标题： 观察密集颗粒物质在微重力下的玻璃化转变和 jamming 转变 显示英文标题

标题： Observing the Glass and Jamming Transitions of Dense Granular Material in Microgravity

摘要： 本研究调查了在国际空间站（ISS）上长时间微重力条件下的一种弱脉冲聚合物球（聚苯乙烯小球）颗粒系统。这些小球通过扩散波谱学（DWS）进行测量，并用均方位移（MSD）来描述。我们的目标是利用该技术展示微重力下密集颗粒介质中玻璃态动力学的首次实验证据，并随后将这些结果与地面测量结果进行比较，以观察在没有重力影响的情况下这些动力学性质如何发生变化。我们的结果显示，在微重力条件下，当样本致密化时，玻璃态动力学出现在比地面低1.6%的体积分数下。我们还通过比较我们在ISS上的样品最终阻塞点和地面设置下的最终阻塞点，展示了重力如何影响可以制备的颗粒系统的密度。结果显示，在空间中的阻塞发生在比地面低0.5%的体积分数下。这表明，当颗粒系统处于更强的引力场中时，我们可以创建更致密的状态。 显示英文摘要

摘要： The present study investigates a weakly pulsed granular system of polystyrene spheres under long-time microgravity conditions on the International Space Station (ISS). The spheres are measured using Diffusing Wave Spectroscopy (DWS) and are described by mean square displacements (MSDs). Our aim is to use this technique to show the first experimental evidence of glassy dynamics in dense granular media in microgravity and subsequently compare these results with ground-based measurements to see how the nature of these dynamics change without the influence of gravity. Our results show that as we densify the sample in microgravity, glassy dynamics appear at a volume fraction 1.6\% lower than on ground. We also show how the influence of gravity can affect how dense a granular system one can prepare by comparing the final jamming point of our sample on the ISS compared to our ground setup. We show that jamming occurs at a volume fraction 0.5\% lower in space compared to on ground. Showing that we can create denser states when a granular system is in the presence of a stronger gravitational field.