Literature studies of the lattice Boltzmann method (LBM) demonstrate hydrodynamics beyond the continuum limit. This includes exact analytical solutions to the LBM, for the bulk velocity and shear stress of Couette flo...
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Literature studies of the lattice Boltzmann method (LBM) demonstrate hydrodynamics beyond the continuum limit. This includes exact analytical solutions to the LBM, for the bulk velocity and shear stress of Couette flow under diffuse reflection at the walls through the solution of equivalent moment equations. We prove that the bulk velocity and shear stress of Couette flow with Maxwell-type boundary conditions at the walls, as specified by two-dimensional isothermal lattice Boltzmann models, are inherently linear in Mach number. Our finding enables a systematic variational approach to be formulated that exhibits superior computational efficiency than the previously reported moment method. Specifically, the number of partial differential equations (PDEs) in the variational method grows linearly with quadrature order while the number of moment method PDEs grows quadratically. The variational method directly yields a system of linear PDEs that provide exact analytical solutions to the LBM bulk velocity field and shear stress for Couette flow with Maxwell-type boundary conditions. It is anticipated that this variational approach will find utility in calculating analytical solutions for novel lattice Boltzmann quadrature schemes and other flows.
A general technique for the generation of canonical channel models and demonstrate the application of the technique to time-frequency and time-scale integral kernel operators is developed. As an example, the derivatio...
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We present the first results of an ab initio coupled-channel calculation of electron capture to the n=2 states of hydrogen in proton-hydrogen collisions using symmetrized variational (SV) continuum distorted-wave (CDW...
We present the first results of an ab initio coupled-channel calculation of electron capture to the n=2 states of hydrogen in proton-hydrogen collisions using symmetrized variational (SV) continuum distorted-wave (CDW) theory. In SVCDW theory the collision ansatz includes both outgoing- and incoming-wave components in the wave functions, and represents in a compact and elegant form a very complete basis set for describing the electron capture process. We calculate total cross sections for nonresonant capture to the 2s and 2p states of the projectile, in the energy range 7–150 keV. The results are a substantial improvement over a previous variational CDW theory, and in particular are found to be in good accord with the available experimental data.
In the present paper we investigate the influence of measurements on the quantum dynamics of degenerate Bose atoms gases in a symmetric double well. We show that continuous measurements enhance asymmetry on the densit...
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In the present paper we investigate the influence of measurements on the quantum dynamics of degenerate Bose atoms gases in a symmetric double well. We show that continuous measurements enhance asymmetry on the density distribution of the atoms and broaden the parameter regime for self-trapping. We term this phenomenon as nonlinear quantum Zeno effect in analog to the celebrated Zeno effect in a linear quantum system. Under discontinuous measurements, the self-trapping due to the atomic interaction in the degenerate bosons is shown to be destroyed completely. Underlying physics is revealed and possible experimental realization is discussed.
The second-order Sigma-Delta (ΣΔ) scheme with linear quantization rule is analyzed for quantizing finite unit-norm tight frame expansions for Rd. Approximation error estimates are derived, and it is shown that for c...
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In this paper we analyse an infimal convolution type regularisation functional called TVL∞ , based on the total variation (TV) and the L ∞ norm of the gradient. The functional belongs to a more general family of TVL...
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In the present paper, we evaluated the core heating performance for FIREX-I class experiments by separating the heating process into 3 phases;1) energy coupling from heating laser to fast electrons η1, 2) fast electr...
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ISBN:
(纸本)9781622763313
In the present paper, we evaluated the core heating performance for FIREX-I class experiments by separating the heating process into 3 phases;1) energy coupling from heating laser to fast electrons η1, 2) fast electron core hitting rate η2 and 3) energy deposition rate in the core η3. Theobtained values and net coupling efficiencies ηnet for the cases w/o and with pre-plasma aresummarized in Table I. The existence of pre-plasma reduces the net coupling by 1/4. So reductionin pre-pulse level is indispensable for high heating efficiency. Another critical issue is the beamdivergence. In the present analysis, the field effects such as self-guiding by resistive B-field arenot included. When the beam divergence is as large as that obtained here, however, we cannotexpect the self-guiding effect on beam transport [4] So we should find the methodsfor reduction in the beam divergence and /or additional beam-collimation method to enhance the heating efficiency. Otherwise, the tip should be as close to core as possible. The further investigations (e.g., more practical FP simulations for transport process, and double cone effects) are going on.
Motivated by the structure reconstruction problem in cryo-electron microscopy, we consider the multi-target detection model, where multiple copies of a target signal occur at unknown locations in a long measurement, f...
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In this article, the authors show the existence of global solution of two-dimensional viscous Camassa-Holm (Navier-Stokes-alpha) (NS-α) equations. The authors also prove that the solution of the NS-α equations conve...
In this article, the authors show the existence of global solution of two-dimensional viscous Camassa-Holm (Navier-Stokes-alpha) (NS-α) equations. The authors also prove that the solution of the NS-α equations converges to the solution of the 2D NS equations in the inviscid limit and give the convergence rate of the difference of the solution.
Power spectrum estimation is an important tool in many applications, such as the whitening of noise. The popular multitaper method enjoys significant success, but fails for short signals with few samples. We propose a...
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