Air corona discharge is one of the critical problems associated with high-voltage equipment. Investigating the corona mechanism plays a key role in enhancing the electrical insulation performance. An improved self-con...Air corona discharge is one of the critical problems associated with high-voltage equipment. Investigating the corona mechanism plays a key role in enhancing the electrical insulation performance. An improved self-consistent multi-component two-dimensional plasma hybrid model is presented for the simulation of a direct current atmospheric pressure corona discharge in air. The model is based on plasma hydrodynamic and chemical models, and includes 12 species and 26 reactions. In addition, the photoionization effect is introduced into the model. The simulation on a bar-plate electrode configuration with an inter-electrode gap of 5.0 mm is carried out. The discharge voltage- current characteristics and the current density distribution predicted by the hybrid model agree with the experimental measurements. In addition, the dynamics of volume charged species generation, discharge current waveform, current density distribution at an electrode, charge density, electron temperature, and electric field variations are investigated in detail based on the model. The results indicate that the model can contribute valuable insights into the physics of an air plasma discharge.展开更多
The molecular materials with structures of luminescent core and peripheral carrier groups （e.g. carbazoles）, have exhibited high-performance in organic light-emitting diodes （OLEDs）. Present work is to understand ...The molecular materials with structures of luminescent core and peripheral carrier groups （e.g. carbazoles）, have exhibited high-performance in organic light-emitting diodes （OLEDs）. Present work is to understand the basic process of electronic and energy exchange between the peripheral functional groups and the central core through quantum chemical analysis. As an example, 4,7-bis（9,9-bis（6-（9H-carbazol-9-yl）hexyl）-9H-fluoren-2-yl）benzo[c]- [1,2,5]thiadiazole （TCBzC） is investigated in regards to optoelectronic properties using density functional theory （DFT）. The results suggest that the forbidden transition from peripheral carbazole to the central chromophore core makes for separated electrical and optical properties, and high performance electroluminescence （EL） is mainly at- tributed to the energy-transfer from carbazoles to the fluorene derivative core.展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2011CB209401)the National Natural Science Foundation of China (Grant No. 51007096)the Scientific Research Foundation of State Key Lab of Power Transmission Equipment and System Security, China (Grant No. 2007DA10512709102)
文摘Air corona discharge is one of the critical problems associated with high-voltage equipment. Investigating the corona mechanism plays a key role in enhancing the electrical insulation performance. An improved self-consistent multi-component two-dimensional plasma hybrid model is presented for the simulation of a direct current atmospheric pressure corona discharge in air. The model is based on plasma hydrodynamic and chemical models, and includes 12 species and 26 reactions. In addition, the photoionization effect is introduced into the model. The simulation on a bar-plate electrode configuration with an inter-electrode gap of 5.0 mm is carried out. The discharge voltage- current characteristics and the current density distribution predicted by the hybrid model agree with the experimental measurements. In addition, the dynamics of volume charged species generation, discharge current waveform, current density distribution at an electrode, charge density, electron temperature, and electric field variations are investigated in detail based on the model. The results indicate that the model can contribute valuable insights into the physics of an air plasma discharge.
基金We are grateful for the financial support from the National Natural Science Foundation of China （Nos. 20834006, 51073069, 51273078）, the Ministry of Sci- ence and Technology of China （No. 2009CB623605）, 111 project （No. B06009） and PCSIRT.
文摘The molecular materials with structures of luminescent core and peripheral carrier groups （e.g. carbazoles）, have exhibited high-performance in organic light-emitting diodes （OLEDs）. Present work is to understand the basic process of electronic and energy exchange between the peripheral functional groups and the central core through quantum chemical analysis. As an example, 4,7-bis（9,9-bis（6-（9H-carbazol-9-yl）hexyl）-9H-fluoren-2-yl）benzo[c]- [1,2,5]thiadiazole （TCBzC） is investigated in regards to optoelectronic properties using density functional theory （DFT）. The results suggest that the forbidden transition from peripheral carbazole to the central chromophore core makes for separated electrical and optical properties, and high performance electroluminescence （EL） is mainly at- tributed to the energy-transfer from carbazoles to the fluorene derivative core.
