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Non-Noether conserved quantity constructed by using form invariance for Birkhoffian system 总被引:6,自引:0,他引:6 下载免费PDF全文
Based on the invariance of Birkhoffian equations under the infinitesimal transformations of groups, the definition and the criterion of a form invariance for a Birkhoffian system are established. The condition under which the form invariance can lead to a non-Noether conserved quantity and the form of the conserved quantity are deduced by relyingon the total time derivative along the trajectory of the equations, and two corollaries in special cases are presented. An example is finally given to illustrate the application of the results. 相似文献
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The oscillation of a delay difference equationis studied and the necessary and sufficient condition for all positive solutions of (E) to oscillate about its positive equilibrium is obtained. 相似文献
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Some nonclassical potential symmetry generators and group-invariant solutions of heat equation and wave equation were determined. It is shown that some new explicit solutions of partial differential equations in conserved form can be constructed by using the nonclassical potential symmetry generators which are derived from their adjoint system. These explicit solutions cannot be obtained by using the Lie or Lie-Backlund symmetry group generators of differential equations. 相似文献
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研究非保守Nielsen方程由形式不变性直接导致的非Noether守恒量.函数对时间的全导数采 用沿运动轨道曲线的方式,给出非保守Nielsen方程的非点的形式不变性的定义和判据,并 研究其Noether守恒量.得到形式不变性导致非Noether守恒量的条件以及守恒量的形式,并 给出三种特殊情形的推论.举例说明结果的应用.
关键词:
Nielsen方程
形式不变性
非Noether守恒量 相似文献
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By using the concept of almost periodic "sequence", that is, a real valued function on Z satisfying the Bohr almost periodic condition, sufficient conditions are obtained for the existence of almost periodic solutions of Lasota-Wazewska-type differential equations with almost periodic time dependence. 相似文献
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The new symmetries for a mathematical model of fast diffusion are determined. A new system method is given to search for new symmetries of differential equations written in a conserved form, several new symmetry generators and exact solutions are presented. 相似文献
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有多余坐标的完整系统形式不变性导致的新守恒量 总被引:2,自引:0,他引:2
研究有多余坐标的完整力学系统由形式不变性直接导出的新型守恒量。用有多余坐标的双面理想完整约束力学系统的运动微分方程和约束方程在无限小变换下的形式不变性,给出系统形式不变性的定义和判据。得到形式不变性导致守恒量的条件以及守恒量的形式,并给出三种特殊情形下的推论。举例说明结果的应用。 相似文献
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