Close-space sublimation(CSS)has been demonstrated as an alternative vacuum deposition technique for fabricating organic light-emitting diodes(OLEDs).CSS utilizes a planar donor plate pre-coated with organic thin films...Close-space sublimation(CSS)has been demonstrated as an alternative vacuum deposition technique for fabricating organic light-emitting diodes(OLEDs).CSS utilizes a planar donor plate pre-coated with organic thin films as an area source to rapidly transfer the donor film to a device substrate at temperatures below 200℃.CSS is also conformal and capable of depositing on odd-shaped substrates using flexible donor media.The evaporation behaviors of organic donor films under CSS were fully characterized using model OLED materials and CSS-deposited films exhibited comparable device performances in an OLED stack to films deposited by conventional point sources.The low temperature and conformal nature of CSS,along with its high material utilization and short process time,make it a promising method for fabricating flexible OLED displays.展开更多
The influence of outside inertial shock combined with RF signal voltages on the properties of a shunt capacitive MEMS switch encapsulated in a low vacuum environment is analyzed considering the damping of the air arou...The influence of outside inertial shock combined with RF signal voltages on the properties of a shunt capacitive MEMS switch encapsulated in a low vacuum environment is analyzed considering the damping of the air around the MEMS switch membrane. An analytical expression that approximately computes the displacement induced by outside shock is obtained. According to the expression, the minimum required mechanical stiffness constant of an MEMS switch beam in some maximum tolerated insertion loss condition and some external inertial shock environment or the insertion loss induced by external inertial shock can also be obtained. The influence is also illustrated with an RF MEMS capacitive switch example,which shows that outside environment factors have to be taken into account when designing RF MEMS capacitive switches working in low vacuum. While encapsulating RF MEMS switches in low vacuum diminishes the air damping and improves the switch speed and operation voltage,the performances of a switch is incident to being influenced by outside environment. This study is very useful for the optimized design of RF MEMS capacitive switches working in low vacuum.展开更多
Based on a two-dimensional axisymmetric magneto-hydrodynamic (MHD) model, low current vacuum arc (LCVA) characteristics are studied. The influence of cathode process under different axial magnetic fields and diffe...Based on a two-dimensional axisymmetric magneto-hydrodynamic (MHD) model, low current vacuum arc (LCVA) characteristics are studied. The influence of cathode process under different axial magnetic fields and different anode radii on LCVA characteristics is also simulated. The results show that the influence of both cathode process and anode radii on LCVA is significant. The sign of anode sheath potentials can change from negative to positive with the decrease of anode radii. The simulation results are in part verified by experimental results. Especially, as the effect of ion kinetic energy is considered, ion temperature is improved significantly; which is in agreement with experimental results.展开更多
In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show ...In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show that the ion temperature, electron temperature, ion number density, axial current density and plasma pressure all decrease with the increase of the cathode IJAs. It is also shown that LCVA can cause a current constriction for lower cathode IND, and the anode sheath potential is more nonuniform, which is mainly related to the nonuniform distribution of the axial current density at the anode side.展开更多
Municipal sludge is a sedimentation waste produced during the wastewater process in sewage treatment plants.Among recent studies,pilot and field tests showed that chemical conditioning combined with vacuum preloading ...Municipal sludge is a sedimentation waste produced during the wastewater process in sewage treatment plants.Among recent studies,pilot and field tests showed that chemical conditioning combined with vacuum preloading can effectively treat municipal sludge.To further understand the drainage and consolidation characteristics of the conditioning sludge during vacuum preloading,a large deformation nonlinear numerical simulation model based on the equal strain condition was developed to simulate and analyze the pilot and field tests,whereas the simulation results were not satisfactory.The results of the numerical analysis of the pilot test showed that the predicted consolidation degree was greater than that measured by the field tests,which is attributed to the relatively low permeability layer formed during the preloading process of the prefabricated vertical drain.To better reflect the consolidation process of the conditioned sludge,a simplified analysis method considering the low permeability layer around the prefabricated vertical drain was proposed.The initial permeability coefficient of the low permeability layer is determined via numerical simulations using finite difference method.The predicted settlement curve was in good agreement with the measured results,which indicated that the numerical simulation based on the equal strain condition considering the relatively low permeability layer can better analyze the consolidation process of ferric chloride-conditioning sludge with vacuum preloading.展开更多
A multi-effect distillation technology for seawater desalination driven by tidal energy and low grade energy is presented.In the system,tidal energy is utilized to supply power instead of coventional electric pumps du...A multi-effect distillation technology for seawater desalination driven by tidal energy and low grade energy is presented.In the system,tidal energy is utilized to supply power instead of coventional electric pumps during the operation,resulting in the decrease of dependence on steady electric power supply and a reduction in the running costs.According to the technological principle,a testing unit is designed and built.The effects of the feed seawater temperature and the heat source temperature on the unit performance are tested and analyzed.The experimental results show that the fresh water output is 27 kg/h when the heating water temperature is 65 ℃ and the absolute pressure is 25 kPa.The experimental and theoretical analysis results indicate that the appropriate heating water temperature is a key factor in ensuring the steady operation of the system.展开更多
基金financially supported by the General Research Fund(16309918)from the Research Grant Council,Hong Kongfunding from the Institute for Advanced Study of the Hong Kong University of Science and Technology。
文摘Close-space sublimation(CSS)has been demonstrated as an alternative vacuum deposition technique for fabricating organic light-emitting diodes(OLEDs).CSS utilizes a planar donor plate pre-coated with organic thin films as an area source to rapidly transfer the donor film to a device substrate at temperatures below 200℃.CSS is also conformal and capable of depositing on odd-shaped substrates using flexible donor media.The evaporation behaviors of organic donor films under CSS were fully characterized using model OLED materials and CSS-deposited films exhibited comparable device performances in an OLED stack to films deposited by conventional point sources.The low temperature and conformal nature of CSS,along with its high material utilization and short process time,make it a promising method for fabricating flexible OLED displays.
