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Molecular Dynamics, Diffusion Coefficients and Activation energy of the electrolyte (Anode) in Lithium (Li and Li⁺), Sodium (Na and Na⁺) and Potassium (K and K⁺)

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Modeling and Numerical Simulation of Material Science 2024年第1期14卷 39-57页

作者： Alain Second Dzabana Honguelet Timothée Nsongo Bitho Rodongo earvin Loumbandzila Faculty of Science and Technology Marien Ngouabi University Brazzaville Congo Research Group on The Physical and Chemical Properties of Materials Brazzaville Congo Association Alpha Sciences Beta Technologies Brazzaville Congo Centre for Geological and Mining Research Brazzaville Congo

This work is a simulation modelling with the LAMMPS calculation code of an electrode based on alkali metals (lithium, sodium and potassium) using the MeAM potential. For different multiplicities, two models were studied;with and without gap. In this work, we present the structural, physical and chemical properties of the lithium, sodium and potassium electrodes. For the structural properties, the cohesive energy and the mesh parameters were calculated, revealing that, whatever the chemical element selected, the compact hexagonal hcp structure is the most stable, followed by the face-centred cubic CFC structure, and finally the BCC structure. The most stable structure is lithium, with a cohesion energy of -6570 ev, and the lowest bcc-hcp transition energy of -0.553 ev/atom, followed by sodium. For physical properties, kinetic and potential energies were calculated for each of the sectioned chemical elements, with lithium achieving the highest value. Finally, for the chemical properties, we studied the diffusion coefficient and the activation energy. Only potassium followed an opposite order to the other two, with the quantities with lacunae being greater than those without lacunae, whatever the multiplicity. The order of magnitude of the diffusion coefficients is given by the relationship DLi > DNa > Dk for the multiplicity 6*6*6, while for the activation energy the order is reversed.

关键词： Molecular Dynamics Diffusion Coefficients Activation energy Lithium Alkali Metals MeAM Potential

Study of the Physical and Mechanical Properties of Titanium in Volume by the MeAM Method

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Modeling and Numerical Simulation of Material Science 2024年第1期14卷 58-68页

作者： Yahnn J. Mighensle Mimboui Alain S. Dzabana Honguelet Timothée Nsongo Faculty of Science and Technology Marien Ngouabi University Brazzaville Congo Research Group on Physical and Chemical Properties of Materials Brazzaville Congo Association Alpha Sciences Beta Technologies Brazzaville Congo Geological and Mining Research Centre Brazzaville Congo

In this work we present the results of our study on the physical and mechanical properties of titanium in volume. The work consisted in determining its physical and mechanical properties under different crystallographic structures (HCP, FCC, BCC and SC) using the Modified embedded Atom Method (MeAM) and the MeAM potential of titanium. We used the LAMMPS calculation code, based on classical molecular dynamics, to determine the most stable structure of titanium, which is the hexagonal compact structure (HCP) with crystal parameters a = 2.952 Å and c = 4.821 Å and a cohesion energy of -4.87 ev. This structure is seconded by the cubic centred structure (BCC) with a lattice parameter a = 3.274 Å and a cohesive energy of -4.84 ev. It was shown that titanium can crystallise into a third structure which is the face-centred cubic (FCC) structure with a lattice parameter a = 4.143 Å and a cohesive energy of -4.82 ev. The results obtained in this study were compared with the theoretical results and showed considerable agreement.

关键词： MeAM Potential LAMMPS Code Molecular Dynamics elastic Constants Modules Ovito

纳米结构对硬质金属亚表层物理性能的影响(英文)

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稀有金属材料与工程 2015年第1期44卷 1-6页

作者： Ovcharenko V.e. Psaknye S.G. Ivanov Yu.F. Mokhovikov А.А. 于宝海赵彦辉 Ignat’ev A.S. 俄罗斯科学院西伯利亚分院强度物理与材料科学研究所国立托木斯克理工大学俄罗斯科学院西伯利亚分院强流电子研究所中国科学院金属研究所辽宁沈阳110016

介绍了Ti C/Ni-Cr-Al合金陶瓷在脉冲电子束熔化后的实验及结构方面的表征,考察了表面纳米尺寸结构的不同级别对亚表层金属物理性质的影响。结果表明,在氙气或者是氙气+氮气的气体放电等离子体辐照后在亚表层出现纳米结构的碳化物颗粒,... 详细信息

介绍了Ti C/Ni-Cr-Al合金陶瓷在脉冲电子束熔化后的实验及结构方面的表征,考察了表面纳米尺寸结构的不同级别对亚表层金属物理性质的影响。结果表明,在氙气或者是氙气+氮气的气体放电等离子体辐照后在亚表层出现纳米结构的碳化物颗粒,这大大降低了摩擦系数,使金属陶瓷切削金属时的寿命提高约20倍。

