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91.
Recent observation and theoretical investigations have led to the significance of electrostatic ion cyclotron (EIC) waves
in the electrodynamics of acceleration process. The instability is one of the fundamental of a current carrying magnetized
plasma. The EIC instability has the lowest threshold current among the current driven instabilities. On the basis of local
analysis where inhomogeneities like the magnetic shear and the finite width current channel, have been ignored which is prevalent
in the magnetospheric environment. On the basis of non-local analysis interesting modification has been incorporated by the
inclusion of magnetic shear. In this paper we provide an analytical approach for the non-local treatment of current driven
electrostatic waves in presence of parallel electric field. The growth rate is significantly influenced by the field aligned
electron drift. The presence of electric field enhances the growth of EIC waves while magnetic shear stabilizes the system. 相似文献
92.
We report a new unconditionally stable implicit alternating direction implicit (ADI) scheme of O(k2 + h2) for the difference solution of linear hyperbolic equation utt + 2αut + β2u = uxx + uyy + f(x, y, t), αβ ≥ 0, 0 < x, y < 1, t > 0 subject to appropriate initial and Dirichlet boundary conditions, where α > 0 and β ≥ 0 are real numbers. The resulting system of algebraic equations is solved by split method. Numerical results are provided to demonstrate the efficiency and accuracy of the method. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17: 684–688, 2001 相似文献
93.
A quantum-statistical treatment of coherert anti-Stokes Raman scatterirg in a gaseous system is presented. The atomic system is described by two energy levels. Both the atomic system and the radiation fields are quartized. The effects of atomic motion ard the detuning are incorporated into the analysis. The equations of motion describing the photor statistics of pump, Stokes and anti-Stokes fields are obtained considering the process as a two-step one. The time-evolution of average photon number and the second-order coherence of the anti-Stokes fields for different initial distributions are studied. The occurrence of antibunching is investigated. 相似文献
94.
Microwave resonance technique at 3000 MHz has been used to carry out measurements of the temperature variation of penetration depth in single crystals of pure tin. Several samples of known crystallographic orientations have been studied, and the anisotropy of penetration depth obtained. The results clearly show non-tensorial anisotropy of penetration depth, and hence provide a direct experimental evidence for non-local relation between the current density and associated magnetic field in a type I superconductor. 相似文献
95.
Bedangadas Mohanty 《Pramana》2003,60(4):613-625
Results from the photon multiplicity measurements using a fine granularity pre-shower photon multiplicity detector (PMD) at
CERN SPS are discussed. These include study of pseudorapidity distributions of photons, scaling of photon multiplicity with
number of participating nucléons, centrality dependence of 〈p
T〉 of photons, event-by-event fluctuations in photon multiplicity and localised charged-neutral fluctuations. Basic features
of the PMD to be used in STAR experiment at RHIC and in ALICE experiment at LHC are also discussed. 相似文献
96.
We employ a new fourth‐order compact finite difference formula based on arithmetic average discretization to solve the three‐dimensional nonlinear singularly perturbed elliptic partial differential equation ε(uxx + uyy + uzz) = f(x, y, z, u, ux, uy, uz), 0 < x, y, z < 1, subject to appropriate Dirichlet boundary conditions prescribed on the boundary, where ε > 0 is a small parameter. We also describe new fourth‐order methods for the estimates of (?u/?x), (?u/?y), and (?u/?z), which are quite often of interest in many physical problems. In all cases, we require only a single computational cell with 19 grid points. The proposed methods are directly applicable to solve singular problems without any modification. We solve three test problems numerically to validate the proposed derived fourth‐order methods. We compare the advantages and implementation of the proposed methods with the standard central difference approximations in the context of basic iterative methods. Numerical examples are given to verify the fourth‐order convergence rate of the methods. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2006 相似文献
97.
Bibhuti B. Samal Sagarika Sahu Braja B. Chinara S. Nanda P. K. Otta L. M. Mohapatro Trijama R. Mohanty A. R. Ray K. C. Singh 《Journal of polymer science. Part A, Polymer chemistry》1988,26(12):3159-3166
Graft copolymerization of acrylonitrile (AN) onto sisal fibers (chemically modified) was studied using the Mn(III)/EDTA redox system in aqueous solution. The effects of time, monomer (AN), metal ion [Mn(III)] substrate [ethylene diamine tetraacetic acid (EDTA)], temperature, and acid concentration on graft yield have been studied. The effects of thiourea on the graft yield has also been studied. A suitable mechanism is proposed. 相似文献
98.
Raj Gandhi Subhendra Mohanty Tarun Souradeep S Agarwalla K Bhattacharya B Brahmachari R Crittenden S Goswami P Ghoshal M Lindner H S Mani S Mitra S Pascoli S Panda R Rangarajan S Ray T Roy Choudhury R Saha S Sarkar A Srivastava R Sheth S Uma Sankar U Yajnik 《Pramana》2006,67(4):735-742
The working group on astroparticle and neutrino physics at WHEPP-9 covered a wide range of topics. The main topics were neutrino
physics at INO, neutrino astronomy and recent constraints on dark energy coming from cosmological observations of large scale
structure and CMB anisotropy. 相似文献
99.
A simple method for obtaining lateral shear using holo shear lenses (HSL) has been discussed. This simple device which produces lateral shears in the orthogonal directions has been used for lens testing. The holo shear lens is placed at or near the focus of the lens to be tested. It has also been shown that HSL can be used in speckle shear interferometry as it performs both the functions of shearing and imaging. 相似文献
100.
The method of optical model analysis of generalized elastic scattering angular distributions (GESA) has been applied to heavy
ion scattering to derive fusion spin distributions. This method is used to reproduce the coupled channel fusion spin distributions.
When applied to experimental data, particularly to the fissile systems like16O +232Th, the method gives large mean square spin values in agreement with “anomalous” values derived from experimental fission
fragment anisotropies. 相似文献