For very high temperature annealing (1620℃) after ion implantation for 4H silicon carbide (4H SiC),the residual components of Al and O in the alundum furnace impact seriously on the surface of material,which yields ...For very high temperature annealing (1620℃) after ion implantation for 4H silicon carbide (4H SiC),the residual components of Al and O in the alundum furnace impact seriously on the surface of material,which yields the derivation of SiOC.This causes a significant degradation of the 4H SiC surface characteristics according to the results of surface composition analysis.As validity,Ni/SiC ohmic contact measurement illustrates a higher specific contact resistance than the normal value by a factor of 2～3.Consequently the MESFET fabricated with this kind of 4H SiC material results in a degraded I V output performance compared with that of normal 4H SiC MESFET.展开更多
The diffusion behaviours of vanadium implanted p- and n-type 4H-SiC are investigated by using the secondary ion mass spectrometry （SIMS）. Significant redistribution, especially out-diffusion of vanadium towards the ...The diffusion behaviours of vanadium implanted p- and n-type 4H-SiC are investigated by using the secondary ion mass spectrometry （SIMS）. Significant redistribution, especially out-diffusion of vanadium towards the sample surface is not observed after 1650 ℃annealing for both p- and n-type samples. Atomic force microscopy （AFM） is applied to the characterization of surface morphology, indicating the formation of continuous long furrows running in one direction across the wafer surface after 1650 ℃ annealing. The surface roughness results from the evaporation and re-deposition of Si species on the surface during annealing. The chemical compositions of sample surface axe investigated using x-ray photoelectron spectroscopy （XPS）. The results of C ls and Si 2p core-level spectra axe presented in detail to demonstrate the evaporation of Si from the wafer and the deposition of SiO2 on the sample surface during annealing.展开更多
The methods for protecting InP surface against degradation during annealing,including encapsulant and encapsulant-free techniques;rapid thermal annealing of InP implanted layers;implanted ion species and some profiles...The methods for protecting InP surface against degradation during annealing,including encapsulant and encapsulant-free techniques;rapid thermal annealing of InP implanted layers;implanted ion species and some profiles of typical dopants,etc.,they are all the key techniques concerning ion implantation into semi-insulating InP,and have been reviewed synthetically as well.展开更多
The effect of surface finish and annealing treatment on the oxidation behavior of Ti-48Al-8Cr-2Ag (molar fraction, %) alloy was investigated at 900 and 1 000 ℃, respectively in air. Thermal gravimetric analysis (TGA)...The effect of surface finish and annealing treatment on the oxidation behavior of Ti-48Al-8Cr-2Ag (molar fraction, %) alloy was investigated at 900 and 1 000 ℃, respectively in air. Thermal gravimetric analysis (TGA) was conducted for the characterization of oxidation kinetics. The microstructures of oxide scales were studied by scanning electron microscopy (SEM) and transmission election microscopy (TEM) techniques. Unfavorable effect of the annealing treatment on the oxidation behavior of the coating was also investigated. The results indicate that the oxidation behavior of the alloy is influenced by surface finish and annealing treatment. The oxidation rate of ground sample is lower than that of the polished alloy at 1 000 ℃ in air. The former forms a scale of merely Al2O3, and the latter forms a scale of the mixture of Al2O3 and TiO2. Annealing can improve the formation of TiO2.展开更多
Titanium and its alloys are widely used in the aerospace, marine, and biomedical industry due to their unique bulk properties such as high strength-to-weight ratio and melting temperature, good corrosion resistance, a...Titanium and its alloys are widely used in the aerospace, marine, and biomedical industry due to their unique bulk properties such as high strength-to-weight ratio and melting temperature, good corrosion resistance, and favorable biocom- patibility. However, in some applications, com- ponents made of titanium or titanium alloys exhibit poor wear resistance under stationary or dynamic loading as well as contact corrosion manifested by the relatively negative standard electrode potential （-1.63 V ） . In order to improve the surface properties of titanium and its alloys, several techniques such as PVD （ physical vapor deposition ） /CVD （chemical vapor deposition ） coatings,展开更多