关键词：金属陶瓷微观结构结构级别摩擦系数寿命

Role of forests in headwater control with changing environment and society

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International Soil and Water Conservation Research 2021年第1期9卷 143-157页

作者： Josef Krecek Jana Nováková Ladislav Palán eva Pazourková evzen Stuchlík Department of Hydrology Czech Technical University in PragueThákurova 7CZ-16629Prague 6Czech Republic Independent Botanist Na Vrcholu 4CZ-13000PragueCzech Republic AON Impact Forecasting Václavskénáměstí19CZ-11000PragueCzech Republic Institute of Hydrobiology Biology CentreCzech Academy of SciencesNa Sádkách 7CZ-37005(C)eskéBudějoviceCzech Republic

Forest practices in headwater catchments are related to environmental and social *** aim of this study is to analyse the changing protective functions of forests in the upper plain of the Jizera Mts.(North Bohemia,Czech Republic)since the second half of the 19th *** time,forests have gradually changed from native stands to spruce plantations(Picea abies),introducing exotic conifers(more resistant to air pollution),and,recently,back to more diverse mixed *** priority in pro-tective forest functions there shifted from flood protection to integrated control of water resources(quantity and quality).In the 1980s,forest-water interactions were degraded by consequences of extreme acid atmospheric deposition,forest die-back,and extensive *** the Jizerka catchment,first signs of recovery were observed in the early *** waters there are still affected by prolonged *** reconstruction of stream water chemistry at Jizerka follows the drop of the acid deposition in some 5 years,the revival of stream biota takes 10-15 *** 2071-2100,the pro-jected climate change shows rising annual air temperatures by 3.0-4.6℃,decreasing water yield by 65-123 mm,60%drop in'minimum residual discharge',and 20-30%rise in ***,these projected environmental changes cannot substantially decline the high potential in water resource recharge,or,start reverse processes in recent recovery from acidification and radically affect the exis-tence of planned mixed forests in the upper plain of the Jizera Mts.

关键词： Headwater catchment Forest functions Water resource recharge Acid atmospheric deposition Climate change

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洁净煤技术项目融资的可能性综述

能源工程 2003年第5期23卷 38-41页

作者： G Skodras ev Karlopoulos e Kakaras 吴君棋希腊固体燃料技术和应用学院希腊固体燃料技术和应用学院海拉斯研发中心欧盟能源技术促进组织中国〈杭州〉项目组

在不久的将来煤仍然是世界能源生产的主要燃料,煤消耗量的预期增长和对环境保护的日益关注使得洁净煤技术拥有巨大的市场潜力。这一巨大的市场将提供重大的投资机会,吸引众多大型融资机构,同时也将激励公共部门投资示范工程和洁净煤技... 详细信息

在不久的将来煤仍然是世界能源生产的主要燃料,煤消耗量的预期增长和对环境保护的日益关注使得洁净煤技术拥有巨大的市场潜力。这一巨大的市场将提供重大的投资机会,吸引众多大型融资机构,同时也将激励公共部门投资示范工程和洁净煤技术的发展。洁净煤技术的主要融资机构包括世界银行、欧洲投资银行、欧洲改革和发展银行、出口信用代理机构和商业银行。能源服务公司、当地的融资机构、完整的资源规划和需求侧管理将有助于克服融资障碍。

关键词：洁净煤煤炭消耗融资机构融资障碍需求侧管理

Cross section of the Coulomb excitation of ^(229m)Th by low energy muons

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Chinese Physics C 2021年第9期45卷 143-147页

作者： e.V.Tkalya P.N.Lebedev Physical Institute of the Russian Academy of Sciences 11999153 Leninskiy pr.MoscowRussia National Research Nuclear University MePhI 115409Kashirskoe shosse 31MoscowRussia Nuclear Safety Institute of RAS Bofshaya Tulskaya 52Moscow 115191Russia

The inelastic scattering cross section for muons,μ^(-),with energies e=9-100 ev from the ^(229)Th nuclei is calculated in the framework of the second order of the perturbation theory for quantum *** dominant contribution to the excitation of the low energy isomer ^(229m)Th(3/2^(+),8.19±0.12 ev)originates from the e2 *** excitation cross section reaches the value of 10^(-21) cm^(2) in the range e≈10 *** value is four to five orders of magnitude larger than the electron excitation cross section and is sufficient for the efficient excitation of ^(229m)Th on the muon beam at the next generation of muon colliders.

