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 共查询到20条相似文献,搜索用时 11 毫秒
1.
陈向炜  王新民  王明泉 《中国物理》2004,13(12):2003-2007
Based on the theory of symmetries and conserved quantities, the exact invariants and adiabatic invariants of a dynamical system of relative motion are studied. The perturbation to symmetries for the dynamical system of relative motion under small excitation is discussed. The concept of high-order adiabatic invariant is presented, and the form of exact invariants and adiabatic invariants as well as the conditions for their existence are given. Then the corresponding inverse problem is studied.  相似文献   

2.
陈向炜  李彦敏 《中国物理》2003,12(9):936-939
Based on the theory of symmetries and conserved quantities of the singular Lagrange system, the perturbations to the symmetries and adiabatic invariants of the singular Lagrange systems are discussed. Firstly, the concept of higher-order adiabatic invariants of the singular Lagrange system is proposed. Then, the conditions for the existence of the exact invariants and adiabatic invariants are proved, and their forms are given. Finally, an example is presented to illustrate these results.  相似文献   

3.
准坐标下完整系统的精确不变量与绝热不变量   总被引:2,自引:0,他引:2       下载免费PDF全文
陈向炜  李彦敏 《中国物理》2005,14(4):663-668
基于对称性与不变量理论,研究了准坐标下完整系统的精确不变量与绝热不变量。研究了在小扰动作用下准坐标完整系统的对称性摄动。提出了高阶绝热不变量的概念,给出了精确不变量与绝热不变量存在的形式与条件。然后研究了相应的逆问题。  相似文献   

4.
张毅 《物理学报》2002,51(11):2417-2422
研究小干扰力作用下约束哈密顿系统对称性的摄动问题.建立了非保守约束哈密顿系统的正则方程,在增广相空间中研究了系统的对称性与精确不变量.基于力学系统的高阶绝热不变量的概念,给出了系统的各阶绝热不变量的形式及存在条件,并建立了绝热不变量与对称变换之间的对应关系 关键词: 约束哈密顿系统 对称性 摄动 不变量  相似文献   

5.
We present a study of a series of eigenstates occurring in the wedge billiard which may be quantized about tori by sejiclassical adiabatic quantization, even though the underlying classical system exhibits hard chaos and strictly possesses no tori. We also show that adiabatic eigenstates should be common in many chaotic systems, especially among the lower eigenstates, and present a heuristic argument as to why this should be so.  相似文献   

6.
Birkhoff系统的一类新型绝热不变量   总被引:2,自引:0,他引:2       下载免费PDF全文
张毅 《物理学报》2006,55(8):3833-3837
研究Birkhoff系统对称性的摄动与绝热不变量.给出了未受扰Birkhoff系统的Lie对称性导致的Hojman型精确不变量.基于力学系统的高阶绝热不变量的定义,研究在小扰动作用下Birkhoff系统Lie对称性的摄动,得到了系统的一类新型绝热不变量.举例说明结果的应用. 关键词: Birkhoff系统 Lie对称性 摄动 绝热不变量  相似文献   

7.
Lagrange系统对称性的摄动与Hojman型绝热不变量   总被引:1,自引:0,他引:1       下载免费PDF全文
张毅  范存新  梅凤翔 《物理学报》2006,55(7):3237-3240
研究Lagrange系统对称性的摄动与绝热不变量.列出未受扰Lagrange系统的Lie对称性导致的Hojman守恒量;基于力学系统的高阶绝热不变量的定义,研究在小扰动作用下Lagrange系统Lie对称性的摄动,得到了系统的一类Hojman形式的绝热不变量.并举例说明结果的应用. 关键词: Lagrange系统 对称性 摄动 绝热不变量  相似文献   

8.
罗绍凯  陈向炜  郭永新 《中国物理》2007,16(11):3176-3181
Based on the invariance of differential equations under infinitesimal transformations of group, Lie symmetries, exact invariants, perturbation to the symmetries and adiabatic invariants in form of non-Noether for a Lagrange system are presented. Firstly, the exact invariants of generalized Hojman type led directly by Lie symmetries for a Lagrange system without perturbations are given. Then, on the basis of the concepts of Lie symmetries and higher order adiabatic invariants of a mechanical system, the perturbation of Lie symmetries for the system with the action of small disturbance is investigated, the adiabatic invariants of generalized Hojman type for the system are directly obtained, the conditions for existence of the adiabatic invariants and their forms are proved. Finally an example is presented to illustrate these results.  相似文献   

9.
丁宁  方建会 《中国物理 B》2008,17(5):1550-1553
Based on the concept of adiabatic invariant, this paper studies the perturbation to Mei symmetry and adiabatic invariants for Hamilton systems. The exact invariants of Mei symmetry for the system without perturbation are given. The perturbation to Mei symmetry is discussed and the adiabatic invariants induced from the perturbation to Mei symmetry of the system are obtained.  相似文献   

10.
乔永芬  李仁杰  孙丹娜 《中国物理》2005,14(10):1919-1925
The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system are studied. The relations between the invariants and the symmetries of the system are established. Based on the concept of higher-order adiabatic invariant of a mechanical system under the action of a small perturbation, the forms of the exact invariants and adiabatic invariants and the conditions for their existence are proved. Finally, the inverse problem of the perturbation to symmetries of the system is studied and an example is also given to illustrate the application of the results.  相似文献   

