排序方式: 共有11条查询结果,搜索用时 31 毫秒
1.
Franck Plourabou Pascal Kurowski Jean-Marc Boffa Jean-Pierre Hulin Stphane Roux 《Journal of contaminant hydrology》2000,46(3-4)
An experimental study of the transport properties of fluid-saturated joints composed of two complementary rough fracture surfaces, translated with respect to each other and brought in contact, is reported. Quantitative roughness measurements on different fractured granite samples show that the surfaces have a self-affine geometry from which the dependence of the mean aperture on the relative displacement of fracture surfaces kept in contact can be predicted. Variations of the hydraulic and electrical conductances of the joint are measured as functions of its mean aperture. A simple parallel plane model accounts for the global trend of the measurements, but significant deviations are observed when a relative lateral displacement of the surfaces is introduced. A theoretical analysis of their origin shows that they are due both to the randomness of the aperture field and to a nonzero local slope of the surface near the injection hole; the corresponding conductivity fluctuation amplitudes have power law and linear variations with the lateral displacement, and are enhanced by the radial injection geometry. 相似文献
2.
阐述了折光率法与电导率法测定稀土废水中高浓度氯化铵的原理和方法.在恒温和低悬浮物浓度条件下,折光率与氯化铵质量浓度线性关系良好;当保持外界条件不变时,氯化铵质量浓度在5 000 mg/L~60 000 mg/L与电导率显著相关.经t检验,两种方法与银量法差异均不显著,且操作简单,准确快速,适用于水处理过程中的现场实时监测. 相似文献
3.
Dunlop JE Horrigan N McGregor G Kefford BJ Choy S Prasad R 《Environmental pollution (Barking, Essex : 1987)》2008,151(3):621-630
Salinisation of freshwater has been identified as a serious environmental issue in Australia and around the world. Protective concentrations (trigger values) for salinity can be used to manage salinity impacts, though require locally relevant salinity tolerance information. 72-h acute salinity tolerance values were determined for 102 macroinvertebrates collected from 11 locations in four biologically distinct freshwater bio-regions in Northeast Australia and compared with sensitivities observed in Southeast Australia. The salinity tolerance of individual taxa was consistent across Northeast Australia and between Northeast and Southeast Australia. However, two distinct communities were identified in Northeast Australia using distributions of the acute tolerance values and a calculated index of salinity sensitivity. Salinity trigger values should therefore be representative of local or regionally relevant communities and may be adequately calculated using sensitivity values from throughout Eastern Australia. The results presented provide a basis for assessing salinity risk and determining trigger values for salinity in freshwater ecosystems at local and regional scales in Eastern Australia. 相似文献
4.
针对浙江省嘉兴市、湖州市长兴县、金华市金东区、绍兴市柯桥区开展农村生活污水水质调研工作,结果表明:农村生活污水进出水的电导率、TN、NH3-N、TP等指标间普遍存在极显著相关性.通径分析结果显示,TN的进出水直接通径系数分别为0.472 0、0.455 9,TN是影响进出水电导率的主要指标;电导率-TN含量的拟合方程经... 相似文献
5.
有机痕量分析的样品处理包括从样品采集直到最终分离测定的全过程,在有机痕量分析中,必须严格防止所用器皿、化学试剂、溶剂等污染,减少系统误差。 相似文献
6.
赤峰市降水电导率变化及其相关因素的探讨 总被引:3,自引:0,他引:3
通过对赤峰市自1988年以来的降水电导率资料统计分析,表明降水电导率的变化与风力大小,降水多少、植被覆盖程度和pH值密切相关。 相似文献
7.
Stewart AJ 《Environmental management》2001,27(1):37-46
Correlative relationships exist among conductivity, alkalinity, and hardness in streams due to natural geological and climatological
controls, but the relationships among these three water-quality factors can be altered strongly by inputs of ion-rich wastewaters.
The degree of alteration can be monitored conveniently by use of a simple chemical perturbation index, computed by subtracting
the sum of rank pairwise correlations among the conductivity, alkalinity, and hardness (for observations on each of these
variables, measured through time) from 3.0. The chemical perturbation index can be used to document or characterize spatiotemporal
changes in stream water quality. This study explains the development of the index's concept and provides examples of its application
in an extensive stream monitoring program used to assess ecological conditions in streams on the Department of Energy's Oak
Ridge Reservation in east Tennessee, USA. The chemical perturbation index technique may be particularly useful in community-based
stream monitoring programs because to its simplicity and low cost. 相似文献
8.
电导率的测定与质量监督工作 总被引:2,自引:0,他引:2
电导率、矿化度和总硬度密切相关。由此电导率的测定值可用来检验矿化度和总硬度测定值的准确性,加强质量控制,本文指出,电导率的测定应作为水样的首测项目。 相似文献
9.
Rock matrix diffusivity determinations by in-situ electrical conductivity measurements 总被引:1,自引:0,他引:1
A fast method to determine rock matrix diffusion properties directly in the bedrock would be valuable in the investigation of a possible site for disposal of nuclear waste. An "effective diffusivity borehole log" would provide important information on the variability of this entity over the area studied. As opposed to traditional matrix diffusion laboratory experiments, electrical conductivity measurements are fast, inexpensive and also easy to carry out in-situ. In this study, electrical resistivity data from borehole logging, as well as from measurements on the actual core, is evaluated with the purpose of extracting matrix diffusivity data. The influence of migration of ions in the electrical double layer, which can be of great importance in low ionic strength pore water, is also considered in evaluating the in-situ data to accurately determine the effective pore diffusivity. The in-situ data compare fairly well to those measured in the rock core. 相似文献
10.
Ejechi BO Olobaniyi SB Ogban FE Ugbe FC 《Environmental monitoring and assessment》2007,128(1-3):495-501
The physical (pH, Dissolved Solids, Dissolved Oxygen, conductivity, water depth temperature) and bacteriological (Total coliforms,
Faecal coliforms) characteristics of 22 hand-dug wells in oil-rich Niger Delta of Nigeria were investigated. All coliforms
counts (Log10 MPN/100 ml) varied from well to well ranging from 0 to 6.0 although faecal coliform counts were markedly lower (0–3.5 vs
1.0–6.0). When both seasons were compared, faecal coliform counts were significantly higher (t test; P < 0.05) during the wet season whereas no significant difference was observed in respect of total coliforms. Unlike the total
coliforms, faecal coliform counts increased in wells close to septic tanks during the wet season. Although a declining trend
was observed during the wet season, the values of the physical parameters were within WHO limits. The pH was slightly acidic
(Mean ± SD: dry season, 6.04 ± 0.66; wet, 6.43 ± 0.62) and may be attributed to emissions from gas flaring and petroleum refining
activities, which is common in the area. While the total coliform counts reflected the unsanitary habits of the well users,
the detection of faecal coliforms exceeding recommended numbers in 63% of the wells render them unfit for domestic use. The
public health implication is obvious considering the increasing number of people using the wells due to the rapid urbanization
of the oil-rich region. 相似文献