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1.
In the present study, a methodology for reliability assessment of slack and taut mooring systems against instability has been presented. For this purpose, first, stability analysis of slack and taut mooring systems has been carried out and instable regions are obtained using procedure available in the literature. Having known the instable region(s), methodology for reliability assessment has been proposed which is based on Monte Carlo Simulation technique. After using the proposed methodology, probabilities of failure and reliability indices has been obtained for the above systems. Some parametric studies, such as, effect of lower and upper limits of instability and effect of frequency range of generations are also included to obtain the results of practical interest. 相似文献
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Nagpal Anushree Hassan Mohammad Siddiqui Masood Ahsan Tajdar Atiqua Hashim Mohammad Singh Abhra Gaur Suman 《GeoJournal》2021,86(2):649-661
GeoJournal - Sanitation is a multidimensional concept alluding primarily to provision of services for safe disposal of human excreta, provision of clean potable water as well as maintenance of... 相似文献
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随着新能源产业的快速发展, 全球碳酸锂贸易量逐渐增长, 但其出口集中于少数国家, 这意味着全球碳酸锂供应存在一定的风险。为了深入了解全球碳酸锂贸易格局演变、供应危机传播路径及影响, 本文构建了2000—2021年全球碳酸锂贸易网络和级联失效模型, 概述了主要出口国贸易流向和贸易格局演变过程, 并模拟了不同供应危机来源的雪崩规模、传播路径及其影响。我们得到: (1)20多年来全球碳酸锂贸易集中度逐渐增加, 出口前三位国家保持稳定, 而主要进口大国变化明显, 贸易格局已由南美供应全球转变为南美供应东亚; (2)碳酸锂贸易供应危机的影响范围逐渐扩大, 间接传播逐渐占据主导地位; (3)智利供应危机对中日韩的影响程度逐渐扩大, 但对欧洲的影响时间最长; 阿根廷和中国的雪崩规模在上升、传播次数增加, 而美国则相反。本文将贸易格局演变与危机传播结合, 明确了全球碳酸锂主要贸易国智利、阿根廷、中国、德国等作为供应危机来源的影响程度及其传播路径。以上分析结果将有利于维护全球碳酸锂贸易稳定和主要贸易国采取应对策略缓解供应危机。 相似文献
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基于对子午链台站地震地磁前兆异常以及地球空间环境变化等研究方向的需求分析,利用网络、大数据、云计算等新技术,结合地震数据专家(DatistEQ)软件,设计子午链台站地磁指数报告自动产出系统。该系统通过低代码、敏捷式开发工作流程,连接不同功能节点,可以实现用户定制化、数据标准化、功能智能化的系统报告产出。通过本地或者云端一键流程化工作,将不同类型的数据发送到科研工作者或其他需求者,简化工作流程,优化数据处理,实现高效率产品产出。 相似文献
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Numair A.Siddiqui Mu.Ramkumar Abdul Hadi A.Rahman Manoj J.Mathew M.Santosh Chow W.Sum David Menier 《地学前缘(英文版)》2019,10(3):957-971
Advances in photogrammetry have eased the acquisition of high-resolution digital information from outcrops, enabling faster, non-destructive data capturing and improved reservoir modeling. Geocellular models for flow dynamics with in the virtual outcrop in siliciclastic deposits at different sets of sandstone facies architecture remain, however, a challenge. Digital maps of bedding, lithological contrast, spatial-temporal variations of bedding and permeability characteristics make it more easy to understand flow tortuosity in a particular architecture. An ability to precisely model these properties can improve reservoir characterization and flow modeling at different scales. Here we demonstrate the construction of realistic 2 D sandstone facies based models for a pragmatic simulation of flow dynamics using a combination of digital point clouds dataset acquired from LiDAR and field investigation of the Sandakan Formation, Sabah, Borneo.Additionally, we present methods for enhancing the accuracy of outcrop digital datasets for producing high resolution flow simulation. A well-exposed outcrop from the Sandakan Formation, Sabah, northwest Borneo having a lateral extent of 750 m was chosen in order to implement our research approach. Sandstone facies and its connectivity are well constrained by outcrop observations, data from air-permeability measurements, bilinear interpolation of