多工艺金相切割机自动控制系统设计

介绍了以AT89S52单片机为核心的金相切割机控制系统原理和软硬件设计方法.重点介绍了对于不同属性的金属采取的切割速度和切割模式不同,以防止破坏金属的组织和特性.系统通过实际应用检验证明其实用性强,操作方便,运行性能稳定,可靠性强,控制精度满足要求.     

对比研究不同晶粒度高温合金K4169的加工性能

以细晶铸造高温合金K4169为研究对象,对晶粒细化情况和细化晶粒后高温合金加工性能的变化情况分别进行研究,重点通过铣削力测试和加工后表面粗糙度测试实验,分析晶粒大小不同的高温合金试样加工性能变化,以此说明晶粒细化的实际意义.最后分析了加工性能变化的原因,并对铣削力、表面粗糙度与晶粒大小的关系进行了曲线拟合.     

齿轮光整加工工艺及其新进展

提出了齿轮的表面质量对其使用性能和寿命有重要影响的观点，论述了齿轮精加工及光整加工的现状，详细介绍了非传统齿轮光整加工的原理及其表面质量特征，试验结果表明：齿面光整加工后寿命大幅度提高，噪声大幅度降低。     

硬路面干沙层对车辆附着性能的影响

沙尘暴发生时,沙漠公路的硬性路面往往会被沙层覆盖,导致轮胎表面不能与水泥或沥青表面相接触,使轮式车辆的附着系数由橡胶与路面的滑动磨擦系数,变为由轮胎、沙层、路面三者间相互作用形成的附着系数.笔者通过理论分析,得出了车辆在沙漠公路路面上行驶时驱动力与滑转率之间的关系.分析表明:只要存在干沙覆盖层,就存在轮胎相对于路面的滑转率,滑转率的增大进而影响到车辆驱动力的发挥.并提出了解决此问题的方法.     

流体电容仪新的测量模型

本文针对油田生产测井中应用很广泛的流体电容含水率计在理论上和实验上进行了详细的研究。根据现有的实验事实，提出了高含水测量模。该模型认为，对于油水泡状流，即使在水矿化度很高时，流体电容仪仍在０－１００％的含水率范围内有油水分辨能力。     

空间曲面电火花线切割CAD/CAM系统

为解决高速走丝电火花线切割机床加工空间曲面的难题,实现大锥度空间复杂曲面零件的加工,以空间曲面数学模型和数控模型为基础,开发了一种计算机辅助设计/计算机辅助制造(Computer aided design/computer aided manufacturing,CAD/CAM)系统.其硬件系统以研制的数控转摆摆工作台为核心装置,并与现有高速走丝电火花线切割机床结合,组成空间曲面线切割加工系统.其软件系统可以根据上下导线的参数方程进行分析计算,建立空间曲面的三维模型,自动生成NC加工代码,进行加工仿真和空间曲面零件的加工.利用本系统进行典型空间复杂曲面零件的加工试验,结果表明加工结果与仿真结果基本相似.此外,还分析数控模型以及回摆间隙角对加工误差的影响.这些工作为解决高速走丝电火花线切割加工空间曲面的难题打下基础.     

Curve interpolation with variable feedrate for surface requirement

Finish machining of a curved surface is often carried out by an NC system with curve interpolation in the field. This function, called a NURBS interpolation, adopts a feedrate optimizing strategy based on both the geometrical information of the curved path and dynamic properties such as the curvature of the curve, the allowable acceleration and the time constant. However, in the case of a finish cut using a ball-end mill, the curve interpolator needs to take the machining process into account for improved surface roughness, while reducing the polishing time. This surface roughness on high-speed machining is theoretically defined by the feed per tooth and the pickfeed at the given radius of the tool. In this study, the effect of low machinability at the bottom of a tool on surface roughness is also considered. A curve interpolation algorithm is proposed for generating particular feedrate commands that are able to control the roughness of a curved surface. The simulation of the machined surface by the proposed algorithm was carried out, and experimental results are presented. A feedrate scheme that depends on the inclination angle has important potential application in part finishes consistent with prescribed surface roughness. The results show that the proposed algorithm is potentially useful for roughness-controlled machining of curved surface products.     

连轧棒材倍尺飞剪的自动化控制

本文介绍了南昌钢铁厂30万吨棒材生产线倍尺飞剪的工艺特点、技术要求、系统工作原理及控制算法,并简要说明了倍尺飞剪剪切优化的方法。     

Groundwater impact of open cut coal mine and an assessment methodology: A case study in NSW

Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of the many components involved in mine design phase. Groundwater performance also reacts to mining activities from the operational, economic and safety implications perspective. Under NSW planning legislation, as part of the comprehensive risk assessment, a groundwater impact assessment has to be conducted for a coal project to predict and mitigate the impacts in consideration of the government requirements. In this paper, the groundwater assessment modelling of mine pits was discussed in predicting of groundwater inflows and reviewing analytical and numerical approaches. A methodology of groundwater impact assessment for an open cut mine in NSW with a three-dimensional groundwater flow model Modflow Surfact demonstrated its functions in simulating the project's impacts on the groundwater regime. The key findings with mitigations are discussed and recommended in the paper to reduce impacts on groundwater and fulfil regulation requirements in NSW.     

图论在路面裂缝分割中的应用研究

针对图谱划分理论与路面裂缝的特点,提出了一种基于图论的路面裂缝分割方法,该方法将图像作为一个带权图进行分析．建立节点之间的位置距离和灰度差异的能量函数,函数的最小值作为路面裂缝检测的最优分组．通过实验与传统方法最大类间方差法、领域差异直方图法相比,此方法能较好的检测出大于1mm的路面裂缝．