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131.
上海世博会供用电系统安全柔性化应急响应机制研究 总被引:1,自引:0,他引:1
分析了上海世博会供用电系统的安全保障现状,提出了世博会供用电系统数量柔性与时间柔性参数的度量方法.从制定上海世博会供用电安全保障应急预案、完善输电系统的安全保障措施、构建供用电系统应对突发性安全事故的应急物流体系及相应的应急管理策略等方面提出了具体的方案. 相似文献
132.
作者把气相色谱仪(GC)与自行研制的光离子化检测器(PID)联用,实现了大气中痕量烃类化合物的直接测定,给出了仪器的构成和性能指标及测量结果. 相似文献
133.
Identification of sources of elevated concentrations of polycyclic aromatic hydrocarbons in an industrial area in Tianjin, China 总被引:2,自引:0,他引:2
Wentao Jiao Yonglong Lu Jing Li Jingyi Han Tieyu Wang Wei Luo Yajuan Shi Guang Wang 《Environmental monitoring and assessment》2009,158(1-4):581-592
The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector in 105 topsoil samples from an industrial area around Bohai Bay, Tianjin in the North of China. Results demonstrated that concentrations of PAHs in 104 soil samples from this area ranged from 68.7 to 5,590 ng g???1 dry weight with a mean of ∑16PAHs 814 ± 813 ng g???1, which suggests that there exists mid to high levels of PAH contamination. The concentration of ∑16PAHs in one soil sample from Tianjin Port was exceptionally high (48,700 ng g???1). Ninety-three of the 105 soil samples were considered to be contaminated with PAHs (>200 ng g???1), and 25 were heavily polluted (>1,000 ng g???1). The sites with high PAHs concentration are mainly distributed around chemical industry parks and near highways. Two low molecular weight PAHs, naphthalene and phenanthrene, were the dominant components in the soil samples, which accounted for 22.1% and 10.7% of the ∑16PAHs concentration, respectively. According to the observed molecular indices, house heating in winter, straw stalk combustion in open areas after harvest, and petroleum input were common sources of PAHs in this area, while factory discharge and vehicle exhaust were the major sources around chemical industrial parks and near highways. Biological processes were probably another main source of low molecular weight PAHs. 相似文献
134.
Spatial and temporal variations and possible sources of dichlorodiphenyltrichloroethane (DDT) and its metabolites in rivers in Tianjin, China 总被引:5,自引:0,他引:5
Water, suspended solid (SS) and sediment samples were collected from nine water courses in Tianjin, China and analyzed for dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDXs, including o,p'-,p,p'-DDT, DDD and DDE). The average DDX concentrations in water, SS and sediment were 59+/-30 ng l(-1), 2690+/-1940 ng g(-1)dry wt. and 340+/-930 ng g(-1)dry wt., respectively. Due to the termination of the extensive agricultural application and industrial manufacture, DDXs in river sediment decreased by one order of magnitude since 1970's and low DDT fractions in these sediments were observed. Still, DDXs in the sediments near the outlets of the major manufacturers remained relatively high attributed to the historic input. DDXs in sediment were also positively correlated with organic matter content. Spatial distributions of DDXs in SS and water was different from that in sediment. For SS, a negative correlation between DDX concentration and SS content indicated a dilution effect in many rivers. Dissolved organic carbon content was the major factor affecting DDX concentrations in water phase. Wastewater discharged from dicofol manufacturers and likely illegal agricultural application were the primary reasons causing high DDT (DDE+DDD) ratios in SS and water. 相似文献
135.
Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age 总被引:1,自引:0,他引:1
Kuang YW Wen da Z Zhou G Liu SZ 《Environmental pollution (Barking, Essex : 1987)》2007,145(3):730-737
Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al. 相似文献
136.
Kuang YW Zhou GY Da Wen Z Liu SZ 《Environmental science and pollution research international》2007,14(4):270-275
Goal, Scope and Background Rapid urbanization and the expansion of industrial activities in the past several decades have led to large increases in emissions
of pollutants in the Pearl River Delta of south China. Recent reports have suggested that industrial emission is a major factor
contributing to the damages in current natural ecosystem in the Delta area. Tree barks have been used successfully to monitor
the levels of atmospheric metal deposition in many areas, but rarely in China. This study aimed at determining whether atmospheric
heavy metal deposition from a Pb-Zn smeltery at Qujiang, Guangdong province, could be accurately reflected both in the inner
bark and the outer bark of Masson pine (Pinus massoniana L.). The impact of the emission from smeltery on the soils beneath the trees and the relationships of the concentrations
between the soils and the barks were also analyzed.
