China is rich in resources of rare earths(REs). Based on tremendous work, China has made great achievements in research and development of REs since 1980s, and the production of RE has won the leading position in the ...China is rich in resources of rare earths(REs). Based on tremendous work, China has made great achievements in research and development of REs since 1980s, and the production of RE has won the leading position in the world. The application of RE elements in advanced materials have progressed significantly during the past years. The wide range of rare earth application in China has been reviewed and discussed in this paper, including the development of advanced RE materials (RE-Al alloys, rare earth nonferrous metal alloys, rare earth luminescent materials, rare earth hydrogen storage materials, rare earth permanent magnet and rare earth compounds used in agriculture, i.e., rare earth micronutrient fertilizer etc.) End the research of new RE materials (high T-c rare earth superconductor, rare earth electronic and photonic materials, rare earth ceramics and rare earth precious metal alloys). Finally, the further development works to be required are as follow: (1) to enhance the applied fundamental research, study the intrinsic properties of rare earth elements and develop less well known uses; (2) to undertake the applied research of median and heavy rare earth and find a way out of the unbalance of RE resources in the various applications; (3) to strengthen the applied research of RE element's in energy field, solving the energy-related, energy-saved and environmental problems.展开更多
Experimental electron momentum density of γ-Ce was measured at an intermediate resolution （0.38 a.u.） using 20 Ci 137Cs Compton spectrometer. The experiment was compared with the first ever theoretical Compton prof...Experimental electron momentum density of γ-Ce was measured at an intermediate resolution （0.38 a.u.） using 20 Ci 137Cs Compton spectrometer. The experiment was compared with the first ever theoretical Compton profiles computed using spin polarized relativistic Korringa-Kohn-Rostoker （SPR-KKR） method within atomic sphere approximation; and linear combination of atomic orbitals （LCAO） within generalised gradient approximation （GGA） and recently developed second order generalised gradient approximation （SOGGA）. It was seen that the Compton profile derived from LCAO with GGA and SOGGA schemes gave a reasonable agreement with the experimental Compton line shape. Theoretical anisotropies in Compton profiles derived along [100], [110] and [111] directions were explained in terms of degenerate states in the energy bands.展开更多
文摘China is rich in resources of rare earths(REs). Based on tremendous work, China has made great achievements in research and development of REs since 1980s, and the production of RE has won the leading position in the world. The application of RE elements in advanced materials have progressed significantly during the past years. The wide range of rare earth application in China has been reviewed and discussed in this paper, including the development of advanced RE materials (RE-Al alloys, rare earth nonferrous metal alloys, rare earth luminescent materials, rare earth hydrogen storage materials, rare earth permanent magnet and rare earth compounds used in agriculture, i.e., rare earth micronutrient fertilizer etc.) End the research of new RE materials (high T-c rare earth superconductor, rare earth electronic and photonic materials, rare earth ceramics and rare earth precious metal alloys). Finally, the further development works to be required are as follow: (1) to enhance the applied fundamental research, study the intrinsic properties of rare earth elements and develop less well known uses; (2) to undertake the applied research of median and heavy rare earth and find a way out of the unbalance of RE resources in the various applications; (3) to strengthen the applied research of RE element's in energy field, solving the energy-related, energy-saved and environmental problems.
基金Project supported by CSIR, New Delhi (03(1157)/10/EMR-II)
文摘Experimental electron momentum density of γ-Ce was measured at an intermediate resolution （0.38 a.u.） using 20 Ci 137Cs Compton spectrometer. The experiment was compared with the first ever theoretical Compton profiles computed using spin polarized relativistic Korringa-Kohn-Rostoker （SPR-KKR） method within atomic sphere approximation; and linear combination of atomic orbitals （LCAO） within generalised gradient approximation （GGA） and recently developed second order generalised gradient approximation （SOGGA）. It was seen that the Compton profile derived from LCAO with GGA and SOGGA schemes gave a reasonable agreement with the experimental Compton line shape. Theoretical anisotropies in Compton profiles derived along [100], [110] and [111] directions were explained in terms of degenerate states in the energy bands.
