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水质的生化需氧量(BOD5)稀释与接种法测定结果不确定度评定 总被引:1,自引:0,他引:1
在实际工作中,运用测量过程的合并样本标准差来评定A类不确定度比较客观。本文根据JJF1059—1999《测量不确定度评定与表示》,通过实例,阐述了用稀释接种法测定水中生化需氧量不确定度的评定方法。 相似文献
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文章根据GB/T 4348.3—2002《工业用氢氧化钠铁含量的测定1,10—菲啰琳分光光度法》,以测试工业用氢氧化钠中铁含量为例,依据JJF1059—1999《测量不确定度评定与表示》与CNAS—GL06:2006《化学分析中不确定度的评估指南》对测量过程中不确定来源进行分析,采用A类、B类评定方法对各种因素引起的不确定度分量、合成不确定度、扩展不确定度进行评定,并给出评定结果。对理化分析领域测量不确定度具有借鉴意义。 相似文献
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目的 对原子荧光光谱法测定水中砷含量的不确定度来源及其对测量不确定度的影响进行分析。方法 利用相对标准不确定度进行测量不确定度的评定。过程采用直观的因果图,建立有效的数学模型,利用相对标准不确定度分量进行测量不确定度评定,并在砷含量为1.7μg/L的水样测定中,获得其相对标准不确定度为3.4%,有效自由度为25。结论 原子荧光光谱法对水中砷浓度测量不确定度影响因素中,工作曲线拟合产生的不确定度较大。 相似文献
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90Sr是高毒性的纯β放射性核素,其物理半衰期和生物半衰期长,环境气溶胶中的90Sr通过吸入途径进入人体,对人类的危害主要为长时间积集在人体骨骼中并很难排出。在多堆型核设施运行场址中环境气溶胶的测定是辐射环境监测的重要内容,也是评价核设施运行对环境影响的重要指标。为了科学评价环境气溶胶中测量结果的准确性和可靠性,进行了气溶胶中90Sr分析测量不确定度评定的方法研究,通过计算模型识别不确定度的来源,并对各分量进行量化分析,计算合成标准不确定度;结合典型样品分析实例,对环境气溶胶中90Sr分析测量的不确定度进行了评定,气溶胶中的分析测量采用的是色层萃取的方法,利用草酸钇沉淀制成样品源,测量样品中β计数率。不确定度评定结果表明:环境气溶胶中90Sr分析测量不确定度的来源主要有样品净计数率,探测效率,化学回收率,样品取样体积,测量期间半衰期修正;典型实例分析结果显示环境气溶胶中的相对标准不确定度可控制在15%内。文章中不确定度评定方法为气溶胶90Sr分析测量结果的不确定度评定提供参考。 相似文献
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在实验室分析基础上,对连续流动分析法测定水中总氮过程的不确定度进行评定。本文建立了数学模型,对不确定度来源进行了分析,并计算了不确定度分量、合成不确定度及扩展不确定度,最后给出了总氮测量结果的标准表示方法。 相似文献
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本文着重分析电磁兼容发射测量中的不确定度。以评定电源端子骚扰电压的不确定度为例,介绍发射测量不确定度的目的、不确定度源的种类、不确定度报告的评定方法及其Ucispr和不确定度在符合性判据中的运用。 相似文献
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Probe into the method of regional ecological risk assessment-a case study of wetland in the Yellow River Delta in China 总被引:18,自引:0,他引:18
Ecological risk assessment (ERA) is a new field of study for evaluating the risks associated with a possible eco-environmental hazard under uncertainty. Regional ERA is more complex than general ERA, as it requires that risk receptors, risk sources, risk exposure, uncertainty and especially spatial heterogeneity all be taken into account. In this paper, a five-step process of regional ERA is developed and tested through a wetland case study in the Yellow River Delta in China. First, indices and formulas are established for measuring degrees of ecological risk and damage to ecosystems. Using a combination of remote sensing data, historical records and survey data, and with the assistance of GIS techniques, the indices and formulas are then applied to the wetland in the study area. On the basis of the assessment results, we propose a number of countermeasures for the various risk zones in the Yellow River Delta. 相似文献
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This paper deals with the estimation of the shadow prices of pollutants with a nonparametric directional distance function approach, where the inefficiency involved in the production process is taken into account unlike the previous studies. The directional vector, which is critical to the estimation and subject to the criterion for an appropriate efficiency rule proposed here, is calculated by using the annual plans of power plants in terms of production and environment. In the empirical study for Korea's electric power industry during the period of 1990-1995, we find that the average shadow prices of sulfur oxides (SOx), nitrogen oxides (NOx), and total suspended particulates (TSP) are approximately 10% lower than those calculated under the assumption of full efficiency. The methodology we propose and the findings obtained in the empirical study allow us to undertake better decision-making over a broad range of environmental policy issues. 相似文献
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The use of guide to the expression of uncertainty in measurement for uncertainty management in National Greenhouse Gas Inventories 总被引:1,自引:0,他引:1
Research basis for annual greenhouse gases (GHG) emissions assessment is national and branch statistics data. Quality and confidence of greenhouse gases inventory through assessment methodologies, preparation procedures and processing of data is confirm. Request at National Greenhouse Gases Inventory which contain assessment and analyses uncertainty elements on Intergovernmental Panel on Climate Change-GPG 2000 and IPCC 2006 are determine. Main approaches for uncertainty assessment in environmental and metrological guides are considered. The algorithm of expressing uncertainty and scheme for estimating uncertainty according to GPG 2000 and IPCC 2006 are proposed. The use approaches GUM 1993 for uncertainty assessment for greenhouse gases inventory are proposed. 相似文献
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This paper presents a practical risk assessment methodology to provide drinking water infrastructure (DWI) decision-makers with an objective risk assessment tool. The purpose of this risk assessment tool is to maintain the desired level-of-service or systems reliability [r(f)], while managing the financial uncertainty of the expected budgetary impact within the capital improvement program (CIP). The goal of this paper is to demonstrate the value of an objective risk assessment tool for estimating the DWI decision-maker's sensitivity to the risk of systems failure (R). The objectives are to: (1) incorporate probability of systems failure [p(f)] into the CIP budgetary analysis process and (2) evaluate the affects of p(f) on the expected CIP budgetary outcome. The magnitude of the expected budgetary impact is managed through the DWI decision-maker's sensitivity to R, which is represented by the level of the rate of reinvestment (RR). The expected result of the proposed risk assessment tool demonstrates that by proactively managing R to maintain a desired r(f) will effectively manage the impact of uncertainty on the expected budgetary outcome within the CIP. The expected contribution of the practical risk assessment methodology is to provide DWI decision-makers with the ability to reduce budgetary uncertainty when allocating limited financial resources among competing operational, repair, maintenance, and expansion activities within the CIP. The conclusions of the paper reveal that if DWI decision-makers assume risk-avoidance positions through proactive asset management (AM) strategies, they will achieve positive affects on expected budgetary outcomes. 相似文献
