The experiments , comparison and analysis for the three thickness measurement methods :two-beam diffraction method , contaminationspot method and contamination line method were carried out.
前言： 对用电子显微镜测量薄膜厚度的三种方法：双束衍射法、污斑法、污线法进行了实验及比较分析。
2
Over several decades China's industrial boom has caused widespread contamination by heavy metals such as lead and cadmium, resulting in a silent health epidemic that can be difficult to spot.