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Xu L.,Anyang University, China | Deng D.-H.,Anyang University, China | Cai C.-B.,Chuxiong Normal University
Journal of Agricultural and Food Chemistry | Year: 2011

Fourier transform infrared (FTIR) spectroscopy combined with chemometric multivariate methods was proposed to discriminate the type (unfermented and fermented) and predict the age of tuocha tea. Transmittance FTIR spectra ranging from 400 to 4000 cm -1 of 80 fermented and 98 unfermented tea samples from Yunnan province of China were measured. Sample preparation involved finely grinding tea samples and formation of thin KBr disks (under 120 kg/cm 2 for 5 min). For data analysis, partial least-squares (PLS) discriminant analysis (PLSDA) was applied to discriminate unfermented and fermented teas. The sensitivity and specificity of PLSDA with first-derivative spectra were 93 and 96%, respectively. Multivariate calibration models were developed to predict the age of fermented and unfermented teas. Different options of data preprocessing and calibration models were investigated. Whereas linear PLS based on standard normal variate (SNV) spectra was adequate for modeling the age of unfermented tea samples (RMSEP = 1.47 months), a nonlinear back-propagation-artificial neutral network was required for calibrating the age of fermented tea (RMSEP = 1.67 months with second-derivative spectra). For type discrimination and calibration of tea age, SNV and derivative preprocessing played an important role in reducing the spectral variations caused by scattering effects and baseline shifts. © 2011 American Chemical Society.

Shen G.,University of Science and Arts of Iran | Cai C.,Chuxiong Normal University | Yang J.,University of Science and Arts of Iran
Electrochimica Acta | Year: 2011

A novel electrochemical immunosensor based on gold-hydroxyapatite nanocomposite-chitosan film has been developed for the detection of prostate-specific antigen. The large surface area of the gold-hydroxyapatite nanocomposite and the porous morphology of chitosan allowed high antibody loading without the loss of bioactivity. The stepwise modification of the electrode was characterized with cyclic voltammetry. Different parameters, including the pH of a supporting electrolyte, the size of the gold nanoparticles, and the antibody concentration were optimized. Under the optimal conditions, the electrochemical immunosensor reliably detected prostate-specific antigen at concentrations from 3.5 to 30 ng/mL with a detection threshold of 2.6 ng/mL. The prepared biosensor was used to assay prostate-specific antigen in human serum samples, and the results were in good agreement with those obtained by enzyme-linked immunosorbent assays. The reported immunosensor exhibits rapid detection, good reproducibility, high sensitivity, specificity, and stable performance. The proposed strategy can be extended for the development of other biosensors. © 2011 Elsevier Ltd.

Huang Y.,Chuxiong Normal University
Nonlinear Dynamics | Year: 2013

With the aid of the known Bäcklund transformation, starting from some given traveling solutions, we consider new exact no-traveling wave solutions to the Liouville equation, and a series of breather soliton solutions, doubly periodic solutions, two-soliton solutions as well as periodic-soliton solutions are obtained. © 2012 Springer Science+Business Media Dordrecht.

Huang Y.,Chuxiong Normal University
Nonlinear Dynamics | Year: 2014

By means of the known Darboux transformation, starting from some stationary wave solutions, we construct a large number of new explicit multiple waves solutions to the Korteweg-de Vries equation, including stationary periodic-soliton solutions, stationary soliton-periodic solutions, doubly periodic solutions, triply periodic solutions, as well as two- and three-soliton solutions. © 2014 Springer Science+Business Media Dordrecht.

Qin H.-F.,Chuxiong Normal University
Research Journal of Applied Sciences, Engineering and Technology | Year: 2012

This study analyzes telecom owe churn customers. Firstly, use the technology of OLAP to analyze the whole theme of the loss of arrears. Then, adopting cluster analysis analyzed consumer behavior (traffic, consumption amount, owed amount) before churn of the churn customer, age and in the net time and explaining the cluster. Finally, using the decision tree analyze the discrete variable and draws the conclusion. © Maxwell Scientific Organization 2012.

