查询词典 PEC

Time-Frequency analysis method is applied to the analysis of PEC signals with the aim of discriminating the occurrence of corrosion from the simultaneous variations of lift-off, smoothed pseudo Wigner-Ville distribution is used to get the signal spectrum map. The method of extracting the lowest energy area as the classification eigenvalue is proposed, and a good classification result is acquired.

采用时频分析的方法对同时出现腐蚀缺陷和提离变化的情况进行了识别，利用平滑的伪Wigner-Ville分布得到了信号的谱图，提出了提取谱图中最低能量区域面积作为特征量进行识别的方法，取得了较好的识别效果。

The contents of TOC, DOC, POC and PEC are generally higher in the samples of wet-season than that in the dry season.

干季降雨的平均TOC含量为5.65 mg/l，平均DOC含量为3.26 mg/l，平均POC含量为2.48 mg/l，平均。

In the chapter 2, the theoretic knowledge about the photosensitive resin and the grinding tools was firstly introduced.

第二章阐述了光固化树脂结合剂磨具的相关理论研究。

Do not use the program's indenting or margin-setting features; these will be added during typesetting.

不要使用缩排，页面边缘设置之类的选项，偶看不大懂。