The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^...The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^(2+),O_(2)^(2+)O^(+),O^(2+),and their total)and two Coulomb explosion channels(O^(+)+O^(+)and O^(2+)+O^(+))are obtained by putting the data of O^(2+)on the scale of Ar+from O_(2)and Ar gases mixed with a fixed relative flow ratio of 1:1.The experimental errors are assessed by taking uncertainties of various factors into account.The present absolute cross sections are well consistent with the previous data in the overlapped energy range below 1000 eV.展开更多
Chalcopyrite is a common copper-bearing mineral with antiferromagnetic properties.However,this property has rarely been considered in previous studies for detailed adsorption behaviors of molecules on chalcopyrite.Bas...Chalcopyrite is a common copper-bearing mineral with antiferromagnetic properties.However,this property has rarely been considered in previous studies for detailed adsorption behaviors of molecules on chalcopyrite.Based on density functional theory(DFT),new adsorption pathways by H_(2)O and O_(2)on the chalcopyrite metal terminated(112)surface((112)-M)is found in this work.First,through simulating the adsorption of an isolated water molecule and monolayer water molecules,it is confirmed that H_(2)O molecules tend to adsorb on the surface Fe atoms more than on the surface Cu atoms.Then,we studied various adsorption behaviors of the O_(2)molecule.It is found that the adsorption on the hollow FeAFe site is the most stable case;however,O_(2)is undissociated.Two adsorption cases will happen when H_(2)OAO_(2)adsorb simultaneously on the surface.For the S site,the H_(2)O molecule thoroughly dissociated and formed SAO species,and the other case is H_(2)O undissociated adsorbing at the Cu site.For the former case,it is interesting that H_(2)O is dissociated before O_(2).展开更多
Iron(Ⅱ)tetra-(1,4-dithin)-porphyrazine,(FePz(dtn)_(4))is able to activate molecule oxygen for oxygenation degradation of rhodamine B(RhB)in an extensive pH region without light excitation.Experiments indicate that th...Iron(Ⅱ)tetra-(1,4-dithin)-porphyrazine,(FePz(dtn)_(4))is able to activate molecule oxygen for oxygenation degradation of rhodamine B(RhB)in an extensive pH region without light excitation.Experiments indicate that the RhB can be degraded nearly 52%in alkaline aqueous solution,bubbling with dioxygen for seven hours in the presence of FePz(dtn)_(4)and the hydrogen peroxides as an active intermediate were determined by DPD method.The catalyst is recyclable and the catalyst activity was maintained after 10 recycles.展开更多
We study the binding of molecular oxygen to a （5, 0） single walled SiC nanotube, by means of density functional calculations. The center of a hexagon of silicon and carbon atoms in sites on SiCNT surfaces is the mos...We study the binding of molecular oxygen to a （5, 0） single walled SiC nanotube, by means of density functional calculations. The center of a hexagon of silicon and carbon atoms in sites on SiCNT surfaces is the most stable adsorption site for 02 molecule, with a binding energy of -38.22 eV and an average Si-O binding distance of 1.698 A. We have also tested the stability of the 02-adsorbed SiCNT/CNT with ab initio molecular dynamics simulation which have been carried out at room temperature. Furthermore, the adsorption of 02 on the single walled carbon nanotubes has been investigated. Our first-principles calculations predict that the 02 adsorptive capability of silicon carbide nanotubes is much better than that of carbon nanotubes. This might have potential for gas detection and energy storage.展开更多
The Doppler-limited absorption spectrum of 16O2^＋ cation was observed in the region of 11385-12100 cm^-1 by optical heterodyne velocity modulation absorption spectroscopy （OH-VMS）. The transitions were assigned to ...The Doppler-limited absorption spectrum of 16O2^＋ cation was observed in the region of 11385-12100 cm^-1 by optical heterodyne velocity modulation absorption spectroscopy （OH-VMS）. The transitions were assigned to the （2, 19）, （3, 20）, and （5, 21） bands in the second negative system （A^2∏u-X^2∏g）. All the available lines measured using OH-VMS were global fitted in a nonlinear least-squares fitting procedure, and precise molecular constants （Bv, Av, Dv, pv, qv, γv） were obtained for the involved levels.展开更多
The microstructure modifications of sodium silicate glass induced by 1.2-MeV electron irradiation are studied by x-ray photoelectron spectroscopy and Raman spectroscopy. Depth profile analyses are also performed on th...The microstructure modifications of sodium silicate glass induced by 1.2-MeV electron irradiation are studied by x-ray photoelectron spectroscopy and Raman spectroscopy. Depth profile analyses are also performed on the irradiated glass at 109 Gy. A sodium-depleted layer with a thickness of a few tens of nanometers and the corresponding increase of network polymerization on the top surface are observed after electron bombardment, while the polymerization in the subsurface region has a negligible variation with the irradiation dose. Moreover, the formation of molecular oxygen after electron irradiation is evidenced, which is mainly aggregated in the first two-micron-thick irradiated glass surface. These modifications are correlated to the network relaxation process as a consequence of the diffusion and desorption of sodium species during electron irradiation.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1602502)the National Natural Science Foundation of China(No.12127804).
