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991.
Translated from Aktual'nye Voprosy Prikladnoi Matematiki, pp. 222–228, 1989. 相似文献
992.
Marc Chaperon Mathilde Kammerer-Colin De Verdière Santiago López De Medrano 《Comptes Rendus Mathematique》2006,342(5):301-305
Near partially elliptic rest points of generic families of vector fields or transformations, many types of normally hyperbolic invariant compact manifolds can appear, diffeomorphic to intersections of quadrics. To cite this article: M. Chaperon et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
993.
Banach空间二阶非线性脉冲微分-积分方程的极值解 总被引:1,自引:0,他引:1
通过建立一个新的比较定理研究了B anach空间二阶非线性混合型脉冲微分-积分方程初值问题的极值解,所得结果推广和改进了现有文献的主要结果. 相似文献
994.
M. Maamache S. Menouar L. Krache 《International Journal of Theoretical Physics》2006,45(11):2191-2198
By using the Lewis-Riesenfeld theory and algebraic method, we present an alternative approach to obtain the exact solution of time-dependent Hamiltonian systems involving quadratic, inverse quadratic and (1/x)p+p(1/x) terms. This solution is discussed and compared with that obtained by Choi, J. R. (2003). International Journal of Theoretical Physics
42, 853].
PACS: 03.65Ge; 03.65Fd; 03.65Bz 相似文献
995.
Defect formation and annealing processes in fullerene C60 at T = (4000–6000) K are studied using molecular dynamics with a tight-binding potential. The cluster lifetime until fragmentation, which proceeds, as a rule, through the loss of a C2 dimer, has been found as a function of temperature. The activation energy and the frequency factor in the Arrhenius equation for the fragmentation rate have been found to be E a = (9.2 ± 0.4) eV and A = (8 ± 1) × 1019s?1. It is shown that fragmentation can occur already after the C60 cluster loses its spherical shape. This fact must be taken into account in theoretical calculations of E a. 相似文献
996.
F.J. Olmo A. Quirantes A. Alcntara H. Lyamani L. Alados-Arboledas 《Journal of Quantitative Spectroscopy & Radiative Transfer》2006,100(1-3):305-314
There is experimental evidence that the non-sphericity of certain atmospheric particles can cause scattering properties different from those predicted by standard Mie theory. Numerous studies indicate the need to consider the presence of non-spherical particles in modeling the optical properties of atmospheric aerosols. On the other hand, natural aerosols show a great variety of shapes, making difficult a realistic choice of a particle shape (or shape mixture) model. In this paper, we test a parameterization of the particle shape in the retrieval of size distribution, phase function, single scattering albedo and asymmetry parameter from direct and sky-radiance measurements. For this purpose we have substituted the Kernel based on the Mie theory included in the model SKYRAD.PACK by one derived for non-spherical particles. The method is applied under different atmospheric conditions, including Saharan dust outbreak, polluted and local mineral episodes. We compare the results with those obtained by the well known spheroids algorithm used in the AERONET network. 相似文献
997.
It is shown that the condition υ > υp (ω), which is necessary in order to trigger the Vavilov-Cherenkov effect, determines the interval of radiated frequencies
and it alone cannot establish a strong restriction to the velocity of the particle. It is exhibited that it is possible to
define a general lower bound for the velocity of the particle, which does not depend on the frequency when both, a specific
response of the medium is taken into account and the mentioned condition is considered. The minimum value of the phase velocity
of light in the medium determines the existence of such general lower bound. 相似文献
998.
Optimum experimental conditions for the brittle fracture technique applied in trace metal analysis of biological material are described. The efficiency of the technique was tested by sieve and radio-tracer experiments. Numerical results are presented for human placenta submitted to eight different grinding procedures. 相似文献
999.
1000.