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311.
Ten nitrated polycyclic aromatic hydrocarbons (nPAHs) and 4 oxygenated polycyclic aromatic hydrocarbons (oPAHs) in fine particulate matter (PM2.5) samples from Mount Tai were analyzed during summer (June to August), 2015. During the observation campaign, the mean concentration of total nPAHs and oPAHs was 31.62 pg/m3 and 0.15 ng/m3, respectively. Two of the monitored compounds, namely 9-nitro-anthracene (9N-ANT) (6.86 pg/m3) and 9-fluorenone (9FO) (0.05 ng/m3) were the predominant compounds of nPAHs and oPAHs, respectively. The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization (PMF) method and the potential source contribution function (PSCF) methods. The results revealed that biomass/coal burning, gasoline vehicle emission, diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs, which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea. The incremental life cancer risk (ILCR) values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people (infant, children and adult), and the values of ILCR were 7.02 × 10?10, 3.49 × 10?9 and 1.41 × 10?8 for infant, children and adults, respectively. All these values were lower than the standard of EPA (Environmental Protection Agency) (<10?6), indicating acceptable health risk of nPAHs and oPAHs.  相似文献   
312.
为评价炼化装置中各控制回路的性能,基于控制回路关键品质指标要求,采用控制回路的设定值、输出值、测量值、控制模式等过程参数设计了准确性指标、稳定性指标及快速性指标等性能评估指标。辅助技术人员在线进行控制回路性能评估,识别性能较差的控制回路,诊断异常原因并进行优化,提高装置的自动化水平。  相似文献   
313.
Volatile organic compounds (VOCs) with high toxicity and carcinogenicity are emitted from kinds of industries, which endanger human health and the environment. Adsorption is a promising method for the treatment of VOCs due to its low cost and high efficiency. In recent years, activated carbons, zeolites, and mesoporous materials are widely used to remove VOCs because of their high specific surface area and abundant porosity. However, the hydrophilic nature and low desorption rate of those materials limit their commercial application. Furthermore, the adsorption capacities of VOCs still need to be improved. Porous organic polymers (POPs) with extremely high porosity, structural diversity, and hydrophobic have been considered as one of the most promising candidates for VOCs adsorption. This review generalized the superiority of POPs for VOCs adsorption compared to other porous materials and summarized the studies of VOCs adsorption on different types of POPs. Moreover, the mechanism of competitive adsorption between water and VOCs on the POPs was discussed. Finally, a concise outlook for utilizing POPs for VOCs adsorption was discussed, noting areas in which further work is needed to develop the next-generation POPs for practical applications.  相似文献   
314.
维生素E在动物细胞内具有抗氧化等重要作用,但在植物体内的功能却鲜为人知.本实验利用CaMV 35S启动子与来源于拟南芥的编码生育酚环化酶(TC)的cDNA(VTE1)构建的嵌合表达载体,以根癌农杆菌介导的叶盘法转化烟草W38.实验结果表明,具有卡那霉素抗性的再生植株经RT-PCR检测,得到了与阳性对照一致的495bp的目标片段;转基因植株的VE含量比对照植株高2倍左右,个别株系高达11倍.实验还发现,在耐盐性实验中转基因植株对盐的抗性明显高于野生型烟草;同时,在不同盐浓度(150、250mmoL/L)胁迫下转基因植株VE含量比未转化植株增加了1.3~1.8倍,首次证明VTE1与植物耐盐性之间的关系.  相似文献   
315.

In this paper, Web of Science (a database) is used to retrieve related literature in the field of heavy metal pollution in desert. CiteSpace is used to make a quantitative and qualitative evaluation on the literature in the field on the basis of a brief analysis on the research status, research focus, and evolution process in the field. Through CiteSpace visual analysis, a comparative analysis is given on related literature in terms of annual number of published papers, author groups, and their countries and regions, journals, publishing institutions, highly cited papers, research focuses, and burst terms, so as to explore the research status and future development trend of the field on a global scale. The results are shown as follows: (1) The literature in the field was originally published in 2000; the number of published papers increased steadily. The literature was mostly published on high-quality journals, the USA topped in terms of the number of published papers, and the research results achieved by developed countries had a greater influence. Chinese Acad Sci topped with the highest centrality and most published papers, which have made outstanding contributions to the field and occupy a leading position in the field. However, the fact is that there lacks communication and cooperation among research institutions. The most influential journal is Science of the Total Environment. (2) The hot research words in the field are as follows: heavy metal, soil, pollution, lead, desert, cadmium, and microelement. (3) In the field, burst terms have transformed from atmospheric deposition, biomonitoring, and phytoremediation to trace element, stream sediment, street dust, and water quality, and finally transformed to river and sediment. New words keep emerging in the research, and more and more attention is paid to the issue of heavy metal pollution in river sediment, which will be a future research hotspot in the field.

  相似文献   
316.
Environmental Science and Pollution Research - CdS-AgO@g-C3N4 nanocomposites were successfully synthesized and characterized by XRD, N2 physical adsorption, XPS, SEM, TEM, EDX, and UV–Vis DRS...  相似文献   
317.
Environmental Science and Pollution Research - Atrazine (ATZ), a widely used herbicide, had received a significant amount of attention due to its widespread detection in aquatic environments as...  相似文献   
318.
Environmental Science and Pollution Research - As persistent and ubiquitous contaminants in water, iodinated X-ray contrast media (ICM) pose a non-negligible risk to the environment and human...  相似文献   
319.
Environmental Science and Pollution Research - Energy-related carbon emissions take a large proportion in China, and the interregional trade caused by provincial disparities has led to significant...  相似文献   
320.
江苏沿海地区的相对海平面上升及其灾害性影响研究   总被引:13,自引:0,他引:13  
江苏海岸是全国潮滩最集中分布区,其面积约占全国的1/4,沿海地区地势低平,相对海平面上升幅度较大,是全国少数几个受海平面上升危害最严重的地区之一。初步估算,21世纪前半期该地区不同岸段相对海平面上升速率将可能达到4.5~9.5mm/a,约为同期全球平均上升速率的2~3倍。其灾害性影响主要集中在:①造成堤外潮滩湿地资源损失,相对海平面上升50cm,因直接淹没、侵蚀加剧和淤涨减缓造成的潮滩损失面积将超过5×104hm2,湿地损失面积达2.4×104hm2;②降低海堤防御标准、危及海堤自身和受保护地区安全,相对海平面上升50cm,该地区现有海堤防御标准将由现状50~100年一遇降为20~50年一遇;遇50年一遇风暴高潮位,全区受潮水漫溢的海堤长度将比现状增加173km以上,占海堤总长的1/4;③阻碍低洼地的洪水排泄、加剧洪涝灾害损失,相对海平面上升40cm,苏北里下河和苏南太湖湖东两片洼地的自然排水能力将可能分别下降约25%和20%,若两洼地分别重现1991年型和1954年型洪水,则因海平面上升增加的受淹面积将超过4×104hm2  相似文献   
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