易燃液体燃烧烟气在空间不同位置的沉积规律

在搭建的试验房间顶部及墙壁上布置一系列采样板,模拟火灾现场中易燃液体燃烧烟气的蔓延和吸附情况,然后定量提取采样板上吸附的烟尘,并利用GC/MS进行定量成分分析,根据采样板上烟气特征成分的含量,确定易燃液体燃烧烟气在不同空间位置的沉积规律,从而确定火场勘查中物证提取的最佳位置。试验结果表明,火源上部正对火源处为最佳提取位置,同时还可提取墙角处,以及距火源最近的壁面和顶面交汇处的烟尘。     

易燃液体放火案件物证分析技术的研究进展

将易燃液体放火案件中的火场物证分为液态物证、固态物证和气态物证三大类,分别总结介绍其特点、采集方法。结合国内外的标准规范,分别阐述易燃液体放火案件物证的提取技术,包括ASTM易燃液体残留物提取方法及其优化方法和分析鉴定技术,包括紫外光谱法、气相色谱法、高效液相色谱法和气相色谱/质谱联用法等的特点和研究进展。     

改性活性炭纤维吸附饮用水中卤乙酸的研究

采用化学法、微波法、负载铁离子法等对活性炭纤维(ACF)进行改性,考察了改性后的ACF对饮用水中卤乙酸的吸附效果及影响因素.结果表明,经负载-微波改性后的ACF对DCAA、TCAA的吸附效果最好;负载一微波改性ACF的最佳条件:微波功率为250 W、溶液配比为Fe3+:Fe2+=3:2,在此条件下,改性ACF对DCAA、TCAA的吸附量比改性前的分别提高了22.0%、6.2%;在竞争吸附条件下,负载一微波改性ACF对卤乙酸的吸附量明显小于单底质条件下的.     

烟气在不同材料表面沉积规律的研究

模拟火灾现场易燃液体(汽油)燃烧,在烟气上部放置不同载体材料采样板,提取采样板上的烟尘进行GC/MS成分分析.通过分析各采样板烟尘成分含量的多少确定各载体采样板的吸附能力,从而确定在火灾现场中提取何种材料表面的烟尘使检测结果最佳,有效地指导火灾现场中烟尘物证的提取部位,增强了鉴定的准确性和科学性.     

易燃液体放火物鉴定中干扰物排除的研究

本文根据作者多年来对火灾鉴定技术的研究和实践，从物证提取和物证鉴定两个方面，着重介绍了易燃液体放火火灾中的干扰物排除技术。     

活性碳纤维的电吸附性能

研究了活性碳纤维(ACF)表面结构、性质与其电吸附性能的相关性,并应用于有机污染物的电吸附去除.结果表明:对于SBET分别为791,1 003,1 314 m2/g的ACF虽然具有相似的孔径分布范围、相近的等电点和相同的表面微观结构,但SBET和微孔体积数的不同将导致ACF物理电阻值和表面电化学阻抗差异较大,从而造成ACF对有机物苯酚的电吸附效果明显不同.而且,ACF的电吸附性能受到吸附质的性质、初始浓度和介质pH值的显著影响.     

风化效应对火场中易燃液体鉴定的影响

为了解风化效应对易燃液体检验鉴定影响的研究进展,对国内外相关研究进行了梳理,介绍了风化效应对易燃液体原样及燃烧残留物的影响、易燃液体检验鉴定中风化干扰的排除和风化干扰与其他干扰的耦合三方面的内容,并对下一步的研究方向进行了展望。     

