When a container filled with granular material is subjected to sinusoidal vibration in microgravity, dependent on the amplitude of the oscillation, the granulate may exhibit one of two distinct dynamical modes: at low amplitude, a gas-like state is observed, where the particles are relatively homogeneously distributed within the container, almost independent of the phase of the oscillation. In contrast, for large amplitude, collective motion of the particles is favoured, termed collect-and-collide regime. Both regimes are characterized by very different dissipation characteristics. A recent model predicts that the regimes are separated by a sharp transition due to a critical amplitude of the vibration. Here we confirm this prediction of a sharp transition and also the numerical value of the critical amplitude by means of experiments performed under conditions of weightlessness.

中文翻译：

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微重力下的颗粒阻尼器：运行模式之间的急剧过渡

当装有颗粒材料的容器在微重力下经受正弦振动时，取决于振荡的幅度，颗粒可能会表现出两种不同的动力学模式之一：在低幅度下，会观察到类似气体的状态，其中颗粒是相对均匀地分布在容器内，几乎与振荡的相位无关。相反，对于大振幅，有利于粒子的集体运动，称为收集和碰撞方式。两种方案的特征在于非常不同的耗散特性。最近的模型预测，由于振动的临界振幅，各状态之间由一个急剧的过渡分开。