稠环芳烃的致癌性

本文主要介绍了具有角形结构的稠环芳烃的对称性与细胞的形变密切相关，所含的角数和有效稠环数的总和与其致癌性呈线性相关。     

稠环芳烃分子的对称性与其荧光效率的关系

本文主要讨论了几种稠环芳烃分子的对称性与其荧光效率的关系，并认为，在影响稠环芳烃荧光效率的诸多分子结构因素中，分子的对称性是一个不可忽视的重要因素，对称性高的分子，其荧光效率相对较高。     

稠环苯型芳烃分子周期表

介绍了Ｊ．Ｒ．Ｄｉａｓ的多环苯型芳烃周期系的速归原理，在此基础上建立了一个完整的稠环苯型芳烃分子周期表，并讨论了该表的应用．     

HE矩阵和稠环芳烃(PAH)的一种命名法

本文提出了一种新的带有几何因素的邻接矩阵——HE正矩阵,同时不用图心的思想建立了稠环芳烃的一种新的命名法,本方法属p算法(Polynomial algorithm),任何平面稠环芳烃系统均可用此法给出唯一的命名。     

卷烟烟气中多环芳烃的分析方法

通过二次柱层析纯化和富集卷烟烟气中多环芳烃,用气相色谱／质谱法进行多环芳烃的定性和定量分析。在卷烟烟气中检测了蒽、菲、荧蒽,芘,苯并[a]蒽、屈,苯并荧蒽,苯并[e]芘,苯并[a]芘等多环芳烃,其深浓度在8－319nm／支之间,多环芳烃咽收率在80％以上。在此基础上测定了3种不同焦油含量的卷烟 气中的多环芳径,发现卷烟烟气中多环芳烃含量与焦油含量有良好的相关性。     

环境中的多环芳烃与致癌性

多环芳烃属于最强的致癌物质，研究多环烃的形成机理、致癌性与其结构的关系，及多环芳烃在环境中的存在与分布、有助于人们更好的保护环境。     

小龙潭褐煤稠环芳烃的溶出与分析

在超声辅助下对小龙潭褐煤依次用二硫化碳、苯、甲醇、丙酮和四氢呋喃进行分级萃取,用苯和甲醇对萃取残渣进行变温热溶,利用气相色谱/质谱联用仪对萃取物和热溶物的组成和结构进行表征。结果表明,小龙潭褐煤总的萃取率和热溶率分别为1.50%和13.74%,萃取物中检测到29种2~6环的稠环芳烃,其中4-异丙基-1,6-二甲基萘、菲、荧蒽和芘相对含量较高,苯和甲醇热溶物中检测到的稠环芳烃分别为24种和9种,且主要以萘及其同系物为主。     

硝基多环芳烃定量结构——活性关系研究进展

利用近年来较活跃的定量结构－活性关系，通过对硝基取代多环芳烃定理结构－活性关系研究的总结，阐述了硝基取代后的多环芳烃对生物体毒性的影响以及毒性变化的结构原因，为开展这方面的研究提供了有益的参考。     

土壤中多环芳烃的降解与土壤酸度及微生物的关系

利用碳酸钙调节土壤pH值,研究土壤中多环芳烃(菲、苯并[α]芘)污染物的降解情况.在控温、控光的培养室里进行为期15d的避光培养试验.试验设计5种处理试验,观察到土壤中菲、苯并[α]芘的可提取浓度都有减少,降解率分别为13.3%～52.2%、0.9%～35.3%.不同pH值土壤中,菲、苯并[α]芘的降解机制不同,中性土壤有利于菲的降解,酸性土壤有利于苯并[α]芘的降解.同时,土壤中的微生物生物量碳的大小能够反映菲、苯并[α]芘的降解情况.土壤自身具有减少稠环芳烃含量的自然能力.如果改变环境条件促进微生物的活性,就可以加速土壤中微生物对稠环芳烃的消解.     

燃煤飞灰中碳对多环芳烃吸附作用的研究

分别采集燃用褐煤、烟煤和无烟煤电厂排放的飞灰,研究了飞灰中碳对多环芳烃的吸附作用.研究表明:飞灰中碳含量与多环芳烃吸附量之间具有极强的正相关性;飞灰中多孔碳与空心碳的形态结构有利于多环芳烃的吸附.研究旨在为多环芳烃的污染防治提供必要的依据.     

兰州市大气飘尘中多环芳烃分布及来源判识

用ＧＣ－ＭＳ定量和半定量分析了ＰＡＨ组分,研究了区大气飘尘中检测出１６种母核ＰＡＨ,ＰＡＨ的质量浓度随功能区和季节的变化而不同,冬季ＰＡＨ质量浓度高于夏季;ＰＡＨ污染程度依次为：化工区〉民居区〉交通区〉郊区。根据荧蒽与芘质量浓度比值判别市区内ＰＡＨ主要来源于燃料的不完全燃烧。     

用高级氧化技术去除植物油中的多环芳烃

应用植物油淋洗可去除土壤中高浓度多环芳烃,为进一步去除多环芳烃,采用高级氧化(臭氧氧化、过氧化氢和紫外线联合氧化)对两种含多环芳烃植物油进行处理,并考察了运行参数对多环芳烃去除效果的影响.结果表明臭氧具有氧化植物油中多环芳烃的能力,对蒽和荧蒽的氧化能力强于菲.用紫外线、10%过氧化氢,在pH=3的条件下处理MO植物油,总多环芳烃的去除率最高,为81%;按此条件对含高浓度多环芳烃EO植物油处理8 h,总多环芳烃去除率为76.5%,达到良好效果.     

