微量元素锰在天津浅层孔隙含水介质中的吸附模式与迁移性能

为了解天津浅层孔隙含水介质对锰的吸附特征和锰在地下水中的迁移运动规律,利用宝坻和大港地区的2个钻孔岩芯配制7个土样,以Mn(NO3)2溶液模拟污染源,进行了室内静态吸附实验与动态淋滤实验,实验结果表明:(1)该地区浅部不同岩性地层对锰的吸附模式符合Langmuir等温吸附模式;(2)锰在淡水区含水层中迁移10m需要900d,在咸水区含水层中迁移10m需要1500d,个别地点锰的超标不会造成大面积污染。     

含水介质中渗透性突变的机理研究

通过盐度突变砂柱试验,对大沽河海咸水入侵区砂质含水层的渗透性突变进行了初步研究,并且探讨了咸淡水相互作用过程中渗透性降低的主要机制及对引起渗透性降低的主要影响因素进行分析。试验结果表明：盐浓度的突然降低会直接导致含水层渗透性发生急剧下降,同时在流出液中出现大量以粘土矿物为主的微粒物质;粘土矿物的含量和种类对含水介质渗透性降低幅度的影响非常大,盐度突变过程中,反应性粘土矿物对砂柱渗透性的影响要远远大于非反应性的微粒,且重量比为3％～4％时便可使砂柱的渗透系数降低到零。     

粒径对多孔介质中悬浮颗粒迁移—沉积特性的影响

粒径变化对悬浮颗粒在多孔介质中迁移—沉积过程影响的研究有重要意义。利用自主研发的砂层迁移—沉积模拟试验系统,研究不同粒径的悬浮颗粒在不同尺寸多孔介质中的迁移—沉积特性。结果表明,对于相同尺寸的多孔介质,随着悬浮颗粒粒径的增加,到达相对浓度峰值时间增加,而对应的相对浓度峰值降低;同时,对于相同粒径的悬浮颗粒,随着多孔介质尺寸增大,相对浓度峰值增加;另外,相对于多孔介质,悬浮颗粒粒径的变化对其迁移—沉积过程影响更为显著;随着多孔介质与悬浮颗粒粒径比增大,相对浓度的峰值和终值增大;根据粒径比不同将悬浮颗粒在多孔介质中的迁移—沉积类型划分为“滤饼过滤型”、“迁移—沉积型”、“自由迁移型”3种。研究结果为水源热泵回灌过程中悬浮颗粒在地层中的迁移—沉积特性进一步研究奠定了基础。     

多孔介质中沉积颗粒脱离特性试验研究

开展沉积颗粒在多孔介质中脱离过程试验对研究地下水源热泵回灌堵塞过程有重要意义。利用自主研发的砂层沉积–脱离模拟试验系统,研究增加渗流速度和改变渗流方向对多孔介质中已沉积颗粒脱离特性的影响。结果表明:在改变渗流速度大小条件下,渗流速度越大,已沉积的颗粒越容易发生脱离,到达悬浮颗粒相对浓度第二次峰值所需的时间越短,而达到二次峰值时所注入的水量接近;与改变渗流速度大小相比,用改变渗流方向的方式进行沉积颗粒脱离效果更为明显,到达二次峰值所需时间更短、水量更少,但随着时间增加,多孔介质中又会出现类似渗流方向改变前的堵塞现象;渗流条件变化后的初始阶段是已沉积颗粒脱离的主要时期。研究结果为水源热泵回灌过程中悬浮颗粒在地层中的沉积-脱离特性进一步研究奠定了基础。     

