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71.
含油污泥调剖技术在陇东油田悦29区的应用   总被引:3,自引:2,他引:1  
针对长庆陇东油田悦29区注水平面矛盾突出的特点,优选了含油污泥调剖技术。详细介绍了调剖体系的配制,调剖体系性能测试表明其相关性能指标满足要求。进行了驱替模拟试验,结果表明:其封堵作用可以维持较长时间,通过对不同注水井组进行现场应用,显示该技术能改善水驱开发效果,可以满足油藏深部封堵大孔道的技术要求,有增油降水效果。  相似文献   
72.
Review of state of the art methods for measuring water in landfills   总被引:1,自引:0,他引:1  
In recent years several types of sensors and measurement techniques have been developed for measuring the moisture content, water saturation, or the volumetric water content of landfilled wastes. In this work, we review several of the most promising techniques. The basic principles behind each technique are discussed and field applications of the techniques are presented, including cost estimates. For several sensors, previously unpublished data are given. Neutron probes, electrical resistivity (impedance) sensors, time domain reflectometry (TDR) sensors, and the partitioning gas tracer technique (PGTT) were field tested with results compared to gravimetric measurements or estimates of the volumetric water content or moisture content. Neutron probes were not able to accurately measure the volumetric water content, but could track changes in moisture conditions. Electrical resistivity and TDR sensors tended to provide biased estimates, with instrument-determined moisture contents larger than independent estimates. While the PGTT resulted in relatively accurate measurements, electrical resistivity and TDR sensors provide more rapid results and are better suited for tracking infiltration fronts. Fiber optic sensors and electrical resistivity tomography hold promise for measuring water distributions in situ, particularly during infiltration events, but have not been tested with independent measurements to quantify their accuracy. Additional work is recommended to advance the development of some of these instruments and to acquire an improved understanding of liquid movement in landfills by application of the most promising techniques in the field.  相似文献   
73.
Gu C  Jiang X  Ju X  Yu G  Bian Y 《Chemosphere》2007,67(7):1325-1334
DFT-B3LYP method with 6-31G(**) basis set was employed to fully optimize the electronic structures of 135 polychlorinated dibenzofurans and parent compound, namely dibenzofuran. It was demonstrated that polarizability anisotropy and mean polarizability could change sensitively and systematically with chlorine number and substitution pattern. And new quantitative structure-activity relationships (QSARs) focused on the binding affinities of aryl hydrocarbon receptor (AhR), aryl hydrocarbon hydroxylase (AHH) and 7-ethoxyresorufin O-deethylase (EROD) induction potencies of PCDFs were developed. It was concluded that polarizability anisotropy in conjunction with hyperpolarizabilties and hyper-order electric moments, e.g. octupole moments could well interpret the variation of toxicity of different congeners and dispersion interaction should be the leading form among various interactions. Although the terms of hyperpolarizabilities and hyper-order electric moments were not the same significant ones as polarizability anisotropy, the long-range interactions characterized by them should not be ignored in explaining the toxicity.  相似文献   
74.
Ambient air monitoring of PCDD/Fs and co-PCBs in Gyeonggi-do, Korea   总被引:3,自引:0,他引:3  
Kim DG  Min YK  Jeong JY  Kim GH  Kim JY  Son CS  Lee DH 《Chemosphere》2007,67(9):1722-1727
We started the monitoring for PCDD/Fs in ambient air and soil in August 2001, and co-PCBs in January 2002. Decreasing of PCDD/Fs and co-PCBs levels in ambient air were observed. The higher PCDD/Fs levels were found in winter and lower in autumn. We found that the industrial incinerators influenced the PCDD/Fs levels in ambient air. In the 2,3,7,8-substituted PCDD/Fs concentration profiles, the three major congeners occupied 67% of the total mass. In case of co-PCBs, PCB#118, #105 and #77 were observed as the main congeners. Five cluster groups discriminated by ratio of four components, O(8)CDD, 1,2,3,4,6,7,8-H(7)CDD, 1,2,3,4,6,7,8-H(7)CDF and O(8)CDF, were obtained from HCA (hierarchical cluster analysis).  相似文献   
75.
光污染已经成为继水污染、大气污染、噪声污染、固体废物污染之后的第五大污染.是21世纪直接影响人类健康的又一环境杀手!  相似文献   
76.
