In theoretical study of acidization of sandstone rocks, Lund and Fogley developed two models, which are marked by the quasilinear system of partial differential equations.

• 在酸化砂岩油层的理论研究中,出现了直线流模型与径向流模型,这两个模型皆是用一阶拟线性偏微分方程组的定解问题来刻划的。