A series of self-reducing bifunctional Ni-W/SBA-15 catalysts were synthesized using biomass-based carbon source as the reducing agent without conventional further reduction step. The self-reducing catalysts were perfo...A series of self-reducing bifunctional Ni-W/SBA-15 catalysts were synthesized using biomass-based carbon source as the reducing agent without conventional further reduction step. The self-reducing catalysts were performed on the hydrogenolysis of cellulose to low carbon polyols. The effects of calcination temperature and metallic loading contents for cellulose hydrogenolysis reaction were investigated detailedly.The optimal calcination temperature was found to be 673 K by TG analysis. The active metal nanoparticles with a better dispersion were observed using SEM and element mapping technology. The yield of low carbon polyols using the catalyst with the receipt of 10%Ni-15%W/SBA-15-673 K can reach as high as68.14%, of which the ethylene glycol(EG) accounts for 61.04%.展开更多
The wild hawthorn species,Crataegus songorica K.Koch.,is an important wild germplasm resource in Xinjiang,China that has been endangered in recent years.The genetic diversity of C.songorica K.Koch.germplasm in five po...The wild hawthorn species,Crataegus songorica K.Koch.,is an important wild germplasm resource in Xinjiang,China that has been endangered in recent years.The genetic diversity of C.songorica K.Koch.germplasm in five populations from Daxigou,Xinjiang,China were evaluated based on phenotypic traits and ISSR molecular markers to provide basic information on resource protection,rational utilization and genetic improvement.The F-value for the phenotypic differentiation coefficient of the 33 traits measured ranged from 0.266 to 15.128,and mean value was 13.85%.The variation among populations was found to be lower than that within population.A total of 303 loci were detected within the five populations by 12 primers.Within 298 polymorphic loci,the polymorphism was 98.35%,showing a high genetic diversity in C.songorica K.Koch.The gene diversity within population,total population genetic diversity,genetic differentiation coefficient and gene flow were 0.2779,0.3235,0.1408,and 3.0511,respectively.Our results showed that C.songorica K.Koch.from Xinjiang has a high level of genetic diversity at both the phenotypic and molecular levels.Significant genetic differentiation existed within population and the differentiation trend showed a regional association.And in this study,in situ and ex situ conservation approaches were raised for wild hawthorn protection utilization.展开更多
The negative pressure conical fluidized bed is widely used in the pharmaceutical industry.In this study,experiments based on the negative pressure conical fluidized bed are carried out by changing the material mass an...The negative pressure conical fluidized bed is widely used in the pharmaceutical industry.In this study,experiments based on the negative pressure conical fluidized bed are carried out by changing the material mass and particle size.The pressure fluctuation signals are analyzed by the time and the frequency domain methods.A method for absolutely characterizing the degree of the energy concentration at the main frequency is proposed,where the calculation is to divide the original power spectrum by the average signal power.A phenomenon where the gas velocity curve temporarily stops growing is observed when the material mass is light,and the particle size is small.The standard deviation and kurtosis both rapidly change at the minimum fluidization velocity and thus can be used to determine the flow regime,and the variation rule of the kurtosis is independent of both the material mass and particle size.In the initial fluidization stage,the dominant pressure signal comes from the material movement;with the increase in the gas velocity,the power of a 2.5 Hz signal continues to increase.A method of dividing the main frequency by the average cycle frequency can conveniently determine the fluidized state,and a novel concept called stable fluidized zone proposed in this paper can be obtained.Controlling the gas velocity within the stable fluidized zone ensures that the fluidized bed consistently remains in a stable fluidized state.展开更多
Silicon nanowires of high purity and regular morphology are of prime importance to ensure high specific capacities of lithium-ion batteries and reproducible electrode assembly process.Using nickel formate as a metal c...Silicon nanowires of high purity and regular morphology are of prime importance to ensure high specific capacities of lithium-ion batteries and reproducible electrode assembly process.Using nickel formate as a metal catalyst precursor,straight silicon nanowires(65–150 nm in diameter)were directly prepared by electrolysis from the Ni/SiO2 porous pellets with 0.8 wt%nickel content in molten CaCl2 at 900℃.Benefiting from their straight appearance and high purity,the silicon nanowires therefore offered an initial coulombic efficiency of 90.53% and specific capacity of 3377 m Ah/g.In addition,the silicon nanowire/carbon composite exhibited excellent cycle performance,retaining 90.38%of the initial capacity after 100 cycles.Whilst further study on the charge storage performance is still ongoing,these preliminary results demonstrate that nickel formate is an efficient and effective metal catalyst precursor for catalytic preparation of high purity straight silicon nanowires via the molten salt electrolysis,which is suitable for large-scale production.展开更多
基金supported by scientific research project of Zhejiang Provincial Education Department(Grant No.Y20112088,China)Science and technology project of Zhejiang Province(Grant No.2011R09028-10,China)
文摘A series of self-reducing bifunctional Ni-W/SBA-15 catalysts were synthesized using biomass-based carbon source as the reducing agent without conventional further reduction step. The self-reducing catalysts were performed on the hydrogenolysis of cellulose to low carbon polyols. The effects of calcination temperature and metallic loading contents for cellulose hydrogenolysis reaction were investigated detailedly.The optimal calcination temperature was found to be 673 K by TG analysis. The active metal nanoparticles with a better dispersion were observed using SEM and element mapping technology. The yield of low carbon polyols using the catalyst with the receipt of 10%Ni-15%W/SBA-15-673 K can reach as high as68.14%, of which the ethylene glycol(EG) accounts for 61.04%.
