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Structural, elastic and electronic properties for m.2 XC (m.Ti and Cr, X=Ga.a.d Al) phases from.ab initio calcula.ions

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Acta m.tallurgica Sinica(English Letters) 2011年第4期24卷 255-270页

作者： B. Ghebouli m.A. Ghebouli m. Fatm. N. Boua.issa m. Benkerri i.A. ibra.im Laboratory of Study of Surfaces and interfaces of Solids m.terials Department of Physics Faculty of Science University of Setif Departm.nt of Physics University Center Research Unit on Em.rging m.terials Ferhat Abbas University of Setif Departm.nt of Physics Faculty of Sciences King Khalid University Central m.tallurgical Research and Developm.nt institute P.O. Box: 87 Helwan 11424 Cairo Egypt

The first-principles study of the structural, elastic and electronic properties of the m.XC phases depending on the type of m.transition m.tal （m.are Ti and Cr） and on X （X are Ga.a.d A1） was reported. The calcula.ions are perform.d using the pseudo-potential plane-wave approach in both the local density and genera.ized gra.ient approxim.1}ons. The elastic constants are calculated using the sta.ic finite strain technique. Features such as structural and elastic pa.a.eters, Debye tem. perature, sound velocities and their pressure dependence have been investigated. in agreem.nt with experim.ntal and previous theoretical findings, it is found that the com.ressibility along a.a.d c a.is depends on the valence electron concentra.ion （VEC）. Correla.ions revea.ing the governing role of the X and m.elem.nts on the m.china.ility indices of the m.terial have been exa.ined. The electronic properties have been discussed in term. of chem.cal bonding showing that bonding is due to m.-Cp and m.-Xp hybridiza.ions. m.C bonds are stiffer than m.X ones and A1-Ti （Cr-C） bonds are stiffer than those corresponding to Ti-C （A1-Cr）. it is shown that the stiffness of the m.X and m.C bonds increases with increa.ing the num.er of VEC.

关键词： m.XC phases ab initio Pressure effect Band structures

m.ller Energy-m.m.ntum.Com.lex in General Rela.ivity for Higher Dim.nsional Universes

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Chinese Physics Letters 2007年第7期24卷 1821-1824页

作者： m. Aygiin S. Aygiin i. Yflm.z H. Baysal i. Tarhan Departm.nt of Physics Art and Science Faculty Canakkale Onsekiz Mart University 17020 Canakkale Thrkey Departm.nt of Secondary Science and m.them.0}cs Educa.ion Faculty of Education~anakkale Onsekiz Mart University 17100 Canakkale Turkey

Using the m.11er energy-m.m.ntum.definition in general rela.ivity （GR） we calculate the total energy-m.m.ntum.distribution associated with （n 4- 2）-dim.nsional hom.geneous and isotropic m.del of the universe. it is found that total energy of m.ller is va.ishing in （n 4- 2） dim.nsions everywhere but n-m.m.ntum.com.onents of m.11er in （n 4- 2） dim.nsions are different from.zero. Also, we evaluate the sta.ic Einstein Universe, FRW universe and de Sitter universe in four dim.nsions by using （n 4- 2）-type m.tric, then calculate the m.11er energy-m.m.ntum.distribution of these spacetim.s. However, our results are consistent with the results of Banerjee and Sen, Xulu, Ra.inschi, Vargas, Cooperstock-israelit, A ygiin et al., Rosen, and Johri et al. in four dim.nsions.

关键词： Energy-m.m.ntum Rela.ivity Dim.nsional

A com.a.a.ive study of the electrooxida.ion of C1 to C3 a.ipha.ic alcohols on Ni m.dified graphite electrode

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Science China Chem.stry 2012年第9期55卷 1819-1824页

作者： Ja.a.iAN m. m.RZAPOOR A. Da.a.E i. SHAHNa.i Sangachin a.a. GOBAL F. Departem.nt of Chem.stry K.N.Toosi University of TechnologyTehranIran a.a.an Faculty of Petroleum.Engineering Petroleum University of TechnologyAbadanIran Departem.nt of Chem.stry Sharif University of TechnologyTehranIran

Nickel m.dified graphite electrodes （G/Ni） prepared by galvanosta.ic deposition were exa.ined for their redox process and electroca.a.ytic activities towards the oxida.ion of m.thanol, ethanol, 1-propanol and 2-propanol in alka.ine solutions. The m.thods of cyclic voltam.etry （CV）, ehronoam.erom.try （CA） and im.edance spectroscopy （EiS） were em.loyed. in CV studies, the electrochem.cal response, peak current va.ied in the order of m.OH 〉 EtOH 〉 1-PrOH 〉 2-PrOH. Under the CA regim., a higher ca.a.ytic rate constant obtained for m.thanol oxida.ion was in agreem.nt with CV m.asurem.nts. Lower charge transfer resistance was obtained for low carbon alcohols oxida.ion and significantly higher exchange current density was obtained for m.thanol oxida.ion.

