鼓风机叶轮快速断裂的检测及失效分析

针对焦化厂鼓风机叶轮运行近15 d后产生穿透性裂纹、并延伸至叶轮半径2/3处的严重断裂事故,采用具有早期缺陷诊断功能的金属磁记忆新技术及其他多种手段,从宏观力学及微观机理角度对其进行综合性能评定及失效分析.研究结果表明,叶轮材料强度、韧性均过低,且韧性指标分散性大、同类型试样的韧性指标最大值与最小值之间相差3倍多;金相组织晶粒粗大,断口表现为脆性开裂.沿叶轮的断裂与非断裂面分别进行磁记忆扫描,磁场强度分析表明,断裂面内存在两处具有明显应力集中的危险源.分析表明,锻造及锻后热处理不良造成了快速疲劳断裂.最后,结合5年中3次叶轮断裂事故,对失效原因进行了相关性分析.     

Non-UV based germicidal activity of metal-doped TiO2 coating on solid surfaces

A stain-based screening method was developed to screen different catalyst coatings for their germicidal activity. A Baclight dead/live bacteria viability kit （invitrogen, molecular probes） was used for staining the cell. The screening was carried out following a standard procedure. This included loading cell suspension to solid surface and maintaining contact for 30 min, then staining with a mixture containing dyes. The stained cells were observed using an epifluorescent microscope and photographed with a CCD camera under UV. Metal-doped TiO2 coatings on AI plates were prepared and tested for non-UV germicidal activity without using UV. It was tested using model microorganisms such as Bakers Yeast （Saccharomyces cerevisiae）, Bacillus subtilis, Pseudomonas putida, and Escherichia coli. On the basis of the germicidal activity of catalyst and the degree of damage caused to the cells, the stained cells may appear green （viable）, green with red or yellow nuclei and yellow （compromised） or red （nonviable）. According to their stained color, cells were counted to calculate the percentage of dead, live, and compromised cells. Compromised cells are cells that grow very slowly after reculturing indicating a degree of reversible cell damage. Screening the germicidal activity using this staining method is accurate and efficient, and requires less time than the culture-based method. A modification to the procedure for measuring germicidal activity of rough surfaces or fibrous coatings was developed. Both TiO2 and metal-doped TiO2 （Ag, Pt, Au, Cu） possess non-UV based germicidal activity. The germicidal activity of TiO2 was found to be related with its wetting property and can be improved by UV irradiation before testing. It is not greatly affected by contact time, indicating a fast acting germicidal activity.     

型煤产业发展与提高

本文论述发展工业型煤产业的重要意义和技术质量保证,洁净煤技术是控制污染和节约能源,提高煤炭资源利用率的重要技术项目,将粉煤生产成型煤,为工业、民用提供洁净的燃料,既充分利用煤炭资源同时改善能源结构,又有显著的环保效益,国家把煤炭产业列入中国洁净煤技术有限发展项目,目前制约型煤产业的发展要造气型和燃烧型煤并举,同时有利于用户的节能效益。     

Origin of major ions in monthly rainfall events at the Bamenda Highlands, North West Cameroon

Rainwater characteristics can reveal emissions from various anthropogenic and natural sources into the atmosphere. The physico-chemical characteristics of 44 monthly rainfall events （collected between January and December 2012） from 4 weather stations （Bamenda, Ndop plain, Ndawara and Kumbo） in the Bamenda Highlands （BH） were investigated. The purpose was to determine the sources of chemical species, their seasonal inputs and suitability of the rainwater for drinking. The mean pH of 5 indicated the slightly acidic nature of the rainwater. Average total dissolved solids （TDS） were low （6.7 mg/L）, characteristic of unpolluted atmospheric moisture/air. Major ion concentrations （mg/L） were low and in the order K＋ 〉 Ca2＋ 〉 Mg2~ 〉 Na＋ for cations and NO3 〉〉 HCO3 〉 SO] 〉 CI- 〉 PO3- 〉 F- for anions. The average rainwater in the area was mixed Ca-Mg-SO4-CI water type. The CI-/Na＋ ratio （1.04） was comparable to that of seawater （1.16）, an indication that N a＋ and CI originated mainly from marine （Atlantic Ocean） aerosols. High enrichments of Ca2＋, Mg2＋ and SO2- to Na＋ ratios relative to seawater ratios （constituting 44% of the total ions） demonstrated their terrigenous origin, mainly from Saharan and Sahelian arid dusts. The K＋/Na＋ ratio （2.24）, which was similar to tropical vegetation ash （2.38）, and NO3 was essentially from biomass burning. Light （〈 100 mm） pre-monsoon and post-monsoon convective rains were enriched in major ions than the heavy （〉 100 mm） monsoon rains, indicating a high contribution of major ions during the low convective showers. Despite the acidic nature, the TDS and major ion concentrations classified the rainwater as potable based on the WHO guidelines.     

