Thirdly, the reading material points out that fuel cells are an economic alternative because using hydrogen is more efficient than burning oil.

第三，阅读材料指出燃料电池是一种经济的替代方案， 因为使用氢比燃烧石油更有效。

Since this work uses the material point method, which is a hybrid simulation technique that uses both particles and grids, the delta x row denotes the resolution of the simulation grid.

这项工作使用了“物质点法”，即一种同时使用粒子和网格的混合仿真技术，Δx行表示模拟网格的分辨率。