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991.
Gu-Qiang Li 《Theoretical and Mathematical Physics》2007,151(1):586-589
We use the Parikh-Wilczek method to treat Hawking radiation as a tunneling process across the event horizon and calculate
the emission rate of a Gibbons-Maeda dilaton black hole. We show that if self-gravitation is taken into account, then the
radiation deviates from the purely thermal spectrum, and the corrected spectrum is consistent with an underlying unitary theory.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 151, No. 1, pp. 172–175, April, 2007. 相似文献
992.
In this paper we investigate the electrostatic problem of determining conductivity profiles from the knowledge of boundary
currents and voltages. We obtain an improved estimate for the voltage potential of a two-dimensional conductor having finitely
many circular inclusions and piecewise constant conductivity profile. We derive an asymptotic expansion for the voltage potential
in terms of the reference voltage potential and the location, size, and conductivity of the inhomogeneities. This representation
is used to formulate the nonlinear least squares problem for estimating the location and size of the inhomogeneities. Required
boundary data for the voltage potential are generated numerically by solving a system of integral equations. Computational
experiments are presented to demonstrate the effectiveness of our identification procedure. 相似文献
993.
Semyon Alesker 《Geometric And Functional Analysis》2007,17(4):1321-1341
This is a non-technical survey of a recent theory of valuations on manifolds constructed in [A10], [A11], [AF] and [A12],
and actually a guide to this series of articles. We also review some recent related results obtained by a number of people.
Received: February 2006, Revision: June 2006, Accepted: June 2006 相似文献
994.
This work presents a formulation based on UPML for truncating conductive media by using a local and non-orthogonal coordinate
system to solve Maxwell’s equations by the FDTD method. The detailed procedure for obtaining the UPML equations for this case
is shown and the complete equation set is provided. 相似文献
995.
Charge density fluctuation of low frequency in a dusty plasma 总被引:2,自引:0,他引:2
The charge density fluctuation of low frequency in a dusty plasma, which is derived from the longitudinal dielectric permittivity
of the dusty plasma, has been studied by kinetic theory. The results show that theP value, which describes the relative charge density on the dust in the plasma, and the charging frequency of a dust particle
Ω
c
, which describes the ratio of charge changing of the dust particles, determine the character of the charge density fluctuation
of low frequency. For a dusty plasma ofP≪1, when the charging frequency Ω
c
, is much smaller than the dusty plasma frequency ωd, there is a strong charge density fluctuation which is of character of dust acoustic eigenwave. For a dusty plasma ofP≫1, when the frequency Ω
c
, is much larger than ω
d
there are weaker fluctuations with a wide spectrum. The results have been applied to the ionosphere and the range of radius
and density of dust particles is found, where a strong charge density fluctuation of low frequency should exist. 相似文献
996.
在本文中引入了泛代数的二次扩张的概念,解决了TU-EC(A)和UT-EC(A)的存在、真类和基数问题,范畴TU-EC(A)(及UT-EC(A)),并得到了有关二次扩张的几个同构定理,还对一点二次扩张作了讨论。 相似文献
997.
In this paper we establish a sharp result concerning integral mean estimates for self-reciprocal polynomials. 相似文献
998.
999.
ADegenerateStefanProblemwithTwoFreeBoundaries¥(李辉来)LiHuilai(DepartmentofMathematics,JilinUniversity,Changchun,130023)Abstract... 相似文献
1000.
Using the theoretically calculated point-defect total-energy values of Baraff and Schlüter in GaAs, anamphoteric-defect model has been proposed by Walukiewicz to explain a large number of experimental results. The suggested amphoteric-defect system consists of two point-defect species capable of transforming into each other: the doubly negatively charged Ga vacancyV
Ga
2–
and the triply positively charged defect complex (ASGa+V
As)3+, with AsGa being the antisite defect of an As atom occupying a Ga site andV
As being an As vacancy. When present in sufficiently high concentrations, the amphoteric defect systemV
Ga
2–
/(AsGa+V
As)3+ is supposed to be able to pin the GaAs Fermi level at approximately theE
v
+0.6 eV level position, which requires that the net free energy of theV
Ga/(AsGa+V
As) defect system to be minimum at the same Fermi-level position. We have carried out a quantitative study of the net energy of this defect system in accordance with the individual point-defect total-energy results of Baraff and Schlüter, and found that the minimum net defect-system-energy position is located at about theE
v
+1.2 eV level position instead of the neededE
v
+0.6 eV position. Therefore, the validity of the amphoteric-defect model is in doubt. We have proposed a simple criterion for determining the Fermi-level pinning position in the deeper part of the GaAs band gap due to two oppositely charged point-defect species, which should be useful in the future. 相似文献