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We prove that the renormalized solutions of the Boltzmann equation considered in a bounded domain with different types of (kinetic) boundary conditions converge to the Stokes‐Fourier system with different types of (fluid) boundary conditions when the main free path goes to zero. This extends the work of F. Golse and D. Levermore [9] to the case of a bounded domain. © 2003 Wiley Periodicals, Inc. 相似文献
4.
We give here a complete derivation of the Navier-Stokes-Fourier equations from a model collisional kinetic equation, the BGK model. Though physically unrealistic, this model shares some common features with more classical models such as the Boltzmann equation.Then the program developed by Bardos, Golse and Levermore [Fluid dynamic limits of kinetic equations II. Convergence proofs for the Boltzmann equation, Comm. Pure Appl. Math. 46 (5) (1993) 667-753] to study hydrodynamic limits of the steady Boltzmann equation, and extended by Lions and Masmoudi [From Boltzmann equations to Navier-Stokes equations I, Archive Rat. Mech. Anal. 158 (2001) 173-193] in the time-dependent case, can be adapted here, and gives the expected convergence result provided that the particle density f satisfies some integrability assumption.The originality of the present work is to remove this assumption by establishing refined a priori estimates. The crucial idea is to decompose f as (f−Mf)+Mf where Mf is the local Maxwellian associated with f. The first term is then estimated by means of the entropy dissipation, while the other is smooth in v. A mixing property of the operator (ε∂t+v.∇x) allows to transfer some of this extra-integrability on the variable x. 相似文献
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Fluorotricyanomethane is prepared from potassium tricyanomethanide and perchlorylfluoride. The crystal structure of this compound (orthorhombic, space group P212121, with a=6.270, b=6.734, c=11.776 Å) has been determined by X-ray analysis. The results are discussed in relation to those of (NC)3C? X (X=? CH3, ? Cl, ? Br or ? CN). 相似文献
7.
Reinhart Ahlrichs 《Chemical physics letters》1975,34(3):570-574
It is shown that HF computations which yield ?i > 0 for an occupied MO do not minimize the HF energy. If ?i > 0, which frequently occurs in the RHF treatment of negative ions, one can reduce ?i to zero and simultaneously lower EHF by an appropriate admixture of a continuum function to the corresponding MO ?. We propose a modification of the HF model that takes these facts into account. Applications to the systems O2?, N3?, C4?, S2?, O22?, C22? are reported and discussed. 相似文献
8.
HIV infection leads to progressive alterations of humoral immune functions, including B-cell hyperplasia, hypergammaglobulinemia,
elevated autoantibody titers, a poor response to neoantigens and mitogens, polyclonal B-cell activation, monoclonal gammopathies,
and a significant deterioration of the antigen-specific humoral response. There is also an important isotypic imbalance of
the antibody (Ab) response in the systemic compartment and a profound modification of mucosal immune functions. These abnormalities
may contribute to disease progression and development of opportunistic infections, despite the presence of serum-neutralizing
anti-HIV Abs. Equally important are the abnormal selection mechanisms of the Ab repertoire that seem to be responsible for
B-cell clonal deletions. The VH3 gene family, which encodes for approx 50% of immunoglobulins expressed by peripheral B-cells from normal adults, is underrepresented
in human monoclonal antibodies to HIV-1 and in the peripheral B-cells of AIDS patients. These abnormalities, together with
features of germinal center alteration, could be responsible for the clonal elimination of a subset of B-cells, and could
contribute to HIV pathogenesis. 相似文献
9.
Laure F Herbette G Faure R Bianchini JP Raharivelomanana P Fogliani B 《Magnetic resonance in chemistry : MRC》2005,43(1):65-68
Three new friedelane-type triterpenoids, 3,4-secofriedelan-3,28-dioic acid (1), 27-hydroxyacetate canophyllic acid (2) and 3-oxo-27-hydroxyacetate friedelan-28-oic acid (3), were isolated from the leaves of Calophyllum inophyllum (Clusiaceae) grown in French Polynesia. Their structures were established by the concerted application of 2D NMR techniques including gs-COSY, gs-HMQC and gs-HMBC. 相似文献
10.
Reinhart Ahlrichs 《Theoretical chemistry accounts》1974,33(2):157-167
Methods are described that allow for an efficient evaluation of two-electron integrals over contracted Gaussian lobe functions. The improvement in computational speed is achieved by avoiding the computation of integrals that are: 1. sufficiently small on numerical reasons, 2. zero by symmetry, 3. identical to other integrals by symmetry. Examples of the effectiveness of these techniques are included. We also report the timings for a further processing of two-electron integrals in a Hartree Fock and correlation energy computation. 相似文献