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21.
In this article, we consider the factorization of a sparse nonsymmetric matrix using Gaussian elimination with partial pivoting on a multiprocessor having a globally-shared memory. The parallel algorithm makes use of a static data structure developed by George, Liu and Ng in [17]. Some numerical experiments on a Sequent Balance 8000 are presented to demonstrate the efficiency of the parallel implementation.Research supported in part by the Applied Mathematical Sciences Research Program, Office of Energy Research, U.S. Department of Energy under contract DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc. 相似文献
22.
23.
把一个由GaAs光电导开关和激光腔中的普克尔盒组成的正反馈回路,用于YAG激光器中,选单纵模和调Q,获得了稳定可靠的单纵模调Q脉冲. 相似文献
24.
合成了两个由胍盐(G)和4,4’—苯醚二磺酸(PEDS)为主体框架所形成的主— 客体包合物,分别为[(CH6N3)]2[(C12H8O7S2)]·MeOH·2(H20)(1)和[(CH6N3)]2[ (C12H8O7S2)]·(C10H8)(2).两个化合物都是以P—1空间群结晶,晶胞参数分别为 :1a=0.7509(4)nm,b=1.2113(6)nm,c=1.5936(8)nm,a=102.636(10)° ,β=102.703(11)°,γ=91.318(10)°;2a=0.75409(3)nm,b=1.21584 (5)nm,c=3.09376(14)nm,a=81.506(2)°,β=89.669(2)°,γ=88. 890(2)°。在这两个晶体结构中,G和PEDS通过氢键形成了双夹层—双柱子的主体 框架,客体分子被包合在平行于a轴方向的晶格空间.这种双夹层—双柱子的主体 框架在由胍盐(G)和有机二磺酸(S)体系所形成的、具有通道结构的主体框架中是较 为少见的. 相似文献
25.
NG S. K.; CAINES P. E.; CHEN H. F. 《IMA Journal of Mathematical Control and Information》1984,1(2):129-140
Following the procedure described by Elworthy (1982) and Ikeda& Watanabe (1981) we construct the solution of stochasticdifferential equations (SDEs) in manifolds. We take such SDEsto describe parametrized completely observed stochastic systemsand manifold-valued state processes. The likelihood functionfor the system parameter is computed by two methods: the firstapplies to the case of parallelizable manifolds; the secondapplies to the general case, here the solution of the systemSDE is constructed in the orthonormal frame bundle of the manifold.Two examples are given. 相似文献
26.
1 INTRODUCTION Much attention has been paid to 1D, 2D and 3D coordination polymers because they can meet the need of functional materials with desired structures and properties[1~5]. One strategy in the design and synthesis of coordination architectures is the buil- ding-block approach. Commonly, bi- or multidentate organic ligands containing N[6, 7] or O[8, 9] atoms have ever been used in the construction. In our cur- rent work, we have selected melamine ligand as the main building bl… 相似文献
27.
The space groups of 244 crystal structures originally reported as P-1 are revised to space groups of higher symmetry. The largest number involves revisions to P2/c and C2/c. 相似文献
28.
NG Seik Weng 《结构化学》2005,24(1)
The space group of [(H2O)(C3H4N2)(O2CCH=CHCO2Zn)]n, which was originally described in the acentric Pc space group (Liu et al., Chin. J. Struct. Chem. 2004, 23, 160~163), is re-described in the centric P21/c space group.The crystal structure of (H2O)(C3H4N2)O2C-CH=CHCO2Zn was refined in the acentric Pc space group on 266 variables to R = 0.037 for the 1926 of the 2067 obeying the I > 2σ criterion[1]. The structure is better described in the centric P21/c space group (Table 1) as the two indepen-dent formula units are related by a center of symmetry. The 21 screw axis is must be pre-sent, as noted from the systematically absent 0k0 (k = 2n + 1) reflections in the 3302 reflections that were simulated[2, 3] from the published cell dimensions and atomic coordinates. Crystallo-graphica[4] estimates the hemisphere of reflections to be 3302, so that only a little more than the minimum monoclinic data must have been collec-ted in the study. A revision from Pc to P21/c is not particularly common[5] as the P21/c space group is uniquely determined from systematic absences. The polymeric chain propagates linearly along the c-axis of the unit cell (Fig. 1). 相似文献
29.
LANGLEY J. K. 《中国科学 数学(英文版)》2010,(3)
We determine all real meromorphic functions f in the plane such that f has finitely many zeros, the poles of f have bounded multiplicities, and f and F have finitely many non-real zeros, where F is a linear differential polynomial given by F = f (k) +Σk-1j=0ajf(j) , in which k≥2 and the coefficients aj are real numbers with a0≠0. 相似文献
30.