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991.
On Minimal Realization Over a Finite Chain Ring 总被引:1,自引:0,他引:1
Graham Norton 《Designs, Codes and Cryptography》1999,16(2):161-178
Let R be a finite chain ring, e.g. a Galois ring. We give a compact recursive formula for a minimal realization of a finite R-sequence. In particular, we show how to obtain a monic minimal polynomial and a rational approximation of a finite R-sequence. We also show how to solve the classical key equation of Algebraic Coding Theory over R. 相似文献
992.
Raffaele Vitolo 《Differential Geometry and its Applications》1999,10(3):1191-255
We consider two geometric formulations of Lagrangian formalism on fibred manifolds: Krupka's theory of finite order variational sequences, and Vinogradov's infinite order variational sequence associated with the
-spectral sequence. On one hand, we show that the direct limit of Krupka's variational bicomplex is a new infinite order variational bicomplex which yields a new infinite order variational sequence. On the other hand, by means of Vinogradov's
-spectral sequence, we provide a new finite order variational sequence whose direct limit turns out to be the Vinogradov's infinite order variational sequence. Finally, we provide an equivalence of the two finite order and infinite order variational sequences modulo the space of Euler-Lagrange morphisms. 相似文献
993.
We establish the first rate of convergence result for the class of derivative-free descent methods for solving complementarity problems. The algorithm considered here is based on the implicit Lagrangian reformulation [26, 35] of the nonlinear complementarity problem, and makes use of the descent direction proposed in [42], but employs a different Armijo-type linesearch rule. We show that in the strongly monotone case, the iterates generated by the method converge globally at a linear rate to the solution of the problem. 相似文献
994.
995.
张石生 《应用数学和力学(英文版)》1999,20(12):1310-1318
The purpose of this paper is to study the Mann and Ishikawa iterative approximation of solutions for m-accretive operator equations in Banach spaces. The results presented in this paper extend and improve some authors’ recent results. 相似文献
996.
The direct production of copper sulphate from copper ore is an important route to recover copper. The condition, however, is dependant on temperature and sulphatising environment. The oxidation of chalcopyrite in static air bed condition has been studied by TG/DTA and DSC techniques. The addition of catalysts, improved the sulphation by in-situ producing better condítions. The mutual effects of sulphides were further confirmed by studying the oxidation reaction on pure copper-iron sulphides and results so obtained were corroborated with X-ray diffractrograms. With only chalcopyrite a mass gain of 8% (TG) corresponding to copper sulphate formation was observed, in the temperature range 628–738 K. The TG plots showed respective mass gain of 14, 17 and 12% in presence of Fe2O3, Na2SO4 and FeSO4 with chalcopyrite in the wider temperature range 628–923 K. As such the cupric sulphide had a negligible tendency of sulphation, which increased with the addition of ferrous sulphide mixture under the temperature range studied. At higher temperature copper ferrite formation was found.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
997.
D. Sy C. Durand S. Hugot C. Savoye C. Swenberg M. Charlier M. Spotheim-Maurizot 《Theoretical chemistry accounts》1999,101(1-3):114-120
Sequence-dependent variations of DNA structure modulate radiation-induced strand breakage. Thiols reduce breakage by scavenging
damaging radiolytic OH
.
and repairing sugar radicals. As shown by sequencing gel electrophoresis, WR-1065 radioprotection is modulated by sequence,
whereas that of WR-151326, a larger thiol, is more evenly distributed. Molecular modelling was performed on complexes of a
53 bp oligonucleotide (belonging to a natural restriction fragment) with one molecule of WR-1065 or WR-151326. Energy minimised
structures exhibit a broadening of the minor groove of an AAATT motif upon WR-1065 binding, and a narrowing of the groove
upon WR-151326 binding. Consequently, the accessibility to OH˙ of H4′ (whose abstraction leads to strand breakage) increases near WR-1065, whereas it decreases near WR-151326. This modifies
locally the otherwise homogeneous radioprotection. The effect of WR-151326 strengthens the protection at all tested binding
sites, whereas that of WR-1065 diminishes it in some regions, in good agreement with the observed radioprotection distribution.
Received: 24 April 1998 / Accepted: 4 August 1998 / Published online: 11 November 1998 相似文献
998.
Neil Dummigan 《Compositio Mathematica》1999,119(2):111-132
Let X be the Fermat curve of degree q+1 over the field k of q2 elements, where q is some prime power. Considering the Jacobian J of X as a constant abelian variety over the function field k(X), we calculate the multiplicities, in subfactors of the Shafarevich–Tate group, of representations associated with the action on X of a finite unitary group. J is isogenous to a power of a supersingular elliptic curve E, the structure of whose Shafarevich–Tate group is also described. 相似文献
999.
设{Xn}是平稳序列,是X1(n),…,Xn(n)的顺序统计量.以Mn表示随机容量,Nn(k),k=1,…,s表示随机中心秩,本文在强混合条件下得到了序列(?)的极限分布. 相似文献
1000.
Eric Hughes Eric B. Brouwer Robin K. Harris 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1999,138(2):256
For compounds giving “crowded” 1-dimensional magic-angle-spinning spectra, information about the local atomic environment in the form of the chemical shift anisotropy (CSA) is sacrificed for high resolution of the less informative isotropic chemical shift. Magic-angle-turning (MAT) NMR pulse sequences preserve the CSA information by correlating it to the isotropic chemical shift in a 2-dimensional experiment. For low natural abundance nuclei such as 13C and 15N and under 1H heteronuclear dipolar decoupling conditions, the dominant NMR interaction is the chemical shift. For abundant nuclei such as 1H, 19F, and 31P, the homonuclear dipolar interaction becomes a significant contribution to the observed linewidth in both F1 and F2 dimensions. We incorporate MREV8 homonuclear multiple-pulse decoupling sequences into the MAT experiment to give a multiple-pulse MAT (MP-MAT) experiment in which the homonuclear dipolar interaction is suppressed while maintaining the chemical shift information. Extensive use of computer simulation using GAMMA has guided the pulse sequence development. In particular, we show how the MREV8 pulses can be incorporated into a quadrature-detected sequence such as MAT. The MP-MAT technique is demonstrated for a model two-site system containing a mixture of silver trifluoroacetate and calcium difluoride. The resolution in the isotropic evolution dimension is improved by faster sample spinning, shorter MREV8 cycle times in the evolution dimension, and modifications of the MAT component of the pulse sequence. 相似文献