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381.
废弃酸碱精制实现变压器油清洁生产 总被引:1,自引:0,他引:1
利用糠醛精制代替酸碱精制实现变压器油清洁生产,每年减少废渣排放5454t,减少加工损失5454t,取得了良好的环保效益和经济效益。 相似文献
382.
滥木厂铊 (汞 )矿床产于NE向滥木厂鼻状背斜核部和近核部 ,并严格受控于与背斜关系密切的NE向断裂组。矿床中矿体的产出则多与层间虚脱空间有关 ,且主要产于晚二叠世龙潭组 (P2 l)和长兴组 -大隆组 (P2 c+d)。对该矿床不同部位取样并进行构造地球化学模拟实验 ,其结果表明 :成矿元素的活化和迁移与塑性变形关系密切 ,脆性变形和塑性变形的层间滑移则为矿体形成提供了有利空间 ;在应力作用下 ,导致有机质的局部富集 ,为富铊矿体的形成提供了条件。实验结果与汞铊矿体和富铊矿体主要产于晚二叠世含煤岩系有利岩石组合内的情况一致 相似文献
383.
石油污染对非洲鲫鱼血清蛋白的影响 总被引:11,自引:0,他引:11
本文通过分析非洲鲫鱼清蛋白含量的变化,研究油对鱼类的致毒效应,试验结果表明,对血清蛋白影响的方式为:(1)油既能提高血清总蛋白和球蛋白含量,又能降低血清白蛋白含量和白蛋白/球蛋白的比值;(2)油对非洲鲫鱼血清蛋白产生作用的浓度阈值为0.05mg/L。 相似文献
384.
黄河中游水保措施对入黄干支流泥沙特性的影响:Ⅰ. 泥沙粒径变化 总被引:5,自引:1,他引:5
过去关于水土保持措施影响的研究多侧重于减水减沙的影响,对泥沙组成影响的研究则相对较少。本文以大量的实测资料为依据,以河口至龙门间区域自然与水土保持条件为背景,将水保措施类型、河道水流泥沙条件与流域地貌条件结合考虑,借助统计分析方法对采用水保措施前后该区域(尤其是与黄河中游水土流失密切相关的黄土高原与沙砾丘陵区域)的泥沙粒径分布变化进行了探讨。分析表明,泥沙粒径分布变化极其复杂,对应于不同地貌类型条件的泥沙组成遵循不同的分布规律。黄土丘陵区河流中的悬移质泥沙级配服从正态分布规律,而沙砾丘陵区河流中的泥沙级配则服从皮Ⅲ型分布规律。当分布函数的类型确定后,泥沙粒径分布由该分布函数的几个参数共同决定,这些参数分别反映了泥沙从流域表层搬运到对应级别河流的过程中地貌形态及水土保持措施的影响。文中由多学科综合研究得到的结论,对黄河中游水土保持效益研究具有重要意义。 相似文献
385.
岛群围填海过程中岸线与植被变化特征初步探究——以舟山石化基地为例 总被引:1,自引:0,他引:1
通过遥感(RS)结合地理信息系统(GIS)的方法,解译舟山石化基地工程所在区域7个时期卫星遥感影像。结合收集相关资料和登岛实地调查,提取并分析了舟山石化基地建设不同时期岸线变迁和植被分布变化情况。研究结果表明:近3 a内,舟山石化基地工程所涉及岛群自然岸线减少21.335 km,占原自然岸线的75.4%;岛群植被减少3.537 km2,占原岛群植被面积的74.0%。岛群变化大体划分为大鱼山主岛开发、大小鱼山连岛过程、岛群整体围填和岛群向东扩张围填四个阶段。前三阶段岛群自然岸线快速减少,人工岸线快速增加,第四阶段自然岸线缓慢减少,人工岸线长度冲高回落;岛群植被在前两阶段快速减少,后两阶段减少较慢;上述特征主要与工程施工过程有关。由于工程开发严重影响了岛群原有生态环境,建议海岛管理部门在岛群开发中应做好生态保护与修复工作。 相似文献
386.
