机器学习在材料服役性能预测中的应用

针对材料服役性能预测存在误差大、计算复杂、适用性差等问题,提出了基于数据挖掘的机器学习预测方法。首先阐述了机器学习的应用流程,并总结了常用模型原理及其在材料性能预测中的应用。然后采用多种机器学习模型对RPV钢的辐照性能进行预测,并通过Stacking集成方法提高了模型的预测精度。结果表明,机器学习可用于材料服役性能预测,具有较高的预测精度和可靠性。根据材料服役数据的不同特征选择合适的学习模型,同时进行模型融合和参数优化,可有效提高模型的预测精度及运算速度。     

车用高分子材料不同地区户外曝晒试验相关性研究

目的将3种高分子材料以及3种车用外饰材料分别投放在中国海南琼海和美国佛罗里达州2种典型湿热环境中进行户外曝晒试验,研究气候相似的2种地区的试验相关性。方法通过测试相同时间间隔下不同材料在2处试验场曝晒过程中的黄变程度,表征材料的老化现象。采用斯皮尔曼等级相关系数的统计方法,研究材料在2个地区相同时间节点的试验结果的相关性,并利用时间同轴的作图方法比较2个地区严酷度的差异。结果琼海与佛罗里达州2个地区在各个时间节点的相关系数接近于1,且在材料黄变方面呈现一定比例关系。结论琼海和佛罗里达州2个地区的试验结果呈现出较好的相关性,且严酷度比值约为琼海︰佛罗里达=1︰1.19。     

有机阳离子型电荷杀菌材料研究现状及展望

细菌等致病微生物可通过空气、水、土壤、食物等途径在自然界中传播,易对人体造成诸如肺结核、淋病、鼠疫等健康风险。目前广泛使用的灭菌方式包括紫外线、臭氧、氯气、电荷等物理或化学方法,其中电荷杀菌因具有无组织毒性的优点被广泛使用。研究表明：有机阳离子型电荷杀菌材料相比传统的金属离子杀菌材料具有抗菌效能优异、不产生耐药性、生物安全性高等优点,其杀菌性能受分子大小、烷基链、反离子类型、电荷密度等因素影响。本文系统综述了目前有机阳离子型电荷杀菌材料的类型、结构特征、杀菌性能及影响因素,抗菌机理及应用现状,分析了其存在的问题和发展方向,为有机阳离子型电荷杀菌材料的后续研究和应用提供一定的借鉴和指导。     

硫酸含汞问题的追踪研究

以辽宁省最大的硫酸生产企业（辽西某锌厂）为研究对象，剖析了硫酸含汞问题的来源，论述了该厂原料、中间产品、最终产品、车间内外环境汞的污染状况。并论述了使用该厂硫酸的十大企业的中间产品、最终产品的含汞状况，给出了厂内外环境受汞污染的测定结果，研究表明含汞硫酸污染问题是急待解决的重要问题。     

复合材料静态处理煤矿高浓度含锰废水的研究

针对目前云南省某煤矿排放废水中Mn~(2+)超标的问题,利用一种新型复合材料进行除锰试验.该复合材料是纳米分子筛与硅藻土经合理复配后,掺入复配絮凝荆形成的.试验中优化了不同材料的复合方式、絮凝剂的复配比例与用量.利用复配的多孔材料,对云南某煤矿含有大量悬浮物、Mn~(2+)质量浓度为5.32 mg/L的黑色废水及Mn~(2+)质量浓度为42.mg/L的红褐色废水进行了Mn~(2+)去除效果研究.结果表明,黑色废水中Mn~(2+)去除率达到70%,出水pH值为7.9;红褐色废水中Mn~(2+)去除率达到91.0%,出水pH值为7.1.与此同时,还研究了废水中Fe~(3+)、固体悬浮物(SS)对Mn~(2+)去除效果的影响,废水中Fe~(3+)的存在使pH降低,并与Mn~(2+)产生竞争吸附,对复合材料除锰有不利影响,而SS的存在对Mn~(2+)的去除效果没有显著的影响.     

