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作业场所粉尘浓度、呼吸性岩(煤)尘接触浓度及管道粉尘浓度等矿山常用的三种质量浓度及其现行标准是矿山企业安全生产及防尘技术管理的常用指标。该从基本概念出发,以实用为目的,重点介绍三种质量浓度的计算、测试方法及其现行标准。 相似文献
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本文简述了大气污染与气溶胶的关系,论述了平流层气溶胶对地球辐射收支的影响,从而说明平流层气溶胶的光学性质的变化将影响全球大气环境,在此基础上,计算了不同背景平流层气溶胶的光学常数和光学特性参数。并使用模式光学常数计算了3种火山模工气溶胶的光学特性参数。同时,考察了这些特性参数对光学常数的敏感性。结果表明,后向散射系数对光学常数的变化最敏感,对于某些波长,它的相对变化可比光学常数的相对变化大一个数量 相似文献
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本文分析了《地面水质量标准》(GB3838—88)中非离子及氨查表换算法可能的缺点,介绍了一种仅用计算式可快速、准确计算5—30℃水温,pH=6.0~10.0范围内任意温度、任意pH值时非离子氨百分比、允许总氨浓度,非离子氨浓度的方法,并具体计算与文献值比较,结果表明此计算式是正确和简便实用的。 相似文献
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简论废气氮氧化物(NO_X)浓度单位PPm与mg/m~3的换算系数关系 总被引:4,自引:0,他引:4
空气中污染物浓度的表示方法有两种,体积浓度表示法(ppm)与质量浓度表示法(mg/m3)。氮氧化物不是单一的化合物,存在多种化合物。因此目前对氮氧化物(NOX)单位换算不清,造成浓度结果计算错误。本文对这一问题作一简介。 相似文献
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目前电导率测定在实验室是一个十分普遍而重要的项目,标定电极常数的方法有直接测定法和比较测定法。在直接测定法的基础上,针对现代数显电导仪的特点,设计了标准溶液直读法标定电极常数,绕过了标定过程中需要测定电导G(电阻)的步骤。该方法直观易懂,操作简单,不需要计算,省时省力,适用于所有需要调节并能读出该电极常数的电导率仪。 相似文献
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《新疆环境保护》2020,(3)
应用显微镜法、PMF模型、稳定同位素三种源解析方法,对乌鲁木齐典型人群密集区域颗粒物进行溯源解析分析,并比较三种方法的特点及结果。结果表明:利用显微镜法对颗粒进行定性分析,得到乌鲁木齐典型区域颗粒物污染主要为烟尘集合体、燃煤飞灰、矿物颗粒、硝酸盐等;利用PMF进行源解析分析得到颗粒物主要来源于城市扬尘、机动车、工业源及燃烧源及二次颗粒物;利用稳定同位素法进行源解析得到颗粒物主要来源于八钢、石化、电厂、道路、机动车排放。三种方法的结果存在一定差异,显微镜法初步判定区域颗粒物中污染物种类,PMF模型可分析计算不同污染源的贡献率,稳定同位素法进一步分析计算主要污染行业贡献率。 相似文献
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采用最速下降法和复合形法对河流动态水质模型的参数进行了优化估算,并从计算方法的适用范围、计算机编程的复杂程度,整体工作量的大小,计算结果的代表性合理性等方面对这两种方法进行了比较分析。 相似文献
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近年来我国的环境问题日益引人注目,大气污染问题显得尤为突出。空气质量预测技术方法能够提前预测区域空间内的大气污染物浓度,其发展十分迅速。本文介绍了一些国内外常用的空气质量预测技术方法的原理及案例,对其结果与局限性进行归纳总结,并对其未来发展提出展望。空气质量预测技术方法分为两类:数值模拟和统计学习,数值模拟通常可以分为第一代、第二代和第三代空气质量模型,统计学习可以分为简单经验统计和机器学习。两类方法的目的都是尽可能真实、准确地实现特定时间、特定区域范围内大气污染物浓度的预测,但两类方法的原理算法差异较大。该研究系统梳理了空气质量预测技术方法演变的历程和发展的现状,展望了其发展趋势,分析了建立、健全空气质量预测技术标准规范体系的重要性,提出了相关参考建议。 相似文献
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J. W. Gary C. S. Simmons J. F. McBride 《Journal of the American Water Resources Association》1989,25(6):1205-1216
ABSTRACT: The conductivity of air, mineral oil (relative viscosity 77), and a light nontoxic oil (relative viscosity 4.7) was measured in three porous media: a sand, loamy sand, and a silt loam. The measurements were made over a range of water contents for each porous medium. Small volumes of air were present as well as significant amounts of water during most of the oil conductivity measurements. The results were compared to two methods for calculating conductivities of immiscible fluids in water-wet porous media. A new equation that accounts for swelling and for the gas slippage effect in very small pores was formulated for use with these methods The observed conductivities, spanning seven orders of magnitude, agree reasonably well with calculated values. Only three soil parameters are required to calculate the conductivities: (1) the saturated conductivity of water, (2) the saturated conductivity of the immiscible fluid of interest, and (3) a pore size index value that is obtained from an estimate from the water release curve of the porous material. Remediation of organic liquid spills is briefly discussed to illustrate the practical applications of gas phase conductivities, as well as those for immiscible organic liquid phases. It is concluded that, in light of spatial variation under field conditions, the method presented for calculating values of three-phase conductivities will be useful in the management of immiscible organic liquid spills and leaks. 相似文献
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Kathleen J. Miller 《Journal of the American Water Resources Association》2005,41(2):257-265
