Gypsum was used as raw material to prepare porous hydroxyapatite with hierachical structure by hydrothermal reaction.
使用石膏作为原料,通过水热反应得到具有特殊结构的多孔羟基磷灰石.
Based on the Hierachical Cluster Analysis, this paper studies the proportion of minimum living standard guarantee system financed by government grant.
使用聚类分析方法研究了中央财政对城市居民最低生活保障制度资助比例的问题。
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