OLE DB是被许多第三方数据挖掘产品供应商所支持的微软制定的工业标准。OLE DB for DataMining以表的形式表达数据挖掘模型对象,而且也提供一种类似SQL的DDL使开发者能更好地建立数据挖掘应用。给出了一个关于运用SQL Server 2000构建...OLE DB是被许多第三方数据挖掘产品供应商所支持的微软制定的工业标准。OLE DB for DataMining以表的形式表达数据挖掘模型对象,而且也提供一种类似SQL的DDL使开发者能更好地建立数据挖掘应用。给出了一个关于运用SQL Server 2000构建数据挖掘应用的实例。展开更多
A device for supporting soft rock masses combined with a constant resistance structure characterized by constant resistance and large deformation at the end of a steel bar, known as the constant resistance and large d...A device for supporting soft rock masses combined with a constant resistance structure characterized by constant resistance and large deformation at the end of a steel bar, known as the constant resistance and large deformation（CRLD） bolt, has recently been developed to counteract soft rock swelling that often occurs during deep mining. In order to further study the mechanical properties of the CRLD bolt, we investigated its mechanical properties by comparison with the conventional strength bolt（rebar） using static pull tests on many aspects, including supporting capacity, elongation, radial deformation, and energy absorption. The tests verified that the mechanical defects of the rebar, which include the decrease of bolt diameter, reduction of supporting capacity, and emergence and evolution of fracture until failure during the whole pull process, were caused by the Poisson＇s ratio effect. Due to the special structure set on the CRLD bolt, the bolt presents a seemingly unusual phenomenon of the negative Poisson＇s ratio effect, i.e., the diameter of the constant resistance structure increases while under-pulling. It is the very effect that ensures the extraordinary mechanical properties, including high resistance, large elongation, and strong energy absorption. According to the comparison and analysis of numerical simulation and field test, we can conclude that the CRLD bolt works better than the rebar bolt.展开更多
文摘采用多体动力学建模仿真程序Recur Dyn/Track构建海底履带式集矿机多体动力学模型,实现了海底底质特殊力学模型在集矿机多体动力学模型中的二次开发与集成。开展小型履带式试验样车行走性能测试,与相应二次开发多体动力学模型仿真结果相比较,进一步验证二次开发建模方法的计算准确性。基于多体离散元法,应用Recur Dyn Process Net平台进行二次开发,采用C#语言编写建立超长采矿管线多体离散元动力学模型的自动参数化建模计算程序。集成海底履带式集矿机多体动力学模型与采矿管线系统多体离散元动力学模型,实现了深海采矿整体系统的多体动力学模型集成构建与联动仿真,获得并分析联动过程各子系统空间运动状态变化、子系统间相互作用力变化等动力学特性,为实际深海采矿系统的整体集成设计、性能预测及作业操控提供了参考。
基金supported by National Key Research and Development Program(2016YFC0600901)the National Natural Science Foundation of China(Grant Nos.51374214,51134005 and 51574248)+1 种基金the Special Fund of Basic Research and Operating of China University of Mining&Technology,Beijing(Grant Nos.2009QL03)the State Scholarship Fund of China
文摘A device for supporting soft rock masses combined with a constant resistance structure characterized by constant resistance and large deformation at the end of a steel bar, known as the constant resistance and large deformation（CRLD） bolt, has recently been developed to counteract soft rock swelling that often occurs during deep mining. In order to further study the mechanical properties of the CRLD bolt, we investigated its mechanical properties by comparison with the conventional strength bolt（rebar） using static pull tests on many aspects, including supporting capacity, elongation, radial deformation, and energy absorption. The tests verified that the mechanical defects of the rebar, which include the decrease of bolt diameter, reduction of supporting capacity, and emergence and evolution of fracture until failure during the whole pull process, were caused by the Poisson＇s ratio effect. Due to the special structure set on the CRLD bolt, the bolt presents a seemingly unusual phenomenon of the negative Poisson＇s ratio effect, i.e., the diameter of the constant resistance structure increases while under-pulling. It is the very effect that ensures the extraordinary mechanical properties, including high resistance, large elongation, and strong energy absorption. According to the comparison and analysis of numerical simulation and field test, we can conclude that the CRLD bolt works better than the rebar bolt.
