Abstract: The hard-sphere three-parameter equation of state(CSPT)proposed in the previous paper(Li et al.1991)was modified by a new temperature relation for the pseudo-critical compressibility ξand the temperaturecorrection factor α(T_r)of the attractive parameter.Vapor pressures and Saturated liquid densities of 105 purecompounds were calculated by the modified version.Results show that correlations of saturated properties at lowreduced temperatures and thermodynamic properties in the vicinity of critical region were significantly improved.Furthermore,characteristic parameters of this modified version were generalized by acentric factor ωand criticalcompressibility Z_c to predict saturated liquid densities of 72 polar substances and the latent heat of vaporizationfor 151 substances including strongly polar compounds with satisfactory results.

摘要： The hard-sphere three-parameter equation of state(CSPT)proposed in the previous paper(Li et al.1991)was modified by a new temperature relation for the pseudo-critical compressibility ξand the temperaturecorrection factor α(T_r)of the attractive parameter.Vapor pressures and Saturated liquid densities of 105 purecompounds were calculated by the modified version.Results show that correlations of saturated properties at lowreduced temperatures and thermodynamic properties in the vicinity of critical region were significantly improved.Furthermore,characteristic parameters of this modified version were generalized by acentric factor ωand criticalcompressibility Z_c to predict saturated liquid densities of 72 polar substances and the latent heat of vaporizationfor 151 substances including strongly polar compounds with satisfactory results.