Yueyang Vocational and Technical College

Yueyang, China

Yueyang Vocational and Technical College

Yueyang, China
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Yu X.,Yueyang Vocational and Technical College | Sun D.,Central South University of forestry and Technology | Li X.,University of South China
Journal of Wood Science | Year: 2011

To improve its overall performance, fast-growing poplar was modified using the vacuum-pressure-vacuum impregnation method with a urea-formaldehyde resin-sodium montmorillonite intercalation as the modification solution. The results showed that considerable amounts of urea-formaldehyde resin and montmorillonites entered the poplar tracheid, and some entered the microporous wood. These substances formed bonds with the active groups in timber, causing reduced crystallinity in the amorphous region of the poplar, a decreased level of free hydroxyl, and an enhanced association with hydroxyl and ether bonds. The density, dimensional stability, and mechanical properties of poplar were markedly improved. The best results were obtained with 14% sodium montmorillonite and 20% ureaformaldehyde resin: the bending resistance, compressive resistance, and elastic modulus increased by 19. 37%, 30. 24%, and 50. 06%, respectively. With elevated levels of sodium montmorillonite, the impact toughness and wear rate decreased. © 2011 The Japan Wood Research Society.


Tang Y.,Xiangtan University | Chen H.,Yueyang Vocational and Technical College | Weng C.,Xiangtan University | Tang X.,Xiangtan University | And 4 more authors.
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

A new simple and highly sensitive catalytic kinetic method for the determination of trace amount of FA in food sample has been established. The method was based on the catalytic effect of FA on the oxidation of eosin Y by potassium bromate in present of phosphoric acid. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of eosin Y at 518 nm. Under the optimized experimental conditions, the developed method allowed the determination of FA in the range of 0.03-0.6 μg mL-1 with a good precision, and the limit of detection was down to 0.00988 μg mL -1. The relative standard deviation of five replicate measurements for the determination of FA in concentration 0.12 μg mL-1 was 1.8%. The proposed method was successfully applied to the determination of FA in food directly and satisfactory results were obtained. © 2014 Elsevier B.V. All rights reserved.


Fang Z.-H.,Yueyang Vocational and Technical College | Fang Z.-H.,Hunan University | Lu L.-M.,Hunan University | Zhang X.-B.,Hunan University | And 4 more authors.
Electroanalysis | Year: 2011

A new third-generation biosensor for H2O2 assay was developed on the basis of the immobilization of horseradish peroxidase (HRP) in a nanocomposite film of carbon nanotubes (CNTs)-SBA-15 modified gold electrode. The biological activity of HRP immobilizing in the composite film was characterized by UV-vis spectra. The HRP immobilized in the nanocomposite matrix displayed excellent electrocatalytic activity to the reduction of H2O2. The effects of the experimental variables such as solution pH and working potential were investigated using steady-state amperometry. Under the optimal conditions, the resulting biosensor showed a linear range from 1μM to 7mM and a detection limit of 0.5μM (S/N=3). Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhong B.,Yueyang Vocational and Technical College | Chen R.,Yueyang Vocational and Technical College
Advanced Materials Research | Year: 2012

The essay has solved the optimization problem turning multi-objective problem into a single target by using weighting factor to the use of V-belt driving gear. According to engineering requirements, mechanical vibration test machine has determined the coordination of the various coefficients as a single objective optimization function after considering multiple conflicting incommensurability of the objective function, and combining practical experience and computing experience. Conditions on system requirements and relative constraints have been given in the form of constraint functions. Finally, the overall optimal solution has been calculated with the direct method, and an integrated optimal solution can have different numerical values by calculating it for different project objectives and specific requirements. © (2012) Trans Tech Publications, Switzerland.


Yu X.-C.,Yueyang Vocational and Technical College | Sun D.-L.,Central South University of forestry and Technology
Asian Journal of Chemistry | Year: 2013

Pollution of inorganic acid can be reduced, pectin yield and purity can be increased by using microwave to process orange peels and then adding complex enzyme to extract pectin. The infrared spectrum showed that orange pectin contained a relatively huge amount of carbohydrates, but no protein. The extract technology was optimized by orthogonal experiments at 250 W microwave power, 50 °C microwave heating temperature, 10 min microwave processing time, 1 h single extraction time, buffer pH 4.5, 50 °C enzyme extraction temperature and 0.9 % enzymatic dosage. Enzyme extraction was performed three times. The average yield in orange peel pectin was 22.12 %, which was much higher than the pectin extraction yield using conventional water bath method under the same conditions.


