Entity

Time filter

Source Type


Yu X.-C.,Yue Yang Vocational and Technical College | Sun D.-L.,Central South University of forestry and Technology | Li X.-S.,University of South China
Asian Journal of Chemistry | Year: 2012

Ultrasound-enhanced supercritical CO 2 was used to extract the essential oil of masson pine. The extraction technology was optimized through orthogonal experiments. The results showed that a good outcome can be achieved with an extraction pressure of 18 MPa, a temperature of 60 °C, a time of 90 min, a CO 2 flow rate of 12 kg h -1, an ultrasonic power of 250 W and an ultrasonic frequency of 22 KHz. Using these parameters, the average yield of essential oil was 88.12 %. GC-MS analysis showed that the ingredient with the highest content of 44.42 % was longifolene in the essential oil of masson pine wood, followed by a-pinene and caryophyllene, with contents of 28.17 and 6.03 %, respectively.


Yu X.-C.,Yue Yang Vocational and Technical College | Sun D.-L.,Central South University of forestry and Technology | Li X.-S.,University of South China | Yi X.-J.,Yue Yang Vocational and Technical College
Asian Journal of Chemistry | Year: 2012

Furfural was prepared through the combined hydrolysis of rice hull with cellulase and SO 4 2--TiO 2 clay solid acid. An optimization analysis of the key factors was carried out with the methods of orthogonal experimentation and response surface analysis. The orthogonal experiment result of enzymolysis showed that the average pentose content was 17.54 g L -1 under the following conditions i.e., granularity of raw materials, 120 grit; solid-to-liquid ratio, 1:13; zymohydrolysis temperature, 55 °C; enzymolysis time, 8 h and amount of enzyme solution, 30 U g -1 dry rice hull powder. The response surface analysis of the preparation of furfural with solid acid showed that the yield of furfural was 70.87 % under a reaction temperature of 152 °C, reaction time of 125 min and 6.1 % of solid acid. Compared with the technology that does not use cellulase hydrolysis, the yield of furfural was increased by 18.41 %.


Sun D.,Central South University of forestry and Technology | Yu X.,Yue Yang Vocational and Technical College
Wood and Fiber Science | Year: 2011

This study introduces poplar veneer ultrasonic-assisted dyeing. Response-surface methodology was adopted to perform optimum analysis of effects of ultrasonic dyeing on poplar veneer. Results demonstrated that ultrasound increased dye uptake under optimal conditions (210-W ultrasonic power, 57-min assisted dyeing time, and 30-kHz ultrasonic frequency using a dye concentration with mass fraction of 0.52% at 72°C). Under these optimal conditions, dye uptake can reach 42.4%. Compared with nonultrasonic dyeing technologies, ultrasonic dyeing technology for poplar veneer developed in this study increased dye uptake 11.2%. © 2011 by the Society of Wood Science and Technology.


Sun D.-L.,Central South University of forestry and Technology | Yu X.-C.,Yue Yang Vocational and Technical College | Sun D.-B.,Central South University of forestry and Technology
Wood and Fiber Science | Year: 2010

Laminated wood-ceramics were created from beech veneer by impregnation with phenol formaldehyde resin and airtight sintering. The resulting laminated biocarbon material exhibited a clearly layered structure and partially preserved microstructural characteristics of normal wood. Laminated structure and airtight sintering techniques significantly affected basic material properties. Carbon yield can increase and sintering cost can decrease through these methods. The material treatments used generate porosity, density, and volumetric shrinkage properties that are different from composites that are vacuumsintered. Its layered structure is associated with the stacking of veneers. The fracture toughness increases to 0.6-1.2 MPa-m1/2 because of the laminated structure, and the material exhibits a progressive failure behavior. © 2010 by the Society of Wood Science and Technology.


Yu X.-C.,Yue Yang Vocational and Technical College | Yu X.-C.,Central South University of forestry and Technology | Sun D.-L.,Central South University of forestry and Technology | Sun D.-B.,Central South University of forestry and Technology | And 2 more authors.
Wood Science and Technology | Year: 2012

Woodceramics is made from bamboo powder and epoxy resin. Analysis with X-ray diffraction (XRD) shows that with an increase in sintering temperature, the degree of graphitization increases. Scanning electron microscopic (SEM) analysis also indicates that bamboo powder exists in the composite as natural plant template. The study suggests that both sintering temperature and epoxy resin content have significant effects on its basic properties. Compressive strengths of woodceramics increase as sintering temperature rises but decrease as temperature rises to 1,000°C, and Young's modulus rises along with higher resin content. Its density increases as sintering temperature rises but decreases as temperature rises further to 1,300°C. The apparent porosity tends to increase with increasing sintering temperature. In addition, elevation of resin content and sintering temperature can reduce electrical resistance, and sintering temperature has greater impact. © 2010 Springer-Verlag.

Discover hidden collaborations