Universality aids consistent understanding of physical properties and states of matter where a theory predicts how a property of a phase (solid, liquid, and gas) changes with temperature or pressure. Here, we show that the matter above the critical point has a remarkable double universality. The first universality is the transition between the liquid-like and gas-like states seen in the crossover of the specific heat on the dynamical length with a fixed inversion point. The second universality is the operation of this effect in many supercritical fluids, including N 2 , CO 2 , Pb, H 2 O, and Ar. Despite different structure and chemical bonding, the transition has the same fixed inversion point deep in the supercritical state. This advances our understanding of the supercritical state previously considered to be a featureless area on the phase diagram and a theoretical guide for improved deployment of supercritical fluids in green and environmental applications.

中文翻译：

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超临界状态跃迁的双重普遍性

普遍性有助于对物理特性和物质状态的一致理解，其中理论预测相（固体、液体和气体）的特性如何随温度或压力变化。在这里，我们证明了临界点以上的物质具有显着的双重普遍性。第一个普遍性是在具有固定反转点的动态长度上的比热的交叉中看到的液体状和气体状状态之间的过渡。第二个普遍性是这种效应在许多超临界流体中的作用，包括 N2, 一氧化碳2, 铅, 氢2O, 和 Ar。尽管结构和化学键不同，但在超临界状态深处，过渡具有相同的固定反转点。这促进了我们对以前被认为是相图上无特征区域的超临界状态的理解，并为改进超临界流体在绿色和环境应用中的部署提供了理论指导。