Based on five basic assumptions, of the ground subsidence and collapse was using theoretical analysis method, the nature revealed from the mechanics point. Divided into four phases as groundwater level descent, soil c...Based on five basic assumptions, of the ground subsidence and collapse was using theoretical analysis method, the nature revealed from the mechanics point. Divided into four phases as groundwater level descent, soil cavity formation, soil cavity expansion, and ground collapse emersion, the whole process of ground subsidence and collapse was analyzed in detail. The study shows that ground subsidence and collapse is the macro- scopic performance and inevitable result of the soil cavity expansion and development, and the dynamic mechanics is the spalling force induced by the groundwater falling. The activities of underground water play a very important role in the process from the formation of soil cavity to the production of ground subsidence.展开更多
The application of the finite layer & triangular prism element method to the 3D ground subsidence and stress analysis caused by mining is presented. The layer elements and the triangular prism elements have been a...The application of the finite layer & triangular prism element method to the 3D ground subsidence and stress analysis caused by mining is presented. The layer elements and the triangular prism elements have been alternatively used in the numerical simulation system, the displacement pattern, strain matrix, elastic matrix, stiffness matrix, load matrix and the stress matrix of the layer element and triangular prism element have been presented. By means of the Fortran90 programming language, a numerical simulation system based on finite layer & triangular prism element have been built up, and this system is suitable for subsidence prediction and stress analysis of all mining condition and mining methods. Comparing with the infinite element method, this approach dramatically reduces the size of the set of equations that need to be solved, and greatly reduces the amount of data preparation required. It not only saves the internal storage, and the computation time, but also decreases the cost.展开更多
本文旨在分析肺磨玻璃结节(GGN)研究的现状、热点及存在的问题.以Web of Science核心合集数据库为数据来源,纳入2003年1月至2019年12月肺GGN相关文献2557篇,利用CiteSpace依次分析合作网络、共被引网络和关键词共现.发现该领域有核心作...本文旨在分析肺磨玻璃结节(GGN)研究的现状、热点及存在的问题.以Web of Science核心合集数据库为数据来源,纳入2003年1月至2019年12月肺GGN相关文献2557篇,利用CiteSpace依次分析合作网络、共被引网络和关键词共现.发现该领域有核心作者、机构、文献存在;已形成稳定的研究团队,但跨团队的合作依然不足;美国、日本和中国为该研究领域的排头兵,日本奠定基础,美国处于核心,中国是成长新秀;CT设备的更新和计算机技术的升级导致研究热点的大幅度转移,对肺GGN良恶性鉴别和新型手术方式的探究是当前热点,目前研究重点是利用CT鉴别,进行预后管理和随访,提高存活率.肺GGN领域的研究较稳定、成熟、有规模,需增强不同研究团队的合作.此领域受技术更新影响较大,后继应更关注新技术的使用.展开更多
基金Supported by the National Natural Science Foundation of China(10702072)the Technology Innovation Fundation of China Coal Research Institute(2009CX01)
文摘Based on five basic assumptions, of the ground subsidence and collapse was using theoretical analysis method, the nature revealed from the mechanics point. Divided into four phases as groundwater level descent, soil cavity formation, soil cavity expansion, and ground collapse emersion, the whole process of ground subsidence and collapse was analyzed in detail. The study shows that ground subsidence and collapse is the macro- scopic performance and inevitable result of the soil cavity expansion and development, and the dynamic mechanics is the spalling force induced by the groundwater falling. The activities of underground water play a very important role in the process from the formation of soil cavity to the production of ground subsidence.
文摘The application of the finite layer & triangular prism element method to the 3D ground subsidence and stress analysis caused by mining is presented. The layer elements and the triangular prism elements have been alternatively used in the numerical simulation system, the displacement pattern, strain matrix, elastic matrix, stiffness matrix, load matrix and the stress matrix of the layer element and triangular prism element have been presented. By means of the Fortran90 programming language, a numerical simulation system based on finite layer & triangular prism element have been built up, and this system is suitable for subsidence prediction and stress analysis of all mining condition and mining methods. Comparing with the infinite element method, this approach dramatically reduces the size of the set of equations that need to be solved, and greatly reduces the amount of data preparation required. It not only saves the internal storage, and the computation time, but also decreases the cost.
文摘本文旨在分析肺磨玻璃结节(GGN)研究的现状、热点及存在的问题.以Web of Science核心合集数据库为数据来源,纳入2003年1月至2019年12月肺GGN相关文献2557篇,利用CiteSpace依次分析合作网络、共被引网络和关键词共现.发现该领域有核心作者、机构、文献存在;已形成稳定的研究团队,但跨团队的合作依然不足;美国、日本和中国为该研究领域的排头兵,日本奠定基础,美国处于核心,中国是成长新秀;CT设备的更新和计算机技术的升级导致研究热点的大幅度转移,对肺GGN良恶性鉴别和新型手术方式的探究是当前热点,目前研究重点是利用CT鉴别,进行预后管理和随访,提高存活率.肺GGN领域的研究较稳定、成熟、有规模,需增强不同研究团队的合作.此领域受技术更新影响较大,后继应更关注新技术的使用.
