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151.
基于奇异谱分析(singularspectrumanalysis,SSA)的基本思想,利用噪声与信号的赫斯特(Hurst)指数有显著差异这一特性,提出了一种新的SSA滤波法,同时给定了嵌入维数犔与重构阶次犘的确定标准,并将该方法应用于GPS多路径的研究中。通过模拟数据及实测GPS坐标序列的数据分析,结果表明SSA滤波法是一种有效的去噪方法,其去噪效果与小波滤波与经验模态分解(empriricalmodedecomposition,EMD)滤波相当。针对多路径效应周日重复性的特点,利用该滤波方法建立改正模型,可有效地削弱多路径效应的影响,进而提高GPS动态变形监测的精度。 相似文献
152.
本文论述了模型误差及模型参数估计的有关问题,具体包括:1)L_n范数准则;2)模型误差的一般表达式;3)线性化模型及模型含误差时的模型参数估计;4)模型的改善与优化;5)计算方案;6)模型误差与L_n范数准则。本文的论述为建立和分析各种具体的地学模型提供了必要的理论和方法。 相似文献
153.
本文根据川东地区天然气勘探开发历史,系统归纳和总结了成组气田整体勘探开发、多高点滚动勘探开发和多产层立体勘探开发三种模式的勘探程序、勘探部署以及开发特点和原则。以供后续天然气勘探开发决策时参考。 相似文献
154.
155.
Pan Ming Huang Shan-Li Wang Yu-Min Tzou Yibin Huang Boqi Weng Shunyao Zhuang Ming Kuang Wang 《Environmental Earth Sciences》2013,68(8):2199-2209
Soil is a vital biological habitat, which is of primary importance in determining and regulating biological activity and biodiversity. Therefore, it is Earth’s most important resource in sustaining both belowground and aboveground biological activities. Biodiversity versus landscape diversity and land use practices in multifunctional landscapes have been addressed. Humans have so manipulated nature that few locations in the world remain without human influence, causing unforeseen changes in ecosystem continuously and biodiversity. Among the environmental compartments, about 90 % of environmental pollutants are bound with soil particles. The soil-bound pollutants may be released to the soil solution through physical, chemical and biological interfacial interactions and pose a threat to biodiversity and ecosystem integrity. These interfacial interactions are especially important in the rhizosphere, where the kinds and concentrations of biomolecules are different from the bulk soil because of intense biological activity. These biomolecules affect biogeochemical processes, soil microbial ecology, nutrient and contaminant dynamics, abiotic and biotic factors, and soil biodiversity through allelopathic interactions. Soil interfacial interactions under different pedogenic processes and anthropogenic activity in relation to belowground biodiversity and the impact on aboveground biodiversity, productivity and integrity should be an important and exciting area of science for years to come. 相似文献
156.
Proceeding from gaining a knowledge of the structural settings in this area, the authors applied remotesensing techniques and selected multi-temporal image processing to extract information of buried structures inthe Beijing plain area. Good results have been achieved. Through an integrated analysis of remote-sensing, geo-logical, seismic and aeromagnetic data, it is pointed out that there exist two sets of buried fractures of differingtrends and orders-the northeast set and the northwest set. forming a rhombic framework in the images. Thetwo sets of fractures have still been active since the Quaternary. which is of practical signifcance for geologicalstudy, earthquake prevention and planning of urban construction in the area. The results demonstrate that theselection of multi-temporal processing of remote sensing images and the integrated analytic method are impor-tant in the study of buried structures. 相似文献
157.
Global-local interaction is an important research topic in economic geography. In recent years, the rapid development of digitalization in various countries and regions has profoundly affected the global production and trade networks. However, there is a lack of systematic theoretical discussion on digitalization and global-local interaction studies. The objective of this study is to conceptually rethink the role of digitalization in reshaping global-local interactions from a dynamic and relational perspective. To do this, the study first systematically reviewed the digital turn in economic geography and discussed the rethinking of digitalization. It is found that the understanding of digitalization is gradually moving beyond the limits of isolated, static, and passive technocentric approaches and towards a more dynamic, relational, and open perspective. Second, the study combined the digital turn with the relational turn in relational economic geography, which constructs theoretical bridges between digitalization and global-local studies. Third, this study provided a basic understanding for sorting out the evolution of the research frameworks, that is, from the global value chain (GVC) to the global production network (GPN) and then to the digital ecosystem (DE). We argued that digitalization has been deeply involved in shaping the global economic landscape, restructuring global-local production relations, and reconstructing regional development. Based on this recognition, we discussed the primary performance of digitalization on the restructuring of global-local interaction from three aspects: enterprise relationship, spatial effect and interaction mechanism. Finally, grounded in the practice of China's urban and regional digital economy development, the possible theoretical innovations and prospects for future research on digitalization and global-local interaction in the Chinese context were proposed. The study pointed out that we can integrate the regional practices of China's digital development with more in-depth research from the perspectives of the platform ecosystems, spatial effects, location analysis, local development models, and so on in future research. © 2023, Editorial office of PROGRESS IN GEOGRAPHY. All rights reserved. 相似文献
158.
利用信息熵、灰色关联等分析方法对岳阳市2009—2015年土地利用结构信息熵变化规律、土地利用绩效指数以及它们之间的内在联系进行系统分析。结果表明:1时间上,岳阳市土地利用结构信息熵持续增长,土地利用变化主要表现为城镇村及工矿用地、交通运输用地、耕地的大幅增加以及园地、林地、水域及水利设施用地等地类的减少;2空间上,岳阳市各地区信息熵存在较大差异,中心城区信息熵明显高于其他区域,且经济发展水平与信息熵值呈正相关;3岳阳市土地利用绩效指数逐年上升,其中经济绩效对综合绩效的带动作用最明显,公平绩效则相对滞后;4与土地利用绩效相关性最显著的是城镇村及工矿用地、交通运输用地,但关联系数都较低。 相似文献
159.
从岩心、薄片等实际资料着手,结合EMI成像测井等现代技术研究,认为新疆克拉玛依油田八区上二叠统下乌尔禾组属河控型扇三角洲相沉积,并识别出两种亚相和9种微相:2种亚相是扇三角洲平原和扇三角洲前缘亚相,而前扇三角洲不发育。9种微相是辫状河道沉积、漫流沉积、泥石流沉积、筛滤沉积、水下分流河道沉积、水下分流河道间沉积、水下天然堤沉积、碎屑流沉积及颗粒流沉积。同时,以成像测井资料为主要依据,结合岩石粒度及成分特征分析,表明研究区下乌尔禾组5个时期的物源方向不尽一致,表现为从早到晚,由第5亚期至第1亚期,物源方向由以西南方向为主,逐渐变为以西北为主。与物源变化相对应,沉积相也呈现有规律的变化。本文在对沉积相进行详尽研究的基础上,深入解剖了克拉玛依油田上二叠统下乌尔禾组的沉积微相特征,阐明了沉积相的展布和演化。 相似文献
160.
In this paper the stochastic Green function method is used to solve random wave equation of the electromagnetic field. The volume scattering coefficient formula of the sea surface containing bubbles is given. It is also point out that when the incident angle of the electromagnetic wave is less than 30°, the surface scattering model is not sufficient. The joint problem of the volume scattering and the surface scattering coefficient in the neighbourhood of incident angle 30° is discussed. 相似文献