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选取川南页岩气区块为研究对象,运用过程生命周期评估和投入产出生命周期方法核算页岩气开采生命周期的直接和间接用水量,并与美国Marcellus页岩气区块用水量进行比较。川南区块总直接用水量为22 928 m^3/井,高于Marcellus区块的总直接用水量15 320 m^3/井。从生命周期阶段来看,川南页岩气开采钻井和压裂阶段的直接用水均远大于Marcellus区块。结合水环境管理指标,自然资源禀赋条件主要决定了直接用水量的差异。川南区块总间接用水量为25 098 m^3/井,超过总直接用水量,约为Marcellus区块总间接用水量的3倍。除井场准备阶段外,其余阶段的间接用水量均大于Marcellus区块,间接用水量的差异与钻井和压裂过程的添加剂、能源使用量和全行业用水效率有关。减少川南区块页岩气开发用水量的主要途径包括提高钻井液和压裂液回用率、改善钻井和压裂添加剂使用效率、提高柴油和电力等能源利用效率和全行业用水效率。 相似文献
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Spatially explicit sensitivity and uncertainty analysis for multicriteria-based vulnerability assessment 总被引:1,自引:0,他引:1
Bakhtiar Feizizadeh Stefan Kienberger 《Journal of Environmental Planning and Management》2017,60(11):2013-2035
This research analyses the application of spatially explicit sensitivity and uncertainty analysis for GIS (Geographic Information System) multicriteria decision analysis (MCDA) within a multi-dimensional vulnerability assessment regarding flooding in the Salzach river catchment in Austria. The research methodology is based on a spatially explicit sensitivity and uncertainty analysis of GIS-CDA for an assessment of the social, economic, and environmental dimensions of vulnerability. The main objective of this research is to demonstrate how a unified approach of uncertainty and sensitivity analysis can be applied to minimise the associated uncertainty within each dimension of the vulnerability assessment. The methodology proposed for achieving this objective is composed of four main steps. The first step is computing criteria weights using the analytic hierarchy process (AHP). In the second step, Monte Carlo simulation is applied to calculate the uncertainties associated with AHP weights. In the third step, the global sensitivity analysis (GSA) is employed in the form of a model-independent method of output variance decomposition, in which the variability of the different vulnerability assessments is apportioned to every criterion weight, generating one first-order (S) and one total effect (ST) sensitivity index map per criterion weight. Finally, in the fourth step, an ordered weighted averaging method is applied to model the final vulnerability maps. The results of this research demonstrate the robustness of spatially explicit GSA for minimising the uncertainty associated with GIS-MCDA models. Based on these results, we conclude that applying the variance-based GSA enables assessment of the importance of each input factor for the results of the GIS-MCDA method, both spatially and statistically, thus allowing us to introduce and recommend GIS-based GSA as a useful methodology for minimising the uncertainty of GIS-MCDA. 相似文献
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This paper gives an overview of systems analysis and modeling applied to water resource management. With increased concern for economic efficiency in water resource usage, the need to exploit the complementary nature of various modes of usages has become more important. Systems analysis is particularly helpful in this regard because assessment of the relative allocation of costs and benefits of two more potential uses requires a systems framework. The process of systems analysis for comprehensive water planning is discussed outlining recognition of the problems, definition of a model, questions of data collection and finally implementation of a practical program of action. The methodology and advantages of water resources systems analysis are discussed relative to three main areas of concern - hydrologic uncertainty, objectives of governments and sponsoring agencies, and overlapping institutional and political boundaries. 相似文献
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Philip R. Maul Richard Metcalfe Jonathan Pearce David Savage Julia M. West 《International Journal of Greenhouse Gas Control》2007,1(4):444-455
The geological storage of carbon dioxide is currently being considered as a possible technology for reducing emissions to atmosphere. Although there are several operational sites where carbon dioxide is stored in this way, methods for assessing the long-term performance and safety of geological storage are at an early stage of development. In this paper the similarities and differences between this field and the geological disposal of radioactive wastes are considered. Priorities are suggested for the development of performance assessment methods for carbon dioxide storage based on areas where experience from radioactive waste disposal can be usefully applied. These include, inter alia, dealing with the various types of uncertainty, using systematic methodologies to ensure an auditable and transparent assessment process, developing whole system models and gaining confidence to model the long-term system evolution by considering information from natural systems. An important area of data shortage remains the potential impacts on humans and ecosystems. 相似文献