论文标题
在混合物中的相关功能与有力的最接近的邻居不同类型的相关性：一种大小相对的情况
Correlation functions in mixtures with energetically favoured nearest-neighbours of different kind: a size-asymmetric case
论文作者
论文摘要
通过理论和蒙特卡洛模拟研究了具有不同直径和不同颗粒之间的方形吸引力的硬球的二进制混合物。在我们的介观理论中，考虑了两个组成部分的体积分数的局部波动。除了很小的距离外，还获得了模拟和理论结果之间的半定量一致性。相关函数表现出指数抑制的振荡，并由相互作用势确定的周期，并且随着直径比的增加而振幅和相关长度显着增加。不对称的尺寸不对称也会减少较大颗粒的较小颗粒数量的波动。对于小尺寸的不对称性，对于两个组分的可比体积分数而发生的最强相关性。当尺寸比增加时，结构因子的最大值移至较大的粒子的较大体积分数，并且尺寸比最大为4，最大值超出了容量分数的可访问范围。我们的结果表明，当不同颗粒的邻域在能量上有利时，即使在相对较高的温度下，颗粒也比随机分布中的分布得多，尤其是对于大尺寸不对称性。
Binary mixtures of hard-spheres with different diameters and square-well attraction between different particles are studied by theory and Monte Carlo simulations. In our mesoscopic theory, local fluctuations of the volume fraction of the two components are taken into account. Semi-quantitative agreement between the simulation and theoretical results is obtained, except from very small distances. The correlation functions exhibit exponentially damped oscillations, with the period determined by the interaction potential, and both the amplitude and the correlation length increasing significantly with increasing diameter ratio. Increasing size asymmetry leads also to decreasing fluctuations of the number of the smaller particles in the attractive shell of the bigger ones. For small size asymmetry, the strongest correlations occur for comparable volume fraction of the two components. When the size ratio increases, the maximum of the structure factor moves to a larger volume fraction of the bigger particles, and for the size ratio as large as 4, the maximum goes beyond the accessible range of volume fractions. Our results show that when the neighbourhood of different particles is energetically favoured, the particles are much more uniformly distributed than in the random distribution even at relatively high temperature, especially for large size asymmetry.
