A simple schlieren technique is used to visualize strong gradients of refractive index in liquids under atmospheric conditions and elevated pressure. The gradients are mainly caused by concentration differences within a thin liquid sheet. A simple system using Matlab and open source applications is designed and applied to demonstrate the challenges and limitations of a quantitative approach for strong gradients in liquids. Possibilities for the optimization regarding the detection of strong gradients are shown, but rather qualitative than quantitative results are obtained.

中文翻译：

---

背景定向Schlieren方法在强折射梯度液体体系中的应用

一种简单的schlieren技术用于在大气条件和高压下可视化液体中折射率的强梯度。梯度主要由薄液体片内的浓度差异引起。设计并使用了一个使用Matlab和开放源代码应用程序的简单系统，以演示液体中强梯度定量方法的挑战和局限性。示出了关于检测强梯度的优化的可能性，但是获得了定性而不是定量的结果。