标题： 由几何驱动的喷射现象导致了雨水滴对植物和真菌的传播 显示英文标题

标题： Geometry-driven jets underlie dispersal of plants and fungi by raindrops

摘要： 液滴在凹面表面的影响尚不明确，尽管它与一种在几种植物和真菌中独立进化的传播方式有关。 这种传播方式依赖于弹射杯，一种特殊的器官，利用雨滴将繁殖单元从母体生物上分散出去。 我们研究了液滴对模仿弹射杯的锥形腔体的影响，并发现这种影响可能导致两种类型的喷射流形成，这对自然中的传播似乎至关重要。 我们建立了一个最小运动学模型，解释了喷射流的形成，涉及流体粒子沿圆锥表面测地线（最短路径）的运动，并预测了优化喷射流形成的圆锥角度，这与天然弹射杯的几何结构一致。 显示英文摘要

摘要： The impact of droplets on concave surfaces is poorly understood, although it is relevant to a mode of dispersal that has evolved independently in several species of plants and fungi. This mode relies on splash-cups, specialized organs that use raindrops to disperse reproductive units away from the parent organism. We investigated the impact of droplets on conical cavities that mimic splash-cups and we found that such impact may lead to the formation of two types of jets, which appear essential for dispersal in nature. We built a minimal kinematic model that explains jet formation, involving the motion of fluid particles along geodesics (shortest paths) on the cone surface and we predicted cone angles that optimize jet formation, consistent with the geometries of natural splash-cups