Publications by authors named "Shi-Lai Yi"

For better determination of the chemical components in the Puer black tea, Fourier transform infrared spectroscopy was used for obtaining vibrational spectra of Puer black tea at different aging time. Fourier transform infrared (FTIR) spectra indicated that the chemical components had change in Puer black tea at different aging time. The leaf of Puer black tea was a complex system, its Fourier transform infrared spectrum showed a total overlap of each absorption spectrum of various components.

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Existing methods for the identification of pummelo cultivars are usually time-consuming and costly, and are therefore inconvenient to be used in cases that a rapid identification is needed. This research was aimed at identifying different pummelo cultivars by hyperspectral imaging technology which can achieve a rapid and highly sensitive measurement. A total of 240 leaf samples, 60 for each of the four cultivars were investigated.

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The effective region was segmented from the hyperspectral image of citrus leaf by threshold method with the average spectrum extracted and used to describe the corresponding leaf. Based on the different spectral pre-processing methods, the prediction models of three photosynthetic pigments (i. e.

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Article Synopsis
  • The study used Fourier transform infrared (FTIR) spectroscopy to analyze the diversity of spring leaf samples from seven different varieties of Citrus sinensis (L.) Osbeck.
  • Results indicated that while the FTIR spectra showed similar absorption peaks primarily due to cellulose and polysaccharides, there were differences in peak shapes and absorption intensities, especially noticeable between 1,500 and 700 cm(-1).
  • Hierarchical cluster analysis (HCA) of the second derivative spectra revealed that the citrus varieties could be classified based on their genetic relationships, demonstrating the effectiveness of FTIR spectroscopy and HCA for rapid identification and classification of citrus varieties.
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Olinda valencia orange leaves dry powder-like were taken as sample, and chemical analysis combined with technology of visible near-infrared spectroscopy (Vis/NIRS) was used, through the treatment process of second derivative spectrum of samples of the original spectrum and denoising (Noise). Meanwhile, method of partial least squares (PLS) and cross-validation were used to establish maths model of Zn concentration which applying band combination composited by 400-500 and 1201-1300 nm of characteristic wavelength band. The coefficient of establishing models is 0.

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The purpose of our study is to study the relationship between the reflective spectrum of fruit and the internal quality of the orange fruit and find the suitable mark spectrum that can synchronously measure the several fruit quality index at same time to lay a foundation for the development of a rapid and nondestructive field fruit quality analysis technique by analyzing the visible-near infrared spectrum. Mature Hamlin orange (Citrus sinensis (L)cv. Hamlin sweet orange) fruits were individually mensurated for their reflective spectrum by using FieldSpec-HH spectrometer and for their contents of total soluble solid (TSS), citric acid and vitamin C (Vc) by chemistry analysis.

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The relationship between the spectrum characteristics and nitrogen content of soils in citrus orchard of the Three Gorges Reservoir Area was studied by analyzing the visible-near infrared spectrum. The results showed that the soil reflectivity in creased lineally as the wavelength increases across the visible spectrum and reached a stable plateau in the short wavelength near-infrared region (780-1750 nm)without much fluctuation. In the long wavelength near-infrared region (1750-2400 nm) the reflec tivity of the soils was higher with higher fluctuation.

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