大气飘尘中硝基多环芳烃（NO2—PAH）的分析方法

研究大气飘尘中硝基多环芳烃（ＮＯ２－ＰＡＨ）的分析方法,在毛细管气相色谱－ＥＣＤ（ＧＣ－ＥＣＤ）上比较了冷柱头进样（Ｏｎ－Ｃｏｌｕｍｎ）和不分流进样（Ｓｐｌｉｔｌｅｓｓ）两种方法对ＮＯ２－ＰＡＨ可能产生热降解的影响．用ＧＣ－ＭＳ化学电离负离子方法在线加入含氟试剂Ｎ（Ｃ４Ｆ９）３,使ＮＯ２－ＰＡＨ衍生化或生成稳态负离子,从而大大提高其分析的灵敏度．     

A kinetic modeling study of pollutant formation in premixed hydrocarbon flames

A kinetic modeling of pollutant formation in hydrocarbon flames is presented through analysis of hierarchical structures. Based on the newly released GRI-Mech 3.0,it was mainly taken from Dean and Bozzelli (DB) and Wang mechanism respectively for the nitrogen chemistry, the formarion and growth of polycyclic aromatic hydrocarbons (PAH). The modeling was improved by considering C4 and Howard‘s PAH chemistry. The mechanism consists of 121 species in 731 reactions. Two premixed flame structures are predicted, and the computed results are compared with the experimental ones. It is shown that the mechanism predicts reasonably well the concentration profiles of major, key intermediate and minor species.     

公路沥青拌砂点工作呼吸带空气颗粒物的GC／MS分析

本文利用弹性石英毛细管色谱柱的气相色谱——质谱联用技术,与文献资料对照,对公路沥青拌砂点工作呼吸带空气颗粒物中有机物进行分离和鉴定,在所鉴定的八十五种化合物中,多环芳烃及其衍生物六十九种,链烃十四种,邻苯二甲酸酯二种,并对污染物的危害性和相关作用作了简单的讨论。     

银川市大气颗粒物中有害成分的污染状况及其分布规律

用ＫＢ－１２０型空气采样泵和ＭＷ级联撞击器采集大气颗粒物，采用原子吸收分光光度计和气相色谱等仪器，分析了银川市不同季节、不同功能区大气颗粒物中粒径小于２．５μｍ至１５μｍ颗粒中的多环芳烃（ＰＡＨ）和１５种重金属元素，结果表明银川市的污染主要由燃煤所致。各功能区大气中的ＰＡＨ和１５种重金属元素浓度均很高，ＢａＰ浓度超标。     

多环芳烃对土壤中小麦发育的生态毒性效应

以高等植物小麦的种子发芽和根伸长的抑制率进行土壤苯并[a]芘生物毒．f生研究．将小麦种子播种于土壤中,置于培养箱中25℃黑暗培养47h,观测在不同土壤类型和苯并[a]芘不同浓度下的种子发芽和根伸长．结果表明,多环芳烃苯并[a]芘污染土壤对小麦的种子发芽和根伸长有抑制作用（与对照比较）,因土壤类型的不同,污染物浓度的不同,抑制作用不同．苯并[a]芘污染土壤中,小麦的根伸长抑制浓度大小顺序为：红壤〉水稻土〉潮土,IC50（50％的根伸长抑制浓度）分别为：1670、1515、1451mg／kg．小麦根伸长抑制率与土壤污染物浓度间的相关性高干种平右莽抑制率与苴的相姜性     

Evidence from reversal of handedness in C. elegans embryos for early cell interactions determining cell fates

Many animals with overall bilateral symmetry also exhibit some left-right asymmetries with generally invariant handedness. Therefore, the left-right embryonic axis must have a consistent polarity, whose origins and subsequent effects on development are not understood. Caenorhabditis elegans exhibits such left-right asymmetries at all developmental stages. The embryonic cell lineage is asymmetric as well: although the animal is generally bilaterally symmetric, many of its contralaterally analogous cells arise from different lineages on the two sides of the embryo. I accomplished reversal of embryonic handedness by micromanipulation at the 6-cell stage, which resulted in mirror-image but otherwise normal development into healthy, fertile animals with all the usual left-right asymmetries reversed. This result demonstrates that in the 6-cell embryo the pair of anterior (AB) blastomeres on the right is equivalent to the pair on the left, and that the extensive differences in fates between lineally homologous derivatives of these cells on the two sides of the animal must be dictated by cell interactions, most of which are likely to occur early in embryogenesis.     

Polarity inverted intracloud discharges and electric charge structure of thunderstorm

The three-dimensional spatial and temporal development of impulsive VHF radiation events during lightning discharges has been analyzed based on the data measured by the lightning mapping array (LMA) system with high space and time resolution. The results indicate that intracloud discharges in the thunderstorm with anormal tripole charge structure occur not only between the upper positive and middle main negative charge region, but also with inverted polarity between the lower positive and middle main negative charge region. The polarity-inverted discharge originates from the middle negative charge and propagates downward to the lower positive region, where then the discharge develops horizontally. The characteristics of the discharge are similar to that of normal intracloud discharge except the polarity opposite. The results further confirmed the existence of the lower positive charge region involved in the lightning discharge. It was also found that the inverted charge structure opposite to the normal polarity ap pears in some storms or at a certain stage of the storm development. In the stor m with a polarity inverted charge structure, a main positive charge region is lo cated at the middle part and a negative charge at the upper part of the storm. T he intracloud discharges occurred between them are of inverted polarity, showing the existence of a polarity inverted charging mechanism in storms and the compl exity of storm charge structure.