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121.
首先,从空间认知语言学的角度研究了空间关系自然语言描述中谓词、量词等的分类方法;然后,在分析空间查询语言特点的基础上建立了自然语言空间查询的4类句法模式;最后,设计了一个基于自然语言空间关系的空间查询系统框架,并进行了初步实现。  相似文献   
122.
The growth of intensive export-oriented Pangasius catfish production in Vietnam’s Mekong Delta is unparalleled in terms of rapidity and scale by any other agricultural sector, with production climbing from a low base to more than 1 million tons in a single decade. This paper examines the effects of this remarkable change on the rural class structure in locations where catfish farming has boomed, and analyses the role of local state-society relations in mediating outcomes resulting from the integration of local actors into the global value chain. We conclude that private economic activity is deeply embedded in informal relations with the state bureaucracy in Vietnam, with the result that the expansion of catfish aquaculture has generally acted to reproduce and entrench existing class relations rather leading to a radical reconfiguration of the rural class structure.  相似文献   
123.
Noah Quastel 《Geoforum》2011,42(4):451-461
While geographers have increasingly focused on how global commodity and production networks create new ‘geographies of responsibility’ there has been little empirical work considering how responsibility is worked into management systems and social activism in such networks. Drawing on literature from global production networks, geographies of responsibility and other literatures, this paper explores the dynamic and contested ways in which concepts of responsibility can play a role in network regulation. Both foreign direct investment and commodity networks (here referred to as ‘global production and investment networks’) are subject to complex negotiations and compromises involving corporate social responsibility and sustainability initiatives as well as shareholder activist, human rights, labor, and environmental activism. This is illustrated by reference to conflicts in Canada over Alcan, Inc.’s investments from 1993 to 2007 in the Utkal Alumina Project in Orissa, India. The project involved significant socio-environmental conflict. In Canada, Alcan’s investment was met by civil society campaigns that tested the company’s commitments to sustainability and corporate social responsibility. The case study suggests revising theories of geographies of responsibility. While foreign direct investment can create new relationships between distant others, these are fluid and contingent and not necessarily desirable. Rather than see networks as a source of responsibility we should work to ensure that the relationships that networks foster be structured to ensure our deeper values are respected.  相似文献   
124.
This paper begins by reviewing the structure and evolution of polar bear (Ursus maritimus) management in Canada and in the Territory of Nunavut since the inception of the Agreement on the Conservation of Polar Bears in the 1970s. This is followed by the paper's main focus, the examination of the socio-economic and cultural importance of polar bears for Inuit and the success of the Agreement in supporting contemporary Inuit subsistence relations in Nunavut.  相似文献   
125.
There is a great hiatus between Ordovician and Carboniferous strata in the Northeast China and Korean Peninsula. In order to understand geology and tectonic evolution, and to find out the similarities and differences in both regions, two sections in the Western Hill near Beijing in NE China and several sections in the Korean Peninsula were selected to examine their geologic boundaries between Lower and Upper Paleozoic strata to compare their characteristic features. At four sites in the two sections in the Western Hill near Beijing were examined their contact relations. The Hui Yu section is the same horizon where one site is top of a quarry hill and the other of down hill. Mid-Carboniferous Qingshuijian Formation rests on the Ordovician Majiagou Formation. Limestone beds are more commonly intercalated with shale and sandstone at site 2 of the Hui Yu section, while at site 1, conglomerate beds are dominant. Site 1 of the Se Shu Fen section shows eroded and concealed karst topography and conglomerate beds are intercalated within shale beds. Silurian and Devonian strata are absent in these areas. In the Korean Peninsula, most O-C contacts occur between Ordovician limestone formation and Carboniferous strata, although Silurian strata occur beneath the Carboniferous strata in the Jeongseon area and Pyeongnam Basin. Most contact relations are parallel unconformity and angular unconformity is rarely seen. The O-C relations in both regions are similar to each other, and these indicate that the Korean Peninsula was located near or belonged to the Sino-Korean paraplatform during Paleozoic time.  相似文献   
126.
