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first-principle studies of radioactive fission productions Cs/Sr/Ag/I adsorption on chrome-molybdenum steel in Chinese 200 MW HTR-PM

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Nuclear Science and Techniques 2017年第6期28卷 123-132页

作者： Chuan Li Chao Fang Chen Yang Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua University

Chrome-molybdenum steel(2·1/4Cr1Mo) is one of the main products of steam *** adsorption behaviors of radioactive fission products on2·1/4Cr1Mo surface are critical in the analysis of ***,the adsorption behavior of cesium,strontium,silver and iodine on 2·1/4Cr1Mo was investigated with first-principle calculations that the Ag and I atoms prefer to be adsorbed at the square hollow site of the face-centered cubic iron cell with a binding energy of about 1 and 3 eV,*** contrast,Cs and Sr atoms are not adsorbed on the surface of the 2·1/*** results are again confirmed via analysis of charge density differences and the densities of ***,the adsorption rates of these fission products show that only I and Ag have significant adsorption on the metal *** adsorption results explain the amount of adsorbed radionuclides for an evaluation of nuclear safety in *** micro-pictures of the interaction between fission products and materials are a new and useful way to analyze the source term.

关键词： first-principle calculation Fission product Adsorption behavior HTR-PM

first-principle Calculations of Hardness and Melting Point of Mo_2C

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Journal of Materials Science & Technology 2009年第3期25卷 419-422页

作者： X.R. Wang M.F. Yan H.T. Chen School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

This paper has constructed two kinds of atomic and electronic models for hexagonal β-Mo2C and orthorhombic α-Mo2C. The optimized lattice parameters, elastic constant matrixes and overlap population for Mo2C crystal cells have been obtained to realize the characterization of the hardness and melting point of the two structures by the first-principles plane wave pseudo potential method based on the density functional theory. The results reveal that the calculated lattice parameters of the Mo2C crystal cells agree with the experimental and other calculated data. The calculated melting point/hardness are 2715 K/11.38 GPa for β-Mo2C and 2699 K/10.57-12.67 GPa for α-Mo2C, respectively. The calculated results from the density of states （DOS） demonstrate that the hybridization effect between Mo-3d and C-2p states in α-Mo2C crystal cell is much stronger than that in β-Mo2C one.

关键词： first-principle Mo2C Hardness Melting point Density of states

first-principle calculations of interaction of O_2 with pyrite, marcasite and pyrrhotite surfaces

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Transactions of Nonferrous Metals Society of China 2016年第2期26卷 519-526页

作者：赵翠华陈建华李玉琼陈晔李伟洲广西大学材料科学与工程学院南宁530004 广西大学广西高校矿物工程重点实验室南宁530004

The interaction of O2 with pyrite, marcasite and pyrrhotite surfaces was studied using first-principle calculations to obtain the oxidization mechanisms of these minerals. The results show that the adsorption energy of O2 on pyrrhotite surface is the largest, followed by that on marcasite surface and then pyrite surface. O2 molecules adsorbed on pyrite, marcasite and pyrrhotite surfaces are all dissociated. The oxygen atoms and surface atoms of pyrite, marcasite and pyrrhotite surfaces have different bonding structures. Due to more atoms on pyrrhotite and marcasite surfaces interaction with oxygen atoms, the adsorption energies of O2 on pyrrhotite and marcasite surfaces are larger than that on pyrite surface. Larger values of Mulliken populations for O？Fe bond of pyrrhotite surface result in relative larger adsorption energy compared with that on marcasite surface.

关键词： iron sulfide O2 adsorption surface oxidation first-principle

first-principle study of electronic structure and optical properties of Au-doped VO2

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Journal of Central South University 2017年第2期24卷 270-275页

作者：黄德伟赵翠华陈建华李玉琼李伟洲 College of Materials Science and Engineering Guangxi University Nanning 530004 China Guangxi Colleges and University Key Laboratory of Minerals Engineering Guangxi University Nanning 530004 China

The electronic structure and optical properties of VO2 and Au-VO2 were studied using density functional theory. The calculation results show that the interaction between Au and O is stronger than that between V and O. There exists not only the covalent bonding but also ionic bonding in Au--O bond. The band gap of Au-VO2 is smaller than that of VO〉 while the dielectric constant, conductivity, and intensity of optical absorption of Au-VO2 are larger than those of VO2.

关键词： Au-VO2 electronic structure optical property first-principle

first-principle study on phase Al_(0.8)Ni_3Sn_(0.2) in Sn-Ni-Al alloy as anode for lithium ion battery

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Chinese Physics B 2010年第11期19卷 521-527页

作者：黄钊文胡社军侯贤华赵灵智汝强李伟善张志文 School of Physics and Telecommunication Engineering South China Normal University Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes South China Normal University

The mechanism of lithium intercalation/deintercalation for phase Al0.8Ni3Sn0.2 as anode material used in lithium ion battery was studied carefully based on the first-principle plane wave pseudo-potential method. The calculated results indicated that SnNi Al alloy had high theoretical capacity when used as anode material, however, there was high initial irreversible capacity loss because of the large volume expansion. Therefore the technological parameters during preparing the Sn-Ni-Al anode should be controlled strictly to make the content of Al0.8Ni3Sn0.2 phase as low as possible and to make the anode consist of promising Sn-Ni and AI-Ni phases. For comparison, an experiment based on magnetron sputtering was done. The result showed that the calculation is in good agreement with the experiment. We found that the first-principle investigation method is of far-reaching significance in synthesising new commercial anode materials with high capacity and good cycle performance.

