Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structu...Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structure. Annealed at 500 ℃, nanometer TiO 2 with a specific surface area of 101.39 m 2 ·g -1 and a grain size about 10 nm were obtained(pH=5); and with a specific surface area of 95.48 m 2 ·g -1 and a grain size about 30 nm were obtained(pH=10). The research indicated that crystal phase transformation of rutile at 750 ℃made great promotion in grain size growth.展开更多
Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structu...Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structure. Annealed at 500 ℃, nanometer TiO 2 with a specific surface area of 101.39 m 2 ·g -1 and a grain size about 10 nm were obtained(pH=5); and with a specific surface area of 95.48 m 2 ·g -1 and a grain size about 30 nm were obtained(pH=10). The research indicated that crystal phase transformation of rutile at 750 ℃made great promotion in grain size growth.展开更多
Al Ferron timed complex colorimetric method (AFM) and 27 Al NMR spectroscopy method(ANM) were discussed. For the former, the different colorimetric reagent preparation methods' results indicate that the...Al Ferron timed complex colorimetric method (AFM) and 27 Al NMR spectroscopy method(ANM) were discussed. For the former, the different colorimetric reagent preparation methods' results indicate that there are some differences beteween them, and the combined method can be used as a simplified procedure. For the latter, the small tube method is more accurate. Eventually, the Al 13 (ANM) was compared to the Al b (AFM).展开更多
Low melting point metals（Ga, In, Sn） as alloy elements were used to prepare Al-In-Sn and Al-Ga-In-Sn alloys through mechanical ball milling method. The effects of mass ratio of In to Sn and Ga content on the hydroly...Low melting point metals（Ga, In, Sn） as alloy elements were used to prepare Al-In-Sn and Al-Ga-In-Sn alloys through mechanical ball milling method. The effects of mass ratio of In to Sn and Ga content on the hydrolysis properties of aluminum alloys were investigated. X-ray diffraction（XRD） and scanning electron microscopy（SEM） with energy disperse spectroscopy（EDS） were used to analyze the compositions and morphologies of the obtained Al alloys. The results show that the phase compositions of Al-In-Sn ternary alloys are Al and two intermetallic compounds, In3 Sn and In Sn4. All Al-In-Sn ternary alloys exhibit poor hydrolysis activity at room temperature. Al-In-Sn alloy with the mass ratio of In to Sn equaling 1：4 has the highest hydrogen yield. After Ga is introduced to the ternary alloys, the hydrolysis activity of aluminum alloys at room temperature is greatly improved. It is speculated that the addition of Ga element promotes the formation of defects inside the Al alloys and Ga-In3Sn-In Sn4 eutectic alloys on the alloys surface. Al atoms can be dissolved in this eutectic phase and become the active spots during the hydrolysis process. The small size and uniform distribution of this eutectic phase may be responsible for the enhancement of hydrolysis activity.展开更多
The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also stu...The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also studied. The experimental results showed that the nano-TiO_2 caleinated at 600-700℃ contained the obvious anatase phase and exerted exeeUent antibacterial activity. The feature of antibacterial activity of nano- TiO_2 was non-strains specificity and exerted best antibacterial activity at concentration of 0.8 g/L.展开更多
SDS-PAGE was applied to determine trypsin activity and inhibition. After the hydrolysis by trypsin to substrate bovine serum albulnin (BSA) under different temperatures and pH, the hydrolysis degree of BSA was conduct...SDS-PAGE was applied to determine trypsin activity and inhibition. After the hydrolysis by trypsin to substrate bovine serum albulnin (BSA) under different temperatures and pH, the hydrolysis degree of BSA was conducted using SDS-PAGE. From the quantitative analysis to the electrophoresis bands of BSA and its hydrolysis products in SDS-PAGE pattern, the change of trypsin activity was determined, and then the optimum temperature at 40°C and the optimum pH at pH 8.5 - 8.7 for trypsin activity were obtained. All the target bonds in BSA molecule could be hydrolyzed at the same time by trypsin. The inhibition was due to the binding of inhibitor to trypsin, which made it impossible for trypsin to touch the substrate protein. SDS-PAGE was demonstrated to be also an effect method for assaying the characteristics of trypsin activity and its inhibition.展开更多
In this work, the enzymatic hydrolysis reaction of sucrose through invertase under unsteady-state conditions has been investigated. The aim is to evaluate the inhibition phenomena influence on the reaction rate and, t...In this work, the enzymatic hydrolysis reaction of sucrose through invertase under unsteady-state conditions has been investigated. The aim is to evaluate the inhibition phenomena influence on the reaction rate and, then, on the concentration and temperature profiles by simulating the process in a tubular reactor, varying the enzyme concentration and the reactant mixture velocity. The transport phenomena considered during the enzymatic hydrolysis process have been described by means of unsteady-state momentum, mass and energy balance equations, taking into account molecular and convective transport and generation terms. Interpretation and discussion of the results obtained by FEM resolution of PDEs involved allow to understand the relevance of the operating parameters.展开更多
文摘Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structure. Annealed at 500 ℃, nanometer TiO 2 with a specific surface area of 101.39 m 2 ·g -1 and a grain size about 10 nm were obtained(pH=5); and with a specific surface area of 95.48 m 2 ·g -1 and a grain size about 30 nm were obtained(pH=10). The research indicated that crystal phase transformation of rutile at 750 ℃made great promotion in grain size growth.
