噪声测向声纳
noise direct listening sonar
等效噪声双端口
equivalent noise two-port
视觉噪声双视力表
Visual noise dual acuity chart
双耳声级差
Interaural level difference
ILD
双向双从蹄式制动器
dual two trailing shoe brake
双向双领蹄式制动器
dual two leading shoe brake
双向双偏注入
Double crossed directions
双向双套冗余
BDR Bi – Duplexed Redundancy
BDR Bi C Duplexed Redundancy