3Gd2O3-3Yb2O3-4Y2O3 （mole fraction, %） co-doped ZrO2 （GY-YSZ） thermal barrier coatings （TBCs） were produced by electron beam physical vapor deposition （EB-PVD）. The oxidation behavior of GY-YSZ at 1 050 ℃ was...3Gd2O3-3Yb2O3-4Y2O3 （mole fraction, %） co-doped ZrO2 （GY-YSZ） thermal barrier coatings （TBCs） were produced by electron beam physical vapor deposition （EB-PVD）. The oxidation behavior of GY-YSZ at 1 050 ℃ was investigated using impedance spectroscopy （IS） combined with scanning electron microscopy （SEM）, Raman spectroscopy and X-ray diffractometry （XRD）. Various electrical responses observed in the impedance spectra corresponding to GY-YSZ grains and grain boundaries were explained using circuit modeling. The change in the conduction mechanism of GY-YSZ was found to be related to the O^2- vacancy and lattice distortion due to the stabilizer diffusion during the oxidation. The results also suggested that the specific oxidation information about the GY-YSZ grains and grain boundaries should be acquired at a moderate measurement temperature, which was related to the resistance value in the impedance spectra. The resistance values of the GY-YSZ grains and grain boundaries should be measured at 200 ℃ and 300 ℃, respectively.展开更多
Plasma electrolytic oxidation (PEO) ceramic coatings were fabricated in a silicate-based electrolyte with the addition of potassium fluorozirconate (K2ZrF6) on 6063 aluminum alloy, and the effects of current density o...Plasma electrolytic oxidation (PEO) ceramic coatings were fabricated in a silicate-based electrolyte with the addition of potassium fluorozirconate (K2ZrF6) on 6063 aluminum alloy, and the effects of current density on microstructure and properties of the PEO coatings were studied. It was found that pore density of the coatings decreased with increasing the current density. The tribological and hardness tests suggested that the ceramic coating produced under the current density of 15 A/dm2showed the best mechanical property, which matched well with the phase analysis. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves proved that the coating obtained under 15 A/dm2 displayed the best anti-corrosion property, which was directly connected with morphologies of coatings.展开更多
Hot carrier induced (HCI) degradation of surface channel n MOSFETs with different oxide thicknesses is investigated under maximum substrate current condition.Results show that the key parameters m and n of H...Hot carrier induced (HCI) degradation of surface channel n MOSFETs with different oxide thicknesses is investigated under maximum substrate current condition.Results show that the key parameters m and n of Hu's lifetime prediction model have a close relationship with oxide thickness.Furthermore,a linear relationship is found between m and n .Based on this result,the lifetime prediction model can be expended to the device with thinner oxides.展开更多
Aim To obtain a kind of electrorheological (ER) flind with high comprehensive properties in order to satisfy the needs of engineering application. Methods A new type of dispersed phase── composite ultrafine particle...Aim To obtain a kind of electrorheological (ER) flind with high comprehensive properties in order to satisfy the needs of engineering application. Methods A new type of dispersed phase── composite ultrafine particles (UFP) was obtained by the method of microemulsion, which was used to mix with silicon oil. aam electroinduced stress and apparent viscosity of the ER fluids with three different volume fractions were tested under the conditions of different temperatures, electric fields and shear rates. Results A series of systematic tests show that the new type of ER fluids with volume fraction of 30% possesses obvious ER effect. Conclusion The double layers polarization plays an important role in ER effect.展开更多
基金Projects (50771009, 50731001 and 51071013) supported by the National Natural Science Foundations of China Project (2010CB631200) supported by the National Basic Research Program of China
文摘3Gd2O3-3Yb2O3-4Y2O3 （mole fraction, %） co-doped ZrO2 （GY-YSZ） thermal barrier coatings （TBCs） were produced by electron beam physical vapor deposition （EB-PVD）. The oxidation behavior of GY-YSZ at 1 050 ℃ was investigated using impedance spectroscopy （IS） combined with scanning electron microscopy （SEM）, Raman spectroscopy and X-ray diffractometry （XRD）. Various electrical responses observed in the impedance spectra corresponding to GY-YSZ grains and grain boundaries were explained using circuit modeling. The change in the conduction mechanism of GY-YSZ was found to be related to the O^2- vacancy and lattice distortion due to the stabilizer diffusion during the oxidation. The results also suggested that the specific oxidation information about the GY-YSZ grains and grain boundaries should be acquired at a moderate measurement temperature, which was related to the resistance value in the impedance spectra. The resistance values of the GY-YSZ grains and grain boundaries should be measured at 200 ℃ and 300 ℃, respectively.
基金Project(51371039)supported by the National Natural Science Foundation of China
文摘Plasma electrolytic oxidation (PEO) ceramic coatings were fabricated in a silicate-based electrolyte with the addition of potassium fluorozirconate (K2ZrF6) on 6063 aluminum alloy, and the effects of current density on microstructure and properties of the PEO coatings were studied. It was found that pore density of the coatings decreased with increasing the current density. The tribological and hardness tests suggested that the ceramic coating produced under the current density of 15 A/dm2showed the best mechanical property, which matched well with the phase analysis. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves proved that the coating obtained under 15 A/dm2 displayed the best anti-corrosion property, which was directly connected with morphologies of coatings.
文摘Hot carrier induced (HCI) degradation of surface channel n MOSFETs with different oxide thicknesses is investigated under maximum substrate current condition.Results show that the key parameters m and n of Hu's lifetime prediction model have a close relationship with oxide thickness.Furthermore,a linear relationship is found between m and n .Based on this result,the lifetime prediction model can be expended to the device with thinner oxides.
文摘Aim To obtain a kind of electrorheological (ER) flind with high comprehensive properties in order to satisfy the needs of engineering application. Methods A new type of dispersed phase── composite ultrafine particles (UFP) was obtained by the method of microemulsion, which was used to mix with silicon oil. aam electroinduced stress and apparent viscosity of the ER fluids with three different volume fractions were tested under the conditions of different temperatures, electric fields and shear rates. Results A series of systematic tests show that the new type of ER fluids with volume fraction of 30% possesses obvious ER effect. Conclusion The double layers polarization plays an important role in ER effect.
