Co is in present tetrahedral environments .
通过表面活性剂的模板作用合成出含钴和硅的中孔磷铝分子筛 ,2 7Al和3 1PMASNMR谱的结果表明 ,Si和Co分别进入分子筛骨架 ;UV DRS谱的结果表明在分子筛骨架上Co(Ⅱ )以四面体配位形式存在 ,少量Si的加入有利于Co进入骨架位 。
This paper suggests generalized tetrahedron polar coordinate and a smoothness condition and it is its specific application to change “singular” boundary element method to “non-singular” boundary element method so as to reach higher accuracy and efficiency.
提出了广义四面体极坐标和一个光滑条件 ,利用常规高斯求积实现对n(≥ 2 )维欧氏空间中各阶强、弱奇异积分的数值估值。