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On a certain non-split cubic surface

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Science China Mathematics 2019年第12期62卷 2435-2446页

作者： Regis de la Breteche Kevin destagnol Jianya Liu Jie Wu Yongqiang Zhao Institut de mathematiques de Jussieu Universite Paris-DiderotParis 75205France IST Austria Klosterneuburg 3400Austria School of Mathematics Shandong UniversityJinan 250100China laboratoire d'analyse et de mathematiques appliquees Univer site Paris-Est CreteilCNRSUMR 8050Creteil 94010France School of Science Westlake UniversityHangzhou 310024China

This paper establishes an asymptotic formula with a power-saving error term for the number of rational points of bounded height on the singular cubic surface of P3 Qgiven by the following equation x0（x12+ x22）-x33= ... 详细信息

关键词： Manin-Peyre conjecture rational points singular cubic surface non-split toric surface descent on torsors asymptotic formula

Mg(OH)_2 Nanorods Synthesized by A Facile Hydrothermal Method in the Presence of CTAB

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Nano-Micro Letters 2011年第3期3卷 153-159页

作者： Hassouna Dhaouadi Hedia Chaabane Fathi Touati "laboratoire des Matriaux Utiles" Institut National de Recherche et d’analyse Physico-chimique Ple technologique de Sidi-Thabet "laboratoire de Microbiologie" Institut National de Recherche et d’analyse Physico-chimique Ple technologique de Sidi-Thabet

Magnesium hydroxide(Mg(OH)_2) nanorods were synthesized by a simple and facile hydrothermal method in the presence of cetyltetramethylammonium bromide(CTAB) as a surfactant. Nanorods of magnesium oxide Mg O were also induced by thermal decomposition of Mg(OH)_2 nanorods at 700. By using disk diffusion technique, the Mg(OH)_2 nanorods were found to exhibit higher antibacterial efficiency against several tested bacterial strains.

关键词： Nanorods Morphology Hydrothermal synthesis

Physico-chemical and mechanical properties of Ti_3SiC_2-based materials elaborated from SiC/Ti by reactive spark plasma sintering

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Journal of Advanced Ceramics 2019年第1期8卷 47-61页

作者： Faten TURKI Houyem ABdeRRAZAK Frédéric SCHOENSTEIN Florent TêTARD Mohieddine ABdeLLAOUI Noureddine JOUINI laboratoire des Matériaux Utiles Institut National de Recherche et d’Analyse Physico-chimique laboratoire de Sciences des Procédés et Matériaux Université Paris 13 Sorbonne Paris Cité CNRS

In this paper, the synthesis of Ti_3 SiC_2 from SiC/Ti powder using reactive spark plasma sintering(R-SPS) in the temperature range of 1300-1400 ℃ is reported. The results show that the purity of Ti_3 SiC_2 is improved up to 75 wt% when the holding time is increased from 10 to 20 min at1400 ℃. The thermodynamic and experimental results indicate that Ti_3 SiC_2 formation takes place via the reaction of a pre-formed TiC phase with the silicides, formed from the eutectic *** analysis of mechanical behaviour indicates that samples with higher percentage of secondary phases exhibit higher microhardness and better resistance compared to the near single phase Ti_3 SiC_2.

关键词： Ti3SiC2 reactive spark plasma sintering(R-SPS) density mechanical properties

density Results in Sobolev Spaces Whose Elements Vanish on a Part of the Boundary

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Chinese Annals of Mathematics,Series B 2011年第6期32卷 823-846页

作者： Jean-Marie Emmanuel BERNARD laboratoire analyse et Probabitilités Université d'Evry val d'Essonne23 Boulevard de France91037 EVRYFrance

This paper is devoted to the study of the subspace of Wm＇＂ of functions that vanish on a part γ0 of the boundary. The author gives a crucial estimate of the Poincare constant in balls centered on the boundary of γ0. Then, the convolution-translation method, a variant of the standard mollifier technique, can be used to prove the density of smooth functions that vanish in a neighborhood of γ0, in this subspace. The result is first proved for m = 1, then generalized to the case where m 〉 1, in any dimension, in the framework of Lipschitz-continuous domain. However, as may be expected, it is needed to make additional assumptions on the boundary of γ0, namely that it is locally the graph of some Lipschitz-continuous function.

关键词： density results Boundary value problems Sobolev spaces

Effect of Water Quality on Heavy Metal Redistribution and Mobility in Polluted Agricultural Soils in a Semi-Arid Region

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Pedosphere 2019年第6期29卷 730-739页

作者： Rim AZOUZI Abdelkrim CHAREF Lamia AYED Samia KHADHAR laboratoire Géoressources Centre des Recherches et Technologies des EauxSoliman 8020(Tunisia) laboratoire d’analyse Traitement et Valorisation des Polluants de l’Environnement et des ProduitsFacultéde PharmacieRue AvicenneMonastir 5000(Tunisia)

Mornag Plain is a coastal area of the Mediterranean basin, which has undergone an agricultural industrial boom. The aim of this study was to investigate the different water qualities used for irrigation on heavy metal mobility in these polluted agricultural soils. The geo-accumulation indices for heavy metals (Ni, Cr, Pb, Cd, Cu, and Zn) revealed that industrial activities and used treated wastewater (TWW) contributed to soil pollution, and water irrigation always decreased this contamination. After long-term use of different water types, high perturbation of heavy metal redistribution has occurred. Groundwater use altered all heavy metal redistributions in the irrigated soil among various soil-solid and soil-solution fractions, as compared to the unirrigated soil. Slight acid water use transferred some metals from different solid phase components into water-soluble and exchangeable fractions. However, TWW use transformed some Ni, Cr, Cd, Cu, and Zn from water-soluble and exchangeable fractions to less labile fractions, particularly into organically bound fractions. Reuse of conventional water within the same soil decreased the whole soil redistribution index values, indicating tendency to return to the pattern of distribution of groundwater-irrigated soil.

