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51.
本文对外代数上复杂度为2的不可分解循环Koszul模M的极小投射分解进行了分析,构造出了基映射对应的矩阵的一种标准形式,进而刻划出了其合冲ΩM的滤链结构.  相似文献   
52.
Braverman and Finkelberg have recently proposed a conjectural analogue of the geometric Satake isomorphism for untwisted affine Kac–Moody groups. As part of their model, they conjecture that (at dominant weights) Lusztig's q-analog of weight multiplicity is equal to the Poincare series of the principal nilpotent filtration of the weight space, as occurs in the finite-dimensional case. We show that the conjectured equality holds for all affine Kac–Moody algebras if the principal nilpotent filtration is replaced by the principal Heisenberg filtration. The main body of the proof is a Lie algebra cohomology vanishing result. We also give an example to show that the Poincare series of the principal nilpotent filtration is not always equal to the q-analog of weight multiplicity. Finally, we give some partial results for indefinite Kac–Moody algebras.  相似文献   
53.
陶瓷过滤器高温除尘技术的研究进展   总被引:2,自引:0,他引:2  
对陶瓷过滤元件及结构、滤饼的作用和架桥、过滤器故障安全(CPP)系统及陶瓷过滤器高温气体净化一体化技术等几个方面进行了评述,总结了陶瓷过滤器存在着过滤管破裂、清灰效率下降、管板和器壁的连接及脉冲阀的长期稳定性等几个问题,指出新型陶瓷材料的研究和陶瓷过滤器高温气体净化一体化技术是陶瓷过滤器今后的研究方向.  相似文献   
54.
Hélène Esnault 《K-Theory》1994,8(5):483-497
On a smooth algebraic complex varietyX, we show that the classes of a flat bundle, which is trivialized on a finite cover ofX, with values in the odd-dimensional cohomology of the underlying complex manifold with / (i), are living in the bottom part of Grothendieck's coniveau filtration. This answers positively when the basis is smooth complex a question of Bruno Kahn [K-Theory (1992), conjecture 2].  相似文献   
55.
The title refers to the nilcommutative or NC-schemes introduced by M. Kapranov in Noncommutative Geometry Based on Commutator Expansions, J. Reine Angew. Math 505 (1998) 73–118. The latter are noncommutative nilpotent thickenings of commutative schemes. We also consider the parallel theory of nil-Poisson or NP-schemes, which are nilpotent thickenings of commutative schemes in the category of Poisson schemes. We study several variants of de Rham cohomology for NC- and NP-schemes. The variants include nilcommutative and nil-Poisson versions of the de Rham complex as well as of the cohomology of the infinitesimal site introduced by Grothendieck in Crystals and the de Rham Cohomology of Schemes, Dix exposés sur la cohomologie des schémas, Masson, Paris (1968), pp. 306–358. It turns out that each of these noncommutative variants admits a kind of Hodge decomposition which allows one to express the cohomology groups of a noncommutative scheme Y as a sum of copies of the usual (de Rham, infinitesimal) cohomology groups of the underlying commutative scheme X (Theorems 6.1, 6.4, 6.7). As a byproduct we obtain new proofs for classical results of Grothendieck (Corollary 6.2) and of Feigin and Tsygan (Corollary 6.8) on the relation between de Rham and infinitesimal cohomology and between the latter and periodic cyclic homology.  相似文献   
56.
Let R be a (not necessarily Noetherian) commutative ring and let M be a (not necessarily finitely generated) R-module. We characterize the modules with only finitely many weakly associated primes as those modules M admitting a chain 0 = M 0 M 1 ... M n = M of submodules together with prime ideals p1, p2,...,p n such that the set of weakly associated primes of M i /M i-1 is equal to {p i } for all 1 i n. Let M = gra(M) = n0a n M/a n+1 M be the corresponding graded module over the graded ring R = gra(R) = n0a n /a n+1. It is shown that the union of the set of weakly associated primes of.....  相似文献   
57.
Abstract

Let A be a commutative ring with identity, let X, Y be indeterminates and let F(X,Y), G(X, Y) ∈ A[X, Y] be homogeneous. Then the pair F(X, Y), G(X, Y) is said to be radical preserving with respect to A if Rad((F(x, y), G(x, y))R) = Rad((x,y)R) for each A-algebra R and each pair of elements x, y in R. It is shown that infinite sequences of pairwise radical preserving polynomials can be obtained by homogenizing cyclotomic polynomials, and that under suitable conditions on a ?-graded ring A these can be used to produce an infinite set of homogeneous prime ideals between two given homogeneous prime ideals P ? Q of A such that ht(Q/P) = 2.  相似文献   
58.
Semisimple Representations of Quivers in Characteristic p   总被引:1,自引:0,他引:1  
We prove that the results of Le Bruyn and Procesi on the varieties parameterizing semisimple representations of quivers hold over an algebraically closed base field of arbitrary characteristic.  相似文献   
59.
为研究卷烟纸、成型纸、接装纸及嘴棒组合搭配对"中式卷烟"焦油量、烟气烟碱量、烟气水分、烟气一氧化碳量及过滤效率的影响,尝试采用L_(27)(3~(13))裂区正交设计方法对RR卷烟进行在线试验和取样.检测结果经过直观分析、方差分析及贡献率分析,结果表明:嘴棒长度、吸阻及接装纸透气度是影响试验指标的高度显著因素及重要因素.所以重点对嘴棒长度、吸阻及接装纸透气度进行调整和控制,可以很好地实现卷烟产品的质量控制,减少产品质量波动,降低产品成本.使用该方法可快捷、高效、经济、准确地寻找并确定卷烟材料多因素对卷烟主流烟气量及过滤效率的影响规律及卷烟产品的材料搭配优化方案.从而实现卷烟产品材料搭配精益化,满足烟草企业的实际需求.  相似文献   
60.
This article studies the theory of discrete-time backward stochastic differential equations (also called BSDEs) with a random terminal time, which is not a stopping time. We follow Cohen and Elliott [2 Cohen , S.N. , and Elliott , R.J. 2010 . A general theory of finite state backward stochastic difference equations . Stochastic Processes and Their Applications 120 ( 4 ): 442466 .[Crossref], [Web of Science ®] [Google Scholar]] and consider a reference filtration generated by a general discrete-time finite-state process. The martingale representation theorem for essentially bounded martingales under progressively enlarged filtration is established. Then we prove the existence and uniqueness theorem of BSDEs under enlarged filtration using some weak assumptions of the driver. We also present conditions for a comparison theorem. Applications to nonlinear expectations and optimal design of dynamic default risk are explored.  相似文献   
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