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51.
The butadienyl moiety in the title compound is bound to both cage-boron and rhenium vertices, and arises from coupling of two alkyne molecules at the rhenium centre, unprecedented in metallacarbaborane chemistry. 相似文献
52.
Hong Li Yushu Liu Shaowu Zhang 《International Journal of Infrared and Millimeter Waves》2000,21(5):837-844
Soliton propagation in fiber with randomly varying birefringence is studied by using self-companying operator method. It is shown that randomly varying birefringence leads to time jitters increasing with transmission distance, and disrupts the stability of soliton transmission. The fluctuation of time jitters is stochastic, and nonlinear gain is introduced to remove the influence. 相似文献
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The main purpose of this work is to present a better bound than the recent result given by Zhang [Linear Multilinear Algebra. 2015;63:2511–2517]. 相似文献
55.
How-Ghee Ang Siau-Gek Ang Shaowu Du Boonhwa Sow 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The reaction of (CF3)2P-P(CF3)2 with [Ru3(CO)12] yielded compounds : [Ru14(CO)13{μ-P(CF3)2)2] (1), [Ru4(CO)14{μ-P(CF3)2}2] (2), and [Ru4(CO)11{μ-P(CF3)2}4] (3); reaction with [μ-H)4Ru4(CO)12] yielded (1) and [(μ-H)3Ru4(CO)12{μ-P(CF3)2}] (4). The reaction of (CF3)2PH with [Ru3(CO)12] yielded compounds (1) and (4) and compounds (1) and (2) using cluster : ligand ratios of 1:1 and 1:2 respectively. All the compounds have been characterised by X-ray crystallography; a schematic diagram of their structures is shown in Figure 1. The fluxional behaviour of the hydrides in (4) was studied using variable temperature 1H NMR spectroscopy (see Figure 2). The result of this study was used in the assignment of hydride positions of (4) in the solid state. 相似文献
56.
Under microwave irradiation and solvent‐free conditions, rare‐earth metal chlorides (RECl3) have been efficient catalysts for one‐pot synthesis of quinoline derivatives to give products in good to excellent yields through the multi‐component reactions of aldehydes, amines, and alkynes. The rare‐earth metal chlorides can be recycled for six times without notable loss of catalytic activities. This new synthetic approach has prominent features of a short reaction time, high yields of products, operational simplicity, broad substrate scopes, environmentally friendly property and commercially available catalysts. It extends the applications of rare‐earth metal compounds as catalysts in organic synthesis. 相似文献
57.
In this study, the first-order shear deformation theory(FSDT) is used to establish a nonlinear dynamic model for a conical shell truncated by a functionally graded graphene platelet-reinforced composite(FG-GPLRC). The vibration analyses of the FG-GPLRC truncated conical shell are presented. Considering the graphene platelets(GPLs) of the FG-GPLRC truncated conical shell with three different distribution patterns, the modified Halpin-Tsai model is used to calculate the effective Young's modulus. Hamilton's principle, the FSDT, and the von-Karman type nonlinear geometric relationships are used to derive a system of partial differential governing equations of the FG-GPLRC truncated conical shell. The Galerkin method is used to obtain the ordinary differential equations of the truncated conical shell. Then, the analytical nonlinear frequencies of the FG-GPLRC truncated conical shell are solved by the harmonic balance method. The effects of the weight fraction and distribution pattern of the GPLs, the ratio of the length to the radius as well as the ratio of the radius to the thickness of the FG-GPLRC truncated conical shell on the nonlinear natural frequency characteristics are discussed. This study culminates in the discovery of the periodic motion and chaotic motion of the FG-GPLRC truncated conical shell. 相似文献
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Yun Wei Shaowu Wang Shuangliu Zhou Lijun Zhang Huimin Qian 《Journal of organometallic chemistry》2008,693(13):2263-2270
Two series of new organolanthanide(II) complexes with tetrahydro-2H-pyranyl- or N-piperidineethyl-functionalized fluorenyl ligands were synthesized via one-electron reductive elimination reaction. Treatments of [(Me3Si)2N]3LnIII(μ-Cl)Li(THF)3 with 2 equiv. of C5H9OCH2C13H9 (1) or C5H10NCH2CH2C13H9 (2), respectively, in toluene at about 80 °C produced, after workup, the corresponding organolanthanide(II) complexes with formula [η5:η1-C5H9OCH2C13H8]2LnII (Ln = Yb (3), Ln = Eu (4)) and [η5:η1-C5H10NCH2CH2C13H8]2LnII (Ln = Yb (5), Ln = Eu (6)) in good yields. All the compounds were fully characterized by spectroscopic methods and elemental analyses. The structures of complexes 3, 4, and 6 were additionally determined by single-crystal X-ray analyses. It represents the first example of solvent-free organolanthanide(II) complexes with fluorenyl ligands. The catalytic properties of the organolanthanide(II) complexes on the polymerization of ε-caprolactone and methyl methacrylate have been studied. The temperatures, solvents and coordination effects on the catalytic activities of the complexes were examined. 相似文献