11.
事件空间中完整系统的Lie对称性与绝热不变量   总被引:3,自引:0,他引:3       下载免费PDF全文
张毅 《物理学报》2007,56(6):3054-3059
研究事件空间中完整力学系统Lie对称性的摄动与绝热不变量.基于力学系统的高阶绝热不变量的概念,研究在小扰动作用下系统Lie对称性的摄动,得到了事件空间中完整力学系统的一类Hojman形式的高阶绝热不变量,给出了绝热不变量存在的条件及形式.并举例说明结果的应用. 关键词: 事件空间 对称性 摄动 绝热不变量  相似文献   

12.
陈向炜  李彦敏 《中国物理》2003,12(12):1349-1353
Based on the theory of symmetries and conserved quantities, the perturbation to the symmetries and adiabatic invariants of a type of nonholonomic singular system are discussed. Firstly, the concept of higher order adiabatic invariants of the system is proposed. Secondly, the conditions for existence of the exact invariants and adiabatic invariants are proved, and their forms are given. Thirdly, we study the inverse problems of the perturbation to symmetries of the system. An example is presented to illustrate these results.  相似文献   

13.
张毅 《中国物理》2006,15(9):1935-1940
The perturbations to symmetries and adiabatic invariants for nonconservative systems of generalized classical mechanics are studied. The exact invariant in the form of Hojman from a particular Lie symmetry for an undisturbed system of generalized mechanics is given. Based on the concept of high-order adiabatic invariant in generalized mechanics, the perturbation to Lie symmetry for the system under the action of small disturbance is investigated, and a new adiabatic invariant for the nonconservative system of generalized classical mechanics is obtained, which can be called the Hojman adiabatic invariant. An example is also given to illustrate the application of the results.  相似文献   

14.
For a perturbed mechanical system in phase space, considering d/dt in the structure equation and process of proof including infinitesimal parameter ε obviously, this paper studies the perturbation to Mei symmetry and adiabatic invariants. Firstly, the exact invariant induced directly from the Mei symmetry of the system without perturbation is given. Secondly, based on the concept of high-order adiabatic invariant, the determining equations of the perturbation to Mei symmetry are established, the condition of existence of the Mei adiabatic invariant led by the perturbation to Mei symmetry is obtained, and its form is presented. Lastly, an example is given to illustrate the application of the results.  相似文献   

15.
张毅 《物理学报》2007,56(4):1855-1859
研究相空间中离散力学系统对称性的摄动与绝热不变量.列出相空间中未受扰离散力学系统的特殊Lie对称性导致的Hojman型精确不变量.基于相空间中力学系统的高阶绝热不变量的定义,研究在小扰动作用下系统Lie对称性的摄动,得到了相空间中离散力学系统的一类新的绝热不变量——Hojman型绝热不变量.举例说明结果的应用. 关键词: 相空间 Lie对称性 摄动 绝热不变量  相似文献   

16.
丁宁  方建会  陈相霞 《中国物理 B》2008,17(6):1967-1971
The perturbation to Lie symmetry and another type of Hojman adiabatic invariants induced from the perturbation to Lie symmetry for Birkhoffian systems are studied. The exact invariants of Lie symmetry for the system without perturbation are given. Based on the concept of adiabatic invariant, the perturbation to Lie symmetry is discussed and another new type of Hojman adiabatic invariants that have the different form from that in [Acta Phys. Sin. 55 3833] for the perturbed system are obtained.  相似文献   

17.
陈菊  张毅 《物理学报》2014,63(10):104501-104501
基于El-Nabulsi动力学模型,研究了小扰动作用下Birkhoff系统Noether对称性的摄动与绝热不变量问题.首先,将El-Nabulsi提出的在分数阶微积分框架下基于Riemann-Liouville分数阶积分的非保守系统动力学模型拓展到Birkhoff系统,建立El-Nabulsi-Birkhoff方程;其次,基于在无限小变换下El-Nabulsi-Pfaff作用量的不变性,给出Noether准对称性的定义和判据,得到了Noether对称性导致的精确不变量;再次,引入力学系统的绝热不变量概念,研究El-Nabulsi动力学模型下受小扰动作用的Birkhoff系统Noether对称性的摄动与绝热不变量之间的关系,得到了对称性摄动导致的绝热不变量的条件及其形式.作为特例,给出了El-Nabulsi动力学模型下相空间中非保守系统和经典Birkhoff系统的Noether对称性的摄动与绝热不变量.以著名的Hojman-Urrutia问题为例,研究其在El-Nabulsi动力学模型下的Noether对称性,得到了相应的精确不变量和绝热不变量.  相似文献   

18.
张克军  方建会  李燕 《中国物理 B》2011,20(5):54501-054501
Based on the concept of discrete adiabatic invariant,this paper studies the perturbation to Mei symmetry and Mei adiabatic invariants of the discrete generalized Birkhoffian system.The discrete Mei exact invariant induced from the Mei symmetry of the system without perturbation is given.The criterion of the perturbation to Mei symmetry is established and the discrete Mei adiabatic invariant induced from the perturbation to Mei symmetry is obtained.Meanwhile,an example is discussed to illustrate the application of the results.  相似文献   

19.
20.
荆宏星  李元成  夏丽莉 《物理学报》2007,56(6):3043-3049
研究变质量单面完整约束系统Lie对称性的摄动与广义Hojman型绝热不变量.首先通过一般无限小变换下的Lie对称性得到广义Hojman型的守恒量;然后基于力学系统高阶绝热不变量的定义,研究小扰动作用下系统Lie对称性的摄动,得到系统广义Hojman型绝热不变量;最后举例说明结果的应用. 关键词: 变质量 单面完整约束 对称性 摄动 绝热不变量  相似文献   

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