Dam made of Portland cement or cyclopean concrete (i.e. with large stones). A dense material is important in its construction to reduce percolation and ensure permanence; a relatively dry mix with careful tamping is required.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。