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671.
Twenty 2,3‐disubstituted‐4(3H)‐quinazolinones were synthesed by one‐pot three‐component method with isatoic anhydride, orthoesters and amines as raw materials in the presence of KAl(SO4)2·12H2O (Alum) under microwave irradiation and solvent‐free conditions. 6‐Bromo‐2‐propyl‐3‐p‐tolylquinazolin‐4(3H)‐one ( 4m ), 6‐bromo‐2‐methyl‐3‐phenethylquinazolin‐4(3H)‐one ( 4n ) and 6‐bromo‐2‐ethyl‐3‐phenethylquinazolin‐4(3H)‐one ( 4o ) were characterized by IR, 1H NMR, 13C NMR and elemental analysis. 相似文献
672.
M. Mohammadi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,62(2):255-260
The temporal evolution of both the atomic population inversion of an effective two-level atom and the cross correlation between
the two modes in two-photon Jaynes-Cummings model in the presence of a classical homogeneous gravitational field are investigated.
To analyse the dynamical evolution of the atom-radiation system a quantum treatment of the internal and external dynamics
of the atom is presented based on an alternative su(2) dynamical algebraic structure. By solving the Schr?dinger equation
in the interaction picture, the evolving state of the system is found by which the influence of the gravitational field on
the dynamical behavior of both the atomic population inversion of an effective two-level atom and the cross correlation between
the two modes of the radiation field are explored. Assuming that initially the radiation field is prepared in the coherent
state for each mode and an effective two-level atom is in a coherent superposition of the excited and ground states, the influence
of gravity on both the atomic population inversion of an effective two-level atom and the cross correlation between the two
modes of the radiation field are studied. 相似文献
673.
M. Mohammadi M. H. Naderi M. Soltanolkotabi 《International Journal of Theoretical Physics》2008,47(4):983-1004
In this paper, we study the dissipative dynamics of the phase damped Jaynes–Cummings model under the Markovian approximation
in the presence of a classical homogeneous gravitational field. The model consists of a moving two-level atom simultaneously
exposed to the gravitational field and a single-mode traveling radiation field in the presence of a phase damping mechanism.
We first present the master equation for the reduced density operator of the system under the Markovian approximation in terms
of a Hamiltonian describing the atom-field interaction in the presence of a homogeneous gravitational field. Then, by making
use of the super-operator technique, we obtain an exact solution of the master equation. Assuming that initially the radiation
field is prepared in a Glauber coherent state and the two-level atom is in the excited state, we investigate the influence
of gravity on the temporal evolution of collapses and revivals of the atomic population inversion, atomic dipole squeezing,
atomic momentum diffusion, photon counting statistics and quadrature squeezing of the radiation field in the presence of phase
damping. 相似文献
674.
F. Kheirandish S. J. Akhtarshenas H. Mohammadi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(1):129-140
Entanglement dynamics of an open two-qubit anisotropic
XY Heisenberg system is investigated in the presence of an
inhomogeneous magnetic field and spin-orbit interaction. We
suppose that each qubit interacts with a separate thermal
reservoir which is held in its own temperature. The asymptotical
and the dynamical behavior of entanglement are analyzed. To
distinguish between entanglement induced by the environment and
entanglement due to the presence of inter-qubit interaction, the
effects of spin-orbit parameter D and temperature difference
parameter ΔT on the entanglement of the system have been
investigated. We show that for a fixed set of the system
parameters, entanglement can be produced just by adjusting the
temperature difference between the reservoirs. The size of this
entanglement, which is induced by temperature difference of
reservoirs, increases as the spin-orbit parameter D increases.
Also we find that, this environment induced entanglement can be
improved if the qubit influenced by the weaker magnetic field is
in contact with the hotter reservoir, i.e. indirect geometry of
connection. In this case, the amount of asymptotic entanglement
increases as D increases. Regardless of the geometry of
connection, increasing D causes the appearance of entanglement
in the larger regions of TM-ΔT plane, therefore
entanglement can exist in higher temperatures and temperature
differences. Furthermore, increasing D enhances the amount of
entanglement in these regions. We also show that the state of the
system can be found in the maximally entangled state for the case
of zero temperature reservoirs and large amount of the spin-orbit
parameter. 相似文献
675.
Phase formation and change of magnetic properties in mechanical alloyed Ni0.5Co0.5Fe2O4 by annealing
Amin Azizi H. Yoozbashizadeh M. Mohammadi 《Journal of magnetism and magnetic materials》2010,322(1):56-1520
The effects of milling time and annealing temperature on phase formation, microstructure and magnetic properties of nickel-cobalt ferrite synthesized from oxide precursors by mechanical alloying were studied. The study of milling time effects on phase formation of milled materials showed that if milling continues up to 55 h, single phase nano-sized nickel-cobalt ferrite is obtained. Also, magnetic properties of powders versus milling time and annealing at different temperatures extensively changed, so that annealing at 1200 °C increased the magnetization saturation of the as-milled powder from 15.1 to 53.6 emu/g. X-ray powder diffraction technique (XRD) with Cu-Ka radiation was employed for phase identification. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were also used to determine the morphology and size of the particles. The magnetic properties were measured by a vibration sample magnetometer (VSM). 相似文献
676.
677.
Antibacterial fibers have great potential in numerous applications, including bandages, surgical robes, and surgical sutures, and play a significant role in our everyday lives. Here, zeolitic imidazolate framework-67 was synthesized using a green method on silk fibers through a layer-by-layer process under ultrasonic irradiation (ZIF-67@silk [U]) and without ultrasonic irradiation (ZIF-67@silk [B]). Then, iodine was loaded on ZIF-67@silk samples and were assessed as antibacterial fibers with iodine release. Four samples of ZIF-67@silk and I2@ZIF-67@silk were characterized by FT-IR, PXRD, FE-SEM, TGA, BET, and UV–Vis spectroscopy. Finally, antibacterial activity of ZIF-67@silk (B and U) and I2@ZIF-67@silk (B and U) on Staphylococcus aureus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria was investigated. In addition to ZIF-67@silk samples, iodine-loaded samples showed excellent antimicrobial facility. 相似文献
678.