恒电量微扰下涂装金属体系极化电位响应式的理论推导

THE THEORETICAL DERIVATION OF POLARIZATION POTENTIAL RESPONSE EQUATION OF COATED METAL SYSTEMS UNDER COULOSTATIC PERTURBATION

恒电量微扰下的过渡过程可用一组线性微分方程组表示,求解的关键是确定其初始条件值。在恒电量扰动瞬间,有溶液电阻和忽略溶液电阻的暂态过渡过程的机制不同,因而极化电位随时间变化的函数关系也不一样。有溶液电阻时,电荷的转移和传输不能瞬间完成,需要一定的传递时间,即极化电位不会发生突变;而无溶液电阻时,依据基尔霍夫定律,在恒电量扰动瞬间,极化电位必将发生突变。同时电路受恒电量控制,无论突变瞬间或电量传递的整个过程都必须遵守电荷守恒原理。以此建立恒电量激励下过渡过程的初始条件。

Under coulostatic perturbation,the transition process may be described by a group of linear differential equations,The key of deriving the equations is to determine the value of start condition. At the moment of coulostatic perturbation,the mechanism of tran- sition process for existing solution resistance is different from that of neglecting solution resistance,hence the polarization potenial change with time varies correspondingly.With the existance of solution resis- tance,the transport of charge can not complete instantaneously and the polarization potential can not change abruptly. On neglecting the influence of solution resistance,based on the law of Killkoff,the polarization potential must abruptly change at the moment of coulostatic perturbation.At the same time the circuit must be controlled by coulostat. Regardlessly at the moment of abrupt change or during all process of transport charge the constant theorem of charge must be obeyed. Thus we can set up the start condition of the transition process and derive the equations of polarization potential decay curve under cou- lostatic perturbation.