考虑中间主应力的非均匀应力场圆形巷道围岩塑性区分析

基于Drucker-Prager准则,引入中间主应力系数,推导出不同侧压系数下巷道围岩塑性区边界线方程,用于预测不同侧压系数下巷道围岩塑性区的大小和形状。用单因素分析法,考虑不同中间主应力下,巷道围岩塑性区半径的变化规律。在侧压系数λ=1的时候,对在D-P准则下和在Mohr-Coulomb准则下巷道围岩塑性区的大小进行比较。侧压系数越偏离于1,巷道围岩塑性区水平方向和垂直应力侧差异增加,对围岩塑性区的大小和形状影响也越大;随中间主应力增大,塑性区范围越小。     

复杂线路条件下盾构下穿民房掘进参数优化研究

以天津地铁三号线水上北路站~吴家窑站盾构区间左线线路为研究背景,以盾构施工控制技术为研究方向,通过试验段掘进、现场数据监测分析、计算模拟分析、盾构施工参数选取、实际监测数据分析等,研究了在复杂线路条件下(变坡度,小曲线半径等),盾构机掘进的参数优化。以试验段的跟踪监测调整数据为分析依据,着力主要控制参数,对掘进参数的选取采用理论计算结合实际监测的方法,论证参数的可适用性。研究结果表明:采用合理的掘进参数,能有效控制盾构机在复杂线路条件下下穿建筑物时的沉降。     

考虑卸压和抽采效果的水力冲孔布孔参数优化研究

为了提高水力冲孔技术的消突效果,建立了考虑煤的塑性软化、扩容特性和流变特性的钻孔周围煤体黏弹塑性模型,得到了不同冲煤量钻孔的卸压范围,建立了考虑渗透率动态变化和吸附特征的渗流-应力耦合模型,采用COMSOL软件对建立的耦合模型进行求解,研究了不同冲煤量钻孔的抽放半径,优化了水力冲孔布孔参数。结果表明:在确定水力冲孔布孔参数时,应综合分析水力冲孔的卸压范围和抽放半径,冲煤量为0.5,1.0和1.5 t/m时,卸压范围分别为3.71,4.61和5.8 m,抽放半径分别为3.5,4.3和5.0 m,义安矿平均冲煤量为1.0 t/m,由此确定水力冲孔布孔间距为8.0 m,区域措施效果检验和工作面预测数据表明,确定的布孔参数合理可靠。     

激光共焦透镜曲率半径测量系统

基于共焦技术独特的轴向层析定焦能力并结合气浮导轨平移台和激光干涉仪测长系统,研制了一套高精度、非接触激光共焦透镜曲率半径测量系统。该系统利用共焦轴向光强响应曲线的峰值点对应系统物镜聚焦焦点这一特性,使用峰值点对被测透镜的猫眼位置及共焦位置进行精确定位,并结合激光干涉仪获得透镜猫眼位置及共焦位置坐标值,从而计算得到透镜的曲率半径。系统由主控软件控制气浮导轨带动被测透镜在猫眼位置及共焦位置附近进行扫描测量,并实现信号采集和数据处理。实验表明,利用该系统测量透镜的曲率半径时,测量重复性优于2 μm,满足国内高精度透镜曲率半径测量的精度需求。该系统测量速度快、操作简便、结构简单且易于实现小型化。     

PVC塑胶地板在医院的应用

介绍了一种新型医院地面装饰材料在医院的应用,并对塑胶地板安全性、环保性、稳定性、消音性、热传导性、耐磨性、耐久性、防水、防尘、防渗、防菌、防霉、防蛀等性能在医院环境中所发挥的作用进行了介绍。其应用的同时要注意施工方法和清洁保养。     

Wood‐Plastic‐Composites: Rheologische Charakterisierung und Füllverhalten im Spritzgießprozess

Wood‐plastic composites (WPC) show a complex and completely different material and flow behavior in comparison to pure polymers. Especially the flow behavior is very important for the processing of these composites. In the following article results of rheological characterization and investigations of the filling behavior during the injection molding process are presented. Furthermore, appearing challenges and possible methods of resolution are discussed.     

Experimental Investigation of Electrostatic Separators of Plastic Particles using Different Charging Devices

Tribo-electrostatic separation is a clean technology that enables the recycling of plastics contained in granular waste of electric and electronic equipment (WEEE). The granules are first charged using a tribocharging device and then separated in a horizontal intense electric field generated between two vertical electrodes energized with two high-voltage supplies of opposite polarities. The aim of this paper is to perform a comparison between three different tribocharging devices commonly used: the fluidized bed, the static charger, and the tribo-cyclone. The study was carried out using the same granular sample comprising 50% PVC (Polyvinyl chloride) and 50% HDPE (High-density polyethylene) particles of 1–2 mm average granulometric size. In spite that particles acquire higher electric charge using the cyclone device, separation efficiency is better with the fluidized bed device.     

Progress in Thermal Contact Resistance

The developments of aeronautics and astronautics require engines of higher quality. The temperature distribution in combustion engine is highly influenced by the thermal conduct resistance. To predict the temperature field of the hot-end assemblies of combustion engine, the thermal contact resistance must be considered. The object of the study is to propose a model of high application including in conditions of high temperature and high pressure. Up to date, many models and empirical or semi-empirical corre...     

1500mm彩色涂层贴塑钢板生产线及关键技术

绍了西安重型机械研究所开发的国内首条彩涂贴塑板生产线的主要技术参数、设备性能、关键技术,设备生产情况良好,产品在国内外市场均具有竞争力。     

高速滚子链的多冲磨损特性

汽车链条的高速多冲特性不同于其它高速滚子链，高速下的多冲特性以及速度与载体交变特性的双重效应，对其耐磨性能提出了荷刻的要坟，而速度与载荷交变特性的影响尤为重要。销轴、套筒零件表层的抗多冲过载能力和抗多冲磨损能力以及心部的抗塑变能力和表层的循环软化与硬化特性是汽车用高速滚子链磨擦学设计的关键因素。