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51.
Zakaria Benzekri Sara Sibous Houda Serrar Ali Ouasri Said Boukhris Ali Rhandour Abdelaziz Souizi 《Journal of the Iranian Chemical Society》2018,15(12):2781-2787
In this work, the condensation of aromatic aldehydes with different two-substituted aniline catalyzed by NH3(CH2)5NH3BiCl5 as heterogeneous and recyclable catalyst was reported. It was demonstrated that NH3(CH2)5NH3BiCl5 can act as an efficient and active catalyst and is reusable for six runs without a significant loss of their catalytic activity. Simple preparation of the catalyst, high catalytic activity and good reusability are noteworthy advantages of this catalytic system in the synthesis of benzoxazole, benzimidazole and benzothiazole heterocycles at room temperature under solvent-free conditions. 相似文献
52.
Nonlinear Dynamics - The transfer of advanced technology to the person with a disability who wishes to practice a sporting activity is gaining momentum in the science/engineering world. This paper... 相似文献
53.
Coherent states for power-law potentials are constructed using generalized Heisenberg algebra. Klauder's minimal set of conditions required to obtain coherent states are satisfied. The statistical properties of these states are investigated through the evaluation of the Mandel's parameter. It is shown that these coherent states are useful for describing the states of real and ideal lasers. 相似文献
54.
S. Abdel-Khalek K. Berrada Y. S. El-Saman M. Abdel-Aty 《Journal of Russian Laser Research》2012,33(5):437-447
We study the time evolution of the total and Pancharatnam phase of four-level atoms in the presence of a one-dimensional photonic-band-gap material. We obtain analytical and numerical results under certain parametric conditions and analyze the effect of a Kerr-like medium and the detuning parameter on the dynamics of the Pancharatnam phase for the initial atomic position. We observe an interesting feature of the Pancharatnam phase for the one-dimensional photonic-band-gap material. 相似文献
55.
Sloshing behavior of a magnetic fluid in a cylindrical container 总被引:1,自引:0,他引:1
Sloshing of a magnetic fluid in a laterally vibrated cylindrical container subject to a non-uniform vertical magnetic field
was examined. Internal velocity profiles were measured using ultrasound Doppler velocimetry. The effect of the magnetic field
on the resonant frequency of the fluid–container system was examined and the results were compared with theoretical results.
The second and third peaks of the power spectra of velocity shifted to lower frequencies as the magnetic field was increased.
It was observed that these derived frequency peaks were connected with swirling in the cylindrical container.
Received: 9 May 2000 / Accepted: 29 May 2001 Published online: 29 November 2001 相似文献
56.
Betz T Manz S Bücker R Berrada T Koller Ch Kazakov G Mazets IE Stimming HP Perrin A Schumm T Schmiedmayer J 《Physical review letters》2011,106(2):020407
We realize a one-dimensional Josephson junction using quantum degenerate Bose gases in a tunable double well potential on an atom chip. Matter wave interferometry gives direct access to the relative phase field, which reflects the interplay of thermally driven fluctuations and phase locking due to tunneling. The thermal equilibrium state is characterized by probing the full statistical distribution function of the two-point phase correlation. Comparison to a stochastic model allows us to measure the coupling strength and temperature and hence a full characterization of the system. 相似文献
57.
58.
We propose a relaxation rate or dissipative cavity-based parameters that can be used as indicators of the stationary limit of a mixed state geometric phase. We perform our considerations for the system of a superconducting qubit in an open transmission line or interacting with a dissipative cavity. This system is very useful for performing an effective quantum computation by exhibiting the long collapse time of the geometric phase. It is shown that the geometric phase in the stationary limit does not depend on interaction time if the decay time exceeds an upper bound. 相似文献
59.
Reda M. El-Shishtawy K. Berrada Robert C. Haddon Yas F. Al-Hadeethi Saleh. H. Al-Heniti Bahaaudin M. Raffah 《International Journal of Theoretical Physics》2017,56(5):1417-1428
The presence of coherence phenomenon due to the interference of probability amplitude terms, is one of the most important features of quantum mechanics theory. Recent experiments show the presence of quantum processes whose coherence provided over suddenly large interval-time. In particular, photosynthetic mechanisms in light-harvesting complexes provide oscillatory behaviors in quantum mechanics due to quantum coherence. In this work, we investigate the coherent quantum transfer energy for a single-excitation and nonlocal correlation in a dimer system modelled by a two-level atom system with and without time-dependent coupling effect. We analyze and explore the required conditions that are feasible with real experimental realization for optimal transfer of quantum energy and generation of nonlocal quantum correlation. We show that the enhancement of the probability for a single-excitation transfer energy is greatly benefits from the combination of the energy detuning and time-dependent coupling effect. We investigate the presence of quantum correlations in the dimer using the entanglement of formation. We also find that the entanglement between the donor and acceptor is very sensitive to the physical parameters and it can be generated during the coherent energy transfer. On the other hand, we study the dynamical behavior of the quantum variance when performing a measurement on an observable of the density matrix operator. Finally, an interesting relationship between the transfer probability, entanglement and quantum variance is explored during the time evolution in terms of the physical parameters. 相似文献
60.
In this paper, we develop a model for four-level double Raman pairs by exploiting the required optimal conditions for this system that are feasible with real experimental realization. We investigate qualitatively the entanglement, statistical properties, and geometric phase for the pair of Stokes and anti-Stokes photons in the presence of the relativistic motion. We show that these quantifiers are very sensitive to the change of the Rabi frequency under relativistic motion, exhibiting substantial phenomena that depend on this kind of the coupling between the atom and photons. Finally, we explore the relationship between the quantum quantifiers for constant and time-dependent coupling. 相似文献