多环芳烃

Only 2-4 ring PAHs were detected in gas phase, and phenanthrene was the most abundant with an average of 55.1% in total PAHs.

结果显示，气相中主要是2-4环的多环芳烃，其中菲为主要的化合物，平均占到总多环芳烃的55.1%。

The influence of environmental variables on distribution of PAHs(1) The concentrations of PAHs were higher in warm temperate zone and subtropical zonethan in low temperature zone;(2) The concentration in plain, hilly land and Ya\'an mountainousregion were higher than in other places;(3) The concentration in paddy fields, dry land andforests were higher than in artificial land and grass;(4) There was positive correlation betweenthe concentration of PAHs and TOC. The correlation was more obvious for 4-rings PAHs thanfor 5-, 6-rings PAHs;(5) The concentration of PAHs in acid soils was higher than in alkali andneutral soils;(6) The concentrations in conifer and spinney forest were higher than inbroad-leaved forest.Part two: The temporal and spatial distribution characteristics of POPs at Basin-MountainTransect.

环境因素对多环芳烃分布的影响(1)温带和亚热带地区土壤多环芳烃含量高于低温地区土壤中多环芳烃含量；(2)在平原、匠陵和雅安市附近的山区多环芳烃含量高于其他地区含量：(3)水田、旱地和林地多环芳烃含量高于建筑用地和草地中含量；(4)多环芳烃含量和土壤总有机碳含量成正比，四环多环芳烃与总有机碳的相关性高于其他多环芳烃的相关性；(5)酸性土壤中多环芳烃含量高于碱性和中性土壤中含量；(6)针叶林和灌木林多环芳烃含量高于阔叶林中的含量。

Priority PAHs recommended by USEPA were all detected, and the mass concentrations of individual PAHs was between 1.49 and 87.43ngg^(-1), The PAHs with low molecular weight, such as Nap, Flu, Ace were observed in relatively low mass concentrations. The PAHs with high molecular weight, such as Chrysene, Indeno [1, 2, 3-cd] pyrene, Benzo perylene were relatively abundant and the mass congcentration of BghiP was the highest. The total mass congcentration of 16 PAHs exceeded standard of Holand from 10 to 40 times, and in middle pollution level comparatively with other districts.

美国环保总署推荐优先控制的16种多环芳烃均被检出，多环芳烃单体的质量浓度在1.49~87.43ngg^(-1)扩之间；其中萘、药、苊等低分子量芳烃的质量浓度相对较低；窟、茚并[1， 2， 3-cd]苝、苯并苝等高分子量芳烃的质量浓度相对较高，苯并苝的质量浓度最高。16种多环芳烃的质量总浓度超过荷兰政府规定无污染土壤PAHs值的10~40倍；与国内外其他地区相比较，多环芳烃污染处于中等水平。

Data analysis shows that the total amount of PAHs in the sediments of north Taihu Lake is obviously higher than that at the central and south Taihu Lake, and that there is a little difference between the contents of PAHs of high molecular weight and low molecular weight, while the ratio of PAHs varies in different sections of the lake. Through the statistical analysis of the ratio of fluoranthene to pyrene, it is concluded that PAHs mainly come from oil burning with part of them from coal and wood burning.

分析结果表明，太湖北部的多环芳烃总量明显高于中部和南部，低分子量多环芳烃与高分子量多环芳烃的含量差别不大，但在地域上比例有所变化；根据荧蒽/芘的比值统计，多环芳烃主要来源于石油燃烧，部分为煤和木材的燃烧形成。

The PAHs in sediment core were mainly composed of phenanthrene and fluorene. The concentrations of phenanthrene and fluorene in sediment core were 236.1-417.9 ng/g and 91-130.8 ng/g,respectively. Both of them accounted for 47.2%-58.1% of the ∑PAH16 in sediments.

沉积物中多环芳烃的组成以3环的菲和芴为主，它们的含量分别为236.1～417.9 ng/g和91～130.8 ng/g，二者共占沉积物中多环芳烃总量（∑PAH16）的47.2%～58.1%。

However, research on polycyclic aromatic hydrocarbons in the environmental medium within the industrial area has not been reported yet.

目前国内外对环境中的多环芳烃已开展了较多的研究，但有关工业区环境介质中的多环芳烃研究尚未见报道。

The experimental results show that the distributions of content and toxicity equivalent quantity of PAHs in raw coal are similar to coal gasification but this compositions and contents are different. The rise of coal rank leads to the decrease of the content and TEQ of PAHs in raw coal and the increase of TEQ during coal gasification, while the content of PAHs emission from coal gasification increases first and then decreases with the increase of coal rank. The total PAHs contents generated in coal gasification of some sorts of coals are higher than in raw coal. The types of PAHs formed in coal gasification include undecomposed PAHs in raw coal, pyrosysthensis PAHs, and radical polymerization PAHs at high temperature.

试验结果表明：煤气化前后多环芳烃质量分数和毒性当量质量分数的分布特徵相似，但多环芳烃的组成和质量分数不同；煤化程度增加，原煤多环芳烃质量分数和毒性当量质量分数减小，煤气化多环芳烃质量分数先增后减，毒性当量质量分数与煤化程度呈线性关系；部分煤种气化多环芳烃的质量分数高於原煤多环芳烃质量分数，且煤气化多环芳烃的种类分为原煤未分解的多环芳烃、热解合成的多环芳烃、自由基高温缩合生成的多环芳烃。

Fat drippings create smoke that is filled with carcinogenic polycyclic aromatic hydrocarbons, or PAHs. When the smoke envelopes the food, it transfers the PAHs onto the surface of the meat. And when meat, chicken and fish are grilled at high temperatures for long periods of time, compounds inside the food react and create heterocyclic amines, or HCAs. HCAs are worrisome because in lab studies they've been shown to trigger breast, colon and prostate tumors in rats and mice.

滴下来的油脂产生的烟雾充满了致癌的多环芳烃，简称PAHs，当烟雾环绕在食物周围的时候，这些多环芳烃也附着在了食物的表面，当猪肉，鸡肉或是鱼肉在长时间的高温烧烤时，这些食物本身所含有的成分产生了化学变化生成杂环胺类物质，简称HCAs，这类物质相当的麻烦，因为实验室研究发现它们会引起大鼠和小鼠乳腺，结肠以及前列腺部位的肿瘤。

There are more than 100 different PAHs.Most PAHs do occur alone in the environment.

绝大多数的多环芳烃在环境中不是单独存在，它们往往是两个或更多的多环芳烃的混合物。

Rather they are found as mixtures of two or more PAHs.

绝大多数的多环芳烃在环境中不是单独存在，它们往往是两个或更多的多环芳烃的混合物。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。