The cubic S/N co-doped TiO_(2)(TNSx,x is the calcination temperature)photocatalysts with rich oxygen vacancies were obtained by high temperature calcination of sulfur powder and titanium-based MOFs NH_(2)-MIL-125 for ...The cubic S/N co-doped TiO_(2)(TNSx,x is the calcination temperature)photocatalysts with rich oxygen vacancies were obtained by high temperature calcination of sulfur powder and titanium-based MOFs NH_(2)-MIL-125 for the photocatalytic removal of gaseous formaldehyde(a volatile organic compound).Among the obtained catalysts,the presence of oxygen vacancies restricted photogenerated electron and holes recombination.98.00%removal of gaseous formaldehyde in 150 min could be achieved over TNS600 by xenon lamp.The removal efficiency for formaldehyde was well retained for five cycle experiment.The results from PL,TRPL and EIS revealed that TNS600 had the best separation efficiency of photogenerated electrons and holes,and the enhanced charge separation led to a significant increase in photocatalytic activity.The photocatalytic oxidation mechanism indicated that the ^(•)OH and ^(•)O_(2)−radicals were mainly involved in the efficient elimination of gaseous formaldehyde and were able to mineralize formaldehyde to H_(2)O and CO_(2).展开更多
The development of aqueous zinc-ion batteries (AZIBs) marks a significant advancement in the field of sustainable and environmentally friendly energy storage.To address the challenges faced by singlephase vanadium-bas...The development of aqueous zinc-ion batteries (AZIBs) marks a significant advancement in the field of sustainable and environmentally friendly energy storage.To address the challenges faced by singlephase vanadium-based oxides,such as poor conductivity and dissolution in electrolytes,this study introduces vacuum S/N doping to fabricate V_(2)O_(3)/VO_(2)@S/N-C nanofibers,improving the cycling stability and enhancing the capacity.The V_(2)O_(3)/VO_(2)@S/N-C electrode exhibits exceptional cyclic stability,retaining a capacity of 133.3 m A h g^(-1)after 30,000 cycles at a high current density of 100 A g^(-1)and a capacity retention of 81.8%after 150,000 cycles at 200 A g^(-1).Characterizations using ex-situ X-ray diffraction and ex-situ X-ray photoelectron spectroscopy reveal co-intercalation of H^(+)and Zn^(2+)in the V_(2)O_(3)/VO_(2)@S/N-C electrode.Due to the presence of S_(2)^(2-),more phases changed to V_(10)O_(24).12H_(2)O,making the V_(2)O_(3)/VO_(2)@S/N-C electrode better reversible.By elucidating the zinc storage mechanism and demonstrating the stable performance of the doped electrode,this work contributes valuable insights into the optimization of the electrode materials for future energy storage solutions.展开更多
Due to its larger ionic radius,further studies are needed before graphite can be used as an anode for sodium/potassium-ion batteries(SIBs/KIBs).It is believed that doping and increasing the layer spacing can improve t...Due to its larger ionic radius,further studies are needed before graphite can be used as an anode for sodium/potassium-ion batteries(SIBs/KIBs).It is believed that doping and increasing the layer spacing can improve the Na+/K+storage.Herein,S/N co-doped graphite nanosheets(GNS)with an enlarged interlayer spacing of 0.39 nm were prepared via exfoliation with three-roll milling(TRM)combined with thiourea heated at different temperatures.This method generates abundant defects and active sites for GNS,as well as facilitates rapid access and transport of electrolytes and electrons/ions.The electrochemical results show that the S/N-doped GNS exfoliated 15 times and heated at 600°C(SNGNS15-600)with thiourea as the electrode delivers a discharge capacity of 94 mAh g–1 over 6000 cycles at 10 A g–1 with an enhanced rate capability and stable performance for application in SIBs.Calculations using density functional theory show that the increased interlayer spacing by TRM and S,N co-doping enhances the adsorption energies of Na+on graphite,thus improving the Na+storage.As the anode for KIBs,the SNGNS15-600 electrode has a capacity of 142 mAh g–1 after 5000 cycles at 0.5 A g–1.This study provides an essential theoretical basis for the effective exfoliation of layered graphite-based materials and their applications in energy storage.展开更多
The seismic data from western China is very noisy. Two main reasons are static corrections and low S/N ratio problems. By seismic data processing and study these problems have been effectively solved by iterating the ...The seismic data from western China is very noisy. Two main reasons are static corrections and low S/N ratio problems. By seismic data processing and study these problems have been effectively solved by iterating the static corrections and improving the S/N ratio for pre-stack seismic data. Suppression and elimination of various other distortions has been implemented as well. Due to the fact that the S/N ratio is improved, the resolution of the seismic data is also improved.展开更多
Using the quantitative error probability density method we studied the S/N ratio of alternately sampled signals digitized by a 4-channel A/D. A complete expression for the S/N ratio of a 4-channel A/D non-uniform samp...Using the quantitative error probability density method we studied the S/N ratio of alternately sampled signals digitized by a 4-channel A/D. A complete expression for the S/N ratio of a 4-channel A/D non-uniform sampling signal was deduced. First we obtained an expression for the S/N ratio of a 1-channel A/D uniform sampling signal when the sampling frequency was equal to or greater than 2 times the frequency of the sampled signal. Based on the S/N ratio of a 2-channel A/D,alternating,non-uniform sampling signal,we analyzed the distribution of quantitative error using the quantitative error probability density method and the distribution convolution formula. From this the S/N ratio expression of a 4-channel A/D sampling signal was deduced. The simulation result shows that the deduced expression is correct.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21876008 and 22276009).
