MECHANISM OF DEFORMATION AND PRESSURE RELIEF CONTROL OF DYNAMIC GOB-SIDE ENTRY SURROUNDINGS IN FULLY-MECHANIZED CAVING MINING FOR EXTRA-THICK COAL SEAM

Affected by the superposition of working face mining, strong rock pressure phenomena such as rock burst and large deformation easily occur in the gob-side entry when mining extra-thick coal seams.Taking the extra-thick coal seam mining of Caojiatan Coal Mine in Yushen Mining Area as the engineering background, the appearance mechanism of strong min

Risk of spillover and spillback of mosquito-borne viruses in the neotropics, including yellow fever, dengue, Zika (Flaviviridae: Flavivirus), chikungunya, and Mayaro (Togaviridae: Alphavirus) viruses, is highest at ecotones where humans, monkeys, and mosquitoes coexist.With a view to identifying potential bridge vectors, we investigated changes in

Arbitrary manipulation of the temporal and spectral properties of x-ray pulses at free-electron lasers would revolutionize many experimental applications.At the Linac Coherent Light Source at Stanford National Accelerator Laboratory, the momentum phase-space of the free-electron laser driving electron bunch can be tuned to emit a pair of x-ray puls

The finite element analysis is used for click here the static and dynamic analysis of the Z axis brace of PCB CNC drilling machine.With its results of maximum displacement deformation and von Mises stress and modal frequency, the defect of original design was found out.On such bases, a variety of optimization scheme is put forward and the best size