The metal-acid bifunctional catalysts have been used for bio-oil upgrading and pyrolytic lignin hydrocracking. In this work, the effects of the metal-acid bifunctional catalyst prop- erties, including acidity, pore si...The metal-acid bifunctional catalysts have been used for bio-oil upgrading and pyrolytic lignin hydrocracking. In this work, the effects of the metal-acid bifunctional catalyst prop- erties, including acidity, pore size and supported metal on hydrocracking of pyrolytic lignin in supercritical ethanol and hydrogen were investigated at 260 ℃. A series of catalysts were prepared and characterized by BET, XRD, and NHa-TPD techniques. The results showed that enhancing the acidity of the catalyst without metal can promote pyrolytic lignin poly- merization to form more solid and condensation to produce more water. The pore size of microporous catalyst was smaller than mesoporous catalyst. Together with strong acid- ity, it caused pyrolytic lignin further hydrocrack to numerous gas. Introducing Ru into acidic catalysts promoted pyrolytic lignin hydrocracking and inhibited the polymerization and condensation, which caused the yield of pyrolytic lignin liquefaction product to increase significantly. Therefore, bifunctional catalyst with high hydrocracking activity metal Ru supported on materials with acidic sites and mesopores was imperative to get satisfactory results for the conversion of pyrolytic lignin to liquid products under supercritical conditions and hydrogen atmosphere.展开更多
Algae of the order Laminariales represent main seaweed resource of Russia, Most important commercial species formerly belonged to Laminaria Lamoroux. However, taxonomic revision of this genus and resurrection of Sacch...Algae of the order Laminariales represent main seaweed resource of Russia, Most important commercial species formerly belonged to Laminaria Lamoroux. However, taxonomic revision of this genus and resurrection of Saccharina Stackhouse based on genetic studies resulted in transfer of most Laminaria species to Saccharina. At the Russian Pacific coasts Saccharina now includes 10 species, while only three species for sure represent Laminaria： L. longipes Bory de Saint-Vincent, L. solidungula J. Agardh, L. yezoensis Miyabe, their placement within Laminaria is supported by genetic data. All examined Far Eastern species of Saccharina are noticed to possess haptera in the form of rhizoids, whereas members of Laminaria have disk-like holdfasts （L. solidungula, L. yezoensis）, or creeping rhizomes （L. longipes）. Three unstudied genetically endemics from the Sea of Okhotsk： L. appressirhiza Petrov et Vozzhinskaya, L. inclinatorhiza Petrov et Vozzhinskaya, L. multiplicata Petrov et Suchovejeva, are still left within Laminaria, but they have rhizoids, so most probably belong to Saccharina. This morphological criterion is inapplicable to Atlantic Laminaria since the type species L. digitata （Hudson） Lamouroux has rhizoids.展开更多
The second part of this paper is devoted to the computational modelling of transient water migration in hardwood. During re-saturation, the moisture content, measured during the process by using X-ray attenuation (see...The second part of this paper is devoted to the computational modelling of transient water migration in hardwood. During re-saturation, the moisture content, measured during the process by using X-ray attenuation (see part 1 of this paper), increases quickly very close to the cavity, but requires a very long time for the remaining part of the sample to absorb the moisture in wetting. For this configuration and this material, the macroscopic approach fails. Consequently, a dual-porosity approach is proposed. The computational domain uses a 2-D axisymmetric configuration for which the axial coordinate represents the macroscopic longitudinal direction of the sample whereas the radial coordinate allows the slow migration from each active vessel towards the fibre zone to be considered. The latter is a microscopic space variable. The moisture content field evolution depicts clearly the dual scale mechanisms:a very fast longitudinal migration in the vessel followed by a slow migration from the vessel towards the fibre zone.The macroscopic moisture content field resulting from this dual scale mechanism is in quite good agreement with the experimental data.展开更多
An experimental device able to determine the moisture content of wood usingX-ray attenuation is used to study the imbibition of beech samples (Fagus silvatica). The apparatusincludes an X-ray generator, a protective t...An experimental device able to determine the moisture content of wood usingX-ray attenuation is used to study the imbibition of beech samples (Fagus silvatica). The apparatusincludes an X-ray generator, a protective tube, collimating plates and a 50 mm detector. Detectedparticles can be categorised by energy (accuracy of the order of 20%) or by position (accuracy 100μm). The independent choice of both the energy spectrum (through the voltage) and the counting rate(through the current intensity) makes the installation very flexible. However, a rigorous treatmentis necessary to deal with the attenuation of a polychromatic spectrum. The appropriate calculationsare presented and validated with homogeneous samples made of wood and water. In addition, someresults are presented with samples heterogeneous in density and moisture content. Finally, theexperimental device is used to study the evolution of moisture content during saturationexperiments, for which the moisture migration is mainly due to capillary forces. The geometricalconfiguration was so arranged that the transfer can be studied in two directions simultaneously.展开更多
An improved algorithm for symbolic computation of Hirota bilinear form of nonlinear equations by a logarithm transformation is presented. The improved algorithm is more efficient by using the property of Hirota-D oper...An improved algorithm for symbolic computation of Hirota bilinear form of nonlinear equations by a logarithm transformation is presented. The improved algorithm is more efficient by using the property of Hirota-D operator. The software package HBFTrans2 is written in Maple and its running efficiency is tested by a variety of soliton equations.展开更多
文摘The metal-acid bifunctional catalysts have been used for bio-oil upgrading and pyrolytic lignin hydrocracking. In this work, the effects of the metal-acid bifunctional catalyst prop- erties, including acidity, pore size and supported metal on hydrocracking of pyrolytic lignin in supercritical ethanol and hydrogen were investigated at 260 ℃. A series of catalysts were prepared and characterized by BET, XRD, and NHa-TPD techniques. The results showed that enhancing the acidity of the catalyst without metal can promote pyrolytic lignin poly- merization to form more solid and condensation to produce more water. The pore size of microporous catalyst was smaller than mesoporous catalyst. Together with strong acid- ity, it caused pyrolytic lignin further hydrocrack to numerous gas. Introducing Ru into acidic catalysts promoted pyrolytic lignin hydrocracking and inhibited the polymerization and condensation, which caused the yield of pyrolytic lignin liquefaction product to increase significantly. Therefore, bifunctional catalyst with high hydrocracking activity metal Ru supported on materials with acidic sites and mesopores was imperative to get satisfactory results for the conversion of pyrolytic lignin to liquid products under supercritical conditions and hydrogen atmosphere.
