中文摘要：

采用太赫兹时域谱（THz-TDS）技术测量了奶粉中三聚氰胺在0.2-1.8 THz频段的吸收谱和折射率谱,同时运用密度泛函理论（DFT）计算了三聚氰胺在太赫兹波段的振动频率,并据此对实验光谱吸收峰进行了指认,计算结果与实验光谱特征峰很好吻合.表明太赫兹时域谱技术对快速测定识别奶粉中三聚氰胺成分具有良好前景.

英文摘要：

The absorption coefficient and refractive index of melamine in the frequency range 0.2 - 1.8 THz were measured with THz time-domain spectroscopy （THz-TDS）. Simultaneously, the density functional theory （DFT） was applied to obtain vibrational frequencies of melamine in the range. The observed vibrational spectras were assigned according to the DFT calculations; and the theoretical calculations were in good agreement with the experimental data. The results show that rapid detection of melamine compositions in milk powder have good prospects by terahertz time-domain spectroscopy technology.