<正>针对复杂生态信息、的存储与管理问题，提出一种基于B+树的多维层次聚集立方体存储结构模型。通过将d维数据空间构建成多维层次式B+树，并节点进行压缩的二进制维层次编码，在此基础上实现了模型的快速查询、数据更新与模式更新算法。与传统的DataCube相比，MHCube具有较好的查询与更新功能。生态数值实验表明。镬型可为复杂生态信息的存储与管理提供较好的解决方案。

The mechanical properties of porous cement concrete were studied in the paper. The effects of water-ash ratio, porosity, grading, silica fume, and cinnatnene-acrylate on compressive and flexural strength of the mixture were investigated as well. The results showed that the compressive and flexural strength of the mixture increased into one extenl firstly,then decreased with water-ash ratio increasing. The strength of the mixture decreased obviously with porosity increasing. Changing grading and adding strengthing agent (silica fume and cinnamene-acrylate) took effects on the strength of the mixture. The study was helpful to the composition design of porous cement concrete.