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991.
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The crystal structure of quasi-one-dimensional compound Ni[S2CPyrd]2 (Pyrd=pyrrolidine) has been determined by X-ray diffraction technique. It crystallizes in the monoclinic system, space group P21/c, with lattice parameters a=0.631 6(1) nm, b=0.746 5(2) nm, c=1.576 5(4) nm, β=106.08(3)°, and Z=2. The nickel atom had a square-planar geometry. The most prominent feature in the crystal structure is that the bis(pyrrolidinedithiocarbamato) nickel(Ⅱ) forms a well-separated stacking column along the a-axis through supramolecular interaction, and they are uniformly spaced to give a helical one-dimensional chain structure. CCDC: 220648. 相似文献
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含联萘基团的旋光性聚喹啉的合成与性质 总被引:7,自引:0,他引:7
由2,2′-二甲氧基-1,1′-联萘 了旋光活性的2,2′-二甲氧基-6,6′-二乙酰基-1,1′-联萘(DMDABN),经元素分析,NRM,IR和MS等方法对其进行结构表征,DMDABN与3,3′-二苯甲酰基-4,4′二氨基-二苯基醚通过Friedlander反应合成了旋光性聚喹啉,所制备的聚喹啉具有较高的玻璃化转变温度(474-578K),热分解温度(703-770K),很好的耐溶性能和较强的旋光活性。 相似文献
997.
Highly dispersed Ni catalysts on spherical SiO2 were prepared by simple impregnation of Ni(acac)2, [Ni-(NH3)6-n(H2O)n]^2+, [Ni(en)3]^2+ and [Ni(EDTA)]^2-. Pulse adsorption of H2 and TEM analysis results confirmed that Ni was dispersed very well on the surface of SiO2 even after calcination (4 h) and reduction (1 h) at high temperature of 800 ℃. These highly dispersed and uniquely sized Ni crystallites were more stable and more reactive for both autothermal reforming and partial oxidation of methane in fluidized reactor. 相似文献
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LV Peng ZHANG ZaiQiang GUAN JinTong WANG XiaoDong HOU XiuLi ZHANG LingYan WANG JiJun CHEN Bo GUAN QingFeng 《中国科学:物理学 力学 天文学(英文版)》2013,(9):1689-1693
Mo/Si multilayers were fabricated by using magnetron sputtering method at different background pressures:6×10-5 Torr,3×10-5 Torr,and 3×10-6 Torr.The reflectivity of the Mo/Si multilayers increased from 1.93% to 16.63%,and the center wavelength revealed a blue shift to 0.12 nm with the decrease of background pressure.Grazing incident X-ray diffraction(GIXRD) indicated that multilayers fabricated at high background pressure possessed better periodic structure and thinner Mo-on-Si interlayers.Low crystallization degree in(110) preferred the orientation of Mo layers and serious interdiffusion in the Mo/Si multilayers fabricated at low background pressure were observed by transmission electron microscopy(TEM).According to quantitative analysis of microstructural parameters,the Mo layers thickness and thickness ratio of Mo/Si multilayers both decreased and approached the design value gradually by the decrease of background pressure.In addition,the thicknesses of Mo-on-Si and Si-on-Mo interlayers were 1.17 nm and 0.85 nm respectively.It is suggested that the influence of background pressures on the microstructure has a critical role in determining the optical properties of Mo/Si multilayers. 相似文献
999.
In a unified algebraic scheme,we investigate the relation between the E(5) symmetry and the interacting boson model beyond the mean-field level.The results indicate that the E(5) symmetry is actually in between the critical point of the U(5)-O(6) transition and the O(6) limit but it is fairly close to the former based on the phase diagram of the interacting boson model at the large boson number limit.In addition,an algebraic Hamiltonian of the E(5)-β2n model is proposed. 相似文献
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