The Eu 3+ doped Na 24 As 2Mo 22 O 83 phosphor was prepared by solid state reaction from Na 3AsO 4·12H 2O?Na 2MoO 4·2H 2O and MoO 3,and characterized by using elemental analysis,infrared spectroscopy and powd...The Eu 3+ doped Na 24 As 2Mo 22 O 83 phosphor was prepared by solid state reaction from Na 3AsO 4·12H 2O?Na 2MoO 4·2H 2O and MoO 3,and characterized by using elemental analysis,infrared spectroscopy and powder X ray diffractometry.According to our measurements with X ray diffraction,this material belongs to orthorhombic system with its lattice contants:a=1.4824nm,b=1.1902nm,c=1.1042nm,that are consistent with space group D 4 2 P2 12 12 1(No.19).The emission and excitation spectra were also measured.The luminescence properties of Eu 3+ doped Na 24 As 2Mo 22 O 83 and energy transfer mechanism were discussed.展开更多
This paper describes the development and application of an intense slow positron beam at IHEP with regard to its two main components. The Variable-Energy Positron Lifetime Spectroscopy （VEPLS） based on the pulsing s...This paper describes the development and application of an intense slow positron beam at IHEP with regard to its two main components. The Variable-Energy Positron Lifetime Spectroscopy （VEPLS） based on the pulsing system consisting of a chopper, a prebuncher and a buncher has been constructed in order to meet the needs of materials science development. At present, the time resolution of the VEPLS can easily reach about 386 ps with a peak-to-background ratio of about 600：1. A plugged-in ^22Na positron source section for adjusting the newly built experimental station and for increasing the beam operation efficiency has been constructed. A slow positron beam with an intensity of 2.5×10^5 e^＋/s and the beam profile whose diameter is 10 mm has been obtained; the moderation efficiency of the tungsten mesh moderator reaches 5.1×10^-4 as calculated with an original positron source activity of 52 mCi.展开更多
The neutron induced reactions on ^23Na are investigated by using the Talys1.4 program. The calculated results for the ^23Na（n, 2n）22Na reaction are found to agree with the experimental results. The cross sections of...The neutron induced reactions on ^23Na are investigated by using the Talys1.4 program. The calculated results for the ^23Na（n, 2n）22Na reaction are found to agree with the experimental results. The cross sections of the residues of the（n, n）,（n, γ）,（n, p）, and（n, np） channels in the reactions are presented, and at the same time, the neutron induced reactions on22 Ne are also investigated.展开更多
In recent years the experiments of CERN-UA5 and NA22 Collaboration find that rapidity η-multiplicity N correlation is a visual scaling (s<sup>1/2</sup>=22—900 G-eV) and η<sub>cut</sub><su...In recent years the experiments of CERN-UA5 and NA22 Collaboration find that rapidity η-multiplicity N correlation is a visual scaling (s<sup>1/2</sup>=22—900 G-eV) and η<sub>cut</sub><sup>-</sup>N correlations are very complicated. These correlations may be helpful for building multihadron dynamics. We shall compare these data with the theory of quantum field at short展开更多
文摘The Eu 3+ doped Na 24 As 2Mo 22 O 83 phosphor was prepared by solid state reaction from Na 3AsO 4·12H 2O?Na 2MoO 4·2H 2O and MoO 3,and characterized by using elemental analysis,infrared spectroscopy and powder X ray diffractometry.According to our measurements with X ray diffraction,this material belongs to orthorhombic system with its lattice contants:a=1.4824nm,b=1.1902nm,c=1.1042nm,that are consistent with space group D 4 2 P2 12 12 1(No.19).The emission and excitation spectra were also measured.The luminescence properties of Eu 3+ doped Na 24 As 2Mo 22 O 83 and energy transfer mechanism were discussed.
基金Supported by National Natural Science Foundation of China (10475096,10575112)Special Fund for Equipment of Chinese Academy of Sciences (U-37)
文摘This paper describes the development and application of an intense slow positron beam at IHEP with regard to its two main components. The Variable-Energy Positron Lifetime Spectroscopy （VEPLS） based on the pulsing system consisting of a chopper, a prebuncher and a buncher has been constructed in order to meet the needs of materials science development. At present, the time resolution of the VEPLS can easily reach about 386 ps with a peak-to-background ratio of about 600：1. A plugged-in ^22Na positron source section for adjusting the newly built experimental station and for increasing the beam operation efficiency has been constructed. A slow positron beam with an intensity of 2.5×10^5 e^＋/s and the beam profile whose diameter is 10 mm has been obtained; the moderation efficiency of the tungsten mesh moderator reaches 5.1×10^-4 as calculated with an original positron source activity of 52 mCi.
基金Supported by National Natural Science Foundation of China(11075195)Science & Technology Innovation Talents in Universities of Henan Province(13HASTIT046)Young Teacher Project in Henan Normal University
文摘The neutron induced reactions on ^23Na are investigated by using the Talys1.4 program. The calculated results for the ^23Na（n, 2n）22Na reaction are found to agree with the experimental results. The cross sections of the residues of the（n, n）,（n, γ）,（n, p）, and（n, np） channels in the reactions are presented, and at the same time, the neutron induced reactions on22 Ne are also investigated.
文摘In recent years the experiments of CERN-UA5 and NA22 Collaboration find that rapidity η-multiplicity N correlation is a visual scaling (s<sup>1/2</sup>=22—900 G-eV) and η<sub>cut</sub><sup>-</sup>N correlations are very complicated. These correlations may be helpful for building multihadron dynamics. We shall compare these data with the theory of quantum field at short