澳大利亚Cloncurry地区大部分被元古宙地层所覆盖,其中赋存有大量世界级的成矿热液系统。大型热液系统大都与含磁铁矿或赤铁矿等铁氧化物的铁矿化岩石密切相关。铁氧化物和铜金矿化的矿物学、地球化学及年代学特征反映出成矿过程可能涉及到多种流体间的作用和水岩反应。对Cloncurry地区典型矿床和区域Na-Ca热液系统的研究表明,含铁氧化物的铁矿化岩石与铜金矿化之间的关系可分为4类:①贫磁铁矿或赤铁矿的"Kiruna-型"铁矿化岩石;②铜金矿化赋存于含铁氧化物的铁矿化岩石中;③与铁氧化物有关的铜金矿化;④少量或者不含铁氧化物的铜金矿化。该分类提供了一些与铁氧化物有关的铜金矿化成因联系、矿物学和矿化类型信息。  相似文献   
127.
尺度政治理论框架   总被引:10,自引:3,他引:10  
王丰龙  刘云刚 《地理科学进展》2017,36(12):1500-1509
目前国内外对尺度及尺度政治的讨论十分热烈。本文在整合已有研究的基础上,基于主体与结构视角提出了一个三阶段的尺度政治理论框架,指出政治过程和权力结构的尺度化是尺度政治的前提,尺度重构是尺度政治的核心机制,权力关系重构是尺度政治的目的和结果。具体而言,尺度化涉及物质空间、组织空间和表达空间的大小、层级、范围等结构关系;尺度重构包含由尺度上推、下推、重组,以及上述不同尺度形式构成的3×3矩阵;不同政治主体会采用特定尺度重构策略改变权力关系,并造成一系列尺度关系和合法性的悖论。基于以上认识,本文进一步讨论了中西方关于尺度和尺度政治的认知差异和未来值得深入研究的课题。  相似文献   
128.
Probabilistic aftershock hazard assessment (PAHA, Wiemer, Geoph Res Lett 27:3405–3408, 2000), provided for California within the frame of the STEP project, is based on a methodology, two features of which are addressed in detail: (1) the parameters of Omori’s law and (2) application of attenuation relations in evaluating peak ground velocity exceedence probability. Concerning the first point, we perform a simple parametric study. We assume the generalized Omori’s law by Shcherbakov et al. (Geoph Res Lett 31:L11613, 2004), in which characteristic time c scales with aftershock magnitude. The study shows that, among all the parameters, the hazard is most sensitive to the choice of m* (controlling the overall aftershock productivity) and least sensitive to the scaling of c. We also conclude that the hazard is mainly due to very early (less than 1 day) aftershocks. As regards the second point, we employ various attenuation relations from different tectonic areas to study their effect on the hazard analysis. We conclude that the resulting variations are relatively large, comparable to those obtained for varying m*.  相似文献   
129.
Source parameters estimated in the frequency domain for 100 selected seismic events from the Rudna copper mine, with moment magnitude ranging from 1.4 to 3.6, were collected to study their scaling relations and to compare them with the parameters estimated in the time domain. The apparent stress and static stress drop, corrected for the limited bandwidth recording, increase slightly in a similar manner with increasing seismic moment. The ratio of apparent stress to static stress drop, a measure of radiation efficiency, is practically constant and its mean value is close to 0.1. For 37 seismic events, with moment magnitude between 1.9 and 3.4, source parameters were estimated in the time domain from relative source time functions, that displayed unilateral rupture propagation, and their rupture velocity could be estimated. It ranges from 0.23 to 0.80 of shear wave velocity and is almost independent of seismic moment. The fault length, estimated from the average source pulse width and rupture velocity, is clearly dependent on seismic moment and is smaller than the source radius estimated from the corner frequency on the average by about 25 percent. There is no correlation between the values of static stress drop estimated in the frequency and time domains, but the time domain stress drop is in general similar to that estimated in the frequency domain. The apparent stress increases with increasing rupture velocity, and the ratio of apparent stress to static stress drop seems also to depend on rupture velocity.  相似文献   
130.
多尺度地图空间相似关系基本问题研究   总被引:8,自引:0,他引:8  
基于多尺度地图数据库建设中地图自动综合的终止判断条件,引出多尺度地图空间相似关系问题。基于集合论给出空间相似关系的定义,论述空间相似关系的5个性质,即反身性、对称性、非传递性、多尺度自相似性与尺度依赖性;并从图形相似和属性相似的角度论述多尺度地图空间相似关系的分类体系。该成果是研究地图自动综合和地图空间相似查询等的基础。  相似文献   
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