火场易燃液体检验鉴定国内外标准对比研究

对于使用易燃液体实施的放火,易燃液体的检验鉴定是认定火灾性质的关键,而相关物证检验鉴定标准的建设具有重要意义。为进一步完善我国相关标准建设,在对美国材料试验协会、澳大利亚标准委员会和我国易燃液体检验鉴定标准体系整体介绍的基础上,着重对中外4个标准中对易燃液体的种属分类、易燃液体残留物物证保存条件、易燃液体特征组分识别、干扰因素分析以及鉴定报告内容5部分进行了横向比较。结果表明,国内外易燃液体检验鉴定标准在具体鉴定程序上有所差异,国外标准在物证检材的保存、干扰因素的分析及鉴定报告的撰写等方面对我国标准的修订具有一定的借鉴性,研究结果可为我国火场易燃液体检验鉴定标准的完善提供重要参考和指导。     

活性碳纤维脱除空气中二氧化硫的研究与应用

本文采用四氯汞盐溶液吸收——盐酸副玫瑰苯氨比色法研究了活性碳纤维材料(ACF)对微量二氧化硫等气体的吸附性能。空气通过ACF材料后，二氧化硫的脱除率在46％以上。将其应用于家用恒温换气装置中，可有效脱除进入室内空气中的二氧化硫等有害气体，改善室内空气品质，保持室内空气清新、温度适宜。     

硫脲法提取金银试剂消耗研究

在定量研究硫脲法提取金银中硫脲、硫酸、氧化剂及添加剂的消耗基础上，考查体系中三价铁对硫脲的氧化还原反应过程，红外光谱分析硫脲在矿物表面的吸附状态及杂质配位影响等硫脲的主要消耗去向，探讨了消耗机理，提出了优化工艺。在不加氧化剂条件下，金的浸出率可达９８％以上，各试剂消耗可降到常规硫脲法的１／３到１／５以下。     

The effects of dissolved natural organic matter on the adsorption of synthetic organic chemicals by activated carbons and carbon nanotubes

Understanding the influence of natural organic matter (NOM) on synthetic organic contaminant (SOC) adsorption by carbon nanotubes (CNTs) is important for assessing the environmental implications of accidental CNT release and spill to natural waters, and their potential use as adsorbents in engineered systems. In this study, adsorption of two SOCs by three single-walled carbon nanotubes (SWNTs), one multi-walled carbon nanotube (MWNT), a microporous activated carbon fiber (ACF) [i.e., ACF10] and a bimodal porous granular activated carbon (GAC) [i.e., HD4000] was compared in the presence and absence of NOM. The NOM effect was found to depend strongly on the pore size distribution of carbons. Minimal NOM effect occurred on the macroporous MWNT, whereas severe NOM effects were observed on the microporous HD4000 and ACF10. Although the single-solute adsorption capacities of the SWNTs were much lower than those of HD4000, in the presence of NOM the SWNTs exhibited adsorption capacities similar to those of HD4000. Therefore, if released into natural waters, SWNTs can behave like an activated carbon, and will be able to adsorb, carry, and transfer SOCs to other systems. However, from an engineering application perspective, CNTs did not exhibit a major advantage, in terms of adsorption capacities, over the GAC and ACF. The NOM effect was also found to depend on molecular properties of SOCs. NOM competition was more severe on the adsorption of 2-phenylphenol, a nonplanar and hydrophilic SOC, than phenanthrene, a planar and hydrophobic SOC, tested in this study. In terms of surface chemistry, both adsorption affinity to SOCs and NOM effect on SOC adsorption were enhanced with increasing hydrophobicity of the SWNTs.     

Adsorption of tri- and tetra-chloroethylene from aqueous solutions on activated carbon fibers

Recently the contamination of groundwater by trichloroethylene and related compounds have become a new environmental problem. As the first step to clarify the feasibility of applying newly developed adsorbent, activated carbon fiber (ACF), to adsorption treatments of water taken from such a contaminated groundwater source, the adsorption equilibrium and the adsorption rate of trichloroethylene and tetrachloroethylene from aqueous solutions on four ACFs with different pore-size distribution were investigated. The adsorption capacities of ACFs having larger volume of micropores are larger than those of granular activated carbons (GACs) usually used at present. Also, the adsorption rate on ACFs is far more rapid in comparison with GAC adsorption because of smaller diffusion path.     

