Le français en usage- Faits d'appropriation- La néologie lexicale

Le français en usage- Faits d'appropriation- Lanéologie lexical

Critical Properties and Exchange Interactions of Antiferromagnetic A-spinel Lattice: A Study Through High-temperature Series Expansions

We derive high- temperature series expansions for the spin correlation functions of the A-spinel lattice. The development is extended to the order 6 in β = 1/KBT with nearest-neighbour and next-nearest neighbour interactions. The results are given for various neighbour correlation functions (up to the third). The behaviour with the temperature is presented. The critical region is studied by applying the Padé approximants method to the corresponding high- temperature series expansion of the magnetic susceptibility and the correlation length. The approach is applied to the experimental results of the particular system A-spinel CoCo2O4 . The following estimates are obtained for the familiar critical exponents:  γ =  1.382±0.010 and ν =  0.701±0.012.We derive high- temperature series expansions for the spin correlation functions of the A-spinel lattice. The development is extended to the order 6 in β = 1/KBT with nearest-neighbour and next-nearest neighbour interactions. The results are given for various neighbour correlation functions (up to the third). The behaviour with the temperature is presented. The critical region is studied by applying the Padé approximants method to the corresponding high- temperature series expansion of the magnetic susceptibility and the correlation length. The approach is applied to the experimental results of the particular system A-spinel CoCo2O4 . The following estimates are obtained for the familiar critical exponents:  γ =  1.382±0.010 and ν =  0.701±0.012

De quelques emplois auxiliaires de voir

De quelques emplois auxiliaires de voi

Spinal Infections: An Update

Spinal infection poses a demanding diagnostic and treatment problem for which a multidisciplinary approach with spine surgeons, radiologists, and infectious disease specialists is required. Infections are usually caused by bacterial microorganisms, although fungal infections can also occur. The most common route for spinal infection is through hematogenous spread of the microorganism from a distant infected area. Most patients with spinal infections diagnosed in early stages can be successfully managed conservatively with antibiotics, bed rest, and spinal braces. In cases of gross or pending instability, progressive neurological deficits, failure of conservative treatment, spinal abscess formation, severe symptoms indicating sepsis, and failure of previous conservative treatment, surgical treatment is required. In either case, close monitoring of the patients with spinal infection with serial neurological examinations and imaging studies is necessary

Study of the spin correlation and the percolation threshold in the B-site spinel

High-temperature series expansion of the correlation function on the B- spinel lattice are computed up to order 6 in β = 1/(kBT) for Heisenberg model including both the nearest and next-nearest-neighbor interactions J1 and J2 respectively. The behavior with the temperature and the site dilution is presented. The approach is applied to the experimental results of the B-spinel ZnCr2xAl2-2xS4. The critical temperature and the critical exponents for the susceptibility and the correlation length are deduced by applying the Padé approximant methods. The following estimates are obtained for the familiar critical exponents: γ=1.382±0.012 and ν = 0.691±0.011. These values are not sensitive to the dilution ratio x. The bond percolation threshold xp is determined by studying the disorder variation of the correlation length ξ. The xp is considered as the concentration at which ξ vanishes. The obtained values are xp =0.27 when only J1 is considered and 0.23 when both J1 and J2 are considered.High-temperature series expansion of the correlation function on the B- spinel lattice are computed up to order 6 in β = 1/(kBT) for Heisenberg model including both the nearest and next-nearest-neighbor interactions J1 and J2 respectively. The behavior with the temperature and the site dilution is presented. The approach is applied to the experimental results of the B-spinel ZnCr2xAl2-2xS4. The critical temperature and the critical exponents for the susceptibility and the correlation length are deduced by applying the Padé approximant methods. The following estimates are obtained for the familiar critical exponents: γ=1.382±0.012 and ν = 0.691±0.011. These values are not sensitive to the dilution ratio x. The bond percolation threshold xp is determined by studying the disorder variation of the correlation length ξ. The xp is considered as the concentration at which ξ vanishes. The obtained values are xp =0.27 when only J1 is considered and 0.23 when both J1 and J2 are considered

