1：Experimental Design and Method Selection:

A methodology using a broad-tuning, rapid-scan external-cavity quantum-cascade-laser (EC-QCL) with shock tube facilities was employed to measure absorption spectra. The Beer-Lambert relation was used to define absorption cross sections.

2：Sample Selection and Data Sources:

Methanol (CH3OH) and ethanol (C2H5OH) were selected as target species. Test gases were prepared by diluting vapor from anhydrous alcohol liquids with argon gas.

3：List of Experimental Equipment and Materials:

Equipment includes a shock tube (Stanford Kinetics Shock Tube), EC-QCL (MIRcat-QT TM), MCT detectors (Vigo System TM PVM-2TE-

4：6), CO2 gas laser (Access Laser Company TM), spectrum analyzer (Bristol Instruments TM 771B-XIR), ZnSe beam splitters and windows, filters (Edmund Optics TM 3 μm long-pass filter, Spectrogon TM 85-5 μm band-pass filter), and gas handling systems. Materials include helium, nitrogen, argon gases (Praxair TM), methanol (Sigma-Aldrich TM, 8% purity), and ethanol (Sigma-Aldrich TM, 5% purity). Experimental Procedures and Operational Workflow:

Test gases were prepared manometrically in a heated mixing tank, introduced into the shock tube, and shocked to create high-temperature conditions. The EC-QCL was tuned rapidly to scan the spectral range, with triggers from pressure transducers. Absorption spectra were collected using detectors, with corrections for wavelength drifts and thermal emissions.

5：Data Analysis Methods:

Absorption cross sections were calculated using the Beer-Lambert law. Uncertainties were assessed for temperature, pressure, and absorbance levels. Spectra were compared with models like HITRAN 2016.