Effects of calcium substitute in LaMnO3 perovskites for NO catalytic oxidation

La1-x Cax MnO3 (x=0-0.3) perovskite-type oxides were synthesized by citrate sol-gel method. The physical and chemical properties were characterized by X-ray diffraction (XRD), Brumauer-Emmett-Teller method (BET), X-ray photoelectron spectroscopy (XPS), NO+O2 -TPD (temperature-programmed desorption), activated oxygen evaluation and H2 -TPR (temperature-programmed reduction) technologies. The results showed that NO catalytic oxidation activity was significantly improved by Ca substitution, especially for lower temperature activity. The La0.9 Ca0.1 MnO 3 sample showed the maximum conversion of 82% at 300 oC. The monodentate nitrates played a crucial role for the formation of NO2 . The reducibility of Mn 4+ ions and reactivity of activated oxygen were favorable for the catalytic performances of NO oxidation.     

仓储立体库纱锭智能配重打包方法研究

传统纱锭配重打包大多由人工完成或者由机器完成部分工序。人工重复工作易疲劳,打包效率低,并 且纱锭重量误差大。无法满足纱锭交易市场要求的重量控制在较小误差范围。本文研究一种纱锭配重组合打包 的立体库方法,首先在传统纱锭流水线基础上优化,设计出立体仓储提高库存与利用率。对纱锭流水线动态称 重后跟踪出入库,利用配重相关理论和智能算法,将纱锭分拣配重打包,实现纱锭动态运输。针对人工配重精 度不高的问题,通过比较现有的重量组合法,给出改进的回溯配对方法,横向纵向动态遍历仓储中不同重量的 纱锭。经过仿真实验表明,改进的智能配重方法能大大提高纱锭配重效率,可实际运用于企业生产中。     

基于Fluent的压裂车液压油散的翅片散热优化

随着压裂技术水平的提高和油气井的大规模开发，低功率压裂泵已逐步淘汰。大功率、超高压、大排量和智能化已成为国内外压裂车的主要特点。当满足这些条件时，压裂车散热器便不可避免地需要具有高散热效率。基于工程传热学，对液压油散进行几何模型和数学模型的构建，分析了压裂车液压油散的内部结构。利用 Fluent对不同的隔板间距和不同翅片厚度和节距的液压油散模型进行了仿真分析，并运用MATLAB对数据进行插值拟合处理，最终提出了一种提高压裂车油散的散热效率结构。