Laser induced breakdown Spectroscopy(LIBS)was applied for the elemental analysis and exposure of the heavy metals in betel leaves in air.Pulsed Nd∶YAG(1064 nm)in conjunction with a suitable detector(LIBS 2000+,Ocean ...Laser induced breakdown Spectroscopy(LIBS)was applied for the elemental analysis and exposure of the heavy metals in betel leaves in air.Pulsed Nd∶YAG(1064 nm)in conjunction with a suitable detector(LIBS 2000+,Ocean Optics,Inc)having the optical resolution of 0.06 nm was used to record the emission spectra from 220 to 720 nm.Elements like Al,Ba,Ca,Cr,Cu,P,Fe,K,Mg,Mn,Na,P,S,Sr,and Zn were found to present in the samples.The relative abundances of the observed elements were calculated through standard calibration curve method,integrated intensity ratio method,and weight percentage LIBS approach.LIBS findings were validated by comparing its results with the results obtained using a typical analytical technique of Inductively Coupled plasma-optical emission spectroscopy(ICP-OES).Limit of detection(LOD)of the LIBS system was also estimated for heavy metals.The experience gain through this work implies that LIBS could be highly applicable for testing the quality and purity of food products.展开更多
飞灰含碳量是评价锅炉燃烧效率的重要指标之一，对其进行在线测量有助于实时进行燃烧优化调整，从而提高整个机组的经济性和安全性。利用螺杆式给粉机搭建飞灰颗粒流含碳量测量台架，将脉冲激光直接作用于飞灰颗粒流，形成等离子体，利...飞灰含碳量是评价锅炉燃烧效率的重要指标之一，对其进行在线测量有助于实时进行燃烧优化调整，从而提高整个机组的经济性和安全性。利用螺杆式给粉机搭建飞灰颗粒流含碳量测量台架，将脉冲激光直接作用于飞灰颗粒流，形成等离子体，利用激光诱导击穿光谱技术测量飞灰颗粒流中的含碳量信息。重点研究了激光能量对飞灰颗粒流中未燃碳有效激发和测量的影响规律。研究结果显示，在40～130 m J能量的脉冲激光作用下，碳谱线强度随着激光能量的增大线性增强，而其信噪比则先增加后趋于稳定，无效光谱的剔除率则呈下降趋势。本实验条件下，激光能量在90～100 m J之间，可得到较强的等离子体发射信号和较优的光谱数据利用率。因而激光能量与颗粒流的激发状态、碳元素特征谱线强度等密切相关。合理的激光能量有利于保证飞灰颗粒流的有效稳定激发，并获得具有良好信噪比的等离子体光谱信号。展开更多
文摘Laser induced breakdown Spectroscopy(LIBS)was applied for the elemental analysis and exposure of the heavy metals in betel leaves in air.Pulsed Nd∶YAG(1064 nm)in conjunction with a suitable detector(LIBS 2000+,Ocean Optics,Inc)having the optical resolution of 0.06 nm was used to record the emission spectra from 220 to 720 nm.Elements like Al,Ba,Ca,Cr,Cu,P,Fe,K,Mg,Mn,Na,P,S,Sr,and Zn were found to present in the samples.The relative abundances of the observed elements were calculated through standard calibration curve method,integrated intensity ratio method,and weight percentage LIBS approach.LIBS findings were validated by comparing its results with the results obtained using a typical analytical technique of Inductively Coupled plasma-optical emission spectroscopy(ICP-OES).Limit of detection(LOD)of the LIBS system was also estimated for heavy metals.The experience gain through this work implies that LIBS could be highly applicable for testing the quality and purity of food products.
文摘飞灰含碳量是评价锅炉燃烧效率的重要指标之一，对其进行在线测量有助于实时进行燃烧优化调整，从而提高整个机组的经济性和安全性。利用螺杆式给粉机搭建飞灰颗粒流含碳量测量台架，将脉冲激光直接作用于飞灰颗粒流，形成等离子体，利用激光诱导击穿光谱技术测量飞灰颗粒流中的含碳量信息。重点研究了激光能量对飞灰颗粒流中未燃碳有效激发和测量的影响规律。研究结果显示，在40～130 m J能量的脉冲激光作用下，碳谱线强度随着激光能量的增大线性增强，而其信噪比则先增加后趋于稳定，无效光谱的剔除率则呈下降趋势。本实验条件下，激光能量在90～100 m J之间，可得到较强的等离子体发射信号和较优的光谱数据利用率。因而激光能量与颗粒流的激发状态、碳元素特征谱线强度等密切相关。合理的激光能量有利于保证飞灰颗粒流的有效稳定激发，并获得具有良好信噪比的等离子体光谱信号。
