板材成形新技术及其发展趋势(Ⅰ)

近些年来,面对全球化的竞争,越来越需要小批量、多样化、周期短的新的成形技术.薄板成形技术在成形工艺中占有很重要的地位,其多样化趋势已经变得越来越明显,出现了多种加工方法,它对将来的工业结构和产品的生产技术将是一场革命.文中介绍了变压边力技术、成对液压成形技术、粘介质成形技术、无模分层成形技术等几种柔性化程度高的板材成形技术及其发展趋势.     

微米级空心玻璃微珠三相泡沫稳定性研究

基于水成膜泡沫灭火剂(AFFF),用微米级空心微珠颗粒作为泡沫稳定剂,制成三相泡沫,并研究了泡沫组成因素对发泡能力和泡沫稳定性的影响。采用控制变量法,研究了颗粒浓度、颗粒粒径、AFFF原液浓度对发泡倍数和析液时间的影响。颗粒加入对发泡能力有抑制作用;因为颗粒存在影响,三相泡沫的发泡能力随AFFF原液浓度增大而减小;40μm粒径颗粒的抑制作用相对20μm和60μm颗粒最小。颗粒浓度和AFFF原液浓度增加,能够提升三相泡沫稳定性,且泡沫析液时间随颗粒浓度增加呈指数规律变化。当AFFF原液浓度为3.0%、颗粒浓度为9%左右时,三相泡沫稳定时间约为两相泡沫的3倍,该配方三相泡沫有较好的稳定性。     

Efficiency characterization of fire extinguishing compound superfine powder containing Mg(OH)2

To improve the fire extinguishing efficiency of existing dry powders, a new type of superfine dry powder was prepared using magnesium hydroxide as an additive. In our study, a thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to analyze the thermal decomposition of the synthesized powders. The temperature of thermal decomposition, weight loss, and other thermodynamic parameters of the fire extinguishing powders were analyzed to explain the performance advantages of the compound superfine powder. Through a small-scale fire experiment, the physical parameters of the extinguishing process—such as extinguish time, powder dosage, smoke concentration, and minimum extinguishing concentration—were quantified for the suppression of a diesel fire using the different powders; these parameters were used to evaluate the fire extinguishing capacity and toxic gas suppression ability of the powders. TGA demonstrated that the compound superfine powder decomposed more quickly and its thermal decomposition process was much shorter than those of the other powders. The DSC data indicated that the compound superfine powder could decrease the characteristic temperature at each stage and thus the powder absorbed the flame's heat more quickly and suppressed flame propagation. The fire extinguishing test demonstrated that the consumption of the three types of fire extinguishing powder decreased with an increase in the driving pressure, and the order of powder dosage was as follows: commercial dry powder > superfine powder > compound superfine powder. Similarly, the order of minimum extinguishing concentration was as follows: commercial dry powder > superfine powder > compound superfine powder. Furthermore, the compound superfine powder exhibited a greater capacity for controlling toxic and harmful gas emissions.     

远程氩等离子体提高PVC生物填料挂膜性能的机理研究

采用接触角测定、电子扫描电镜（SEM）和X射线光电子能谱（XPS）研究了远程氩等离子体表面改性前后PVC填料表面结构性能的变化,以揭示远程氩等离子体提高PVC生物填料挂膜性能的机理,并对表面改性前后PVC填料进行了细菌挂膜试验.同时,利用＂远程等离子体＂场,评价了等离子体表面改性中电子、离子、自由基的贡献.结果表明,远程氩等离子体可以通过将含氧基团和含氮基团引入PVC填料表面,使其表面极性改变,提高表面润湿性能,使得填料的挂膜性能提高,从而增强了PVC填料的生物亲和性,加强了微生物的附着、固定作用.远程氩等离子体可以在一定程度上抑制电子、离子的刻蚀作用,强化自由基反应.     

模拟酸雨及其活化Al~（3＋）构成的复合污染对中小型土壤动物的毒杀效果

酸雨可引起土壤中铝离子的活化而造成铝毒问题,因此酸雨及其活化的金属铝离子势必造成对土壤中小型动物的复合污染与影响。为此,通过室内模拟试验,研究3种优势土壤动物直接暴露在4种不同酸度的模拟酸雨和4种不同铝离子浓度梯度组合而构成的复合污染处理条件下的死亡率,以探明酸雨通过降低土壤酸度同时活化Al3＋对土壤动物的叠加影响效应。研究结果表明：弹尾目、线虫、蜱螨目等土壤动物直接暴露在酸水和铝离子的复合溶液中,其死亡率总体上均会随着酸水pH值的降低和Al3＋离子浓度的升高而增加。通过单因素和双因素方差分析还发现,不同类群的土壤动物对模拟酸雨pH和溶液中Al3＋含量的敏感性各不相同,其中酸水和铝离子复合胁迫对线虫和蜱螨目动物死亡率的影响并没有表现出明显的交互作用,但对弹尾目土壤动物死亡率存在显著的交互作用影响。     

Energy Saving in Building Construction in China: A Review

Abstract

China is a developing country experiencing rapid economic growth. In recent years, increased urbanization has caused a tremendous rise of the energy consumption of buildings, and a corresponding need is to save this energy. In this article, the technologies and laws relative to building energy saving in China were presented which include building construction, the compound building energy system, policies, and the law etc. In order to fulfill the three stages of energy saving plan in building construction in China, the principal methods for developing building energy saving are introduced.     

复合式厌氧污泥床反应器处理城市生活污水的研究

复合式厌氧污泥床反应器是一种改进的厌氧处理工艺，可有效去除城市生活污水中的污染物，并提高了污水的可生化性，是一种较为理想的城市污水强化一级处理工艺。本文对该工艺，装置的特点和效果进行分析,并展望其应用前景。     

板料成形过程数值模拟中的动态接触条件处理

为了解决板料成形过程数值模拟中非线性边界条件问题,本文提出并建立了控制约束的描述方法、接触结点、确定的新方法——垂足法、计算接触应力的剪应力法、以及处理非线性滑动接触边界条件的降阶-摩擦载荷迭代法.经实际模拟计算,证明了这些方法的正确性.     

金属爆炸加工家族的新成员——金属容器无模爆炸加工

简述了金属爆炸加工的分类,着重叙述了无模金属爆炸成形的技术优越性、应用及前景.     

我国煤炭行业潜在危机与现实矿难的成因和对策

针对我国煤炭行业矿难频发,尚未有效遏制的现状,从对行业现实矿难的统计数据和潜在危机的现象分析入手,运用系统理论的观点,根据煤炭行业的复杂系统特征进一步分析危机和矿难形成的原因和机理。笔者认为,煤炭系统的危机和矿难是由系统运行过程中的矛盾和风险演变而来的,行业内部结构失衡是危机形成的内在因素,造成系统处于病态运行状态、危机潜伏;能源需求的非理性是危机形成的外部因素,造成系统病态运行加剧、危机加重;矿难则是处于危机状态的煤炭系统运行过程中剧烈波动而产生的突发危机事件。根据分析和研究所得的结论,提出必须纳入煤炭内部系统、纳入国家能源系统和宏观经济系统中,对煤炭行业危机和矿难进行多层次宏观层面的调控并采取新的对策。