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金厂沟梁金矿床的矿脉走向主要为NW向和近SN向 ,NW向矿脉中矿体赋存深度比近SN向矿脉浅约 2 0 0m。近南北向矿脉的金矿体主要赋存在矿脉向西凸出与平稳变化的转折部位。As、Sb含量和F3因子得分值的高值指示矿体上部 ,Co、Mo含量和F5因子得分值的高值指示矿体的下部或尾部。黄铁矿是最主要的载金矿物 ,中粒、半自形晶 ,碎裂发育 ,晶体内含杂质较多的黄铁矿含金率高。在东矿区 ,近SN向矿脉的探矿重点应放在寻找六中段以上部位的平行矿脉 ,NW向矿脉的探矿重点应放在二—三中段以上的较浅部位 相似文献
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Zheng Hua Piao Jongkeun Lee Jae Young Kim 《Journal of Material Cycles and Waste Management》2018,20(1):147-154
Even though full-scale digesters have been designed based on laboratory-scale tests, the substrate feeding modes of laboratory-scale tests might be different from those of full-scale digesters. The effect of substrate feeding frequencies on the performance and microbial community of laboratory-scale anaerobic digestion reactors was investigated. Feeding frequencies of twice a day, once a day, and every two days were tested in three 2-L reactors with an organic loading rate of 0.5 g-glucose/L/day under mesophilic condition. According to the results of this study, all the reactors showed similar methane production rates and SCOD removal efficiencies after sufficient time of acclimation, but frequently feeding promoted more stable digestion. Although there was no significant difference in microbial diversities from pyrosequencing analyses, the changes of archaeal community composition were observed. The decrease in feeding frequency appeared to cause shifts from acetoclastic methanogens affiliated with Methanosaeta to H2-utilizing methanogens. The increase of Methanosaeta at a frequently feeding might contribute to the stability of reactor operation. Since this study uses glucose as the substrate, there is still possibility of different results for more complex substrates, such as sludge, food waste, etc. 相似文献
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为了控制污水脱氮中N2O排放,在不同曝气强度下研究了好氧硝化段同时硝化反硝化(SND)系统的N2O排放特性,并采用PCR—DGGE技术分析微生物群落特征。结果发现,随着曝气强度的增强,系统总氮去除率下降,但脱氮中N2O—N所占比例则上升,实验中从低到高3个曝气强度下,总氮去除率分别为80.01%、65.28%和58.62%,脱氮中N2O—N所占的比例为1.89%、7.84%和9.20%。PCR—DGGE分析显示,和低曝气强度下相比中、高曝气强度下系统微生物群落发生明显变化,但中曝气强度和高曝气强度下系统微生物群落表现出较高相似性。这表明,不同曝气强度下系统N2O排放受到氮素转化和微生物群落变化的影响。适宜曝气强度不仅提高总氮去除率,还可有效控制N2O排放。 相似文献
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朴光洙 《中国环境管理干部学院学报》2011,(5):10-12,16
企业环境监督员资质管理制度是推动企业履行环境责任的重要手段,是建立和完善现代企业环境管理制度的重要环节,是提高环境执法有效性的重要保障。同时建立企业环境监督员资质管理制度将促进我国环境专业人才的培养与发展。因此,应将其纳入法制管理轨道,充分发挥其作用。 相似文献
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Wei S Liu M Huang B Bi X Sheng G Fu J 《Journal of environmental monitoring : JEM》2011,13(9):2568-2574
Daytime and nighttime PM(2.5) samples were collected between August 5 and 16, 2009 and between January 24 and February 4, 2010 in an industrial complex site (site A) and an electronic waste recycling site (site B) to determine the seasonal and diurnal variations of 19 individual polycyclic aromatic hydrocarbons (PAHs) with molecular weight 302 (MW302) including four highly carcinogenic dibenzopyrene (DBP) isomers dibenzo[a,l]pyrene (DBalP), dibenzo[a,e]pyrene (DBaeP), dibenzo[a,i]pyrene (DBaiP), and dibenzo[a,h]pyrene (DBahP). This is the first report on DBP isomers in air particles from South China. The total concentration of PAH MW302 isomers ranged from 1.65 to 3.60 ng m(-3) in summer and 3.82 to 9.81 ng m(-3) in winter. The strongest peaks in the chromatograms of the MW302 isomers were naphtha[2,1-a]pyrene (N21aP), dibenzo[j,l]fluoranthene (DBjlF), naphtha[1,2-b]fluoranthene (N12bF), naphtha[1,2-k]fluoranthene (N12kF) and dibenzo[a,e]fluoranthene (DBaeF), constituting 52.0 to 55.4% of the total MW302 isomers. All the MW302 isomers showed notable seasonal variations. Most of the MW302 isomers in site B showed distinctive diurnal variations with higher concentrations occurring in the night. Taking into account both concentration and potency equivalence factors (PEFs), the strongest carcinogen in the analyzed samples was DBaiP, and the ratios of sum carcinogenic potency of four highly carcinogenic DBP isomers to benzo[a]pyrene (BaP) was about 0.94 in winter to 1.89 in summer, indicating the importance of DBP isomers for the risk assessment. Health risk assessment indicated that on average, 1 in 100 000 residents in the two industrial sites may have an increased risk of cancer due to PAH exposure. 相似文献
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Jingwen Zeng Piao Xu Guiqiu Chen Guangming Zeng Anwei Chen Liang Hu Zhenzhen Huang Kai He Zhi Guo Weiwei Liu Jing Wu Jiangbo Shi 《环境科学学报(英文版)》2019,31(1):181-192
Due to the wide use of silver nanoparticles (AgNPs) in various fields, it is crucial to explore the potential negative impacts on the aquatic environment of AgNPs entering into the environment in different ways. In this study, comparative experiments were conducted to investigate the toxicological impacts of polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) with two kinds of dosing regimens, continuous and one-time pulsed dosing, in different exposure media (deionized water and XiangJiang River water). There were a number of quite different experimental results (including 100% mortality of zebrafish, decline in the activity of enzymes, and lowest number and length of adventitious roots) in the one-time pulsed dosing regimen at high PVP-AgNP concentration exposure (HOE) compared to the three other treatments. Meanwhile, we determined that the concentration of leached silver ions from PVP-AgNPs was too low to play a role in zebrafish death. Those results showed that HOE led to a range of dramatic ecosystem impacts which were more destructive than those of other treatments. Moreover, compared with the continuous dosing regimen, despite the fact that higher toxicity was observed for HOE, there was little difference in the removal of total silver from the aquatic environment for the different dosing regimens. No obvious differences in ecological impacts were observed between different water columns under low concentration exposure. Overall, this work highlighted the fact that the toxicity of AgNPs was impacted by different dosing regimens in different exposure media, which may be helpful for assessments of ecological impacts on aquatic environments. 相似文献