考虑加速效应的多孔介质中颗粒三维迁移模型研究

基于已有的颗粒一维迁移模型,建立一个考虑加速效应的颗粒三维迁移模型。通过Laplace变换和Fourier变换,给出点源和面源形式下的颗粒瞬时注入和周期形式注入问题的解析表达式,分析了点源瞬时注入情况下时间、距离、沉积系数、弥散系数等的影响机理。研究结果表明：随着时间增大,迁移颗粒浓度峰值逐渐减小,并且浓度峰值所对应的x坐标值逐渐增大。其次,浓度等值线在x-y平面上呈椭圆形状,在x方向上靠近颗粒注入口的等值线排列较密,远离注入口的等值线排列较疏。随着时间增大,低浓度等值线的范围逐渐向四周扩大,高浓度的等值线的范围逐渐缩小。另外,沉积系数越大,浓度等值线的范围越小。然而,随着x方向的弥散系数增大,等值线在x方向上逐渐向两侧拉长,而等值线在y方向上的范围逐渐缩小。     

中碱玻璃纤维在不同PH介质中稳定性的研究

本文对中碱玻璃纤维在Ca(OH)2和Mg(OH)2过饱和溶液、普通砖酸盐水泥、高铝水泥、氯氧镁水泥等不i同PH介质中的稳定性进行了研究。     

温度和pH对多孔介质中悬浮颗粒渗透迁移的影响

基于悬浮颗粒迁移的经典模型,在颗粒沉积动力学方程中考虑释放效应,求解了瞬时注入情况下悬浮颗粒的一维迁移问题的解析解,同时对两种不同悬浮颗粒（硅微粉和聚苯乙烯微球）进行室内土柱试验,得到不同pH（4,7,10）、不同温度T（20℃,30℃,40℃）和不同流速（0.042,0.127,0.212 cm/s）下的迁移曲线。利用解析解对试验数据进行拟合并确定迁移参数,讨论了温度、流速对迁移参数的影响。研究表明：温度、pH、颗粒种类是影响多孔介质中悬浮颗粒迁移的重要因素,当pH=7,T≤30℃时,悬浮颗粒排斥力起主导作用,pH=7,T>30℃时,布朗运动占主导作用;同时,随着流速的增大,水动力效应增大,温度对浓度峰值的影响不明显;随着pH的增大,聚苯乙烯微球在不同温度时的迁移曲线规律与硅微粉不同。     

主成分分析法识别岩溶多重介质含水系统水化学和水动力特性——以贵州后寨岩溶典型小流域为例

基于主成分分析,以贵州后寨典型岩溶含水系统为例,对该区1995年8月到1996年8月的10个代表性站点的20个变量进行分析,结果表明,前两个主成分综合携带了全部信息的89．3％。从变量的主成分判别平面图上得出第一主成分F1主要由Ca^2＋、SIc（方解石饱和指数）、SId（白云石饱和指数）、HCO3^-、总硬度、Mg^2＋决定,第二主成分F2主要由K^＋＋Na^＋、Cl^-、SO4^2-、HCO3^-,SO4^2-、TOD、水温等决定;水流流经地层的岩性是后寨流域内岩溶含水系统水化学类型和各种水化学参数在空间和时间上变化的主要控制因素,次要因素是地下水的水动力条件特别是地下水的径流深度。水文地球化学信息对地下水系统的水动力特征分析具有指示意义,而主成分分析法耦合水动力和水化学方面的信息,为深入了解岩溶含水系统水动力化学特征提供了一种途径。     

储油罐在不同油品沉积液中腐蚀的电化学研究

通过电化学极化的测量方法 ,研究了碳钢储油罐在不同成品油沉积液中的相对腐蚀性 .得出碳钢在不同油品沉积液中的腐蚀速度有明显差别 ;沉积液的酸碱度不同 ,对油罐的腐蚀也有较大影响 .     

