两自由度弱非线性耦合系统的一阶近似Lie对称性与近似守恒量

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

The first order approximate Lie symmetries and approximate conserved quantities of the weak nonlinear coupled two-dimensional system

A real weak nonlinear coupled two-dimensional system is constructed first by using coupling spring with variable force constant. The first-order approximate Lie symmetries and approximate conserved quantities of the system are studied. The system possesses six first-order approximate Lie symmetries and approximate conserved quantities, of which one is an exact conserved quantity, four are trivial conserved quantities, and only one is a stable conserved quantity.
Keywords：weak nonlinear coupled two-dimensional systemapproximate Lie symmetriesapproximate conserved quantity