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991.
992.
Ping Li Xinbin Feng Guangle Qiu Junfang Zhang Bo Meng Jianxu Wang 《Environmental science and pollution research international》2013,20(12):8374-8381
Mercury (Hg) speciation and mobility were determined in calcines and waste rocks collected from 9 Hg mines in China. Total Hg (THg) concentrations in the mine wastes varied widely in different Hg mines (with a range of 0.369 to 2,620 mg kg?1). Cinnabar is the dominant form of Hg in the mine wastes. However, Hg2+ and Hg0 concentrations in the calcines were significantly higher than these in the waste rocks, which suggested the retorting can produce large amounts of by-product Hg compounds. The THg and Hg0 concentrations in certain mine wastes exceeded soil guidelines recommended by US Environmental Protection Agency; while total soluble Hg concentrations of leachates in certain mine wastes exceeded National Surface Water Quality Standard of China. Mine wastes are important Hg pollution sources to the aquatic ecosystem and atmosphere. 相似文献
993.
994.
CAWS600自动气象站工作作业维护程序探讨 总被引:3,自引:0,他引:3
自动气象站是北京自然环境试验站中的一个工作项目。本文阐述了该.工作的职责和重要性及设备作业维护要求。分析了自动站发展过程中的问题,讨论了一下发展方向,需要实现资源共享和提高自动站的效益。 相似文献
995.
Löfgren S Aastrup M Bringmark L Hultberg H Lewin-Pihlblad L Lundin L Karlsson GP Thunholm B 《Ambio》2011,40(8):836-856
Recovery from anthropogenic acidification in streams and lakes is well documented across the northern hemisphere. In this
study, we use 1996–2009 data from the four Swedish Integrated Monitoring catchments to evaluate how the declining sulfur deposition
has affected sulfate, pH, acid neutralizing capacity, ionic strength, aluminum, and dissolved organic carbon in soil water,
groundwater and runoff. Differences in recovery rates between catchments, between recharge and discharge areas and between
soil water and groundwater are assessed. At the IM sites, atmospheric deposition is the main human impact. The chemical trends
were weakly correlated to the sulfur deposition decline. Other factors, such as marine influence and catchment features, seem
to be as important. Except for pH and DOC, soil water and groundwater showed similar trends. Discharge areas acted as buffers,
dampening the trends in streamwater. Further monitoring and modeling of these hydraulically active sites should be encouraged. 相似文献
996.
三峡库区香溪河库湾沉积物重金属污染特征 总被引:7,自引:0,他引:7
2010年3月在三峡水库香溪河库湾获取了无扰动沉积物柱状样,在香溪河口的长江干流(长江右岸)获取了表层沉积物样,现场进行了环境因子测量和室内粒度分析、矿物分析、重金属元素含量分析。沉积物矿物以绿泥石、伊利石和石英为主,占到全部矿物的65%左右。柱状沉积物pH值随深度增加呈现变小的趋势,Eh值也有随深度减少的趋势,反映了环境还原性加强。R-型因子分析结果表明:重金属元素的含量随粒径变细、绿泥石和伊利石含量增加而增加,而随石英、白云石含量增加而降低;且重金属元素含量变化与pH值密切相关,当pH值下降时部分重金属容易重新释放出来而进入环境中。库湾下游具有较中上游高得多的重金属含量,沉积物中重金属的污染程度为无污染到轻度污染,且轻度污染出现于下游至干流。三峡水库蓄水前香溪河沉积物中重金属含量顺序大致为Zn>Pb>Cu>As>Cd,而蓄水后香溪河及干流沉积物均表现为Cu含量高于Pb。 相似文献
997.
In this paper,the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight developed countries.Then,the authors run a regression on the impact of decisive factors of economic growth on energy intensity and its change,so as to find out the economic mechanism of energy intensity gap changing with respect to the variation of economic growth.This study concludes that:First,there is a convergence in per capita GDP gap between China and the eight developed countries.With the convergence in per capita GDP gap,the energy intensity gap between China and eight different countries also converge,and the convergence rate of the latter is faster than that of the former,i.e.if the per capita GDP gap between China and the eight developed countries decreases by 1%,the energy intensity gap between them will correspondingly decrease by 1.552%.Second,the energy intensity decreases with the improvement of industrial structure,the rising of energy prices,the advances of technology,and the expansion of investment in fixed assets,and it slightly increases with the increase of FDI.Third,the energy intensity gap between China and eight developed countries narrows with the lessening of the difference in fixed assets investment,energy prices,and technological progress between China and eight developed countries,yet increases with the narrowing of the difference in FDI,and has no significant correlation with the difference in industrial structure.Fourth,the narrowing of difference in per capita GDP between China and the eight developed countries can result in the lessening of energy intensity gap,whose economic mechanism is that the decisive factors,such as difference in investment,technology,and the competition mechanism of prices,which can determine the difference in economic growth,can significantly affect the energy intensity gap. 相似文献
998.
土壤微生物是表征土壤质量最有潜力的敏感性指标,高质量的土壤应具有稳定的微生物群落组成和结构、高微生物生物量及良好的微生物活性。本文从微生物的群落组成与多样性、微生物生物量和微生物活性3个方面进行了综述。微生物指标研究目前任务是确定一套评价土壤质量的微生物学指标最小参数集。建议今后加强土壤样品收集、储存、预处理及分析方法规范化,深层土壤微生物对土壤质量的作用及建立本底土壤微生物属性数据库等方面的研究。 相似文献
999.
1000.