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91.
L. C. Wrobel 《国际流体数值方法杂志》1993,16(9):845-854
This paper presents a formulation of the boundary element method (BEM) for solution of axisymmetric cavity flow problems. The governing equation is written in terms of Stokes' stream function, requiring a new fundamental solution to be found. The iterative procedure for adjusting the free-surface position is similar to that used for planar cavity flows. Numerical results are compared with finite difference and finite element solutions, showing the robustness of the BEM model. 相似文献
92.
R. J. Temkin 《International Journal of Infrared and Millimeter Waves》1981,2(4):629-650
An analytic theory has been derived for determining the eigenfrequencies, RF-field distribution and Q of the TEmpq modes of a gyrotron resonator consisting of a circular cylinder joined to a slowly tapered section. Explicit results are obtained for a linear taper. The cavity modes are found to have an RF-field distribution which is useful for prebunching the electron beam and enhancing efficiency. For high Q cavities, the cavity Q depends on axial mode number q as q–2, which is important for mode discrimination. Proper selection of taper length is found to reduce the Q of high q modes, also aiding in mode discrimination. The present approach may be applied to other forms of weakly irregular cavities, such as cavities with nonlinear tapers.Work supported by U.S.D.O.E. Contract DE-AC02-78ET-51013Supported by U.S. Department of Energy 相似文献
93.
A residual method of finite differencing the governing differential equation for the elliptic transport problem is presented. The new finite differencing technique is applied to (1) the one-dimensional transport problem and (2) the cavity flow problem for numerical illustrations. The results indicate the validity of the residual method of finite differencing. The usual method of term-by-term finite differencing, and considerations such as central differencing, hybrid differencing and upwind differencing are not needed in the present residual method. 相似文献
94.
K.F. Song S. Kassi V.I. Perevalov 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(3):332-31
In a previous contribution [Kassi S, Song KF, Campargue A. High sensitivity CW-cavity ring down spectroscopy of 12CO2 near 1.35 μm (I): line positions. JQSRT 110 (2009) 1801-1814], the line positions analysis of the high sensitivity absorption spectrum of carbon dioxide has been reported in the 7123-7793 cm−1 region. In this second contribution, the spectral region investigated by CW-cavity ring down spectroscopy has been extended up to 7917 cm−1. It added about 400 lines to our previous list of about 2500 transitions. These additional lines include transitions belonging to six newly observed 12C16O2 bands for which we provide the spectroscopic parameters. Over the whole 7123-7917 cm−1 region, the accurate intensities of about 2900 lines belonging to four isotopologues (12C16O2, 13C16O2, 16O12C18O and 16O12C17O) were retrieved with an average accuracy of 3%. Intensity values range between 1.2×10−29 and 4.1×10−25 cm/mol. Compared to the present version of the carbon dioxide spectroscopic databank recently adopted for the HITRAN database, important deviations were evidenced for some weak bands of the main isotopologue. The CW-CRDS intensity data relative to a total of 46 12C16O2 bands together with selected intensity information available in the literature for nine bands have been fitted simultaneously using the effective operators approach. The ΔP=11 set of the 12C16O2 effective dipole moment parameters has been refined leading to a much better agreement with the measured intensity values. In addition, the ΔP=10 effective dipole moment parameters of the 16O12C18O minor isotopologue were determined for the first time. The obtained results will help to improve the carbon dioxide spectroscopic databank (CDSD). 相似文献
95.
