时序效应对离心压缩机叶片非定常气动负荷影响

针对国内某大型企业不同机组离心压缩机叶轮叶片进行非定常流动数值分析,通过求解三维瞬态N-S方程组,得到流场分布和叶片表面的静压载荷信息。利用数值实验方法获得离心压缩机不同时序位置叶轮叶片表面动载荷的变化,并通过傅里叶变换得到叶轮叶片表面动载荷的分布特性,进而分析不同时序位置叶轮叶片表面气动负荷的差异。数值计算表明,时序效应对离心压缩机流道内流动以及叶轮叶片的非定常气动负荷存在不可忽略的影响,且合适的时序位置具有改进压缩机级性能的潜能。动载荷是压缩机叶轮叶片结构发生疲劳破坏的诱因,且不同机组离心压缩机中的时序效应对气动载荷的影响具有一致性。     

Microstructure of reactive sintered Al bonded Si3N4-SiC ceramics

Aluminium nitride-silicon nitride-silicon carbide （AIN-Si3N4-SiC） composite ceramics were prepared to increase the bending strength and improve the phase structure of Si3N4-based ceramics. The ceramics were made by reactive sintering in N2 atmosphere at 1 360 ℃, using Al as sintering additive. The phase composing of ceramics was identified with an X-ray diffractometer and the microstructure of the materials was studied by scanning electron microscopy. The results indicate that the phase structure is affected remarkably and the interface modality is changed. The interface between Si3N4 and SiC becomes blurry and that between SiC and AlN matches more better at the same time. But the liquid-phase appears during the reactive sintering along with the addition of AI by which the melting point of Si is decreased. The appearance of liquid Si decreases the bending strength of the ceramics. Lower temperature nitrification technic was introduced to avoid the appearance of liquid-phase Si. The optimum addition of Al was investigated by XRD and SEM analysis in order to obtain the maximal bending strength of materials.     

3D finite element method analysis of deformation and temperature rise during equal-channel angular pressing

The material flow, temperature rise of the billet and pressing load during equal-channel angular process （ECAP） were studied by using 3D finite element method for Cu at different comer angle of mold, interfacial friction coefficient between the billet and the mold. As comer angle increases, the magnitude of shear deformation decreases and the strain difference between upper and lower part of the material becomes more apparent. The pressing load and peak temperature rise of the billet become low as the interracial friction coefficient decreases. The effects of the comer angle of mold on the temperature rise of the billet can be ignored, but the effects of the friction coefficient between the mold and the billet must be taken into account. For pressing load, the effect of the friction coefficient is larger than that of the comer angle. A good agreement between the simulated and measured material flow is obtained.     

甲醛阻聚剂作用原理及其应用

本文对甲醛的物理化学性质做了简单的介绍,并详细地介绍了甲醛聚合的原理,阐述了甲醛阻聚剂的阻聚原理、发展趋势、应用现状和使用过程中注意的问题,并对使用新型高效阻聚剂的经济效益做了分析,指出新型高效阻聚剂具有良好的应用前景和经济效益。     

立足大西南广阔的市场着力开发再生铝资源

主持：王真见先生。再生铝行业的不少同行对你在西南的重庆搞再生铝项目给予了高度的评价。再生金属分会的同志也多次到这里来考察再生铝行业，但我却是第一次来。这次亲眼看到这里巨大的市场。在前不久的《中国有色金属报》上曾经有人专门对重庆再生铝的市场有过一个详细的报道。认为在重庆有着广阔铸造铝合金市场潜力。而且你在这里干得有声有色。：年产10万吨的再生铝项目进展十分顺利。铸造铝合金的产品品种已经达到了十多个。产品销往西南地区和全国市场。这次来。看到了你们再生铝项目的一期工程正在有条不紊地进行，员工宿舍建设得整洁宽敞。二期工程的车间已经完成了主体工程。正在进行炉窑的安装和环保设施建设，各种铝合金产品正源源不断地走向市场。请给我们介绍一下你们这些年来的发展情况。     

搅拌槽内传质与反应动力学及其在染料废水脱色中的应用

实验研究了搅拌槽反应器内染料(活性艳红K-2BP)的臭氧氧化脱色过程.考察了溶液pH、臭氧流量、搅拌速度对臭氧脱色过程的影响.结果表明,臭氧脱色过程符合一级反应动力学,脱色过程中自由基反应起到主要作用;提高臭氧流量和搅拌速度能够显著加快脱色速度;通过对臭氧传质的测量和八田数Hα的计算,指出随着搅拌速率的增加,反应动力学区区域由慢速动力学区域转变到中速反应动力学区域.     

新型阳离子紫外光引发剂碘锚盐的光谱表征及分析

采用紫外光谱法(UV)分析新型阳离子光引发剂二甲苯基碘六氟磷酸盐。系统研究了UV法测试条件,采用氯仿重结晶提纯样品、以无水乙醇为溶剂、在λmax=236 nm测吸光度,ε=1.8421×104L.mol-1.cm-1,线性范围为1~80 mg.L-1,加标回收率为99.0%。     

基于CAN总线的集装箱正面吊车防前倾控制设计

介绍基于CAN总线通信的正面吊车的防前倾控制系统的工作原理,软硬件组成及实现方案。通过检测举升缸的压力,利用力矩平衡公式从而得出当前位置正面吊所挂集装箱的质量,利用该质量与该位置处允许的最大质量进行比较,从而实现正面吊的防前倾功能。     

基于SolidWorks和SQL的管壳式换热器辅助设计软件开发

为解决现有管壳式换热器结构设计配置多、设计周期长的难题,提出了结合SolidWorks软件参数化设计与SQL数据管理的管壳式换热器辅助设计软件开发。先采用"自顶向下"的设计思想建立不同管壳式换热器总成的SolidWorks骨架模型,利用SQL数据库对换热器产品零/部件选型、标准零件数据信息进行管理,然后以VB. NET调用SolidWorks API函数,实现不同型号管壳式换热器快速设计与工程出图。实践表明:所开发的软件可覆盖所有常规管壳式换热器不同型号产品的快速设计,换热器的平均设计周期可由16工时降至4工时,有效节省设计时间和开发成本,提高设计效率。     

冷轧冲孔机设计及应用研究

本文针对生产中不同宽度冷轧带钢焊缝处跟踪不良问题,采用计算分析及现场现有设备现状相结合的方法,改进原来带钢边部冲孔的方法,采用中间冲孔的工艺,达到准确跟踪、保证冷轧生产连续化的目的。