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91.
M. Alaoui Lamrani Z. Sofiani B. Sahraoui A. El Hichou J.C. Bernède 《Optics Communications》2007,277(1):196-201
We have deposited zinc oxide (ZnO) and erbium doped zinc oxide (ZnO:Er) thin films on heated glass substrates using spray pyrolysis technique. The effect of erbium dopant on structural, morphological, luminescent and nonlinear optical properties was studied. The deposited films have been analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), ex situ compositional analysis (ESCA), profilometry, cathodoluminescence (CL) and third harmonic generation (THG) measurements. All films were polycrystalline, having a preferential growth orientation along the ZnO (0 0 2) plane, with a corresponding average crystallite size of less than 41 nm. Addition of erbium can effectively control the film surface morphology and its cathodoluminescent properties. The films containing low erbium concentration show a uniform surface covered with hexagonal shaped grains and a strong UV light emission intensity as well as TH response. In contrast, when the erbium doping ratio exceeds 3%, a porous surface with columnar textural growth becomes more pronounced, and a substantial reduction of the cathodoluminescent and TH response. A strong TH signal was obtained for the film with good crystalline quality at the concentration of 2%. Third order nonlinear optical susceptibility (χ〈3〉) values of the studied materials were in the remarkable range of 10−12 esu. 相似文献
92.
In this paper, we propose a graph-transformational approach to swarm computation that is flexible enough to cover various existing notions of swarms and swarm computation, and it provides a mathematical basis for the analysis of swarms with respect to their correct behavior and efficiency. A graph transformational swarm consists of members of some kinds. They are modeled by graph transformation units providing rules and control conditions to specify the capability of members and kinds. The swarm members act on an environment—represented by a graph—by applying their rules in parallel. Moreover, a swarm has a cooperation condition to coordinate the simultaneous actions of the swarm members and two graph class expressions to specify the initial environments on one hand and to fix the goal on the other hand. Semantically, a swarm runs from an initial environment to one that fulfills the goal by a sequence of simultaneous actions of all its members. As main results, we show that cellular automata and particle swarms can be simulated by graph-transformational swarms. Moreover, we give an illustrative example of a simple ant colony the ants of which forage for food choosing their tracks randomly based on pheromone trails. 相似文献
93.
Giahi A El Alaoui Faris M Bassereau P Salditt T 《The European physical journal. E, Soft matter》2007,23(4):431-437
In view of recent theories of “active” membranes, we have studied multilamellar phospholipid membrane stacks with reconstituted
transmembrane protein bacteriorhodopsin (BR) under different illumination conditions by X-ray scattering. The light-active
protein is considered as an active constituent which drives the system out of equilibrium and is predicted to change the collective
fluctuation properties of the membranes. Using X-ray reflectivity, X-ray non-specular (diffuse) scattering, and grazing incidence
scattering, we find no detectable change in the scattering curves when changing the illumination condition. In particular
the intermembrane spacing d remains constant, after eliminating hydration-related artifacts by design of a suitable sample environment. The absence of
any observable non-equilibrium effects in the experimental window is discussed in view of the relevant parameters and recent
theories. 相似文献
94.
95.
96.
Irene Ara Fatima El Bahij Mohamed Lachkar Najib Ben Larbi 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):m199-m200
The Pd atom in the title compound, [Pd(C3H5OS2)2], lies on an inversion center and adopts a square‐planar coordination geometry defined by the four S atoms of the two dithiocarbonate (xanthate) ligands. In the solid state, the molecules aggregate into layers in which the rows of molecules alternate their orientation to allow each Pd atom to interact with two symmetry‐equivalent S atoms of the xanthate ligands of adjacent molecules, generating a pseudo‐octahedral environment around each Pd atom. This weak interaction of 3.3579 (7) Å can be classified as a closed‐shell electrostatic intermolecular interaction. 相似文献
97.
Aboufaris EL Alaoui S. M. Ghallali L. EL Guendouzi M. Benbiyi A. 《Journal of solution chemistry》2022,51(7):802-815
Journal of Solution Chemistry - In this investigation, calculated and experimental solubilities of the binary aqueous solutions of dipotassium hydrogenphosphate and disodium hydrogenphosphate have... 相似文献
98.
Aicha Henien Larbi Ait-Hennani Jacques Demongeot Ali Laksaci Mustapha Rachdi 《Comptes Rendus Mathematique》2018,356(5):571-574
We present in this paper a consistent nonparametric test for heteroscedasticity when data are of functional kind. The latter is constructed by evaluating the difference between the conditional and unconditional variances. We show the asymptotic normality of the statistical test under the null hypothesis. In addition, we prove that this test is consistent against all deviations from homoscedasticity condition. 相似文献
99.
Fernando Aguilar Fatima E.M. Alaoui José J. Segovia Miguel A. Villamañán Eduardo A. Montero 《The Journal of chemical thermodynamics》2010,42(1):28-37
Experimental excess molar enthalpies of the ternary systems {dibutyl ether (DBE) + 1-butanol + heptane} and the corresponding binary systems at T = 298.15 K and T = 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and the ternary systems show endothermic character. The experimental data for the binary and ternary systems have been fitted using the Redlich–Kister equation, the NRTL and UNIQUAC models. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations. 相似文献
100.
Multiconfiguration self-consistent field and multiconfiguration reference interaction including the Davidson’s correction techniques were employed to calculate the potential energy curves (PECs) of the BeS/BeS+ electronic states correlating to the 4/5 lowest dissociation limits. After nuclear motion treatment, we deduced reliable spectroscopic data for the neutral and cationic bound states. For BeS, the transition moments and spin-orbit couplings were also evaluated and used later with the PECs to deduce the rovibronic transition probabilities and the radiative lifetimes in the low-lying states, and to investigate the unimolecular decomposition processes of BeS (X1Σ+, A1Π, 3Σ+ and B1Σ+) leading to Be(1Sg) + S(3Pg). The prominent mechanism is a spin-orbit induced predissociation via the repulsive BeS(13Σ−) state. Finally, we give the single ionization spectrum of BeS (X1Σ+) populating the BeS+ (X2Π, 12Σ−, 12Σ+, 12Δ, 22Σ+, 22Π and 32Π) electronic states. The adiabatic ionisation energy of BeS is estimated to be ∼9.15 eV. 相似文献