Si M.Z.,Chuxiong Normal University | Kang Y.P.,Chuxiong Normal University | Liu R.M.,Chuxiong Normal University
Applied Surface Science | Year: 2012

Silver nanoparticles were prepared by an electrolysis method. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to detect the morphology of these particles. Based on this high active surface enhanced Raman scattering (SERS) substrate, three kinds of azo-dye molecules (Methyl Yellow, Methyl Red and Sudan Red 1) were carefully studied. Using the Gaussian'98 software, we gained the calculation result of these three kinds of azo-dye molecules, and found that the calculation results had good concordance with the experimental one. The detection limit of azo-dye molecules on the silver nanoparticles can go down to 10 -5 mol/l, which indicated that these particles were an active SERS substrate. © 2012 Published by Elsevier B.V. All rights reserved.

Chen Y.H.,Chuxiong Normal University
Monthly Notices of the Royal Astronomical Society | Year: 2016

Three groups of DAV star models are evolved with time-dependent element diffusion by WDEC. The core compositions of these models are directly from white dwarf models evolved by MESA, which are results of thermonuclear burning. Based on these DAV star models, we try to study the dispersion of period spacing. The thickness of hydrogen atmosphere can seriously affect the deviation degree of minimal period spacings. The minimal period spacings dominate the dispersion of period spacing. The thinner the hydrogen atmosphere, basically, the more dispersive the period spacing. Standard deviations are used to analyse the dispersion of period spacing. Studying the dispersion of period spacing on a DAV star KUV03442+0719 preliminarily, we suggest that log(MH/M*) is from -8.5 to -5.5. In addition, modes partly trapped in C/O core are found based on those DAV star models. The identified modes and average period spacings indicate that KUV03442+0719 may be the first star to 'observe' modes partly trapped in C/O core. © 2016 The Authors.

Chai Y.-P.,Chuxiong Normal University
Proceedings 2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011 | Year: 2011

In order to adapt to the unreliable internet environment, the secret image sharing scheme must be able to recover the secret image when some shadows are lost, and the shadows shouldn't attract the attacker's attention when they are transmitted in the internet. Using (t, n)-threshold and steganography could realize the aims mentioned above. This article revised the wrong points in [13] and improved it. The new scheme utilized (t, n)-threshold to share the secret image and embedded the produced n shadows into different cover images, any t out of n shadows can reveal the original secret image, and the cover images could be reconstructed with limited distortion. The experimental results show that the proposed scheme is feasible and effective. © 2011 IEEE.

Xu D.,Chuxiong Normal University
ICIC Express Letters, Part B: Applications | Year: 2012

This paper is concerned with the controllability and observability for a class of general linear time-varying impulsive systems. The solution of such impulsive systems is given by using variation of parameters. Meanwhile, the sufficient conditions for state controllability and state observability of such systems are established. © 2012 ISSN 2185-2766.

Wang H.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Li H.,Chuxiong Normal University | Fang W.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Applied Optics | Year: 2014

The optimization problem of an absolute radiometer's timing parameters is investigated for comparison experiments of Total Solar Irradiance Monitor (TSIM). Comparison experiments were performed to establish the TSIM's contact with other space radiometers for measuring total solar irradiance (TSI). Since the comparison experiments had to be performed on a tight schedule under the impact of weather conditions, the measurement parameters for the comparison experiments were selected carefully using optimized solutions of timing parameters. The optimized solutions were identified by a genetic algorithm (GA) based on a thermal model of an absolute radiometer. The thermal model includes terms of heat radiation, air conduction, etc. Fitness value function and constraints of GA are constructed using the thermal model. The experimental results indicate that the selected measurement parameters are sufficient to implement accurate calibration of TSI, providing more opportunities for solar observation. © 2014 Optical Society of America.

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