关键词： cross section muon Coulomb excitation Th-229

Structural,morphological and optical properties of new eu-doped and vacancied lead molybdato-tungstates

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Journal of Rare earths 2018年第6期36卷 635-641页

作者： M.Piotkowska e.Tomaszewicz Faculty of Chemical Technology and engineering Department of Inorganic and Analytical ChemistryWest Pomeranian University of TechnologySzczecinAI.Piast6w 4271-065 SzczecinPoland

A new tetragonal,scheelite-type Pb_(1-3 x)■_xeU_(2 x)(MoO_4)_(1-3 x)(WO_4)_(3 x)(0 3 ev) and their band gap nonlinearly decreases with increasing dopant concentration.

A new tetragonal,scheelite-type Pb_(1-3 x)■_xeU_(2 x)(MoO_4)_(1-3 x)(WO_4)_(3 x)(0enotes A-site vacancies) solid solution was synthesized via solid state reaction method. The X-ray diffraction(XRD) and scanning electron microscopy(SeM) results confirm the formation of single, tetragonal scheelite-type phases(space group I4_1/a) with the average crystallite size in the range of ～20-100 μm. Substitution of Pb^(2+) with eu^(3+) is relatively easy despite the large difference in ionic radii, and the formation of vacancies is necessary to compensate the excess positive charge in PbMoO_4 framework. A change in lattice parameters(both a and c as well as lattice parameter ratio c/a) and progressive deformation of MoO_4 and WO_4 tetrahedra with increasing eu concentration are observed. Thermal stability of eu-doped materials strongly depends on the concentration of eu3+ ions. The Pb_(1-3 x)■_xeu_(2 x)(MoO_4)_(1-3 x)(WO_4)_(3 x) solid solution for x=0.0098 shows the highest melting point(1057 ℃) which is slightly higher than that of pure PbMoO_4(1040 ℃). The UV-vis diffuse reflectance spectroscopy(DRS) and the Tauc plots were used to extrapolate the optical indirect band gap(e_g) of doped materials. eu-doped ceramics are insulators(e_g > 3 ev) and their band gap nonlinearly decreases with increasing dopant concentration.

关键词： Molybdato-tungstate Scheelites Thermal stability Optical properties Rare earths

Study of the process e^+e^- →π^+π^-π~0π~0 at energies s～(1/2)<1 Gev

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Chinese Physics C 2010年第6期34卷 680-685页

作者： M.N.Achasov K.I.Beloborodov A.V.Berdyugin A.A.Botov V.B.Golubev T.V.Dimova V.P.Druzhinin L.V.Kardapoltsev A.G.Kharlamov D.P.Kovrizhin I.A.Koop A.A.Korol S.V.Koshuba A.e.Obrazovsky e.V.Pakhtusova D.A.Shtol S.I.Serednyakov Z.K.Silagadze A.N.Skrinsky Yu.A.Tikhonov Yu.M.Shatunov A.V.Vasil'ev Budker Institute of Nuclear Physics Russian Academy of Sciences Novosibirsk State University

In an experiment with the Spherical Neutral Detector at VePP-2M collider the cross section of the process e^＋e^- →π^＋π^-π^0π^0 was measured. At energies √s 〈 920 Mev this cross section was measured for the first time. The energy dependence of the cross section is well discribed by the vector dominance model with contributions from p, p＇, p＂ mesons. The decay probability ρ→π^＋π^-π^0π^0 was found to be Bρ = （1.60±0.74±0.18） × 10^-5. The upper limit for the decay ω→π^＋π^-π^0π^0 was improved by two orders of magnitude compared to the previous measurements and is Bω 〈 2 × 10^-4 at 90% confidence level.

关键词： VePP-2M spherical neutral detector meson decay

Characterization of Magnetron Sputter CN_(x) Thin Films

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Chinese Physics Letters 1998年第2期15卷 120-122页

作者： ZHeNG Wei-tao J.e.Sundgren Department of Materials Science Jilin UniversityChangchun 130023 Department of Physics Linkoping UniversityS-58183 LinkopingSweden

Carbon nitride thin films were deposited at different substrate temperature(ST)by using reactive magnetron sputtering in a pure N_(2) discharge,and studied by laser Raman spectroscopy,x-ray photoelectron spectroscopy(XPS),and spectroscopic *** Raman spectra of the films show that I(D)/I(G)decreased with the increase of *** D bandposition shifted towards lower frequency,while the G bandposition shifted towards higher frequency as the ST *** XPS data exhibit that Nls binding states also depend on *** optical band gap of the films is found dropped from 0.22ev to 0.10ev with the increase of ST.

关键词： shifted films spectroscopic