一种体积物态方程物理基础的讨论

 对体积物态方程v-v_c=(R/p)(h-h_c)的物理基础进行了讨论。给出了该方程的一个统计力学形式证明,从而给出了方程中物质参数的微观定义,亦即给出了该方程的具体表达式。在R=R(p)假设下,给出了方程中物质参数的热力学表达式,通过分析其与Debye理论下的对应态定律的一致性,证明了该假设的近似合理性,从而也就证明了该方程的成立并不受其建立时所依据的定压比热为常数这一过强条件的限制。进一步地,通过与物质参数热力学表达式常压实验值的比较,指出了单纯的R=R(p)假定存在一定的局限,该局限引起的偏差随温度的升高而增大,在常压下的高温区间,该偏差在20%左右。

THE PHYSICS BASE OF THE NEW EQUATION OF STATE

The new equation of state (N-EOS),v-vc=(R/p)(h-hc) with the assumption R=R(p) (where v,p,h are specific volume,pressure and specific enthalpy respectively,R is substance parameter,the subscript c refers to the state not depending temperature),had been good used in the study of the shock compression of porous,since it be developed in 1995 by Qiang Wu et al.But,this EOS was developed through thermodynamic and under a not very rational condition that the specific heat at constant pressure cp remains constant.So its physics base has not been proofed and its concrete form has not been got.In this work,a form proof has been made to the N-EOS by solid physics and statistical mechanics,and therefor the normal micro formula of substance parameter has been got.Through this,we proofed that the physical base of the N-EOS with R=R(p) is the law of corresponding states of the Debye theory,and thus its validity not limited by the assumption of cp remains constant.Additional,the calculation to the thermodynamic R under normal pressure by experimental data shows that R=R(p) is not a very accurate approximation.A tentative discussion has been made to this and the corresponding problem of the γ=γ(v) approximation of the Grüneisen EOS.