We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field streng...We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field strengths are decided by a balance of electron generation and loss based on chemical reactions estimated by the electron energy distribution function （EEDF）, which employs the Boltzmann equation method with two-term expanding approximation in the steady-state Townsend （SST） condition. During the insulation recovery phase, the hot CF3I/CO2 gas mixtures have maximum dielectric strength at a temperature of about 1500 K. At room temperature 300 K, the electric strength after arc extinction （90.3 Td, 1 Td=10-21 V.m2） is only 38% of the original value before arc （234.9 Td）. The adverse insulation recovery ability of CF3I/CO2 gas mixtures in arc extinction hinders its application in electric circuit breakers and other switchgears as an arc quenching and insulating medium.展开更多
The field emission （FE） characteristics of nano-structured carbon films （NSCFs） are investigated. The saturation behaviour of the field emission current density found at high electric field E cannot be reasonably ...The field emission （FE） characteristics of nano-structured carbon films （NSCFs） are investigated. The saturation behaviour of the field emission current density found at high electric field E cannot be reasonably explained by the traditional Fowler-Nordheim （F-N） theory. A three-region E model and the curve-fitting method are utilized for discussing the FE characteristics of NSCFs. In the low, high, and middle E regions, the FE mechanism is reasonably explained by a modified F-N model, a corrected space-charge-limited-current （SCLC） model and the joint model of F N and SCLC mechanism, respectively. Moreover, the measured FE data accord well with the results from our corrected theoretical model.展开更多
Since decades,the global electricity demand shows only one direction：a considerable constant increase every year.But the unlimited growth in energy consumption is discussed increasingly critical,not only primarily in...Since decades,the global electricity demand shows only one direction：a considerable constant increase every year.But the unlimited growth in energy consumption is discussed increasingly critical,not only primarily in terms of limitations but also in terms of more efficient,more intelligent,and more sustainable usage of energy.Energy-efficient technologies（EET）and renewable energy technologies are already in a competitive position in different markets,and they are also activelyembedded in scientific research. Meanwhile, enormous research on key points, such as smart home, smart cities, smart environments, and smart living in general, have been executed. Applying EET to improve human well-being and to reduce energy and resource consumption is on focus.展开更多
基金supported by National Natural Science Foundation of China(No.10875093)
文摘We calculated the uniform dielectric breakdown field strength of residual 30% CF3I/CO2 gas mixtures during the arc extinction process over the temperature range 300-3500 K at 0.1 MPa. The limiting reduced field strengths are decided by a balance of electron generation and loss based on chemical reactions estimated by the electron energy distribution function （EEDF）, which employs the Boltzmann equation method with two-term expanding approximation in the steady-state Townsend （SST） condition. During the insulation recovery phase, the hot CF3I/CO2 gas mixtures have maximum dielectric strength at a temperature of about 1500 K. At room temperature 300 K, the electric strength after arc extinction （90.3 Td, 1 Td=10-21 V.m2） is only 38% of the original value before arc （234.9 Td）. The adverse insulation recovery ability of CF3I/CO2 gas mixtures in arc extinction hinders its application in electric circuit breakers and other switchgears as an arc quenching and insulating medium.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11164031)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China (Grant No. (2009)1341)
文摘The field emission （FE） characteristics of nano-structured carbon films （NSCFs） are investigated. The saturation behaviour of the field emission current density found at high electric field E cannot be reasonably explained by the traditional Fowler-Nordheim （F-N） theory. A three-region E model and the curve-fitting method are utilized for discussing the FE characteristics of NSCFs. In the low, high, and middle E regions, the FE mechanism is reasonably explained by a modified F-N model, a corrected space-charge-limited-current （SCLC） model and the joint model of F N and SCLC mechanism, respectively. Moreover, the measured FE data accord well with the results from our corrected theoretical model.
文摘Since decades,the global electricity demand shows only one direction：a considerable constant increase every year.But the unlimited growth in energy consumption is discussed increasingly critical,not only primarily in terms of limitations but also in terms of more efficient,more intelligent,and more sustainable usage of energy.Energy-efficient technologies（EET）and renewable energy technologies are already in a competitive position in different markets,and they are also activelyembedded in scientific research. Meanwhile, enormous research on key points, such as smart home, smart cities, smart environments, and smart living in general, have been executed. Applying EET to improve human well-being and to reduce energy and resource consumption is on focus.
