We investigate numerically and analytically size-polydisperse granular mixtures immersed into a molecular gas. We show that the equipartition of granular temperatures of particles of different sizes is established; however, the granular temperatures significantly differ from the temperature of the molecular gas. This result is surprising since, generally, the energy equipartition is strongly violated in driven granular mixtures. Qualitatively, the obtained results do not depend on the collision model, being valid for a constant restitution coefficient $\varepsilon$, as well as for the $\varepsilon$ for viscoelastic particles. Our findings may be important for astrophysical applications, such as protoplanetary disks, interstellar dust clouds, and comets.

中文翻译：

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分子气体中的多分散粉尘：能量均分与非均分

我们在数值和分析上研究了浸入分子气体中的大小分散的颗粒状混合物。我们表明建立了不同大小的颗粒的颗粒温度的均分；然而，颗粒温度与分子气体的温度明显不同。该结果是令人惊讶的，因为通常在驱动的颗粒混合物中强烈违反了能量分配。定性地，获得的结果不依赖于碰撞模型，对于恒定的恢复系数有效$\varepsilon$，以及 $\varepsilon$用于粘弹性颗粒。我们的发现对于天体物理应用（例如原行星盘，星际尘埃云和彗星）可能很重要。