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991.
利用半经典方法研究了平行电磁场中里德堡氢原子的分形自相似现象. 通过研究平行电磁场中里德堡氢原子的逃逸时间和初始出射角间的关系, 发现了逃逸时间图的自相似结构, 并通过研究与图中冰柱对应的逃逸轨道, 得到了自相似结构和逃逸轨道之间的关系, 发现了该类自相似逃逸轨道满足的规律. 进一步研究了标度能量和标度磁场对体系动力学的影响, 表明标度能量和标度磁场均控制体系的分形自相似结构. 当标度能量或标度磁场比较小时, 没有自相似现象, 随着标度能量或标度磁场的增大, 自相似出现, 体系变复杂. 相似文献
992.
Juan J Torres-Vega Alejandro Vásquez-Espinal Dr. Lina Ruiz Prof. María A Fernández-Herrera Prof. Luis Alvarez-Thon Prof. Gabriel Merino Prof. William Tiznado 《ChemistryOpen》2015,4(3):302-307
The electron delocalization of benzene (C6H6) and hexafluorobenzene (C6F6) was analyzed in terms of the induced magnetic field, nucleus-independent chemical shift (NICS), and ring current strength (RCS). The computed out-of-plane component of the induced magnetic field at a distance (r) greater than or equal to 1.0 Å above the ring center correlates well (R2>0.99) with the RCS value. According to these criteria, fluorination has two effects on the C6 skeleton; concomitantly, the resonant effects diminish the π electron delocalization and the inductive effects decrease the charge density at the ring center and therefore reduce the magnitude of the paratropic current generated in this region. The equilibrium between both effects decreases aromaticity in the fluorinated benzene derivatives. These results can be extrapolated to determine the aromaticity of any derivative within the series of fluorinated benzene derivatives (C6H(6−n)Fn, where n=1–5). 相似文献
993.
An experimental investigation on gaseous mixing zones originated from the Richtmyer-Meshkov instability has been undertaken
in a square cross section shock tube. Mass concentration fields, of one of the two mixing constituents, have been determined
within the mixing zone when the shock wave passes from the heavy gas to the light one, from one gas to an other of close density,
and from the light gas to the heavy one. Results have been obtained before and after the coming back of the reflected shock
wave. The diagnostic method is based on the infrared absorption of one of the two constituents of the mixing zone. It is shown
that the mixing zone is strongly deformed by the wall boundary layer. The consequence is the presence of strong gradients
of concentration in the direction perpendicular to the shock wave propagation. Finally, it is pointed out that the mixing
goes more homogeneous when the Atwood number tends to zero. 相似文献
994.
In this paper, the Green's function technique is used to develop a solution of an infinite, piezoelectric medium containing
either an ellipsoidal cavity or a flat elliptical crack. The coupled elastic and electric fields both inside the cavity and
on the boundary of the cavity are obtained, and the stress intensity factor and the electric field intensity factor are also
obtained for an elliptical crack. It is found that; (1) the coupled elastic and electric fields inside the cavity keep uniform
when the external elastic field and electric field are constant; (2) the behavior of the stress and electric field components
in the neighborhood of the crack tip shows the classical
type of singularity.
The project supported by National Natural Science Foundation of China 相似文献
995.
V. S. Kirilyuk 《International Applied Mechanics》2006,42(11):1256-1269
The paper establishes the relationship between the static contact problems of elasticity and electroelasticity (in the absence
of friction) for a transversely isotropic half-space whose surface is the isotropy plane. This makes it possible to avoid
solving the electroelastic problem by finding all the characteristics of electroelastic contact from known cases of purely
elastic interaction. Moreover, the electroelastic state of the half-space can be fully described using a known harmonic function,
which is a solution of the purely elastic problem. The approach is exemplified by solving contact problems of electroelasticity
for flat, elliptic, two circular, conical, and paraboloidal (circular and elliptic in plan) punches
__________
Translated from Prikladnaya Mekhanika, Vol. 42, No. 11, pp. 69–84, November 2006. 相似文献
996.
B. D. Drobenko 《Journal of Applied Mechanics and Technical Physics》2005,46(5):624-634
This paper describes a procedure for the mathematical and numerical modeling of the thermomechanical behavior of electrically conducting solid bodies exposed to an external electromagnetic field. The constitutive equations for the electromagnetic field are the Maxwell equations written for the region of the solid body and the ambient medium. The stress-strain state of the solid is described using the relations for nonisothermal elastoplastic flow. The effects of the electromagnetic field on the heat-transfer and deformation processes are taken into account via heat release and ponderomotive forces, respectively. The relations between the electric and magnetic inductions and the corresponding field strengths are considered nonlinear. All physicomechanical parameters of the body material are temperature dependent.__________Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 5, pp. 14–26, September–October, 2005. 相似文献
997.
Helmut Harbrecht Michael Peters Markus Siebenmorgen 《Numerical Linear Algebra with Applications》2015,22(4):596-617
This article is dedicated to the rapid computation of separable expansions for the approximation of random fields. We consider approaches based on techniques from the approximation of non‐local operators on the one hand and based on the pivoted Cholesky decomposition on the other hand. Especially, we provide an a posteriori error estimate for the pivoted Cholesky decomposition in terms of the trace. Numerical examples are provided to validate and quantify the presented methods. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
998.
Solvability of Cauchy's problem in for fractional Hamilton–Jacobi equation (1.1) with subcritical nonlinearity is studied here both in the classical Sobolev spaces and in the locally uniform spaces. The first part of the paper is devoted to the global in time solvability of subcritical equation (1.1) in locally uniform phase space, a generalization of the standard Sobolev spaces. Subcritical growth of the nonlinear term with respect to the gradient is considered. We prove next the global in time solvability in classical Sobolev spaces, in Hilbert case. Regularization effect is used there to guarantee global in time extendibility of the local solution. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
999.
1000.