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81.
82.
目前很多文献基于弹性力学假设,以小形变、均匀应变场为前提,利用GPS资料建立了中国大陆块体的整体旋转与均匀应变模型,并对模型进行了相关检验.但上述对模型的检验侧重从模型的拟合效果上进行分析和比较,忽略了对模型的适用性和假设条件合理性的检验.实际上,不同块体由于自身构造和外部条件的不同,其运动状况与应变状态并不完全一致,模型的适用性需进一步的验证.本文提出了两步检验方法对所建立的模型在中国大陆6个主要块体上进行了检验:第一步对应变参数进行显著性检验,第二步对应变均匀性进行检验,结果表明:根据所用数据精度,华南块体的刚性程度在95% 的置信水平上可以认为显著的,建立模型时不必考虑内部形变;其他块体内部形变显著,整体旋转与均匀应变模型并不能反映真实的地壳运动状态,必须考虑其形变的不均匀性. 相似文献
83.
There are two basic requirements for heavy-oil recovery processes: first, mobilize the bitumen, and second, have a drive mechanism
deliver the mobilized bitumen to a production wellbore. In situ combustion has the potential to be an important heavy-oil
recovery method. Before design of in situ combustion recovery processes can start, it is necessary as a first step to understand
the kinetics of various complex chemical reactions and determine kinetic constants associated with the reactions. Even with
modern reservoir simulation capabilities, this is a significant challenge. In this research, an Athabasca bitumen combustion
tube experiment, conducted by the ISC Research Group at the University of Calgary, was history matched by using a reservoir
thermal simulator to determine a set of kinetic parameters as well as the transport parameters for the system. The main results
of the history match was a match of air injection rate, bitumen and gas production volumes, average product gas compositions,
temperature profiles along the tube through time, and pressure. Gridding sensitivities were examined to determine if the derived
kinetic and transport parameters were dependent on gridblock size. The results revealed that the grid was refined enough to
sufficiently capture thermal, mass transfer, and reaction length scales. After this single match was achieved, the same constants
were used to successfully predict several other combustion tube experiments. The results suggest that the fuel (coke) for
high-temperature oxidation (HTO) originates mainly from low-temperature oxidation (LTO) and not from thermal cracking. This
implies that the major control on HTO is upstream oxygen transfer into the LTO region. If LTO does not occur, then a relatively
small amount of coke is deposited in the matrix due to thermal cracking and this may be insufficient to start or sustain HTO. 相似文献
84.
P. Yunus Ali 《Marine Geodesy》2013,36(1):26-39
The tsunami waves generated during the Sumatra-Andaman earthquake of 26 December 2004 devastated the coastal area along Trinkat Island, causing sudden changes to the morphology of the landforms. This study uses a series of satellite images to record the short-term morphological response and shoreline changes as well as the recovery of coastal land after its destruction. Results indicate that the island experienced substantial erosion and a significant reduction in land area. Shoreline erosion is more prevalent than accretion at an average linear regression rate of ~?9 m per year between 2004 and 2013. The major morphological changes at Trinkat Island were observed in coastal inlets, beaches, and bay head-lands. Straight beaches had almost recovered eight years after the tsunami; however, erosion is continually observed in other areas. Our study will help understanding the response and recovery of shorelines in Indian Ocean regions after the 2004 tsunami. 相似文献
85.
土地质量地球化学调查计划是我国继区域化探全国扫面计划之后一个新的国家地球化学填图计划,该计划实施20年来,在支撑土壤环境污染防控、土地资源管理、国家重大立法、精准扶贫等方面做出了重大贡献,显著拓展了地质工作服务链。本文从计划的提出背景、项目的组织实施、主要进展、调查技术的进步和分析测试技术的提高与质量控制方案的完善等方面回顾了该计划的发展历程。从全国耕地地球化学状况、全国省会城市土壤环境质量状况、中国主要淡水湖泊沉积物环境质量状况、中国主要农耕区20年来土壤碳库变化4个方面对调查成果做了全面总结。全方位介绍了调查应用成果在土地管理、土壤污染防治、农业种植结构调整、脱贫攻坚、地方病防治、油气勘查、固体矿产勘查等7个领域中的应用。并在调查技术革新、评价方法创新和调查与研究融合三个方面对土地质量地球化学调查工作的未来发展趋势做了展望。 相似文献
86.
