The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretical study. In order to aggr...The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretical study. In order to aggrandize the research of the calcination process, the kinetics and reaction mechanism of the calcinations were studied. The result suggests that there are two stages in the calcination process, and the alumina extraction rate increases swiftly in the initial stage, but slows down increasing in the later stage. The apparent activation energy of the initial and later stages equals to 13.31 and 35.65 kJ·mol-1, respectively. In the initial stage, ammonium sulfate reacts directly with mullite in the fly ash to form ammonium aluminum sulfate, while in the later stage, aluminum sulfate is formed by the reaction between ammonium aluminum sulfate and ammonium sulfate.展开更多
A novel method was developed for papain immobilization through a biomimetic silicification process induced by papain. By incubating papain in a silica precursor solution, the papain-silica composite formed rapidly and...A novel method was developed for papain immobilization through a biomimetic silicification process induced by papain. By incubating papain in a silica precursor solution, the papain-silica composite formed rapidly and oanain was encansulated. The encansulation efficiency and the recovery activity were 82.60% and 83.09%, re-spectively. Compared with enzymes and biomolecules immobilized in biosilica matrix in the presence of additaonal silica-precipitating species, this papaln encapsulation process, a biomimetic approach, realized high encapsulation efficiency by its autosilification activity under mild conditions （near-neutral pH and ambient temperature）. Fur-thermore, the encapsulated papain exhibits enhanced thermal, pH, recycling and storage stabilities. Kinetic analysis showed that the biomimetic silica matrix did not significantly hinder the mass transport of substrate or the release of product.展开更多
The adsorption behavior of molybdenum onto D314 was studied with the static adsorption method. The adsorption process was analyzed from thermodynamic and kinetic aspects. The experimental results show that the equilib...The adsorption behavior of molybdenum onto D314 was studied with the static adsorption method. The adsorption process was analyzed from thermodynamic and kinetic aspects. The experimental results show that the equilibrium adsorption data conform satisfactorily to the Langmuir equation. In the adsorption process of D314 for molybdenum, the enthalpy change ΔH is positive when temperature is in the range of 298-338 K, which indicates that the adsorption is an endothermic process, and the elevated temperature benefits to the adsorption. Kinetic analysis shows that the adsorption rate is controlled by intraparticle diffusion and chemical diffusion at the same time. The adsorption mechanism of molybdenum onto D314 was discussed based on IR spectra.展开更多
This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis （DMA） method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienc...This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis （DMA） method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienced ultravio- let aging, the low temperature performance of asphalt binder decreased significantly, with its complex modulus increased and phase angle decreased along with changing rheological properties as compared to the performance of original asphalt binder. The ultraviolet aging process would make asphalt binder more sensitive to brittle and fatigue failure. On the basis of the time-temperature superposition principle （TTSP）, the viscoelastic transition frequency （coT） is proposed to evaluate the effect of ultraviolet aging. It is found that with the increase in ultraviolet aging time, the cox moves to the lower frequency range gradually. Since the viscoelastic transition frequency is sensitive to the effect of aging, it can be used as an indicator of ultraviolet aging.展开更多
The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied us/ng non- isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up ...The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied us/ng non- isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870℃ ha both N2 and CO2 atmospheres, while further mass loss occurred ha CO2 atmosphere at higher temper- atures due to char-CO2 gasification. Replacement of N2 ha the combustion environment by CO2 delayed the com- bustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose （KAS） method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.展开更多
Coxsackie A virus is one of the major pathogens associated with hand, foot and mouth disease (HFMD). The etiological characteristics of Coxsackie A virus type 16 (CA16) are thought to correlate with the pathological p...Coxsackie A virus is one of the major pathogens associated with hand, foot and mouth disease (HFMD). The etiological characteristics of Coxsackie A virus type 16 (CA16) are thought to correlate with the pathological process of its infection. Two CA16 strains that were isolated from a severe HFMD patient presented with different plaque forms. This observation, along with biological analysis, indicated that the differences in the strains' biological characteristics, such as proliferation kinetics and immunogenicity, correlate with differences in their pathogenicity toward neonatal mice. Furthermore, these differences are thought to be associated with the sequence of the 5′ non-coding region of the viral genome and the VP1 structural region sequence. The results suggest that the biological and genetic characteristics of the CA16 viral strains are relevant to their pathogenicity.展开更多
基金Supported by the National Science and Technology Project of China(2012BAB01B00)
文摘The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretical study. In order to aggrandize the research of the calcination process, the kinetics and reaction mechanism of the calcinations were studied. The result suggests that there are two stages in the calcination process, and the alumina extraction rate increases swiftly in the initial stage, but slows down increasing in the later stage. The apparent activation energy of the initial and later stages equals to 13.31 and 35.65 kJ·mol-1, respectively. In the initial stage, ammonium sulfate reacts directly with mullite in the fly ash to form ammonium aluminum sulfate, while in the later stage, aluminum sulfate is formed by the reaction between ammonium aluminum sulfate and ammonium sulfate.
