基于马德堡半球实验原理的罐车容积超标改造关键技术研究

气体分子对容器壁持续的无规则的碰撞会产生气体压强,导致液体无法充满容器。根据马德堡半球实验原理,对实际充装容积超过出厂资料标注容积的常压罐车进行改造,将金属常压罐体内部防波板上的排气孔下移,在充装液体危险货物时,其内部液面高度即为防波板通气孔高度,可以有效减少常温状态下罐体所能容纳液体危险货物的最大体积,满足相关法律法规要求。     

新型快凝防水涂料在金属屋面上的应用分析

新型快凝防水涂料是一种性能优越、节能环保的快速防水材料,能彻底有效解决传统材料无法根治金属屋漏水问题.本文在简介新型快凝防水涂料主要性能指标基础上,以南宁局集团公司贵港站运用其为例,印证此涂料通过改进工艺应用到电气化铁路的站台雨棚、旅客天桥等营业线建构筑物金属屋面补漏后效果非常显著,改进后的补漏工艺较传统补漏工艺在天窗...     

金属波纹管涵力学性能数值模拟

基于青藏铁路波纹管涵试验工程,建立金属波纹管涵的等效受力模型,运用有限元方法对其进行数值模拟,研究铁路路基荷载及列车活载共同作用下金属波纹管涵的应力、应变及变形特点.研究发现,波纹管涵不论是竖向、轴向还是环向的拉压应变均是通过波纹沿环向在波峰与波谷之间相互传递,另外拉压应变在竖向、轴向和环向也是交替出现,相互转换.结果表明,波纹管涵身的波纹具有明显的传递应变的性能.波纹管涵的这一特点不但能有效抵抗由于竖向荷载造成的侧向变形,还能有效地把竖向荷载造成的竖向变形及侧向变形通过波纹传递到轴向,充分表现了它适应变形的优良性能.     

浅谈喷涂基本工艺

汽车喷涂的主要作用有二:一是装饰:二是保护。汽车外表经过喷涂．使漆膜光亮美观．色彩照人．给人以美的感受。喷涂对金属物体表面涂装一层薄膜,可阻隔空气、水分、阳光及腐蚀介质的侵蚀．以保护金属的使用寿命。为了达到喷涂汽车的基本目的．在喷涂过程中应按一定的工艺规程进行喷涂,才能起到喷涂的作用。下面就把笔者在喷涂汽车时总结的一般工艺规程介绍给同行．仅供参     

CAE-Based Robust Optimization for Deep-Drawing Process of Sheet Metal Forming Using Grey Relational Analysis Method

The theory of grey systems is a new technique for performing prediction, relational analysis and decision making in many areas. The grey relational analysis was used to optimize the deep-drawing process parameters with considerations of the multiple response (the wrinkle, crack and thinning variation). The deep-drawing parameters, such as the blank holding force (F_ bh ), the radii of punch and die (R_1,R_2), the coefficients of friction (μ_1,μ_2,μ_3) are considered. An orthogonal array is used for the experimental design. The multiple response values are obtained making use of finite element analysis (FEA). Optimal process parameters are determined by the grey relational grade obtained from the grey relational analysis for multi-performance characteristics (the wrinkle, crack and the thinning). The analysis of variance (ANOVA) for the grey relational grade is implemented. The results show that the quality of stamped parts can be improved effectively through the new approach. The grey relational analysis can be applied in sheet metal forming.     

A Theoretical Model on Solvus Line Prediction of Film and Its Application in Nanogranular Al-Cu System

A theoretical model on the solvus line prediction of a film was proposed and applied to a nanogranular Al-Cu system. The calculation results show that the solvus line of solute Cu will markedly lower with the decrease of grain size, namely, the starting temperature of θ(Al_2Cu) precipitation in a nanogranular Al-Cu film will markedly lower than that of conventional coarse grain alloy with the same Cu concentration, and the precipitation temperatures calculated are comparable with the experimental ones. The theoretical model can be simply used to calculate the starting temperature of precipitation in Al-Cu films under three states: ① films with substrate; ② films without substrate; ③ ultrafine grain bulk alloy. As a result, the model is universal, moreover, can be, in principle, used to predict precipitation temperature in other systems.     

CoSe2@石墨烯复合气凝胶的制备及其锂离子电池性能研究

以普鲁士蓝类似物为前驱体、石墨烯气凝胶(GA)为载体,通过自组装、冷冻干燥和高温硒化等方法构筑了CoSe₂@GA复合材料,并将其用作锂离子电池的负极材料.研究表明,CoSe₂@GA具有稳定的宏观体结构,其中CoSe₂纳米立方体均匀地分散于GA的三维网络中.CoSe₂@GA电极在0.1 A·g^-1时循环90圈后的比容量为1 405 mAh·g^-1,当电流密度增大到1 A·g^-1、循环500圈仍具有600 mAh·g^-1的高比容量.CoSe₂和GA两组元之间的协同作用使得CoSe₂@GA电极展现出较好的储锂性能,GA的加入不仅提高了电极的导电性,而且缓解了活性颗粒在充放电过程中的团聚和体积膨胀.     

鉴别态阳膜真假有诀窍

太阳膜分色膜和防爆膜2种.色膜是指有色彩涂层阻隔紫外线的透明薄膜;防爆膜是指有色彩涂层并经过防爆特殊处理阻隔紫外线的透明薄膜. 颜色:防爆膜采用金属溅射工艺,将镍、银、钛等高级金属涂于高张力的天然胶膜上,无论在贴膜过程中还是日后的使用过程中,都不会出现掉色、退色现象.普通色膜将颜色直接溶在胶膜中,撕掉上层塑料纸后,用力刮黏贴面,会有颜色脱落现象,这种膜一二年就需要更换.     

金属波纹管试验研究

应用微机控制液压伺服动静试验机和稳压压力系统等进行金属波纹管压力及位移条件下的疲劳寿命试验,并通过试验结果与软件分析结果的对比,不断改进和提高软件分析的准确度.另外,通过对3种不同材料的真实应力-应变的试验,为软件分析用的材料数据库提供了真实的材料性能参数,为金属波纹管的设计、研究提供了数据和试验验证.