标题： 真实沙丘中颗粒上的合力：如何测量它？ 显示英文标题

标题： Resultant force on grains of a real sand dune: How to measure it?

摘要： 沙丘是在地球、火星和其他天体的沙质地形上由流体流动形成的床形结构。 尽管它们很常见，但由于涉及的颗粒数量庞大，理解沙丘在颗粒尺度上的动态过程仍然具有挑战性。 在本研究中，我们展示了一种新方法，利用图像来估算作用在单个沙丘颗粒上的力。 通过结合水下实验、高速摄像记录、离散数值模拟以及一个专门训练的卷积神经网络，我们可以高精度地量化这些力。 这种方法在研究颗粒动力学方面取得了突破，提供了一种新的测量方式，不仅适用于沙丘颗粒，还适用于较小的物体，如岩石、巨石、探测器和人造结构，在地球和火星的卫星图像中都能观察到。 这项技术扩展了我们分析和理解不同环境中流体-颗粒相互作用的能力。 显示英文摘要

摘要： Dunes are bedforms found on sandy terrains shaped by fluid flow on Earth, Mars, and other celestial bodies. Despite their prevalence, understanding dune dynamics at the grain scale is challenging due to the vast number of grains involved. In this study, we demonstrate a novel approach to estimate the forces acting on individual dune grains using images. By combining subaqueous experiments, high-speed camera recordings, discrete numerical simulations, and a specially trained convolutional neural network, we can quantify these forces with high accuracy. This method represents a breakthrough in studying granular dynamics, offering a new way to measure forces not only on dune grains but also on smaller objects, such as rocks, boulders, rovers, and man-made structures, observed in satellite images of both Earth and Mars. This technique expands our ability to analyze and understand fluid-grain interactions in diverse environments.