The real - time evaluation and control system of short circuit dual - frequency transfer 短路双频率过渡实时评价控制系统
2.
Dual - frequency motor 双频率电动机
3.
Proper vibration frequency and two amplitudes for different soil and layer depth 适宜的双频率值和双振幅值，适合不同的土壤和铺层厚度。
4.
Two important applications are as band - pass radomes and as sub reflectors for dual frequency reflector antenna system 其最主要的两个应用是作为带通滤波器的天线罩和用作双频率反射天线系统的副反射器。