塑胶跑道抗老剂BHT在非固体原料中含量与成品中释放量关系探究

建立了气相色谱-质谱法测定塑胶跑道非固体原料中2,6-二叔丁基对甲苯酚(BHT)含量的测试方法,在(1～100)mg/L范围内,方法线性相关系数R²=0.99795,检出限为0.012g/kg,定量限为0.040g/kg,RSD在(1.29～2.56)%。将含有BHT的非固体原料制作成塑胶跑道成品,用GB 36246-2018中总挥发性有机化合物(TVOC)释放量测试方法测试BHT释放量。建立非固体原料中BHT含量与成品中BHT释放量的相关性,二者具有较好的线性关系,线性相关系数R²=0.96965。     

颗粒物尺度对滤料过滤性能的影响

介绍了不同学者对滤料过滤机理的研究结果,实验研究了颗粒物尺度对粗、中、高效滤料过滤效率和过滤阻力的影响,对合理选择空调系统过滤材料提出了建议。     

Flame size, heat release, and smoke points in materials flammability

The concept of using the flame size as a surrogate for heat release rate (HRR) has been explored. A technique for simultaneously obtaining the HRR, flame size (height and area), and the smoke point of the flame solely from visual images has been developed. The technique has been demonstrated on gaseous flames (methane, propane, ethylene, and propylene) and explored for five burning solid polymers. Estimations of the flame area from images of the stoichiometric contour based on the CH chemiluminescent region of the flames yielded a good linear correlation with measured HRR, valid for all of the gaseous and solid compounds tested, for burning rates above or below the smoke point. In contrast, flame heights and luminous images (i.e., from soot emission) were confounded by differing behavior above and below the smoke point.     

Characteristics of particle removals in a compressible media filter system

The ability to adjust the properties of the filter medium by altering the degree of the medium compression is important because the different porosities in media affect the ideal filter performance according to the properties of influent wastewater. This study therefore focused on the particle size distribution (PSD) of compressible media filter (CMF) effluents depending on the compression ratio (0–30%) and the filter bed depth (Layers 1–5) in order to evaluate the CMF performance. The results showed that the removal efficiency for particles larger than 10 µm was more than 90% while that for particles smaller than 10 µm was less than 85% of removal efficiency. From the power law fit, substantial decreases in the number of large‐sized particles were observed in the PSD. Particle removal efficiencies increased along with the average compression ratio increase. Furthermore, the results demonstrated that each layer in the bed had a different role in the filter performance, and it was found that a filter bed of about 0.45–0.60 m would be needed for the production of the desired effluent quality in this study. The detachment phenomenon was observed in particles larger than 5 µm, especially in 5–15 µm particles.     

氧化铁胶体与黏土矿物的交互作用及其对黏土土性影响

以湛江黏土为研究对象,采用选择性化学溶解法,利用浸泡法、改进型渗透仪与柔性壁渗透仪除去土中游离氧化铁、无定形氧化铁和络合铁胶体,比较分析除去氧化铁胶体前后土的物理与力学性质指标、矿物成分以及结构变化特点,探讨氧化铁胶体的界面活性、胶结特性及其与黏土矿物的交互作用。结果表明,湛江黏土的结构强度受黏土矿物——氧化铁胶体的电性引力和镶嵌孔隙的氧化铁胶结状态的控制是导致其具有高灵敏性、强结构性的根本原因。氧化铁胶体对湛江黏土的水稳性、稠度、黏附性、渗透性、压缩性、灵敏性、结构强度均有重要影响。氧化铁胶体与黏土矿物的交互作用的本质并不是通过改变和破坏矿物晶格结构来改变黏土矿物性质,而是通过改变土颗粒间的联结状态及粒间力来控制微观结构形态,进而影响土的基本性质。氧化铁胶体对土性的影响程度与其赋存状态、老化结晶程度、水化程度密切相关,除了游离氧化铁、无定形态的氧化铁也是构成湛江黏土胶质联结的重要组成部分。     

后媒体时代的建筑媒体与媒体建筑

讨论了现代社会媒体对建筑行业的冲击以及媒体建筑和建筑媒体之间的联系和互动,评价了当今社会媒体建筑存在的意义和发展走向,指出媒体建筑作为一种新的建筑存在方式所具有的前瞻意义。     

