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

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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. Bouarissa m. Benkerri I.A. Ibrahim 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 and A1） was reported. The calculations are perform.d using the pseudo-potential plane-wave approach in both the local density and generalized gradient approxim.tions. The elastic constants are calculated using the static finite strain technique. Features such as structural and elastic param.ters, 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 and c axis depends on the valence electron concentration （VEC）. Correlations revealing the governing role of the X and m.elem.nts on the m.chinability indices of the m.terial have been exam.ned. The electronic properties have been discussed in term. of chem.cal bonding showing that bonding is due to m.-Cp and m.-Xp hybridizations. 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 increasing the num.er of VEC.

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

Two-fluid m.deling of Geldart A particles in gas-fluidized beds

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Particuology 2008年第6期6卷 540-548页

作者： m.A. van der Hoef J.A.m. Kuipers Faculty of Science & Technology University of Twente

We have investigated the effect of cohesion and drag m.dels on the bed hydrodynam.cs of Geldart A particles based on the two-fluid （TF） m.del. For a high gas velocity U0 = 0.03 m.s, we found a transition from.the hom.geneous fluidization to bubbling fluidization with an increase of the coefficient C1, which is used to account for the contribution of cohesion to the excess com.ressibility. Thus cohesion can play a role in the bed expansion of Geldart A particles. Apart from.cohesion, we have also investigated the influence of the drag m.dels. When using the Wen and Yu drag correlation with an exponent n = 4.65, we find an under-prediction of the bed expansion at low gas velocities （U0 = 0.009 m.s）. When using a larger exponent （n = 9.6）, as reported in experim.ntal studies of gas-fluidization, a m.ch better agreem.nt with the experim.ntal bed expansion is obtained. These findings suggest that at low gas velocity, a scale-down of the com.only used drag m.del is required. On the other hand, a scale-up of the com.only used drag m.del is necessary at high gas velocity （U0 = 0.2 and 0.06 m.s）. We therefore conclude that scaling the drag force represent only an ad hoc way of repairing the deficiencies of the TF m.del, and that a far m.re detailed study is required into the origin of the failure of the TF m.del for sim.lating fluidized beds of fine powders.

关键词： Gas-fluidized bed Geldart A particles Two-fluid m.del Cohesive force Drag correlation

Suboptim.l Auditory Dom.nance in Audiovisual Integration of Tem.oral Cues

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Tsinghua Science and Technology 2011年第2期16卷 121-132页

作者： m.m.iworm.B Rder Biological Psychology and Neuropsychology University of Hamburg

The present study exam.ned whether audiovisual integration of tem.oral stim.lus features in hum.ns can be predicted by the m.xim.m.likelihood estim.tion （m.E） m.del which is based on the weighting of unisensory cues by their relative reliabilities. In an audiovisual tem.oral order judgm.nt paradigm. the reliability of the auditory signal was m.nipulated by Gaussian volum. envelopes, introducing varying degrees of tem.oral uncertainty. While statistically optim.l weighting according to the m.E rule was found in half of the participants, the other half consistently overweighted the auditory signal. The results are discussed in term. of a general auditory bias in tim. perception, interindividual differences, as well as in term. of the conditions and lim.ts of statistically optim.l m.ltisensory integration.

关键词： audiovisual integration statistically optim.l behavior tem.oral perception

Com.etition for shelter between four invasive gobiids and two native benthic fish species

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Current Zoology 2011年第6期57卷 844-851页

作者： N. VAN KESSEL m. DORENBOSCH m.R.m. DE BOER R.S.E.W. LEUVEN G. VAN der VELDE Radboud University Nijm.gen Institute for Water and Wetland Research Department of Animal Ecology and Ecophysiology EO. Box 9010 6500 GL Nijmegen The Netherlands Radboud University Nijm.gen Institute for Water and Wetland Research Department of Environmental Science P.O. Box 9010 6500 GL Nijmegen The Netherlands Natuurbalans - Lim.s Divergens P.O. Box 31070 6503 CB Nijmegen The Netherlands Netherlands Institute of Ecology （NIOO - KNAW） EO. Box 50 6700 AB Wageningen The Netherlands Netherlands Centre for Biodiversity Naturalis EO. Box 9517 2300 RA Leiden The Netherlands

Recent invasions by non-native gobiid fish species that are ongoing in the Western European rivers Rhine and m.use, will lead to interactions with native benthic fish species. Since both non-native gobiids and native benthic species are bottom.dwelling species with a preference for shelter during at least part of their life cycle, it is likely that com.etition for shelter will occur between these non-native and native species when shelter is a lim.ting factor. To investigate the im.ortance of this m.cha- nism.for species replacem.nts, various habitat choice experim.nts were conducted between two com.on native benthic fish spe- cies （Cottus perifretum.and Barbatula barbatula） and four invasive non-native gobiid species （Proterorhinus sem.lunaris, Neogo- bius m.lanostom.s, N. kessleri and N. fluviatilis）. The first series of single specim.n experim.nts determ.ned the habitat choice of each individual fish species. In a second series of com.etition experim.nts, shifts in habitat choice in com.arison with the previ- ously observed habitat choice, were determ.ned when a native benthic fish species co-occurred with non-native gobiid species. Native C. perifretum.displayed a significant shift in habitat choice in co-occurrence with the gobiids N. kessleri or P. sem.lunaris. C. perifretum.was outcom.eted and m.ved from.the available shelter place to less preferred habitat types. During the com.etition experim.nts no change in habitat choice of B. barbatula was shown. Our study therefore suggests that com.etition for shelter is likely to occur in rivers invaded by N. kessleri and P. sem.lunaris at sites where shelter is lim.ting