Methods Barks around the bole of Pinus massoniana from a pine forest near a Pb-Zn smeltery at Qujiang and a reference forest at Dinghushan natural reserve were sampled with
a stainless knife at an average height of 1.5 m above the ground. Mosses and lichens on the surface barks were cleaned prior
to sampling. The samples were carefully divided into the inner bark (living part) and the outer bark (dead part) in the laboratory,
and dried and ground, respectively. After being dry-ashed, the powder of the barks was dissolved in HNO3. The solutions were analyzed for iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni) and cobalt
(Co) by inductively coupled plasmas emission spectrometry (ICP, PS-1000AT, USA) and Cadmium (Cd) and lead (Pb) by graphite
furnace atomic absorption spectrometry (GFAAS, ZEENIT 60, Germany). Surface soils (0–10 cm) beneath the sample trees were
also collected and analyzed for the selected metals.
Results and Discussion Concentrations of the selected metals in soils at Qujiang were far above their environmental background values in the area,
except for Fe and Mn, whilst at Dinghushan, they were far below their background values, except for Cd and Co. Levels of the
metals, in particular Pb and Zn, in the soils beneath the sample trees at Qujiang were higher than those at Dinghushan with
statistical significance. The result suggested that the pine forest soils at Qujiang had a great input of heavy metals from
wet and dry atmospheric deposition, with the Pb-Zn smeltery most probably being the source.
Levels of Cu, Fe, Mn, Zn, Ni and Pb at Qujiang, both in the inner and the outer bark, were statistically higher than those
at Dinghushan. Higher concentrations of Pb, Fe, Zn and Cu may come from the stem-flow of elements leached from the canopy,
soil splash on the 1.5 m height and sorption of metals in the mosses and lichens growing on the bark, which were direct or
indirect results from the atmospheric deposition. Levels of heavy metals in the outer barks were associated well with the
metal concentrations in the soil, reflecting the close relationships between the metal atmospheric deposition and their accumulation
in the outer bark of Masson pine. The significant (p<0.01) correlations of Fe-Cu, Fe-Cr, Fe-Pb, Fe-Ni, Pb-Ni, and Pb-Zn in
the outer barks at Qujiang again suggested a common source for the metals. The correlation only occurred between Pb and Ni,
Cd and Co in the outer barks at Dinghushan, which suggested that those metals must possibly have other uncommon sources.
Conclusions Atmospheric deposition of the selected metals was great at Qujiang, based on the levels in the bark of Pinus massoniana and on the concentrations in the soils beneath the trees compared with that at Dinghushan. Bark of Pinus massoniana, especially the outer bark, was an indicator of metal loading at least at the time of sampling.
Recommendations and Perspectives The results from this study and the techniques employed constituted a new contribution to the development of biogeochemical
methods for environmental monitoring particularly in areas with high frequency of pollution in China. The method would be
of value for follow up studies aimed at the assessment of industrial pollution in other areas similar with the Pearl River
Delta. 相似文献
137.
Feng Y Shi G Wu J Wang Y Zhu T Dai S Pei Y 《Journal of the Air & Waste Management Association (1995)》2007,57(2):164-171
Particle-associated polycyclic aromatic hydrocarbon (PAH) concentrations were investigated at six sampling sites in the heating (February to March 2001) and nonheating (August to September 2001) periods in an industrial city in Northern China. Thirteen PAHs were measured. The total average concentrations (nanograms per meter cubed) of PAHs ranged between 78.93 and 214.63 during the heating period and from 31.48 to 102.26 in the nonheating period. Benzo(a)pyrene occurred at the highest level at a site near an industrial area but occurred at low concentrations far from the city center and industrial areas. In addition, ambient PAH profiles were studied. The five and six-ring species occurred in high fractions at the sampling site. By diagnostic ratio analysis, the major source at each sampling site in the city was coal combustion in the heating period; in the nonheating period, the major sources were relatively complex. Finally, the similarities among the six regions were assessed by principal component analysis, cluster analysis, and coefficient of divergence. These multivariate statistical analyses produced similar results, which agreed with the results from the diagnostic ratio analysis. 相似文献
138.
139.
我国典型村庄农村环境质量监测与评价 总被引:2,自引:1,他引:1
选取典型村庄,基于农村环境质量监测和评价方法,对典型村庄2014年农村环境质量进行监测和评价,结果表明:典型村庄环境空气质量状况总体良好,达标比例为82.0%,超标村庄多分布在中国西北地区;农村饮用水源地水质较差,总体水质达标比例为67.1%,地表水和地下水饮用水源地水质达标比例分别为89.8%和52.6%;农村地表水环境质量欠佳,Ⅰ~Ⅲ类水质断面占72.7%,饮用水水源地和地表水水质各地区均存在超标村庄;部分地区土壤重金属超标问题较为突出,出现监测项目超标情况村庄占20.6%,土壤超标村庄主要集中在中国东北、华中和华南等地区;农村生态质量状况相对较好,"较差"和"差"的县域主要分布在中国西北和华中北部地区。 相似文献
140.