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91.
92.
Cao‐Yuan Niu Xian‐Fu Zheng Ling‐Ling Bai Xiao‐Ling Wu Chun‐Hong Kou 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(9):m305-m307
This study presents new coordinating modes of a Schiff base with three coordinating groups and an interesting two‐dimensional framework based on two types of constructing units. In the title compound, {[Ag(C14H10N4O)]ClO4}n, the AgI ion is coordinated by three N atoms and one O atom from three different N′‐(4‐cyanobenzylidene)isonicotinohydrazide (L) ligands, forming a primary distorted square‐planar coordination geometry. Two ligands each bridge two metal centres through one carbonitrile N atom in a monodentate mode and the hydrazide N and O atoms in a bidentate mode to form a small centrosymmetric (2+2)‐Ag2L2 ring as a principal constructing unit. The pyridyl N atoms from four ligands in four of these small rings coordinate to Ag atoms in adjacent rings to form a large hexanuclear silver grid. A two‐dimensional framework of rectangular grids is constructed from these small rings and large grids. Two perchlorate anions are located in each large grid and are bound to the grid by N—H...O hydrogen bonding. Crosslinking between the layers is achieved through long Ag...O interactions between the perchlorate anions and Ag atoms in adjacent layers. 相似文献
93.
94.
Ai-Li Cui Guo-Xing Feng Ya-Fan Zhao Hui-Zhong Kou Hong Li Guang-Hua Zhu Ho-Soon Hwang Hee-Chang Oh Young-Jin Kwon Doo-Chul Lee 《Electrochemistry communications》2009,11(2):409-412
Electrochemical oxidation of graphite anode in deionized water at galvanostatic mode is investigated. It is found that mellitic acid and graphite oxide colloid (>20 nm) are coexisted as main products, as identified by XRD and TEM, FTIR and XPS. They can be separated successfully through several procedures. A few amounts of graphene and graphene rolls are also appeared as co-products. 相似文献
95.
对ISO/IEC17025-1999和ISO/IEC指南25-1990进行了比较,分析了ISO/IEC17025-1999的显著变化,提出了由ISO/IEC指南25-1990质量体系向ISO/IEC17025-1999质量体系过渡的措施。 相似文献
96.
In this paper, we present some variants of Cauchy's method for solving non-linear equations. Analysis of convergence shows that the methods have fourth-order convergence. Per iteration the new methods cost almost the same as Cauchy's method. Numerical results show that the methods can compete with Cauchy's method. 相似文献
97.
This paper introduces a novel niching scheme called the q-nearest neighbors replacement (q-NNR) method in the framework of the steady-state GAs (SSGAs) for solving binary multimodal optimization problems. A detailed
comparison of the main niching approaches are presented first. The niching paradigm and difference of the selection-recombination
genetic algorithms (GAs) and the recombination-replacement SSGAs are discussed. Then the q-NNR is developed by adopting special replacement policies based on the SSGAs; a Boltzmann scheme for dynamically sizing the
nearest neighbors set is designed to achieve a speed-up and control the proportion of individuals adapted to different niches.
Finally, experiments are carried out on a set of test functions characterized by deception, epistasis, symmetry and multimodality.
The results are satisfactory and illustrate the effectivity and efficiency of the proposed niching method. 相似文献
98.
99.
应用量子化学方法 B3LYP/6-311+G(d,p),对气相团簇M(CH3OH)1~4(M=Be2+/Mg2+/Ca2+)的结构、能量进行计算,采用HF/STO-3G方法对电荷分布进行研究.结果表明,甲醇分子通过O原子配位于金属离子形成最稳定结构,金属与CH3OH中的O的距离由大到小为RCa-ORMg-ORBe-O,而结合能由大到小依次为Be2+Mg2+Ca2+.随着甲醇分子数n的增加,金属离子与O的距离RM-O逐渐增大,总结合能逐渐增大,连续结合能逐渐减小,金属离子所带的正电荷在逐渐减小,对于相同配位数n,Be2+的电荷转移量最大,Ca2+的电荷转移量最小;甲醇分子中各原子所得正电荷的大小顺序为H(-HO)H(-H3C)CO. 相似文献
100.
可扩展的冲击—接触并行计算研究 总被引:1,自引:0,他引:1
冲击—接触计算模型在汽车碰撞、金属成型等的模拟计算中有着广泛的应用,鉴于冲击—接触计算过程复杂和计算量大,本文在分布式可扩展的并行计算平台上,设计并实现了冲击—接触的并行计算。算例证明,计算平台稳定可靠,算法简单实用,且具有较好的并行效率和可扩展性。 相似文献