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Chinese Physics B 2015年第10期24卷 359-365页

作者： Youcef Megrouss Nadia Benhalima Rawia Bahoussi Nouredine Boukabcha Abdelkader Chouaih Fodil Hamzaoui Laboratoire de technologie et Proprietedu Solide(LTPS) University of Mostaganem

This work is devoted to the experimental determination of the electrostatic properties of the molecular 4-methyl-7-（salicylidene amino） coumarin（C17H13NC3） using high resolution x-ray diffraction data. The experimental results are compared with those obtained theoretically from calculation type ab initio. The experimental investigation is carried out using the molecular electron charge density distribution based on the multipolar model of Hansen and Coppens. However the theoretical calculations are conducted by using the molecular orbital B3 LYP method and the Hartree-Fock（HF） approximation with the basis set 6-31G（d,p） implemented in the Gaussian program. In addition to the structural analysis,the thermal agitation is also analyzed in terms of rigid blocks to ensure a better precision of the results. Subsequently, the electrostatic atomic and molecular properties such as the net charges, the molecular dipolar moment to highlight the nature of charge transfer existing within the molecule studied are derived. Moreover, the obtained electrostatic potential enables the localization of the electropositive and the electronegative parts of the investigated molecule. The present work reports in detail the obtained electrostatic properties of this biologically important molecule.

关键词： electron charge density electrostatic potential molecular dipole moment and x-ray diffraction

Soliton excitations in a polariton condensate with defects

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Chinese Physics B 2018年第1期27卷 278-283页

作者： Abderahim Mahmoud Belounis Salem Kessal SNIRM Laboratory Faculty of Physics Universite des Sciences et de la Technologie Houari Boumediene (USTHB)

To study soliton excitations in a polariton condensate with defects, we use the Gross-Pitaevskii equation and its hydrodynamic form. An extra term is added to take into account the non-equilibrium nature of the polariton condensate and the presence of defects. The reductive perturbation method transforms these hydrodynamic equations into a modified Korteweg-de Vries equation in the long wavelength limit. We linearize this equation and study the soliton linear excitations. We give an analytic expression of traveling excitations using the variation of constants method. In the more general form, we show numerically that the excitations are oscillations simultaneously hut in an opposite way. i.e., the amplitude and the width of the dark soliton oscillate

关键词： solitons polariton condensates reductive perturbation method

Assessment of ship manoeuvrability by using a coupling between a nonlinear transient manoeuvring model and mathematical programming techniques

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Journal of Hydrodynamics 2013年第5期25卷 788-804页

作者： TRAN KHANH Toan OUAHSINE Abdellatif NACEUR Hakim EL WASSIFI Karima Laboratoire Roberval Université de Technologie de Compiègne Laboratoire LAMIH Université de Valenciennes Université Cadi Ayyad Faculté des Sciences et Techniques

In this paper, a numerical method based on a coupling between a mathematical model of nonlinear transient ship manoeuvring motion in the horizontal plane and Mathematical Programming （MP） techniques is proposed. The aim of the proposed procedure is an efficient estimation of optimal ship hydrodynamic parameters in a dynamic model at the early design stage. The proposed procedure has been validated through turning circle and zigzag manoeuvres based on experimental data of sea trials of the 190 000- dwt oil tanker. Comparisons between experimental and computed data show a good agreement of overall tendency in manoeuvring traiectories.

关键词： ship manoeuvrability hydrodynamics coefficients nonlinear transient dynamics sensitivity analysis mathematical pro- gramming

Analysis of a quasistatic contact problem with adhesion and nonlocal friction for viscoelastic materials

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Applied Mathematics and Mechanics(English Edition) 2010年第5期31卷 623-634页

作者： Arezki TOUZALINE Laboratoire de Systèmes Dynamiques Facult de Mathmatiques Universit des Sciences et de la Technologie Houari Boumediene

A mathematical model is established to describe a contact problem between a deformable body and a foundation. The contact is bilateral and modelled with a nonlocal friction law, in which adhesion is taken into account. Evolution of the bonding field is described by a first-order differential equation. The materials behavior is modelled with a nonlinear viscoelastic constitutive law. A variational formulation of the mechanical problem is derived, and the existence and uniqueness of the weak solution can be proven if the coefficient of friction is sufficiently small. The proof is based on arguments of time-dependent variational inequalities, differential equations, and the Banach fixed-point theorem.

关键词： viscoelastic materials adhesion nonlocal friction fixed point weak solution

Structural and electron charge density studies of a nonlinear optical compound 4,4 di-methyl amino cyano biphenyl

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Chinese Physics B 2014年第1期23卷 312-317页

作者： Naima Boubegra Abdelkader Chouaih Mokhtaria Drissi Fodil Hamzaoui Laboratoire de technologie et Propriétés du Solide (LTPS) Université Abdelhamid Ibn Badis de Mostaganem 27000 Mostaganem Algeria

The 4,4 dimethyl amino cyano biphenyl crystal (DMACB) is characterized by its nonlinear activity. The intra molecular charge transfer of this molecule results mainly from the electronic transmission of the electro-acceptor (cyano) and electro-donor (di-methyl-amino) groups. An accurate electron density distribution around the molecule has been calculated based on a high-resolution X-ray diffraction study. The data were collected at 123 K using graphite-monochromated Mo K α radiation to sin(β)/λ = 1.24 Å−1. The integrated intensities of 13796 reflections were measured and reduced to 6501 independent reflections with I ≥ 3σ(I). The crystal structure was refined using the experimental model of Hansen and Coppens (1978). The crystal structure has been validated and deposited at the Cambridge Crystallographic Data Centre with the deposition number CCDC 876507. In this article, we present the thermal motion and the structural analysis obtained from the least-square refinement based on F2 and the electron density distribution obtained from the multipolar model.