文摘Algae of the order Laminariales represent main seaweed resource of Russia, Most important commercial species formerly belonged to Laminaria Lamoroux. However, taxonomic revision of this genus and resurrection of Saccharina Stackhouse based on genetic studies resulted in transfer of most Laminaria species to Saccharina. At the Russian Pacific coasts Saccharina now includes 10 species, while only three species for sure represent Laminaria： L. longipes Bory de Saint-Vincent, L. solidungula J. Agardh, L. yezoensis Miyabe, their placement within Laminaria is supported by genetic data. All examined Far Eastern species of Saccharina are noticed to possess haptera in the form of rhizoids, whereas members of Laminaria have disk-like holdfasts （L. solidungula, L. yezoensis）, or creeping rhizomes （L. longipes）. Three unstudied genetically endemics from the Sea of Okhotsk： L. appressirhiza Petrov et Vozzhinskaya, L. inclinatorhiza Petrov et Vozzhinskaya, L. multiplicata Petrov et Suchovejeva, are still left within Laminaria, but they have rhizoids, so most probably belong to Saccharina. This morphological criterion is inapplicable to Atlantic Laminaria since the type species L. digitata （Hudson） Lamouroux has rhizoids.
文摘The second part of this paper is devoted to the computational modelling of transient water migration in hardwood. During re-saturation, the moisture content, measured during the process by using X-ray attenuation (see part 1 of this paper), increases quickly very close to the cavity, but requires a very long time for the remaining part of the sample to absorb the moisture in wetting. For this configuration and this material, the macroscopic approach fails. Consequently, a dual-porosity approach is proposed. The computational domain uses a 2-D axisymmetric configuration for which the axial coordinate represents the macroscopic longitudinal direction of the sample whereas the radial coordinate allows the slow migration from each active vessel towards the fibre zone to be considered. The latter is a microscopic space variable. The moisture content field evolution depicts clearly the dual scale mechanisms:a very fast longitudinal migration in the vessel followed by a slow migration from the vessel towards the fibre zone.The macroscopic moisture content field resulting from this dual scale mechanism is in quite good agreement with the experimental data.
文摘An experimental device able to determine the moisture content of wood usingX-ray attenuation is used to study the imbibition of beech samples (Fagus silvatica). The apparatusincludes an X-ray generator, a protective tube, collimating plates and a 50 mm detector. Detectedparticles can be categorised by energy (accuracy of the order of 20%) or by position (accuracy 100μm). The independent choice of both the energy spectrum (through the voltage) and the counting rate(through the current intensity) makes the installation very flexible. However, a rigorous treatmentis necessary to deal with the attenuation of a polychromatic spectrum. The appropriate calculationsare presented and validated with homogeneous samples made of wood and water. In addition, someresults are presented with samples heterogeneous in density and moisture content. Finally, theexperimental device is used to study the evolution of moisture content during saturationexperiments, for which the moisture migration is mainly due to capillary forces. The geometricalconfiguration was so arranged that the transfer can be studied in two directions simultaneously.
基金Supported by Scientific Research Fund of Zhejiang Provincial Education Department under Grant No.Y201017148the National Natural Science Foundations of China under Grant No.10735030+2 种基金the Natural Science Fund of Ningbo under Grant No.2009B21003the Scientific Research Fund of Ningbo University under Grant No.XKL09059the K.C.Wong Magana Fund in Ningbo University
文摘An improved algorithm for symbolic computation of Hirota bilinear form of nonlinear equations by a logarithm transformation is presented. The improved algorithm is more efficient by using the property of Hirota-D operator. The software package HBFTrans2 is written in Maple and its running efficiency is tested by a variety of soliton equations.