利用淀粉/PCL共混物作为反硝化固体碳源和生物膜载体的研究

以双螺杆挤出机制备了淀粉聚己内酯(PCL,polycaprolactone)共混物(SPCL5),研究了其浸出性能及吸水性能,并在序批试验中研究了其作为反硝化固体碳源和生物膜载体的特性。结果表明,SPCL5颗粒前3 d浸出的有机物浓度较高,随后逐渐降至1.31 mgL。SPCL5颗粒吸水率在1 d左右达到饱和,约为30.97%。SPCL5可作为固体碳源用于去除低碳氮比(CN)水中的硝酸盐。以活性污泥接种时,SPCL5颗粒在1 d后就有显著的脱氮效果。驯化结束后,SPCL5颗粒的平均反硝化速率(以N计)为0.020 8 mg(g·h)。剪切力是影响反硝化速率的重要因素,转速从70 rmin提高至140 rmin时,平均反硝化速率提升近1倍,达到0.040 3 mg(g·h)。进水NO3-N浓度为15~50 mgL时对反硝化速率无显著影响,反硝化为零级反应。红外光谱结果表明利用后的共混物中淀粉和PCL均发生了降解。     

蜂窝状整体式分子筛催化剂制备研究进展

分子筛催化剂已经广泛应用于化学工业、石油工业及环境污染处理等领域,其蜂窝状构型在选择性还原NOx方面具有广阔的应用前景。文章介绍了蜂窝状整体式分子筛催化剂制备的2种方式:固载化和自成型。对固载化法进行分类介绍,对不同固载方法制备的整体式催化剂的分子筛负载量进行对比,综述了载体种类、预处理方法和粘合剂的选择对固载化法制备整体式催化剂的影响,说明了固载化催化剂在应用上的优势及不足;阐述了自成型法制备蜂窝状整体式分子筛催化剂的优势,详细叙述了粘合剂的选择和用量、水含量、分子筛粒径分布、挤出成型过程和干燥过程对自成型蜂窝状整体式分子筛催化剂的物理化学性质和催化性能的影响,为整体式蜂窝状分子筛催化剂的开发提供了借鉴。     

基于蒙德法的固体火箭发动机水射流清理系统安全评价

安全性是固体火箭发动机水射流清理系统的第一要求。本文针对这一要求,采用蒙德火灾、爆炸、毒性指数评价法对固体火箭发动机水射流清理系统的4个单元进行了定量安全评价,得出了各单元的危险等级,并分析了水射流清理安全中的薄弱环节,进而提出了相应的安全措施,以为固体火箭发动机水射流清理系统的安全运行提供科学指导。     

青冰滩冰川水文特征初步分析

通过对青冰滩冰川的综合考察,对该地区2008-08-01日至08-31日的水文、气象以及水环境进行了连续观测。结果表明:冰川表面大量覆盖冰碛增加了冰川表面的反射率,加速了冰川消融;整个8月日均气温在8℃以下,气温的日较差较大,冰川消融期的降水以降雪和冰雹为主;冰川融水的电导率和溶解性固体相关系数可达0.98,两者与气温的相关度也可达到0.8以上。     

用固体力学化学理论研究岩土的力学化学行为——以成都龙泉紫色土为例

根据固体力学化学理论 ,提出用化学动力学方法研究岩土破坏及滑坡形成的机理 ,并以成都龙泉紫色土为例研究了在力与水协同作用下易滑土层的力学化学行为。实验表明 ,土长期抗剪强度降低的幅度与溶液的pH值有关 ,土的溶解速度与易溶盐含量有关 ,且溶解曲线略呈“S”型。这初步证明了龙泉紫色土破坏的力学 化学效应及其可能存在的自催化趋势。通过实验了解了力与水协同作用导致土破坏的力学化学规律 ,并将定量求解滑面长期抗剪强度与反应机理研究结合起来 ,为定量评价地下水和应力对岩土破坏机理这一滑坡学关键问题打下基础。     

深层过滤及其进展

本文阐述了深层过滤的机理,并详细分析了影响深层过滤效率的因素,在此基础上,系统地介绍了深层过滤设备的发展,分析了各种类型设备的优缺点,综述了国内外的一些现有设备,并结合当前国内设备的现状,指出了深层过滤设备的发展方向。本文旨在对深层过滤的研究及进展作一综述,以期对实际工作有一定的帮助。