The toxicity of nano-materials has received increasing attention in recent years.Nevertheless,relatively few studies have focused on their oceanic distributions and toxicities.In this study,we assessed nano-ZnO toxicity in marine organisms using the yellowstriped goby(Mugilogobius chulae).The relative differences in nano-ZnO dissolution and dispersal in seawater and fresh water were also investigated.The effects of nano-ZnO on embryonic development,deformity,hatching,mortality,and histopathology were analyzed.In addition,the effects of the Zn~(2+) concentration on M.chulae hatching and mortality were compared.The results showed that nano-ZnO had higher solubility in seawater than in fresh water.Nano-ZnO significantly inhibited hatching.By the fifth day of exposure,the LC_(50) of nano-ZnO was 45.40 mg/L,and the mortality rate spiked.Hatching inhibition and lethality were dose-dependent over a range of1–25 mg/L nano-ZnO.Zn~(2+) inhibited hatching and increased lethality,but its effects were weaker than those of nano-ZnO at the same concentrations.Nano-ZnO also induced spinal bending,oedema,hypoplasia,and other deformities in M.chulae embryos and larvae.Histopathology revealed vacuolar degeneration,hepatocyte and enterocyte enlargement,and morphological abnormalities of the vertebrae.Therefore,nano-ZnO caused malformations in M.chulae by affecting embryonic growth and development.We conclude that nano-ZnO toxicity in seawater was significantly positively correlated with the associated Zn~(2+) concentration and sedimentary behaviour.The toxicity of nano-ZnO was cumulative and showed a critical point,beyond which embryonic and developmental toxicity in marine fish was observed. 相似文献
387.
Nanoscale zero-valent iron(nZVI) assembled on graphene oxide(GO)(rGO-nZVI) composites were synthesized by reduction of GO and ferrous ions with potassium borohydride,for use in Cr(VI) removal from aqueous solution.The results showed that the two-dimensional structure of GO could provide a skeleton support for Fe~0,thus overcoming the bottleneck of aggregation for nZVI.Also,rGO-nZVI would form a ferric-carbon micro-electrolysis system in Cr(VI)-contaminated aquifers,enhancing and accelerating electron transfer,exhibiting high rate and capacity for Cr(VI) removal.The optimum dosage of the applied r GO-nZVI was linearly correlated with the initial Cr(VI) concentration.Characterization of rGO-nZVI before and after reaction with Cr(VI) revealed the process of Cr(VI) removal:r GO-nZVI firstly transferred electrons from Fe~0 cores via their Fe(II)/Fe(III) shells to the GO sheet;there,negatively charged Cr(VI) received electrons and changed into positively charged Cr(III),which was adsorbed by the negatively charged GO sheet,avoiding the capping and passivating of nZVI.rGO-nZVI formed a good electrically conductive network,and thus had long-term electron releasing properties,which was important for groundwater remediation. 相似文献
388.
Rui Han Shuxiao Wang Wenhai Shen Jiandong Wang Kang Wu Zhihua Ren Mingnong Feng 《环境科学学报(英文版)》2016,28(8):134-146
The purpose of this study is to analyze the climatic characteristics and long-term spatial and temporal variations of haze occurrence in China. The impact factors of haze trends are also discussed. Meteorological data from 1961 to 2012 and daily PM10 concentrations from 2003 to 2012 were employed in this study. The results indicate that the annual-average hazy days at all stations have been increasing rapidly from 4 days in 1961 to 18 days in 2012. The maximum number of haze days occur in winter (41.1%) while the minimum occur in summer (10.4%). During 1961-2012, the high occurrence areas of haze shifted from central to south and east regions of China. The Beijing-Tianjin-Hebei (Jing-Jin-Ji) region, Shanxi, Shaanxi, and Henan Province are the high occurrence areas for haze, while the Yangtze River Delta (YRD) and the Pearl River Delta (PRD) have become regions with high haze occurrences in the last 25 years. Temperature and pressure are positively correlated with the number of haze days. However, wind, relative humidity, precipitation, and sunshine duration are negatively correlated with the number of haze days. The key meteorological factors affecting the formation and dissipation of haze vary for high and low altitudes, and are closely related to anthropogenic activities. In recent years, anthropogenic activities have played a more important role in haze occurrences compared with meteorological factors. 相似文献
389.
