腐殖质对二氧化锰引起的五氯酚转化反应的影响

研究了在二氧化锰催化引起的五氯酚的转化反应中,腐殖质前身化合物的加入对五氯酚去除率的影响,并以p-coumaricacid为代表研究了体系pH值、反应时间、二氧化锰的质量浓度以及腐殖质前生物的浓度和分子结构对去除率的影响。结果表明,反应的最佳pH值范围是4～4.70,去除率在80%左右。五氯酚在24h内去除速率较快,去除率达到75%左右;反应到168h,去除速率趋于0,去除率达到80%左右。相同条件下,无p-coumaricacid的对照体系中,对应的反应时间内去除率仅分别为20%和25%左右。五氯酚的去除率还随二氧化锰质量浓度和p-coumaricacid浓度的增加而增大。当二氧化锰的质量浓度由0增加到100g·L-1时,去除率由0增大为95%;而当p-coumaricacid的浓度由0增加到1mmol·L-1时,去除率由25%增大到100%左右。此外,不同腐殖质前身物的分子结构和浓度对去除率分别起到了提高、不明显改变和降低的作用。     

介孔纳米TiO2的超声化学法合成及其表征

采用超声化学法制备介孔TiO2，并采用XRD，TEM，FT-IR等方法对样品进行了表征．结果表明，在超声波作用下，液相体系中能够一步合成锐钛矿相TiO2；添加有机模板剂并控制实验条件，则能直接合成具有介孔结构的锐钛矿相TiO2．超声化学法能更好地控制粒子的形貌和尺寸，所制备的TiO2晶型完整，孔径均匀，分散性好．     

Photocatalytic removal of nitrogen oxides via titanium dioxide

We studied the removal of nitrogen oxides pollutants via TiO₂ Degussa P25 powder by photocatalysis. Parameters such as mass of catalyst, geometric irradiated surface, catalyst morphology, and thermal treatment were tested to explain the photocatalytic concentration decrease of nitrogen oxides. According to our working conditions, the conversion rates increased until an optimal value of the TiO₂ weight, 35% of NO concentration and around 20% of NOx, was decomposed by the photocatalysis. The NOx removal increased proportionally with the irradiated geometric surface. The structural transformation of anatase to rutile performed by thermal treatment involved the decrease of the photocatalytic activity.     

SO2长期吸入对大鼠肺组织基因表达谱的影响

采用Affymetrix的基因芯片(RAE230A)技术,研究了SO2长期动态吸入(14mg/m3,1h/d,共30d)后大鼠肺组织基因表达谱的改变.结果表明,与对照组(CK)相比,SO2长期吸入后大鼠肺组织表达上调的基因有173个,其中包括79个已知基因和94个新基因,而表达下调的基因有85个,其中包括46个已知基因和39个新基因.表明:(1)长期吸入SO2的大鼠肺基因表达谱与其CK相比,表达有差异的基因涉及到脂肪酸代谢、免疫、炎症、氧化应激、原癌基因、肿瘤抑制基因和细胞外基质等,表明低剂量长期吸入SO2在体内的机理非常复杂;(2)SO2高剂量短期吸入与低剂量长期吸入后,大鼠肺组织基因表达谱的改变很不一致,表明二者在体内的作用机理不同;(3)SO2可引起多种基因的表达发生改变,这意味着多种基因的表达是易变的、不稳定的,在肺组织中可能存在着SO2诱发的表达不稳定型基因组.表1参19     

二氧化硫与1—己烯的光化学反应动力学

利用ＧＣ／ＭＳ方法研究了ＳＯ２与１－己烯在无氧和有氧体系中光化学反应动力学，确定了ＳＯ２与１－己烯光化学反应的级数，给出了２９３－３３３Ｋ温度范围内总的反应速度常数Ｋ，以及Ｋ与温度的关系、反应的活化能和指前因子。另外，对反应物己醛和２－己酮的生成反应速度常数及其活化能也进行了计算和讨论。     

An Operationally Defined Method to Determine the Speciation of Mercury

This paper presents a modified method of an operationally determined speciation of mercury in soil. The analytical work was mainly concerned to suit properly with inductively coupled plasma-atomic emission spectrometry (ICP-AES). Soil samples analysed in this study were selected from open areas around a crematorium, a waste incinerator, and two power plants. Results show that both topsoil and subsoil samples were dominated by elemental mercury Hg(0) and mercuric sulphide (HgS). The significant correlation between sulphur concentration and HgS was found in topsoil samples.     

TiO2光催化剂的超临界CO2萃取法制备及其降解甲基橙的活性

用超临界二氧化碳萃取TiO2醇凝胶制备纳米二氧化钛粉体，对萃取工艺条件进行了讨论，并用XRD，FT-IR，BET和DRS对上述粉体进行表征．以光催化降解甲基橙为模型反应，结果表明，与超临界二氧化碳干燥所得的粒子比较，该工艺干燥的TiO2粉体粒径小，比表面积大，光催化活性较高。     

Ancillary benefits of reduced air pollution in the US from moderate greenhouse gas mitigation policies in the electricity sector

Actions to slow atmospheric accumulation of greenhouse gases also would reduce conventional air pollutants yielding “ancillary” benefits that tend to accrue locally and in the near-term. Using a detailed electricity model linked to an integrated assessment framework to value changes in human health, we find a tax of $25 per metric ton of carbon emissions would yield NO_x-related health benefits of about $8 per metric ton of carbon reduced in the year 2010 (1997 dollars). Additional savings of $4–$7 accrue from reduced investment in NO_x and SO₂ abatement in order to comply with emission caps. Total ancillary benefits of a $25 carbon tax are $12–$14, which appear to justify the costs of a $25 tax, although marginal benefits are less than marginal costs. At a tax of $75, greater total benefits are achieved but the value per ton of carbon reductions remains roughly constant at about $12.     

中国能源消费导致的CO2排放量的差异特征分析

运用一种不产生残差的方法——对数平均迪氏指数法LMDI(logarithmicmeanDivisiaindex),对中国部分省份、区域能源消费导致的二氧化碳排放量进行了分解分析。将二氧化碳排放总量的变化分解成五个主要影响因素,即化石燃料的排放系数、能源消费结构、能源强度、人均GDP和人口总数。研究表明我国各省(地区)的二氧化碳排放量在1996年后呈现零(或负)增长趋势,主要影响因素是能源强度的提高;各省(地区)的二氧化碳排放量地区差异显著。因此,要在全国实现二氧化碳排放量的总体减排,应从提高能源利用效率,调整产业结构,消除地区发展的不平衡,逐步改善能源消费结构等方面考虑。     

Toxicity of octameric elemental sulphur in aquatic sediments

The proportions of elemental sulphur species in sediment from a contaminated area and a reference sediment sample were compared with the acute toxicity measured in short-term toxicity tests. Octameric elemental sulphur was separated into three operationally defined fractions. Here we show that octameric elemental sulphur contributes to the acute toxicity measured by bioluminescence inhibition. Our findings show that only a small part of extractable elemental sulphur was effective during exposure to the test organisms. A firmly bound fraction of sulphur was found in a contaminated sediment. This information has to be taken into account while interpreting the acute sediment toxicity.