Guidong granitic complex is constituted by Luxi intrusion, Xiazhuang intrusion, Maofeng intrusion, Sundong intrusion, Aizi intrusion and Siqian intrusion, which emplaced in Indosinian and early Yanshanian Periods. The...Guidong granitic complex is constituted by Luxi intrusion, Xiazhuang intrusion, Maofeng intrusion, Sundong intrusion, Aizi intrusion and Siqian intrusion, which emplaced in Indosinian and early Yanshanian Periods. These intrusions varied from each other not only in major element content, aluminium saturation index, but also in values of ∑REE, δEu, and LREE/HREE, (La/Yb)N, (La/Sm)N and (Gd/Yb)N. The Maofeng intrusion, which has the closest relationship with uranium mineralization, belongs to strong peraluminous granites. Having undergone much intense fluid-rock interaction, it is characterized by typical M-type tetrad effects and lowest values of ∑REE, δEu, LREE/HREE, (La/Yb)N, (La/Sm)N and (Gd/Yb)N ratios than other studied intrusions.展开更多
In this paper, we simulate the exposure factor by a simple model of a flee-air ionization chamber with the Monte Carlo programme Geant4. Special emphasis is placed on the discussion of the exposure factor related to p...In this paper, we simulate the exposure factor by a simple model of a flee-air ionization chamber with the Monte Carlo programme Geant4. Special emphasis is placed on the discussion of the exposure factor related to parameters of the chamber model. The reason for the variation in exposure factor with incident ray energy is also analysed in terms of reaction cross section for different types of reactions. The obtained results indicate that our simulation is accurate in the calculation of the exposure factor and can serve as a reference in designing air ionization chambers.展开更多
The corrosion behavior of ternary Fe-15Cu-5Al(mole fraction,%) alloy was studied at 1 000 ℃ in 0.1 MPa pure oxygen. The Fe-rich alloy shows two parabolic oxidation stages,with a small increase of the parabolic rate c...The corrosion behavior of ternary Fe-15Cu-5Al(mole fraction,%) alloy was studied at 1 000 ℃ in 0.1 MPa pure oxygen. The Fe-rich alloy shows two parabolic oxidation stages,with a small increase of the parabolic rate constant from 1.9×10-9 to 4.1×10-9 g2/(cm4·s). The scale grown on the alloy is very complicated,with formation of overgrown nodules interspersed among bulky stratified scales. The nodules and the bulky stratified scales are always composed of an outer layer of CuFe2O4 and of an inner layer containing Fe2O3 and Fe3O4. Beneath the external scale of the nodules,there is an internal oxidation zone where iron oxide is mixed with copper metal. Furthermore,the base of the internal oxidation zone is characterized by a discontinuous aluminum-enriched layer of either Al2O3 or FeAl2O4. For the stratified scales,no internal oxidation zone is present beneath the innermost Al2O3 or FeAl2O4 layer. Aluminum depletion is present in advance of the internal oxidation front,while iron depletion is not observed. The corrosion feature of the ternary Fe-15Cu-5Al alloy is partly associated with that of the corresponding binary Fe-Cu and Fe-Al alloys. The peculiar scale microstructure observed is considered mainly as a consequence of the limited solubility of the iron and copper components in one another and of the monovariant system of the ternary Fe-15Cu-5Al alloy.展开更多
The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters (core structure, fuel assembly component) by using the Monte Carlo method....The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters (core structure, fuel assembly component) by using the Monte Carlo method. The obtained values of Keff are compared and analysed, which can provide theoretical basis for reactor design.展开更多
Thin silicon phthalocyanine dichloride films on HOPG were prepared and the sample was heated in the vacuum with laser. The thickness of the thin sample on HOPG was checked by X-ray photoemission spectroscopy. The orie...Thin silicon phthalocyanine dichloride films on HOPG were prepared and the sample was heated in the vacuum with laser. The thickness of the thin sample on HOPG was checked by X-ray photoemission spectroscopy. The orientation of the molecules in respect to the substrate plane was investigated by measuring the silicon K-edge near edge X-ray absorption fine structure (NEXAFS). In the NEXAFS spectra of the thin sample, two clear peaks which were assigned to Is → σ^*Si-N and 1s→ σ^*Si-Cl appeared around 1847.2 eV and 1843.1 eV respectively. The intensities of the resonance peaks showed strong polarization dependence. A quantitative analysis of the polarization dependence revealed that the Si-N bond tended to lie down while the Si-Cl bond was out of the molecular plane.展开更多
