短語詞組短語failure e rate curve 故障率曲線shielding failure flashover rate 繞擊閃絡(luò)率failure -rate average function 失效率平均函數(shù)failure analysis rate 衰壞率high failure -rate 故障率高failure intensity rate 故障強度率failure recovery rate 故障恢復率shielding failure outage rate 繞擊跳閘率 返回 failure rate