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Russian Chemical Bulletin -  相似文献   

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On the territory of the former USSR.  相似文献   

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LaNi5类合金的软化学合成   总被引:3,自引:0,他引:3  
LaNi5类合金是公认的性能优良的常温储氢材料.和其它的稀土过渡金属金属间化合物不同,由于存在不同的扩散机理,用还原-扩散方法很难制备物相纯的LaNi5合金.反应时间、反应温度和所用镍粉的粒径大小都决定着最后LaNi5合金的纯度.......  相似文献   

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This review provides a survey of the advances in the methods of formation and chemical reactivity of bicyclic [1,3,4]thiadiazole 5-5 systems containing ring-junction nitrogen over the period from 1989 to the beginning of 2017.  相似文献   

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孙锡泉 《大学化学》2005,20(2):23-26
探讨了华东理工大学等编《分析化学》(第5版)中波谱分析法、紫外吸收光谱法、气相色谱法、基本单元章节中内容取舍的问题;并对教材中的几个其他问题进行了探讨。  相似文献   

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A Periodic System was proposed for the elements 1–172 by Pyykkö on the basis of atomic and ionic calculations. In it, the elements 121–138 were nominally assigned to a 5g row. We now perform molecular, relativistic four‐component DFT calculations and find that the hexafluorides of the elements 125–129 indeed enjoy occupied 5g states.  相似文献   

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Four-membered and six-membered rings were chosen as substructure units to simulate molecular sieve of APO-5 type. The stability of various orderings of AlO4 and PO4 tetrahedra in micros tracture of the APO-5 type was studied by using CNDO/2 method.By means of analysing energies of systems, frontier orbitals, charges and bond orders in detail, Loewenstein's empirical rule is explained theoretically.  相似文献   

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利用丙酮和草酸二乙酯为原料,通过Claisen酯缩合、肟化环合与氨水氨解,合成磺胺甲基异噁唑的关键中间体——5-甲基-3-异噁唑甲酰胺。通过红外光谱、核磁共振、熔点测定等方法验证其结构。本实验综合运用有机合成、产物分离和结构鉴定中的多种操作单元,并训练红外光谱、核磁共振等常用仪器分析技术,适合学生进行综合有机化学实验。  相似文献   

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