Dynamic pesticide removal with activated carbon fibers

Rapid small-scale minicolumn tests were carried out to simulate the atrazine adsorption in water phase with three pelletized pitch-based activated carbon fibers (ACF) and one commercial granular activated carbon (GAC). Initial atrazine solutions were prepared with pretreated ground water. Minicolumn tests showed that the performance of highly activated carbon fibers (surface area of 1700 m2/g) is around 7 times better than the commercial GAC (with surface area at around 1100 m2/g), whereas carbon fibers with medium activation degree (surface area of 1500 m2/g) had a removal efficiency worse than the commercial carbon. The high removal efficiency of the highly activated ACF is due to the wide-opened microstructure of the material, with an appreciable contribution of the low size mesopores, maintaining at these conditions a fast kinetic adsorption rate rather than a selective adsorbent for micropollutants vs. natural organic matter.     

室内空气中甲醛在ACF上的衍生反应动力学及其定量关系的研究

文章在对ACF的纳米空间结构及其载体功能特性以及ACF纳米结构上甲醛的衍生反应及其吸附/解吸原理,进行深入研究基础上,揭示了室内空气中甲醛在ACF上的吸附与解析动力学过程。根据Langmuir-Rideal定理,描述了甲醛与PFBHA-HCHO反应定量关系;推导出PFBHA-HCHO肟化合物浓度的反应速率与室内空气中甲醛浓度之间的一级反应线性回归方程,为定量检测室内空气中甲醛提供了理论依据。     

Adsorption of dissolved natural organic matter by modified activated carbons

Adsorption of dissolved natural organic matter (DOM) by virgin and modified granular activated carbons (GACs) was studied. DOM samples were obtained from two water treatment plants before (i.e., raw water) and after coagulation/flocculation/sedimentation processes (i.e., treated water). A granular activated carbon (GAC) was modified by high temperature helium or ammonia treatment, or iron impregnation followed by high temperature ammonia treatment. Two activated carbon fibers (ACFs) were also used, with no modification, to examine the effect of carbon porosity on DOM adsorption. Size exclusion chromatography (SEC) and specific ultraviolet absorbance (SUVA(254)) were employed to characterize the DOMs before and after adsorption. Iron-impregnated (HDFe) and ammonia-treated (HDN) activated carbons showed significantly higher DOM uptakes than the virgin GAC. The enhanced DOM uptake by HDFe was due to the presence of iron species on the carbon surface. The higher uptake of HDN was attributed to the enlarged carbon pores and basic surface created during ammonia treatment. The SEC and SUVA(254) results showed no specific selectivity in the removal of different DOM components as a result of carbon modification. The removal of DOM from both raw and treated waters was negligible by ACF10, having 96% of its surface area in pores smaller than 1 nm. Small molecular weight (MW) DOM components were preferentially removed by ACF20H, having 33% of its surface area in 1--3 nm pores. DOM components with MWs larger than 1600, 2000, and 2700 Da of Charleston raw, Charleston-treated, and Spartanburg-treated waters, respectively, were excluded from the pores of ACF20H. In contrast to carbon fibers, DOM components from entire MW range were removed from waters by virgin and modified GACs.     

