A modified Martin–Hou (M–H) equation of state (EOS) for the accurate representation of thermodynamic property data of some pure substances in liquid phase is presented in this work. The improvement is achieved by substituting a new parameter η into the original M–H EOS. Eighteen pure substances are chosen to construct the dependency relationship of η on reduced temperature T_r and acentric factor ω. Furthermore, to verify the effectiveness and improvement of the modified M–H EOS, the calculated values of the saturated vapor and liquid molar volumes are compared with the literature data in the reduced temperature ranging from approximately 0.6 to 1.0. The results show that the modified M–H EOS perform a good prediction in gaseous phase for pure substances with the average absolute deviation (AAD) generally less than 1%, and more precise liquid molar volume values can be obtained with the modified equation. In liquid phase, the AAD of the modified M–H EOS is 3.71%, which is much lower than 6.16% of the original M–H EOS.

中文翻译：

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Martin-Hou 状态方程的改进，用于更精确地预测液体区域

本文提出了一种改进的 Martin-Hou (M-H) 状态方程 (EOS)，用于准确表示液相中某些纯物质的热力学性质数据。通过将新参数η代入原始 M-H EOS 来实现改进。选取 18 种纯物质构建η对降低温度T _r和无心因子ω的依赖关系. 此外，为了验证改进的 M-H EOS 的有效性和改进，将饱和蒸气和液体摩尔体积的计算值与降低温度范围内约 0.6 至 1.0 的文献数据进行比较。结果表明，修正后的M-H EOS对纯物质在气相中的预测效果很好，平均绝对偏差（AAD）一般小于1%，修正后的方程可以得到更精确的液体摩尔体积值。在液相中，改性 M-H EOS 的 AAD 为 3.71%，远低于原始 M-H EOS 的 6.16%。