In this study,ammonia emissions characteristics of typical light-duty gasoline vehicles were obtained through laboratory vehicle bench test and combined with New European Driving Cycle(NEDC)condition and Worldwide Har...In this study,ammonia emissions characteristics of typical light-duty gasoline vehicles were obtained through laboratory vehicle bench test and combined with New European Driving Cycle(NEDC)condition and Worldwide Harmonized Light Vehicles Test Cycle(WLTC)condition.The influence of ambient temperature on ammonia emissions is mainly concentrated in the cold start stage.The influence of ambient temperature on ammonia emission is shown that the ammonia emissions of light-duty gasoline vehicles under ambient temperature conditions(14 and 23℃)are lower than those under low ambient temperature conditions(-7℃)and high ambient temperature conditions(35 and 40℃).The influence of TWC on ammonia emission is shown that ammonia is a by-product of the catalytic reduction reaction of conventional gas pollutants in the exhaust gas in the TWC.Under NEDC operating conditions and WLTC operating conditions,ammonia emissions after the catalyst are 45 times and 72 times that before the catalyst,respectively.In terms of ammonia emissions control strategy research,Pd/Rh combination can reduce NH3 formation more effectively than catalyst with a single Pd formula.Precise control of the engine’s air-fuel ratio and combination with the optimized matched precious metal ratio TWC can effectively reduce ammonia emissions.展开更多
A novel nanocomposite of Ni nanoparticles loaded on Mg-doped Al_(2)O_(3)(Ni/Mg-Al_(2)O_(3))was prepared.By photothermocatalytic CO_(2) reduction with methane(CRM)merely using focused UV-vis-IR illumination on Ni/Mg-Al...A novel nanocomposite of Ni nanoparticles loaded on Mg-doped Al_(2)O_(3)(Ni/Mg-Al_(2)O_(3))was prepared.By photothermocatalytic CO_(2) reduction with methane(CRM)merely using focused UV-vis-IR illumination on Ni/Mg-Al_(2)O_(3),high production rates of H_(2)(r_(H2),69.71 mmol min^(−1) g^(−1))and CO(rCO,74.57 mmol min^(−1) g^(−1))and an extremely large light-to-fuel efficiency(η,32.9%)are acquired.High rH2 and rCO(51.07 and 59.66 mmol min^(−1) g^(−1))and a largeη(32.5%)are acquired even by using focusedλ>560 nm vis-IR illumination.Ni/Mg-Al_(2)O_(3) shows good durability for photothermocatalytic CRM due to the side reaction of carbon deposition being enormously inhibited in comparison with a reference catalyst of Ni nanoparticles loaded on Al_(2)O_(3).The enormous carbon deposition inhibition is ascribed to the presence of a fence of CO_(2) molecules(strongly adsorbed on Mg-doped Al_(2)O_(3))around Ni nanoparticles,which block the polymerization and growth of carbon species to nanofibers by promoting the oxidation of carbon species formed by CH_(4) dissociation.The high photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) arises from efficient light-driven thermocatalytic CRM.A photoactivation is found to considerably raise the photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) because of the apparent activation energy(Ea)being substantially decreased upon focused illumination.The Ea reduction is associated with the rate-determining steps of CRM(e.g.,CH_(4) dissociation and the oxidation of carbon species)being accelerated upon focused illumination.展开更多
The use of high-power lights during night-time purse seining is common in Vietnam.Typically,metal halide(MH)lamps are used in the commercial fishery to attract fish,however these lights require more energy,have a shor...The use of high-power lights during night-time purse seining is common in Vietnam.Typically,metal halide(MH)lamps are used in the commercial fishery to attract fish,however these lights require more energy,have a shorter lifespan,and lower chromatic performance than light emitting diode(LED)lamps.This study examined catch efficiency and fuel consumption when using LED lamps in combination with reduced numbers of MH lamps(10.24 kW),compared to conventional lighting(28.6 kW),used during purse seining off the coast of Ninh Thuan province,Vietnam.The economic performance associated with using LED lamps in this fishery was also assessed.We found no significant differences in catch rates between the different light treatments,however fuel consumption was significantly reduced.Fuel consumption per nightly trip using LED with MH lamps was 70.8 l(11.1 l/h)compared to114 l(17.45 l/hr)using MH lamps alone,an estimated 37.9%reduction in fuel consumption.An investment in LED lamps by a fishing enterprise will require additional initial costs,however our analysis revealed the financial break-event point can be reached after approximately 101 nightly trips when the fuel price is at the 2015 level of USD$0.74 per l.Fishing enterprises can increase their profitability,and reduce CO2 emissions,by using LED lamps in the Vietnamese purse seine fishery.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51508304 and 41275133)。
