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951.
Environmental Science and Pollution Research - Humans are exposed to the variety of emerging environmental pollutant in everyday life. The special concern is paid to endocrine disrupting chemicals...  相似文献   
952.
Five centuries of mining and processing of mercury ore in the Idrija area have resulted in widespread contamination of different environmental compartments. Environmental impacts on a regional and local scale, caused by atmospheric emissions from the Idrija ore roasting plant, were established in the investigations of mercury spatial distribution in soil and attic dust in 160 km(2) area. Very high values were determined in the Idrijca River valley, and they decrease exponentially with the distance from Idrija. Mercury concentrations in attic dust are higher than in surrounding soils and the attic dust/soil ratio changes with distance. Measurements of mercury in the air confirmed widespread dispersion of mercury and showed highly elevated mercury concentrations around roasting plant and mine ventilation shaft. Beside, systematic monitoring of mercury contents in the stream sediments has demonstrated that huge amounts of mercury are stored in areas where ancient overbank sediments were deposited, and there was no decrease in mercury concentration in active sediments during the last 15 years. Recently, interesting and extremely polluted locations of historical small-scale roasting sites in the Idrija surroundings were discovered. Ongoing geochemical study aims to determine the extreme pollution and significance of these sites for wider contamination of soils and aquatic systems. Presented studies have shown that Hg mining in Idrija caused intense pollution of local and regional environment including the aquatic systems in the Gulf of Trieste, which is seen as the final sink of a major part of the Hg stored in soils and river sediments in the Idrija area.  相似文献   
953.
The study conducted in the Morinje Bay (Central Dalmatia, Croatia) included the investigation of the sedimentological, physico-chemical and geochemical properties of the Morinje Bay sediments in order to assess the suitability of the material for wellness-related purposes including medicinal use. The sedimentological characteristics of the Morinje mud are in accordance with the geological origin of the material; the sediment is fine grained, composed mostly of carbonates, quartz and clay minerals. The composition of the sediment determines the physico-chemical properties of the mud. The high content of carbonate minerals diminishes adsorbing the characteristics of the mud to some extent; however, they are still comparable to some commercial mud already successfully used for medicinal purposes. Geochemical analyses have shown that trace metals concentrations in the Morinje Bay samples were mostly in the range with similar material from unpolluted Adriatic environments. Only the concentrations of Cu, Pb, Zn and As were slightly higher than in the reference material, but still within acceptable limits.  相似文献   
954.
种植密度对不同株型玉米生长及根系形态特征的影响   总被引:4,自引:0,他引:4  
选取平展型(ND108)、紧凑型(ZD958)、小株小穗型(CF008)玉米品种,采用PVC管土柱法种植,密度为1株/盆、2株/盆和3株/盆,探讨种植密度对不同株型玉米的生长特性及根系形态的影响.结果表明:种植密度增加,不同株型玉米个体生长均受到抑制,各项根系形态指标显著降低(P<0.01),但较低幅度增密对平展型品种(ND108)根系各项形态指标无显著影响;种植密度对不同株型玉米品种比根长(SRL)与比根表面积(SRS)的影响程度有显著差异,对平展型品种(ND108)影响最大,对紧凑型品种(ZD958)影响最小;穗根比、根系生物量分配比例存在显著基因型差异,平展型品种(ND108)较其它两个品种具有较高的根系干物重分配比例,但其穗根比较低.综上,增密过程中平展型品种(ND108)倾向于通过形成庞大根系以提升单株竞争能力,但是个体间激烈的竞争将限制群体产量的提高;而紧凑型品种(ZD958)和小株小穗型品种(CF008)个体间竞争较弱,因而在群体压力增大时能够通过增强自身根系的吸收能力以保证对地上部水分、养分供应,有可能获得更高的群体产量.  相似文献   
955.