基金supported by the Special Research Projects of National Forestry Industry of Public Benefit,China(201304701-1)the Key Discipline of Horticultural of Xinjiang Uygur Autonomous Region of China(2016-10758-3)the Key Laboratory of Characteristics of Fruit Trees Center of Xinjiang Agricultural University,China
文摘The wild hawthorn species,Crataegus songorica K.Koch.,is an important wild germplasm resource in Xinjiang,China that has been endangered in recent years.The genetic diversity of C.songorica K.Koch.germplasm in five populations from Daxigou,Xinjiang,China were evaluated based on phenotypic traits and ISSR molecular markers to provide basic information on resource protection,rational utilization and genetic improvement.The F-value for the phenotypic differentiation coefficient of the 33 traits measured ranged from 0.266 to 15.128,and mean value was 13.85%.The variation among populations was found to be lower than that within population.A total of 303 loci were detected within the five populations by 12 primers.Within 298 polymorphic loci,the polymorphism was 98.35%,showing a high genetic diversity in C.songorica K.Koch.The gene diversity within population,total population genetic diversity,genetic differentiation coefficient and gene flow were 0.2779,0.3235,0.1408,and 3.0511,respectively.Our results showed that C.songorica K.Koch.from Xinjiang has a high level of genetic diversity at both the phenotypic and molecular levels.Significant genetic differentiation existed within population and the differentiation trend showed a regional association.And in this study,in situ and ex situ conservation approaches were raised for wild hawthorn protection utilization.
基金the National Standardization Project of TCM(ZYBZH-C-TJ-55)and National Science and Technology Major Project(2018ZX09201011-002).
文摘The negative pressure conical fluidized bed is widely used in the pharmaceutical industry.In this study,experiments based on the negative pressure conical fluidized bed are carried out by changing the material mass and particle size.The pressure fluctuation signals are analyzed by the time and the frequency domain methods.A method for absolutely characterizing the degree of the energy concentration at the main frequency is proposed,where the calculation is to divide the original power spectrum by the average signal power.A phenomenon where the gas velocity curve temporarily stops growing is observed when the material mass is light,and the particle size is small.The standard deviation and kurtosis both rapidly change at the minimum fluidization velocity and thus can be used to determine the flow regime,and the variation rule of the kurtosis is independent of both the material mass and particle size.In the initial fluidization stage,the dominant pressure signal comes from the material movement;with the increase in the gas velocity,the power of a 2.5 Hz signal continues to increase.A method of dividing the main frequency by the average cycle frequency can conveniently determine the fluidized state,and a novel concept called stable fluidized zone proposed in this paper can be obtained.Controlling the gas velocity within the stable fluidized zone ensures that the fluidized bed consistently remains in a stable fluidized state.
基金financially supported by the National Key R&D Program of China (No. 2016YFB0100400)the National Natural Science Foundation of China (No. 51604032)
文摘Silicon nanowires of high purity and regular morphology are of prime importance to ensure high specific capacities of lithium-ion batteries and reproducible electrode assembly process.Using nickel formate as a metal catalyst precursor,straight silicon nanowires(65–150 nm in diameter)were directly prepared by electrolysis from the Ni/SiO2 porous pellets with 0.8 wt%nickel content in molten CaCl2 at 900℃.Benefiting from their straight appearance and high purity,the silicon nanowires therefore offered an initial coulombic efficiency of 90.53% and specific capacity of 3377 m Ah/g.In addition,the silicon nanowire/carbon composite exhibited excellent cycle performance,retaining 90.38%of the initial capacity after 100 cycles.Whilst further study on the charge storage performance is still ongoing,these preliminary results demonstrate that nickel formate is an efficient and effective metal catalyst precursor for catalytic preparation of high purity straight silicon nanowires via the molten salt electrolysis,which is suitable for large-scale production.
