腹水浓缩回输术治疗顽固性腹水的疗效研究

目的探讨腹水浓缩回输术治疗肝硬化顽固性腹水的疗效。方法采用病例对照研究,在常规护肝利尿基础上,对67例进行腹水浓缩回输治疗,观察治疗前后临床表现、生化指标的变化及并发症发生率。结果经腹水浓缩回输术治疗后的病例,体重、腹围均明显好转,尿量增多,肾功能改善,白蛋白明显提升,并发症发生率降低,显效率明显提高。结论能有效地减轻患者痛苦,节约输注外源性白蛋白的费用,减少利尿剂用量。     

One step sintering of homogenized bauxite raw material and kinetic study

A one-step sintering process of bauxite raw material from direct mining was completed, and the kinetics of this process was analyzed thoroughly. The results show that the sintering kinetics of bauxite raw material exhibits the liquid-phase sintering behavior. A small portion of impurities existed in the raw material act as a liquid phase. After X-ray diffraction analyses, scanning electron microscopy observations, and kinetics calculations, sintering temperature and heating duration were determined as the two major factors contributing to the sintering process and densification of bauxite ore. An elevated heating temperature and longer duration favor the densification process. The major obstacle for the densification of bauxite material is attributed to the formation of the enclosed blowhole during liquid-phase sintering.     

Oxide coating mechanism during fluidized bed reduction: solid-state reaction characteristics between iron ore particles and MgO

Experiments on the solid-state reaction between iron ore particles and MgO were performed to investigate the coating mechanism of MgO on the iron ore particles’ surface during fluidized bed reduction. MgO powders and iron ore particles were mixed and compressed into briquettes and, subsequently, roasted at different temperatures and for different time periods. A Mg-containing layer was observed on the outer edge of the iron ore particles when the roasting temperature was greater than 1173 K. The concentration of Fe in the Mg-containing layer was evenly distributed and was approximately 10wt%, regardless of the temperature change. Boundary layers of Mg and Fe were observed outside of the iron ore particles. The change in concentration of Fe in the boundary layers was simulated using a gas–solid diffusion model, and the diffusion coefficients of Fe and Mg in these layers at different temperatures were calculated. The diffusion activation energies of Fe and Mg in the boundary layers in these experiments were evaluated to be approximately 176 and 172 kJ/mol, respectively.     

一种基于PIC16C54的双联气泵控制系统

简要介绍一种应用于气冷式高温工业电视的以 Ｐ Ｉ Ｃ１６ Ｃ５４ 微处理器为核心的双联气泵控制系统     

精炼钢包渣对合成镁钙系耐火材料侵蚀研究

以轻烧镁粉和轻烧白云石粉为原料，合成镁钙砂并制砖；利用高温显微和岩相分析，将材料抗水化性与抗渣性结合起来，研究了精炼钢包渣对合成镁钙系耐火材料的侵蚀。结果表明：合成镁钙系耐火材料对碱性渣有很好的抵抗性；少量添加剂既可提高抗水化性又不降低抗渣性。     

连铸中间包耐火材料的冲蚀特性与控流装置的优化设置

中间包内耐火材料的损毁是化学反应、热应力与钢液流动的协同作用所致,中间包内控流装置发生侵蚀的主要原因是钢液对耐火材料的冲蚀.对设置有湍流控制器、挡渣堰、挡渣坝的中间包耐火材料的冲蚀特性进行数值模拟计算与分析,结果表明,中间包内冲蚀最严重的部位是在湍流控制器及冲击区包壁上部1/3处,其次是挡渣堰迎向钢液流动一侧壁面;随着挡渣堰与钢液入口距离的增加,钢液对挡渣堰、挡渣坝的冲蚀强度下降;根据停留时间分布(RTD)曲线设置中间包控流装置时,应考虑钢液对耐火材料的冲蚀特性.     

臭氧氧化难降解废水生化性改变研究评述

将臭氧氧化难降解废水过程划分为生化性改变阶段和有机物去除阶段,并分析了近年来臭氧氧化废水生化性改变阶段的研究成果.发现在有机物去除率较低条件下,废水的污染物质含量,色度,UV254,SUVA和3维荧光光谱等指标变化显著,分析认为引起以上指标变化的原因是难降解有机物分解为小分子易降解有机物.生化性改变阶段废水中主要进行难降解有机物的分解反应,而非矿化反应.多位研究者GC-MC和分子量分布的实验结果表明,生化性改变阶段废水中小分子有机物种类和数量都明显增加.废水生化性指标和生化处理的相关研究报道进一步证明了生化性改变阶段废水生化性改善的事实.建议在今后研究中,以提高生化性改变阶段臭氧氧化反应效率为重点,破解难降解有机废水处理的难题.     

免烧成硼酸铝-碳化硅耐火材料的性能

以碳化硅为主要原料,分别以酚醛树脂、氧化铝和氧化硼粉体作为常温和高温结合剂,研究了免烧成硼酸铝-碳化硅耐火材料的体积密度、抗折强度和抗热震性.结果表明:当酚醛树脂的质量分数为5%时,耐火材料的体积密度和抗折强度分别为266g·cm-3和13~21MPa;在960℃烧结之后,主要物相为SiC,Al2O3,Al4B2O9;当高温结合剂的质量分数为75%时材料的体积密度最大,为255g·cm-3;当高温结合剂的质量分数为125%时,材料的抗折强度最大,为19MPa;经过5次高温热震后,高温结合剂的质量分数为75%时材料抗热震性较好,强度损失率为25%.     

纳米技术在耐火材料中的应用研究

简要介绍几种无机纳米材料前驱体及粉体的制备，详细介绍了纳米前驱体及粉体在纳米复合耐火材料制备过程中的应用。初步研究表明，将纳米粉体或其前驱体引入耐火材料中，既可起到更紧密的充填作用，又能起到促进烧结、改变内部结构的作用，还能提高反应活性和催化作用，可进一步提升耐火材料的性能。     

竖炉冶炼铬铁新工艺炉渣对耐火材料侵蚀的理论分析

针对竖炉冶炼铬铁新工艺炉渣为典型酸性渣的特点,应用CaO-Al2O3-SiO2、MgO-Al2O3-SiO2三元系相图、CaO-Al2O3-SiO2系在1 500℃等温截面图,比较、分析了新工艺炉渣、高炉炼钢渣以及电炉冶炼高碳铬铁渣对硅酸铝质耐材侵蚀的影响,以此在理论上初步确定新工艺炉渣对耐材的侵蚀程度。