文摘Nanometer TiO 2 powders were obtained from TiOSO 4 and studied by XRD, TEM and BET. The result indicated that pH and heat treatment temperature have great effects on their grain size and crystal phase structure. Annealed at 500 ℃, nanometer TiO 2 with a specific surface area of 101.39 m 2 ·g -1 and a grain size about 10 nm were obtained(pH=5); and with a specific surface area of 95.48 m 2 ·g -1 and a grain size about 30 nm were obtained(pH=10). The research indicated that crystal phase transformation of rutile at 750 ℃made great promotion in grain size growth.
文摘Al Ferron timed complex colorimetric method (AFM) and 27 Al NMR spectroscopy method(ANM) were discussed. For the former, the different colorimetric reagent preparation methods' results indicate that there are some differences beteween them, and the combined method can be used as a simplified procedure. For the latter, the small tube method is more accurate. Eventually, the Al 13 (ANM) was compared to the Al b (AFM).
基金Project(2010CB635107) supported by the Major State Basic Research Development Program of ChinaProjects(51202064,51472081) supported by the National Natural Science Foundation of China+2 种基金Project(2013CFA085) supported by the Natural Science Foundation of Hubei Province,ChinaProject(2013070104010016) supported by Wuhan Youth Chenguang Program of Science and Technology,ChinaProject([2013]2-22) supported by the Open Fund of Key Laboratory of Green Materials for Light Industry of Hubei Province,China
文摘Low melting point metals（Ga, In, Sn） as alloy elements were used to prepare Al-In-Sn and Al-Ga-In-Sn alloys through mechanical ball milling method. The effects of mass ratio of In to Sn and Ga content on the hydrolysis properties of aluminum alloys were investigated. X-ray diffraction（XRD） and scanning electron microscopy（SEM） with energy disperse spectroscopy（EDS） were used to analyze the compositions and morphologies of the obtained Al alloys. The results show that the phase compositions of Al-In-Sn ternary alloys are Al and two intermetallic compounds, In3 Sn and In Sn4. All Al-In-Sn ternary alloys exhibit poor hydrolysis activity at room temperature. Al-In-Sn alloy with the mass ratio of In to Sn equaling 1：4 has the highest hydrogen yield. After Ga is introduced to the ternary alloys, the hydrolysis activity of aluminum alloys at room temperature is greatly improved. It is speculated that the addition of Ga element promotes the formation of defects inside the Al alloys and Ga-In3Sn-In Sn4 eutectic alloys on the alloys surface. Al atoms can be dissolved in this eutectic phase and become the active spots during the hydrolysis process. The small size and uniform distribution of this eutectic phase may be responsible for the enhancement of hydrolysis activity.
基金Funded by the Research Fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No.AE201037the Foundation for Talent Recruitment of Yancheng Institute of Technology(No.XKR2011007)
文摘The nano-TiO_2 particles were prepared by liquid hydrolysis method and characterized using XRD. Its antibacterial activity against two representative bacterial, Escherichia eoli and Staphylococcus aureus, was also studied. The experimental results showed that the nano-TiO_2 caleinated at 600-700℃ contained the obvious anatase phase and exerted exeeUent antibacterial activity. The feature of antibacterial activity of nano- TiO_2 was non-strains specificity and exerted best antibacterial activity at concentration of 0.8 g/L.
文摘SDS-PAGE was applied to determine trypsin activity and inhibition. After the hydrolysis by trypsin to substrate bovine serum albulnin (BSA) under different temperatures and pH, the hydrolysis degree of BSA was conducted using SDS-PAGE. From the quantitative analysis to the electrophoresis bands of BSA and its hydrolysis products in SDS-PAGE pattern, the change of trypsin activity was determined, and then the optimum temperature at 40°C and the optimum pH at pH 8.5 - 8.7 for trypsin activity were obtained. All the target bonds in BSA molecule could be hydrolyzed at the same time by trypsin. The inhibition was due to the binding of inhibitor to trypsin, which made it impossible for trypsin to touch the substrate protein. SDS-PAGE was demonstrated to be also an effect method for assaying the characteristics of trypsin activity and its inhibition.
文摘In this work, the enzymatic hydrolysis reaction of sucrose through invertase under unsteady-state conditions has been investigated. The aim is to evaluate the inhibition phenomena influence on the reaction rate and, then, on the concentration and temperature profiles by simulating the process in a tubular reactor, varying the enzyme concentration and the reactant mixture velocity. The transport phenomena considered during the enzymatic hydrolysis process have been described by means of unsteady-state momentum, mass and energy balance equations, taking into account molecular and convective transport and generation terms. Interpretation and discussion of the results obtained by FEM resolution of PDEs involved allow to understand the relevance of the operating parameters.