文摘In this study,ammonia emissions characteristics of typical light-duty gasoline vehicles were obtained through laboratory vehicle bench test and combined with New European Driving Cycle(NEDC)condition and Worldwide Harmonized Light Vehicles Test Cycle(WLTC)condition.The influence of ambient temperature on ammonia emissions is mainly concentrated in the cold start stage.The influence of ambient temperature on ammonia emission is shown that the ammonia emissions of light-duty gasoline vehicles under ambient temperature conditions(14 and 23℃)are lower than those under low ambient temperature conditions(-7℃)and high ambient temperature conditions(35 and 40℃).The influence of TWC on ammonia emission is shown that ammonia is a by-product of the catalytic reduction reaction of conventional gas pollutants in the exhaust gas in the TWC.Under NEDC operating conditions and WLTC operating conditions,ammonia emissions after the catalyst are 45 times and 72 times that before the catalyst,respectively.In terms of ammonia emissions control strategy research,Pd/Rh combination can reduce NH3 formation more effectively than catalyst with a single Pd formula.Precise control of the engine’s air-fuel ratio and combination with the optimized matched precious metal ratio TWC can effectively reduce ammonia emissions.
基金supported by National Natural Science Foundation of China(21972109,21673168)DFT calculations were conducted at the Shanghai Supercomputer Center(SSC),China.
文摘A novel nanocomposite of Ni nanoparticles loaded on Mg-doped Al_(2)O_(3)(Ni/Mg-Al_(2)O_(3))was prepared.By photothermocatalytic CO_(2) reduction with methane(CRM)merely using focused UV-vis-IR illumination on Ni/Mg-Al_(2)O_(3),high production rates of H_(2)(r_(H2),69.71 mmol min^(−1) g^(−1))and CO(rCO,74.57 mmol min^(−1) g^(−1))and an extremely large light-to-fuel efficiency(η,32.9%)are acquired.High rH2 and rCO(51.07 and 59.66 mmol min^(−1) g^(−1))and a largeη(32.5%)are acquired even by using focusedλ>560 nm vis-IR illumination.Ni/Mg-Al_(2)O_(3) shows good durability for photothermocatalytic CRM due to the side reaction of carbon deposition being enormously inhibited in comparison with a reference catalyst of Ni nanoparticles loaded on Al_(2)O_(3).The enormous carbon deposition inhibition is ascribed to the presence of a fence of CO_(2) molecules(strongly adsorbed on Mg-doped Al_(2)O_(3))around Ni nanoparticles,which block the polymerization and growth of carbon species to nanofibers by promoting the oxidation of carbon species formed by CH_(4) dissociation.The high photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) arises from efficient light-driven thermocatalytic CRM.A photoactivation is found to considerably raise the photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) because of the apparent activation energy(Ea)being substantially decreased upon focused illumination.The Ea reduction is associated with the rate-determining steps of CRM(e.g.,CH_(4) dissociation and the oxidation of carbon species)being accelerated upon focused illumination.
文摘The use of high-power lights during night-time purse seining is common in Vietnam.Typically,metal halide(MH)lamps are used in the commercial fishery to attract fish,however these lights require more energy,have a shorter lifespan,and lower chromatic performance than light emitting diode(LED)lamps.This study examined catch efficiency and fuel consumption when using LED lamps in combination with reduced numbers of MH lamps(10.24 kW),compared to conventional lighting(28.6 kW),used during purse seining off the coast of Ninh Thuan province,Vietnam.The economic performance associated with using LED lamps in this fishery was also assessed.We found no significant differences in catch rates between the different light treatments,however fuel consumption was significantly reduced.Fuel consumption per nightly trip using LED with MH lamps was 70.8 l(11.1 l/h)compared to114 l(17.45 l/hr)using MH lamps alone,an estimated 37.9%reduction in fuel consumption.An investment in LED lamps by a fishing enterprise will require additional initial costs,however our analysis revealed the financial break-event point can be reached after approximately 101 nightly trips when the fuel price is at the 2015 level of USD$0.74 per l.Fishing enterprises can increase their profitability,and reduce CO2 emissions,by using LED lamps in the Vietnamese purse seine fishery.
