Two activated carbons with controlled pore size were prepared from Eucalyptus wood by physical activation with carbon dioxide, giving the BET surface area and pore volume of738 m2/g and0.39 cm3/g, and921 m2/g and0.53 ...Two activated carbons with controlled pore size were prepared from Eucalyptus wood by physical activation with carbon dioxide, giving the BET surface area and pore volume of738 m2/g and0.39 cm3/g, and921 m2/g and0.53 cm3/g for the carbon sample AC1 and AC2, respectively. These activated carbons were then used to remove the residual dye left after the silk-dyeing process. The dye solution used for adsorption study was a cationic aluminium dye complex of [Al(brazilein)2]+ derived from a mixture of alum and extract of the heartwood of Ceasalpinia sappan Linn., with initial dye concentration of 220 mg/l. Effects of adsorbent dosage, adsorption time and temperature in the range of 25℃40℃ on dye adsorption were investigated. It was found that the adsorption kinetics of this dye complex was best described by the pseudo-second order model. Adsorption isotherms of this dye complex were well fitted by Langmuir isotherm equation. The adsorption capacities for the uptake of this dye complex at 25℃, 30℃ and 40℃ were 718.7, 1240.4 and 1139.5 mg/g and 1010.5, 1586.1 and 1659.0 mg/g for carbon sample AC1 and AC2, respectively. From these results, it can be concluded that activated carbon containing a higher proportion of mesopores gave better dye removal efficiency, emphasizing the fact that a proper pore size distribution of carbon adsorbent is crucial for the effecttive removal of relatively large size of the dye molecules. Thermodynamic parameters, including free energy, enthalpy and entropy of adsorption, were also determined. The adsorption enthalpies for the removal of this dye complex of AC1 and AC2 were 105.3 and 55.6 kJ/mol, respectively, indicating that the adsorption is an endothermic process. It was found that the adsorption of this dye complex is spontaneous at the temperatures under investigation.展开更多
Three concentrations （2.8%, 2.0%, 1.2%） of Ammoniacal Copper Quaternary （ACQ） was selected to treat Lodgepole pine wood for evaluating ACQ treatment on mechanical properties of blue-stained wood. The bending modul...Three concentrations （2.8%, 2.0%, 1.2%） of Ammoniacal Copper Quaternary （ACQ） was selected to treat Lodgepole pine wood for evaluating ACQ treatment on mechanical properties of blue-stained wood. The bending modules of elasticity （MOE）, modules of rupture （MOR）, toughness and shearing strength parallel to grain on tangential surface, are tested according to the criteria GB1927-1943-91. Non-treated sample were also tested according to the same procedure. The results showed that the three groups specimen impregnated by different concentrations of ACQ solution met the AWPA standard 2003 of America （UC4A 6.4g/cm^3）. There were significant difference of toughness between treated wood and non-treated wood （p=0.01）, but there were no statistically significant differences among three concentrations in terms of toughness, and toughness of treated wood was approximately 20% lower than non-treated. MOR, MOE as well as sheafing strength parallel to grain were found to be not significantly different between treated wood and non-treated one, and there were no statistically significant difference among three concentrations of ACQ too. Toughness, MOR, MOE and sheafing strength parallel to grain increased with decrease of concentration of ACQ, but they were hardly affected by ACQ preservatives.展开更多
One strain of Hypoxylon sp.CXM-3 and one strain of Sistotrema brinkmannii CXM-4 were inoculated onto sterilized cherry,poplar,birch,and basswood sheets in a certain shape and incubated at constant temperature and humi...One strain of Hypoxylon sp.CXM-3 and one strain of Sistotrema brinkmannii CXM-4 were inoculated onto sterilized cherry,poplar,birch,and basswood sheets in a certain shape and incubated at constant temperature and humidity for 4,8,12,and 16 weeks,respectively,to analyze whether the grain pattern formed by the zone lines was consistent with the predetermined pattern.The results showed that the zone lines of CXM-3 of Hypoxylon were free,delicate,and soft,with brown lines and black staining,mostly accompanied by black and brown dots,facets,and clusters,while the zone lines of CXM-4 of Sistotrema brinkmannii grew along the predetermined grain,with strong lines and a clean surface.After inoculation and incubation at a constant temperature of 25℃±2℃ and humidity of 60%,Sistotrema brinkmannii CXM-4,on basswood veneer at 4-8 weeks and cherry veneer at 4-16 weeks,were able to develop zone lines following a predetermined grain.Artificially induced spalted wood can only maintain a large shape,which cannot guarantee that the pattern of large-scale production of spalted wood is exactly the same and cannot be accurate to the minute details.The artificial induction can thus result in the formation of a predetermined grain pattern of the mottled wood,thus enhancing the product value and artistic value of solid wood furniture and crafts.展开更多
