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91.
92.
We adopt the potential harmonics expansion method for anab initio solution of the many-body system in a Bose condensate containing interacting bosons. Unlike commonly adopted mean-field theories,
our method is capable of handling two-body correlation properly. We disregard three- and higher-body correlations. This simplification
is ideally suited to dilute Bose Einstein condensates, whose number density is required to be so small that the interparticle
separation is much larger than the range of two-body interaction to avoid three- and higher-body collisions, leading to the
formation of molecules and consequent instability of the condensate. In our method we can incorporate realistic finite range
interactions. We calculate energies of low-lying states of a condensate containing23Na atoms and some thermodynamical properties of the condensate. 相似文献
93.
94.
E.D. Aydin S. Katsimichas 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,95(3):349-363
In this paper, the finite-element-spherical harmonics (FE-PN) method is applied to the solution of transient Boltzmann transport equation. Firstly, transport and diffusion calculations are obtained for homogeneous and inhomogeneous circular regions. Results are compared in order to show the effects of different absorption coefficient values on the propagation of photons. Significant differences between two theories are shown to occur especially in cases when the absorption is increased. Secondly, to validate the FE-PN method, results from this method are compared with Monte Carlo calculations for different cases. Comparisons show good agreements between FE-transport and Monte Carlo solutions and demonstrate the correctness of the results obtained. 相似文献
95.
96.
The chirped Mo/Si multilayer mirror in the extreme ultraviolet region is designed to obtain sub-femtosecond pulses from high-order harmonics. Numerical simulations of temporal profile of the pulses are made for superposition of incident high-order harmonics and that of reflected ones by the chirped multilayer mirror.The normal incidence reflectivity and chirp in the wavelength range of 12.5 - 16.5 nm are 6.7% ±0.5%and-3617±171 as2, respectively. Simulation results indicate that the designed chirped multilayer mirror can be used for producing 104-as pulses. 相似文献
97.
No Heading Some aspects of the N dimensional Kratzer-Fues potential are discussed, which is an extension of the combined Coulomb-like potential with inverse quadratic potential in N dimensions. The analytical solutions obtained (eigenfunctions and eigenvalues) are dimensionally dependent, so also, the solutions depend on the value of the coefficient of the inverse quadratic term. The expectation values for < r–2 >, < r–1 > and the virial theorem for this potential are obtained and the values are also dimensions and parameter dependent. 相似文献
98.
Calculation of the diffracted amplitude for the diffracting aperture on a sphere is briefly reviewed. Explicit formulas are
given to compute the diffracted amplitude. In these formulas the real wave and evanescent wave contributions are discussed. 相似文献
99.
The paper obtains error estimates for approximation by radial basis functions on the sphere. The approximations are generated
by interpolation at scattered points on the sphere. The estimate is given in terms of the appropriate power of the fill distance
for the interpolation points, in a similar manner to the estimates for interpolation in Euclidean space. A fundamental ingredient
of our work is an estimate for the Lebesgue constant associated with certain interpolation processes by spherical harmonics.
These interpolation processes take place in ``spherical caps' whose size is controlled by the fill distance, and the important
aim is to keep the relevant Lebesgue constant bounded. This result seems to us to be of independent interest.
March 27, 1997. Dates revised: March 19, 1998; August 5, 1999. Date accepted: December 15, 1999. 相似文献
100.