Ultrasonic phase spectrum of reflection coefficient has been used to nondestructively characterize the density,porosity,......

With the vigorous development of national infrastructure construction and public information construction, video surveil......

雷达的接收机信道作为带通滤波器 ,其内部混有噪声 ,因此 ,当用其传输放大脉冲信号时 ,对脉冲相位谱会产生影响 ,使脉冲前后沿发生......