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本针对省级经贸委的主要职能和特点,提出了省级经贸信息系统建设的总体目标和功能,给出了计算机网络的一般性结构,并对系统的性能和开发策略进行了探讨。 相似文献
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Two novel lanthanide-organic polymers [Er2(pdc)2(o-bdc)(H2O)2]·H2O(1,H2pdc = 2,6-pyridinedicarboxylic acid,o-H2bdc = 1,2-benzenedicarboxylic acid) and Er(Himdc)(mbdc)0.5(H2O)(2,H3imdc = 4,5-imidazoledicarboxylic acid,m-H2bdc = 1,3-benzenedicarboxylic acid) have been synthesized and characterized by elemental analysis,IR,thermogravimetric analysis and X-ray single-crystal diffraction studies.1 crystallizes in monoclinic,space group P21/c,while 2 in the orthorhombic space group Pbcn.Both compounds 1 and 2 display two-dimensional network structures.For 1,the tetranuclear parallelogram {Er4} cluster as a building block is further assembled into a wonderful 2D grid,and the layers are interconnected via hydrogen bonds and π-π stacking interactions to yield a 3D supramolecular architecture;for 2,its configuration is a rare double-decker structure.These two complexes represent good examples for using mix-carboxylate-containing ligands to construct diverse 2D lanthanide coordination polymers. 相似文献
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