久久久久亚洲Aⅴ无码福利_亚洲一本大道av久在线播放_深夜无码一区二区三区_亚洲日本va在线视频

Coal mine gasexplosion underground,roof caving,flooding and otheraccidents have occurred from time to time.How toadvance goodprotection,after theloss to a minimum,how to achieve a betterrescue work,causes the ground totimely understand theundergroundscene of the accident,the implementation of theminerescue workcommand,emergency communicationsystem of coal minesecurity monitoringcan play a crucial role.The traditionalcoal minecommunication systemequipmenthas been using afixedexplosion-prooftelephone,its coverageis small,only callin the fixed-point,anddoes not have mobility,which makesan emergencydispatch commandcould not be completedin the first time,the mainresponsible person can not berushed to the scene to understandanddeal with the emergencyin the firsttime.However,the mine roadwayis a nonfree spaceradio wavesis fundamentalconstraintsin the transmissionof underground laneway,over the yearshas carried on the positive explorationand research of manydomestic and foreign experts and scholarsin this field.This paperuses thelong wave communicationprinciple inunderground mine mobile communicationsystem iswidely used.