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51.
Using multiplication algebras we introduce actor crossed modules of commutative algebras and use it to generalise some aspects from commutative algebras to crossed modules of commutative algebras. This is applied to the Peiffer pairings in the Moore complex of a simplicial commutative algebra. 相似文献
52.
Simion Breaz 《Czechoslovak Mathematical Journal》2003,53(2):479-489
We present general properties for almost-flat modules and we prove that a self-small right module is almost flat as a left module over its endomorphism ring if and only if the class of g-static modules is closed under the kernels. 相似文献
53.
We investigate the minimal number of generators and the depth of divisorial ideals over normal semigroup rings. Such ideals are defined by the inhomogeneous systems of linear inequalities associated with the support hyperplanes of the semigroup. The main result is that for every bound C there exist, up to isomorphism, only finitely many divisorial ideals I such that (I)C. It follows that there exist only finitely many Cohen–Macaulay divisor classes. Moreover, we determine the minimal depth of all divisorial ideals and the behaviour of and depth in arithmetic progressions in the divisor class group.The results are generalized to more general systems of linear inequalities whose homogeneous versions define the semigroup in a not necessarily irredundant way. The ideals arising this way can also be considered as defined by the nonnegative solutions of an inhomogeneous system of linear diophantine equations.We also give a more ring-theoretic approach to the theorem on minimal number of generators of divisorial ideals: it turns out to be a special instance of a theorem on the growth of multigraded Hilbert functions. 相似文献
54.
BRST resolution is studied for the principally graded Wakimoto module of
recently found in math.QA/0005203. The submodule structure is completely determined and irreducible representations can be obtained as the zero-th cohomology group. 相似文献
55.
Stuart A. Steinberg 《Czechoslovak Mathematical Journal》2001,51(2):387-394
In an -group M with an appropriate operator set it is shown that the -value set (M) can be embedded in the value set (M). This embedding is an isomorphism if and only if each convex -subgroup is an -subgroup. If (M) has a.c.c. and M is either representable or finitely valued, then the two value sets are identical. More generally, these results hold for two related operator sets 1 and 2 and the corresponding -value sets
and
. If R is a unital -ring, then each unital -module over R is an f-module and has
exactly when R is an f-ring in which 1 is a strong order unit. 相似文献
56.
Extensions of crossed modules in Lie algebras with abelian kernel are studied, particularly backward and forward induced extensions and related properties. The set Opext((U, Q, ), (R, K, )) of congruence classes of extensions of (R, K, ) by (U, Q, ) is endowed with a K-vector space structure. This K-vector space appears in a five-term natural and exact sequence associated with an extension of crossed modules.2000 Mathematics Subject Classification: 17B56, 17B99, 18G99 相似文献
57.
Ralf Kemper 《Proceedings of the American Mathematical Society》2000,128(3):709-712
It is an open question as to whether every left coherent ring satisfying the intersection property for finitely generated left ideals of is a right-product-trace-ring or not. is a right-product-trace-ring iff every product of trace-right--modules (= universally torsionless-right--modules) is a trace-right--module. This question is shown to have a negative answer. Furthermore, looking at all valuation domains, the complete product-trace-rings, the product-trace-rings and the product-content-rings are characterized.
58.
利用自行研制的空心微球耐外压装置和充气装置,测试了目前激光惯性约束聚变实验打靶使用的空心玻璃微球耐内压能力和耐外压能力。空心玻璃微球采用液滴法制备,直径为180~250 mm、壁厚为0.8~4.0 mm。理论计算表明,当微球纵横比超过90时,耐外压能力与球壳材料的杨氏模量有关,由此测量得到的空心玻璃微球杨氏模量为55~75 GPa。玻璃微球的耐内压能力主要与球壳材料的抗拉强度有关,实验测量得到的玻璃微球抗拉强度为90~140 MPa。 相似文献
59.
The iron nodule DS-S revealed the concentrations of Ni, Co, Ga, Ge, As, Sb, P, S, many trace and rare earth elements, Fe (> 93 wt.%), and 2 wt.% silicates. The plotting of Ga, Ge, Cr, Cu, As, Au, W, and Ir-concentrations vs. Ni/Co in the classes (groups) IIAB, IIIAB, IVA, ungrouped (ung), NBS 809B steel (st), and DS-S, confirmed the meteoritic origin for DS-S. Magnetite-hematite resulted from oxidation during the melting/solidification process of the original meteorite across the atmosphere. The silicates suggested the presence of Ca-rich plagioclase, and traces of opx, cpx, and/or olivine which explained the low concentrations of Ni-Co. The plotting of Ga/Ge vs. Ni/Co; Ni/Co, Ga vs. P; and Ni/Co, Ga/Ge vs. As revealed the affinity of the DS-S nodule with the ungrouped Bellsbank trio. The compositional homogeneity in the DS-S nodule was probably due to O-fugacity. The conformable REE-graphs, for chondrite and DS-S, and the presence of silicates with the same phases suggested a mesosideritic origin for DS-S. 相似文献
60.