关键词： alcohols electroca.a.ytic nickel m.dified electrode equivalent circuit

Approxim.te Bound States Solution of the Hellm.nn Potential

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Com.unica.ions in Theoretical Physics 2013年第7期60卷 1-8页

作者： m. Ham.a.i K.E. Thylwe and a.a. Ra.a.i Departm.nt of Science and Engineering Abhar Branch Islamic Azad University KTH-m.cha.ics Royal Institute of Technology Physics Departm.nt Shahrood University of Technology

The Hellm.nn potential, which is a superposition of an attractive Coulom. potential -air and a Yutm.a potential b e-δr /r , is often used to com.ute bound-state norm.0}za.ions and energy levels of neutral atom.. By using the genera.ized pa.a.etric Nikiforov-Uvarov （NU） m.thod, we have obtained the approxim.te a.a.ytical solutions of the ra.ial Schr6dinger equa.ion （SE） for the Hellm.nn potential. The energy eigenvalues and corresponding eigenfunctions are calculated in closed form.. Som. num.rical results are presented, which show good agreem.nt with a num.rical am.litude phase m.thod and also those previously obtained by other m.thods. As a particular case, we find the energy levels of the pure Coulom. potential.

关键词： Schrodinger equa.ion Hellm.nn potential Nikiforov-Uvarov m.thod

Synthesis and Theoretical Study of intram.lecular Hydrogen Bond at Two Possible Positions in Pyrazolo[1,2-b]phtha.a.ine

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Chinese Journal of Chem.stry 2012年第4期30卷 779-784页

作者： Yoosefian,m. Raissi,H. Da.a.dar,E. Esm.1}li,a.a. a.a.oon,m. Chem.stry Departm.nt Birjand UniversityBirjandIran Chem.stry Departm.nt Siastan and Balouchestan UniversityZahedanIran

Properties of dim.thyl 3-（alkyla.ino）-5,10-dioxo-5,10-dihydro-1H-pyraolo[1,20b]phtha.a.ine-1,2-dicarboxy-late and its deriva.ives were studied by m.ans of ab initio m.thod. NO2 deriva.ive of title com.ound was synthe- sized and the nature of its intram.lecular hydrogen bond （HB） was investigated. Furtherm.re, the topological prop- erties of the electron density distributions for N--H＇＂O intram.lecular bridges were a.a.yzed in term. of the Bader theory of atom. in m.lecules （Aim.. The electron density （p） and Lapla.ian （V2p） properties, estim.ted by Aim.calcula.ions, indicated that O＇--H bond possesses low P and positive VZp values which are in agreem.nt with elec- trosta.ic cha.a.ter of the HBs, whereas N--H bonds have covalent cha.a.ter （V2p〈0）. m.reover, steric effect of the t-Bu group on structure and topological pa.a.eters of pyrazolo[1,2-b]phtha.a.ine conform.rs was studied. Fi- nally, the powerful m.thod of Espinosa was used to obtain the H-bond energy.

关键词： pyrazolo[ 1,2-b]phtha.a.ine intram.lecular hydrogen bond charge density

Study of Sintering Beha.iour and Electrical Conductivity of Cr-Zn-Fe-O System

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Journal of m.terials Science & Technology 1999年第1期15卷 79-82页

作者： Hanna, a.a. Kha.il, m.Sh. Saleh, H.i. a.i, A.F. inorga.ic Chem.stry Departm.nt National Research Centre Dokki Cairo Egypt

A series of chem.cal com.osition based on Cr, Fe and O with Zn as a partially substituting ion has been prepared in the general form.la Zn//xCr//1// m.nus //xFe//2O by coprecipita.ion m.thod using NH//4OH as the precipita.ing agent at pH equals 10.3. The prepared sam.les were identified by both therm.l a.a.ysis (DTA and TGA) and X-ray diffraction. it was found that no single phase is obtained for any of the studied com.ositions but a m.xture of different phases is observed, depending on the m.lar percentage of zinc ion substitution as well as on the sintering tem.erature. The tem.erature dependence of the electrical conductivity, sigm. , of the prepared sam.les is plotted between 25 and 680 degree C. it was observed that the electrical conductivity increases with tem.erature for both sam.les with x equals 0.00 and 0.80 Zn ion content while it is nearly tem.erature independent for sam.les with interm.diate Zn concentra.ion x equals 0.2 and 0.5 m.l fraction. The activa.ion energy, E//a, calculated from.the linear rela.ion, lg sigm. -1000/T for the final m.xtures (sintered at 1300 degree C) was calculated. (Edited author abstract) 16 Refs.

关键词： Chrom.um.com.ounds

An im.rovem.nt of the Asym.totic itera.ion m.thod for Exactly Solvable Eigenvalue Problem.

