Structural effect on photocatalytic degradation of metallised azo dyes in aqueous TiO2 suspension

Three metallised azo dyes were investigated under TiO₂‐photocatalytic and photosensitised conditions in aqueous buffering solutions. The degradation follows apparent first‐order kinetics. The size and strength of intramolecular conjugation determine the light‐fastness of the investigated dyes. Compared with ¹O₂ produced in photosensitised process, the more powerful *OH radicals in TiCO₂ photocatalytic process are highly reactive towards the investigated azo dyes. And as a result, the TiO₂‐photocatalysis makes little less distinction in the degradation kinetic data of the azo dyes compared with the photosensitised degradation of them.     

市政污泥脱水性能实验研究与形态学分析

本研究将运用微波技术与离心脱水相结合的方法来达到促进污泥中结合水释放及改善脱水特性的目的.通过测定毛细吸水时间、黏度、含水率,采集污泥图像、提取形态学特征进行污泥脱水改性的效果分析及分形维数的分析.离心脱水实验结果表明,适当增加离心转速和温度时,污泥的含水率降低;正交实验结果表明微波功率1000W、微波温度50℃、离心转速2000r/min、离心时间15min的条件下含水率最低达到83.75%,且适当的微波预处理条件有利于污泥的脱水;微波预处理后污泥分形维数在2.4~2.8之间,污泥结构改变.对污泥脱水性能的表征参数与污泥含水率进行拟合,建立污泥脱水性能的模型,为预测和改善污泥脱水性能提供基础性研究.     

基于突变级数法的企业应急动态能力评价研究

针对企业开展应急能力评价不够科学、合理的问题,在相关理论研究基础上,提出1种将突变级数方法和动态能力理论相结合的企业应急能力评价方法。基于突变级数方法,构建企业应急能力的突变评价模型;采用动态能力理论,从感知、整合、重构和学习4个方面建立企业应急动态能力评价指标体系,给出具体评价步骤;改进评价方法并进行实例分析。研究结果表明:该方法对评价企业应急动态能力具有一定的参考价值。     

试论我国城市应急软能力提升路径——基于2016年武汉洪涝灾害的理性思考

城市应急能力建设是保障城市公共安全的关键环节。当前我国城市应急能力建设重“硬件”轻“软件”,导致在城市灾害应对过程中效果不佳。选取受2016年南方洪涝影响严重的武汉市作为研究对象,对城市内涝灾害治理过程中应急“软能力”的现状及功能进行剖析,提出在制度适应、风险管理以及理念协调等方面的重构思想,并论述城市应急“软能力”的提升路径:建立健全防灾导向的城市规划制度,推进协同导向的城市灾害风险管理,加强完善教育导向的城市灾害文化建设。     

光催化技术降解水中环境药物的研究进展

环境水体中检测到大量药物的存在,主要包括抗生素,抗惊厥抗抑郁药物,解热和非甾体消炎药,血脂调整剂,β-阻滞剂等。传统的水处理技术并不能有效地去除这些药物,存在于水体中的环境药物对公共健康的潜在危害引起了广泛的关注。文中简要地介绍了近年来光催化技术在降解环境药物动力学和机理方面的研究进展,试图找出水体中环境药物降解的一般规律,为环境水体中该类物质的迁移和转化提供理论依据。     

Effects of carrying handles,postures, materials and distances on carrying capability

This study recruited 14 industrial workers to examine the effects of carrying handles, postures, materials and distances on maximum acceptable weights of carrying (MAWC), and resulting heart rate and body rating of perceived exertion (RPE) for a 20 min intensive carrying task. This study showed that MAWC of carrying with bar handles, carrying with hands-and-body posture, solid materials and 4?m distance were significantly higher than that of carrying with groove handles, carrying with hands posture, liquid materials and 8?m distance, respectively. The resulting heart rates while carrying MAWCs of groove handles, hands-and-body carrying posture, solid materials and 4?m distance were lower than the resulting heart rates while carrying MAWCs of bar handles, hands carrying posture, liquid materials and 8?m distance, respectively. Most pair levels of independent variables resulted in similar body's RPEs except for the pair levels of carrying distance.     

La掺杂TiO2/有机改性膨润土对TNT弹药废水的光催化降解性能研究

利用超声强化溶胶-凝胶法制备了La掺杂TiO2/有机改性膨润土复合光催化材料并进行了结构表征;以弹药废水中主要污染物质TNT作为目标物,考察了影响光催化降解性能的因素.结果表明：有机改性后复合材料的吸附性能和光催化性能均有所增加,对TNT的60min的吸附去除率和光催化降解率分别达到9.68％和94.53％;影响TNT光催化降解率的因素有光照时间、催化剂用量、TNT初始浓度、溶液pH值和光照强度.     

基于云模型的城轨信号系统安全保障能力评价方法*

为准确评价城轨信号系统安全保障能力及影响因素,基于云理论对定性与定量因素的良好融合优点,构建城轨信号系统安全保障能力评价云模型及评价指标体系,采用组合赋权法对各指标赋予权重,并基于专家意见,利用正向云发生器生成标准云。结果表明:该云模型具有一定稳定性和可靠性,可对城轨信号系统安全保障能力进行有效测评,同时能够发现安全运营中的缺陷,有助于协助管理方进行针对性改善,以提高城轨信号系统的安全保障能力。     

几种阴阳离子对磷钨酸光催化降解甲基橙的影响

以磷钨酸为光催化剂,在紫外灯照射下,对甲基橙溶液进行光催化降解,考察了几种阴阳离子对磷钨酸光催化降解甲基橙溶液的影响。结果表明：Mg^2＋、Ca^2＋、NO3^-、SO4^2-和CO3^2-均对催化活性有促进作用,其中Mg^2＋和Ca^2＋仅有微弱的促进作用;NO3^-和SO4^2-随着浓度的增加促进作用也有所增加;CO3^2-则随着浓度的增加促进作用呈下降趋势;Mn^2＋、Al^3＋和Cl^-对光解反应存在较强的抑制作用,且Al^3＋和Cl^-随着其浓度的增加,抑制作用增强。     

Influence of environmental temperature and relative humidity on photocatalytic oxidation of toluene on activated carbon fibers coated TiO2

TiO₂ supported on active carbon fiber (TiO₂/ACF), an absorbable photocatalyst, is a new kind of material applied in air purification. In this paper, the influence of environmental temperature (T) and relative humidity (RH) on the gas-solid adsorption of toluene and the photocatalytic oxidation (PCO) efficiency of adsorbed toluene on TiO₂/ACF were studied, and then, the purification capability of TiO₂/ACF was estimated. PCO results showed that although the PCO efficiency increased under high RH and T levels, the amount of adsorption of toluene decreased. Moreover, quantitative analysis results of intermediates indicated that more environmental risk emerged when PCO of toluene was carried out at higher environmental T and RH levels because more toxic intermediates would be accumulated on the TiO₂/ACF. So, it is significant to control the environmental T and RH conditions in the application of the PCO technique. T = 25°C and RH530% is the optimal condition for purifying toluene in our experimental system. __________ Translated from Urban Environment & Urban Ecology, 2007, 20(5): 10–13 [译自: 城市环境与城市生态]