Determination of fungal spore release from wet building materials

The release and transport of fungal spores from water-damaged building materials is a key factor for understanding the exposure to particles of fungal origin as a possible cause of adverse health effects associated to growth of fungi indoors. In this study, the release of spores from nine species of typical indoor fungi has been measured under controlled conditions. The fungi were cultivated for a period of 4-6 weeks on sterilized wet wallpapered gypsum boards at a relative humidity (RH) of approximately 97%. A specially designed small chamber (P-FLEC) was placed on the gypsum board. The release of fungal spores was induced by well-defined jets of air impacting from rotating nozzles. The spores and other particles released from the surface were transported by the air flowing from the chamber through a top outlet to a particle counter and sizer. For two of the fungi (Penicillium chrysogenum and Trichoderma harzianum), the number of spores produced on the gypsum board and subsequently released was quantified. Also the relationship between air velocities from 0.3 to 3 m/s over the surface and spore release has been measured. The method was found to give very reproducible results for each fungal isolate, whereas the spore release is very different for different fungi under identical conditions. Also, the relationship between air velocity and spore release depends on the fungus. For some fungi a significant number of particles smaller than the spore size were released. The method applied in the study may also be useful for field studies and for generation of spores for exposure studies.     

The inhibitory effects of silver nanoparticles, silver ions, and silver chloride colloids on microbial growth

Emerging nanomaterials are of great concern to wastewater treatment utilities and the environment. The inhibitory effects of silver nanoparticles (Ag NPs) and other important Ag species on microbial growth were evaluated using extant respirometry and an automatic microtiter fluorescence assay. Using autotrophic nitrifying organisms from a well-controlled continuously operated bioreactor, Ag NPs (average size=14+/-6 nm), Ag(+) ions (AgNO(3)), and AgCl colloids (average size=0.25 microm), all at 1mg/L Ag, inhibited respiration by 86+/-3%, 42+/-7%, and 46+/-4%, respectively. Based on a prolonged microtiter assay, at about 0.5mg/L Ag, the inhibitions on the growth of Escherichia coli PHL628-gfp by Ag NPs, Ag(+) ions, and AgCl colloids were 55+/-8%, 100%, and 66+/-6%, respectively. Cell membrane integrity was not compromised under the treatment of test Ag species by using a LIVE/DEAD Baclight bacterial viability assay. However, electron micrographs demonstrated that Ag NPs attached to the microbial cells, probably causing cell wall pitting. The results suggest that nitrifying bacteria are especially susceptible to inhibition by Ag NPs, and the accumulation of Ag NPs could have detrimental effects on the microorganisms in wastewater treatment.     

不同滤料对丹江口水库水的过滤效果研究

以丹江口水库中试基地的沉淀池出水作为试验用水,对比研究了细石英砂单层滤料、粗石英砂单层滤料、无烟煤单层滤料及无烟煤-石英砂双层滤料的过滤效果。结果表明,4组滤柱对浊度的去除效果相近,但无烟煤-石英砂双层滤柱受进水浊度变化的影响较小,抗冲击能力较强,出水浊度相对稳定;无烟煤-石英砂双层滤柱与无烟煤滤柱对有机物的去除效果优于细石英砂与粗石英砂滤柱,无烟煤-石英砂双层滤柱与无烟煤滤柱对CODMn的去除率分别为(31.45±10.39)%和(28.23±9.15)%,对UV254的去除率分别为(13.05±5.3)%和(14.23±4.97)%;细石英砂滤柱水位增长最快,且运行周期最短,无烟煤-石英砂双层滤柱与无烟煤滤柱水位增长相对较慢,运行周期是细石英砂与粗石英砂滤柱的2～3倍。     

混凝土中介质迁移表观动力学初探

基于 Fick 第二定律和 Darcy 定律,对混凝土中介质迁移表观动力学模型进行了理论推导,讨论了该模型对钢筋混凝土耐久性研究与设计的意义.