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Nano Research 2015年第3期8卷 839-850页

作者： Yu-Pu Lin Younal Ksari Jean-Marc Themlin Aix-Marseille UniversitY CNRS Universite de Toulon IM2NP UMR 7334 13397 Marseille France

The hydrogenation at various temperatures of the （6√3 ×6√3）R30° reconstruction of SIC（0001）, the so-called buffer layer graphene （BLG）, is investigated. For the BLG, a significant concentration of remaining dangling bonds related to unsaturated Si atoms of the outermost SiC bilayer is evidenced in the inverse photoemission spectra. These dangling bonds give rise to a peak around 1 eV above the Fermi level, associated with the upper single-electron states of a Mott-Hubbard insulator, which vanishes upon hydrogenation. Hydrogen atoms adsorbed at ambient temperature remain covalently bound to BLG （H-BLG） up to temperatures of -500℃. They induce additional C-Si bonds at the BLG/SiC interface that saturate the remaining Si dangling bonds, as evidenced in both IPES and Auger electron spectra. The H-BLG further shows a large energy gap and an excess n-type doping in comparison to the pristine BLG. Upon hydrogen exposure at higher temperature （〉 700 ℃）, hydrogen atoms intercalate at the BLG/SiC interface, inducing the formation of a single layer of quasi-free- standing graphene （QFSG） lying on top of a hydrogenated （√3×√3）R30° reconstruction as supported by IPES. We suggest that the high-stability and the distinct electronic structure of both BLG-derived structures, H-BLG and QFSG, may open a route for the engineering of graphene-based devices.

关键词： graphene hydrogenation photoemissionspectroscopy electronic structure

On-surface synthesis of covalent coordination polymers on micrometer scale

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Nano Research 2017年第3期10卷 933-940页

作者： Mathieu Koudia Elena Nardi Olivier Siri Mathieu Abel Aix Marseille UniversitY CNRS IM2NP UMR 7334 13397 Marseille France Aix Marseille UniversitY CNRS CINaM UMR 7325 13288 Marseille France

On-surface synthesis under ultrahigh vacuum provides a promising strategy to control matter at the atomic level, with important implications for the design of new two-dimensional materials having remarkable electronic, magnetic, or catalytic properties. This strategy must address the problem of limited extension of the domains due to the irreversible nature of covalent bonds, which prevents the ripening of defects. We show here that extended materials can be produced by a controlled co-deposition process. In particular, co-deposition of quinoid zwitterion molecules with iron atoms on a Ag（111） surface held at 570 K allows the formation of micrometer-sized domains based on covalent coordination bonds. This work opens up the construction of micrometer-scale single-layer covalent coordination materials under vacuum conditions.

关键词： on-surface synthesis scanning tunnelingmicroscopy (STM) two-dimensional polymer covalent organic frameworks

Pressure and temperature effects resulting from impact onto materials of different reactivity

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Defence Technology(防务技术) 2025年第2期44卷 221-230页

作者： Andreas Heine Matthias Wickert Fraunhofer Institute for High-Speed Dynamics Ernst-Mach-InstitutEMIErnst-Zermelo-Str.4Freiburg im Breisgau79104Germany

The pressure and temperature increase resulting from the impact of different threats onto target materials is analyzed with a unified laboratory-scale *** allows deriving qualitative information on the occurring phenomenology as well as quantitative statements about the relative effects sizes as a function of target material and *** considered target materials are steel,aluminum,and *** threats,kinetic energy penetrator,explosively formed projectile,and shaped charge jet are *** the investigated combinations,the measured overpressures vary by a factor of up to 5 for a variation of the material,by a factor of up to 7 for a variation of the threat,and by a factor larger than 15for a simultaneous variation of *** obtained results as well as the experimental approach are relevant for the basic understanding of impact effects and risks due to material *** paper combines two main ***,to provide a summary of own prior work in a coherent journal article and,secondly,to review and discuss these earlier results with a new perspective.

