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71.
In this article, we extended main results on outer operators of [6] to the symmetric Hardy spaces, when associated subdiagonal algebra is finite. 相似文献
72.
Let M be a matroid on E, representable over a field of characteristic zero. We show that h-vectors of the following simplicial complexes are log-concave:
- 1.
- The matroid complex of independent subsets of E. 相似文献
73.
It is known that an n-dimensional convex body, which is typical in the sense of Baire category, shows a simple, but highly non-intuitive curvature behaviour: at almost all of its boundary points, in the sense of measure, all curvatures are zero, but there is also a dense and uncountable set of boundary points at which all curvatures are infinite. The purpose of this paper is to find a counterpart to this phenomenon for typical convex bodies of given constant width. Such bodies cannot have zero curvatures. A main result says that for a typical n-dimensional convex body of constant width 1 (without loss of generality), at almost all boundary points, in the sense of measure, all curvatures are equal to 1. (In contrast, note that a ball of width 1 has radius 1/2, hence all its curvatures are equal to 2.) Since the property of constant width is linear with respect to Minkowski addition, the proof requires recourse to a linear curvature notion, which is provided by the tangential radii of curvature. 相似文献
74.
Daouda Ndiaye Maryame Sy Agns Pallier Sandra Même Isidro de Silva Sara Lacerda Aline M. Nonat Loïc J. Charbonnire va Tth 《Angewandte Chemie (International ed. in English)》2020,59(29):11958-11963
The search for more biocompatible alternatives to Gd3+‐based MRI agents, and the interest in 52Mn for PET imaging call for ligands that form inert Mn2+ chelates. Given the labile nature of Mn2+, high inertness is challenging to achieve. The strongly preorganized structure of the 2,4‐pyridyl‐disubstituted bispidol ligand L1 endows its Mn2+ complex with exceptional kinetic inertness. Indeed, MnL1 did not show any dissociation for 140 days in the presence of 50 equiv. of Zn2+ (37 °C, pH 6), while recently reported potential MRI agents MnPyC3A and MnPC2A‐EA have dissociation half‐lives of 0.285 h and 54.4 h under similar conditions. In addition, the relaxivity of MnL1 (4.28 mm ?1 s?1 at 25 °C, 20 MHz) is remarkable for a monohydrated, small Mn2+ chelate. In vivo MRI experiments in mice and determination of the tissue Mn content evidence rapid renal clearance of MnL1. Additionally, L1 could be radiolabeled with 52Mn and the complex revealed good stability in biological media. 相似文献
75.
76.
A subset S of a d-dimensional convex body K is extensive if S
∂K and for any p, q ∈ S the distance between p and q is at least one-half of the maximum length of chords of K parallel to the segment pq. In this paper we establish the general upper bound |S| ≤ 3
d
— 1. We also find an upper bound for a certain class of 3-polytopes, which leads to the determination of the maximum cardinalities
of extensive subsets and their extremal configurations for tetrahedra, octahedra and some other 3-polytopes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
77.
Let (X, B) be a Minkowski space (finite-dimensional Banach space) with unit ball B. Using a Minkowski definition of unit normal to a hypersurface, a Minkowski analogue of Euclidean divergence is defined. We show that the divergence theorem holds. Using the Minkowski divergence, a Minkowski Laplacian is defined. We prove that this Laplacian is a second-order, constant-coefficient, elliptic, differential operator. Furthermore, the symbol of this Laplacian is computed and used to associate a natural Euclidean structure with (X, B).Supported, in part, by NSERC Operating Grant #4066. 相似文献
78.
79.
80.
D. P. Tewari Awdhesh Kumar J. K. Sharma 《Applied Physics A: Materials Science & Processing》1977,14(2):225-227
A uniform electromagnetic wave of high power density, propagating in a collisional plasma gives rise to a modification in
temperature-dependent collision frequency and in turn induces a gradient in the complex refractive index of the medium. A
WKB solution of the problem predicts a backward propagating wave on account of the self-induced inhomogeneity. The amplitude
of the backward (i.e. reflected) wave increases with increasing power density of the wave. This is a volume nonlinear effect
and is appreciable for usually employed power densities. 相似文献