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Surface Effects on Wannier Excitons in Superlattices:Monte Carlo Simulation

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Chinese Physics Letters 2002年第8期19卷 1164-1167页

作者： K. Afif, A. Benyoussef and J. Diouri Laboratoire de Magnetisme Faculte des Sciences Groupe d"Electronique et de Physique du Solide Faculte des Science

Using a Monte Carlo quadrature, we calculate by a variational method the binding energy Eb of Wannier excitons in N-period m-CdMnTe/n-CdTe superlattices, including or not including the step discontinuity in the potential barrier at the interface, and with varying N as well as well width. The calculation is performed in the framework of the effective mass approximation for both heavy-hole and light-hole excitons. The degree of exciton localization dependence on these parameters is accurately illustrated.

关键词： Monte Carlo methods

Simulation and computational heat transfer in the human eye with Dirichlet–Neumann domain decomposition approximation

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International Journal of Modeling, Simulation, and Scientific Computing 2019年第6期10卷 107-128页

作者： Salem Ahmedou Bamba Abdellatif Ellabib Universite Cadi Ayyad Laboratoire de Mathematiques Appliquees et Informatique faculte des sciences et techniques Marrakech Avenue Abdelkrim El Khttabi B.P.549 Morocco

In this paper,a bioheat model of temperature distribution in the human eye is studied,the mathematical formulation of this model is described using adequate mathematical *** existence and the uniqueness of the solution of this problem is proven and four algorithms based on finite element method approximation and domain decomposition methods are presented in *** validation of all algorithm is done using a numerical application for an example where the analytical solution is *** properties and parameters reported in the open literature for the human eye are used to approximate numerically the temperature for bioheat model by finite element approximation and nonoverlapping domain decomposition *** obtained results that are verified using the experimental results recorded in the literature revealed a better accuracy by the use of algorithm proposed.

关键词： Nonoverlapping domain decomposition human eye bioheat transfer finite element computation

Nonoverlapping Dirichlet-Neumann method for transient bioheat transfer in the human eye

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International Journal of Biomathematics 2020年第5期13卷 97-124页

This paper presents a 2D simulation of transient heat transfer in the human eye using appropriate boundary *** mathematical model governing bioheat transfer in the human eye is discussed and the existence and uniqueness of the solution are *** methods based on finite element method and nonoverlapping domain decomposition method to obtain transient heat transfer in the human eye are presented and described in *** conducting numerous simulations using realistic parameters obtained from the open literature and after comparison with measurements reported by previous experimental studies,all proposed methods gave an accurate representation of transient heat transfer in the human *** results obtained by the domain decomposition of the human eye into four subdomains are found to be the closest to reality.

关键词： Nonoverlapping domain decomposition human eye bioheat transfer finite element met hod

The Consideration of Overlapping Lines in the Calculation of Radiative Power Emitted from CH_4 Thermal Plasma

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Plasma Science and Technology 2012年第12期14卷 1073-1078页

作者： R. BENALLAL B. LIANI Theoretical Physics Laboratory Abou Bekr Belkaid University cole prparatoire des sciences et techniques

Net emission coefficients of radiation were calculated for isothermal plasma of methane as a function of the plasma temperature 5,000 - 30,000 K and the arc radius 0 mm to 10 mm at atmospheric pressure. Calculations take into account continuum and line radiations, special attention has also been given to the influence of overlapping spectral lines. The line shapes in our calculations are given by convolution of Doppler and Lorentz profiles, resulting in a simplified Voigt profile. In the case of a hydrogen profile, we used the Vidal tables, and the four first Lyman lines and the four first Balmer lines were considered. This calculation was carried out on the assumption of local thermodynamic equilibrium and in a nondiffusive environment. The net emission coefficient calculation for pure argon plasma was compared with the experimental results of Evans in our previous work. We used the escape factor, and our results were higher than those of the experiment. In this paper, we explain why, using the escape factor, the radiation is overestimated. The net emission coefficient obtained from a real spectrum was compared with Essoltani work＇s which used the line-by-line method for pure argon plasma.

关键词： thermal plasma radiation net emission coefficient absorption coefficient

Sperm limitation affects sex allocation in a parasitoid wasp Nasonia vitripennis

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Insect Science 2019年第5期26卷 853-862页

作者： Marlene Chirault Christophe Bressac Marlene Goubault Charlotte Lecureuil Institut de Recherche sur la Biologie de I'lnsecte UMR 7261 CNRS - Universite de ToursFaculte des Sciences et TechniquesParc GrandmontToursFrance

Insect reproduction is influenced by various external factors including temperature, a well-studied constraint. We investigated to what extent different levels of sperm limitation of males exposed to different heat stresses (34 and 36℃) afFect fem ales' offspring production and sex allocation in Nasonia vitripennis. In this haplodiploid parasitoid wasp attacking different species of pest flies, we investigated the effect of the quantity of sperm females received and stored in their spermatheca on their sperm use decisions, hence sex allocation, over successive ovipositions. In particular, we compared the sex allocation of females presenting three levels of sperm limitation (i.e.,mated with control, 34 ℃ heat-stressed or 36℃heat-stressed males) on each host they parasitized. To disentangle the potential reduction of sperm quality after a heat stress exposure from that of sperm quantity, we also explored the clutch size and sex ratio produced by fem ales that were partially sperm limited after copulating with multiply mated males. Independently of their sperm numbers, all types of fem ales produced a similar total number of offspring, but the more limited ones had fewer daughters. Sperm limitation further affected the distribution of daughters' production across *** addition to constraints acting on female physiology, male fertility should therefore be considered in studies measuring reproductive outputs of insects submitted to heat stresses.