Phase diagrams of site diluted ferromagnetic semi infinite system

The spin correlations functions of face-centered cubic semi-infinite system are investigated by using the high  temperature series expansions extrapolated with the Padé approximant method for Heisenberg, XY and Ising models. The magnetic phase diagrams tc(n) versus the dilution x are obtained. The value obtained of the percolation threshold is. Xp≈0.2 The Xp is defined as the concentration at which tc =0The spin correlations functions of face-centered cubic semi-infinite system are investigated by using the high  temperature series expansions extrapolated with the Padé approximant method for Heisenberg, XY and Ising models. The magnetic phase diagrams tc(n) versus the dilution x are obtained. The value obtained of the percolation threshold is. Xp≈0.2 The Xp is defined as the concentration at which tc =

Phase diagrams of site diluted semi infinite ferromagnetic film

The magnetic susceptibility of a semi-infinite ferromagnetic films with a simple cubic lattice and the face centered cubic lattice is investigated by the method of exact high-temperature series expansions (HTSE) extrapolated with the Padé approximants method for Heisenberg, XY and Ising models. The magnetic phase diagrams in (tc (ν), c) plane are obtained. The value of the percolation threshold Xp is obtained. The Xp is defined at which tc= 0.The magnetic susceptibility of a semi-infinite ferromagnetic films with a simple cubic lattice and the face centered cubic lattice is investigated by the method of exact high-temperature series expansions (HTSE) extrapolated with the Padé approximants method for Heisenberg, XY and Ising models. The magnetic phase diagrams in (tc (ν), c) plane are obtained. The value of the percolation threshold Xp is obtained. The Xp is defined at which tc= 0

THEORETICAL INVESTIGATION OF THE LEVEL ENERGIES FOR IDEAL Ga AND As VACANCIES IN GaAs

The bound state energies of ideal Ga and As vacancies in GaAs have been studied in the Green’s-function framework in conjunction the tight-binding method. Using existing data for band structures, the Koster-Slater parameters have been estimated, the energy levels at critical points and the density of states in perturbed and unperturbed crystal have been calculated. The unrelaxed vacancy of Ga and As introduces bound state at 0.05 eV and 1.46 eV respectively above the valence band edge. These results provide justification to experimental data based on irradiation of GaAs by energetic neutrons.The bound state energies of ideal Ga and As vacancies in GaAs have been studied in the Green’s-function framework in conjunction the tight-binding method. Using existing data for band structures, the Koster-Slater parameters have been estimated, the energy levels at critical points and the density of states in perturbed and unperturbed crystal have been calculated. The unrelaxed vacancy of Ga and As introduces bound state at 0.05 eV and 1.46 eV respectively above the valence band edge. These results provide justification to experimental data based on irradiation of GaAs by energetic neutrons

Fonctionnement hydrogéochimique d'un réservoir polymictique chaud : cas du réservoir Daourat (Maroc)

Le réservoir du barrage Daourat a fait l'objet, au cour du cycle hydrologique 1996-1997, d'une étude pour comprendre le fonctionnement hydrogéochimique du réservoir. Le régime hydrologique du réservoir Daourat (9,5 Mm3) résulte des apports externes et de la gestion propre du réservoir. La colonne d'eau ne présente aucune période de stratification (lac polymictique chaud) ni d'anoxie. L'influence des réservoirs situés en amont (Al Massira 2 800 Mm3 et Imfout 18 Mm3) ne permet pas d'expliquer le fonctionnement biogéochimique du réservoir Daourat. Cette retenue semble être beaucoup plus contrôlée par les apports du bassin versant local et par la charge interne du réservoir.The study of the Daourat reservoir during the hydrological cycle 1996-1997, focus on the water column and the sediment in order to understand the hydrogeochemical functioning. The hydrological mode of the Daourat reservoir (9,5 Mm3) is a result of the external contributions of the area catchment and the management of the reservoir. The water column of this reservoir does not present any period of stratification and any period of anoxia. It is a warm polymictic lake. The influence of the upstream reservoir (Al Massira 2 800 Mm3 and Imfout 18 Mm3) does not explain the physicochemical and geochemical functioning of the Daourat reservoir. Indeed, this reservoir seems to be much more controlled by the contributions of the local area catchment and by the internal load of the reservoir