Reaction resonance or Feshbach resonance in polyatomic reaction is one of the most fascinating phenomena in chemical reaction dynamics. The HO+CH4→HO+CH3 reaction is one of the pivotal polyato-mic reactions concerned...Reaction resonance or Feshbach resonance in polyatomic reaction is one of the most fascinating phenomena in chemical reaction dynamics. The HO+CH4→HO+CH3 reaction is one of the pivotal polyato-mic reactions concerned with both the experimental and theoretical scientists. Reaction probabilities and other dynamic properties of this system were calculated with quantum scattering theory method, but a simple QH(v)+HO(j)→Q+H2O(m,n) reaction model was used, in which only three degrees of freedom and the rotating of OH were considered while making CH3 as a pseudo atom. In this paper, by an ab initio method, partial potential energy surface(PPES) was constructed and all the 15 internal degrees-freedom were given. Feshbach resonance mechanism of this reaction can be obtained by the dynamic Eyring Lake on the PPES and the lifetime of the reactive resonance-state can be estimated using the gap of the vibrational energy levels of transient collision complex in the critical transition-state region. Above interesting dynamic properties would not be given by simple pseudo atomic reaction model.展开更多
Y2O2S:Yb/Ho-silica/aminosilane core-shell nanoparticles were prepared by a solid-gas method in combination with polyvinylpyr-rolidone assisted one-step ammoniating method. The core was a single Y2O2S:Yb/Ho with 80 nm ...Y2O2S:Yb/Ho-silica/aminosilane core-shell nanoparticles were prepared by a solid-gas method in combination with polyvinylpyr-rolidone assisted one-step ammoniating method. The core was a single Y2O2S:Yb/Ho with 80 nm in diameter and the shell was silica/aminosilane with around 5 nm in thickness. The results of sedimentation experiment indicated that the nanoparticles could be well-dispersed in ethanol and water to form stable colloids. Since the coating weakened lattice vibration energies of the Y2O2S:Yb/Ho...展开更多
The strong yellow upconversion （UC） light emission was observed in Ho3＋/yb3＋ co-doped Gd2M0309 phosphor under the excitation of 980 nm diode laser. The phosphors were synthesized by the traditional solid-state rea...The strong yellow upconversion （UC） light emission was observed in Ho3＋/yb3＋ co-doped Gd2M0309 phosphor under the excitation of 980 nm diode laser. The phosphors were synthesized by the traditional solid-state reaction method. The structures of the samples were characterized by X-ray diffraction （XRD）. Under 980 nm excitation, Ho3＋/yb3＋ co-doped Gd2Mo3O9 exhibited strong yellow UC emission based on the green emission near 541 nm generated by 5F4,5S2→5i8 transition and the strong red emission around 660 nm generated by 5F5→5I8 transition, which assigned to the intra-4f transitions of Ho3＋ ions. The doping concentrations of Ho3＋ and Yb3＋ were determined to be 0.01 mol Ho3＋ and 0.2 mol Yb3＋ for the strongest yellow emission. Then the dependence of UC emis- sion intensity on excitation power density showed that the green and red UC emissions were involved in two-photon process. The possible UC mechanisms for the strong yellow emission were also investigated. The result indicated that this material was a promis- ing candidate for the application in the yellow display field.展开更多
Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temper...Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temperature range,the heat capacities increased in a smooth and continuous manner and no phase transition or thermal anomaly occurred.Therefore,the sample was stable in the above temperature range.The values of experimental heat capacities were fitted to a polynomial equation with least square method and ...展开更多
文摘Reaction resonance or Feshbach resonance in polyatomic reaction is one of the most fascinating phenomena in chemical reaction dynamics. The HO+CH4→HO+CH3 reaction is one of the pivotal polyato-mic reactions concerned with both the experimental and theoretical scientists. Reaction probabilities and other dynamic properties of this system were calculated with quantum scattering theory method, but a simple QH(v)+HO(j)→Q+H2O(m,n) reaction model was used, in which only three degrees of freedom and the rotating of OH were considered while making CH3 as a pseudo atom. In this paper, by an ab initio method, partial potential energy surface(PPES) was constructed and all the 15 internal degrees-freedom were given. Feshbach resonance mechanism of this reaction can be obtained by the dynamic Eyring Lake on the PPES and the lifetime of the reactive resonance-state can be estimated using the gap of the vibrational energy levels of transient collision complex in the critical transition-state region. Above interesting dynamic properties would not be given by simple pseudo atomic reaction model.
基金Project supported by the National Natural Science Foundation of China (60979003 and 20977012)
文摘Y2O2S:Yb/Ho-silica/aminosilane core-shell nanoparticles were prepared by a solid-gas method in combination with polyvinylpyr-rolidone assisted one-step ammoniating method. The core was a single Y2O2S:Yb/Ho with 80 nm in diameter and the shell was silica/aminosilane with around 5 nm in thickness. The results of sedimentation experiment indicated that the nanoparticles could be well-dispersed in ethanol and water to form stable colloids. Since the coating weakened lattice vibration energies of the Y2O2S:Yb/Ho...
基金Project supported by National Natural Science Foundation of China (20976002)Beijing Municipal Natural Science Foundation(2122012)+2 种基金Key Projects for Science and Technology of Beijing Education Commission (KZ201310011013)Project of Transformation and Industrialization of College Scientific & Technological AchievementsProjects of the Combination of Manufacture,Education & Research of Guangdong Province (2011B090400100)
文摘The strong yellow upconversion （UC） light emission was observed in Ho3＋/yb3＋ co-doped Gd2M0309 phosphor under the excitation of 980 nm diode laser. The phosphors were synthesized by the traditional solid-state reaction method. The structures of the samples were characterized by X-ray diffraction （XRD）. Under 980 nm excitation, Ho3＋/yb3＋ co-doped Gd2Mo3O9 exhibited strong yellow UC emission based on the green emission near 541 nm generated by 5F4,5S2→5i8 transition and the strong red emission around 660 nm generated by 5F5→5I8 transition, which assigned to the intra-4f transitions of Ho3＋ ions. The doping concentrations of Ho3＋ and Yb3＋ were determined to be 0.01 mol Ho3＋ and 0.2 mol Yb3＋ for the strongest yellow emission. Then the dependence of UC emis- sion intensity on excitation power density showed that the green and red UC emissions were involved in two-photon process. The possible UC mechanisms for the strong yellow emission were also investigated. The result indicated that this material was a promis- ing candidate for the application in the yellow display field.
基金supported by the National Natural Science Foundation of China(20373072,20753002)
文摘Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temperature range,the heat capacities increased in a smooth and continuous manner and no phase transition or thermal anomaly occurred.Therefore,the sample was stable in the above temperature range.The values of experimental heat capacities were fitted to a polynomial equation with least square method and ...
