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An inherent water-soluble sodium-loaded coal sample was prepared using crown ether for this study. The pyrolysis process of an inherent water-soluble sodium-loaded coal sample and a water-soluble sodium compound-loaded coal sample was researched by thermogravimetric analysis (TGA). Also, the pyrolysis kinetics of the coal samples were analyzed and researched by the distributed activation energy model (DAEM). The results show that the inherent water-soluble sodium is mainly concentrated on coal particles, which further aggravates the degree of the pyrolysis reaction. The presence of sodium can promote the weight loss of coal samples in the preliminary stage of pyrolysis and the thermal condensation stage, block the escape of volatile matter during the main pyrolysis period, and inhibit the process of graphitization of char. The activation energy of pyrolysis increases with the carbon conversion rate, and the presence of sodium can reduce the activation energy under the same carbon conversion rate., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

A dual-band high-precision lightning imaging spectrometer (DHLIS) is designed to capture the fine spectrum of transient lightning. DHLIS improves the theoretical spectral resolution limit to 10 -3 n m and broadens the spectral range to 30-40 nm by employing double echelle gratings in the arms of a spatial heterodyne spectrometer. Four strong and three fine spectral lines are selected to retrieve the temperature of the lightning channel using the Boltzmann plot method. The experimental results indicate that the inversion accuracy of the temperature obtained by inserting fine spectral lines is higher than that by implementation of four strong spectral lines.