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731.
Spatially homogeneous and anisotropic LRS Bianchi type-I metric is considered in the framework of Nordtvedt-Barker’s general
scalar-tensor theory of gravitation when the source for the energy momentum tensor is a perfect fluid. With the help of a
special law of variation for Hubble’s parameter proposed by Berman (Nuovo Cim. B. 74:182, 1983) a cosmological model with negative constant deceleration parameter is obtained. Some physical and kinematical properties
of the model are also discussed. 相似文献
732.
Karunakaran C Jayabharathi J Brindha Devi K Jayamoorthy K 《Journal of fluorescence》2012,22(4):1047-1053
A sensitive imidazole based fluorescent sensor like 4, 5-diphenyl-2(E)-styryl-1H-imidazole, for ZnO has been designed and synthesized via simple steps. The absorption, fluorescence, SEM, EDX and IR studies indicate that imidazole derivative is bound on the surface of ZnO semiconductor. Based on photo-induced electron transfer (PET) mechanism, fluorescent enhancement has been explained and apparent binding constant has been calculated. Ligand adsorption on ZnO nanoparticle lowers of the HOMO and LUMO energy levels of imidazole derivative and the chemical affinity between the nitrogen atom of the imidazole and zinc ion on the surface of the nano oxide may be a reason for strong adsorption of the ligand on nanoparticle. The electron injection from photo excited imidazole derivative to the ZnO conduction band (S(*)→S(+) + e (CB) (-) ) accounts for the enhanced fluorescence. 相似文献
733.
We report magnetization, dielectric and dc transport properties of La(2)NiMnO(6) nanoparticles. Both dc and ac magnetization measurements indicated a metastable magnetic behaviour with random ferromagnetic and antiferromagnetic interactions below 110 K; critical slow-down, memory and rejuvenation properties signify the spin glass nature. The dc resistivity shows a semiconducting nature but the temperature dependent magnetoresistance (MR) shows a peak at the spin glass transition. The colossal dielectric property and its frequency dependence were interpreted using the Maxwell-Wagner (MW) interfacial polarization model. Impedance analysis along with magnetodielectric (MD) and magnetoresistance (MR) indicates that the observed MD originates from the combined effect of MR and MW interfacial polarization. 相似文献
734.
Ch. Nagarjun Rao K. C. Rajanna Y. Uma Devi V. Surender Rao P. K. Saiprakash 《Journal of Chemical Sciences》1988,100(4):329-335
The stability constants of some tervalent lanthanide chelates of 1-(3-aryl-5-hydroxy 4-isoxazolylazo) 4-sulphonic acid (PHI-4S)
and its substituents have been carried out by potentiometric and spectrophotometric methods. The results indicated the formation
of 1:1 and 1:2 complexes with an order: Yb(III) > Y(III) > Gd(III) > Dy(III) > Tb(III) > Sm(III) > Nd(III) > Pr(III) > La(III).
The stabilities increase with a decrease in the ionic or crystal radii [except a small break at Gd(III)], indicates the absence
of extensive covalent bonding due to the non-availability of 4f-orbitals for bond formation. Structure-reactivity relationships
of complex formation have been discussed by Hammett’s and Irving-Rossotti theories. Thermodynamic parameters have been discussed
in terms of iso-equilibrium relationship. 相似文献
735.
V Malathy Devi B Fridovich G.D Jones D.G.S Snyder 《Journal of Molecular Spectroscopy》1984,105(1):61-69
Absolute line strengths have been measured at room temperature for spectral lines in the R branch of the ν3 band of 12C16O2, 12C16O18O, and 12C16O17O and the (ν2 + ν3) ? ν2 and (ν1 + ν3) ? ν1 bands of 12C16O2 in the region 2365–2393 cm?1 using a tunable diode laser spectrometer; from these measurements band strengths have been computed. Self- and nitrogen-broadened half-widths have been measured for some ν3 lines of 12C16O2 and 12C16O17O, and nitrogen-broadened half-widths measured for some (ν2 + ν3) ? ν2 band lines of 12C16O2. From measurements made over a temperature range from 217 to 299 K we have obtained temperature coefficients n, for the N2-broadened Lorentz half-width defined as , for the ν3 and (ν2 + ν3) ? ν2 bands of 12C16O2. They are 0.757 ± 0.008 and 0.789 ± 0.015, respectively. 相似文献
736.
?. Urban D. Papou?ek V. Malathy Devi B. Fridovich Romola DCunha K. Narahari Rao 《Journal of Molecular Spectroscopy》1984,106(1):38-55
Line intensities as well as self- and nitrogen-broadening coefficients have been determined for 20 transitions in the 2ν2 and ν4 bands of 14NH3 using a diode laser spectrometer. Vibrational-inversional transition moments have been determined for transitions from the ground state to the ν2, 2ν2 and ν4 states by a least-squares fit to the line intensities, taking into account Coriolis and l-type interactions between the nν2 (n = 1, 2, 3), ν4 and ν2 + ν4 states [?. Urban, V. ?pirko, D. Papou?ek, R. S. McDowell, N. G. Nereson, S. P. Belov, L. I. Gershtein, A. V. Maslovskij, A. F. Krupnov, J. Curtis, and K. Narahari Rao, J. Mol. Spectrosc.79, 455–495 (1980)]. The values of these transition moments have been combined with the previously obtained transition moments for NH3 and its isotopomers to obtain an improved fit to the μz component of the electric dipole moment function of ammonia [cf. V. ?pirko, J. Mol. Spectrosc.74, 456–464 (1979)]. 相似文献
737.
738.
The yrast spectra, intrinsic quadrupole moments and root mean square radii for each angular momentum state, calculated for 108–112Ru isotopes by carrying out Cranked-Hartree-Fock-Bogoliubov (CHFB) calculations. These calculations have been performed by employing pairing-plus-quadrupole-quadrupole effective interaction operating in a reasonably large valence space outside 76Sr core. The experimentally available spectra upto 10+ is reasonably well reproduced. Our results indicate that there is a possibility for observing backbending phenomenon in 108,110,112ru at spins 12 +, 20+ and 14+, respectively, which remains yet to be confirmed experimentally. 相似文献
739.
V Malathy Devi B Fridovich G.D Jones D.G.S Snyder 《Journal of Molecular Spectroscopy》1983,97(2):333-342
Line strengths and self- and nitrogen-broadened half-widths were measured for spectral lines in the ν3 and ν2 + ν4 bands of 12CH4 and 13CH4 from 2870–2883 cm?1 using a tunable diode laser spectrometer. From measurements made over a temperature range from 215 to 297 K, on samples of 12CH4 broadened with N2, we deduced that the average temperature coefficients n, defined as , of the Lorentz broadening coefficients for the ν3 and ν2 + ν4 bands of 12CH4 were 0.97 ± 0.03 and 0.89 ± 0.04, respectively. A smaller increase is observed in line half-width with increasing pressure for E-species lines, for both self- and nitrogen-broadening, than for other symmetry species lines over the range of pressures measured, 70 to 100 Torr. 相似文献
740.
Koji Ishizu Usha Devi G. Prabhu Dan Draney Byung H. Lee C. S. Marvel 《Journal of polymer science. Part A, Polymer chemistry》1982,20(10):2851-2862
A series of acetylene-terminated quinoxaline oligomers was synthesized for testing as possible adhesives for airplane manufacturing. 相似文献