On the view that enterprises cluster is a interactive, inter-influencing ecosystem, and based on summarizing and analyzing the common classifying of enterprises cluster, enterprises clusters were classified into satellitic structure, netlike structure and flatlike structure according to the structure standard.
从企业群是相互作用、相互影响的企业生态系统这一基本观点出发,在对企业群一般分类进行总结分析的基础上,根据结构标准,把企业群分为卫星式结构、网状式结构和平台式结构。
Based on field monitoring and simulation test of strta movement, the hard roof's stepped cantilever structure and its mechanics model are presented.
通过对岩层移动的现场观测和相似模拟,提出了综放采场坚硬顶板的台阶式悬梁结构,建立了相应的数值模型和力学模型,运用有限元法分析了坚硬顶板条件下支承压力对硬煤的压裂效应,依此确定坚硬顶板的最佳预处理步距和液压支架合理工作阻力;并根据力学模型对顶板台阶式悬梁破断瞬态平衡条件及其与液压支架的相互作用关系进行了理论分析,从而形成了硬顶煤、坚硬顶板条件下综放采场围岩控制的基本理论和方法,实现了提高硬顶煤冒放性和回收率的安全、高产高效开采;最后,以一个工程实例佐证了其对坚硬顶板的有效控制 图5,表4,参1
