilton作用量在群的无限小变换下的不变性,建立了时间尺度上Hamilton系统的Noether定理.定理的证明分成两步:第一步,在时间不变的无限小变换群下给出证明;第二步,利用时间重新参数化技术得到了一般无限小变换群下的定理.给出了经典和离散两种情况下Hamilton系统的Noether守恒量.文末举例说明结果的应用.  相似文献   

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