在非极性颗粒型布朗振动器中出现异常聚合
Yangrui Chen1, Jie Zhang2,3
1School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China.
Nature communications
|July 17, 2024
概括
颗粒状材料表现出四个阶段的集群行为,由粒子相互作用和体积分数驱动. 在硬盘系统中观察到的这种集体运动与活性粒子动力学理论一致.
科学领域:
- 物理 物理学 物理
- 材料科学 材料科学 材料科学
- 统计力学 统计力学
背景情况:
- 颗粒状材料表现出复杂的行为,不能完全由平衡统计力学解释.
- 了解准二维 (quasi-2D) 颗粒系统的集体动态对于各种应用至关重要.
研究的目的:
- 在布朗运动下研究准二维颗粒物质的结构和动态.
- 在这些系统中识别和描述不同的阶段和新出现的行为,如群体化.
主要方法:
- 利用布朗的振动器来模拟二维粒状磁盘系统中的粒子运动.
- 系统地从0.111到0.832变化的包装分数 (φ) 来观察相位过渡.
- 分析了系统行为,以识别不同的阶段:颗粒液体,聚合液体,多晶体和晶体.
主要成果:
- 在硬颗粒式磁盘系统中观察到大规模的聚合行为,异常聚合在φ = 0.317时出现,在φ = 0.713时停止.
- 确定了四个不同的阶段:颗粒液体,聚合液体,多晶体和晶体,其中的过渡与密度波动有关.
- 发现颗粒状和集体流体相显著偏离平衡硬盘模型和以前的实验.
结论:
- 这些颗粒系统中的集体运动源于活性力和不弹性碰撞诱导的相互作用之间的平衡,由体积分数调制.
- 在硬颗粒状磁盘中观察到的集群行为与缺乏明确对齐机制的活性粒子理论模型保持一致.
- 这些发现表明,在非平衡的颗粒物质中,集体运动的新机制.
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