以MgSO4?7H2 O和Na2 HPO4?12H2 O作为沉淀剂加入到垃圾渗滤液中,形成磷酸铵镁沉淀,可有效去除渗滤液中氨氮含量。最佳反应条件为:pH =9.5、Mg∶N =1.8∶1,P :N =1.8∶1,在此条件下 NH3- N 去除率达97%,COD 的去除率达到20%。  相似文献   
956.
The bottlenose dolphin (Tursiops truncatus) is the most common cetacean species worldwide and the only marine mammal species resident in the Croatian part of the Adriatic Sea. To gain insight into genetic diversity of bottlenose dolphins at adaptively important loci relevant to conservation, we analysed the polymorphism of major histocompatibility complex (MHC) genes, which play a key role in pathogen confrontation and clearance. Specifically, we examined the diversity of MHC class II DRA, DQA and DQB alleles in 50 bottlenose dolphins from the Adriatic Sea collected between 1997 and 2011 and in 12 animals from other Mediterranean locations. Notable variation in DQA, DQB and three-locus haplotypes was found, with all 10 DQA and 12 DQB alleles encoding unique protein products. Analysis of the ratio of non-synonymous to synonymous substitution rates suggests that positive selection acts at both highly variable loci. Phylogenetic analyses revealed trans-species polymorphism at the DQB locus, strongly indicating the influence of balancing selection in the long term. In fact, the balancing selection observed in bottlenose dolphins is higher than that reported for most other cetaceans and comparable to that seen in terrestrial mammals.  相似文献   
957.
四川省部分地区土壤中六溴环十二烷的分布特征   总被引:1,自引:0,他引:1  
利用高效液相色谱-串联四极杆质谱分析了我国四川省中北部地区(成都、德阳、绵阳)表层土壤中六溴环十二烷(HBCD)的浓度水平和分布特征.成都、德阳、绵阳等3个地区土壤中HBCD的平均浓度分别为77.0 pg·g-1dw(相似文献   
958.
Groundwater pumping can reduce the flow of surface water in nearby streams. In the United States, recent awareness of this externality has led to intra- and inter-state conflict and rapidly-changing water management policies and institutions. Although the marginal damage of groundwater use on stream flows depends crucially on the location of pumping relative to streams, current regulations are generally uniform over space. We use a population data set of irrigation wells in the Nebraska portion of the Republican River Basin to analyze whether adopting spatially differentiated groundwater pumping regulations leads to significant reductions in farmer abatement costs and costs from damage to streams. We find that regulators can generate most of the potential savings in total social costs without accounting for spatial heterogeneity. However, if regulators need to increase the protection of streams significantly from current levels, spatially differentiated policies will yield sizable cost savings.  相似文献   
959.
大型原油商业储备油库火灾危险性数值模拟分析   总被引:3,自引:1,他引:2       下载免费PDF全文
石油储备油库多向大型化、复杂化方向发展,发生事故时扑救非常困难。为了深入探讨巨型油罐火灾发展趋势与规律、事故危害后果,结合宁夏惠安堡原油商业储备油库这一工程实例,采用基于大涡模拟的FDS模型作为模拟计算平台,对巨型油罐火灾的燃烧过程进行数值模拟计算。通过分析计算,得到烟气分布、温度分布、热辐射强度分布等火灾过程参数的变化趋势,以及在有风和无风状态下着火罐对相邻油罐的影响,探讨现行建设工程消防技术标准就储罐防火间距、火灾时对邻近罐体冷却设计要求运用于巨型储油罐时的消防安全状况,为巨型储油罐消防安全科学合理设计提供理论依据。  相似文献   
960.
Abstract

INA‐Petrochemical Industry Omi?alj, Yugoslavia is currently producing low density polyethylene, vinyl chloride monomer and ethylene dichloride.

Because of a potentially great hazard for environmental pollution, particularly by low molecular weight chlorinated hydrocarbons, the company has been putting significant effort into its anti‐pollution programme.

Modern technology, polyfunctional organization and proper control of all waste materials has enabled, thus far, no evident or noticable impact on the environment.

Wastewater treatment from the source to final discharged effluent and environmental control results are described.  相似文献   
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