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901.
CAO Ce-Wen YANG Xiao 《理论物理通讯》2008,49(1):31-36
Special solution of the (2+1)-dimensional Sawada Kotera equation is decomposed into three (0+1)- dimensional Bargmann flows. They are straightened out on the Jacobi variety of the associated hyperelliptic curve. Explicit algebraic-geometric solution is obtained on the basis of a deeper understanding of the KdV hierarchy. 相似文献
902.
Rolf Pettersson 《Journal of statistical physics》1990,59(1-2):403-440
This paper considers the linear space-inhomogeneous Boltzmann equation in a convex, bounded or unbounded bodyD with general boundary conditions. First, mildL
1-solutions are constructed in the cutoff case using monotone sequences of iterates in an exponential form. Assuming detailed balance relations, mass conservation and uniqueness are proved, together with anH-theorem with formulas for the interior and boundary terms. Local boundedness of higher moments is proved for soft and hard collision potentials, together with global boundedness for hard potentials in the case of a nonheating boundary, including specular reflections. Next, the transport equation with forces of infinite range is considered in an integral form. Existence of weakL
1-solutions are proved by compactness, using theH-theorem from the cutoff case. Finally, anH-theorem is given also for the infinite-range case. 相似文献
903.
V. G. Ferreira N. Mangiavacchi M. F. Tom A. Castelo J. A. Cuminato S. McKee 《国际流体数值方法杂志》2004,44(4):347-375
This paper presents a finite difference technique for solving incompressible turbulent free surface fluid flow problems. The closure of the time‐averaged Navier–Stokes equations is achieved by using the two‐equation eddy‐viscosity model: the high‐Reynolds k–ε (standard) model, with a time scale proposed by Durbin; and a low‐Reynolds number form of the standard k–ε model, similar to that proposed by Yang and Shih. In order to achieve an accurate discretization of the non‐linear terms, a second/third‐order upwinding technique is adopted. The computational method is validated by applying it to the flat plate boundary layer problem and to impinging jet flows. The method is then applied to a turbulent planar jet flow beneath and parallel to a free surface. Computations show that the high‐Reynolds k–ε model yields favourable predictions both of the zero‐pressure‐gradient turbulent boundary layer on a flat plate and jet impingement flows. However, the results using the low‐Reynolds number form of the k–ε model are somewhat unsatisfactory. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
904.
905.
V.-M. HokkanenGh. Moro?anu 《Journal of Mathematical Analysis and Applications》2002,266(2):432-450
The regularity of the solution of the telegraph system with nonlinear monotone boundary conditions is investigated by two methods. The first one is based on D'Alembert-type representation formulae for the solution. In the second method the telegraph system is reduced to a linear Cauchy problem with a locally Lipschitzian functional perturbation; then regularity results are established by appealing to the theory of linear semigroups. 相似文献
906.
Averaging techniques are popular tools in adaptive finite element methods since they provide efficient a posteriori error estimates by a simple postprocessing. In the second paper of our analysis of their reliability, we consider conforming -FEM of higher (i.e., not of lowest) order in two or three space dimensions. In this paper, reliablility is shown for conforming higher order finite element methods in a model situation, the Laplace equation with mixed boundary conditions. Emphasis is on possibly unstructured grids, nonsmoothness of exact solutions, and a wide class of local averaging techniques. Theoretical and numerical evidence supports that the reliability is up to the smoothness of given right-hand sides.
907.
A Remark on the Rank Conjecture 总被引:1,自引:0,他引:1
Rob De Jeu 《K-Theory》2002,25(3):215-231
We prove a result about the action of -operations on the homology of linear groups. We use this to give a sharper formulation of the rank conjecture as well as some shorter proofs of various known results. We formulate a conjecture about how the sharper formulation of the rank conjecture together with another conjecture could give rise to a different point of view on the isomorphism between
and K_n^{(p)} (F)$ for an infinite field F, and we prove part of this new conjecture. 相似文献
908.
For semigroups (e
tA
)
t0 of operators on a Hilbert space, we give conditions guaranteeing trace estimates of the polynomial type
0$$
" align="middle" border="0">
, where
denotes the trace class. As an application we present higher order analogues of results due to E.B. Davies, B. Simon and M. van den Berg of the type
0$$
" align="middle" border="0">
, for certain unbounded domains
, e.g. spiny urchin domains. 相似文献
909.
V. I. Deineka N. G. Gabruk L. A. Deineka L. A. Manokhina 《Chemistry of Natural Compounds》2002,38(5):410-412
Oil from stones of nine plants representing seven Rosaceae genera was studied by reversed-phase HPLC with refractive-index detection. Internal normalization using the incremental approach determined the qualitative and quantitative composition of the oil triglycerides. Triglycerides of Cerasus vulgaris Mill., C. avium Moench., and Prunus padus consisted of palmitic, stearic, oleic, linoleic, and C18:3 (-eleostearic) acids. Triglycerides of Prunus tomentosa Thunb. Wall., P. domestica L., Armeniaca vulgaris Lam., P. persica (L.) Batsch, nectarine, and P. amygdalinus did not contain C18:3 acid. 相似文献
910.