Ga2O3 is being actively explored for high-power and high-temperature electronics, deep-ultraviolet optoelectronics, other applications. Efficient n-type doping of has been achieved, but p-type faces fundamental obstacles due to compensation, deep acceptor levels, the polaron transport mechanism free holes. However, aside from achieving conductivity, plenty opportunity exists engineer position F...

Abstract. Gaseous pollutants at the ground level seriously threaten urban air quality environment and public health. There are few estimates of gaseous that spatially temporally resolved continuous across China. This study takes advantage big data artificial-intelligence technologies to generate seamless daily maps three major ambient pollutant gases, i.e., NO2, SO2, CO, China from 2013 2020 a ...

Aiming at the gas over-run problem in upper corner of “U-type ventilation” end-mining working face multi-source goaf #15 coal seam Phoenix Mountain Mine, site survey and numerical simulation methods were adopted, which showed that maximum caving zone height is 14.87 m, fissure 51.63 m. On this basis, control scheme “U+ omni-directional large-diameter high-level borehole along roof strike” was f...

Surface movement under the combined mining of open-pit and underground caving is main problem affecting safe efficient mining. Taking Dahongshan Iron Mine as an example, a mechanical model for calculating surface range was established to reveal mechanism. The topography, zone, gravel filling zone depth were considered, principal stress calculated. Based on model, relationship between subsidence...

The recovery of top coal in the caving face directly impacts efficiency mining resources. geological conditions and parameters are well known to be significant influences on coal. This study focused 9-301 working face, which is located a thick seam with large dip angle. seam’s angle, direction, mode interval were analyzed using PFC2D simulation. Field trials also carried out. results numerical ...