基于Hermite插值的改进激光诱导击穿光谱基线校正方法及其对铀矿定量模型性能提升  

Improved baseline correction method for laser-induced breakdown spectroscopy based on Hermite interpolation and its performance improvement on quantitative models of uranium ore

作　　者：许应铜 舒开强 朱梦娇 宋骁冉 林庆宇 段忆翔 XU Yingtong;SHU Kaiqiang;ZHU Mengjiao;SONG Xiaoran;LIN Qingyu;DUAN Yixiang(School of Mechanical Engineering,Sichuan University,Chengdu 610065,China;College of Mechanical and Control Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]四川大学机械工程学院,四川成都610065 [2]桂林理工大学机械与控制工程学院,广西桂林541004

出　　处：《冶金分析》2024年第5期1-7,共7页Metallurgical Analysis

基　　金：四川省科技厅重点研发项目(2022YFG0235)。

摘　　要：铀元素被广泛应用于能源、医疗、工业和国防等领域,具有极为重要的战略价值。激光诱导击穿光谱(LIBS)是一种通用的元素分析技术,在诸多领域均有广泛应用。基于LIBS对组成复杂的铀矿检测分析时,容易受到连续背景辐射、散射光等的影响,造成基线升高,使得定量效果不准确。为了提高LIBS对铀矿分析效果,本文提出了一种改进的基线校正算法用于校正铀矿光谱的基线,进而提高对铀矿多元素的定量准确度。该算法基于分段三次Hermite插值方法改进,将改进后的方法与修正最小二乘法(Modpoly)、改进的修正最小二乘法(Imodpoly)和自适应迭代重加权惩罚最小二乘法(airPLS)对模拟光谱进行处理。对比结果显示,改进的方法在处理模拟光谱时,信背比达到了13.025,高于其他3种方法。基于改进方法进行光谱基线校正后,铀矿多元素LIBS定量的单变量模型决定系数(R^(2))有明显提升,且多变量模型中预测总误差仅为0.0737%,多变量模型R2从0.95527提升到0.97936。所提出的改进基线校正方法能够较好提高LIBS对铀矿中铀元素定量分析的准确度。Uranium is widely used in many fields such as energy,medical,industrial and national defense,and it possesses very important strategic value.Laser-induced breakdown spectroscopy(LIBS)is a general technology for elemental analysis,which has been widely applied in various fields.During the analysis and detection of uranium ore with complex composition by LIBS,it is easily affected by the continuous background radiation and scattered light,leading to the increase of baseline as well as inaccurate quantitative results.In order to improve the analysis results of uranium ore by LIBS,an improved baseline correction method was proposed in this paper to correct the baseline of uranium ore spectrum,thus enhancing the quantitative accuracy of multi-elements in uranium ore.This algorithm was improved based on piecewise cubic Hermite interpolation.The improved method,the modified least squares method(Modpoly),improved modified least squares method(Imodpoly)and adaptive iterative reweighting punishment least square method(airPLS)was applied for the treatment of simulated spectra,respectively.The comparison results showed that the improved method achieved a signal-to-noise ratio of 13.025 in processing simulated spectra,which was higher than the other three methods.When the spectral baseline was corrected based on the improved method,the determination coefficient(R2)of univariate model for LIBS quantification of multi-elements in uranium ore was improved significantly.Moreover,the total error of prediction in multivariable model was only 0.737%,and the R^(2) of multivariable model increased from 0.95527 to 0.97936.The improved baseline correction method proposed in this study could well enhance the accuracy of quantitative analysis of uranium ore by LIBS.

关 键 词：激光诱导击穿光谱(LIBS) 基线校正 HERMITE插值 铀矿 铀 

分 类 号：O657.319[理学—分析化学] TL27[理学—化学]