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91.
Kumar S 《Optics letters》2007,32(4):346-348
It is shown that the third-order dispersion of an optical fiber can be compensated for using a time-reversal system that can be implemented with periodic time lenses. 相似文献
92.
Shiva Agarwal M. Teresa A. Reis M. Rosinda C. Ismael Jorge M. R. Carvalho 《Chemical Papers》2015,69(5):679-689
The extraction of copper from sulphuric/sulphate solutions using a hollow fibre module as contactor was studied. The aldoxime Acorga M5640 was used as an extractant. The effects on the extraction rate of the flow-rates, the concentrations of copper and extractant, pH, and the presence of Na2SO4 in the feed phase were investigated. The overall mass transfer coefficient for copper extraction was calculated from the experimental data and was compared with the value evaluated by the resistance in the series model. The extraction process was found to be governed by the diffusion in the boundary aqueous layer and also by the chemical reaction. The kinetic data obtained were used to simulate the extraction of copper with the pseudo-emulsion-based hollow fibre with strip dispersion technique. The accordance between the results thus calculated and the experimental data was found to be satisfactory, particularly for dilute feed solutions. 相似文献
93.
Shiva Konda Kiran M. S. R. N. Ramamurty U. Asokan S. Bhattacharyya Aninda J. 《Journal of Solid State Electrochemistry》2012,16(11):3643-3649
Journal of Solid State Electrochemistry - We demonstrate here that mesoporous tin dioxide (abbreviated M-SnO2) with a broad pore size distribution can be a prospective anode in lithium-ion... 相似文献
94.
Kumar KS Rambabu D Prasad B Mujahid M Krishna GR Rao MV Reddy CM Vanaja GR Kalle AM Pal M 《Organic & biomolecular chemistry》2012,10(24):4774-4781
Regioselective construction of a fused 2-ylidene chromene ring was achieved for the first time by using AlCl(3)-induced C-C bond formation followed by Pd/C-Cu mediate coupling-cyclization strategy. A number of chromeno[4,3-b]quinoxaline derivatives were prepared by using this strategy. Single crystal X-ray diffraction study of a representative compound e.g. 6-(2,2-dimethylpropylidene)-4-methyl-6H-chromeno[4,3-b]quinoxalin-3-ol confirmed the presence of an exocyclic C-C double bond with Z-geometry. The crystal structure analysis and hydrogen bonding patterns of the same compound along with its structure elaboration via propargylation followed by Sonogashira coupling of the resulting terminal alkyne is presented. A probable mechanism for the formation of 2-ylidene chromene ring is discussed. Some of the compounds synthesized showed anticancer properties when tested in vitro. 相似文献
95.
The magnetic and magnetocaloric properties of polycrystalline La0.70(Ca0.30−xSrx)MnO3:Ag 10% manganite have been investigated. All compositions are crystallized in single phase orthorhombic Pbnm space group. Both, the insulator–metal transition temperature (TIM) and Curie temperature (Tc) are observed at 298 K for x=0.10 composition. Though both TIM and Tc are nearly unchanged with Ag addition, the MR is increased. The MR at 300 K is found to be as large as 31% with magnetic field change of 1 T, whereas it reaches up to 49% at magnetic field of 3 T for the La0.70Ca0.20Sr0.10MnO3:Ag0.10 sample. The maximum entropy change (ΔSMmax) at near its Tc (300.5 K) is 7.6 J kg−1 K−1 upon the magnetic field change of 5 T. The La0.70Ca0.20Sr0.10MnO3:Ag0.10 sample having good MR (31%1 T, 49%3 T) and reasonable change in magnetic entropy (7.6 J kg−1.K−1, 5 T) at 300 K can be a potential magnetic refrigerant material at ambient temperatures. 相似文献
96.
A. M. Msomi K. S. Govinder S. D. Maharaj 《International Journal of Theoretical Physics》2012,51(4):1290-1299
We consider a radiating shear-free spherically symmetric metric in higher dimensions. Several new solutions to the Einstein’s
equations are found systematically using the method of Lie analysis of differential equations. Using the five Lie point symmetries
of the fundamental field equation, we obtain either an implicit solution or we can reduce the governing equations to a Riccati
equation. We show that known solutions of the Einstein equations can produce infinite families of new solutions. Earlier results
in four dimensions are shown to be special cases of our generalised results. 相似文献
97.
Murtaza Bohra Shiva Prasad N. Venketaramani Naresh Kumar S.C. Sahoo R. Krishnan 《Journal of magnetism and magnetic materials》2009,321(22):3738-3741
Temperature dependence of the magnetic properties of magnetite thin film across the Verwey transition has been investigated. As the temperature is decreased, the magnetization of the film in a fixed field showed a sharp decrease close to the Verwey transition temperature (Tv). The M–H loops of the film have been recorded at various temperatures below and above Tv. It is found that film does not saturate at any temperature and saturation becomes more difficult below Tv. While cooling through Tv, the extrapolated value of magnetization to infinite field (Q), calculated from the numerical fit 4πM=Q [1−(H*/H)1/2], does not show a drop, but the coefficient indicating difficulty in saturation (H*) shows a sharp rise as does the coercivity. 相似文献
98.
Naresh Kumar Shiva Prasad D.S. Misra N. Venkataramani Murtaza Bohra R. Krishnan 《Journal of magnetism and magnetic materials》2008
Yttrium iron garnet (YIG) thin films were deposited on fused quartz substrate at different substrate temperatures (Ts) varying from room temperature (RT) to 850 °C using pulsed laser deposition (PLD) technique. All the films in the as-deposited state were X-ray amorphous and non-magnetic at RT. The film deposited at RT after annealing at temperatures Ta?700 °C showed both X-ray peaks and the magnetic order. The films deposited at higher Ts (500–850 °C) and then annealed at 700 °C resulted in better-quality films with higher 4πMs value. The highest value of magnetization was for the sample deposited at 850 °C and annealed at 700 °C, which is 68% of the bulk 4πMs value. 相似文献
99.
The equation is the charged generalization of the Emden-Fowler equation that is crucial in the study of spherically symmetric shear-free spacetimes. This version arises from the Einstein–Maxwell system for a charged shear-free matter distribution. We integrate this equation and find a new first integral. For this solution to exist, two integral equations arise as integrability conditions. The integrability conditions can be transformed to nonlinear differential equations, which give explicit forms for and in terms of elementary and special functions. The explicit forms and arise as repeated roots of a fourth order polynomial. This is a new solution to the Einstein-Maxwell equations. Our result complements earlier work in neutral and charged matter showing that the complexity of a charged self-gravitating fluid is connected to the existence of a first integral. 相似文献