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941.
采用原位监测野生鲫鱼外周血红细胞的微核发生率评价长江江苏段水污染的遗传毒性,并与实验室内的Cr(Ⅵ)诱变试验结果进行对比分析。结果表明,常熟望虞河口、江阴滨江村调查点的水污染对鲫鱼的遗传毒性最高,海门江心沙农场其次,江浦、江宁、靖江、镇江调查点的毒性最低。 相似文献
942.
943.
944.
《地表水环境质量标准》(GB 3838—2002)有20个元素项目,相应配套了33种分析方法。结合环境监测实际,探讨了GB 3838—2002存在的主要问题:15个元素项目23种分析方法不能满足Ⅰ类地表水监测,8个元素对应的18种分析方法相互矛盾,70%的分析方法没有结合当今仪器技术的革新而修订;19个元素项目指标概念模糊,同时分析方法的国际化程度低。针对GB 3838—2002中存在的问题,提出了一些启示性建议,为完善或修订GB 3838—2002提供参考。 相似文献
945.
F. Stagnitti G. Allinson M. Morita M. Nishikawa H. Il T. Hirata 《Environmental Modeling and Assessment》2000,5(4):229-236
Temporal moments analysis of solute breakthrough curves is used to investigate the preferential leaching of chloride, nitrate and phosphate through an Australian soil. Recent studies have shown that current models and methods do not adequately describe the leaching of nutrients through soil, often underestimating the risk of groundwater contamination by surface-applied chemicals, and overestimating the concentration of resident solutes. This inaccuracy results primarily from ignoring soil structure and non-equilibrium between soil constituents, water and solutes. Therefore simple models are required to accurately characterise solute transport in natural and agricultural soils under non-equilibrium conditions. A multiple sample percolation system, consisting of 25 individual collection wells was constructed to study the effects of localised soil heterogeneities on the transport of nutrients (NO3
–, Cl–, PO4
3
–) in the vadose zone of an agricultural soil predominantly dominated by clay. Using data collected from the multiple sample percolation experiments, this paper compares and contrasts the performance of temporal moments analysis with two mathematical models for predicting solute transport, the advective-dispersion model with a reaction term (ADR) and a two-region preferential flow model (TRM) suitable for modelling preferential transport. The values for solute transport parameters predicted by temporal moments analysis were in excellent agreement with experimental data and results from ADR and TRM. It is concluded that temporal moments analysis when applied with other physical models such as the ADR and TRM, provide an excellent means of obtaining values for important solute transport parameters and gaining insight of preferential flow. These results have significant ramifications for modelling solute transport and predicting nutrient loadings. 相似文献
946.
Lah B Vidic T Glasencnik E Cepeljnik T Gorjanc G Marinsek-Logar R 《Environmental monitoring and assessment》2008,139(1-3):107-118
Combining genotoxicity/mutagenicity tests and physico-chemical methodologies can be useful for determining the potential genotoxic
contaminants in soil samples. The aim of our study was to evaluate the genotoxicity of soil by applying an integrated physico-chemical-biological
approach. Soil samples were collected at six sampling points in a Slovenian industrial and agricultural region where contamination
by heavy metals and sulphur dioxide (SO2) are primarily caused by a nearby power plant. The in vitro alkaline version of the comet assay on water soil leachates was
performed with Caco-2 and HepG2 cells. A parallel genotoxicity evaluation of the samples was performed by Ames test using
Salmonella typhimurium and the Tradescantia micronucleus test. Pedological analyses, heavy metal content determination, and different physico-chemical analyses, were
also performed utilizing standard methodology. Water leachates of soil samples were prepared according to standard methods.
Since only a battery of biotests with prokaryotic and eukaryotic organisms or cells can accurately estimate the effects of
(geno)toxicants in soil samples and water soil leachates, a combination of three bioassays, with cells or organisms belonging
to different trophic levels, was used. Genotoxicity of all six water soil leachates was proven by the comet assay on both
human cell lines, however no positive results were detected by bacterial assay, Ames test. The Tradescantia micronucleus assay showed increase in micronuclei formation for three samples. According to these results we can assume that
the comet assay was the most sensitive assay, followed by the micronucleus test. The Ames test does not appear to be sensitive
enough for water soil leachates genotoxicity evaluations where heavy metal contamination is anticipated. 相似文献
947.
Aigars J Müller-Karulis B Martin G Jermakovs V 《Environmental monitoring and assessment》2008,138(1-3):313-326
Two approaches for setting ecological class boundaries, response curves and a simplified mathematical boundary-setting protocol,
were tested for coastal, transitional and open waters in the Gulf of Riga, Baltic Sea. The simplified mathematical boundary-setting
protocol defines acceptable ecological status based on expert judgment by a uniform relative deviation from reference conditions.
In contrast, response curves derive class boundary definitions from observed changes in biological quality elements along
environmental pressure gradients for class boundary definitions. Identification of relevant environmental pressures for the
construction of response curves was based on a conceptual model of eutrophication in the Gulf of Riga. Response curves were
successfully established for summer chlorophyll a and transparency, as well as for macrozoobenthos abundance in the Central
Gulf, macrozoobenthos biotic coefficient in the Southern Gulf, and maximum depth of phytobenthos in the Northern Gulf. In
the Gulf of Riga response curves almost always permitted a larger deviation from reference conditions than the 50% deviation
applied for the simplified mathematical boundary-setting protocol. The case study clearly demonstrated that class boundary
definitions should take into account the sensitivity of the target water body. Also, the class boundaries for different ecological
quality elements were internally more consistent than those derived by the simplified mathematical boundary-setting protocol. 相似文献
948.
针对工业场地有机氯污染土壤探索微生物修复的方法,试验表明:添加土著厌氧菌菌液及营养液的试验组,污染物去除率比空白组明显提高。基因测定结果显示,试验土壤中至少存在具有降解有机氯污染物能力的3种菌种。 相似文献
949.
Aiming at facilitating the research of urban tourism im- age positioning, this paper summarizes the domestic and abroad theories on urban tourism image and analyzes its significance for cities. With De... 相似文献
950.
首先进行了高温后钢管再生混凝土轴压短柱的试验研究,在分析试验结果的基础上提出了高温后核心再生混凝土的应力一应变关系模型,模型考虑了再生粗骨料取代率和曾经历的最高温度的影响;然后采用数值方法对高温后钢管再生混凝土轴压短柱的荷栽一变形全过程关系曲线进行了计算分析,数值计算结果得到试验结果的验证;最后利用数值方法系统分析了再生粗骨料取代率、曾经历的最高温度和约束效应系数等参数对高温后钢管再生混凝土短柱轴压强度系数的影响,并提出了相应的简化计算公式,轴压承载力的简化计算结果与试验结果基本吻合。 相似文献