共查询到20条相似文献，搜索用时 656 毫秒
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Effects of galvanic distortion on magnetotelluric data over a three-dimensional regional structure 总被引：2，自引：0，他引：2
Although the galvanic distortion due to local, near-surface inhomogeneities is frequency-independent, its effect on the magnetotelluric data becomes, in a 3-D structure, frequency-dependent. Therefore, both the apparent resistivity and the phase responses are disturbed, and a correction should be carried out prior to the 3-D interpretation in order to retrieve the 3-D regional impedance tensor. In many cases, the structure is 2-D for depths corresponding to a first range of periods and 3-D for longer periods (called 2-D/3-D). For these cases, a simple method which allows us to retrieve the 3-D regional impedance tensor (except the static shift) is presented. The method proposed uses the Groom & Bailey decomposition of the distortion matrix for the short periods. Three examples are presented: two using synthetic data and one employing real data. These examples show the effect of the galvanic distortion over a regional 2-D/3-D model and the retrieval of the regional transfer functions from the distorted ones. 相似文献
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Inversion for regional 2-D resistivity structure in the presence of galvanic scatterers 总被引：2，自引：0，他引：2
C. deGroot-Hedlin 《Geophysical Journal International》1995,122(3):877-888
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A quantitative methodology to extract regional magnetotelluric impedances and determine the dimension of the conductivity structure 总被引：1，自引：0，他引：1
R. W. Groom R. D. Kurtz A. G. Jones D. E. Boerner 《Geophysical Journal International》1993,115(3):1095-1118
A methodology to determine quantitatively the dimensionality of the dominant conducting structures and the resolution of the structural parameters in magnetotelluric data is presented. In addition, the method recovers the regional impedance responses when the regional structure can be characterized, at least approximately, as 1- or 2-D. The methodology is based upon three general models of the MT tensor, each of which has a distinct parameterization and physical interpretation. A weighted statistical residual describes quantitatively the fit of the model response to the data within the scatter of the measured data and hence permits: (1) tests of dimensionality, (2) determination of the appropriate strike angle, and (3) recovery of the regional responses.
The method has been tested extensively with synthetic data and proven to be successful. These synthetic studies give insight into the different physical parameterizations and the stability of the parameters determined. We describe and illustrate some of these synthetic studies. With field data, the methodology is not always as straightforward, but its application to a great many sites has proven valuable. Data from two closely spaced sites, which are both affected by strong but very different 3-D effects, are analysed to illustrate the geological significance of the results. The analyses reveal and recover regional responses within the data which indicate the presence of electrical anisotropy located deep in the crust and upper mantle. Analyses of the entire data set, of which these two form a part, confirm this finding. 相似文献
The method has been tested extensively with synthetic data and proven to be successful. These synthetic studies give insight into the different physical parameterizations and the stability of the parameters determined. We describe and illustrate some of these synthetic studies. With field data, the methodology is not always as straightforward, but its application to a great many sites has proven valuable. Data from two closely spaced sites, which are both affected by strong but very different 3-D effects, are analysed to illustrate the geological significance of the results. The analyses reveal and recover regional responses within the data which indicate the presence of electrical anisotropy located deep in the crust and upper mantle. Analyses of the entire data set, of which these two form a part, confirm this finding. 相似文献
