【摘要】 和数学变分原理的意义不同,物理变分原理是物理界的客观规律,是基本规律.热力学定律是能量守恒定律,指任一自然过程的能量总是守恒的;但同时又是物理变分原理,指从一种状态变化到另一无限接近的状态,在所有可能的稳定过程中,真实过程的能量取极小值,因而又是动量定律.特别是对于存在迁移变分的过程和偏离平衡态不大的不可逆过程,物理变分原理特别有效,可以用来推求连续介质的控制方程,且尚未完全研究透彻.本文对这一原理及其在电磁介质中的某些应用进行了一些研究.更多还原

【Abstract】 In contrast to the mathematical variational principle the physical variational principle is a basic objective physical law.The first law of thermodynamics is an energy conservation law,which means that in any natural process the energy of the system is conservation.But this law is also a physical variational principle which means that the energy takes the minimum value in a stationary process for all possible process from a state to other neighboring state.The physical variational principle is a momentum law and can be used to derive the governing equation fou the continuum media.Especially it is very valid for the non-equilibrium process which is slightly deviated from the reversible process and the further study is needed.In this paper the application in the electromagnetic medium is carried out.更多还原