Recent years have witnessed intense activity concerning the study of nuclei with equal numbers of neutrons and protons (N = Z). Exotic properties have been exhibited in the N = Z nuclei, especially in those with ato...Recent years have witnessed intense activity concerning the study of nuclei with equal numbers of neutrons and protons (N = Z). Exotic properties have been exhibited in the N = Z nuclei, especially in those with atomic masses around 80. In the present paper, the projected shell model(PSM)together with a relativistic Hartree-Bogoliubov (RHB) theory is used to study the nuclear structure near the N = Z line in the mass A ≈ 80 region. For three Zr isotopes 80,82,84Zr, the projected potential energy surfaces and ground state bands are calculated. It is shown that shape coexistence occurs in all of these nuclei. Moreover, we find that the residual neutron-proton interaction strongly affects the ground state band of 80Zr; however, it slightly modifies those of 82Zr and 84Zr.展开更多
High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ...High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ-transition intensities were performed using eight anticompton HPGe detectors and one planar HPGe detector.Based on the measured results,a new level scheme of 84Sr was established in which 12 new states and nearly 30 new γ-transitions were identified in the present work.The positive-parity states of the new level scheme were compared with the results from calculations in the framework of the projected shell model (PSM).One negative-parity band was extended to spin Iπ=19-and it can be found that in the high spin states,the γ-transition energies show the nature of signature staggering.The negative-parity band levels are in good agreement with deformed configuration-mixing shell model (DCM) calculations.展开更多
基金Project supported bythe National Key Science Foundation of China (40132010)the National Science Foundation of China(40642010 ,40772068)
文摘Guidong granitic complex is constituted by Luxi intrusion, Xiazhuang intrusion, Maofeng intrusion, Sundong intrusion, Aizi intrusion and Siqian intrusion, which emplaced in Indosinian and early Yanshanian Periods. These intrusions varied from each other not only in major element content, aluminium saturation index, but also in values of ∑REE, δEu, and LREE/HREE, (La/Yb)N, (La/Sm)N and (Gd/Yb)N. The Maofeng intrusion, which has the closest relationship with uranium mineralization, belongs to strong peraluminous granites. Having undergone much intense fluid-rock interaction, it is characterized by typical M-type tetrad effects and lowest values of ∑REE, δEu, LREE/HREE, (La/Yb)N, (La/Sm)N and (Gd/Yb)N ratios than other studied intrusions.
基金Project supported by the National Natural Science Foundation of China (Grant No 10647109)the Foundation for Key Programof Ministry of Education,China (Grant No 208067)
文摘In this paper, we simulate the exposure factor by a simple model of a flee-air ionization chamber with the Monte Carlo programme Geant4. Special emphasis is placed on the discussion of the exposure factor related to parameters of the chamber model. The reason for the variation in exposure factor with incident ray energy is also analysed in terms of reaction cross section for different types of reactions. The obtained results indicate that our simulation is accurate in the calculation of the exposure factor and can serve as a reference in designing air ionization chambers.
基金Project (05111) supported by the Open Project Program of Key Laboratory of Nuclear Resources and Environment (East China Institute of Technology), Ministry of Education, ChinaProject ([2005]224) supported by the Science and Technology Research Item of Jiangxi Provincial Department of Science and Technology, China
文摘The corrosion behavior of ternary Fe-15Cu-5Al(mole fraction,%) alloy was studied at 1 000 ℃ in 0.1 MPa pure oxygen. The Fe-rich alloy shows two parabolic oxidation stages,with a small increase of the parabolic rate constant from 1.9×10-9 to 4.1×10-9 g2/(cm4·s). The scale grown on the alloy is very complicated,with formation of overgrown nodules interspersed among bulky stratified scales. The nodules and the bulky stratified scales are always composed of an outer layer of CuFe2O4 and of an inner layer containing Fe2O3 and Fe3O4. Beneath the external scale of the nodules,there is an internal oxidation zone where iron oxide is mixed with copper metal. Furthermore,the base of the internal oxidation zone is characterized by a discontinuous aluminum-enriched layer of either Al2O3 or FeAl2O4. For the stratified scales,no internal oxidation zone is present beneath the innermost Al2O3 or FeAl2O4 layer. Aluminum depletion is present in advance of the internal oxidation front,while iron depletion is not observed. The corrosion feature of the ternary Fe-15Cu-5Al alloy is partly associated with that of the corresponding binary Fe-Cu and Fe-Al alloys. The peculiar scale microstructure observed is considered mainly as a consequence of the limited solubility of the iron and copper components in one another and of the monovariant system of the ternary Fe-15Cu-5Al alloy.