基金Supported by the National Natural Science Foundation of China （21006020, 21276060, 21276062）, the Natural Science Foundation of Hebei Province （B2010000035, B2011202095）, the Science and Technology Research Key Project of Higher School in Hebei Province （ZD2010118）, the Application Basic Research Plan Key Basic Research Project of Hebei Province （11965150D） and Open Funding Project of ~e National Key Laboratory ofBiochemi＇cal Engineering （China）.
文摘A novel method was developed for papain immobilization through a biomimetic silicification process induced by papain. By incubating papain in a silica precursor solution, the papain-silica composite formed rapidly and oanain was encansulated. The encansulation efficiency and the recovery activity were 82.60% and 83.09%, re-spectively. Compared with enzymes and biomolecules immobilized in biosilica matrix in the presence of additaonal silica-precipitating species, this papaln encapsulation process, a biomimetic approach, realized high encapsulation efficiency by its autosilification activity under mild conditions （near-neutral pH and ambient temperature）. Fur-thermore, the encapsulated papain exhibits enhanced thermal, pH, recycling and storage stabilities. Kinetic analysis showed that the biomimetic silica matrix did not significantly hinder the mass transport of substrate or the release of product.
基金Project(51104186)supported by the National Natural Science Foundation of China
文摘The adsorption behavior of molybdenum onto D314 was studied with the static adsorption method. The adsorption process was analyzed from thermodynamic and kinetic aspects. The experimental results show that the equilibrium adsorption data conform satisfactorily to the Langmuir equation. In the adsorption process of D314 for molybdenum, the enthalpy change ΔH is positive when temperature is in the range of 298-338 K, which indicates that the adsorption is an endothermic process, and the elevated temperature benefits to the adsorption. Kinetic analysis shows that the adsorption rate is controlled by intraparticle diffusion and chemical diffusion at the same time. The adsorption mechanism of molybdenum onto D314 was discussed based on IR spectra.
基金supported by the National Natural Science Foundation of China(NNSFC,Grant No.50808058)the New Century Excellent Talents in University,2007(NCETU)+1 种基金the National Science Foundation for Post-doctoral Scientists of China(NSFPSC,Grant No.20080430925)the Specialized Research Fund for the Doctoral Program of Higher Education of China(SRFDPHEC,Grant No.200902403)
文摘This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis （DMA） method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienced ultravio- let aging, the low temperature performance of asphalt binder decreased significantly, with its complex modulus increased and phase angle decreased along with changing rheological properties as compared to the performance of original asphalt binder. The ultraviolet aging process would make asphalt binder more sensitive to brittle and fatigue failure. On the basis of the time-temperature superposition principle （TTSP）, the viscoelastic transition frequency （coT） is proposed to evaluate the effect of ultraviolet aging. It is found that with the increase in ultraviolet aging time, the cox moves to the lower frequency range gradually. Since the viscoelastic transition frequency is sensitive to the effect of aging, it can be used as an indicator of ultraviolet aging.
基金financially supported by the National Science Centre(Poland)under grant No.N N512 457940the Ministry of Science and Higher Education(Poland)under the statutory funds(BS-1-103-3020/2016)
文摘The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied us/ng non- isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870℃ ha both N2 and CO2 atmospheres, while further mass loss occurred ha CO2 atmosphere at higher temper- atures due to char-CO2 gasification. Replacement of N2 ha the combustion environment by CO2 delayed the com- bustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose （KAS） method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.
基金supported by the National Basic Research Program of China (Grant No. 2011CB504903)the National Natural Science Foundation of China (Grant No. 81171573)+1 种基金the Important National Science & Technology Specific Projects (Grant No. 2009ZX10004-308)the General Program of Applied Basic Research Programs Commission, Foundation of Yunnan Province (Grant No. 2011FB116)
文摘Coxsackie A virus is one of the major pathogens associated with hand, foot and mouth disease (HFMD). The etiological characteristics of Coxsackie A virus type 16 (CA16) are thought to correlate with the pathological process of its infection. Two CA16 strains that were isolated from a severe HFMD patient presented with different plaque forms. This observation, along with biological analysis, indicated that the differences in the strains' biological characteristics, such as proliferation kinetics and immunogenicity, correlate with differences in their pathogenicity toward neonatal mice. Furthermore, these differences are thought to be associated with the sequence of the 5′ non-coding region of the viral genome and the VP1 structural region sequence. The results suggest that the biological and genetic characteristics of the CA16 viral strains are relevant to their pathogenicity.
