Aim A new solid SMEDDS (self-microemulsifying drug delivery system) capsule has been developed to increase the solubility and dissolution rate. Methods The solubilities of carvedilol in various bases were investigated...Aim A new solid SMEDDS (self-microemulsifying drug delivery system) capsule has been developed to increase the solubility and dissolution rate. Methods The solubilities of carvedilol in various bases were investigated. Ternary phase diagrams were used to evaluate the self-emulsification and self-microemulsfication domains. The particle size distribution and ζ-potential were determined. The mean diameter of the three formulae decreased with an increase of Lutrol F68. Results The in vitro dissolution rate of ...展开更多
The vacuum medium-frequency induction melting technology was employed to prepare the Cu-15%Cr-0.24%Zr alloy. The scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, transmission electron micr...The vacuum medium-frequency induction melting technology was employed to prepare the Cu-15%Cr-0.24%Zr alloy. The scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM） were used to analyze the phase composition, morphology and structure of the alloy. The results reveal that the as-cast structure of the alloy consists of Cu matrix, Cr dendrite, eutectic Cr and Zr-rich phase. A large number of Cr-precipitated phases occur in the Cu matrix, and Cu5Zr particles can be found in the grain boundary of Cu matrix. The HRTEM images prove that there is a semi-coherent relationship between Cu5Zr and Cu matrix.展开更多
Morphology and crystal structure of β precipitate phase in Mg-7Gd-5Y-1Nd-0.5Zr (mass fraction, %) alloy were characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy. Com...Morphology and crystal structure of β precipitate phase in Mg-7Gd-5Y-1Nd-0.5Zr (mass fraction, %) alloy were characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy. Compositions were determined for β phase using thin foil energy dispersive spectroscopy. Precipitation at 400 ℃ involves formation of platelet and block-shaped β phase. The orientation relationship is and between β precipitate phase and α-Mg matrix with habit planes parallel to , and a composition of Mg5(Y0.4Gd0.4Nd0.2) is suggested for the β phase in Mg-7Gd-5Y-1Nd-0.5Zr alloy.展开更多
The precipitation kinetics of 2519 A aluminum alloy after different cold rolling reductions before aging was investigated by hardness test and differential scanning calorimetry（DSC）. The activation energy was calcul...The precipitation kinetics of 2519 A aluminum alloy after different cold rolling reductions before aging was investigated by hardness test and differential scanning calorimetry（DSC）. The activation energy was calculated according to DSC curves using single heating rate method. The microstructures of as-rolled and peak-aged alloys were observed by transmission electron microscopy（TEM）. The result shows that the age hardenability reduces and the activation energy rises with increasing the reduction from 7% to 40%. Nonuniform dislocations are found in as-rolled alloy and inhomogeneous distribution of θ′ phase is revealed in peak-aged alloy when the reduction is 15%. The inhomogeneous distribution of θ′ phase may be related to the age hardenability reducing and activation energy rising.展开更多
[Objective] The aim was to research the relationships among different e- valuation farmland units and conduct division-of farmland use in order to provide scientific references for protection and rational use of farml...[Objective] The aim was to research the relationships among different e- valuation farmland units and conduct division-of farmland use in order to provide scientific references for protection and rational use of farmland at county level. [Method] Using Pingdu City as a case, the research selected land use indices such as farmland use structure, output, geographical location, eta/., and then performed a cluster analysis for farmland use division. [Result] Farmlands in Pingdu can be classified into 4 groups. In groups 1 and 2, it is necessary to strengthen farmland protection, especially for highly-quality farmlands, to guarantee the quantity and quality of local crops. In groups 1 and 3, it is necessary to improve concentration degree and use rate of construction lands and control farmland pollution possibly caused by constructions. In group 4, priority should be given to maintaining diversity of land use patterns, and avoiding aimless farming expansion. [Conclusion] During urbanization process in eastern coastal agricultural regions, it is of importance to prevent fertile farmlands being occupied by construction lands to enhance use rate of construction lands. Furthermore, agricultural non-point pollution should be detected constantly in intensively used farmlands, especially in vegetable fields. Additionally, land use diversity should be well protected by avoiding farmland expansion and im- proving farmland environment.展开更多
