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Electronic structure of FCC phase in Fe-Mn-Si based shape memory alloys and its stability

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Science China(Technological Sciences) 2001年第5期44卷 486-492页

作者：万见峰陈世朴徐祖耀 School of Matericls Science and Engineering Shanghai Jiatong UniversityShanghai 200030China

The relationship between the electronic structure of FCC phase in Fe?Mn?Si alloy and its stability has been studied by using the discrete variational method based on the first principle. The reason why Mn and Si elements have different influences on the stacking fault energy may be related to the electron concentration (e/a). Si reduces the hole number of 3d band while Mn is rather complicated. The binding energy has been calculated and the experimental results that martensite start temperature (Ms) varies with SI and Mn are explained. When the external stress is exerted in three directions, the electronic structure, the total density of states, the energy gap at Fermi energy level(E F) and the energy degeneracy will change into other states. When the different external stresses are exerted in one direction, 3d or 4s orbital occupations of the central atom decrease, the partial density of states seems to be thinner and its peak increases atE F, the bond orbit shrinks in the direction of the external stress and another bond orbit comes out vertically. These lead to an a decrease in the structural stability and an increase In Ms temperature under the extemal stress.

关键词： Fe-Mn-Si alloy electronic structure structural stability binding energy

Investigation of neutron density distribution of^208Pb nucleus when the proton density is constrained to its experimental distribution

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Chinese Physics C 2020年第8期44卷 132-138页

作者： A.R.Abdulghany Physics Department Faculty of ScienceCairo UniversityGizaEgypt

In this study,two novel improvements for the theoretical calculation of neutron distributions are ***,the available experimental proton distributions are used as a constraint rather than inferred from the ***,the recently proposed distribution formula,d3pF,is used for the neutron density,which is more detailed than the usual shapes,for the first time in a nuclear structure calculation.A semi-microscopic approach for binding energy calculation is considered in this ***,the proposed improvements can be introduced to any other *** ground state binding energy and neutron density distribution of 208Pb nucleus are calculated by optimizing the binding energy considering three different distribution *** implementation of the proposed improvements leads to qualitative and quantitative improvements in the calculation of the binding energy and neutron density *** calculated binding energy agrees with the experimental value,and the calculated neutron density exhibits fluctuations within the nuclear interior,which corresponds with the predictions of self-consistent approaches.

关键词： nuclear density density-fluctuation binding energy

Hyperon Haloes in A Hypernuclei in the Relativistic Continuum Hartree—Bogoliubov Theory

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Chinese Physics Letters 2002年第12期19卷 1775-1778页

作者：吕洪凤孟杰等 SchoolofPhysics PekingUniversityBeijing100871 SchoolofPhysics PekingUniversityBeijing100871 InstituteofThoreticalPhysics ChineseAca

We investigate the existence of a single-Λ hyperon halo in ^153ΛC and a two-Λ hyperon halo in ^164ΛC. Ground-state properties of hyperon carbon isotopes, such as density distributions, single particle levels in the canonical basis, the binding energy, Λ separation energy and radii, are calculated and discussed by using the relativistic continuum Hartree-Bogoliubov theory. The hyperon halo phenomenon in ^153ΛC and ^164ΛC is supported by the discussion of the weakly bound state 1p3/2, extended density distribution and small separation energy of the Λ hyperon.

关键词： Radius haloes Bogoliubov theory density distribution binding energy isopycnal theories

Theoretical Study on Properties of New Isotope 265Bh

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Communications in Theoretical Physics 2006年第4期45卷 681-686页

作者： ZHANG Hong-Fei ZUO Wei LI Jun-Qing Soojae Im MA Zhong-Yu CHEN Bao-Qju Institute of Modern Physics the Chinese Academy of Sciences Lanzhou 730000 China Graduate School of＇the Chinese Academy of Sciences Beijin 100049 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator Lanzhou 730000 China Institut für Theoretische Physik Justus-Liebig-Universitaet Heinrich-Buff-Ring 16 D 35392 Giessen Germany China Institute of Atomic energy Beijing 102413 China

The properties of nuclei belonging to the newly observed α-decay chain starting from ^265Bh have been studied. The axially deformed relativistic mean-field calculation with the force NL-Z2 has been performed in the blocked BCS approximation. Some ground state properties such as binding energies, deformations, spins, and parities, as well as Q-values of the a-decay for this decay chain have been calculated and compared with known experimentai data. Good agreement is found. The slngle-particle spectrum of the nucleus ^265Bh is studied and some new magic numbers are found, while the magnitudes of the shell gaps in superheavy nuclei are much smaller than those of nuclei before the actinium region, and the Fermi surfaces are close to the continuum. Thus the superheavy nuclei are usually not stable. The a-decay lifetimes in the ^265Bh decay chain are evaluated by different formulae, and compared with experimental data. The methods which give good agreement with the data are selected.

关键词： relativistic mean field superheavy nuclei binding energy lifetimes

Structures, Stabilities and Work Functions of Alkali-metal-adsorbed Boron α1-Sheets

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Chemical Research in Chinese Universities 2017年第4期33卷 631-637页

作者： YI Tingting ZHENG Bing YU Haitao XIE Ying Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Materials Science Heilongfiang University Harbin 150080 P. R. China

In this study, we employed the density functional theory method to simulate Li-, Na- and K-adsorbed boron α1-sheets（al-BSTs）. After optimizing possible structures, we investigated their thermodynamic stabilities, barriers for metal atom diffusion on the substrate, and work functions. The computed results indicate that the work function of α1-BST decreases significantly after the adsorption of Li, Na and K. Furthermore, under high hole coverage, these alkali-metal-adsorbed α1-BSTs have lower work functions than the two-dimensional materials of greatest concern and the commonly used electrode materials Ca and Mg. Therefore, the Li-, Na- and K-adsorbed α1-BSTs are potential low-work-function nanomaterials.

