For their distinguished global warming potential（GWP100）and long atmosphere lifespan,CF_4,SF_6 and SF_5CF_3were significant in the field of greenhouse gas research.The details of discharging character and the optima...For their distinguished global warming potential（GWP100）and long atmosphere lifespan,CF_4,SF_6 and SF_5CF_3were significant in the field of greenhouse gas research.The details of discharging character and the optimal parameter were discussed by using a Dielectric Barrier Discharge（DBD）reactor to decompose these potent greenhouse gases in this work.The results showed that SF_6 could be decomposed by 92% under the conditions of 5 min resident time and3000 V applied voltage with the partial pressure of 2.0 k Pa,28.2 k Pa,and 1.8 k Pa for SF_6,air and water vapor,respectively.0.4 k Pa CF_4 could be decomposed by 98.2% for 4 min resident time with 30 k Pa Ar added.The decomposition of SF_5CF_3 was much more effective than that of SF_6 and CF_4and moreover,1.3 k Pa SF_5CF_3,discharged with 30 k PaO_2,Ar and air,could not be detected when the resident time was 80 s,40 s,and 120 s,respectively.All the results indicated that DBD was a feasible technique for the abatement of potent greenhouse gases.展开更多
This paper presents the results of numerical investigation of the current pulses characteristics in SF_(6)/CF_(4)mixtures for the negative point-plane corona discharge.The pressure and the temperature of gas mixtures ...This paper presents the results of numerical investigation of the current pulses characteristics in SF_(6)/CF_(4)mixtures for the negative point-plane corona discharge.The pressure and the temperature of gas mixtures are 0.4 MPa and 300 K,respectively.The CF_(4)content varies from20%to 80%.The 2D axisymmetric geometry with point-plane electrodes is investigated,and the three drift-diffusion equations are solved to predict the characteristics of the negative corona discharge.In addition,Poisson’s equation is coupled with the above three continuity equations to calculate the electric field.In order to calculate the electron impact coefficients,including the Townsend ionization and attachment coefficients,as well as the mobilities and diffusion coefficients for electrons,the two-term Boltzmann equation is solved.The characteristics of three ionic species at five stages of the first current pulse in 60%SF_(6)-40%CF_(4)and20%SF_(6)-80%CF_(4)mixtures are selected to discuss the development mechanism of current pulses.Moreover,the reduced electric field strengths at the corresponding time instants are presented to help understand the discharge process.The current waveform and the total number of three species are compared in all the cases to analyze the effects of the CF_(4)content on the discharge.The reduced electric field strength is also helpful in understanding the effects of CF_(4)content.When the CF_(4)content increases to 80%,the discharge is more intensive and the pulse frequency also increases.展开更多
Plasma-induced surface graft copolymerization of acrylic acid on polypropylene non-woven fabric(PP-g-AA)andpolypropylene membrane were reported.The extents of grafting were controlled by the plasma and polymerizationc...Plasma-induced surface graft copolymerization of acrylic acid on polypropylene non-woven fabric(PP-g-AA)andpolypropylene membrane were reported.The extents of grafting were controlled by the plasma and polymerizationcondition.Hexadecyltrimethyl ammonium bromide was then coupled with the carboxyl group of PP-g-AA to obtain apolyion complex(PIC).At last,CF_4 plasma was used to give PICs hydrophobic property.The moisture regain and water-repellency of the processed PICs was investigated.The surfaces were characterized using ATR FT-IR and XPS.The resultindicates that the products have very high ability to adsorb moisture,even better than cotton fiber.At the same time,theproducts show excellent hydrophobic property,which can't be wetted by those reagents whose surface tensions were higherthan 327 mN/m.展开更多
Common insulation gas cannot normally work in refrigeration temperature range(153-243 K), especially in extremely cold regions. To solve this problem, this essay uses cubic equation combined with two-parameter model i...Common insulation gas cannot normally work in refrigeration temperature range(153-243 K), especially in extremely cold regions. To solve this problem, this essay uses cubic equation combined with two-parameter model in theorem of corresponding states to estimate dew-point of hybrid gas. The influence of temperature on mixing ratio is studied by using van der Waals equation. The result shows that the mixing ratio is stable during temperature-fall period. Insulation property of CF_4 and CF_4/N_2 in refrigeration temperature range is studied through self-designed low-temperature test system. The result shows when the density of hybrid gas is invariable, temperature changing has less influence on breakdown voltage, and when the mixing ratio is 20%, CF_4/N_2 is the greatest potential hybrid gas.展开更多
基金supported by National Natural Science Foundation of China(Nos.20507004,21577023)
文摘For their distinguished global warming potential（GWP100）and long atmosphere lifespan,CF_4,SF_6 and SF_5CF_3were significant in the field of greenhouse gas research.The details of discharging character and the optimal parameter were discussed by using a Dielectric Barrier Discharge（DBD）reactor to decompose these potent greenhouse gases in this work.The results showed that SF_6 could be decomposed by 92% under the conditions of 5 min resident time and3000 V applied voltage with the partial pressure of 2.0 k Pa,28.2 k Pa,and 1.8 k Pa for SF_6,air and water vapor,respectively.0.4 k Pa CF_4 could be decomposed by 98.2% for 4 min resident time with 30 k Pa Ar added.The decomposition of SF_5CF_3 was much more effective than that of SF_6 and CF_4and moreover,1.3 k Pa SF_5CF_3,discharged with 30 k PaO_2,Ar and air,could not be detected when the resident time was 80 s,40 s,and 120 s,respectively.All the results indicated that DBD was a feasible technique for the abatement of potent greenhouse gases.