In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar...In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tomentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures, and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6~0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese white poplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation.展开更多
文摘Two activated carbons with controlled pore size were prepared from Eucalyptus wood by physical activation with carbon dioxide, giving the BET surface area and pore volume of738 m2/g and0.39 cm3/g, and921 m2/g and0.53 cm3/g for the carbon sample AC1 and AC2, respectively. These activated carbons were then used to remove the residual dye left after the silk-dyeing process. The dye solution used for adsorption study was a cationic aluminium dye complex of [Al(brazilein)2]+ derived from a mixture of alum and extract of the heartwood of Ceasalpinia sappan Linn., with initial dye concentration of 220 mg/l. Effects of adsorbent dosage, adsorption time and temperature in the range of 25℃40℃ on dye adsorption were investigated. It was found that the adsorption kinetics of this dye complex was best described by the pseudo-second order model. Adsorption isotherms of this dye complex were well fitted by Langmuir isotherm equation. The adsorption capacities for the uptake of this dye complex at 25℃, 30℃ and 40℃ were 718.7, 1240.4 and 1139.5 mg/g and 1010.5, 1586.1 and 1659.0 mg/g for carbon sample AC1 and AC2, respectively. From these results, it can be concluded that activated carbon containing a higher proportion of mesopores gave better dye removal efficiency, emphasizing the fact that a proper pore size distribution of carbon adsorbent is crucial for the effecttive removal of relatively large size of the dye molecules. Thermodynamic parameters, including free energy, enthalpy and entropy of adsorption, were also determined. The adsorption enthalpies for the removal of this dye complex of AC1 and AC2 were 105.3 and 55.6 kJ/mol, respectively, indicating that the adsorption is an endothermic process. It was found that the adsorption of this dye complex is spontaneous at the temperatures under investigation.
基金Chinese Academy of Forestry cooperated with Canada Innovation Investment.
文摘Three concentrations （2.8%, 2.0%, 1.2%） of Ammoniacal Copper Quaternary （ACQ） was selected to treat Lodgepole pine wood for evaluating ACQ treatment on mechanical properties of blue-stained wood. The bending modules of elasticity （MOE）, modules of rupture （MOR）, toughness and shearing strength parallel to grain on tangential surface, are tested according to the criteria GB1927-1943-91. Non-treated sample were also tested according to the same procedure. The results showed that the three groups specimen impregnated by different concentrations of ACQ solution met the AWPA standard 2003 of America （UC4A 6.4g/cm^3）. There were significant difference of toughness between treated wood and non-treated wood （p=0.01）, but there were no statistically significant differences among three concentrations in terms of toughness, and toughness of treated wood was approximately 20% lower than non-treated. MOR, MOE as well as sheafing strength parallel to grain were found to be not significantly different between treated wood and non-treated one, and there were no statistically significant difference among three concentrations of ACQ too. Toughness, MOR, MOE and sheafing strength parallel to grain increased with decrease of concentration of ACQ, but they were hardly affected by ACQ preservatives.
基金supported by the National Natural Science Foundation of China(No.32160347)the Key Laboratory of State Forestry Adminstration for Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China(Southwest Forestry University)(No.2019-KF14).
文摘One strain of Hypoxylon sp.CXM-3 and one strain of Sistotrema brinkmannii CXM-4 were inoculated onto sterilized cherry,poplar,birch,and basswood sheets in a certain shape and incubated at constant temperature and humidity for 4,8,12,and 16 weeks,respectively,to analyze whether the grain pattern formed by the zone lines was consistent with the predetermined pattern.The results showed that the zone lines of CXM-3 of Hypoxylon were free,delicate,and soft,with brown lines and black staining,mostly accompanied by black and brown dots,facets,and clusters,while the zone lines of CXM-4 of Sistotrema brinkmannii grew along the predetermined grain,with strong lines and a clean surface.After inoculation and incubation at a constant temperature of 25℃±2℃ and humidity of 60%,Sistotrema brinkmannii CXM-4,on basswood veneer at 4-8 weeks and cherry veneer at 4-16 weeks,were able to develop zone lines following a predetermined grain.Artificially induced spalted wood can only maintain a large shape,which cannot guarantee that the pattern of large-scale production of spalted wood is exactly the same and cannot be accurate to the minute details.The artificial induction can thus result in the formation of a predetermined grain pattern of the mottled wood,thus enhancing the product value and artistic value of solid wood furniture and crafts.
文摘In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tomentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures, and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6~0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese white poplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation.