permeability, grid construction and water vector analysis for flow dynamics.These proportions were then enumerated in terms of static digital outcrop model(DOM) and facies model based on sandstone facies bedding characteristics. Flow simulation of water vector analysis through each of the four sandstone facies types show persistent spatial correlation of permeability that align with either cross-bedded orientation or straight with more dispersion high quality sandstone(porosity 21.25%-41.2%and permeability 1265.20-5986.25 mD) and moderate quality sandstone(porosity 10.44%-28.75% and permeability 21.44-1023.33 mD). Whereas, in more heterolithic sandstone(wavy-to flaser-bedded and bioturbated sandstone), lateral variations in permeability show spatially non-correlated patterns over centimeters to tens of meters with mostly of low quality sandstone(porosity 3.4%-12.31% and permeability < 1 mD to 3.21 mD). These variations reflect the lateral juxtaposition in flow dynamics. It has also been resulted that the vertical connectivity and heterogeneities in terms of flow are mostly pragmatic due to the interconnected sandstone rather than the quality of sandstone. 相似文献
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TritonX-100-5-Br-PADAP光度法测定铜和镍 总被引:2,自引:0,他引:2
研究了非离子型表面活性剂Triton X- 100 存在下,用5 - Br - PADAP 光度法测定铜、镍的方法。结果表明:在pH9 .0 的硼砂缓冲介质中,5 - Br - PADAP 与铜和镍生成紫红色络合物,λCum ax = 575 nm ,εCu = 1 .04 ×105 L·mol- 1·cm - 1 ;λNim ax = 575 nm ,εNi = 1 .14 ×105 L·mol- 1·cm - 1 。铜和镍的质量浓度分别在0 ~560 μg/ L和0 ~440 μg/ L符合比尔定律。加入六偏磷酸钠后,由于偏磷酸镍的形成,镍不再与5 - Br - PADAP 显色,可通过铜及铜镍总量的测定,计算出镍的含量。用该方法实测了钢样中铜和镍的含量,结果与推荐值相符,对铜和镍5 次测定的RSD均小于5 % 。 相似文献
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Geomagnetism and Aeronomy - Ionospheric anomaly crest regions are most challenging for scientific community to understand its mechanism and investigation, for this purpose we are investigating some... 相似文献
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Crustal deformation shows different patterns at different depths due to changes in the physical properties of rock.Tectonic levels can be defined based on the geometry and deformation mechanisms of crustal deformation patterns. Nujiang Gorge, with a high riverbed drop, great erosion depth, and strong deformation, has rock exposures at different tectonic levels and thus provides an ideal lab for deformation study. This paper takes the Nujiang Gorge from Chawalong to Fugong as the object to identify structural deformation patterns at different depths through field study and deformation analysis. At depth, the primary form of deformation is flow deformation, as shown on the outcrops at Maji. Ductile shear deformation can be found in many outcrops within the study region, e.g., the Gaoligong dextral shear zone and Puladi-Songta sinistral shear zone that lie to the south and north of Maji, respectively. Further to the north of Puladi, the dominated deformation pattern is similar fold and dense sub-vertical foliation. In addition, brittle faults, as evidence of shallow deformation, can be seen overprinting on the deeper deformation features all over the region. Based on those observations, this paper identifies four tectonic levels from depth to the surface: flow deformation, ductile shear deformation, similar fold, and brittle fault deformation, all of which result from the NEE-SWW compressive stress field. Further evidence from studies on the region′s thermal evolution and regional tectonics suggests that the development of different tectonic levels is closely linked to the discrepant uplift or denudation since the Miocene(~21 Ma). 相似文献