一种高效强K—栅栏覆盖构建算法

K－栅栏覆盖是无线传感器网络覆盖控制的研究热点之一。本文构建了强栅栏覆盖模型,提出了分区强K－栅栏覆盖构建算法PMNSB,用最少的节点形成强栅栏。首先把监控区域分成多个子区域,通过匈牙利算法选用移动距离之和最少的网格集合为基准1－栅栏覆盖,缺少移动节点的子区域,选择附近区域的剩余移动节点修补形成1－栅栏覆盖。水平相邻的两个子区域之间构建竖直栅栏,这些1－栅栏合起来构成强K－栅栏覆盖。仿真结果证明了该方法的有效性,本文的研究对提升无线传感器网络的性能具有重要的理论与实际意义。     

Optimal cyclic single crane scheduling for two parallel train oilcan repairing lines

Crane is widely used to move a heavy object from one place to another not only in manufacturing industry but also service industry. As an important resource in the train oilcan repairing, crane scheduling affects directly the productivity of the systems. In this paper, we study cyclic single crane scheduling problem with two parallel train oilcan repairing lines, where jobs are loaded into the line at one end and unloaded at the other end. The processing time at each workstation must be within a given range. There is no buffer between these stations. A crane is used to move jobs between the workstations in two parallel lines. The objective is to schedule the moves to minimize the production cycle. We proposed a time way diagram for two parallel lines and developed a mixed integer linear programming model. Then we extended the model to the scheduling problem with multi-station to eliminate the bottleneck in lines. Examples are given to demonstrate the effectiveness of the model.     

尺寸链在机器装配中的应用

着重分析应用尺寸链的原理，达到装配精度的方法，合理解决机器质量的保证问题。     

激光成形修复Inconel 625合金的工艺特性和组织研究

对激光成形修复Inconel 625合金的工艺特性以及不同区域的组织进行了研究。结果表明:激光成形修复Inconed625合金的工艺范围较宽;激光功率主要影响单道修复层的宽度;扫描速度对单道修复层的尺寸影响较为显著,而送粉率的影响较小。基材的相组成包括γ(Ni-Cr)基体相、大尺寸(约10μm)块状MC型碳化物(M为Nb和Ti)、沿晶界析出的小尺寸(约0.5μm)块状MC型碳化物以及不规则形状的Laves相。修复区组织为呈外延生长的柱状枝晶,相组成为γ基体相、沿枝晶界析出的Laves相以及少量MC型碳化物。层与层界面处Laves相析出急剧增加形成层间过渡区。     

松散破碎围岩锚注在返修巷道中的研究应用

通过对锚注支护机理的阐述,研究锚注支护修复巷道的可行性。结合丁集矿典型返修巷道变形与破坏形式特征,设计该返修巷道锚注支护方案,并完成了现场监测分析与评价。实践表明,该技术是解决深井高应力软岩返修巷道支护的有效途径,具有较高的推广应用价值。     

锚注加固技术在高应力碎胀岩体巷道支护中的应用研究

 锚注加固技术能明显地改善巷道围岩受力状态、增强巷道整体承载能力、有效地控制巷道变形破坏,提高巷道支护的稳定性和安全性。针对魏家地煤矿二号石门运输大巷经多次返修,巷道变形依然严重的问题,运用锚注加固理论与技术,研究了高应力状态下的碎胀岩体锚注加固支护参数并进行了实施,结果表明,支护效果显著,取得了良好的技术和经济效益。     

基于变分隐式曲面的三角网格孔洞修补

针对三角网格模型存在的孔洞问题提出一种基于变分隐式曲面的孔洞修补算法。首先,利用孔洞边界信息构造插值孔洞边界的变分隐式曲面并将其网格化,得到初始孔洞网格,再利用边界点裁剪初始孔洞网格,最后把裁剪后的孔洞网格与初始网格拓扑合并,完成孔洞修补。算法充分考虑了孔洞周围的信息,使得孔洞网格与原始网格光滑连接,取得了比较好的效果。     

触变型堵剂GX—I封堵大孔道技术的研究及应用

用一种工业无机胶结材料、固化剂（混合无机盐溶液）及触变性调节剂（复合无机物）配制成了具有明显触变性的堵剂浆液GX－I。详细考察了各个组份的用量对浆液初凝时间、触变性（以浆液静切力G10s和G10min表示）、流变性及固结体抗压强度的影响。得到了分别适用于封堵低温井大孔道、裂缝及封堵水泥环以上套漏（无机材料用量以水灰比表示W／C＝0.44-0.5),封堵较高井温油井出水层（W／C＝0．67－1．0）,水井调剖（W／C＝1．2－1．4）的GX－I堵剂。给出了可用于60－90℃、初凝时间为6－10小时的3个基本配方。用这3个配方堵剂浆液堵岩心,堵塞率＞97％。简要介绍了中原油田11口井使用GX－I堵剂的良好效果,包括层间封窜2口,堵套漏1口,油井堵水3口,注水井分层调剖5口,详细分析了封堵1口注水井管外窜槽情况。     

转炉喷补技术及其发展

综合分析了转炉喷补技术及其发展。研究分析了湿法、干法、半干法及火焰喷补方法的使用特点。指出了转炉喷补技术的发展方向。     

Case Study: Dillon Dam Trashrack Damage

In 1986 the trashracks on the intake to the outlet works at Dillon Dam in Colorado were damaged due to filling the intake tunnel too rapidly. As the air from the tunnel was discharged through the intake structure, high velocities displaced two horizontal trashracks and removed one vertical trashrack from its guides. This damage was discovered through an underwater inspection in 1996. The addition of an air vent and the establishment of a filling procedure provided a solution to the problem. The quantity of air in the intake tunnel was reduced through the installation of a 102 mm (4 in.) diam air valve and 63.5 mm (2??in.) vent hole in the crown of the intake tunnel at the control tower. Since the vent could not remove all the air in the tunnel, the tunnel was filled by opening the emergency gate 7.9 mm ( in.) and letting the conduit fill over a 12 h period.