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991.
The problem of differential equation systems admitting a nonlinear superposition principle is analyzed from a geometric perspective. We show how it is possible to reduce the problem of finding the general solution of such a differential equation system defined by a Lie group G to a pair of simpler problems, one in a subgroup H and the other on a homogeneous space. The theory is illustrated with several examples and applications. 相似文献
992.
Kestenband proved in [12] that there are only seven pairwise non‐isomorphic Hermitian intersections in the desarguesian projective plane PG(2, q) of square order q. His classification is based on the study of the minimal polynomials of the matrices associated with the curves and leads to results of purely combinatorial nature: in fact, two Hermitian intersections from the same class might not be projectively equivalent in PG(2, q) and might have different collineation groups. The projective classification of Hermitian intersections in PG(2, q) is the main goal in this paper. It turns out that each of Kestenband's classes consists of projectively equivalent Hermitian intersections. A complete classification of the linear collineation groups preserving a Hermitian intersection is also given. © 2001 John Wiley & Sons, Inc. J Combin Designs 9: 445–459, 2001 相似文献
993.
994.
A new kind of soluble structure‐ordered ladder‐like polysilsesquioxane with reactive side‐chain 2‐(4‐chloromethyl phenyl) ethyl groups ( L ) was first synthesized by stepwise coupling polymerization. The monomer, 2‐(4‐chloromethyl phenyl) ethyltrichlorosilane ( M ), was synthesized successfully by hydrosilylation reaction with dicyclopentadienylplatinum(II) chloride (Cp2PtCl2) catalyst. Monomer and polymer structures were characterized by FT‐IR, 1H‐NMR, 13C‐NMR, 29Si‐NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vapor pressure osmometry (VPO) and X‐ray diffraction (XRD). This novel reactive ladder‐like polymer has promise potential applications as initiator for atom transfer radical polymerization, and as precursor for a variety of advanced functional polymers. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
995.
V. A. Krasnov 《Mathematical Notes》2000,67(2):168-175
The map of the Brauer group of a real algebraic surface to the invariant part of the Brauer group of its complexification
is studied. In this study, the real cycle map of the Picard group is used.
Translated fromMatematicheskie Zametki, Vol. 67, No. 2, pp. 211–220, February, 2000. 相似文献
996.
S. V. Lyudkovskii 《Mathematical Notes》2000,68(1):90-96
Relations between the measurability and continuity of algebraic automorphisms of topological groups depending on the types
of groups are examined. Various cases are considered and theorems on the continuity of measurable automorphisms are proved;
for instance, such theorems are proved for separable locally compact groups and automorphisms measurable with respect to nonnegative
Haar measures. On the other hand, examples of nonmetrizable nonseparable compact groups with Haar measures and of non-locally-compact
separable metrizable groups with measures μ quasi-invariant with respect to dense subgroups admittings μ-measurable discontinous
automorphisms are given.
Translated fromMatenmaticheskie Zametki, Vol. 68, No. 1, pp. 105–112, July, 2000.
An erratum to this article can be found online at . 相似文献
997.
V. A. Krasnov 《Mathematical Notes》2000,67(3):296-300
The Brauer group of a noncomplete real algebraic surface is calculated. The calculations make use of equivariant cohomology.
The resulting formula is similar to the formula for a complete surface, but the proof is substantially different.
Translated fromMatematicheskie Zametki, Vol. 67, No. 3, pp. 355–359, March, 2000. 相似文献
998.
By a theorem of L. Rédei if a finite abelian group is a direct product of its subsets such that each subset has a prime number of elements and contains the identity element of the group, then at least one of the factors must be a subgroup. The content of this paper is that this result holds for certain infinite abelian groups, too. Namely, for groups that are direct products of finitely many Prüferian groups and finite cyclic groups of prime power order, belonging to pairwise distinct primes. 相似文献
999.
城市综合实力增长的比较 总被引:7,自引:1,他引:6
本文基于多个总体的主成分分析方法,对城市综合实力增长的比较进行一些探索性的研究。对我国十八个大城市1994年、1995年和1996年的八个指标用多个总体的主成分分析方法进行分析,通过检验和计算,得到这三个总体的公共主成分子空间。取公共主成分子空间的一正交基作为这三个总体的新的主成分PRIN1的系数,此主成分即表示城市综合实力。计算出各城市任意两年间的综合实力差值,以此作为城市综合实力增长的度量,对城市综合实力增长再作主成分分析,即得到有效的城市综合实力增长的比较方法 相似文献
1000.
朱月萍 《数学物理学报(A辑)》2000,20(Z1):616-624
该文给出了Vilenkin群上加权局部Hardy空间的定义,它的原子分解及对偶性质,并且研究了一类卷积算子在其上的有界性. 相似文献