发表机构
Graduate School of Advanced Science and Engineering, Hiroshima University; Graduate School of Integrated Arts and Sciences, Hiroshima University（广岛大学先进理工学研究科; 广岛大学综合理工学研究科）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究结合超声与非弹性X射线散射技术，观测到水-醇混合物的动态涨落强度随醇组成、温度降低而增大，证实涨落源于水的过冷区，混合醇会消除涨落，为水的热力学异常讨论提供了新视角。
AI 中文摘要
我们将近年开发的一种动态涨落测量方法应用于宽组成范围和宽温度范围的液态水-甲醇混合物，该方法结合超声与非弹性X射线散射技术，利用声波探测液体中介观尺度的涨落——即异质性程度。结果显示，动态涨落强度随醇组成降低、温度降低而增大，该趋势也在水-乙醇、水-甘油混合物中被观测到。由此我们得出结论：这些涨落的起源仅在于水的低温（过冷）区，与醇混合会消除动态涨落；这一“混合物质可降低涨落或异质性”的结论初看反常，实则与解释水热力学异常的液-液相变假说框架一致，也与我们近年对水在宽温度、压力范围下动态涨落强度的测量结果相符。长期以来已知水-醇混合物在低组成下存在多种热力学异常，过往对此有诸多讨论，本研究的发现为这些讨论提供了新视角。
英文摘要
We applied a dynamic fluctuation measurement method to liquid water-methanol mixtures over a wide range of compositions and temperatures. This method, which we developed in recent years, combines ultrasonic and inelastic X-ray scattering techniques to detect mesoscopic-level fluctuations-that is, the degree of heterogeneity-in liquids using sound waves. The results showed that the strength of dynamic fluctuations increased as the alcohol composition decreased and as the temperature decreased. This trend was also observed in water-ethanol and water-glycerol mixtures. From these results, we concluded that the origin of these fluctuations lies in the low-temperature (supercooled) region of water alone, and that mixing with alcohol eliminates the dynamic fluctuations. This conclusion-that mixing substances reduces fluctuations or heterogeneity-may seem strange at first glance, but it is actually consistent with the framework of the liquid-liquid phase transition hypothesis, which explains the thermodynamic anomalies of water. It also aligns with the results of our recent measurements of the strength of dynamic fluctuations in water across a wide range of temperature and pressure conditions. It has long been known that various thermodynamic anomalies exist in water-alcohol mixtures at low compositions, and while there have been various discussions on this topic in the past, our current findings offer a new perspective on these discussions.
Comments31pages, 8figures