Sun D.-L.,Central South University of forestry and Technology | Yu X.C.,Yueyang Vocational and Technical College | Wang R.,Central South University of forestry and Technology
Asian Journal of Chemistry | Year: 2013

A woodceramics is prepared from liquefied corncob and poplar powder. The basic property of this material is closely correlated to the carbonization temperature and liquefied corncob content. The thermogravimetric analysis indicates that the high liquefied corncob content can decrease weight loss. X-ray diffraction analysis shows that higher carbonization temperature can improve the graphitization degree of this material, but the phase composition is not mainly related to the liquified corncob content. Scanning electron microscopy confirms that the poplar powder is as a natural plant template and the pore of woodceramics partly keeps the native characteristics of the wood with size ranging from 5 to 20 μm. It is porous carbon material with three-dimensional network structure.


Delin S.,Central South University of forestry and Technology | Xianchun Y.,Yueyang Vocational and Technical College | Debin S.,Central South University of forestry and Technology | Rong W.,Central South University of forestry and Technology
Applied Mechanics and Materials | Year: 2012

A woodceramics makes from liquefaction wood and wood powder, the basic property connects with sintering temperature and liquefaction wood content. Thermo gravimetric analysis indicates that higher liquefaction wood content lead to reduce the weight loss. Scanning electron microscopy observation shows that wood powder is as a natural plant template and the basic structure of wood can partly keep. The apparent density increases before about 1100°C, and then decreases as temperature gets further; but the apparent porosity increases continuous; bending strength increases from 8.45 MPa to 11.87 MPa when the liquefaction wood content raises 60%-120%. Meanwhile, elevation of liquefaction wood content and sintering temperature can reduce abrasion loss. © (2012) Trans Tech Publications, Switzerland.


Sun D.L.,Central South University of forestry and Technology | Yu X.C.,Yueyang Vocational and Technical College
Applied Mechanics and Materials | Year: 2013

Discarded wood was liquefied with phenol to prepare the liquefication basic woodceramics (LBW). The effects of sintering temperature on the phase changes had discussed. The Fourier transform infrared (FT-IR) analysis showed that, as sintering temperature rose, the elements of H and O were excluded gradually, as well the circle C-C structure had formed. The X-ray diffraction (XRD) analysis indicated that higher sintering temperature could improve the microcrystal structure. With the temperature increasing, (002) diffraction peak became strong and the diffraction angle 2è became larger, meanwhile, the stacking height of larger plane and the crystallite size increased also. In addition, the distances of interlamination drop drown, and the rank of microcrystal became more regulation and order. But g values which character the degree of graphitization always were less than zero, and the integrated graphite structure had not found, suggesting the LBW was a kind of a difficult graphitization material. © (2013) Trans Tech Publications, Switzerland.


Zhongbo,Yueyang Vocational and Technical College
Advanced Materials Research | Year: 2012

Pressure component of the magnetic base with gray cast iron strength analysis methods and intensity conditions the calculation there are obvious flaws and inadequacies. Test, analysis of this issue, the introduction of the internal friction, calculate and analyze the effective value of the internal friction angle Φ to obtain a more accurate, more in line with the actual strength conditions. © (2012) Trans Tech Publications, Switzerland.


Sun D.,Central South University of forestry and Technology | Yu X.,Yueyang Vocational and Technical College | Liu W.,Central South University of forestry and Technology
Materials and Design | Year: 2012

Biomorphous SiC/Si porous ceramics with laminated structure are prepared from beech veneer and phenolic resin. The preparation involves carbonization under vacuum and reaction with melted silicon to obtain the biomorphous carbide template. X-ray diffraction confirms that the biomorphous SiC/Si porous ceramics are mainly composed of β-SiC, free silicon and residual carbon. Scanning election microscopy observations indicate a laminated structure and 1-10 μm microporous structures, which suggest retention of the native characteristics of the wood. This paper examines mechanical properties of the final composite in relation to the lamination, porous structure, and free silicon content. The bending strength of the ceramics decreases as the apparent porosity increases. The fracture toughness increases initially with apparent density and then decreases. The fracture toughness load-displacement curve presents a step-like pattern, which suggests that the laminated SiC/Si porous ceramics have high fracture toughness. © 2011 Elsevier Ltd.

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