基本: basic; fundamental频率: frequency; rate标准: standard; criterion; benchma ...基本频率: base frequency; basic frequency; elementary-frequency; fundamental frequency; master frequency晶体基本频率: crystal fundamental副频率标准: secondary frequency standard频率标准: fs frequency standard原频率标准: primary frequency standard铷频率标准: rubidium freqnency standard基本频率（或自然频率）: fundamental or natural frequency基本频率指示器: fundamental frequency indicator精确频率标准: precision frequency standard量子频率标准: quantum frequency standard美国频率标准: united states frequency standards一级频率标准: primary frequency standard原子频率标准: atomic frequency standard中央频率标准: central frequency standard氨分子频率标准: ammonia molecular frequency standard国内主振频率标准: national master frequency standard晶体管化频率标准: transistorized frequency standard气体池频率标准: gas-cell frequency standard时间和频率标准: time and frequency standard实验室的频率标准: laboratory standard of frequency实验室频率标准: laboratory frequency standard; laboratory standard of frequency无源原子频率标准: passive atomic frequency standard
