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91.
92.
通化中生代断陷盆地以频繁的沉积作用和火山作用为特征,形成了多旋回的火山沉积序列,表现为火山爆发相,溢流相与冲积扇相, 湖泊相的反复交替,并发育了湖相火山碎屑浊积岩系。盆地演化经历了早期非补偿阶段,早期熔浆充填期,火山喷发期后非补偿沉积阶段,晚期熔浆充填期,构成二个大的火山-沉积旋迥。 相似文献
93.
砂砾岩储集体为快速沉积环境下形成的沉积物,具有很强的非均质性,因此,利用测井数据进行岩性识别的结果准确性较差。笔者针对该问题,从砂砾岩储集体中岩性测井特征提取和模式识别算法2方面进行分析。在测井特征提取上,针对其粒度跨度大、成分复杂、过渡岩性测井特征多样的特点,利用沉积相、物源体系控制岩石的成分和结构特征的多样性,达到准确提取岩石骨架颗粒参数的目的。在模式识别算法上,选取支持向量机、极限学习机和概率神经网络3种基于不同分类原理的模式识别算法,构建SEP岩性判别算法。在松辽盆地南部梨树断陷下白垩统营城组砂砾岩储集体岩性识别中,采用SEP法,利用GR-AC-CNL-DEN-RLLD-w(K-PE测井数据组合,对13口钻井的284块样本岩性进行判别,SEP识别结果与3种单方法相比,能够提高岩性判别结果的准确性和稳定性,识别符合率均值达到83.64%。 相似文献
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Natural attenuation of septic system nitrogen by anammox 总被引:1,自引:0,他引:1
Robertson WD Moore TA Spoelstra J Li L Elgood RJ Clark ID Schiff SL Aravena R Neufeld JD 《Ground water》2012,50(4):541-553
On-site disposal of sewage in septic systems can lead to groundwater plumes with NO(3)(-)-N concentrations exceeding the common drinking water limit of 10 mg/L. Currently, denitrification is considered as the principal natural attenuation process. However, at a large seasonal-use septic system in Ontario (256 campsites), a suboxic zone exists where nitrogen removal of up to 80% occurs including removal of NH(4)(+)-N. This zone has both NO(3)(-)-N and NH(4)(+)-N at >5 mg/L each. In the distal NH(4)(+)-rich zone, NH(4)(+)-N concentrations (8.1 ± 8.0 mg/L) are lower than in the proximal zone (48 ± 36 mg/L) and NH(4)(+)-N is isotopically enriched (concentration-weighted mean δ(15)N of +15.7‰) compared to the proximal zone (+7.8‰). Furthermore, δ(15)N-NH(4)(+) isotopic enrichment increases with depth in the distal zone, which is opposite to what would result if nitrification along the water table zone was the mechanism causing NH(4)(+) depletion. Bacterial community composition was assessed with molecular (DNA-based) analysis and demonstrated that groundwater bacterial populations were predominantly composed of bacteria from two Candidatus genera of the Planctomycetales (Brocadia and Jettenia). Together, these data provide strong evidence that anaerobic ammonium oxidation (anammox) plays an important role in nitrogen attenuation at this site. 相似文献
96.
井间断裂构造分析是根据测井资料,以地层分层数据为基础,利用计算机技术实现井间断裂分析的一种计算机自动分析方法.动态波形匹配算法能够很好地建立井间地层之间的对比关系,可以通过曲线拟合、特征提取、匹配代价计算等步骤,自动绘制井间地层对比的路径图解.通过对各种构造的路径图分析,总结出正断层、逆断层、不整合、同沉积断层、犁式断层和地层尖灭等34种情况下的路径图模式,提出路径图模式及相关概念. 相似文献
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98.
The environmental threat from oil spills remains significant across the globe and particularly in regions of high oil production and transport such as the Gulf. The ultimate damage caused can be limited by mitigation actions that responders deploy. The responsible and appropriate use of oil spill treatment products (e.g. dispersants, sorbents etc.) can offer response options that can result in substantial net environmental benefit. However, the approval and choice of what products to use needs careful consideration. The United Kingdom has had in place a statutory approval scheme for oil spill treatment products for 30 years. It is based on measures of efficiency and environmental acceptability. Two toxicity tests form an integral part of the assessment, the Sea test and the Rocky Shore test, and work on the premise that approved products will not make the situation significantly worse when added to spilled oil. This paper outlines the UK approach and how its rationale might be applied to the approval of products specific for the Gulf region. Issues such as species choice, higher temperatures and salinity and regional environmental conditions are considered. 相似文献
99.
Several biotic indices have been proposed for the assessment of the ecological status of benthic macroinvertebrates in marine waters, although none have been generally accepted. When it comes to assessing highly stressed natural environments, such as estuaries, the controversy and uncertainty is much higher than for any given normal index. In this article, we test the behavior and suitability of different biotic indices proposed under the perspective of the Water Framework Directive (S, H, AMBI, M-AMBI, BQI, W-statistic, Taxonomic distinctness) for the assessment of estuaries in northern Spain. The low species richness and dominance of a few tolerant species in the characteristic community of these estuaries presented a challenge to the application of the biotic indices tested. Combined approaches that integrate different aspects of water quality and ecosystem functionality could increase the reliability of the ecological assessment of these transitional waters. 相似文献
100.
笔者针对黄骅坳陷孔南地区古地理格局认识上存在的问题,通过沉积相分析和古地理格局恢复,证实孔店凸起-孔店构造带是从孔一段沉积早期开始发育的,在孔一段沉积晚期形成其雏形;孔二段沉积时期孔南地区为拗陷盆地。孔一段沉积时期,整个孔南地区都处于沉降阶段,而孔店凸起-孔店构造带则是一个沉降相对缓慢的地带,在地形上并不是相对隆起区。 相似文献