3.443.3° MethyI-PAH 2.5 Aliphatic-to-Aromatic C-H Stretch Band Ratio Calculated for Methyl-PAHs 2.0 1.5 This work:14<A/A4<23,|<A/A>≈1.76 Li draine(2012):A,/A, a 0.68 1.0 Yang et al.(2013)A3.4/A3.3: Methyl-PAH Yang et al. (2013)