共查询到10条相似文献,搜索用时 171 毫秒
1.
A. E. Madison 《Physics of the Solid State》1999,41(2):160-163
A general algorithm is proposed for calculating the Θ series of SiC polytypes. The obtained Θ series of the main SiC polytypes
can be useful in calculating lattice sums, in particular when using the Mellin transform of the Θ series. By expanding the
Θ series in the Jacobi parameter, one obtains sequences of coordination numbers for crystallographically nonequivalent atomic
sites in the main SiC polytypes. A nontrivial interrelationship is demonstrated between these numerical sequences and the
local symmetry of the nonequivalent sites.
Fiz. Tverd. Tela (St. Petersburg) 41, 183–186 (February 1999) 相似文献
2.
B. P. Kondratyev 《Technical Physics》2010,55(12):1812-1813
A correction is derived to the expression for the radius of convergence of the Laplace series for the “internal” potential
of a homogenous circular torus. A spherical shell is found inside which the problem of expansion of the torus potential into
a power series should be specially solved. 相似文献
3.
C. Klimĉík 《Communications in Mathematical Physics》2001,217(1):203-228
A two dimensional gauge theory is canonically associated to every Drinfeld double. For particular doubles, the theory turns
out to be e.g. the ordinary Yang–Mills theory, the G/G gauged WZNW model or the Poisson σ-model that underlies the Kontsevich
quantization formula. We calculate the arbitrary genus partition function of the latter. The result is the q-deformation of the ordinary Yang–Mills partition function in the sense that the series over the weights is replaced by the
same series over the q-weights. For q equal to a root of unity the series acquires the affine Weyl symmetry and its truncation to the alcove coincides with the
Verlinde formula.
Received: 10 December 1999 / Accepted: 8 October 2000 相似文献
4.
Exciton absorption spectra in high-quality β-ZnP2 single crystals have been investigated at T=1.7 K for various directions of the wave vector and various polarization states of the radiation. It has been unambiguously
established that the additional high-energy A series, which in some works has been called a D series and ascribed to ZnP2 crystals, of so-called “rhombic” symmetry,1,8,10,11 is an intrinsic exciton of the β-ZnP2 series. A mixed mode has been detected for the first time, and the energy of the longitudinal exciton has been determined.
The selection rules for the exciton transitions have been analyzed by a group-theoretical approach, and the symmetry of the
nS states of the single exciton has been established on the basis of the experimental data — Γ
2
−
(z).
Fiz. Tverd. Tela (St. Petersburg) 41, 193–202 (February 1999) 相似文献
5.
Yu. M. Smirnov 《Journal of Applied Spectroscopy》2007,74(5):613-617
The behavior of excitation cross sections of the strontium atom was studied experimentally in the spectral series 5s4d1D2-5snf1F
3
o
in the range n = 4–26, and also the optical excitation functions for lines in the same series in the range n = 4–12. It was
established that the beginning of the series is perturbed. The effect of the perturbation is manifested both in the irregular
course of the dependence of the absolute values of the cross sections on n, and in the difference between the shapes of the
optical excitation functions for different terms of the series. The results obtained are compared with available experimental
data.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 557–560, September–October, 2007. 相似文献
6.
Horst R. Beyer 《Communications in Mathematical Physics》1999,204(2):397-423
The completeness of the quasinormal modes of the wave equation with P?schl–Teller potential is investigated. A main result
is that after a large enough time t
0, the solutions of this equation corresponding to &C
∞-data with compact support can be expanded uniformly in time with respect to the quasinormal modes, thereby leading to absolutely
convergent series. Explicit estimates for t
0 depending on both the support of the data and the point of observation are given. For the particular case of an “early” time
and zero distance between the support of the data and observational point, it is shown that the corresponding series is not absolutely convergent, and hence that there is no associated sum which is independent of the order of summation.
Received: 10 March 1998 / Accepted: 1 February 1999 相似文献
7.
V. I. Baranov 《Journal of Applied Spectroscopy》2000,67(2):198-204
Calculations of the excited-state structure and of the absorption and radiation spectra of trans-β-methylstyrene are performed
by the parametric method for models of the first and second approximations. Only three of the parameters, being constant in
a series of related compounds, are used for molecular fragments. In the calculation, the main regularities observed in electronic
spectra are reproduced, and an analysis and interpretation of their fine vibrational structure are carried out. The use of
the model of the second approximation with a single additional parameter allows more accurate reproduction of angular deformations
of the molecule under excitation and of the characteristic changes observed in the low-frequency spectral region in the series
of diphenyl polyenes, stilbene, styrene, and methylstyrene molecules. It is shown that the parameters of the second approximation
(just as of the first one) possess the transference property in the homological series of molecules. In modeling complex molecules
in excited states and their vibronic spectra, the parametric method is more efficient than the ab initio one.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 2, pp. 148–153, March–April, 2000. 相似文献
8.
Using the imaginary time method, we study the structure of the perturbation series for the hydrogen atom in electric ℰ and
magnetic ℋ fields. It is shown that there is a “critical” value of the ratio γ=ℋ|ℰ at which the perturbation series for the ground state changes from having a fixed sign (for γ<γ
c
) to having a variable sign (for γ>γ
c
). This conclusion is confirmed by direct higher-order perturbation calculations. The change in the asymptotic regime is explained
by competition among the contributions of the various complex trajectories that describe the subbarrier motion of the electrons.
Here the parameter γ
c
depends on the angle θ between the electric and magnetic fields.
Zh. éksp. Teor. Fiz. 113, 2047–2055 (June 1998) 相似文献
9.
Chun-Lan Ma Yu-Chang Chen Diu Nghiem Allen Tseng Pao-Chieh Huang 《Applied Physics A: Materials Science & Processing》2011,104(1):325-328
Self-consistent calculations of electron density distribution from first principles for a series of semi-infinite metals show
that the electron density almost drops to zero at 8.5 a.u. away from a metal surface. The electron densities in a series of
bimetallic-electrode systems with a distance between the two electrodes of 21.7 a.u. are further investigated. Spin-polarized
calculations of electron density for nonmagnetic and magnetic bimetallic-electrode systems are compared. Our work is helpful
for first principles investigation of spin-dependent metal–molecule–metal tunneling junctions. 相似文献
10.
Let Γ be a Fuchsian group of the first kind acting on the hyperbolic upper half plane
\mathbbH{\mathbb{H}}, and let
M = G\\mathbbH{M = \Gamma\backslash \mathbb{H}} be the associated finite volume hyperbolic Riemann surface. If γ is a primitive parabolic, hyperbolic, resp. elliptic element
of Γ, there is an associated parabolic, hyperbolic, resp. elliptic Eisenstein series. In this article, we study the limiting
behavior of these Eisenstein series on an elliptically degenerating family of finite volume hyperbolic Riemann surfaces. In
particular, we prove the following result. The elliptic Eisenstein series associated to a degenerating elliptic element converges
up to a factor to the parabolic Eisenstein series associated to the parabolic element which fixes the newly developed cusp
on the limit surface. 相似文献