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51.
Explicit examples of finite subgroups of the group of homotopy classes of self-homotopy equivalences of some flat Riemannian manifolds which cannot be lifted to effective actions are given. It is also shown that no finite subgroups of the kernel of π0(Homeo(M))→Out π1(M) can be lifted back to Homeo(M), for a large class of flat manifolds M. Some results of an earlier paper by the authors are refined and related to recent work of R. Schoen and S.T. Yau. 相似文献
52.
杨爱珍 《应用数学与计算数学学报》1998,12(2):39-45
本文不仅给出一种构造局部性好的正交小波基的方法,并且给出了构造各种优良性质的正交小波基的一般思想方法。其特点:使构造的小波母函数有具体的表达式,既有较好的光滑性,又有很好的局部性,并且其收敛速度与│t│~(-(3k 1))同阶,其中k为任意自然数。这种方法不需要每次重新构造函数,只要改变k的值,就能满足不同实际问题的需要。 相似文献
53.
Let G be a locally compact group with a fixed right Haar measure andX a separable Banach space. LetL
p
(G, X) be the space of X-valued measurable functions whose norm-functions are in the usualL
p
. A left multiplier ofL
p
(G, X) is a bounded linear operator onB
p
(G, X) which commutes with all left translations. We use the characterization of isometries ofL
p
(G, X) onto itself to characterize the isometric, invertible, left multipliers ofL
p
(G, X) for 1 ≤p ∞,p ≠ 2, under the assumption thatX is not thel
p
-direct sum of two non-zero subspaces. In fact we prove that ifT is an isometric left multiplier ofL
p
(G, X) onto itself then there existsa y ∃ G and an isometryU ofX onto itself such thatTf(x) = U
(R
y
f)(x). As an application, we determine the isometric left multipliers of L1 ∩L
p
(G, X) and L1 ∩C
0
(G, X) whereG is non-compact andX is not the lp-direct sum of two non-zero subspaces. If G is a locally compact abelian group andH is a separable Hubert space, we define
where г is the dual group of G. We characterize the isometric, invertible, left multipliers ofA
p
(G, H), provided G is non-compact. Finally, we use the characterization of isometries ofC(G, X) for G compact to determine the isometric left multipliers ofC(G, X) providedX
*
is strictly convex. 相似文献
54.
D. I. Mirzai T. M. Guliev V. N. Akhmedov A. A. Isirikyan 《Russian Chemical Bulletin》1998,47(2):352-354
The ammonium form of natural zeolite, natrolite, obtained by vapor phase ion exchange is similar to calcium-containing zeolites
of the natrolite group in its de- and rehydration characteristics and the heats of immersion in water. The adsorption capacity
and the heat of immersion in water are maximum after evacuation of the zeolite at 200 °C. The irreversible sintering of NH4 natrolite occurs above 200 °C (up to 45% at 500 °C), accompanied by the formation of hydroxyl groups.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 359–361, February, 1998. 相似文献
55.
Let Möb(Sn+1) denote the Möbius transformation group of Sn+1. A hypersurface f:Mn → Sn+1 is called a Möbius homogeneous hypersurface, if there exists a subgroup G ? Möb(Sn+1) such that the orbit G(p)={φ(p)|φ ∈ G}=f(Mn), p ∈ f(Mn). In this paper, we classify the Möbius homogeneous hypersurfaces in Sn+1 with at most one simple principal curvature up to a Möbius transformation. 相似文献
56.
Osamu Hatori Takeshi Miura Hiroyuki Takagi 《Proceedings of the American Mathematical Society》2006,134(10):2923-2930
Let be a surjective mapping from a uniform algebra on a compact Hausdorff space onto a uniform algebra on a compact Hausdorff space . Suppose that holds for every . Then we have that is an almost isometric isomorphism, which is a generalization of results of Molnár (2002) and Rao and Roy (2005).
57.
In a given Kähler manifold (M,J) we introduce the notion of Kähler Frenet curves, which is closely related to the complex structure J of M. Using the notion of such curves, we characterize totally geodesic Kähler immersions of M into an ambient Kähler manifold and totally geodesic immersions of M into an ambient real space form of constant sectional curvature . 相似文献
58.
Interface reactions and film features of AZ91D magnesium alloy in pickling, activation and zinc immersion solutions have been investigated. The surface morphologies of the specimens were observed with scanning electron microscope (SEM). Electrochemical behaviors of AZ91D magnesium alloy in the baths of pickling, activation and zinc immersion were analyzed based on the open circuit potential (OCP) - time curves in various solutions. The results show that the corrosive rate in HNO3 + CrO3 or HNO3 + H3PO4 pickling solution was more rapid than in KMnO4 pickling-activation solution. Both α phase and β phase of the substrates were uniformly corroded in HNO3 + CrO3 or HNO3 + H3PO4 pickling solution, the coarse surface can augment the mechanical occlusive force between the subsequent coatings and the substrates, so coatings with good adhesion can be obtained. In HF activation solution, the chromic compound formed via HNO3 + CrO3 pickling was removed and a compact MgF2 film was formed on the substrate surface. In K4P2O7 activation solution, the corrosion products formed via HNO3 + H3PO4 pickling were removed, a new thin film of oxides and hydroxides was formed on the substrate surface. In KMnO4 pickling-activation solution, a film of manganic oxides and phosphates was adhered on the substrate surface. Zinc film was symmetrically produced via K4P2O7 activation or KMnO4 pickling-activation, so it was good interlayer for Ni or Cu electroplating. Asymmetrical zinc film was produced because the MgF2 film obtained in the HF activation solution had strong adhesive attraction and it was not suitable for interlayer for electroplating. However, the substrate containing compact MgF2 film without zinc immersion was fit for direct electroless Ni-P plating. 相似文献
59.
We get the characterizations of the family of all nonnegative,subadditive,β-absolutely homogeneous and continuous functionals defined on X,when the β-normed space X contains an asymptotically isometric copy of lβ.Moreover,it is proved that if a closed bounded β-convex subset K of a β-normed space contains an asymptotically isometric lβ-basis,then K contains a closed β-convex subset C which fails the fixed point property. 相似文献
60.
On Linearly Isometric Extensions for 1-Lipschitz Mappings Between Unit Spheres of ALP-spaces (p 〉 2)
In this paper, we show that if Vo is a 1-Lipschitz mapping between unit spheres of two ALP-spaces with p 〉 2 and -Vo(S1(LP)) C Vo(S1(LP)), then V0 can be extended to a linear isometry defined on the whole space. If 1 〈 p 〈 2 and Vo is an "anti-l-Lipschitz" mapping, then Vo can also be linearly and isometrically extended. 相似文献