Based on the smart home and facial expression recognition, this paper presents a cognitive emotional model for eldercare robot. By combining with Gabor filter, Local Binary Pattern algorithm(LBP) and k-Nearest Neighbo...Based on the smart home and facial expression recognition, this paper presents a cognitive emotional model for eldercare robot. By combining with Gabor filter, Local Binary Pattern algorithm(LBP) and k-Nearest Neighbor algorithm(KNN) are facial emotional features extracted and recognized. Meanwhile, facial emotional features put influence on robot's emotion state, which is described in AVS emotion space. Then the optimization of smart home environment on the cognitive emotional model is specially analyzed using simulated annealing algorithm(SA). Finally, transition probability from any emotional state to a state of basic emotions is obtained based on the cognitive reappraisal strategy and Euclidean distance. The simulation and experiment have tested and verified the effective in reducing negative emotional state.展开更多
Al-doped ZnO (ZAO) films were successfully deposited on the surface of common glasses by using low-temperature hydrothermal approach. In the reaction solution, the molar ratio of Al3+ to Zn2+ was 1∶100, the annealing...Al-doped ZnO (ZAO) films were successfully deposited on the surface of common glasses by using low-temperature hydrothermal approach. In the reaction solution, the molar ratio of Al3+ to Zn2+ was 1∶100, the annealing temperature and time were 200 ℃ and 2-6 h, respectively. The structure of the thin films was identified by X-ray diffraction (XRD), the surface morphology and thickness of the thin films were observed by scanning electron microscopy (SEM), and the electrical performance of the thin films was measured by four-point probes. It was shown that the films with an average particle size of 27.53 nm had a preferential orientation along (002), Al3+ had replaced the position of Zn2+ in the lattice without forming the Al2O3 phase and its thickness was 20-25 μm. With the increased annealing time, the intensity of diffraction peaks was decreased, the film exhibited irregular surface morphology gradually, and the resistivity of ZAO films was increased. The lowest resistivity obtained in this study was 3.45×10-5Ω·cm.展开更多
Fe BSi C metglas was annealed at an optimized condition（350 °C, 5 min） to achieve the mixed phases with pristine amorphous phase and crystallization phase.With such annealed metglas, a self-biased magnetoelect...Fe BSi C metglas was annealed at an optimized condition（350 °C, 5 min） to achieve the mixed phases with pristine amorphous phase and crystallization phase.With such annealed metglas, a self-biased magnetoelectric（ME） laminate of metglas/Pb（Zr, Ti）O3/metglas was fabricated. Without any external magnetic field, the composite exhibits the ME coefficient aE31 of 103 m V/（cm Oe） at1 k Hz and 15.5 V/（cm Oe） at electromechanical resonance frequency. The induced ME voltage shows a good linear relation to the applied AC magnetic field with amplitude as low as 10-7T at 1 k Hz. It is expected that such self-biased ME composites provide a practical application of economical and compact magnetic sensors.展开更多
文摘For very high temperature annealing (1620℃) after ion implantation for 4H silicon carbide (4H SiC),the residual components of Al and O in the alundum furnace impact seriously on the surface of material,which yields the derivation of SiOC.This causes a significant degradation of the 4H SiC surface characteristics according to the results of surface composition analysis.As validity,Ni/SiC ohmic contact measurement illustrates a higher specific contact resistance than the normal value by a factor of 2～3.Consequently the MESFET fabricated with this kind of 4H SiC material results in a degraded I V output performance compared with that of normal 4H SiC MESFET.
基金Project supported by the National Natural Science Foundation of China （Grant No 60376001）, the National Basic Research Program of China （Grant No 2002CB311904） and the National Defense Basic Research Program of China （Grant No 51327020202）. The authors express their gratitude to Ma Nongnong of Tianjin Electronic Materials Research Institute for performing SIMS measurements and to Li Ying of Xi＇an University of Technology for performing XPS measurements.
文摘The diffusion behaviours of vanadium implanted p- and n-type 4H-SiC are investigated by using the secondary ion mass spectrometry （SIMS）. Significant redistribution, especially out-diffusion of vanadium towards the sample surface is not observed after 1650 ℃annealing for both p- and n-type samples. Atomic force microscopy （AFM） is applied to the characterization of surface morphology, indicating the formation of continuous long furrows running in one direction across the wafer surface after 1650 ℃ annealing. The surface roughness results from the evaporation and re-deposition of Si species on the surface during annealing. The chemical compositions of sample surface axe investigated using x-ray photoelectron spectroscopy （XPS）. The results of C ls and Si 2p core-level spectra axe presented in detail to demonstrate the evaporation of Si from the wafer and the deposition of SiO2 on the sample surface during annealing.
