[1] . Progress and application of spectral data pretreatment and wavelength selection methods in NIR analytical technique[J]. Progress in Chemistry, 2004, 16(4): 528-542.

[2] Li Hui, Xie Shusen, Lu Zukang et al.. A new model of the light scattering in biological tissue for visible and near infrared region[J]. Acta Optica Sinica, 1999, 19(12): 1661～1666 (in Chinese)
李晖,谢树森, 陆祖康 等. 生物组织的可见光与近红外光散射模型[J]. 光学学报, 1999, 19(12): 1661～1666

[3] Zhao Jiewen, Zhang Haidong, Liu Muhua. Preprocessing methods of near infrared spectra fro simplifying prediction model of surgar content of apples[J]. Acta Optica Sinica, 2006, 26(1): 1136～1139 (in Chinese)
赵杰文,张海东,刘木华. 简化苹果糖度预测模型的近红外光谱预处理方法[J]. 光学学报, 2006, 26(1): 1136～1139

[4] . Non-destructive determinat ion of sugar contents of apples using near infrared diffuse reflectance[J]. Transactions of the CSAE, 2005, 21(3): 162-165.

[5] . . Effect of biological variability on the robustness of NIR models for soluble solids content of apples[J]. Postharvest Biology and Technology, 2003, 28(3): 269-280.

[6] . Kleynen, V. Leemans, M.-F. Selection of the most efficient wavelength bands for “Jonagold” apple sorting[J]. Postharvest Biology and Technology, 2003, 30(1): 221-232.

[7] . Wayan Budiastra, Yoshio Ikeda, Takahisa Nishizu. Optical methods for quality evaluation of fruits (part 2)-prediction of individual sugars and malic acid concentrations of apples and mangoes by the developed NIR reflectance system[J]. J. JSAM, 1998, 60(3): 117-128.

[8] . Steinmetz, J. M. Roger, E. Molto et al.. On-line fusion of color camera and spectrophotometer for sugar content prediction of apples[J]. J. Agric. Engng. Res., 1999, 73(4): 207-216.

[9] . H. S. Peiris, G. G. Dull, R. G. Leffler et al.. Spatial variability of soluble solids or dry-matter content within individual fruits, bulbs, or tubers: implications for the development and use of NIR spectrometric techniques[J]. Hori Science, 1999, 34(1): 114-118.

[10] . Lammertyn, K. Ooms et al.. Prediction of the optimal picking date of different apple cultivars by means of VIS/NIR-spectroscopy[J]. Postharvest Biology and Technology, 2000, 21(3): 189-199.

[11] . Lammertyn, Ann Peirs, Josse De Baerdemaeker et al.. Light penetration properties of NIR radiation in fruit with respect to non-destructive quality assessment[J]. Postharvest Biology and Technology, 2000, 18(1): 121-132.

[12] . Guyer, Randolph M. Beaudry. Determination of firmness and sugar content of apples using near-infrared diffuse reflectance[J]. J. Texture Studies, 2000, 31(6): 615-630.

[13] . Park, J. A. Abbott, K. J. Lee et al.. Near-infrared diffuse reflectance for quantitative and qualitative measurement of soluble solids and firmness of delicious and Gala apples[J]. Transactions of the ASAE, 2003, 46(6): 1721-1731.

[14] . Nrgaard, A. Saudland, J. Wagner et al.. Interval partial least squares regression (iPLS): A comparative chemometric study with an example from near-infrared spectroscopy[J]. Applied Spectroscopy, 2000, 54(3): 413-419.

[15] . Leardi, A. Lupiáez, González. Genetic algorithms applied to feature selection in PLS regression: how and when to use them[J]. Chemometrics and Intelligent Laboratory Systems, 1998, 41(2): 195-207.

[16] . Leardi, L. Nrgaard. Sequential application of backward interval PLS and genetic algorithms for the selection of relevant spectral regions[J]. J. Chemomelrics, 2004, 18(11): 486-497.

[17] . Leardi. Application of genetic algorithm-PLS for feature selection in spectral data sets[J]. J.Chemometrics and Intelligent Laboratory Systems, 2000, 14(5): 643-655.