AI 中文总结
研究通过X射线断层扫描对比不同重力及摩擦力下颗粒堆积，发现降低重力与增强摩擦力效果类似，二者能使颗粒堆积呈现相同特性，源于机械稳定性约束松弛，重力还保留独特接触尺度特征，为颗粒堆积提供统一统计描述。
AI 中文摘要
我们使用X射线断层扫描，比较了在有效重力降低的浮力条件下制备的颗粒堆积与具有系统变化摩擦力的正常重力颗粒堆积。结果表明，降低重力以类似于增加摩擦力的方式降低了随机松散堆积极限。重力降低和摩擦力增强的颗粒堆积表现出相同的体积分布、压实度和熵，表明这两种途径对机械稳定状态进行统计等效的爱德华兹体积系综采样。这种等效性源于机械稳定性约束的共同松弛。然而，降低重力通过更各向同性的接触方向保留了独特的接触尺度特征。这些发现确定重力是控制爱德华兹框架内机械稳定状态统计可达性的物理因素，并提供了对通过不同物理途径形成的颗粒堆积的统一统计描述。
英文摘要
Using X-ray tomography, we compare granular packings prepared under buoyancy-reduced effective gravity with normal gravity packings of particles with systematically varied friction. We show that reducing gravity lowers the random loose packing limit in a manner analogous to increasing friction. Granular packings under reduced gravity and with enhanced friction exhibit identical volume distributions, compactivity, and entropy, indicating that both routes sample statistically equivalent Edwards volume ensembles of mechanically stable states. This equivalence originates from a common relaxation of the mechanical stability constraint: under both conditions, fewer particles are required to participate in the underlying load-bearing bridge structures, leading to a lower contact-number requirement and a higher density of mechanically stable states. Nevertheless, reduced gravity retains a distinct contact-scale signature through more isotropic contact orientations. These findings identify gravity as a physical control governing the statistical accessibility of mechanically stable states within the Edwards framework and provide a unified statistical description of granular packings formed through different physical routes.
Comments20 pages, 6 figures