关键词： electron charge density 4,4 dimethyl amino cyano biphenyl crystal (DMACB) multipolar refinement

High speed sub-micrometric microscopy using optical polymer microlens

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Chinese Optics Letters 2009年第10期7卷 901-903页

作者：曾新华 J.Plain S.Jradi P.renaud Goud R.Deturche P.Royer R.Bachelot Laboratoire de Nanotechnologie et d'Instrumentation Optique ICD CNRS FRE 2848Universit de technologie de Troyes department of Physics Shanghai Jiao Tong University

We report the high speed scanning submicronic microscopy （SSM） using a low cost polymer microlens integrated at the extremity of an optical fiber. These microlenses are fabricated by a free-radical photopolymerization method. Using a polymer microlens with a radius of curvature of 250 nm, a sub-micrometric gold pattern is imaged experimentally by SSM. Different distances between the tip and the sample are used with a high scanning speed of 200 cm/s. In particular, metallic absorption contrasts are described with an optical spatial resolution of 250 nm at the wavelength of 532 nm. Moreover, finite-difference time-domain （FDTD） simulations concerning the focal lengths of microlenses with different geometries and heights support the experimental data.

关键词： Finite difference time domain method Microlenses Optical fiber fabrication Optical fibers Polymers

Robot Off-Line Programming for Thermal Spraying

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稀有金属材料与工程 2012年第S1期41卷 13-17页

作者： Christian Coddet Laboratoire d'etudes et de recherches sur les Matériaux les Procédés et les Surfaces(LERMPS)Université de Technologie de Belfort-Montbéliard(UTBM)Belfort Cedex 90010French

The purpose of this study is to introduce the current applications of off-line programming technology in thermal spraying,including some popular methods of path generation,procedure simulation,robot kinematics optimization,*** this technology reduces the difficulty of robot programming and enormously improves its facility for thermal *** the last part of this paper,presented two examples of off-line programming in thermal spraying which refer to trajectory optimization on a work piece with a great angle and path generation on the complex work *** simulations and experiments have proved that off-line programming can effectively improve the production efficiency and the quality of coating.

关键词： off-line programming toolkit thermal spraying trajectory optimization

AN IMPROVED BRANCH-AND-BOUND ALGORITHM TO MINIMIZE THE WEIGHTED FLOWTIME ON IdeNTICAL PARALLEL MACHINES WITH FAMILY SetUP TIMES

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Journal of Systems Science and Systems Engineering 2008年第4期17卷 446-459页

作者： Belgacem BetTAYEB Imed KACEM Kondo H.ADJALLAH LOSI-ICD CNRS Fre 2848 Université de technologie de Troyes France

This article investigates identical parallel machines scheduling with family setup times. The objective function being the weighted sum of completion times, the problem is known to be strongly NP-hard. We propose a constructive heuristic algorithm and three complementary lower bounds. Two of these bounds proceed by elimination of setup times or by distributing each of them to jobs of the corresponding family, while the third one is based on a lagrangian relaxation. The bounds and the heuristic are incorporated into a branch-and-bound algorithm. Experimental results obtained outperform those of the methods presented in previous works, in term of size of solved problems.

关键词： Scheduling heuristic lower bound branch-and-bound algorithm identical parallel machines family setup times

BEST APPROXIMATION FOR WEIERSTRASS TRANSFORM CONNECTED WITH SPHERICAL MEAN OPERATOR

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Acta Mathematica Scientia 2012年第2期32卷 455-470页

作者： L.T.Rachdi N.Msehli Département de Math'ematiques Facult'e des Sciences de Tunis2092 El-ManarTunisia Département de Mathématiques et d'informatique Institut National des Sciences Appliquées et de Technologie de Tunis1080 TunisTunisia

Using reproducing kernels for Hilbert spaces, we give best approximation for Weierstrass transform associated with spherical mean operator. Also, estimates of extremal functions are checked.

关键词： Weierstrass transform spherical mean operator best approximation repro-ducing kernel extremal function

Numerical investigation of Ar–NH3 mixture in homogenous DBDs

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Plasma Science and Technology 2018年第3期20卷 72-77页

作者： Barkahoum LAROUCI Soumia BENdeLLA Ahmed BELASRI Laboratoire de Physique des Plasmas Materiaux Conducteurs et leurs Applications Faculte de PhysiqueUniversite des Sciences et de la Technologie d'Oran Mohamed Boudiaf USTO-MB El M'Naoeur B.P.1505 31 000 Oran Algeria

In this paper, a study of homogenous dielectric barrier discharge Ar–NHwas made in order to investigate the electrical and the physical characteristics of homogenous discharge at atmospheric pressure. The discharge model includes the electrical module and the chemical kinetic module. The results obtained by the present model were compared with experimental work. The evolution of the plasmas voltage, the species densities, and the concentration of charged species are analyzed and discussed.

关键词： plasma simulation dielectric barrier discharge Ar-NH3 mixture