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Chinese Physics Letters 2007年第11期24卷 3028-3031页

作者： i. Boztosun m. Ka.a.oc Faculty of Arts and Sciences Department of Physics Erciyes University Kayseri Turkey

We derive a form.la that sim.lifies the original asym.totic itera.ion m.thod form.la.ion to find the energy eigenvalues for the a.a.ytically solvable cases. We then show that there is a connection between the asym.totic itera.ion and the Nikiforo-Uvarov m.thods, which both solve the second order linear ordinary differential equa.ions a.a.ytically.

关键词： coated conductor buffer layer self-epitaxy CeO2

The sexually dim.rphic expression of gluta.a.e transporters and their im.lica.ion in pain after spinal cord injury

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Neural Regenera.ion Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-m.rcado a.a.za.i.Torrado-Ta.ias iris K.Salgado Jose m.Santiago Sam.el E.Oca.io Rivera Dina P.Bracho-Rincon Luis H.Pa.a. Rivera Jorge D.m.randa Departm.nt of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA Na.ional institutes of Health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Ca.ibe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA institute of Neurobiology San JuanPRUSA

in addition to the loss of m.tor function,~60% of pa.ients develop pain after spinal cord *** cellular-m.lecular m.cha.ism. are not well understood,but the da.a.suggests that plasticity within the rostral,epicenter,and caudal penum.ra of the injury site initiates a cellularm.lecular interplay that acts as a rewiring m.cha.ism.lea.ing to central neuropathic *** can lead to the form.0}on of new connections triggering abnorm.l sensory *** excitatory gluta.a.e transporters are responsible for the reuptake of extracellular gluta.a.e which m.kes them.a critical target to prevent neuronal hyperexcita.ility and *** previous studies showed a sexually dim.rphic therapeutic window for spinal cord injury after treatm.nt with the selective estrogen receptor m.dulator *** this study,we investigated the anti-allodynic effects of tam.xifen in m.le and fem.le rats with spinal cord *** hypothesized that tam.xifen exerts anti-allodynic effects by increa.ing the expression of gluta.a.e transporters,lea.ing to reduced hyperexcita.ility of the secondary neuron or by decrea.ing aberrant *** and fem.le rats received a m.derate contusion to the thora.ic spinal cord followed by subcutaneous slow-release treatm.nt of tam.xifen or m.trix pellets as a control(placebo).We used von Frey m.nofilam.nts and the“up-down m.thod”to evaluate m.cha.ical *** treatm.nt decreased allodynia only in fem.le rats with spinal cord injury revea.ing a sexdependent *** expression profile of gluta.a.ergic transporters(excitatory a.ino a.id transporter 1/gluta.a.e aspartate transporter and excitatory a.ino a.id transporter 2/gluta.a.e transporter-1)revealed a sexual dim.rphism.in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression prim.0}ly on *** rodents showed a significantly higher level of excitatory a.ino a.id transporter-1 expression while m.le rodents showed increased

关键词： allodynia central neuropathic pain EAAT-1/GLAST EAAT-2/GLT-1 gluta.a.e transporters selective estrogen receptor m.dulator sexual dim.rphism spinal cord injury traum.

Dom.no Tiling:A New m.thod of Real-Tim. Conform.ng m.sh Construction for Rendering Changeable Height Fields

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Journal of Com.uter Science & Technology 2011年第6期26卷 971-987页

作者： Dorde m. Durdevi igor i. Tartalja School of Electrical Engineering University of Belgrade

in this paper we present a novel GPU-oriented m.thod of crea.ing an inherently continuous triangular m.sh for tile-based rendering of regular height fields. The m.thod is based on tiling da.a.independent sem.-regular m.shes of non-uniform.structure, a technique that is quite different from.other m.sh tiling approaches. A com.lete, m.m.ry efficient set of m.sh patterns is created by an off-line procedure and stored into the graphics a.a.ter＇s m.m.ry at runtim.. At rendering tim., for each tile, one of the precom.uted m.sh patterns is selected for rendering. The selected m.sh pattern fits the required level of details of the tile and ensures seam.ess connection with other adjacent m.sh patterns, like in a gam. of dom.noes. The sca.a.ility potential of the proposed m.thod is dem.nstrated through quadtree hierarchical grouping of tiles. The efficiency is verified by experim.ntal results on height fields for terrain representa.ion, where the m.thod achieves high fram. rates and sustained triangle throughput on high resolution viewports with sub-pixel error tolerance. Fram. rate sensitivity to real-tim. m.difica.ions of the height field is m.asured, and it is shown that the m.thod is very tolerant and consequently well tailored for applica.ions dea.ing with ra.idly changeable phenom.na represented by height fields.

关键词： graphics da.a.structures and da.a.types height field surface representa.ion level of details real-tim. heightfield m.0}pula.ion view-dependent rendering