关键词： Exchangeable fraction Geo-accumulation index Labile fraction Mobility factor Organically bound fraction Redistribution index Treated wastewater Water-soluble fraction

Semi-classical analysis on H-type groups dedicated to Professor Jean-Yves Chemin on the Occasion of His 60th Birthday

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Science China Mathematics 2019年第6期62卷 1057-1086页

作者： Clotilde Fermanian Kammerer Véronique Fischer Université Paris-Est Laboratoire d’Analyse et de Mathématiques Appliquées (UMR 8050) department of Mathematical Sciences University of Bath

In this paper, we develop semi-classical analysis on H-type groups. We define semi-classical pseudodifferential operators, prove the boundedness of their action on square integrable functions and develop a symbolic calculus. Then, we define the semi-classical measures of bounded families of square integrable functions which consist of a pair formed by a measure defined on the product of the group and its unitary dual, and by a field of trace class positive operators acting on the Hilbert spaces of the representations. We illustrate the theory by analyzing examples, which show in particular that this semi-classical analysis takes into account the finite-dimensional representations of the group, even though they are negligible with respect to the Plancherel measure.

关键词： H-type groups semi-classical pseudodifferential operators semi-classical measures Wigner transform asymptotic analysis microlocal analysis

Numerical inversion method for the Laplace transform based on Boubaker polynomials operational matrix

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International Journal of Modeling, Simulation, and Scientific Computing 2022年第1期13卷 251-264页

作者： Rachid Belgacem Ahmed Bokhari Salih djilali Sunil Kumar Faculty of Exact and Computer Sciences Mathematic Department Hassiba Benbouali UniversityChlefAlgeria Laboratory of Mathematics and its Applications(LMA)Faculty of Exact and Computer Sciences Hassiba Benbouali University ChlefAlgeria laboratoire d’analyse Non Lineaire et mathematiques appliquees Universite de Tlemcen TlemcenAlgeria department of Mathematics National Institute of Technology Jamshedpur 831014JharkhandIndia

We investigate through this research the numerical inversion technique for the Laplace transforms cooperated by the integration Boubaker polynomials operational *** efficiency of the presented approach is demonstrated by solving some differential ***,this technique is combined with the standard Laplace Homotopy Per-turbation *** numerical results highlight that there is a very good agreement between the estimated solutions with exact solutions.

关键词： Laplace transform Boubaker polynomials operational matrix homotopy per-turbation method numerical method

ASYMPTOTIC ANALYSIS OF LINEARLY ELASTIC SHALLOW SHELLS WITH VARIABLE THICKNESS

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Chinese Annals of Mathematics,Series B 2001年第4期22卷 405-416页

作者： N. SABU laboratoire d’analyse Numerique, Universite Pierre et Marie Curie, 4 Place Jussieu, 75005, Paris, France.E-mail: sabu@ann.jussieu.fr laboratoire d'analyse Numerique Université Pierre et Marie Curie 4 Place Jussieu 75005 Paris France

The author considers a linearly elastic shallow shell with variable thickness and shows that, as the thickness of the shell goes to zero, the solution of the three-dimensional equations converges to the solution of th... 详细信息

关键词： Asymptotic analysis Elastic shallow shells Vaiable thickness

EXISTENCE OF MINIMIZING SOLUTIONSAROUND“EXTENdeD STATES”FOR A NONLINEARLY ELASTICCLAMPED PLANE MEMBRANE

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Chinese Annals of Mathematics,Series B 1999年第3期20卷 279-296页

作者： D. COUTAND(University of Pierre et Marie Curie, laboratoire d’analyse Numerique, 4, Place Jussieu, 75005 Paris,France. E-mail: coutand@ann.jussieu.fr) Université of Pierre et Marie Curie Laboratoire d'Analyse Numérique 4 Place Jussieu 75005 Paris France

The formal asymptotic analysis of D. Fox, A. Raoult & J.C. Simo[10] has justified the twodimensional nonlinear "membrane" equations for a plate made of a Saint Venant-Kirchhoff *** model, which retains the material-frame indifference of the original three dimensional problem in the sense that its energy density is invariant under the rotations of R3, is equivalent to finding the critical points of a functional whose nonlinear part depends on the first fundamental form of the unknown deformed *** author establishes here, by the inverse function theorem, the existence of an injective solution to the clamped membrane problem around particular forces corresponding physically to an "extension" of the membrane. Furthermore, it is proved that the solution found in this fashion is also the unique minimizer to the nonlinear membrane functional, which is not sequentially weakly lower semi-continuous.

关键词： Minimizing solution Nonlinearly elastic clamped plane membrane Injective Solution