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Malcolm R. Ingham 《Geophysical Journal International》1988,92(1):165-169
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Summary. A new method of calculating magneto-telluric surface impedances in terms of a layered anisotropic model is developed by considering reflections from the interface between two anisotropic layers. An algorithm for propagating impedances from one layer boundary to the next is given. The method is rapid and uses a simple representation of the layer parameters. 相似文献
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Zhang ShulinDepartment of Geography Chongqing Teachers College Chongqing CHINA 《地理学报(英文版)》1998,(1)
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中国区域经济时空动态不平衡发展分析 总被引：42，自引：7，他引：35
区域经济发展是受区域内外的多重因素影响的 ,对区域经济发展的空间不平衡动态规律的研究是国内外学者研究的重要课题。本文应用区域经济空间动态发展模型对中国 1978～ 1998年的区域经济生产率增长率进行分析 ,寻找影响其增长的区域内外因素及变动规律。考虑到中国的本土化特色 ,在模型中引入开放优惠政策和区位优势变量 ,回归结果得到显著提高。研究表明 ,在过去的 2 0年间中国区域经济发展与国外 (如欧盟 )的发展规律不完全相同 ,具有中国特色。尽管各地区间的经济发展存在差异 ,但总体上中国经济发展满足一定的模式。 相似文献
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随着经济发展和人口的增加,环境与资源问题在中东国家日益普遍和突出。环境问题的根源及其影响超越了国界,环境问题也必须国际合作才能解决,这对以色列所在的东地中海地区特别重要。东地中海国家开展环境治理和管理的合作不但符合该地区社会经济的可持续发展要求,也是促进和巩固中东政治和平的重要手段。本文分析了以色列政府1996年1月提出的《区域环境合作和发展选择》文件的基本框架和内容,指出：这个规划对区域经济合作具有宏观指导意义和操作意义,更是新时期以色列抢占中东经济高地的一个前瞻性战略,将对中东的政治经济新格局产生深远的影响。 相似文献
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从行政及区位条件、经济基础、基础设施、科研实力、社会服务、资源禀赋、环境状况、市场容量 8大要素 4 8个方面对四川省 2 1个地级区域的投资环境进行综合评价 ,阐述该区域投资环境的区域差异规律及存在的问题和对策。 相似文献
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Understanding telluric distortion matrices 总被引：9，自引：1，他引：9
J. Torquil Smith 《Geophysical Journal International》1995,122(1):219-226
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The blockage of the L g wave by crustal barriers such as continental margins and graben structures has long been recognized as providing a very useful tool for mapping large-scale lateral crustal variations along the propagation path. Numerical simulation of L g -wave propagation in complex anelastic media using the pseudospectral method provides insight into the nature of the propagation process using both snapshots of the wavefield and synthetic seismograms. A variety of 2-D structures have been investigated, including the influence of sediments, crustal thickness and attenuation.
Thick sedimentary basins covering a graben structure can have a major influence, since they remove L g energy by generating P conversion and scattering–the principal mechanisms for strong L g attenuation across a graben. The reduction of the L g energy is reinforced by anelastic attenuation in the sediments as well as the influence of the gradually thinning crustal waveguide associated with an elevated Moho.
The extinction of L g in a sequence of explosions fired across the central graben of the North Sea can be simulated by numerical calculations for the structure derived from refraction experiments. 相似文献
Thick sedimentary basins covering a graben structure can have a major influence, since they remove L
The extinction of L
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区域开放与区域保护是两个相悖的命题，在当今对外开放日渐深入之时，区际分工与开放也已成为我国区域经济发展的一个主题。根据传统比较优势理论，区域分工会给各区域带来利益增进，但是，若考虑到市场需求因素和国内价格扭曲现象的存在，分工对有的区域带来利益增进，而对有的区域带来利益损失。所以在开放的主旋律中，有的区域会倾向于实施区域保护政策，以防止利益损失。但保护只是区域发展的阶段性政策，长期来看。区域开放是一个必然的趋势。 相似文献
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粤港澳区域文化综合体形成刍议 总被引：6，自引：0，他引：6
区域文化综合体作为文化存在的一种空间形式,由文化景观结构、文化区域结构和文化中心等有机结合而成。本文根据文化梯度概念,运用文化空间演化的原理和方法,在分析粤港澳文化形成的地缘、史缘、族缘关系及其文化作用的基础上,阐述珠江三角洲广府文化核心区、香港区域文化、澳门区域文化形成的历史演变过程及各自特质和风格,通过三地长期文化互动,包括城市建筑、风俗、语言、文学艺术、思想、宗教、价值观念等文化要素不断交流、碰撞和创新,形成以中西文化交融和三地空间有机结合,穗港澳三个文化中心并立为特征的区域文化综合体。 相似文献
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区域政策的调控效应分析——以我国财政转移支付制度为例 总被引：5，自引：0，他引：5
论文通过财政转移支付制度的案例研究,分析了我国区域政策的调控效应。认为现行财政转移支付制度虽存在不足,但对调控区域经济仍然发挥了积极作用。首先,财政转移支付很大程度上缓解了欠发达地区的财政困难。其次,财政转移支付与大多数地区经济增长的相关性较强。目前欠发达地区财政转移支付对地区经济增长的带动作用低于发达地区,与各区域所处的经济发展阶段和资金投向有关。第三,财政转移支付对欠发达地区城镇居民收入的提高起到了较大的作用 相似文献