High temperature plastic deformation behavior of non-orientated electrical steel was investigated by Gleeble 1500 thermo-mechanical simulator at strain rate of 0.01-10 s^-1 and high temperature of 500-1 200 ℃. The st...High temperature plastic deformation behavior of non-orientated electrical steel was investigated by Gleeble 1500 thermo-mechanical simulator at strain rate of 0.01-10 s^-1 and high temperature of 500-1 200 ℃. The stress level factor （a）, stress exponent （n）, structural factor （A） and activation energy （Q） of high temperature plastic deformation process of non-orientated electrical steel in different temperature ranges were calculated by the Arrhenius model. The results show that, with dynamic elevation of deformation temperature, phase transformation from α-Fe to γ-Fe takes place simultaneously during plastic deformation, dynamic recovery and dynamic recrystallization process, leading to an irregular change of the steady flow stress. For high temperature plastic deformation between 500 and 800 ℃, the calculated values of a, n, A, and Q are 0.039 0 MPa 1, 7.93, 1.9× 10^18 s^-1, and 334.8 kJ/mol, respectively, and for high temperature plastic deformation between 1 050 and 1 200 ℃, the calculated values of a, n, A, and Q are 0.125 8 MPa1, 5.29, 1.0 × 10^28 s^-1, and 769.9 kJ/mol, respectively.展开更多
In this study, Bismuth doped Titanium dioxide thin films were deposited on glass substrates by a pulse laser deposition using laser. The effect of annealing temperature on the structural and electrical properties was ...In this study, Bismuth doped Titanium dioxide thin films were deposited on glass substrates by a pulse laser deposition using laser. The effect of annealing temperature on the structural and electrical properties was investigated. X-ray diffraction pattern for pure and doped titanium dioxide films with different doping different ratio with Bi show that these films have amorphous structure oanvert to polycrystalline structure with annealing and doping and have a good identically with standard peaks for Anatase and Rutile phases. The orientation was at specific direction for Rutile. The crystalline of films increases by the increase of doping ratio. The crystalline increased with annealing temperature. Annealed films at different annealing temperatures have been studied. The results show that these films have two activation energies and by increasing the doping ratio, the activation energies and the conductivity increase. Both the annealing and composition effects on Hall constant, density of electron carders and Hall mobility are studied. Hall Effect measurements show that all films have n- type charge conductivity and the concentration increases while the mobility decreases with doping and annealing.展开更多
Formulation of poorly water-soluble crystalline drugs in their amorphous counterpart is a common approach to enhance their biodisponibility. In this study, the amorphous forms of ketoprofen and flurbiprofen were obtai...Formulation of poorly water-soluble crystalline drugs in their amorphous counterpart is a common approach to enhance their biodisponibility. In this study, the amorphous forms of ketoprofen and flurbiprofen were obtained by supercooling of the melt in a DSC （differential scanning calorimetry） apparatus and then investigated, especially under the stability point of view. The average rate of molecular motions at any given temperature is probably the most important parameter to know for amorphous pharmaceutical materials, and it was used to explain and predict the stability of ketoprofen and flurbiprofen. A quantitative estimate of the product＇s behaviour upon storage is obtained with additional data, such as the heat capacity of crystalline and amorphous samples and the distribution of molecular relaxation times. Amorphous flurbiprofen demonstrated greater physical stability at any aging temperature tested, when compared to ketoprofen and a different dependence from aging temperature. Both amorphous drugs could he classified as ＂fragile＂ ones.展开更多
In this paper, the electron temperature gradient （ETG） instability and corresponding turbulent transport in toroidal plasmas with negative magnetic shear is studied using the integral eigenvalue equations. The full ...In this paper, the electron temperature gradient （ETG） instability and corresponding turbulent transport in toroidal plasmas with negative magnetic shear is studied using the integral eigenvalue equations. The full electron kinetics is considered and the behaviours of the modes and the transport in the parameter regimes close to the instability threshold are emphasized. The fitting formulas of the critical gradient, for negative magnetic shear, are given.展开更多
基金Project(2005038560) supported by the Postdoctoral Foundation of ChinaProject(05GK1002-2) supported by Key Program of Hunan Province
文摘High temperature plastic deformation behavior of non-orientated electrical steel was investigated by Gleeble 1500 thermo-mechanical simulator at strain rate of 0.01-10 s^-1 and high temperature of 500-1 200 ℃. The stress level factor （a）, stress exponent （n）, structural factor （A） and activation energy （Q） of high temperature plastic deformation process of non-orientated electrical steel in different temperature ranges were calculated by the Arrhenius model. The results show that, with dynamic elevation of deformation temperature, phase transformation from α-Fe to γ-Fe takes place simultaneously during plastic deformation, dynamic recovery and dynamic recrystallization process, leading to an irregular change of the steady flow stress. For high temperature plastic deformation between 500 and 800 ℃, the calculated values of a, n, A, and Q are 0.039 0 MPa 1, 7.93, 1.9× 10^18 s^-1, and 334.8 kJ/mol, respectively, and for high temperature plastic deformation between 1 050 and 1 200 ℃, the calculated values of a, n, A, and Q are 0.125 8 MPa1, 5.29, 1.0 × 10^28 s^-1, and 769.9 kJ/mol, respectively.
文摘In this study, Bismuth doped Titanium dioxide thin films were deposited on glass substrates by a pulse laser deposition using laser. The effect of annealing temperature on the structural and electrical properties was investigated. X-ray diffraction pattern for pure and doped titanium dioxide films with different doping different ratio with Bi show that these films have amorphous structure oanvert to polycrystalline structure with annealing and doping and have a good identically with standard peaks for Anatase and Rutile phases. The orientation was at specific direction for Rutile. The crystalline of films increases by the increase of doping ratio. The crystalline increased with annealing temperature. Annealed films at different annealing temperatures have been studied. The results show that these films have two activation energies and by increasing the doping ratio, the activation energies and the conductivity increase. Both the annealing and composition effects on Hall constant, density of electron carders and Hall mobility are studied. Hall Effect measurements show that all films have n- type charge conductivity and the concentration increases while the mobility decreases with doping and annealing.
文摘Formulation of poorly water-soluble crystalline drugs in their amorphous counterpart is a common approach to enhance their biodisponibility. In this study, the amorphous forms of ketoprofen and flurbiprofen were obtained by supercooling of the melt in a DSC （differential scanning calorimetry） apparatus and then investigated, especially under the stability point of view. The average rate of molecular motions at any given temperature is probably the most important parameter to know for amorphous pharmaceutical materials, and it was used to explain and predict the stability of ketoprofen and flurbiprofen. A quantitative estimate of the product＇s behaviour upon storage is obtained with additional data, such as the heat capacity of crystalline and amorphous samples and the distribution of molecular relaxation times. Amorphous flurbiprofen demonstrated greater physical stability at any aging temperature tested, when compared to ketoprofen and a different dependence from aging temperature. Both amorphous drugs could he classified as ＂fragile＂ ones.
基金Supported by the National Natural Science Foundation of China（10135020）
文摘In this paper, the electron temperature gradient （ETG） instability and corresponding turbulent transport in toroidal plasmas with negative magnetic shear is studied using the integral eigenvalue equations. The full electron kinetics is considered and the behaviours of the modes and the transport in the parameter regimes close to the instability threshold are emphasized. The fitting formulas of the critical gradient, for negative magnetic shear, are given.
