[1] Tanaka H, Fujii A, Fujimoto S et al. Microwave-assisted two-step process for the synthesis of a single-phase Na-A zeolite from coal fly ash[J]. Advanced Powder Technology, 19, 83-94(2008).

[2] Cheng Q M, Hu X Q, Wang Y F et al. Summary of measurement methods of carbon content in fly ash[J]. Journal of Shanghai University of Electric Power, 27, 519-524(2011).

[3] Syta O, Wagner B, Bulska E et al. Elemental imaging of heterogeneous inorganic archaeological samples by means of simultaneous laser induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry measurements[J]. Talanta, 179, 784-791(2018).

[4] Bonta M, Gonzalez J J, Quarles C D. Jr, et al. Elemental mapping of biological samples by the combined use of LIBS and LA-ICP-MS[J]. Journal of Analytical Atomic Spectrometry, 31, 252-258(2016).

[5] Taparli U A, Jacobsen L, Griesche A et al. In situ laser-induced breakdown spectroscopy measurements of chemical compositions in stainless steels during tungsten inert gas welding[J]. Spectrochimica Acta Part B: Atomic Spectroscopy, 139, 50-56(2018).

[6] Guo L B, Zhang D, Sun L X et al. Development in the application of laser-induced breakdown spectroscopy in recent years: a review[J]. Frontiers of Physics, 16, 1-25(2021).

[7] Shang D, Sun L X, Qi L F et al. Quantitative analysis of LIBS iron ore slurry based on cyclic variable filtering and nonlinear partial least squares[J]. Chinese Journal of Lasers, 48, 2111001(2021).

[8] Kurihara M, Ikeda K, Izawa Y et al. Optimal boiler control through real-time monitoring of unburned carbon in fly ash by laser-induced breakdown spectroscopy[J]. Applied Optics, 42, 6159-6165(2003).

[9] Ctvrtnickova T, Mateo M P, Yañez A et al. Characterization of coal fly ash components by laser-induced breakdown spectroscopy[J]. Spectrochimica Acta Part B: Atomic Spectroscopy, 64, 1093-1097(2009).

[10] Yao S C, Lu J D, Zheng J P et al. Analyzing unburned carbon in fly ash using laser-induced breakdown spectroscopy with multivariate calibration method[J]. Journal of Analytical Atomic Spectrometry, 27, 473-478(2012).

[11] Bian J T, Yin K J, Yao S C et al. Quantitative analysis of unburned carbon in fly ash by laser induced breakdown spectroscopy in different atmosphere[J]. Laser & Optoelectronics Progress, 53, 043002(2016).

[12] Bai K J, Yao S C, Lu J D et al. Correction of C-Fe line interference for the measurement of unburned carbon in fly ash by LIBS[J]. Journal of Analytical Atomic Spectrometry, 31, 2418-2426(2016).

[13] Hu R M, Wang Z Z, Liu R W et al. Quantitative analysis of unburned carbon in fly ash by laser-induced breakdown spectroscopy[J]. Acta Photonica Sinica, 47, 0847005(2018).

[14] Ma W Z, Dong M R, Huang Y R et al. Quantitative analysis method of unburned carbon content of fly ash by laser-induced breakdown spectroscopy[J]. Infrared and Laser Engineering, 50, 20200441(2021).

[15] Li X H, Yang S B, Fan R W et al. Discrimination of soft tissues using laser-induced breakdown spectroscopy in combination with K nearest neighbors (KNN) and support vector machine (SVM) classifiers[J]. Optics & Laser Technology, 102, 233-239(2018).

[16] Yang Y L, Wang L, Ma C H. Quantitative analysis of liquid steel element in LIBS using SVR improved by particle swarm optimization[J]. Laser & Optoelectronics Progress, 57, 053002(2020).

[17] Chen Y, Zhang C, Xiao C Y et al. Study on prediction model of soil cadmium content moisture content correction based on GWO-SVR[J]. Acta Optica Sinica, 40, 1030002(2020).

[19] Dong M R, Wei L P, Lu J D et al. Quantitative analysis of LIBS coal heat value based on K-CV parameter optimization support vector machine[J]. Spectroscopy and Spectral Analysis, 39, 2202-2209(2019).

[20] Wang Z, Afgan M S, Gu W L et al. Recent advances in laser-induced breakdown spectroscopy quantification: from fundamental understanding to data processing[J]. TrAC Trends in Analytical Chemistry, 143, 116385(2021).