关键词： impact effects Pressure Temperature Risk assessment Material reactivity

Gravity-Driven Instability in a Liquid Film Overlying an Inhomogeneous Porous Layer

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Chinese Physics Letters 2011年第2期28卷 144-147页

作者： ZHAO Si-Cheng LIU Qiu-Sheng NGUYEN-THI Henri BILLIA Bernard Key Laboratory of Microgravity Institute of MechanicsChinese Academy of SciencesBeijing 100190 im2np UMR CNRS 6137Universitéd’Aix-Marseille III13397 Marseille Cedex 20France

A new model consisting of a liquid film overlying a saturated and inhomogeneous porous layer is *** concentrate on effects of inhomogeneity on transition of instability *** of the averaged porosity and the gradient of porosity distribution on the instability behaviors of a liquid-porous layer system are *** average permeability of the porous layer is a key factor to determine the penetration of convection in the system.

关键词： porosity porous layer

Three-Dimensional Linear Instability Analysis of Thermocapillary Return Flow on a Porous Plane

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Chinese Physics Letters 2010年第2期27卷 165-168页

作者：赵思诚刘秋生 NGUYEN-THI Henri BILLIA Bernard Key Laboratory of Microgravity Institute of Mechanics Chinese Academy of Sciences Beijing 100190 im2np UMR CNRS 6137 Université d'Aix-Marseille III 13397 Marseille Cedex 20 France

A three-dimensional linear instability analysis of thermocapillary convection in a fluid-porous double layer system, imposed by a horizontal temperature gradient, is performed. The basic motion of fluid is the surface-tension-driven return flow, and the movement of fluid in the porous layer is governed by Darcy＇s law. The slippery effect of velocity at the fluid-porous interface has been taken into account, and the influence of this velocity slippage on the instability characteristic of the system is emphasized. The new behavior of the thermocapillary convection instability has been found and discussed through the figures of the spectrum.

关键词： Fluid dynamics

The potentially crucial role of quasi-particle interferences for the growth of silicene on graphite

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Nano Research 2020年第9期13卷 2378-2383页

作者： Fatme Jardali Christoph Lechner Maurizio De Crescenzi Manuela Scarselli Isabelle Berbezier Paola Castrucci Holger Vach LPICM CNRSEcole PolytechniqueIP ParisPalaiseau 91128France Dipartimento di Fisica Universita di Roma"Tor Vergata"Roma 00133Italy CNRS Aix-Marseille UniversiteIM2NPMarseille 13397France

A comprehensive picture of the initial stages of silicene growth on graphite is *** is shown that quasiparticle interferences play a crucial role in the formation of the observed silicene *** propose,on one hand,that the charge modulations caused by those quantum interferences serve as templates and guide the incoming Si atoms to self-assemble to the unique(√3 x√3)R30°honeycomb atomic *** the other hand,their limited extension limits the growth to about 150 Si atoms under our present deposition *** here proposed electrostatic interaction finally explains the unexpected stability of the observed silicene islands over time and with *** the robust guiding nature of those quantum interferences during the early growth phase,we demonstrate that the window of experimental conditions for silicene growth is quite narrow,making it an extremely challenging experimental ***,it is shown that the experimentally observed threedimensional silicon clusters might very well be the simple result of the end of the silicene growth resulting from the limited extent of the quasi-particle interferences.

关键词： silicene growth highly oriented pyrolytic graphite(HOPG) ab initio calculations scanning tunneling microscopy(STM) quasi-particle interferences two-dimensional(2D)self-assembly

Solutal Convection of Liquid Al-3.5 wt%Li during Its Upward Solidification

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Chinese Physics Letters 2016年第6期33卷 53-56页

作者：赵思诚刘秋生 Henri Nguyen-Thi Bernard Billia Department of Mechanics School of Civil EngineeringBeijing Jiaotong University Jiangsu Key Laboratory of Engineering Mechanics Southeast University Key Laboratory of Microgravity Institute of MechanicsChinese Academy of Sciences im2np UMR CNRS 6137Universite d'Aix-Marseille

The onset of solutal convection during the directional solidification of Bridgman type of liquid Al-3.5 wt%Li is studied. Based on the analysis of a liquid-inhomogeneous-porous-double-layer system, a bimodal feature of neutral stability curve is found. The pulling rate is ascertained as the governing parameter for the mode transition, i.e., it determines whether the microstructure in the mushy layer is related to convection after the system destabilizes.

