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681.
682.
针对现有辫状河储层构型单元定量表征方法关键参数获取困难且可靠性存疑的问题,以储层构型理论为指导,基于现代辫状河沉积、钻井岩心、录井和测井等资料,提出了基于单一辫状河道宽度的构型单元定量表征方法。首先,根据单井构型单元解释结果,确定同期辫状河道平面分布;其次,根据连井对比剖面,确定连井剖面内单一辫状河道间的界线位置;再次,根据现代辫状河单一辫状河道宽度与构型单元关系定量模型,限定辫状水道宽度、复合心滩长度及宽度等4级构型单元规模;最后,在单一辫状河道内确定4级构型单元平面分布,进而在密集井网区对复合心滩进行解剖,确定单个心滩位置和几何形态。采用该方法对苏××提高采收率试验区盒8下1-3单层辫状河致密砂岩气藏进行了分析,结果表明:该单层砂岩气藏发育5条单一辫状河道,其宽度为1 050~1 890 m;辫状水道宽度为234~435 m;复合心滩长度和宽度分别为1 931~3 569 m、685~1 242 m;单个心滩长度和宽度分别为660~1 880 m、310~1 030 m。 相似文献
683.
笔者在鄂尔多斯盆地上三叠统延长组长8段的岩芯中首次识别出液化柱变形构造,本文从三维空间研究其宏观与微观特征。赋存液化柱的长8段的多个层位的岩芯中均发现有软沉积物变形构造,如液化流动变形、水塑性变形及脆性变形等,广泛分布于盆地不同地区的钻井岩芯中,并在垂向上重复出现。结合长8段的沉积环境和构造背景分析,笔者认为长8段的液化柱与软沉积物变形系地震触发。晚三叠世鄂尔多斯盆地以南秦岭地震造山运动与盆地沉陷是长8段软沉积物变形的构造背景。根据地震触发软沉积物变形构造的时空分布,鄂尔多斯盆地在长8段沉积的地质时期已受控于秦岭造山带动力机制的控制,而不是传统认为的仅在长8段沉积末期。 相似文献
684.
《Geoforum》2017
The most prominent ‘victim’ of the global financial crisis in 2007/2008 has been Greece, which is, even now, in the middle of an economic and social storm that is threatening its economic and social cohesion and its membership of the Eurozone. Using the social well-being conceptual framework as a benchmark and exploiting the literature of composite indicators, the paper aims to assess and measure the regional impact of the crisis in a systematic and comprehensive way. Differing from most of previous studies, both at national and international levels, this study is based on the assumption that the effects of the crisis go far beyond economics and create a social crisis strongly associated with significant human and social costs that might transform Greece’s regional status and threaten its regional well-being, probably in a very unequal way. The main finding of the analysis is that although all regions were severely affected by the dynamics and intensity of the crisis, some regions were more affected than others, leading to ‘winners’ and ‘losers’. From a policy point of view, the results of this study have serious implications for crisis management, recovery policy actions and a country’s social cohesion, especially in Greece where austerity policy measures not only imposed considerable cutbacks in regional development policies but also ignored the spatial dimension of the crisis. 相似文献
685.
Data on abundance and isotopic composition of porewater and sedimentary sulfur species are reported for relatively uncontaminated and highly contaminated fine-grained anoxic sediments of St. Andrew Bay, Florida. A strong contrast in amount and composition of sedimentary organic matter at the two sites allows a comparative study of the historical effects of increased organic loading on sulfur cycling and sulfur isotopic fractionation. In the contaminated sediments, an increase in organic loading caused increased sedimentary carbon/sulfur ratios and resulted in higher rates of bacterial sulfate reduction, but a lower efficiency of sulfide oxidation. These differences are well reflected in the isotopic composition of dissolved sulfate, sulfide, and sedimentary pyrite. Concentration and isotopic profiles of dissolved sulfate, organic carbon, and total sulfur suggest that the anaerobic decomposition of organic matter is most active in the upper 8cm but proceeds at very slow rates below this depth. The rapid formation of more than 90% of pyrite in the uppermost 2 cm which corresponds to about 3 years of sediment deposition allows the use of pyrite isotopic composition for tracing changing diagenetic conditions. Sediment profiles of the sulfur isotopic composition of pyrite reflect present-day higher rates of bacterial sulfate reduction and lower rates of sulfide oxidation, and record a profound change in the diagenetic cycling of sulfur in the contaminated sediments coincident with urban and industrial development of the St. Andrew Bay area. 相似文献
686.
687.
Mesopelagic fish,the most important daily vertically migrating community in the oceans,are characterized by high lipid content which may obscure the interpretation of stable isotopes analysis.Demersal fish,which are important consumers in the food web dominated by mesopelagic fish,also have a high lipid content.Here we collected 127 fish samples from the South China Sea and evaluated the effect of lipid contents on δ13C of mesopelagic and demersal fish.In lipid-extracted mesopelagic f... 相似文献
688.
由于海水盐度大、有机质含量低,从海水中提取和纯化克级溶解性有机质(dissolved organic matter,DOM)一直十分困难。基于Bond Elut PPL固相萃取小柱法进行海水DOM固体样品提取的放大试验,建立DOM自动化调酸、PPL树脂吸附技术,最后形成提纯、冷冻干燥PPL-DOM(通过PPL树脂提取的DOM)完整工艺。采用元素分析、三维荧光光谱、红外光谱和固态13C核磁共振(NMR)波谱法进行样品表征。结果表明:(1)该方法对近海表层海水DOM回收率稳定在50%以上,搭建的提取装置DOM日吸附量可达230mg;(2)鳌山湾四个季节批次PPL-DOM整体分析结果表明,样品的元素组成和光谱特征相似,表明方法适用性和稳定性较好;(3)三种水生态环境的PPL-DOM13C NMR谱图显示样品的基本特征相似,以烷基碳、碳水化合物碳、芳香碳和羧基碳/酰胺碳为主,其中偶极去相(dipolar dephasing)谱显示了DOM前体化合物来源的差异。多种结果表明放大后的PPL固相萃取法可稳定提取克级DOM样品。 相似文献
689.
690.
A new seasonal and annual dataset describing Arctic sea ice extents for 1901–2015 was constructed by individually re-calibrating sea ice data sources from the three Arctic regions (North American, Nordic and Siberian) using the corresponding surface air temperature trends for the pre-satellite era (1901–1978), so that the strong relationship between seasonal sea ice extent and surface air temperature observed for the satellite era (1979-present) also applies to the pre-satellite era. According to this new dataset, the recent period of Arctic sea ice retreat since the 1970s followed a period of sea ice growth after the mid-1940s, which in turn followed a period of sea ice retreat after the 1910s. Arctic sea ice is a key component of the Arctic hydrological cycle, through both its freshwater storage role and its influence on oceanic and atmospheric circulation. Therefore, these new insights have significance for our understanding of Arctic hydrology.
EDITOR D. KoutsoyiannisASSOCIATE EDITOR not assigned 相似文献