英语翻译Elemental analyses of the samples are summa-rized in Tab

英语翻译
Elemental analyses of the samples are summa-rized in Table 1.The most striking feature of the results is that the content of aluminum ions decreased progressively while that of silicon ions increased as crystallization proceeded.The increase in silicon content can be explained by a loss of colloidal silica particles at the washing stage of the samples; however,the decrease in aluminum samples; however,the decrease in aluminum content is rather puzzling and may be explained by the presence of excess aluminum ions as boehm-ite gel particles while some part of the phosphate ions are present in solution.
From the results mentioned above we suggest the following scheme for the crystallization of Ni-SAPO-34 by the rapid crystallization method.
(1) At the early stage of the crystallization,an aluminophosphate-like framework is formed.Most of the silicon ions are present as colloidal silica particles.At this stage,Ni2+ ions are present as octahedral coordination and presumably are occluded in the defects of SAPO-34.
(2) Crystallization proceeds with increasing temperature and silicon ions begin to be incorporated into the framework.Ni2+ ions fall into the tetrahedral sites,forming Ni-SAPO-34 at the final stage of the crystallization.