关键词： in it of is mode for Li Al

Revisiting dynamics and models of microsegregation during polycrystalline solidification of binary alloy

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Journal of Materials Science & Technology 2021年第15期74卷 155-167页

作者： Tongzhao Gong Yun Chen Shanshan Li Yanfei Cao Dianzhong Li Xing-Qiu Chen Guillaume Reinhart Henri Nguyen-Thi Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China Aix Marseille Univ Universite de ToulonCNRSIM2NPMarseilleFrance

Microsegregation formed during solidification is of great importance to material *** conventional Lever rule and Scheil equation are widely used to predict solute ***,these models always fail to predict the exact solute concentration at a high solid fraction because of theoretical ***,the dynamics of microsegregation during polycrystalline solidification of refined Al-Cu alloy is studied via two-and three-dimensional quantitative phase-field *** with different grain refinement level,cooling rate,and solid diffusion coefficient demonstrate that solute segregation at the end of solidification(*** the solid fraction is close to unit)is not strongly correlated to the grain morphology and back *** independences are in accordance with the Scheil equation which only relates to the solid fraction,but the model predicts a much higher liquid concentration than ***,based on the quantitative phase-field simulations,a new analytical microsegregation model is *** the Scheil equation or the Lever rule that respectively overestimates or underestimates the liquid concentration,the present model predicts the liquid concentration in a pretty good agreement with phase-field simulations,particularly at the late solidification stage.

关键词： Microsegregation Grain refinement Cooling rate Back diffusion Phase-field method

Normalized Area Solar Cell and Potential Applications

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Journal of Applied Mathematics and Physics 2017年第5期5卷 1106-1112页

作者： Marcel Pasquinelli Jean-Jacques Simon Judikael Le Rouzo Fran?ois Flory Ludovic Escoubas Aix Marseille Université CNRS Université de Toulon IM2NP UMR 7334 Marseille France

Nowadays in laboratories and in industries, distribution of solar cells sizes could be very large, hence;for the first time it is rather difficult to compare photovoltaic parameters which are size dependent (current, serial resistance, shunt resistance...) and performances of these cells. Also, it will be useful for scale effect to extrapolate performances calculated on a unit size solar cell to commercial products, especially in the case of heterogeneous wafers used for the device.

关键词： Photovoltaic Solar Cell Efficiency Serial Resistance Shunt Resistance

Steric and electronic selectivity in the synthesis of Fe- 1,2,4,5-tetracyanobenzene （TCNB） complexes on Au（111）： From topological confinement to bond formation

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Nano Research 2014年第6期7卷 888-897页

作者： Shawulienu Kezilebieke Anis Amokrane Mauro Boero Sylvain Clai Mathieu Abel Jean-Pierre Bucher Institut de Physique et Chimie des Materiaux de Strasbourg CNRS UMR 7504 Universit~ de Strasbourg F-67034 Strasbourg France Universite Aix-Marseille IM2NP CNRS UMR 7334 Campus de Saint-Jereme Case 142 F- 13397 Marseille Cedex 20 France

A study of the surface assisted self-assembly of 1,2,4,5-tetracyanobenzene （TCNB） acceptor molecules and Fe atoms on an Au（111） surface is presented. While conditions to get the two-dimensional arrays of stable Fe（TCNB）4 complexes are clearly identified, ultrahigh vacuum scanning tunneling microscopy and spectroscopy （STM/STS） coupled with first-principles calculations reveals that situations may occur where Fe and TCNB survive on the surface （as Fe-4TCNB entities） at a higher density than the original molecular monolayer without forming coordination bonds with each other. It is found that the square planar coordination of the Fe（TCNB）4 monomer complexes cannot fully develop in the presence of lateral strain due to growth-induced confinement. A phenomenon similar to steric hindrance involving a strongly modified chirality with a Fe-N-C bond angle of 120° compared to the 180° for the stable complex may then explain why the Fe atom keeps its metallic bond with the surface. The competition between steric and electronic effects, not reported before, may arise elsewhere in surface chemistry involved in the synthesis of new and potentially useful organic nanomaterials.

关键词： scanning tunnelingspectroscopy STM self-assembly steric hindrance metal-organic coordination chirality nanochemistry surface state