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Research into a gas sensing material with excellent performance to detect or remove toxic phosgene (COCl 2 ) is of great significance to environmental and biological protection. In the present work, the adsorption performance of COCl 2 on pristine phthalocyanine (Pc) and metal-decorated Pc (MePc, Me = Cu, Ga, and Ru) monolayers was studied by first-principles calculations. The results show that the absorption process of COCl 2 on pristine Pc and CuPc both belong to physisorption, indicating that they are not suitable gas sensing materials for COCl 2 . When Pc sheets are decorated by Ga and Ru atoms, the adsorption of COCl 2 is changed into chemisorption, and the corresponding adsorption energies are −0.57 and −0.50 eV for GaPc and RuPc, respectively. The microcosmic mechanism between COCl 2 and adsorbents (GaPc, RuPc) was clarified by the analysis of the density of states, the charge density difference, and the Hirshfeld charge. In addition, the COCl 2 adsorption results in a significant conductivity variation of the RuPc monolayer, demonstrating it exhibits a high sensitivity to the COCl 2 molecule. Meanwhile, quick desorption processes were noticed at various temperatures for the COCl 2 /RuPc system. Consequently, the RuPc monolayer can be considered as a potential candidate for phosgene sensors because of the moderate adsorption strength, high sensitivity, and fast desorption speed.

The hydrochlorination process is a necessary technological step for the production of polycrystalline silicon using the Siemens method. In this work, the adsorption behaviors of silicon tetrachloride (SiCl 4 ), silicon dichloride (SiCl 2 ), dichlorosilane (SiH 2 Cl 2 ), trichlorosilane (SiHCl 3 ), HCl, and H 2 on the Si(100) surface were investigated by first-principles calculations. The different adsorption sites and adsorption orientations were taken into account. The adsorption energy, charge transfer, and electronic properties of different adsorption systems were systematically analyzed. The results show that all of the molecules undergo dissociative chemisorption at appropriate adsorption sites, and SiHCl 3 has the largest adsorption strength. The analysis of charge transfer indicates that all of the adsorbed molecules behave as electron acceptors. Furthermore, strong interactions can be found between gas molecules and the Si(100) surface as proved by the analysis of electronic properties. In addition, SiCl 2 can be formed by the dissociation of SiCl 4 , SiH 2 Cl 2 , and SiHCl 3 . The transformation process from SiCl 4 to SiCl 2 is exothermic without any energy barrier. While SiH 2 Cl 2 and SiHCl 3 can be spontaneously dissociated into SiHCl 2 , SiHCl 2 should overcome about 110 kJ/mol energy barrier to form SiCl 2 . Our works can provide theoretical guidance for hydrochlorination of SiCl 4 in the experimental method.

The Ordos Basin contains abundant coal resources in the Upper Paleozoic strata. They are shallowly buried or exposed in the periphery of the basin, forming recoverable coal mines and coalbed methane resources. For the deeply buried coal seams of the basin, however, due to complex changes and difficult mining, less attention was paid before. In recent years, with the exploitation of tight gas related to coal source rocks, a large amount of drilling and seismic data has been accumulated in the southeastern Ordos Basin, which makes it possible to study the distribution change and factors controlling Upper Paleozoic coal seams. Delineation of deep coal development and distribution is an important basis for coal, coalbed methane and related tight gas resources in the Upper Paleozoic. We use core, logging and seismic data to analyze the coal geophysics, thickness variation, paleotopography and sedimentary facies in the southeastern Ordos Basin. The lower part of the Shanxi Formation (Fm.) and the upper part of the Taiyuan Fm. in the southeastern part of the basin are characterized by low natural gamma ray, low density, high resistivity and high sonic logging values. As the coal velocity is very low and alternates with the high-velocity Taiyuan Fm. and Ordovician limestones, the two sets of coals below and above the Taiyuan limestones form an extremely strong-amplitude reflection in the seismic profile. The two sets of coals are cumulatively 1–10 m thick, averaging 2.4 m, and 4 m is the maximum induvial thickness. The individual coal seams thicker than 2 m cover an area of approximately 2500 km2, and the burial depths of the coal seam range from 2500 to 3000 m. The thick coal seams of the Taiyuan Fm. are mainly distributed proximally in the Ordovician paleokarst depression, while the Ordovician paleokarst depression without incised origin was deposited by distal coeval limestone rocks. There is a complementary relationship between the coal seams and the thickened zone of distributary channel sandstone in the Shanxi Fm.

Due to the influence of electromagnetic force, the running GIS gas (insulated switchgear) will produce a certain vibration frequency. The other factors, such as resonance, disturbance of internal gas, bring abnormal vibration to the GIS shell. Because of the bad effects followed, the components of GIS can be damaged to the leakage which will lead to power failure in serious cases. In this paper, the vibration analysis of a 1000kV UHV substation 500kV area GIS is carried out. The vibration frequency of the GIS equipment was obtained by field vibration detection, and through the finite element modal analysis, we got the natural frequency and modal shape. It was found that the vibration frequency of the GIS shell is normal reportedly, and the possibility of resonance is ruled out.