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81.
乌鲁木齐市大气硫酸盐化速率与二氧化硫浓度的相关性   总被引:1,自引:0,他引:1  
对全市1989年至1991年中大气硫酸盐化速率与二氧化硫的监测数据进行了相关性研究,结果表明:除七道湾化工厂外,两项目间存在着非常显著的正相关关系.对建成区7个测点三年中83对监测数据进行了一无线性回归分析,建立了合理可行的回归方程式  相似文献   
82.
研究了上海西南郊区PM2.5(细颗粒物)污染特征,分析了PM2.5与其它污染因子和气象因子相关性,并提出了PM2.5污染控制建议。  相似文献   
83.
To identify the critical factors impacting the number concentration of particles with the aerodynamic diameters less than 2.5 μm(PNC_(2.5)), the continuous measurement of PNC_(2.5),chemical components in PM_(2.5), gaseous pollutants and meteorological conditions were conducted at an urban site in Tianjin in June 2015. Results indicated that the average PNC_(2.5) was 2839 ± 2430 d N/dlog Dp 1/cm~3 during the campaign. Compared to other meteorological parameters, the relative humidity(RH) had the strongest relationship with PNC_(2.5), with a Pearson's correlation coefficient of 0.53, and RH larger than 30% influenced strongly PNC_(2.5).The important influence of secondary reactions on PNC_(2.5) was inferred due to higher correlation coefficients between PNC_(2.5) and SO_4~(2-), NO_3~-, NH_4~+(r = 0.78–0.89; p 0.01) and between PNC_(2.5) and ratios that represent the conversion of nitrogen and sulfur oxides to particulate matter(r = 0.42–0.49; p 0.01). Under specific RH conditions, there were even stronger correlations between PNC_(2.5) and NO_3~-, SO_4~(2-), NH_4~+, while those between PNC_(2.5) and EC, OC were relatively weak, especially when RH exceeded 50%. Principal component analysis(PCA) and Pearson's correlation analysis indicated that secondary sources, vehicle emission and coal combustion might be major contributors to PNC_(2.5). Backward trajectory and potential source contribution function(PSCF) analysis suggested that the transport of air masses originated from these regions around Tianjin(Liaoning, Hebei, Shandong and Jiangsu) influenced critically PNC_(2.5). The north of Jiangsu, the west of Shandong, and the east of Hebei were distinguished as major potential source-areas of PNC_(2.5) by PSCF model.  相似文献   
84.
Chemical exposure can indirectly affect leaf microbiota communities, but the mechanism driving this phenomenon remains largely unknown. Results revealed that the co-exposure of glyphosate and multi-carbon nanotubes (CNTs) caused a synergistic inhibitory effect on the growth and metabolism of Arabidopsis thaliana shoots. However, only a slight inhibitory effect was induced by nanotubes or glyphosate alone at the tested concentrations. Several intermediate metabolites of nitrogen metabolism and fatty acid synthesis pathways were upregulated under the combined treatment, which increased the amount of energy required to alleviate the disruption caused by the combined treatment. Additionally, compared with the two individual treatments, the glyphosate/nanotube combination treatment induced greater fluctuations in the phyllosphere bacterial community members with low abundance (relative abundance (RA) <1%) at both the family and genus levels, and among these bacteria some plant growth promotion and nutrient supplement related bacteria were markable increased. Strikingly, strong correlations between phyllosphere bacterial diversity and metabolites suggested a potential role of leaf metabolism, particularly nitrogen and carbohydrate metabolism, in restricting the range of leaf microbial taxa. These correlations between phyllosphere bacterial diversity and leaf metabolism will improve our understanding of plant-microbe interactions and the extent of their drivers of variation and the underlying causes of variability in bacterial community composition.  相似文献   
85.
对已报道的农药正辛醇/水分配系数的6种测定方法进行了简述和比较,对农药Kow值与其他环境参数Sw,Koc,BCF1的相关性进行了综述。  相似文献   
86.
本文于对黑龙江省五大连池六个采样点2010年不同季节的水样进行分析,用稀释平板法测定细菌总数,碘量法测定DO值,然后时细菌、DO值及pH值的季节变化和它们之间的相互关系进行初步研究。  相似文献   
87.
灰色关联分析法在土壤重金属污染评价中的应用   总被引:1,自引:0,他引:1  
以陕西凤县寺沟铅锌矿区土壤重金属污染评价为例,介绍了灰色关联分析法在土壤重金属污染评价中的应用,结果表明基于灰色关联分析的土壤重金属污染评价方法能够较完整地反映土壤重金属污染程度,是一种实用且准确的评价方法.  相似文献   
88.
乌鲁木齐市大气环境质量变化趋势分析   总被引:1,自引:0,他引:1  
以乌鲁木齐市2004~2010年间的大气环境质量监测数据为依据,采用空气污染综合指数法评价其大气环境质量,并运用Spearman秩相关系数预测其发展趋势.结果表明:乌鲁木齐市大气环境质量为轻度污染,主要污染物为SO2和PM10.NO2和PM10有上升趋势,SO2呈不显著下降趋势.  相似文献   
89.
Methanol is the most widely used natural gas hydrate inhibitor and it is only effective as a hydrate inhibitor in the aqueous phase. Methanol is not regenerated in natural gas inhibition process due to its intermittent application in most cases. However, a significant cost is associated with the process because of methanol loss while utilizing this inhibitor. In this work, several intelligent models along with a new mathematical correlation are presented in terms of methanol concentration in aqueous phase and temperature to precisely forecast the methanol loss in the saturated hydrocarbons phase. An excellent match was noticed between the calculated results and literature data.  相似文献   
90.
西安城区大气PM_(2.5)中有机碳与元素碳的污染特征   总被引:1,自引:1,他引:0  
为研究西安市夏、秋、冬3季大气细颗粒物中碳组分的污染变化规律,于2013年夏、秋、冬3季在西安市明城墙内采集大气中的PM2.5样品,测定了样品中的有机碳和元素碳的含量。结果显示,PM2.5中OC和EC的季节平均浓度冬季最高,秋季次之,夏季最低。OC/EC的比值在夏、秋、冬3季均超过2.0,说明采样期间夏、秋、冬3季均存在二次污染。OC/PM2.5的比值夏秋两季差异较小,冬季明显高于夏秋两季;EC/PM2.5的比值在夏、秋、冬3季的变化不大。OC和EC的相关性:夏季秋季冬季。OC与PM2.5的相关程度冬季秋季夏季,且随季节更替变化明显;EC与PM2.5的相关性:秋季夏季冬季。即随着季节变化PM2.5浓度水平整体升高、污染加重时,PM2.5中的OC所占比例明显升高,EC比较稳定,说明受人为影响的二次排放为主要成分的OC对PM2.5贡献更大。  相似文献   
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