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排序方式: 共有198条查询结果,搜索用时 15 毫秒
191.
192.
Two coordination polymers {[Co3L3(Me2NH)2]·(Me2NH)}n(1) and [CuL(bpy)]n(2)(L=2,2'-biphenyl dicarboxylate ion, bpy=4,4'-bipyridine) were obtained and characterized. Compound 1 was synthesised via solvothermal method, with the L ligands adopting syn-syn-μ2-η1:η1- and μ2-η2-coordination modes and Co(II) centers being linked to form a 1D coordination chain with trinuclear Co3 cluster as sub-units. Compound 2 was synthesized at room temperature, with the L ligand chelating the Cu(II) centers to form a 1D chain, which was further linked by the auxiliary 4,4'-bpy ligand to form a 3D coordination network. The results of variable temperature susceptibility studies reveal that there were ferromagnetic and antiferromagnetic interactions between the paramagnetic metal centers in compounds 1 and 2, respectively. 相似文献
193.
Two copper (II) α-Methacrylate complexes with benzimidazole, Cu[CH2 = C(CH3)-COO]2 (C3H6N2)2(1) and Cu2[CH2 = C(CH1)-COO]2(C3H6N2)2(2), have been prepared and characterized by elemental analyses, IR and electronic reflectance spectroscopies. ’The single
crystal X-ray diffraction study of the two complexes shows that complex 1 has a square planar configuration, while complex
2 has a binuclear cage structure. The crystal structural analyses show that both complexes 1 and 2 are monoclinic. with space
group p21/c,a = 0.924 16(8) nm,b = 1.233 02(13) nm,c = 0.989 1(3) nm,β = 91.912 (13),D
c = 1.386 g/cm3,Z=2,R = 0.033 9 for the former; anda = 0.905 7(2) nm,b = 2.252 1(5) nm,c = 1.623 5(4) nm,β = 90.11 (2),D
c = 1.411 g/cm3,Z = 4,R = 0.056 8, Cu-Cu = 0.266 21 nm for tin latter. Different structural types of complexes 1 and 2 were produced simultaneously
in the reaction of copper (II) α-methacrylate with benzimidazole in methanol solution. ’The forming mechanism of the complexes
has been summanzed.
Project supported by the national natural Science Foundation of China (Grant No. 29831010) and the Foundation of the State
Key Laboratory of Coordination Chemistry of Nanjing university. 相似文献
194.
Wu J Chen H Kwok W Guo R Zhou Z Yeung C Chan AS 《The Journal of organic chemistry》2002,67(22):7908-7910
A series of chiral trans-[RuCl(2)(dipyridylphosphine)(1,2-diamine)] complexes have been synthesized and characterized by NMR and single-crystal X-ray diffraction studies. These Ru complexes combined with (CH(3))(3)COK in 2-propanol formed a very effective catalyst system for the hydrogenation of a diverse range of simple aromatic ketones with high activity (substrate-to-catalyst ratio up to 100 000) and excellent enantioselectivity (up to >99.9%). The catalyst system was also found to be stable in solution even under a normal atmosphere. 相似文献
195.
沉管隧道横向地震响应分析是沉管隧道结构抗震设计的重点.根据沉管隧道的结构特点和接头剪力键的节点构造,建立了沉管隧道的多刚体-剪切铰-黏性阻尼铰多体动力学模型,并应用多体动力学中的离散时间传递矩阵法(multibody system discrete time transfer matrix method,MS-DT-TMM)建立了数学模型及表达式,同时编写Matlab程序进行求解实现.设定算例分别采用MS-DT-TMM和传统有限元法(finite element method,FEM)对沉管隧道横向地震响应进行对比分析,两者吻合较好,表明MS-DT-TMM应用于沉管隧道横向动力响应分析的可行性和有效性. 相似文献
196.
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198.
This paper deals with the following slightly subcritical Schrödinger equation: where is a nonnegative smooth function, , , , . Most of the previous works for the Schrödinger equations were mainly investigated for power-type nonlinearity. In this paper, we will study the case when the nonlinearity is a non-power nonlinearity. We show that, for ε small enough, there exists a family of single-peak solutions concentrating at the positive stable critical point of the potential . 相似文献