简介:ThelowresistancePTCceramicthermistormaterialwithexcellenteleectricalpropertiesaresuccessfullyfabricatedbyrawmaterialsatindustrialrangemadeinourcountryonthestudyofitscompositionexpressionandfabricationprocessbyusingtheadditionofNb,La,Y,Ta,microstructureregulatorBNandASTLphase.Thecompositionanditsfabricationmethodarestudied.TherelationofelectricalpropertiesofthePTCceramicmaterialtoitscompositionexpressionanditsrelatedelectricalpropertiesarediscussed.
简介:摘要投用地面主通风机可以根据掘进头数量增加情况,实时变频调节矿建施工过程中巷道风量及风压并可实现多头掘进,提前投用主通风机不仅节约资金,减少了安装风门和局部通风机的工序,而且使用冻结方法施工风井风道,确保了通风机风道快速高效的施工,为矿井主通风机提前投入使用及加快矿井建设提供了保障。