测()压力时,则严禁沾有油脂,以确保安全生产 ["A、氨气","B、氧气","C、氮气","D、二氧化碳"]
测量氨气压力必须采用()弹簧管 ["A、不锈钢","B、铜","C、铝","D、锡"]
1bar=()Pa. ["106","103","105","103"]
1BAr=()psi ["A、0.7×103","B、0.069","C、14.5","D、1.02"]
1psi=()BAr ["A、0.7×103","B、0.069","C、14.5","D、1.02"]
计算题:有一根1GJ120/25导线,单位长度重量为526.6kg/km,计算直径d=15.74mm,计算截面积A=146.73mm2。在冰雪天最大覆冰厚度达50mm,试分别求出导线自重比载g1,冰重比载g2及垂直总比载g3。