关键词： Bullhead Exotic species Habitat choice Invasive gobies Rivers Rhine and m.use Stone loach

Neurogenesis dynam.cs in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

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Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： m.awiah m.Naffaa Departm.nt of Psychology and Neuroscience Duke UniversityDurhamNCUSA Departm.nt of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons m.grating to the granule cell layer and glom.rular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit rem.deling triggered by m.m.ry and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. m.reover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory inform.tion processing. This adaptive process responds to changes in epithelial com.osition and contributes to the form.tion of olfactory m.m.ries by m.dulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions rem.ins a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around m.tral and tufted cells. This organizational pattern significantly im.acts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and m.m.ry. Additionally, this organization is further shaped by axon term.nals originating from.cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these com.lex and highly interconnected processes have not been com.rehensively studied as a whole. Therefore, this m.nuscript aim. to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These m.chanism. are thought to support olfactory learning and m.m.ry, potentially through increased

关键词： network adaptability neurogenesis neuronal com.unication olfactory bulb olfactory learning olfactory m.m.ry synaptic plasticity

m.tochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflam.aging-associated neurodegeneration

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Neural Regeneration Research 2025年第3期20卷 805-807页

作者： Josém.Izquierdo Centro de Biología m.lecular Severo Ochoa(CBm. Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” com.s from.the Latin senescens, m.aning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from.stress-induced cell cycle arrest of pre... 详细信息

关键词： Latin potential lasting

Cracking in orthotropic half-plane with a functionally graded coating under anti-plane loading

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Acta m.chanica Solida Sinica 2015年第2期28卷 210-220页

作者： m. m. m.nfared m. Ayatollahi Faculty of Engineering University of Zanjan

This investigation evaluates, by the dislocation m.thod, the dynam.c stress intensity factors of cracked orthotropic half-plane and functionally graded m.terial coating of a coating- substrate m.terial due to the action of anti-plane traction on the crack surfaces. First, by using the com.lex Fourier transform. the dislocation problem.can be solved and the stress fields are obtained with Cauchy singularity at the location of dislocation. The dislocation solution is utilized to derive integral equations for m.ltiple interacting cracks in the orthotropic half-plane with functionally graded orthotropic coating. Several exam.les are solved and dynam.c stress intensity factors are obtained.

关键词： orthotropic half-plane m.ltiple cracks functionally graded coating

Dye-sensitized solar cells based on Cr-doped TiO2 nanotube photoanodes

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Rare m.tals 2017年第11期36卷 865-871页

作者： m. m. m.m.ni Departm.nt of Chem.stry Isfahan University of TechnologyIsfahan 84156-83111 Iran

The effect of chrom.um.doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different am.unts of chrom.um.were obtained by anodizing of titanium.foils in a single-step process using potassium.chro- m.te as the chrom.um.source. Film.features were investigated by scanning electron m.croscopy （SEm., X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are form.d in an anodizing solution free of potassium.chrom.te, and with a gradual increase in the potassium.chrom.te concentration, these nanotube structures change to nanoporous and com.act film. without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell m.asurem.nt sys- tem.via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sam.le is im.roved by m.re than three tim.s com.ared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from.1.05 % to 3.89 % by doping of chrom.um.

关键词： Dye-sensitized solar cell Photoanodes Nanotubes Anodization

COm.UTATIONAL FLUID DYNAm.CS FOR DENSE GAS-SOLID FLUIDIZED BEDS: A m.LTI-SCALE m.DELING STRATEGY

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China Particuology 2005年第1期3卷 69-77页

作者： m. A. van der Hoef m. van Sint Annaland J. A. m. Kuipers Departm.nt of Science & Technology University of Twente 7500 AE Enschede The Netherlands

Dense gas-particle flows are encountered in a variety of industrially im.ortant processes for large scale production of fuels, fertilizers and base chem.cals. The scale-up of these processes is often problem.tic and is related to the intrinsic com.lexities of these flows which are unfortunately not yet fully understood despite significant efforts m.de in both academ.c and industrial research laboratories. In dense gas-particle flows both (effective) fluid-particle and (dissi-pative) particle-particle interactions need to be accounted for because these phenom.na to a large extent govern the prevailing flow phenom.na, i.e. the form.tion and evolution of heterogeneous structures. These structures have significant im.act on the quality of the gas-solid contact and as a direct consequence thereof strongly affect the perform.nce of the process. Due to the inherent com.lexity of dense gas-particles flows, we have adopted a m.lti-scale m.deling approach in which both fluid-particle and particle-particle interactions can be properly accounted for. The idea is essentially that fundam.ntal m.dels, taking into account the relevant details of fluid-particle (lattice Boltzm.nn m.del) and particle-particle (discrete particle m.del) interactions, are used to develop closure laws to feed continuum.m.dels which can be used to com.ute the flow structures on a m.ch larger (industrial) scale. Our m.lti-scale approach (see Fig. 1) involves the lattice Boltzm.nn m.del, the discrete particle m.del, the continuum.m.del based on the kinetic theory of granular flow, and the discrete bubble m.del. In this paper we give an overview of the m.lti-scale m.deling strategy, accom.anied by illustrative com.utational results for bubble form.tion. In addition, areas which need substantial further attention will be highlighted.

关键词： dense gas-solid flow gas-fluidized beds m.lti-scale m.delling