کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5428458 | 1508677 | 2014 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Measurements and modeling of long-path 12CH4 spectra in the 4800-5300 cmâ1 region Measurements and modeling of long-path 12CH4 spectra in the 4800-5300 cmâ1 region](/preview/png/5428458.png)
- 2725 experimental line positions were retrieved and modeled to 0.004Â cmâ1.
- 1764 experimental line intensities were modeled to 7.3%.
- A line list of assigned features was made with intensities at 296Â K.
- The integrated intensities matched variational calculations to within 5%.
A new study of 12CH4 line positions and intensities was performed for the lower portion of the Tetradecad region between 4800 and 5300Â cmâ1 using long path (1603Â m) spectra of normal sample CH4 at three pressures recorded with the Fourier transform spectrometer in Reims, France. Line positions and intensities were retrieved by least square curve-fitting procedures and analyzed using the effective Hamiltonian and the effective Dipole moment expressed in terms of irreducible tensor operators adapted to spherical top molecules. An existing spectrum of enriched 13CH4 was used to discern the isotopic lines. A new measured linelist produced positions and intensities for 5851 features (a factor of two more than prior work). Assignments were made for 46% of these; 2725 experimental line positions and 1764 selected line intensities were fitted with RMS standard deviations of 0.004Â cmâ1 and 7.3%, respectively. The RMS of prior intensity fits of the lower Tetradecad was previously a factor of two worse. The sum of observed intensities between 4800 and 5300Â cmâ1 fell within 5% of the predicted value from variational calculations.
Journal: Journal of Quantitative Spectroscopy and Radiative Transfer - Volume 138, May 2014, Pages 116-123