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991.
L. M. Pidzhakova 《Russian Mathematics (Iz VUZ)》2008,52(11):53-59
We consider multidimensional isoclinic three-webs with covariantly constant (with respect to the Chern connection) curvature and torsion tensors. It is proved that there exists a unique (up to an isotopy) isoclinic three-web with covariantly constant basic tensors.We find structure and finite equations of this web and consider some its properties. 相似文献
992.
993.
Giuseppina Barbieri Dikran Dikranjan Chiara Milan Hans Weber 《Mathematische Nachrichten》2008,281(7):930-950
For a recursively defined sequence u : = (un) of integers, we describe the subgroup tu (??) of the elements x of the circle group ?? satisfying limn unx = 0. More attention is dedicated to the sequences satisfying a secondorder recurrence relation. In this case, we show that the size and the free‐rank of tu (??) is determined by the asymptotic behaviour of the ratios qn = (un /un –1) and we extend previous results of G. Larcher, C. Kraaikamp, and P. Liardet obtained from continued fraction expansion. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
994.
A technique was developed for determining the longitudinal shear modulus of uniform diameter single fibers. A length of single
fiber suspended from one end and with a weight attached at the other end was used as a torsional pendulum. Its longitudinal
shear modulus can be experessed as a function of the frequency of oscillation of the torsional pendulum. Tests were conducted
on five different types of fibers: carbon, Kevlar 49, silicon carbide, K-glass fibers and G-glass fibers. 相似文献
995.
只有纯虚谱的Hamilton算子 总被引:1,自引:1,他引:0
刻画了一类无穷维Hamilton算子的谱的分布情况,并得到了无穷维Hamilton算子只有纯虚谱的充分条件.最后,构造出具体的例子以说明判别准则的有效性. 相似文献
996.
本文研究了R3中相交子流形的不变量.利用活动标架法,得出了一个类似的欧拉公式. 即两曲面交线的挠率可以用两曲面的测地挠率、法曲率及两曲面的夹角表示. 相似文献
997.
The authors establish a Cheeger-Müller type theorem for the complex valued analytic torsion introduced by Burghelea and Hailer for fiat vector bundles carrying nondegenerate symmetric bilinear forms. As a consequence, they prove the Burghelea-Haller conjecture in full generality, which gives an analytic interpretation of (the square of) the Turaev torsion. 相似文献
998.
E. A. Timoshenko 《Acta Appl Math》2005,85(1-3):297-303
This paper deals with the class of idempotent radicals defined by means of a tensor product. Their effect on Abelian groups is described. We also establish their connection with attracting modules.
Mathematics Subject Classification (2000) 18E40. 相似文献
999.
Philip C. Bulman Page Benjamin R. Buckley Colin M. Hayman Gerasimos A. Rassias Salem A. Talib 《Tetrahedron》2007,63(45):10991-10999
A number of enantiomerically pure 1,2-aminoalcohols containing tertiary nitrogen atoms bearing chiral substituents have been prepared by highly diastereoselective reductive ring cleavage of oxazolidines derived from ketones and pseudoephedrine or ephedrine. The ring cleavage occurs with retention of configuration. 相似文献
1000.
Alejandro D. Rey 《Rheologica Acta》2008,47(8):861-871
This paper develops and applies a linear viscoelastic model for bending and torsional modes of fluid membranes, based on the
nonlinear Cosserat surface fluid model. The linearized fluid membrane model in spherical and cylindrical geometries is shown
to decouple bending and torsional viscoelastic modes. It is found that solutions of the membrane viscoelastic model to small-amplitude
oscillatory bending and torsion allows for the measurement of the bending and the torsion viscosity. The model and its potential
in characterizing the bending and torsion viscoelasticity of membranes complements the on-going efforts to establish the role
of curvature in dissipative process of biological membranes. 相似文献