聚氨脂泡沫填缝剂生产工艺火灾危险性分析与对策

以聚氨脂泡沫填缝剂基本生产原理及其特点为基础,对生产原料进行火灾危险性分析,结果表明:该类生产场所的火灾危险等级应划分为甲类;提出聚氨酯泡沫填缝剂生产中存在的安全问题及原因;运用危险度评价法对聚氨脂泡沫填缝剂生产工艺的火灾危险性进行了定量的安全评价,得出聚氨脂泡沫填缝剂生产工艺的危险程度为高度危险;并从建筑设计、防火管理和生产工艺等方面提出了预防火灾事故发生的对策。     

Fatty acids and algal lipids as precursors of chlorination by-products

Six common algal fatty acids (FAs) with different numbers of double bonds, lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal cells were chlorinated to evaluate their potential in generating disinfection by-products (DBPs). The result showed that the more double bonds in the FAs, the higher the amounts of chloroform and dichloroacetic acid (DCAA) produced, but such a pattern was not observed for trichloroacetic acid (TCAA). Based on the previously reported composition of fatty acids in algal lipids, the DBP generation potentials of algal lipids were calculated. These predicted values were much lower than those measured in the chlorinated algal lipophilic fraction, suggesting unknown lipophilic fraction(s) served as potent DBPs precursors. Another calculation attempted to predict DBP production in algal cells based on algal lipid and protein composition, given quantified measured DBP production per unit algal lipid and proteins. The analysis showed that the observed DBP production was similar to that predicted (< 35% difference), suggesting that algal biochemical compositions may serve as a bioindicator for preliminary estimation of chloroform, DCAA and TCAA formation upon chlorinating algae.     

金属材料腐蚀疲劳研究进展

首先归纳了金属材料的腐蚀疲劳裂纹萌生机理和扩展机制,从材料自身因素、外界力学因素和环境因素三方面分析了腐蚀疲劳影响因素,简要介绍了环境腐蚀-疲劳载荷交互试验和环境腐蚀-疲劳载荷协同试验研究现状及重要性,并展望了金属材料腐蚀疲劳今后研究的重要方向,为金属材料腐蚀疲劳的试验开展、机理探索和工程应用奠定基础。     

Dissolved Ions of Trace and Major Elements and in Suspended Sediments in the Nile, Egypt

Dissolved ions and suspended participates from twelve water samples from Sohag (different localities) and Aswan (behind and below the High Dam) areas were collected along the River Nile, upper Egypt, which is at present affected seriously by pressure of population, intense industrial and agricultural activities, and atmospheric fallout. Eighteen trace and nine major ions in solution and fourteen metals in suspension were analyzed to establish whether elements are of anthropogenic or natural origin. Results of this study show that the Nile water was contaminated with high concentrations of dissolved lead, and with copper, nickel and mercury to a lesser extent, suggesting that these contaminants are generated from anthropogenic activities. the other dissolved ions in the Nile are of natural origin because their metal concentrations fall within the range of the normal background and average world dissolved values for inland waters. Results show that the usual constituents of suspended particulates in the Nile seem to be some metals (Cu and Zn) adsorbed on iron and manganese oxide/hydroxide. the results also reveal that most trace and major metal particulates increase from south to north due to activities associated with the dense population living along the Nile banks. No significant differences were observed between the chemical composition of trace and major elements taken on the east and west river Nile banks.     

HMX与低熔点含能材料混合物的热安定性研究

目的 研究环四亚甲基四硝胺(HMX)与2,4,6-三硝基甲苯(TNT)、2,4-二硝基苯甲醚(DNAN)、3,4-二硝基呋咱基氧化呋咱(DNTF)3种低熔点、高挥发性含能材料混合后的热安定性及相关性质.方法 将HMX与3种低熔点含能材料按照质量比1:1进行混合,采用动态测压热分析法(DPTA)、差示扫描量热法(DSC)...