文摘The direct and dissociative ionizations of oxygen molecule are investigated experimen-tally by electron collision with energies from 350 eV to 8000 eV.The absolute ionization cross sections for the product ions(O_(2)^(2+),O_(2)^(2+)O^(+),O^(2+),and their total)and two Coulomb explosion channels(O^(+)+O^(+)and O^(2+)+O^(+))are obtained by putting the data of O^(2+)on the scale of Ar+from O_(2)and Ar gases mixed with a fixed relative flow ratio of 1:1.The experimental errors are assessed by taking uncertainties of various factors into account.The present absolute cross sections are well consistent with the previous data in the overlapped energy range below 1000 eV.
基金The authors are grateful for the financial support provided by the National Natural Science Foundation of China(NSFC)(Nos.51974094,51964004,and U20A20269).
文摘Chalcopyrite is a common copper-bearing mineral with antiferromagnetic properties.However,this property has rarely been considered in previous studies for detailed adsorption behaviors of molecules on chalcopyrite.Based on density functional theory(DFT),new adsorption pathways by H_(2)O and O_(2)on the chalcopyrite metal terminated(112)surface((112)-M)is found in this work.First,through simulating the adsorption of an isolated water molecule and monolayer water molecules,it is confirmed that H_(2)O molecules tend to adsorb on the surface Fe atoms more than on the surface Cu atoms.Then,we studied various adsorption behaviors of the O_(2)molecule.It is found that the adsorption on the hollow FeAFe site is the most stable case;however,O_(2)is undissociated.Two adsorption cases will happen when H_(2)OAO_(2)adsorb simultaneously on the surface.For the S site,the H_(2)O molecule thoroughly dissociated and formed SAO species,and the other case is H_(2)O undissociated adsorbing at the Cu site.For the former case,it is interesting that H_(2)O is dissociated before O_(2).
基金supported by the NNSFC(No.29771025),(No.20377053)The Nine-five National Key Project of China(29833090)The Hubei Province Foundation of China(No.2003ABA071).
文摘Iron(Ⅱ)tetra-(1,4-dithin)-porphyrazine,(FePz(dtn)_(4))is able to activate molecule oxygen for oxygenation degradation of rhodamine B(RhB)in an extensive pH region without light excitation.Experiments indicate that the RhB can be degraded nearly 52%in alkaline aqueous solution,bubbling with dioxygen for seven hours in the presence of FePz(dtn)_(4)and the hydrogen peroxides as an active intermediate were determined by DPD method.The catalyst is recyclable and the catalyst activity was maintained after 10 recycles.
文摘We study the binding of molecular oxygen to a （5, 0） single walled SiC nanotube, by means of density functional calculations. The center of a hexagon of silicon and carbon atoms in sites on SiCNT surfaces is the most stable adsorption site for 02 molecule, with a binding energy of -38.22 eV and an average Si-O binding distance of 1.698 A. We have also tested the stability of the 02-adsorbed SiCNT/CNT with ab initio molecular dynamics simulation which have been carried out at room temperature. Furthermore, the adsorption of 02 on the single walled carbon nanotubes has been investigated. Our first-principles calculations predict that the 02 adsorptive capability of silicon carbide nanotubes is much better than that of carbon nanotubes. This might have potential for gas detection and energy storage.
基金ACKNOWLEDGMENTS This work was supported Science Foundation of China by the National Natural （No.11004062）.
文摘The Doppler-limited absorption spectrum of 16O2^＋ cation was observed in the region of 11385-12100 cm^-1 by optical heterodyne velocity modulation absorption spectroscopy （OH-VMS）. The transitions were assigned to the （2, 19）, （3, 20）, and （5, 21） bands in the second negative system （A^2∏u-X^2∏g）. All the available lines measured using OH-VMS were global fitted in a nonlinear least-squares fitting procedure, and precise molecular constants （Bv, Av, Dv, pv, qv, γv） were obtained for the involved levels.
文摘The microstructure modifications of sodium silicate glass induced by 1.2-MeV electron irradiation are studied by x-ray photoelectron spectroscopy and Raman spectroscopy. Depth profile analyses are also performed on the irradiated glass at 109 Gy. A sodium-depleted layer with a thickness of a few tens of nanometers and the corresponding increase of network polymerization on the top surface are observed after electron bombardment, while the polymerization in the subsurface region has a negligible variation with the irradiation dose. Moreover, the formation of molecular oxygen after electron irradiation is evidenced, which is mainly aggregated in the first two-micron-thick irradiated glass surface. These modifications are correlated to the network relaxation process as a consequence of the diffusion and desorption of sodium species during electron irradiation.
