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排序方式: 共有351条查询结果,搜索用时 31 毫秒
31.
All-optical logic AND-NOR gate with three inputs based on cross-gain modulation in a semiconductor optical amplifier 总被引:2,自引:0,他引:2
We report the realization of a novel all-optical logic AND-NOR gate based on cross-gain modulation (XGM). The used scheme requires only one SOA to perform the logic gate with three input signals. A 8.5 dB dynamic extinction ratio with a switching time of about 650 ps for the rise time and 100 ps for the fall time. 相似文献
32.
Labiadh Lazhar Barbucci Antonio Carpanese Maria Paola Gadri Abdellatif Ammar Salah Panizza Marco 《Journal of Solid State Electrochemistry》2017,21(8):2167-2175
Journal of Solid State Electrochemistry - In this paper, the electrocatalytic properties of PbO2 and TiRuSnO2 anodes for direct and indirect electrochemical oxidation of a synthetic solution... 相似文献
33.
Chiraz Youssef Hamed Ben Ammar Mohamed Belhouchet Kassem Beydoun Ridha Ben Salem Henri Doucet Pierre H. Dixneuf 《Journal of heterocyclic chemistry》2011,48(5):1126-1131
2‐(Arylidene)cyanomethylbenzoxazoles have been prepared in water from benzoxazole‐2‐ylacetonitriles. Using multi‐component reactions, a variety of heterocycles containing benzoxazole and nitrile functionality has been prepared. J. Heterocyclic Chem., (2011). 相似文献
34.
Y. A. Ammar A. M. Sh. El‐Sharief A. G. Al‐Sehemi Y. A. Mohamed M. A. Senussi M. S. A. El‐Gaby 《中国化学会会志》2005,52(3):553-558
Ketene dithioacetal 3 , aminopyrazole 5 , tetrazine 7 , benzoazole 9 and pyridone 11 , 12 , 13 and 16 derivatives were prepared from cyanoacetanilide 1 as a starting material. 相似文献
35.
This paper presents a theoretical formulation in which the stream-tube method (STM) is examined through a variational approach for solving solid strain and fluid flow problems with finite elements. The analysis considers a reference domain, used as computational domain, related to the physical domain by an unknown transformation function to be determined numerically. Mass conservation is automatically verified by STM. The variational approach leads to eliminate the pressure in fluid problems and avoids to set up a mixed displacement–pressure procedure in the case of incompressible solids. Examples are given for fluid flows, applications and comparisons are also provided in the bending problem in elasticity. 相似文献
36.
Summary Glass layers of (V2O5)1−x
(P2O5)
x
were prepared by melting appropriate mixtures of V2O5 and P2O5 powders. The measurements ofI–V characteristic curves show three regions of conduction, namely high-resistance state, turnover point with zero-differential
resistance region (∂V/∂I=0) and differential negative-resistance region. The turnover point is strongly dependent on composition, sample thickness
and temperature. It is found that the increase of the ratio of phosphorus/vanadium reduces conductance as well as it raises
the field required to produce turnover behaviour. The data in the range up to the turnover point are discussed on the basis
of an electrothermal process. Results of the negative-resistance state could be explained in terms of a hopping mechanism. 相似文献
37.
Elsaid Ebrahim Ammar 《Fuzzy Sets and Systems》1997,90(3):5479
This paper deals with the stability of multiobjective nonlinear programming problems with fuzzy parameters in the objectives and constraints functions. These fuzzy parameters are characterized by fuzzy numbers. The existing results concerning the qualitative analysis of the notions (solvability set, stability sets of the first kind and of the second kind) in parametric nonlinear programming problems are reformulated to study the stability of multiobjective nonlinear programming problems under the concept of α-pareto optimality. An algorithm for obtaining any subset of the parametric space which has the same corresponding α-pareto optimal solution is also presented. An illustrative example is given to clarify the obtained results. 相似文献
38.
39.
Chakroune N Viau G Ammar S Poul L Veautier D Chehimi MM Mangeney C Villain F Fiévet F 《Langmuir : the ACS journal of surfaces and colloids》2005,21(15):6788-6796
Monodisperse ruthenium nanoparticles were prepared by reduction of RuCl3 in 1,2-propanediol. The mean particle size was controlled by appropriate choice of the reduction temperature and the acetate ion concentration. Colloidal solutions in toluene were obtained by coating the metal particles with dodecanethiol. High-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XANES and EXAFS for the Ru K-absorption edge) were performed on particles of two different diameters, 2 and 4 nm, and in different environments, polyol/acetate or thiol. For particles stored in polyol/acetate XPS studies revealed superficial oxidation limited to one monolayer and a surface coating containing mostly acetate ions. Analysis of the EXAFS spectra showed both oxygen and ruthenium atoms around the ruthenium atoms with a Ru-Ru coordination number N smaller than the bulk value, as expected for fine particles. In the case of 2 nm acetate-capped particles N is consistent with particles made up of a metallic core and an oxidized monolayer. For 2 nm thiol-coated particles, a Ru-S bond was evidenced by XPS and XAS. For the 4 nm particles XANES and XPS studies showed that most of the ruthenium atoms are in the zerovalent state. Nevertheless, in both cases, when capped with thiol, the Ru-Ru coordination number inferred from EXAFS is much smaller than for particles of the same size stored in polyol. This is attributed to a structural disorganization of the particles by thiol chemisorption. HRTEM studies confirm the marked dependence of the structural properties of the ruthenium particles on their chemical environment; they show the acetate-coated particles to be single crystals, whereas the thiol-coated particles appear to be polycrystalline. 相似文献
40.
Hosny Ammar Hessian 《Journal of Russian Laser Research》2010,31(1):70-78
We study how phase decoherence through intrinsic decoherence leads to growing entropy and a strong degradation of the maximum
generated entanglement as a measure of information content of ionic state due to ion-laser interaction with a trapped ion.
We calculate the partial entropy of the particle (atom or trapped ion) and field subsystems as well as the total entropy.
The total entropy is shown to increase with time. Thus, the partial field or atomic entropy cannot be used as a direct measure
of the particle–field entanglement. We find that, at least qualitatively, the difference between the total entropy and the
sum of field and atom partial entropies can be used as an entanglement measure, when compared with an established entanglement
measure based on the negativity of the eigenvalues of the partially transposed density matrix. We find a very strong sensitivity
of the maximum generated entanglement on the decoherence and the chosen intrinsic decoherence parameter. 相似文献