Chemical components are the main factors affecting the mechanical properties of wood fibers. Lignin is one of the main components of wood cell walls and has a critical effect on the mechanical properties of paper pulp...Chemical components are the main factors affecting the mechanical properties of wood fibers. Lignin is one of the main components of wood cell walls and has a critical effect on the mechanical properties of paper pulp and wood fiber based composites. In this study, we carried out tensile tests on single mature latewood tracheids of Chi- nese fir （Cunninghamia lanciolata （Lamb.） Hook.）, using three different delignified treatment methods to obtain different amounts of lignin. We applied single fiber tests to study the effect of the amount of lignin on mechanical tensile proper- ties of single wood fibers at the cellular level. The results show that in their dry state, the modulus of elasticity of single fi- bers decreased with the reduction in the amount of Iignin; even their absolute values were not high. The amount of lignin affects the tensile strength and elongation of single fibers considerably. Tensile strength and elongation of single fibers increase with a reduction in the amount of lignin.展开更多
The construction,performance characteristics and application of a new bismuth（Ⅲ） PVC membrane electrode based on 5-（3,4,5-trimethoxyphenyl）-4-amino-1,2,4-triazole-3-thiol are reported in this paper.The designed s...The construction,performance characteristics and application of a new bismuth（Ⅲ） PVC membrane electrode based on 5-（3,4,5-trimethoxyphenyl）-4-amino-1,2,4-triazole-3-thiol are reported in this paper.The designed sensor exhibited a Nernstian response for Bi^3＋ ion ranging from 5.0×10^-7 mol/L to1.0×10^-2 mol/L with a slope of 19.8 mV/decade.The operational pH range of the sensor is 3.0-6.0.The electrode shows a response time of 6 s and can be used for at least five weeks without any considerable divergence in potentials.It exhibits very good selectivity relative to a wide variety of alkali,alkaline earth,transition and heavy metal ions.The proposed electrode could be used as an indicator electrode in potentiometric titration of Bi^3＋ ions with EDTA and in the determination of Bi^3＋ content in stomach medicine.展开更多
基金supported by the Key Program of the National Natural Science Foundation of China (Grant No. 30730076)
文摘Chemical components are the main factors affecting the mechanical properties of wood fibers. Lignin is one of the main components of wood cell walls and has a critical effect on the mechanical properties of paper pulp and wood fiber based composites. In this study, we carried out tensile tests on single mature latewood tracheids of Chi- nese fir （Cunninghamia lanciolata （Lamb.） Hook.）, using three different delignified treatment methods to obtain different amounts of lignin. We applied single fiber tests to study the effect of the amount of lignin on mechanical tensile proper- ties of single wood fibers at the cellular level. The results show that in their dry state, the modulus of elasticity of single fi- bers decreased with the reduction in the amount of Iignin; even their absolute values were not high. The amount of lignin affects the tensile strength and elongation of single fibers considerably. Tensile strength and elongation of single fibers increase with a reduction in the amount of lignin.
基金supported by the Science Foundation of Henan Province(No.142102310336)
文摘The construction,performance characteristics and application of a new bismuth（Ⅲ） PVC membrane electrode based on 5-（3,4,5-trimethoxyphenyl）-4-amino-1,2,4-triazole-3-thiol are reported in this paper.The designed sensor exhibited a Nernstian response for Bi^3＋ ion ranging from 5.0×10^-7 mol/L to1.0×10^-2 mol/L with a slope of 19.8 mV/decade.The operational pH range of the sensor is 3.0-6.0.The electrode shows a response time of 6 s and can be used for at least five weeks without any considerable divergence in potentials.It exhibits very good selectivity relative to a wide variety of alkali,alkaline earth,transition and heavy metal ions.The proposed electrode could be used as an indicator electrode in potentiometric titration of Bi^3＋ ions with EDTA and in the determination of Bi^3＋ content in stomach medicine.