文摘The methods for protecting InP surface against degradation during annealing,including encapsulant and encapsulant-free techniques;rapid thermal annealing of InP implanted layers;implanted ion species and some profiles of typical dopants,etc.,they are all the key techniques concerning ion implantation into semi-insulating InP,and have been reviewed synthetically as well.
基金Project(2007430028) supported by the Science and Technique Foundation of Henan Educational Committee, China
文摘The effect of surface finish and annealing treatment on the oxidation behavior of Ti-48Al-8Cr-2Ag (molar fraction, %) alloy was investigated at 900 and 1 000 ℃, respectively in air. Thermal gravimetric analysis (TGA) was conducted for the characterization of oxidation kinetics. The microstructures of oxide scales were studied by scanning electron microscopy (SEM) and transmission election microscopy (TEM) techniques. Unfavorable effect of the annealing treatment on the oxidation behavior of the coating was also investigated. The results indicate that the oxidation behavior of the alloy is influenced by surface finish and annealing treatment. The oxidation rate of ground sample is lower than that of the polished alloy at 1 000 ℃ in air. The former forms a scale of merely Al2O3, and the latter forms a scale of the mixture of Al2O3 and TiO2. Annealing can improve the formation of TiO2.
文摘Titanium and its alloys are widely used in the aerospace, marine, and biomedical industry due to their unique bulk properties such as high strength-to-weight ratio and melting temperature, good corrosion resistance, and favorable biocom- patibility. However, in some applications, com- ponents made of titanium or titanium alloys exhibit poor wear resistance under stationary or dynamic loading as well as contact corrosion manifested by the relatively negative standard electrode potential （-1.63 V ） . In order to improve the surface properties of titanium and its alloys, several techniques such as PVD （ physical vapor deposition ） /CVD （chemical vapor deposition ） coatings,
基金supported by National Natural Science Foundation of China (Normal Project No. 61170115), (Key Project No.61432004)National Key Technologies R&D Program of China (No.2014BAF08B04)the Foundation of Beijing Engineering and Technology Center for Convergence Networks and Ubiquitous Services
文摘Based on the smart home and facial expression recognition, this paper presents a cognitive emotional model for eldercare robot. By combining with Gabor filter, Local Binary Pattern algorithm(LBP) and k-Nearest Neighbor algorithm(KNN) are facial emotional features extracted and recognized. Meanwhile, facial emotional features put influence on robot's emotion state, which is described in AVS emotion space. Then the optimization of smart home environment on the cognitive emotional model is specially analyzed using simulated annealing algorithm(SA). Finally, transition probability from any emotional state to a state of basic emotions is obtained based on the cognitive reappraisal strategy and Euclidean distance. The simulation and experiment have tested and verified the effective in reducing negative emotional state.
文摘Al-doped ZnO (ZAO) films were successfully deposited on the surface of common glasses by using low-temperature hydrothermal approach. In the reaction solution, the molar ratio of Al3+ to Zn2+ was 1∶100, the annealing temperature and time were 200 ℃ and 2-6 h, respectively. The structure of the thin films was identified by X-ray diffraction (XRD), the surface morphology and thickness of the thin films were observed by scanning electron microscopy (SEM), and the electrical performance of the thin films was measured by four-point probes. It was shown that the films with an average particle size of 27.53 nm had a preferential orientation along (002), Al3+ had replaced the position of Zn2+ in the lattice without forming the Al2O3 phase and its thickness was 20-25 μm. With the increased annealing time, the intensity of diffraction peaks was decreased, the film exhibited irregular surface morphology gradually, and the resistivity of ZAO films was increased. The lowest resistivity obtained in this study was 3.45×10-5Ω·cm.
基金supported by the National Natural Science Foundation of China(51402164 and 51572142)
文摘Fe BSi C metglas was annealed at an optimized condition（350 °C, 5 min） to achieve the mixed phases with pristine amorphous phase and crystallization phase.With such annealed metglas, a self-biased magnetoelectric（ME） laminate of metglas/Pb（Zr, Ti）O3/metglas was fabricated. Without any external magnetic field, the composite exhibits the ME coefficient aE31 of 103 m V/（cm Oe） at1 k Hz and 15.5 V/（cm Oe） at electromechanical resonance frequency. The induced ME voltage shows a good linear relation to the applied AC magnetic field with amplitude as low as 10-7T at 1 k Hz. It is expected that such self-biased ME composites provide a practical application of economical and compact magnetic sensors.