关键词： heat stress multiple mating offspring production dynamic sex ratio sperm stock sperm use

Pyrolysis of olive residue/low density polyethylene mixture：Part Ⅰ Thermogravimetric kinetics

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燃料化学学报 2008年第6期36卷 672-678页

作者： ABOULKAS A E1 HARFI K El BOUADILI A Laboratoire de Recherche sur la Reactivites des Materiaux et l Optimisation des Procedes ＂REMATOP＂ Departement de chimie Faculte des Sciences Semlalia Universite Cadi Ayyad BP 2390 40001 Marrakech Maroc Departement de chimie Faculte polydisciplinaire de Beni-Mellal Universite Sultan Moulay Slimane BP 592 23000 Beni-Mellal Maroc Laboratoire de Chimie Organique et Analytique Departement de chimie Faculte des Sciences et Techniques de Beni-Mellal Universite Sultan Moulay Slimane BP 523 23000 Beni-Mellal Maroc

This paper demonstrates the thermal pyrolysis of olive residue,low density polyethylene(LDPE) and olive residue/LDPE mixture in an inert atmosphere of N2 using thermogravimetric analysis(TGA).Measurements were carried out in the temperature range 300K^973K at heating rates of 2K/min,10K/min,20K/min and 50K/*** on the results obtained,three temperature regimes were selected for studying the non-isothermal kinetics of olive residue/LDPE *** first two were dominated by the olive residue pyrolysis,while the third was linked to the LDPE pyrolysis,which occurred at much higher *** between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on *** maximum degradation temperatures of each component in the mixture were higher than those the individual components;thus an increase in thermal stability was *** kinetic parameters associated with thermal degradation were determined using Friedman isoconversional method.

关键词：高温分解反应低密度聚乙烯动力学 LDPE

Numerical Modelling Point-to-Plane of Negative Corona Discharge in N_2 Under Non-Uniform Electric Field

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Plasma Science and Technology 2015年第6期17卷 469-474页

作者： A.K.FEROUANI M.LEMERINI L.MERAD M.HOUALEF Ecole Préparatoire en sciences et techniques Département de Physique LPT Université A.BelkaidFaculté des SciencesDépartement de Physique Ecole Préparatoire en sciences et techniques Département de Maths

The paper presents a simulation model of the negative corona discharge in N2 under various pressures. The simulated discharge is of a negative point-to-plane mass type, with an inter-electrode separation distance of 20 mm and a symmetry about the axis of discharge. This simulation investigates the behavior of the neutral density and temperature for different pressures in the range of 0.1-10.0 bar. The spatial and temporal evolution of the neutral gas is analyzed based upon the equations of continuity, momentum and energy in a two-dimensional cylindrical geometry model. For that geometry of the system, the FCT （Flux Corrected Transport） technique was adopted. The results show that the pressure plays a significant role of the neutrals dynamics.

关键词： DC corona discharge FCT method numerical simulation

Wave Kernels with Bi-Inverse Square Potentials on Euclidean Plane

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Journal of Partial Differential Equations 2015年第1期28卷 9-22页

作者： MOUSTAPHA Mohamed Vall Ould Universitd des sciences de Technologie et de la Medecine (USTM) Faculte des Sciences et Techniques. Unite de recherche: Analyse EDP et Moddlisation Facult des Sciences et Techniques Universit des sciences de Technologie et de la medecine Nouakchott BP: 5026 Mauritanie.

The Cauchy problem for the wave equation with bi-inverse square potential on Euclidean plane is solved in terms of the two variables Appell F2 hypergeometric functions. Our principal tools are the Hankel transforms an... 详细信息

关键词： Inverse square potential wave equation Hankel transform Bessl functions F2- Appell hypergeometric function.

Reconstructing f(T) modified gravity from ECHDE and ECNADE models

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Communications in Theoretical Physics 2020年第9期72卷 75-88页

作者： A E Godonou Ines G Salako M J S Houndjo etienne Baffou Joel Tossa Institut de Mathematiques et de sciences Physiques(IMSP) 01 BP 613 Porto-NovoBenin Ecole de Genie Rural(EGR) 01 BP 55 KetouBenin faculte des sciences et techniques de Natitingou(FAST) BP 72NatitingouBenin

We investigate alternative candidates to dark energy(DE) that can explain the current state of the Universe in the framework of the generalized teleparallel theory of gravity f(T), where T denotes the torsion scalar. To achieve this, we carry out a series of reconstructions taking into account the ordinary and entropy-corrected versions of the holographic and new agegraphic DE *** models are used as alternatives to DE in the literature in order to describe the current state of our Universe. It is remarked that the proposed models indicate behavior akin to phantom or quintessence models. Furthermore, we also generate the parameters of the equation of state associated with entropy-corrected models and we observe a phase transition between the quintessence state and phantom state as it is shown by the recent observational data. We also investigate the stability of these models and we create the {r-s} trajectories and compare with the ΛCDM limit. The behavior of certain physical parameters such as the speed of sound and the Statefinder diagnostic pair {r-s} is compatible with the current observational data.

关键词： teleparallel gravity ECHDE ECNADE