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61.
Let (X,0) be the germ of a normal space of dimension n+1 and let f be the germ at 0 of a holomorphic function on X. Assume both X and f have an isolated singularity at 0. Denote by J the image of the restriction map , where F is the Milnor fibre of f at 0. We prove that the canonical Hermitian form on , given by poles of order at in the meromorphic extension of , passes to the quotient by J and is non-degenerate on . We show that any non-zero element in J produces a “mass concentration” at the singularity which is related to a simple pole concentrated at for (in a non-na?ve sense). We conclude with an application to the asymptotic expansion of oscillatory integrals , for , when .
Received: 28 May 2001 / Published online: 26 April 2002 相似文献
62.
A.A. George Michael 《Topology and its Applications》2006,153(14):2591-2612
Edmonds showed that two free orientation preserving smooth actions φ1 and φ2 of a finite Abelian group G on a closed connected oriented smooth surface M are equivalent by an equivariant orientation preserving diffeomorphism iff they have the same bordism class [M,φ1]=[M,φ2] in the oriented bordism group Ω2(G) of the group G. In this paper, we compute the bordism class [M,φ] for any such action of G on M and we determine for a given M, the bordism classes in Ω2(G) that are representable by such actions of G on M. This will enable us to obtain a formula for the number of inequivalent such actions of G on M. We also determine the “weak” equivalence classes of such actions of G on M when all the p-Sylow subgroups of G are homocyclic (i.e. of the form n(Z/pαZ)). 相似文献
63.
64.
Dekel Tsur 《Discrete Applied Mathematics》2007,155(10):1275-1293
We study the following problem: given a tree G and a finite set of trees H, find a subset O of the edges of G such that G-O does not contain a subtree isomorphic to a tree from H, and O has minimum cardinality. We give sharp boundaries on the tractability of this problem: the problem is polynomial when all the trees in H have diameter at most 5, while it is NP-hard when all the trees in H have diameter at most 6. We also show that the problem is polynomial when every tree in H has at most one vertex with degree more than 2, while it is NP-hard when the trees in H can have two such vertices.The polynomial-time algorithms use a variation of a known technique for solving graph problems. While the standard technique is based on defining an equivalence relation on graphs, we define a quasiorder. This new variation might be useful for giving more efficient algorithm for other graph problems. 相似文献
65.
In this paper we prove the semialgebraic version of Palais' covering homotopy theorem, and use this to prove Bredon's covering mapping cylinder conjecture positively in the semialgebraic category. Bredon's conjecture was originally stated in the topological category, and a topological version of our semialgebraic proof of the conjecture answers the original topological conjecture for topological G-spaces over “simplicial” mapping cylinders. 相似文献
66.
A way of determining the flexibility of wood-pulp fibres is developed, which involves i) a precise measurement of the topology
of single-fibres by using a confocal laser scanning microscope and ii) the measurement of the elastic modulus of the fibres
by using a single-fibre fatigue cell. Reported in this paper are the initial results of tests carried out on black spruce
fibres, which have been subjected to three different levels of mechanical refining energy, namely ∼1100, 2300, and 3500 kWh/t.
It is found that the fibre flexibility rises significantly between the first and second energy levels, but it does not change
to the same degree between the second and third ones. The described procedure of measuring the flexibility of fibres may be
used to establish the appropriate refiner energy necessary for the production of a specific grade of paper.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 42, No. 1, pp. 115–128, January–February, 2006. 相似文献
67.
D. Ugolini M. -H. Tuilier J. Eitle S. Schelz J. Q. Wang P. Oelhafen 《Applied Physics A: Materials Science & Processing》1990,51(6):526-536
Polymeric styrene films with thicknesses ranging from about one nm up to a few m have been deposited by means of a direct ion beam deposition (IBD) technique. The deposition energy, which can be chosen independently of the parameters which govern the plasma conditions, has been varied between few eV and 1000 eV. The correlation between the deposition parameters and the resulting film properties in terms of the electronic structure is discussed. The in situ characterization by electron spectroscopy has proved to be a very useful characterization method and ultraviolet photoelectron spectroscopy in particular revealed an extremely high sensitivity to structural differences in the deposited films. The polymeric films have also been characterized by scanning electron microscopy and optical spectroscopy. These techniques have also served to compare films prepared by the direct IBD technique with films obtained by standard rf plasma polymerization (RFPP) in a tubular reactor. Significant differences have been found which are dependent on the deposition parameters; these are discussed in detail.Department of Chemical Engineering, Beijing Institute of Technology, P.O. Box 327 Beijing, 100081 Beijing, P.R. China 相似文献
68.
晶化温度对中孔分子筛(M41S)结构转变的影响 总被引:11,自引:6,他引:11
在低表面活性剂浓度及低表面活性剂与氧化硅比的条件下,研究了十六烷基三甲基溴化铵-硅酸钠体系中晶化温度对中孔分子筛M41S材料结构转变的影响。结果有,晶化温度提高至135℃改变了原六方晶相MCM-41的结构,晶化温度提高到150℃后,中孔结构六方MCM-41晶格转变为变不稳定的层状相, 相似文献
69.
70.