影响马尾松毛虫虫灾发生类型因素的重要性分析   总被引:4,自引:1,他引:3  
运用列联表分析方法探讨了小班的林地起源、优势树种、地理、生长等因素对小班的马尾松毛虫虫灾发生类型的影响。分析结果表明:小班的海拔高度和坡度是决定小班的马尾松虫灾发生类型的关键因素。小班的优势种结构、平均树高及郁闭度对小班的马尾松毛虫虫灾发生类型也有较大的影响。图12表1参2  相似文献   
77.
接种Glomus versiforme对红三叶草利用有机磷的影响   总被引:1,自引:1,他引:0  
以红三叶草为材料,利用三室隔网培养方法,研究接种菌根真菌Glmous versiforme对土壤有机磷及外加有机磷化合物植酸钠(Na-Phytate)、核糖核酸(RNA)和卵磷脂(Lecithin)的利用效率,植株生长7wk后收获测定植标干物重、含磷量和根系菌根侵染率,结果表明:接种菌根真菌能明显增加植株干物重、含磷量和吸磷总量,与各有机磷处理相比,无机磷(KH2PO4)处理生长效应最好,施用有机磷化合物各处理与CK相比均明显促进了植株生长,但不同有机磷处理之间没有显著差异,在植株吸磷量上,各接种处理均为相应CK处理的2倍以上,其中磷酸二氢钾处理吸磷量最高,菌根对照植物的根外菌丝虽然被限制在有限的空间内,但其吸磷量也达到不施磷的CK-M处理的2倍多,这说明由于菌根的形成植物能利用土壤因有的有机磷来满足自身生长的需要,表3参10  相似文献   
78.
对承德市热电厂CG35/3.82-MX型循环流化术锅炉的脱硫除尘系统进行了改造,解决了原水膜除尘器效率低,烟法排放严重超标的问题,取得了良好的环境效益,社会效益和经济效益。  相似文献   
79.
Chlordecone is an organochlorine pesticide, used in the Lesser Antilles from 1972 to 1993 to fight against a banana weevil. That molecule is very persistent in the natural environment and ends up in the sea with runoff waters. The objective of the present study is to evaluate the level of contamination in several trophic groups of marine animals according to their distance from the source of pollution. Samples of suspended matter, macroalgae, herbivorous fishes, detrivorous crustaceans, zooplanktivorous fishes, first- and second-order of carnivorous fishes, and piscivorous fishes have been collected in two sites, located downstream the contaminated sites (Goyave and Petit-Bourg), in three marine habitats (coastal mangroves, seagrass beds located 1.5 km from the shoreline, and coral reefs at 3 km offshore). Animals collected in mangroves were the most contaminated (mean concentrations 193 μg kg?1 in Goyave and 213 μg kg?1 in Petit-Bourg). Samples from seagrass beds presented intermediate concentrations of chlordecone (85 μg kg?1 in Goyave and 107 μg kg?1 in Petit-Bourg). Finally, samples from coral reefs were the less contaminated (71 μg kg?1 in Goyave and 74 μg kg?1 in Petit-Bourg). Reef samples, collected 3 km offshore, were two to three times less contaminated than those collected in mangroves.  相似文献   
80.
The effectiveness of environmental protection measures is based on the early identification and diagnosis of anthropogenic pressures. Similarly, restoration actions require precise monitoring of changes in the ecological quality of ecosystems, in order to highlight their effectiveness. Monitoring the ecological quality relies on bioindicators, which are organisms revealing the pressures exerted on the environment through the composition of their communities. Their implementation, based on the morphological identification of species, is expensive because it requires time and experts in taxonomy. Recent genomic tools should provide access to reliable and high-throughput environmental monitoring by directly inferring the composition of bioindicators’ communities from their DNA (metabarcoding). The French-Swiss program SYNAQUA (INTERREG France-Switzerland 2017–2019) proposes to use and validate the tools of environmental genomic for biomonitoring and aims ultimately at their implementation in the regulatory bio-surveillance. SYNAQUA will test the metabarcoding approach focusing on two bioindicators, diatoms, and aquatic oligochaetes, which are used in freshwater biomonitoring in France and Switzerland. To go towards the renewal of current biomonitoring practices, SYNAQUA will (1) bring together different actors: scientists, environmental managers, consulting firms, and biotechnological companies, (2) apply this approach on a large scale to demonstrate its relevance, (3) propose robust and reliable tools, and (4) raise public awareness and train the various actors likely to use these new tools. Biomonitoring approaches based on such environmental genomic tools should address the European need for reliable, higher-throughput monitoring to improve the protection of aquatic environments under multiple pressures, guide their restoration, and follow their evolution.  相似文献   
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