文摘The cubic S/N co-doped TiO_(2)(TNSx,x is the calcination temperature)photocatalysts with rich oxygen vacancies were obtained by high temperature calcination of sulfur powder and titanium-based MOFs NH_(2)-MIL-125 for the photocatalytic removal of gaseous formaldehyde(a volatile organic compound).Among the obtained catalysts,the presence of oxygen vacancies restricted photogenerated electron and holes recombination.98.00%removal of gaseous formaldehyde in 150 min could be achieved over TNS600 by xenon lamp.The removal efficiency for formaldehyde was well retained for five cycle experiment.The results from PL,TRPL and EIS revealed that TNS600 had the best separation efficiency of photogenerated electrons and holes,and the enhanced charge separation led to a significant increase in photocatalytic activity.The photocatalytic oxidation mechanism indicated that the ^(•)OH and ^(•)O_(2)−radicals were mainly involved in the efficient elimination of gaseous formaldehyde and were able to mineralize formaldehyde to H_(2)O and CO_(2).
基金financially supported by the Natural Science Foundation of China (Grant No. 52272063)the Jiangxi Provincial Natural Science Foundation (No. 20224BAB214037, 20232BAB204022, 20232BAB204019)。
文摘The development of aqueous zinc-ion batteries (AZIBs) marks a significant advancement in the field of sustainable and environmentally friendly energy storage.To address the challenges faced by singlephase vanadium-based oxides,such as poor conductivity and dissolution in electrolytes,this study introduces vacuum S/N doping to fabricate V_(2)O_(3)/VO_(2)@S/N-C nanofibers,improving the cycling stability and enhancing the capacity.The V_(2)O_(3)/VO_(2)@S/N-C electrode exhibits exceptional cyclic stability,retaining a capacity of 133.3 m A h g^(-1)after 30,000 cycles at a high current density of 100 A g^(-1)and a capacity retention of 81.8%after 150,000 cycles at 200 A g^(-1).Characterizations using ex-situ X-ray diffraction and ex-situ X-ray photoelectron spectroscopy reveal co-intercalation of H^(+)and Zn^(2+)in the V_(2)O_(3)/VO_(2)@S/N-C electrode.Due to the presence of S_(2)^(2-),more phases changed to V_(10)O_(24).12H_(2)O,making the V_(2)O_(3)/VO_(2)@S/N-C electrode better reversible.By elucidating the zinc storage mechanism and demonstrating the stable performance of the doped electrode,this work contributes valuable insights into the optimization of the electrode materials for future energy storage solutions.
基金supported by the Natural Science Foundation of China(Nos.51862024 and 51962023)the Key Research and Development Program of Jiangxi Province(No.20203BBE53066).
文摘Due to its larger ionic radius,further studies are needed before graphite can be used as an anode for sodium/potassium-ion batteries(SIBs/KIBs).It is believed that doping and increasing the layer spacing can improve the Na+/K+storage.Herein,S/N co-doped graphite nanosheets(GNS)with an enlarged interlayer spacing of 0.39 nm were prepared via exfoliation with three-roll milling(TRM)combined with thiourea heated at different temperatures.This method generates abundant defects and active sites for GNS,as well as facilitates rapid access and transport of electrolytes and electrons/ions.The electrochemical results show that the S/N-doped GNS exfoliated 15 times and heated at 600°C(SNGNS15-600)with thiourea as the electrode delivers a discharge capacity of 94 mAh g–1 over 6000 cycles at 10 A g–1 with an enhanced rate capability and stable performance for application in SIBs.Calculations using density functional theory show that the increased interlayer spacing by TRM and S,N co-doping enhances the adsorption energies of Na+on graphite,thus improving the Na+storage.As the anode for KIBs,the SNGNS15-600 electrode has a capacity of 142 mAh g–1 after 5000 cycles at 0.5 A g–1.This study provides an essential theoretical basis for the effective exfoliation of layered graphite-based materials and their applications in energy storage.
文摘The seismic data from western China is very noisy. Two main reasons are static corrections and low S/N ratio problems. By seismic data processing and study these problems have been effectively solved by iterating the static corrections and improving the S/N ratio for pre-stack seismic data. Suppression and elimination of various other distortions has been implemented as well. Due to the fact that the S/N ratio is improved, the resolution of the seismic data is also improved.
基金Projects 07KJZ11 supported by the President Fund of Xuzhou Medical School07KJB310117 by the Education Department of Jiangsu Province
文摘Using the quantitative error probability density method we studied the S/N ratio of alternately sampled signals digitized by a 4-channel A/D. A complete expression for the S/N ratio of a 4-channel A/D non-uniform sampling signal was deduced. First we obtained an expression for the S/N ratio of a 1-channel A/D uniform sampling signal when the sampling frequency was equal to or greater than 2 times the frequency of the sampled signal. Based on the S/N ratio of a 2-channel A/D,alternating,non-uniform sampling signal,we analyzed the distribution of quantitative error using the quantitative error probability density method and the distribution convolution formula. From this the S/N ratio expression of a 4-channel A/D sampling signal was deduced. The simulation result shows that the deduced expression is correct.