硅藻土/竹炭复合材料的制备及孔结构表征

本研究以竹炭为主要原料,添加硅藻土,以硅铝复合物为粘结剂,经粘结造粒、表面包覆改性、高温煅烧等工艺,制备了一种新型硅藻土/竹炭复合材料。采用氮吸附法对其孔结构进行表征,结果表明,BET比表面积为142.563m2/g,总孔容为0.156cm3/g,相比竹炭,比表面积有所降低,但总孔容却提高了43.12%,意味着吸附容量增大了;孔隙分布也较合理,微孔率、介孔率和大孔率分别为44.23%、32.05%和23.72%,克服了硅藻土和竹炭孔径分布过窄的缺点。由此表明在竹炭中添加硅藻土制备介孔率高、孔径分布均匀、吸附容量大的吸附材料是一种可行的方法。     

CFRP布对不同截面混凝土柱加固性能分析

为了探究碳纤维增强复合材料(CFRP)布对不同截面混凝土柱的加固性能,以条带用量、条带净间距、条带净宽等参数为控制变量,设计并制作了3组钢筋混凝土柱,第1组试件为方形截面柱,第2组试件为T形截面柱,第3组试件是在第2组试件的基础上,在翼缘与腹板转角处利用角钢对CFRP布进行锚固。通过对3组钢筋混凝土试件进行轴心受压试验,得到了试件极限荷载、轴向变形以及破坏形态等试验数据。采用有限元软件ABAQUS建立了一批CFRP布约束状态下的混凝土短柱,并对其力学性能进行了分析。根据试验数据及有限元分析结果,提出了CFRP条带约束状态下方形截面钢筋混凝土柱和角钢锚固CFRP条带约束状态下T形截面钢筋混凝土柱极限承载力的计算公式。结果表明：随着CFRP条带用量的增加,加固混凝土柱的承载力增大;当CFRP条带的用量相同时,极限承载力随条带净间距的减小而增大;使用角钢在T形截面柱的翼缘与腹板转角位置对CFRP条带锚固,可以更好地发挥出CFRP条带的抗拉强度,使混凝土柱的极限承载力有所提升。     

Electro-photocatalytic degradation of acid orange II using a novel TiO2/ACF photoanode

A novel photoanode was prepared by immobilizing TiO₂ film onto activated carbon fibers (TiO₂/ACF) using liquid phase deposition (LPD) to study the electro-photocatalytic (EPC) degradation of organic compounds exemplified by an azo-dye, namely, Acid Orange II (AOII). Results demonstrated that by applying a 0.5 V bias (vs. SCE) across the TiO₂/ACF electrode, the AOII degradation rate was increased significantly compared to that of photocatalytic (PC) oxidation. The application of an electric field promotes the separation of photogenerated electrons and holes as confirmed by electrochemical impedance spectroscopy (EIS) measurements. The structural and surface morphology of the TiO₂/ACF electrode was characterized by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). SEM images showed that TiO₂ was deposited on almost every carbon fiber with an average thickness of about 200 nm with the inner space between neighboring fibers being maintained unfilled. The morphological features of the photo-anode facilitated the passage of solution as well as UV light through the felt-form electrode and created a three-dimensional environment favorable to EPC oxidation. Both the large outer surface area of the 3D electrode and the good organic adsorption capacity of the ACF support promoted high contact efficiency between AOII and TiO₂ surface. Anatase was the major crystalline TiO₂ deposited. UV-vis spectrophotometry, TOC (total organic carbon) analysis, and HPLC technique were used to monitor the concentration change of AOII and intermediates as to gain insight into the EPC degradation of AOII using the TiO₂/ACF electrode.     

基于CPU并行计算的概率地震需求#br# 分析与地震易损性分析

概率地震需求分析体现了不确定性从地震动强度参数到工程需求参数的传递过程,文中介绍并对比概率地震需求分析中云图法、单条带法与多条带法的优缺点。以MATLAB+OpenSEES实时交互方式,提出基于CPU并行计算架构的概率地震需求分析方法,显著提高分析效率。提出并行-云图法、并行-单条带法与并行 多条带法,通过RC框剪结构的概率地震需求分析,开展不同层高RC框剪结构的地震易损性分析。研究表明：云图法的对数标准差普遍大于单条带法与多条带法,过高地估计了结构的抗震性能,而单条带法与多条带法在易损性中位值与对数标准差确定方法上存在差异,单条带法的对数标准差普遍低于多条带法。