Abstract Various elements in air are relatively stable, but may change a lot under combustion, especially in enclosed spaces. Laser-induced breakdown spectroscopy (LIBS) is applied to real-time in situ detection of air, exhalation and smoke from burning paper, cigarettes and mosquito coils indoors. Combined with SVM and BP-ANN, which are utilized to the classification, source tracing achieves good results. Besides, PCA is used in the exploratory data analysis and dimensionality reduction. In the spectrum of exhalation, the C characteristic peak and CN molecular band could be clearly observed, from which frequency of breathing was inferred. Differences between spectra from the same burning sample are discussed, showing some issues of smoke monitoring. In addition, vibrational and rotational temperatures of CN radical were calculated by simulating the CN molecular band in the spectrum.

中文翻译：

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人呼气及室内不同燃烧烟雾的实时原位溯源

摘要 空气中的各种元素相对稳定，但在燃烧时会发生很大变化，特别是在封闭空间内。激光诱导击穿光谱 (LIBS) 用于实时原位检测室内燃烧纸张、香烟和蚊香产生的空气、呼气和烟雾。结合用于分类的SVM和BP-ANN，溯源取得了良好的效果。此外，PCA 用于探索性数据分析和降维。在呼气光谱中，可以清楚地观察到C特征峰和CN分子带，由此推断呼吸频率。讨论了来自同一燃烧样品的光谱之间的差异，显示了烟雾监测的一些问题。此外，