Ming B Yu
USA
Biography
Ming B Yu has graduated from Jilin University, China in 1961. He worked as a Lecturer in Zhengzhou Coal Managing College, China, and a Visiting Adjunct Lecturer in University of Georgia, USA. Currently, he is a Retiree and still active in the study of condensed matter physics: vibrations in low-dimensional lattices, etc. and statistical physics: transport equations, entropy variation, Lyapunov exponents, etc. of closed and open nonequilibrium systems. He has published more than 20 research papers in reputed journals as well as a monograph in the areas mentioned above
Abstract
A nonequilibrium system is studied in the framework of time-dependent projection operator. A macroscopic state space is introduced to describe macroscopic states of the system which is spanned by averages of a set of independent basic variables of the system. The entropy variation rate is derived as the average trace of Jacobian matrix of transport equations of the system. They are a set of nonlinear differential-integral equations. The Jacobian matrix is a sum of frequency matrix and memory matrix. Because the former is traceless, the entropy variation is contributed only by the average trace of an entropy source matrix which is a term in the memory matrix. The entropy variation and Lyapunov exponents of the system are shown determined by the non-uniformity in time and in the macro-state space of fluctuation forces associated with each basic variable of the system. This indicates a fundamental relationship between fluctuations and dissipation. It is proved that if the dynamic system defined by the transport equations is ergodic, the sum of Lyapunov exponents is equal to the time-rate of the entropy or average trace of the entropy source matrix. The study is illustrated by a one-component incompressible fluid.