The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2＋ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different condition...The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2＋ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different conditions of initial total-iron amount as well as mole ratio of Fe（III） to Fe（II） in the solutions containing synthetic extracellular polymeric substances （EPS）.When the solution potential is lower than 650 mV （vs SHE）,the inhibition of jarosites to bioleaching chalcopyrite is not vital as EPS produced by bacteria can retard the contamination through flocculating jarosites even if concentration of Fe（III） ions is up to 20 g/L but increases with increasing the concentration of Fe（III） ions;jarosites formed by bio-oxidized Fe3＋ ions are more easy to adhere to outside surface of EPS space on chalcopyrite;the EPS layer with jarosites acts as a weak diffusion barrier to further rapidly create a high redox potential of more than 650 mV by bio-oxidizing Fe^2＋ ions inside and outside EPS space into Fe^3＋ ions,resulting in a rapid deterioration of ion diffusion performance of the EPS layer to inhibit bioleaching chalcopyrite severely and irreversibly.展开更多
A study was conducted for metal extraction from copper smelting dust using the oxidation leaching and control of potential technology.The effects of H2O2 dosage,H2O2 feeding speed,initial HCl concentration,leaching te...A study was conducted for metal extraction from copper smelting dust using the oxidation leaching and control of potential technology.The effects of H2O2 dosage,H2O2 feeding speed,initial HCl concentration,leaching temperature,liquid-to-solid ratio and leaching time on metals leaching efficiencies were investigated.The following optimized leaching conditions were obtained:H2O2 dosage of 0.8 mL/g(redox potential of 429 mV),H2O2 feeding speed of 1.0 mL/min,initial H2SO4 concentration of 1.0 mol/L,initial HCl concentration of 1.0 mol/L,leaching temperature of 80°C,initial liquid-to-solid ratio of 5:1 mL/g and leaching time of 1.5 h.Under the optimized conditions,copper and arsenic can be effectively leached from copper smelting dust,leaving residue as a suitable lead resource.The average leaching efficiencies of copper,arsenic and iron are 95.27%,96.82%and 46.65%,respectively.展开更多
文摘Aim A new solid SMEDDS (self-microemulsifying drug delivery system) capsule has been developed to increase the solubility and dissolution rate. Methods The solubilities of carvedilol in various bases were investigated. Ternary phase diagrams were used to evaluate the self-emulsification and self-microemulsfication domains. The particle size distribution and ζ-potential were determined. The mean diameter of the three formulae decreased with an increase of Lutrol F68. Results The in vitro dissolution rate of ...
基金Project(11YZ112)supported by Innovation Project of Shanghai Educational Committee in ChinaProject(J50503)supported by Shanghai Municipal Education Commission in China+1 种基金Project(10JC1411800)supported by Key Basic Research Project of Shanghai Committee of Science and Technology in ChinaProject(JWCXSL1101)supported by Shanghai Graduate Innovation Fund in China
文摘The vacuum medium-frequency induction melting technology was employed to prepare the Cu-15%Cr-0.24%Zr alloy. The scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM） were used to analyze the phase composition, morphology and structure of the alloy. The results reveal that the as-cast structure of the alloy consists of Cu matrix, Cr dendrite, eutectic Cr and Zr-rich phase. A large number of Cr-precipitated phases occur in the Cu matrix, and Cu5Zr particles can be found in the grain boundary of Cu matrix. The HRTEM images prove that there is a semi-coherent relationship between Cu5Zr and Cu matrix.
基金Project (2011DAE22B01) supported by the Key Technologies Program of China during the 12th Fire-Year Plan Period
文摘Morphology and crystal structure of β precipitate phase in Mg-7Gd-5Y-1Nd-0.5Zr (mass fraction, %) alloy were characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy. Compositions were determined for β phase using thin foil energy dispersive spectroscopy. Precipitation at 400 ℃ involves formation of platelet and block-shaped β phase. The orientation relationship is and between β precipitate phase and α-Mg matrix with habit planes parallel to , and a composition of Mg5(Y0.4Gd0.4Nd0.2) is suggested for the β phase in Mg-7Gd-5Y-1Nd-0.5Zr alloy.