为了研究氮添加对森林土壤有机碳氮组分稳定性的影响,选取我国亚热带典型常绿阔叶林(浙江桂天然林和罗浮栲天然林)和针叶林(杉木人工林),开展为期5年的野外模拟氮沉降试验,分别设置对照〔0 kg/(hm2·a),以NH4NO3中的N计,下同〕、低氮〔75 kg/(hm2·a)〕和高氮〔150 kg/(hm2·a)〕3个氮添加水平,用H2SO4分2步酸水解获得LPⅠ(活性有机库Ⅰ)、LPⅡ(活性有机库Ⅱ)和RP(惰性有机库),定量研究土壤活性和惰性有机碳氮组分以及微生物生物量碳氮对氮添加的响应. 结果表明:氮添加仅对w(LPⅡ-C)(LPⅡ-C为活性有机碳Ⅱ)有显著影响,而对其他活性和惰性有机碳氮组分的影响不显著,并且对不同林分的影响存在差异. 与对照处理相比,低氮处理下浙江桂天然林、罗浮栲天然林和杉木人工林土壤w(LPⅡ-C)的增幅分别为15.3%、29.8%、68.8%;高氮处理下杉木人工林土壤w(LPⅠ-C)(LPⅠ-C为活性有机碳Ⅰ)、w(LPⅠ-N)(LPⅠ-N为活性有机氮Ⅰ)和w(RP-C)(RP-C为惰性有机碳)的增幅分别为32.4%、78.6%、28.7%;氮添加使得土壤w(SMB-C)(土壤微生物生物量碳)的增幅为18.1%~202.5%、w(SMB-N)(土壤微生物生物量氮)的增幅为0%~103.6%;在氮添加处理下,除杉木人工林土壤SMB-N/LPⅠ-N〔w(SMB-N)/w(LPⅠ-N)〕是随着氮添加水平的增加而降低外,微生物对其他林分土壤活性有机氮的利用均表现为随着氮添加水平的增加而增加. 研究显示,氮添加对阔叶林和针叶林土壤活性和惰性有机碳氮组分的影响存在差异,但差异不显著,这与它们归还土壤的凋落物性质差异有关,并且凋落物的分解差异也可能是影响土壤不同碳氮组分变化的原因. 相似文献
390.
Pengjun Xu Bu Tao Zhiqiang Ye Hu Zhao Yue Ren Ting Zhang Yeru Huang Jiping Chen 《环境科学学报(英文版)》2016,28(10):102-111
The concentrations of 16 priority polycyclic aromatic hydrocarbons(PAHs) were measured in 23 farmland soil samples and 10 riverine sediment samples from Guiyu, China, and the carcinogenic risks associated with PAHs in the samples were evaluated. Guiyu is the largest electronic waste(EW) dismantling area globally, and has been well known for the primitive and crude manner in which EWs are disposed, such as by open burning and roasting. The total PAH concentrations were 56–567 ng/g in the soils and 181–3034 ng/g in the sediments.The Shanglian and Huamei districts were found to be more contaminated with PAHs than the north of Guiyu. The soils were relatively weakly contaminated but the sediments were more contaminated, and sediments in some river sections might cause carcinogenic risks to the groundwater system. The PAHs in the soils were derived from combustion sources,but the PAHs in the sediments were derived from both combustion and petroleum sources. 相似文献