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81.
Kishor S. Adhav Abhijit S. Bansod Rajesh P. Wankhade Hanumant G. Ajmire 《Central European Journal of Physics》2011,9(4):919-925
The exact solutions of the Einstein field equations for dark energy in Kantowski-Sachs metric under the assumption on the
anisotropy of the fluid are obtained for exponential and power-law volumetric expansions. The isotropy of the fluid, space
and expansion are examined. 相似文献
82.
We present a method for stabilizing ferromagnetism in Mn doped ZnO. We find that Mn doped ZnO show anti-ferromagnetic order in the absence of additional carriers. When Mn doped ZnO is co-doped with C atom at O sites ferromagnetic state gets stabilized. The C doping creates holes which leads to stabilization of ferromagnetic state via hole mediated double exchange mechanism. 相似文献
83.
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85.
V.K. Sharma S. Mitra P. Maheshwari D. Dutta P.K. Pujari R. Mukhopadhyay 《The European physical journal. Special topics》2010,189(1):273-277
Dynamics of ethylene glycol (EG) adsorbed in H-ZSM5 zeolite as studied using quasielastic neutron scattering (QENS) technique
is reported here. Analysis of QENS data revealed that observed dynamics correspond to isotropic rotational motion of EG. Rotational
diffusion coefficient of EG adsorbed in H-ZSM5 zeolite is found to be slower compared to bulk and comparable to that of benzene
adsorbed in the same host. Positron Annihilation Spectroscopy (PAS) technique is used to understand the nature of guest-host
interaction and the results of both QENS and PAS are found to be consistent with each other. 相似文献
86.
This article illustrates the developments of effective preconcentration techniques and highly sensitive detection methods for accurate measurements of Tl species at extremely low concentration in aqueous solutions. The literature on this topic was taken from the Analytical Abstracts in the period 1990-2005. 相似文献
87.
The amount and extent of structural misaligments in natural graphite crystals have been determined, and the temperature variation of the basal plane electrical conductivity (σ⊥) of naturally occurring graphite has also been studied from 300 to 90 K. The conductivity (σ⊥) has been found to obey a law σ⊥α() down to a certain temperature θ (θ varying from sample to sample), below which the variation deviates from linearity towards lower values of σ⊥. This behaviour, which was earlier thought to be a characteristic of graphite and whose origin could not be traced, has been shown to be an effect of the structural misalignments usually present in natural samples of graphite. 相似文献
88.
By applying ultrasound at different frequencies and intensities through the bottom of a narrow tube containing liquids of varying physical properties, followed by critical analysis of the experimental data, a systematic study of the effect of these parameters on enhancement in rate of mass transfer has been made and a correlation has been proposed for prediction of such enhancement. 相似文献
89.
An integral approach to phase measurement is presented. First, the use of a high-resolution technique for the pixelwise detection of phase steps is proposed. Next, the robustness of the algorithm that is developed is improved by incorporation of a denoising procedure during spectral estimation. The pixelwise knowledge of phase steps is then applied to the Vandermonde system of equations for retrieval of phase values at each pixel point. Conceptually, our proposal involves the design of an annihilating filter that has zeros at the frequencies associated with the polynomial that describes the fringe intensity. The parametric estimation of this annihilating filter yields the desired spectral information embedded in the signal, which in our case represents the phase steps. The proposed method offers the advantage of extracting the interference phase of nonsinusoidal waveforms in the presence of miscalibration error of the piezoelectric transducer. In addition, in contrast to previously reported methods, this method does not require the application of selective phase steps between data frames for nonsinusoidal waveforms. 相似文献
90.
A maximum-likelihood (ML) method based on spectral estimation theory for the extraction of dual phase distributions in holographic moire in the presence of nonsinusoidal waveforms, noise, and the miscalibration of piezoelectric (PZT) devices is proposed. The extraction of these phases requires incorporating two PZTs into the moire setup. ML estimators are asymptotically efficient for sufficient data samples. The approach presented uses a direct stochastic algorithm called probabilistic global search Lausanne for minimizing the ML function. 相似文献