关键词： Sn-Ni-Al alloy first-principle lithium ion battery

first-principle study on anatase TiO_2 codoped with nitrogen and ytterbium

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Journal of Semiconductors 2010年第3期31卷 1-6页

作者：高攀张学军周文芳吴晶柳清菊 Yunnan Key Laboratory of Nanomaterials & Technology Yunnan University Department of Physics and Electric Information Engineering Hunan City University

Crystal structures, electronic structures and optical properties of nitrogen and ytterbium doping anatase TiO2 were calculated by first principles with the plane-wave ultrasoft psendopotential method based on the density functional theory. The calculated results show that the octahedral dipole moments in TiO2 increase due to the changes in lattice parameters, bond length and charges on atoms, which is very effective for the separation ofphotoexcited electron-hole pairs and the improvement of the photocatalytic activity ofTiO2. The interband transition between OPπ states and Yb4f states make nitrogen and ytterbium doped TiO2 manifest greater absorption coefficients in the visible-light region.

关键词： YiO2 N+Yb-doped first-principle

first-principle Calculations of V/Fe Doped Anatase TiO_2

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Chinese Journal of Aeronautics 2006年第B12期19卷 162-166页

作者： CAO Hong-hong CHEN Qiang WANG Tian-min School of Science Beijing University of Aeronautics and Astronautics Beijing 100083 China

The electronic structures of the titanium dioxide（TiO2） doped with V and Fe were analyzed by using first-principle calculations based on the density functional theory（DFT） with the full potential linearized augmented plane wave method （FP-LAPW）. The fully optimized structure and the relaxation introduced by impurity were obtained by minimizing the total energy and atomic forces. The unit cell of the V-doped anatase TiO2 is smaller than that of the non-doped one, but for the Fe-doped one, the case is just the opposite. It is found that the apical Ti-O and impurity-O bond lengths of the V/Fe-doped anatase TiO2 are greater than those of the non-doped structure, but smaller for the equatorial bond length. Through the band structures and the density of states, the V-doped TiO2 is shown to be a kind of half-metal, while the Fe-doped TiO2 a kind of metal. The magnetic moments of the V/Fe-doped system are mainly generated by the dopants. The results may be helpful for us to understand the experimental outcome of this system.

关键词： first-principle FP-LAPW DMS anatase electronic properties

first-principle investigation on electronic structures and elastic properties of Al-doped MoSi_2

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Journal of Central South University 2010年第5期17卷 888-894页

作者：刘小良任意徐慧赵中伟 School of Metallurgical Science and Engineering Central South University School of Physical Science and Technology Central South University

The electronic structures and elastic properties of Al-doped MoSi2 were calculated using the plane wave pseudo-potential method based on the density functional theory,in which the generalized-gradient approximation(GGA) was used to describe the exchange-correlation *** from the elastic constants,bulk modulus,shear modulus,elastic modulus and Poisson ratio of Al-doped MoSi2 were obtained by using the Hill *** results indicate that conductivity of Al-doped MoSi2 is improved to some extent in comparison with that of pure MoSi2 due to the orbit hybridization of Mo 4d,Al 3p and Si 3p *** addition,calculations show that the elastic modulus and the brittleness of Al-doped MoSi2 are smaller than those of pure MoSi2,which implies that it is feasible to toughen MoSi2 by doping *** agreement of the conclusion with experiment shows that the present theory is reasonable.

关键词： MoSi2 Al-doping electronic structures elastic properties first-principle

MOLECULAR DYNAMICS SIMULATION OF INTERFACIAL DEFECTS WITH MODIFIED POTENTIAL BASED ON THE first-principle

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Acta Mechanica Solida Sinica 2010年第5期23卷 400-406页

作者： Dongwei Ren Jinquan Xu 1(School of Naval Architecture and Civil Engineering,Shanghai Jiaotong University,Shanghai 200240,China) School of Naval Architecture and Civil Engineering Shanghai Jiaotong University Shanghai China

The interfacial molecular structure of materials with different lattice constants is simulated by using the method of molecular dynamics （MD）. Potential of modified analytical embedded atom method （MAEAM） is used for nominterfacial atoms. To simulate the state of interracial atoms, further modifications are applied to the MAEAM potential based on the first- principle simulation results. It is concluded that a small change of potential may greatly influence the interfacial molecular structure. Void and diffusions can be observed in the simulation results. It is also found that the pre-existed dot defects before bonding can decrease the number of interfacial defects greatly, thereby, can increase the strength of the interface.

关键词： molecular dynamics interface defect potential first-principle