frequency code频率码frequencyn.频繁；频率frequency measurement resolution测频分辨率frequency selective compensation选择性谐波补偿frequency co-occurrence matrix频率共生矩阵frequency shift keying telegraph移频键控电报通信frequency decomposing technology分频解释frequency-dependent preference频率依赖嗜好frequency modulation engineering调频工程frequency-variable locomotives变频机车frequency discriminating circuit鉴频电路Frequency fi-linearity E curve频率fi一线性度E曲线