87.
Due to energy shortage and increasing environmental awareness, resources in shallow underground space have been rapidly exploited and utilized. So that studying variation characteristics of geothermal response in gneiss is necessary for effective and rational use of underground heat. Based on field test of thermal response in gneiss under hydrogeological survey project carried out in shallow geothermal energy development zone in Liaoning Province, this thesis analyzes mathematical statistics of geothermal response characteristics in main gneiss of Laoning Province. The initial formation temperature ranges from 10.80℃ to 15.80℃ according to field test. The statistical results show that in the condition of natural water content, the average thermal conductivity of Quaternary loose rocks comes as clay silty silty fine sand medium sand coarse sand gravelly sand. This order is consistent with thermal conductivity characteristics of gneiss obtained in the laboratory. Formation temperature recovery in different strata follows as granite medium sand clay. This order is opposite to the absolute value of temperature recovery curve slope of corresponding lithology, which shows that the stratum with higher temperature recovery rate has lower temperature recovery curve slope. 相似文献
88.
Many fish stocks in the world are depleted as a result of overexploitation, which reduces stock productivity and results in loss of potential yields. In this study we analyzed the catch trends and approximate thresholds of sustainable fishing for fished stocks to estimate the potential loss of catch and revenue of global fisheries as a result of overexploitation during the period of 1950–2010 in 14 FAO fishing areas. About 35% of stocks in the global marine ocean have or had suffered from overexploitation at present. The global catch losses amounted to 332.8 million tonnes over 1950–2010, resulting in a direct economic loss of US$298.9 billion(constant 2005 US$).Unsustainable fishing caused substantial potential losses worldwide, especially in the northern hemisphere.Estimated potential losses due to overfishing for different groups of resources showed that the low-value but abundant small-medium pelagics made the largest contribution to the global catch loss, with a weight of 265.0 million tonnes. The geographic expansion of overfishing not only showed serial depletion of world's fishery resources, but also reflected how recent trends towards sustainability can stabilize or reverse catch losses.Reduction of global fishing capacity and changes in fishery management systems are necessary if the long-term sustainability of marine fisheries in the world is to be achieved. 相似文献
89.
本文以辽河西部凹陷某试验区为例,基于7 口井岩心、镜下薄片、分析测试及400口井测井等多种资料,采取点、线、面相结合的研究思路,利用地质统计学方法,开展稠油热采储层非均质性研究。整体上,于楼油层储层非均质性较强,储层非均质性受沉积作用、成岩作用和构造作用等影响(以沉积作用为主)。单井岩电特征与层内韵律非均质性关系密切,目的层可见3种沉积韵律模式,包括正韵律、反韵律和复合韵律(其中以正韵律和复合韵律为主)。沉积微相空间上的快速变化,导致储层非均质性增强。单层之间隔层分布较稳定,隔层厚度多大于2 m。非均质性强、中、弱的区域大体呈条带状,以北西-南东向展布,与物源方向基本一致。储层非均质性直接影响到了油藏的开发效果,研究储层非均质性可为油藏开发方式的转换提供参考。 相似文献
90.
This paper provides insights into the dynamic linkages between the ongoing construction of houses for people displaced by war and disaster, conceptions of homemaking and processes of recovery and reconstruction in the post‐tsunami context in Sri Lanka. In so doing, it also uncovers the dilemmas and ambiguities that are embedded in the recovery process. A case from Eastern Province, Sri Lanka illustrates how recovery works in local areas are driven by various stakeholders from outside, whose negotiations and power, voices and preferences, both independently and collectively, define the scope for homemaking processes. Our findings recommend that debates of ‘building back better’ following such disasters should embody an understanding of houses as political, cultural, social and economic constructs, and be cognizant of the wider processes of homemaking. 相似文献