关键词： Boron α1-sheet binding energy Migration barrier Alkali metal adsorption, Work function

Ionized Acceptor Bound Exciton States in Wurtzite GaN/Al_xGa(1-x)N Cylindrical Quantum Dot

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Communications in Theoretical Physics 2012年第1期57卷 151-156页

作者：郑冬梅王宗箎 Department of Physics and Electromechanical Engineering Sanming College

Based on the framework of the effective-mass approximation, the ionized acceptor bound exciton （A- X） binding energy and the emission wavelength are investigated for a cylindrical wurtzite （WZ） GaN/A1x Ga1-xN quantum dot （QD） with finite potential barriers by means of a variational method. Numerical results show that the binding energy and the emission wavelength highly depend on the QD size, the position of the ionized acceptor and the Al composition x of the barrier material AIxGal-xN. The binding energy and the emission wavelength are larger when the acceptor is located in the vicinity of the left interface of the QD. In particular, the binding energy of （ A-, X） complex is insensitive to the dot height when the acceptor is located at the left boundary of the QD. The ionized acceptor bound exciton binding energy and the emission wavelength are both increased if Al composition x is increased.

关键词： quantum dot ionized acceptor bound exciton binding energy emission wavelength

Nilsson mean-field plus the extended pairing model description of rare earth nuclei

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Chinese Physics C 2011年第8期35卷 747-752页

作者：关鑫李杭谭奇潘峰 J.P.Draayer Department of Physics Liaoning Normal University Department of Physics and Astronomy Louisiana State University

The Nilsson mean-field plus the extended pairing model for well-deformed nuclei is applied to some representative rare earth examples. The binding energies, some low-lying pair-excited states and evenodd mass differences of Er, Yb and Hf isotopes are calculated systematically within the proton frozen-pair excitation limit. A comparison with experimental data for these nuclei shows that the results of the extended pairing model are better than those for the standard pairing model with the BCS approximation and the nearest-orbit pairing model.

关键词： Nilsson mean-field pairing interaction binding energy even-odd mass difference

Structure of A=11 double-Λ hypernuclei studied with three-body forces

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Chinese Physics C 2013年第5期37卷 22-27页

作者： H. Sadeghi Sh. Nahidinejad K. Bahraminejad Department of Physics Faculty of Science Arak University

The energy levels and AA bond energy of the double-A hypernucleus nBe are calculated considering two- and three-nucleon forces. The interactions between the constituent particles are contact interactions that reproduce the low-energy binding energy of the nuclei. Effective action is constructed to involve the three-body forces. In this paper, we compare the binding energy result that is obtained with the experimental and other modern nucleon- nucleon potentials. The results of all the schemes agree very well, showing the high accuracy of our present ability to calculate the many-nucleon bound state with three-body forces. The experimental value of BAA（Be）=20.83 MeV seems to be more compatible with our calculated value of BAA（Be）=-19.31 MeV in comparison with the calculated result of 18.23 MeV by Hiyama et al.

关键词： five-body cluster A=11 double-A hypernuclei binding energy three-body forces

Speciation evolutions of target metals （Cd, Pb） influenced by chlorine and sulfur during sewage sludge incineration

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Frontiers of Environmental Science & Engineering 2014年第6期8卷 871-876页

作者： Jingde LUAN Rundong LI Zhihui ZHANG Yanlong LI Yun ZHAO Key Laboratory of Clean energy (Liaoning Province) College of Energy and Environment Shenyang Aerospace University Shenyang 110136 China

In sludge incineration, the thermal behavior of heavy metal is a growing concern. In this work, the combined analysis of metal partitioning behavior between vapor phase and condensed phase, speciation redistribu- tion in condensed phase and the difference of metal species in binding energy was carried out to investigate the possible volatilization-condensation mechanism of heavy metals in high-temperature sludge incineration. It was found that there were two steps in metal volatilization. The initial volatilization of heavy metal originated from their exchangeable （EXC）, carbonate bound （CAR） and iron- manganese bound （FM） fractions, which is primarily composed of simple substance, chlorides, oxides and sulfides. With the increase of chlorine and sulfur in sludge, the inner speciation redistribution of heavy metals occurred in condensed phase, which was an important factor affecting the potential volatility of heavy metals. A partial of metal species with complexed （COM） and residual （RES） fractions gradually decomposed into simple substance or ions, oxides and carbonates, which signifi- cantly strengthened the second volatility. In presence of chlorine, about 46% of Cd with the RES fraction disappeared when the volatility rate of Cd increased by 44.89%. Moreover, about 9% of Pb with COM fraction disappeared when there was an increase of nearly 10% in the volatilization rate. Thus, the second volatilization was mainly controlled by the decomposition of metal species with COM and RES fractions. By virtue of XRD analysis and the binding energy calculation, it was found that metal complex and silicates were inclined to decompose under high temperature due to poor thermo stability as compared with sulfates.

关键词： sludge incineration heavy metals inner speciation redistribution binding energy