ABSTRACT: A series of gravel terraces support a shallow aquifer that is the sole source of drinking water for three public water supplies and more than 400 private wells on the Greenfields Bench in west‐central Montana. Farming practices on the Greenfields Bench include irrigation of malting barley and the yearly application of herbicides for the control of weeds. The most commonly used herbicide (imazamethabenz‐methyl, U.S. trade name Assert®) has been found in the ground water on the Greenfields Bench. An experiment was conducted in 2000 and 2001 to characterize the transport of Assert and its acid metabolite to ground water under three irrigation methods: flood, wheel line sprinkler, and center pivot sprinkler. Results show that Assert concentrations in ground water are controlled by hydraulic loading rates of each irrigation method, Assert persistence in soil, hydraulic characteristics of the aquifer, and adsorption/desorption of Assert onto clay particles and organic matter. 相似文献
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Bamidele Sunday Fakinle Oyetunji Babatunde Okedere Sunday Adekunle Adebanjo Adewole Johnson Adesanmi Jacob Ademola Sonibare 《环境质量管理》2019,28(3):97-102
An emissions inventory and the AERMOD View dispersion model were used to estimate the concentrations and the potential effects of carbon monoxide (CO) from diesel engine electric power generators operated by and providing electricity to a textile factory in Nigeria on its host air shed. The CO emissions from simultaneous operations of all of the electric power generators in the factory resulted in: 1‐hr average CO emissions of 4.2 to 54.5 micrograms per cubic meters (μg/m3) and 24‐hr average CO emissions of 0.3 to 20.9 μg/m3. The estimated 1‐hr averaging period maximum ground‐level concentrations of CO were deposited within the factory, while the 24‐hr maximum ground‐level concentrations are estimated at a distance 90 meters (m) from the factory in a southeast direction. The ground‐level concentrations of CO emanating from the textile factory are within the stipulated ambient air quality standards. 相似文献
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One of the objectives of the new State of Croatia, as a Mediterranean country oriented towards tourism, is safety of its air traffic. The frequency of use of Zagreb airport is currently 688 flights, or about 20000 passengers a week. In 1996, research was carried out at the airport concerning air traffic safety with respect to the presence of birds on the airfield. Biological methods, in which birds were chased away by means of trained birds of prey, were used. For the Zagreb airport experiment nine birds involving three different species: Falco peregrinus, Accipiter gentilis and Falco cherrug were utilised. The results showed that the air traffic safety on Zagreb airport with regard to possible bird-plane strikes improved.Other bird clearing methods, applied over the 1987–1996 period also reduced bird-plane interferences but were noted to be less effective. With the biological, bird of prey method, 100% temporary clearance was achieved. Habitat modification, which involved removal from the airport vicinity of all factors attractive to the birds, only removed 20–30% of the birds, but this was of a more permanent nature. Use of fire-arms achieved a 80–90% temporary bird clearance. A combination of all three methods would appear to be most effective and measures for further monitoring for safe air traffic movement at Zagreb airport are proposed. 相似文献
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吴邦灿 《中国环境管理干部学院学报》2000,(2)
我国空气质量监督方式尚不统一,出现了三套数据的可比性问题。本文通过对这三种运行方式的经济技术特点分析,提出淘汰“五日法”、规范“24小时”法、发展自动连续监测和遥感监测的建议。 相似文献
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北戴河空气负离子浓度测定与负离子评价标准 总被引:4,自引:0,他引:4
本文介绍了空气负离子及其在清洁空气、抗菌和卫生保健方面的作用,通过对北戴河地区六处景点的空气负离子浓度进行测定,制定了评价空气负离子浓度的七级评价标准体系,提出在充分利用自然环境中所形成空气负离子的卫生保健作用的同时,创制释放负离子纤维织物,制造随身携带的负离子发生器,构筑健康万里长城。 相似文献