[6] [6] Maeng I, Baek S H, Kim H Y, et al. Feasibility of using terahertz spectroscopy to detect seven different pesticides in Wheat Flour [J]. Journal of Food Protection, 2014, 77(12): 2081-2087.

[7] [7] Seung Hyun B, Heung Bin L, Hyang Sook C. Detection of melamine in foods using terahertz time-domain spectroscopy [J]. Journal of Agricultural and Food Chemistry, 2014, 62(24): 5403-5407.

[13] [13] Dorney T D, Baraniuk R G, Mittleman D M. Material parameter estimation with terahertz time-domain spectroscopy [J]. Journal of the Optical Society of America A, Optics Image Science and Vision, 2001, 18(7): 1562-1571.

[14] [14] Duvillaret L, Garet F, Coutaz J L. Highly precise determination of optical constants and sample thickness in terahertz time-domain spectroscopy [J]. Appl. Opt., 1999, 38(2): 409-415.

[16] [16] Baxter J B, Guglietta G W. Terahertz spectroscopy [J]. Analytical Chemistry, 2011, 83(12): 4342-4368.

[18] [18] Bichara L C, Lanús H E, Nieto C G, et al. Density functional theory calculations of the molecular force field of L-ascorbic acid, vitamin C [J]. Journal of Physical Chemistry A, 2010, 114(14): 4997-5004.