非平衡定态化学反应体系对细致平衡偏离的不可逆性之随机热力学量度

在随机描述的层次上,成功地构筑了非平衡定态化学反应体系对细致平衡偏离的不可逆性之随机热力学判据.基于Fokker-Planck方程建立了连续Markov过程系统的随机熵平衡方程,发现在随机态空间中随机熵的时间变率亦可分为源项和流项两部分贡献.对于化学反应体系,作为态空间源项的随机熵产生可作为偏离细致平衡不可逆性的合适度量,此泛函量的零值标志着细致平衡.进一步借助按系统广度量的Ω展开法,通过对随机力及共轭的随机流的分析揭示态空间中的随机熵产生仅源于状态对细致平衡的偏离,并主要来自非Poisson涨落的贡献,因而可作为随机热力学量去判别和量度化学反应体系对细致平衡的偏离.

A Stochastic-thermodynamic Measurement for Irreversibility Arising in Non-equilibrium Chemical Reaction Systems at Steady States Departing from the Detailed Balance

A Criterion to identify the non-equilibrium chemical reaction systems at steady states departed from the detailed balance was constructed successfully at the stochastic level. Based on the Fokker-Planck equation, we have established a stochastic entropy balance equation for the non-equilibrium systems undergoing continuous Markov processes. Along with this balance we further decompose the time evolution of the stochastic entropy into two contributions in the stochastic state space: the stochastic entropy production and the conjugate flow. Furthermore, it has turned out that the stochastic entropy production in this formalism tends to trivial if the detailed balance is satisfied. Therefore, this kind of stochastic entropy production becomes an appropriate measure for the mesoscopic irreversibility departing from the detailed balance. By means of Ω-expansion it is shown that the stochastic entropy production remains to be a stochastic thermodynamic quantity in the order of N(N is an extensive quantity characteristic of the amount of system) originated from the irreversibility departing from the detailed balance, principally coming from the contribution of the non-Poisson fluctuations.