基金Natural Science Foundation of Shaanxi Provincial Department of Education(No.21JK0792)National Natural Science Foundation of China(No.51521065)+1 种基金National Key Basic Research Program of China(973 Program)(No.2015CB251001)the Natural Sciences and Engineering Research Council of Canada(NSERC).
文摘This paper presents the results of numerical investigation of the current pulses characteristics in SF_(6)/CF_(4)mixtures for the negative point-plane corona discharge.The pressure and the temperature of gas mixtures are 0.4 MPa and 300 K,respectively.The CF_(4)content varies from20%to 80%.The 2D axisymmetric geometry with point-plane electrodes is investigated,and the three drift-diffusion equations are solved to predict the characteristics of the negative corona discharge.In addition,Poisson’s equation is coupled with the above three continuity equations to calculate the electric field.In order to calculate the electron impact coefficients,including the Townsend ionization and attachment coefficients,as well as the mobilities and diffusion coefficients for electrons,the two-term Boltzmann equation is solved.The characteristics of three ionic species at five stages of the first current pulse in 60%SF_(6)-40%CF_(4)and20%SF_(6)-80%CF_(4)mixtures are selected to discuss the development mechanism of current pulses.Moreover,the reduced electric field strengths at the corresponding time instants are presented to help understand the discharge process.The current waveform and the total number of three species are compared in all the cases to analyze the effects of the CF_(4)content on the discharge.The reduced electric field strength is also helpful in understanding the effects of CF_(4)content.When the CF_(4)content increases to 80%,the discharge is more intensive and the pulse frequency also increases.
文摘Plasma-induced surface graft copolymerization of acrylic acid on polypropylene non-woven fabric(PP-g-AA)andpolypropylene membrane were reported.The extents of grafting were controlled by the plasma and polymerizationcondition.Hexadecyltrimethyl ammonium bromide was then coupled with the carboxyl group of PP-g-AA to obtain apolyion complex(PIC).At last,CF_4 plasma was used to give PICs hydrophobic property.The moisture regain and water-repellency of the processed PICs was investigated.The surfaces were characterized using ATR FT-IR and XPS.The resultindicates that the products have very high ability to adsorb moisture,even better than cotton fiber.At the same time,theproducts show excellent hydrophobic property,which can't be wetted by those reagents whose surface tensions were higherthan 327 mN/m.
基金Project(51277063)supported by the National Natural Science Foundation of China
文摘Common insulation gas cannot normally work in refrigeration temperature range(153-243 K), especially in extremely cold regions. To solve this problem, this essay uses cubic equation combined with two-parameter model in theorem of corresponding states to estimate dew-point of hybrid gas. The influence of temperature on mixing ratio is studied by using van der Waals equation. The result shows that the mixing ratio is stable during temperature-fall period. Insulation property of CF_4 and CF_4/N_2 in refrigeration temperature range is studied through self-designed low-temperature test system. The result shows when the density of hybrid gas is invariable, temperature changing has less influence on breakdown voltage, and when the mixing ratio is 20%, CF_4/N_2 is the greatest potential hybrid gas.
