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排序方式: 共有298条查询结果,搜索用时 15 毫秒
21.
The problem of the interaction between two quantum systems namely SU(1,1) and SU(2) is considered. Using the evolution operator technique, an exact solution of the wave function and consequently the density matrix are obtained. The entropy squeezing is examined and it has shown that, different values of the relative phase angle ? as well as the coupling parameter λ lead to different observation of the squeezing in the quadratures. In the meantime, we have shown that the entropy squeezing is also sensitive to the variation in the state angle θ, the detuning parameter Δ in addition to the excitation number m. Moreover, for a large value of the detuning parameter there is a weak entanglement between the atom and the quantum system and vice versa. Furthermore, we find that the Q-function is sensitive to the variation in the excitation number m in addition to the Bargmann index k where the nonclassical effect is pronounced for the even parity. 相似文献
22.
S. Abdalla 《Physica B: Condensed Matter》2011,406(3):584-587
The complicated structure of human blood has been characterized based on relaxation time, τ, and the Cole-Cole parameter, α, obtained from dielectric measurements. As previously reported by different authors, the experimental data show net deviation from the classical Debye model with certain distribution of relaxation times (Dτ). Plots of α versus width of the relaxation rate distribution of micro-particles inside the blood show that Dτ drastically affects the dielectric properties of the fluid. The mathematical function of Dτ is found to be Gaussian and we find that the α values of normal blood have net lower magnitude than that of diabetic blood. These results suggest that glucose in blood increases the broadness of the parameter α, which have significant importance in diabetic-biosensor manufacture. 相似文献
23.
N. Metwally M. Sebawe Abdalla M. Abdel-Aty 《International Journal of Theoretical Physics》2010,49(9):2051-2064
The present paper is devoted to consider the problem of the interaction between a pair of entangled qubits and a multiphotons
cavity mode. The deformed operators are involved in the Hamiltonian model which represents such system. The exact solution
of the wave function is obtained and the density matrix is contracted. For two different types of Bell states, the purity
as well as the fidelity of the system are investigated. In our computational program we have used different values of the
photon numbers and the deformity parameter to investigate the robustness of these entangled states. It is shown that, for
small values of the deformity parameter the purity and the fidelity of the travel state are improved. On the other hand, in
the absence of the deformation parameter the number of photons inside the cavity improve the stability behavior for the purity
and the fidelity. 相似文献
24.
A model of a single atom interacting with isotropic two modes pumped simultaneously within a perfect cavity is examined. The quantum fidelity is employed to measure the quality of transmitted information as a function of the input state. The behavior of the quantum fidelity is studied at off-resonances between the atom and fields for different preparations of initial states. 相似文献
25.
E. Abdalla M. C. B. Abdalla J. C. Brunelli A. Zadra 《Communications in Mathematical Physics》1994,166(2):379-396
We obtain the exact classical algebra obeyed by the conserved non-local charges in bosonic non-linear sigma models. Part of the computation is specialized for a symmetry groupO(N). As it turns out the algebra corresponds to a cubic deformation of the Kac-Moody algebra. We generalize the results for the presence of a Wess-Zumino term. The algebra is very similar to the previous one, now containing a calculable correction of order one unit lower. The relation with Yangians and the role of the results in the context of Lie-Poisson algebras are also discussed.Supported by FAPESP.Supported by CNPq.Supported by CNPq 相似文献
26.
Cooperative Bond Activation and Catalytic Reduction of Carbon Dioxide at a Group 13 Metal Center 下载免费PDF全文
Joseph A. B. Abdalla Dr. Ian M. Riddlestone Rémi Tirfoin Prof. Simon Aldridge 《Angewandte Chemie (International ed. in English)》2015,54(17):5098-5102
A single‐component ambiphilic system capable of the cooperative activation of protic, hydridic and apolar H? X bonds across a Group 13 metal/activated β‐diketiminato (Nacnac) ligand framework is reported. The hydride complex derived from the activation of H2 is shown to be a competent catalyst for the highly selective reduction of CO2 to a methanol derivative. To our knowledge, this process represents the first example of a reduction process of this type catalyzed by a molecular gallium complex. 相似文献
27.
Mohamed Abdalla Darwish Sotiris K. Ntouyas 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(11):3510-3517
We study the existence of monotonic solutions of a quadratic fractional Hammerstein-Volterra integral equation with linear modification of the argument. The quadratic integral equation studied below contains as a special case numerous integral equations encountered in the theory of radiative transfer and in the kinetic theory of gases. We show that the quadratic fractional Hammerstein-Volterra integral equation with linear modification of the argument has a monotonic solution in the Banach space of all real functions defined and continuous on a bounded and closed interval. The concept of measure of noncompactness and a fixed point theorem due to Darbo are the main tools in carrying out our proof. 相似文献
28.
Using capillary electrophoresis (CE) three chiral primary amine compounds 1-aminoindan (AI), 1-(1-naphthyl)ethylamine (NEA) and 1,2,3,4-tetrahydro-1-naphthylamine (THAN), exhibited only partial or no separation when β-cyclodextrin (βCD) was used as chiral selector. The use of 18-crown-6 (18C6) as a second additive with βCD resulted in an enhanced separation. A molecular modeling study, using molecular mechanics and the semiempirical PM6 calculations, was used to help explaining the mechanism of the enantiodifferentiation and to predict the separation process. Optimization of the structures of the complexes by the PM6 method indicate that the poor separation obtained in the presence of the βCD chiral selector alone is due to the small binding energy differences (ΔΔE) of 4.7, 1.1 and 1.2 kcal mol(-1) for AI, NEA and THAN, respectively. In the presence of 18C6 it was suggested that a sandwich compound between 18C6, amine and βCD is formed. Theoretical calculations show that a significant increase in the binding energy is obtained for the sandwich compounds indicating strong hydrophobic and van der Waals interactions that show enhanced enantiodifferentiation. 相似文献
29.
30.
Zinad DS Shaaban KA Abdalla MA Islam MT Schüffler A Laatsch H 《Natural product communications》2011,6(1):45-48
Four isocoumarins have been isolated from the terrestrial Streptomyces sp. ANK302, namely 6,8-dimethoxy-3-methylisocoumarin (1), 6,8-dihydroxy-3-methylisocoumarin (2), 6,8-dihydroxy-7-methoxy-3-methylisocoumarin (3), and 6,7,8-trimethoxy-3-methylisocoumarin (4). Compound 1 is a new naturally-occurring isocoumarin, and 2 was isolated as a new bacterial product. The structures 1-4 were deduced from high resolution mass, 1D and 2D NMR spectra and by comparison with related compounds from the literature. Compound 2 showed a strong zoosporicidal activity at a concentration of 5 microg/mL against a phytopathogenic oomycete, Plasmopara viticola, and 1 was active against 相似文献