Li-hong Tan

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Polysaccharide extraction from Dipsacus asperoides roots (DAP) was proved to possess strong antioxidant activities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-Azobis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities, inhibiting β-carotene bleaching and strong reducing power. Cell assay demonstrated that the crude DAP(More)
In this study, volatile oils of six Hawk tea varieties were studied for their chemical composition, antioxidant and antimicrobial activities to screen the most suitable botanical origins of Hawk tea. A total of 72 components were separated and identified from the six oils. The major constituents of the volatile oils were: α-pinene, camphene, limonene,(More)
Visible and near-infrared reflectance spectroscopy (Vis-NIRS) was applied to non-invasively measurement of water content in engine lubricant. Based on measured spectra, several spectral calibration algorithms were adopted to improve accuracy and simply calculation. Principal component analysis (PCA) and successive projections algorithm (SPA) were separately(More)
Visible and near-infrared (Vis-NIR) spectroscopy was applied to identify brands of car wax. A total of 104 samples were obtained for the analysis, in which 40 samples (calibration set) were used for model calibration, and the remaining 64 samples (prediction set) were used to validate the calibrated model independently. Linear discriminant analysis (LDA)(More)
A new method was developed to fast discriminate brands of brake fluid by means of visual-near infrared spectroscopy. Five different brands of brake fluid were analyzed using a handheld near infrared spectrograph, manufactured by ASD Company, and 60 samples were gotten from each brand of brake fluid. The samples data were pretreated using average smoothing(More)
A classification system for analytical methods was developed for the first time to determine the presence of aflatoxins B1, B2, G1 and G2 in traditional Chinese medicines (TCMs) based on different matrix types using ultra-performance liquid chromatography-tandem mass spectrometry. A useful characteristic of the approach was that the TCMs could be(More)
Visible and near infrared (Vis/NIR) spectroscopy was applied for the fast determination of dynamic viscosity of automobile lubricant. One hundred fifty samples from 5 brands were collected for Vis/NIR spectral scanning. Partial least squares (PLS) analysis was applied as calibration method after preprocessing stage as well as a way to extract the first 6(More)
The main objective of this paper is to determine the water content of automobile lubricant based on the near-infrared (NIR) spectra collected and to observe whether NIR spectroscopy could be used for predicting water content. Least square support vector machine (LS-SVM), back-propagation neural networks (BPNN) and Gaussian processes(More)
The performance and influence of near-infrared spectroscopy with different resolutions for brand discrimination of differential oil was studied. Spectral data with resolutions of 4, 8, 16 and 32 cm(-1) were collected, and 10522.28-4443.425 cm(-1) spectra were analyzed after the removal of the absolute noises. The principal component analysis (PCA) of the(More)
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