基金Project supported by the National Natural Science Foundation of China(Grant No10647109)
文摘The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters (core structure, fuel assembly component) by using the Monte Carlo method. The obtained values of Keff are compared and analysed, which can provide theoretical basis for reactor design.
基金Nuclear Researchers Exchange Program 2005Photon Factory Program Advisory Committee (2004G340)
文摘Thin silicon phthalocyanine dichloride films on HOPG were prepared and the sample was heated in the vacuum with laser. The thickness of the thin sample on HOPG was checked by X-ray photoemission spectroscopy. The orientation of the molecules in respect to the substrate plane was investigated by measuring the silicon K-edge near edge X-ray absorption fine structure (NEXAFS). In the NEXAFS spectra of the thin sample, two clear peaks which were assigned to Is → σ^*Si-N and 1s→ σ^*Si-Cl appeared around 1847.2 eV and 1843.1 eV respectively. The intensities of the resonance peaks showed strong polarization dependence. A quantitative analysis of the polarization dependence revealed that the Si-N bond tended to lie down while the Si-Cl bond was out of the molecular plane.
基金Supported by National Natural Science Foundation of China (10675170)Major State Basic Research Developing Program(2007CB815003)+1 种基金Natural Science Foundation of Jiangxi Province (0612003, 2007GZW0476)Foundation of the Education Department of Jiangxi Province ([2007]235)
文摘Recent years have witnessed intense activity concerning the study of nuclei with equal numbers of neutrons and protons (N = Z). Exotic properties have been exhibited in the N = Z nuclei, especially in those with atomic masses around 80. In the present paper, the projected shell model(PSM)together with a relativistic Hartree-Bogoliubov (RHB) theory is used to study the nuclear structure near the N = Z line in the mass A ≈ 80 region. For three Zr isotopes 80,82,84Zr, the projected potential energy surfaces and ground state bands are calculated. It is shown that shape coexistence occurs in all of these nuclei. Moreover, we find that the residual neutron-proton interaction strongly affects the ground state band of 80Zr; however, it slightly modifies those of 82Zr and 84Zr.
基金supported by the Major State Basic Research Development Program in China (Grant No. 2007CB815003)the National Natural Science Foundation of China (Grant Nos. 11065001, 10547140, 10525520,60476043,10675170,10475002 and 10775064)+4 种基金the U.S. National Science Foundation (Grant No. 0500291)the Southeastern Universities Research Association,the Natural Science Foundation of Jiangxi Province (Grant Nos. 0612003 and 2007GZW0476)the LSU - LNNU Joint Research Program (Grant No. 9961)the Foundation of the Education Department of Jiangxi Province (Grant No. [2007]235)the Liaoning Education Department Fund (Grant No. 20060464)
文摘High spin states of 84Sr were populated through the reaction 70Zn(18O,4n)84Sr at 75 MeV beam energy.Measurement of excitation function,γ-γ coincidences,directional correlation from oriented state (DCO) ratios and γ-transition intensities were performed using eight anticompton HPGe detectors and one planar HPGe detector.Based on the measured results,a new level scheme of 84Sr was established in which 12 new states and nearly 30 new γ-transitions were identified in the present work.The positive-parity states of the new level scheme were compared with the results from calculations in the framework of the projected shell model (PSM).One negative-parity band was extended to spin Iπ=19-and it can be found that in the high spin states,the γ-transition energies show the nature of signature staggering.The negative-parity band levels are in good agreement with deformed configuration-mixing shell model (DCM) calculations.