脉冲傅立叶变换核磁共振谱仪 Normal rf pulses are square shaped (in the time domain), their excitation profile(in the quare Sinc frequency domain) is given by A for(0<t<T) A[sin(ot)/(ot)] ts fourier transform. the sinc function(approximation forβ180°) he excitation band width is proportional to the reciprocal of the pulse duration, pulses V(HZ must be short enough to keep the wiggles outside the range of interest. THNMR YANTHNMR YAN 脉冲傅立叶变换核磁共振谱仪 Normal rf pulses are square shaped (in the time domain), their excitation profile (in the frequency domain) is given by its FOURIER transform, the sinc function (approximation for b«180°). The excitation band width is proportional to the reciprocal of the pulse duration, pulses must be short enough to keep the "wiggles" outside the range of interest