Papers by Author: Peng Chen

Abstract: the experiments set up a roof model with a solar energy heat storage ventilation. According to the actual demands of experiments, through an economic analysis it results the preliminary investment of the solar energy storage ventilationthe system is between 307~367Yuan/m2 by calculating a energy balance in some way and choosing some type of heat storage phase change materials with a suitable quantity to fit for the model.

Abstract: Silicon wafers with different carbon contents have been characterized by Fourier transform infrared spectroscopy technique. An infrared absorption band at 1207cm-1 can be newly observed in the case of carbon content being above 1.7×1017/cm3, whose intensity increases with an increase of carbon concentration in silicon crystal. More interestingly, the 1207cm-1 band cannot be influenced by the long-time annealing in the temperature range of 450-1250oC, suggesting the high thermal stability of this carbon-related defect, which might be related to the presence of silicon carbide in silicon crystals.

Abstract: Cellulose micro/nano fibrils generated from biomass are relative new reinforcing materials for polymer composites, which have potential lightweight and high strength and are renewable. In the present study, the preparation method of extracting cellulose micro/nano fibrils from wood was introduced. After successful disintegration, the morphological characteristics of the wood fibers, purified cellulose fibers, cellulose fibers activated by ultrasonic-wave and cellulose micro/nano fibrils after homogenization treatment, were compared by visual examination and scanning electron microscopy. The results showed that cellulose micro/nano fibrils have been efficiently extracted from wood, which have great potential in the application areas of papermaking, bio-nanocomposites, food, cosmetics/skin cream, medical/pharmaceutical, and so on.

Abstract: In order to improve the decay resistance of wood as the renewable natural material of biological origin, an organic preservative, 3-iodo-2-propynyl butyl carbamate (IPBC), was penetrated into wood matrix by supercritical CO2 as a carrier solvent. And the effectiveness of penetrating IPBC into wood matrix through SC-CO2 was also examined in terms of preservative distribution, leachability resistance of preservative as well as decay resistance of wood. The results indicate that the optimum penetration craft under the adopted conditions was pressure: 19MPa, temperature: 35°C, pressure time: 2.5h and time for releasing pressure: 20min. And under the optimum condition, the mechanical properties of SC-CO2 treated wood were not significantly affected. SEM-EDX analysis indicate that IPBC mainly distributed in wood matrix due to the higher penetration of supercritical CO2 as a carrier solvent, and its leachability was remarkably reduced after such penetration. The decay resistance of SC-CO2 treated wood against fungi attack was improved 90.96% over untreated wood, indicating effective decay resistance of wood after preservative penetration with SC-CO2.

Abstract: In this paper, the production technology of laminated veneer lumber was optimized by using the uniform design method. The effects of production technology, such as the press duration, the press temperature, the press pressure and the adhesive spread, were found statistically significant on some mechanical properties of LVL. So in this paper, the thickness of LVL board was a fixed value, but the press duration, the press temperature and the adhesive spread were variable. The modulus of elasticity (MOE) and static bending strength (MOR) as predicted by the ANN approach and the regression functions were compared with the experimental values. It was shown that the proposed neural network model was able to predict valuable mechanical properties, such as the modulus of elasticity and static bending strength, that would facilitate the development of optimum design of properties for manufacturing high quality materials.