基金Project(2012CB619500)supported by the National Basic Research Program of China
文摘The precipitation kinetics of 2519 A aluminum alloy after different cold rolling reductions before aging was investigated by hardness test and differential scanning calorimetry（DSC）. The activation energy was calculated according to DSC curves using single heating rate method. The microstructures of as-rolled and peak-aged alloys were observed by transmission electron microscopy（TEM）. The result shows that the age hardenability reduces and the activation energy rises with increasing the reduction from 7% to 40%. Nonuniform dislocations are found in as-rolled alloy and inhomogeneous distribution of θ′ phase is revealed in peak-aged alloy when the reduction is 15%. The inhomogeneous distribution of θ′ phase may be related to the age hardenability reducing and activation energy rising.
基金Supported by National Natural Science Foundation of China[41371531(2014-2017)]~~
文摘[Objective] The aim was to research the relationships among different e- valuation farmland units and conduct division-of farmland use in order to provide scientific references for protection and rational use of farmland at county level. [Method] Using Pingdu City as a case, the research selected land use indices such as farmland use structure, output, geographical location, eta/., and then performed a cluster analysis for farmland use division. [Result] Farmlands in Pingdu can be classified into 4 groups. In groups 1 and 2, it is necessary to strengthen farmland protection, especially for highly-quality farmlands, to guarantee the quantity and quality of local crops. In groups 1 and 3, it is necessary to improve concentration degree and use rate of construction lands and control farmland pollution possibly caused by constructions. In group 4, priority should be given to maintaining diversity of land use patterns, and avoiding aimless farming expansion. [Conclusion] During urbanization process in eastern coastal agricultural regions, it is of importance to prevent fertile farmlands being occupied by construction lands to enhance use rate of construction lands. Furthermore, agricultural non-point pollution should be detected constantly in intensively used farmlands, especially in vegetable fields. Additionally, land use diversity should be well protected by avoiding farmland expansion and im- proving farmland environment.
基金Project(2010CB630904) supported by the National Basic Research Program of ChinaProject(50621063) supported by the Chinese Science Foundation for Distinguished Group
文摘The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2＋ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different conditions of initial total-iron amount as well as mole ratio of Fe（III） to Fe（II） in the solutions containing synthetic extracellular polymeric substances （EPS）.When the solution potential is lower than 650 mV （vs SHE）,the inhibition of jarosites to bioleaching chalcopyrite is not vital as EPS produced by bacteria can retard the contamination through flocculating jarosites even if concentration of Fe（III） ions is up to 20 g/L but increases with increasing the concentration of Fe（III） ions;jarosites formed by bio-oxidized Fe3＋ ions are more easy to adhere to outside surface of EPS space on chalcopyrite;the EPS layer with jarosites acts as a weak diffusion barrier to further rapidly create a high redox potential of more than 650 mV by bio-oxidizing Fe^2＋ ions inside and outside EPS space into Fe^3＋ ions,resulting in a rapid deterioration of ion diffusion performance of the EPS layer to inhibit bioleaching chalcopyrite severely and irreversibly.
基金Project(2016M602427)supported by the Postdoctoral Science Foundation of ChinaProject supported by the Fundamental Research Funds for the Central Universities of Central South University,China
文摘A study was conducted for metal extraction from copper smelting dust using the oxidation leaching and control of potential technology.The effects of H2O2 dosage,H2O2 feeding speed,initial HCl concentration,leaching temperature,liquid-to-solid ratio and leaching time on metals leaching efficiencies were investigated.The following optimized leaching conditions were obtained:H2O2 dosage of 0.8 mL/g(redox potential of 429 mV),H2O2 feeding speed of 1.0 mL/min,initial H2SO4 concentration of 1.0 mol/L,initial HCl concentration of 1.0 mol/L,leaching temperature of 80°C,initial liquid-to-solid ratio of 5:1 mL/g and leaching time of 1.5 h.Under the optimized conditions,copper and arsenic can be effectively leached from copper smelting dust,leaving residue as a suitable lead resource.The average leaching efficiencies of copper,arsenic and iron are 95.27%,96.82%and 46.65%,respectively.
