弹道聚并引发相变中的反常温度依赖
Anomalous temperature dependence in phase transitions via ballistic coalescence
- Jawaharlal Nehru Centre for Advanced Scientific Research（贾瓦哈拉尔·尼赫鲁高级科学研究中心）
- Birla Institute of Technology and Science, Pilani, Hyderabad Campus（比拉理工与科学学院，皮拉尼海得拉巴校区）
- Indian Institute of Technology Bhubaneswar（布巴内斯瓦尔印度理工学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
通过Lennard-Jones模型研究发现，弹道聚并理论可捕捉相变中平均团簇质量增长指数的反常非单调温度依赖，其适用范围广，爆炸式增长特性对气溶胶等聚并过程研究具重要意义。
AI中文摘要：
我们研究单组分Lennard-Jones模型内的相变动力学。当粒子密度足够低时，会形成离散团簇，这些团簇可在无粘蒸汽背景中做弹道运动。团簇发生粘性碰撞，进而形成更大的聚集体，在超低温下可具有分形性质。随温度变化，平均团簇质量代数增长的指数会发生改变，呈现明显的非单调特征。我们在二维和三维空间维度下，通过弹道聚并理论（ballistic aggregation theory）捕捉到这种反常行为，表明该理论的适用范围远大于通常考虑的团簇运动无关联的情况。对该理论的分析显示，弹道聚并甚至可以呈指数级快速发生，这与被动物质相变的传统代数图像形成鲜明对比。我们讨论了这种爆炸式增长可实现的场景，此外，研究结果对理解气溶胶、宇宙尘埃及其他聚并过程的结构与生长具有广泛相关性。
英文摘要：
We study kinetics of phase transitions within a single component Lennard-Jones model. For low enough particle densities disconnected clusters form that can move ballistically in an inviscid vapor background. The clusters undergo sticky collisions, thereby forming larger aggregates, which can be of fractal nature at ultra cold temperatures. As the temperature is varied, the exponent of the algebraic growth of average cluster mass changes, exhibiting pronounced nonmonotonic character. We capture this anomalous behavior, in two and three space dimensions, within a ballistic aggregation theory. We show that the scope of the theory is much broader than the typically considered case where cluster motions are uncorrelated. An analysis of the theory shows that ballistic aggregation can even occur exponentially fast. This is in sharp contrast with the conventional algebraic picture, regarding passive matter phase transitions. We discuss scenario where such explosive growth can be realized. In addition, our results are widely relevant in understanding structure and growth in aerosols, cosmic dust and other aggregation processes.
