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971.
采用华丰矿1409工作面电磁辐射观测数据,应用相空间重构法计算了5次矿震前后系统混沌吸引子的关联维数D2。研究结果表明:电磁辐射时间序列具有混沌特征,混沌系统的自由度在2~26之间。矿震发生前,混沌吸引子的关联维数D2先升后降,矿震过程中系统有降维现象。研究结果对认识矿震过程中煤岩体产生的电磁辐射信号的非线性特征和进行矿震预报具有一定的参考价值。 相似文献
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973.
974.
OECD国家经验对我国排污收费制度的启示 总被引:2,自引:0,他引:2
我国现行排污收费制度虽发挥了筹集污染治理经费的功能,但未能达到促进污染物减排的功效。针对这一问题,借鉴OECD国家经验,提出国内应将排污收费标准提高至不低于治理成本;同时需根据成本的有效性确定收费对象。 相似文献
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976.
Hyun-Deok Choi 《Environmental pollution (Barking, Essex : 1987)》2009,157(5):1673-1678
Mercury (Hg) emissions from the soils taken from two different sites (deciduous and coniferous forests) in the Adirondacks were measured in outdoor and laboratory experiments. Some of the soil samples were irradiated to eliminate biological activity. The result from the outdoor measurements with different soils suggests the Hg emission from the soils is partly limited by fallen leaves covering the soils which helps maintain relatively high soil moisture and limits the amount of heat and solar radiation reaching the soil surface. In laboratory experiments exposure to UV-A (365 nm) had no significant effect on the Hg emissions while the Hg emissions increased dramatically during exposure to UV-B (302 nm) light suggesting UV-B directly reduced soil-associated Hg. Overall these results indicate that for these soils biotic processes have a relatively constant and smaller influence on the Hg emission from the soil than the more variable abiotic processes. 相似文献
977.
以眯唑类[PF6]^-型离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim][PF6])、1-己基-3-甲基咪唑六氟磷酸盐([Hmim][PF6])和1-辛基-3-甲基咪唑六氟磷酸盐([Omim][PF6])对苯胺、对氯苯胺等7种胺类化合物的萃取,考察了溶液初始浓度、相比、盐类、pH及离子液体眯唑基团上取代烷基对萃取平衡的影响,并研究了萃取过程的热效应。实验结果表明:溶液初始浓度对分配系数影响较小;相比10:1是离子液体对胺类化合物的溶解饱和临界点,当相比大于10:1时,分配系数降低;NaCl、K2SO4可以增大萃取分配系数,ZnSO4对分配系数几乎没有影响;pH增加,分配系数增大;离子液体对不同取代基的胺类萃取能力有较大的差异,咪唑基团上取代烷基的长度对不同胺类物质的分配系数影响较显著;萃取过程属于焓增大的吸热过程。 相似文献
978.
吉林省松花江中下游污染物排放总量控制 总被引:1,自引:0,他引:1
分析了实施总量控制的理论依据 ;并以此研究吉林省松花江中下游污染物总量控制以及吉林市控制单元的总量控制方案 ;最后探讨了总量控制措施。 相似文献
979.
Every mine in India has to obtain environmental clearance fromthe Govt. Air pollution is one of the most important parametersto be considered in preparing an EIA. However, there is no welldefined method for predicting thr air pollution impact due tomining. Increasing trend of opencast (O/C) mining leads toproduction of huge quantities of dust. Emission factor data havebeen utilised to quantify the generation of dust. The projectunder study is one of the largest opencast project (OCP) forcoking coal. The main sources of air pollution have beenidentified. The rate of emission per unit of a given activityknown as an emission factor has been utilised, taking localfactors into account. It has been estimated that due to topsoilremoval, overburden (O/B) removal, extraction of coal, sizereduction generated 7.8 t of dust per day. Wind erosiongenerated 1.6 t of dust per day and the whole operationproduced dust which accounted for 9.4 mt/day. They cause airpollution in the work zone and surrouding locations. Themethodology adopted may be used to quantify generation for otherprojects also. 相似文献
980.
This paper describes one example of how the UK National Air Quality Strategy (NAQS) is implemented in a local urban environment. The paper reviews the beginning of this process, by examining the review and assessment procedures of the NAQS in the London Borough of Barnet. By the application of available UK tools of local air quality management (LAQM), the process began through analysis of the levels of local emissions and progressed onto modelling of current and future air quality. A map showing combined emission hotspot areas for the Borough indicated and higher emission rates occur in the south of the Borough and along the major transport corridors, as road sources dominate emissions. Dispersion modelling studies were also conducted for this purpose, using the screening models GRAM, PGRAM and ADMS Urban for an in-depth assessment. These analyses found that some local point sources and the majority of Borough roads with over 20,000 vehicles per day produced exceedances of the future objectives for air quality for some pollutants.Recommendations for the progression of LAQM in the Borough are made and include the update and expansion of the emissions information held for use in future modelling studies. The paper demonstrates the experience of implementing the Strategy, using the tools and procedures available for this purpose, in a local urban environment that is similar to many in the UK. 相似文献