Agnès Perrin Samir Kassi 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(15):2246-2255
The high-resolution absorption spectrum of the 4ν1+ν3 band of the 14N16O2 molecule was recorded by CW-Cavity Ring Down Spectroscopy between 6575 and 6700 cm−1. The assignments involve energy levels of the (4,0,1) vibrational state with rotational quantum numbers up to Ka=8 and N=48. A large majority of the spin-rotation energy levels were reproduced within their experimental uncertainty using a theoretical model which takes explicitly into account the Coriolis interactions between the spin-rotational levels of the (4,0,1) vibrational state and those of the (4,2,0) and of (0,9,0) dark states, the anharmonic interactions between the (4,2,0) and (0,9,0) states together with the electron spin-rotation resonances within the (4,0,1), (4,2,0) and (0,9,0) states. Precise vibrational energies, rotational, spin-rotational, and coupling constants were determined for the {(4,2,0), (0,9,0), (4,0,1)} triad of interacting states. Using these parameters and the value of the transition dipole-moment operator determined from a fit of a selection of experimental line intensities, the synthetic spectrum of the 4ν1+ν3 band was generated and is provided as Supplementary Material. 相似文献
96.
We propose the optical generation of W states for three atomic and four atomic qubits, with each qubit trapped in a separate cavity and coupled to the cavity laser. A single-photon source and two classical fields are employed in the present scheme. By encoding the quantum information of each qubit on the degenerate ground states of the atom, we obtain the atomic entanglement that is relatively stable against spontaneous emission. It is demonstrated that the three- and four-atomic W states can be produced deterministically via a proper manipulation of the atom-cavity interaction sequence and time. Generalization of the present scheme to prepare multi-atomic W states is also discussed. 相似文献
97.
An efficient dispersion compensating fiber (DCF) design is proposed based on a coaxial fiber structure, which provides dispersion compensation over a broad wavelength region matching that of an erbium-doped fiber amplifier gain spectrum. The design can provide dispersion coefficient that is nearly twice those of existing DCF designs. Due to the basic nature of the dispersion curve of this design, the total link dispersion cannot only be compensated but also can be flattened. 相似文献
98.
Qian Yang Bing-Yu Zhang Wei-Dong Ye Jian-Yong Yuan Duan-Jun Xu Jing-Jing Nie 《Journal of chemical crystallography》2008,38(9):659-661
Abstract The title compound (common name eplerenone), C24H30O6, is an aldosterone receptor antagonist. From the isopropyl acetate solution the compound crystallizes in monoclinic space
group P 21 with a = 8.811(1) ?, b = 11.250(1) ?, c = 11.079(1) ?, β = 93.822(12)°, Z = 2. The molecule contains three six membered rings, two five membered rings and one three membered ring. Both five membered
rings display envelope conformation, whereas three six membered rings show different conformation: chair, half-chair and envelope.
In the crystal the eplerenone molecules link to one another via intermolecular weak C–H···O hydrogen bonding to form the smaller
cavity of 12.0(1) ?3 between eplerenone molecules, no solvent molecule filled in this cavity.
Index Abstract In the title molecule three six-membered rings show different conformation. Weak C–H···O hydrogen bonding links adjacent molecules
to form the small cavity 12.0(1) ?3, no solvent molecule filled in the cavity.
相似文献
99.
D. PortesJr. H. Rodrigues S. B. Duarte B. Baseia 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(1):145-149
We study the exchange of states in coupled fields along their time
evolution. The coupling is described by a quadratic form in terms of
annihilation and creation operator in the field Hamiltonian. An analytical
approach is employed to describe the time evolution of the field state in
Fock's space and the conditions for an arbitrary initial states to be
transferred with 100% fidelity is determined. We show that only for initial
states C0|0>+CN|N>, this situation can occurs. The important
|1〉↔|0〉 qubits transfer is a particular
case of this transference of number state. The relation between the coupling
constant and characteristic field frequencies for complete state
transference is also determined. 相似文献
100.
The quantum mechanical phase distribution and the quantum oscillations of population are studied for a cavity field togetherwith
a driven classical field. The atom is sent through the cavity and driven by a classical field. Also the time evolution of
the system including decay is obtained. The graph showing the Rabi oscillations for this system is changed into a bit pattern
from the system without decay. The phase probability function is also affected due to the presence of cavity decay. 相似文献