文摘The influence of outside inertial shock combined with RF signal voltages on the properties of a shunt capacitive MEMS switch encapsulated in a low vacuum environment is analyzed considering the damping of the air around the MEMS switch membrane. An analytical expression that approximately computes the displacement induced by outside shock is obtained. According to the expression, the minimum required mechanical stiffness constant of an MEMS switch beam in some maximum tolerated insertion loss condition and some external inertial shock environment or the insertion loss induced by external inertial shock can also be obtained. The influence is also illustrated with an RF MEMS capacitive switch example,which shows that outside environment factors have to be taken into account when designing RF MEMS capacitive switches working in low vacuum. While encapsulating RF MEMS switches in low vacuum diminishes the air damping and improves the switch speed and operation voltage,the performances of a switch is incident to being influenced by outside environment. This study is very useful for the optimized design of RF MEMS capacitive switches working in low vacuum.
基金National Natural Science Foundation of China (No.50537050)the Innovation Foundation of State Key Laboratory of Electrical Insulation and Power Equipment
文摘Based on a two-dimensional axisymmetric magneto-hydrodynamic (MHD) model, low current vacuum arc (LCVA) characteristics are studied. The influence of cathode process under different axial magnetic fields and different anode radii on LCVA characteristics is also simulated. The results show that the influence of both cathode process and anode radii on LCVA is significant. The sign of anode sheath potentials can change from negative to positive with the decrease of anode radii. The simulation results are in part verified by experimental results. Especially, as the effect of ion kinetic energy is considered, ion temperature is improved significantly; which is in agreement with experimental results.
基金National Natural Science Foundation of China(No.50537050)
文摘In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show that the ion temperature, electron temperature, ion number density, axial current density and plasma pressure all decrease with the increase of the cathode IJAs. It is also shown that LCVA can cause a current constriction for lower cathode IND, and the anode sheath potential is more nonuniform, which is mainly related to the nonuniform distribution of the axial current density at the anode side.
基金acknowledge the financial support from The National Natural Science Foundation No.Gk321002Foundation of Nanjing Hydraulic Research Institute No.Y320012.
文摘Municipal sludge is a sedimentation waste produced during the wastewater process in sewage treatment plants.Among recent studies,pilot and field tests showed that chemical conditioning combined with vacuum preloading can effectively treat municipal sludge.To further understand the drainage and consolidation characteristics of the conditioning sludge during vacuum preloading,a large deformation nonlinear numerical simulation model based on the equal strain condition was developed to simulate and analyze the pilot and field tests,whereas the simulation results were not satisfactory.The results of the numerical analysis of the pilot test showed that the predicted consolidation degree was greater than that measured by the field tests,which is attributed to the relatively low permeability layer formed during the preloading process of the prefabricated vertical drain.To better reflect the consolidation process of the conditioned sludge,a simplified analysis method considering the low permeability layer around the prefabricated vertical drain was proposed.The initial permeability coefficient of the low permeability layer is determined via numerical simulations using finite difference method.The predicted settlement curve was in good agreement with the measured results,which indicated that the numerical simulation based on the equal strain condition considering the relatively low permeability layer can better analyze the consolidation process of ferric chloride-conditioning sludge with vacuum preloading.
基金The Key Basic Program of Science and Technology Commission of Shanghai Municipality(No.08110511700)the ShanghaiLeading Academic Discipline Program(No.S30503)
文摘A multi-effect distillation technology for seawater desalination driven by tidal energy and low grade energy is presented.In the system,tidal energy is utilized to supply power instead of coventional electric pumps during the operation,resulting in the decrease of dependence on steady electric power supply and a reduction in the running costs.According to the technological principle,a testing unit is designed and built.The effects of the feed seawater temperature and the heat source temperature on the unit performance are tested and analyzed.The experimental results show that the fresh water output is 27 kg/h when the heating water temperature is 65 ℃ and the absolute pressure is 25 kPa.The experimental and theoretical analysis results indicate that the appropriate heating water temperature is a key factor in ensuring the steady operation of the system.