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941.
Sarah Turner 《Singapore journal of tropical geography》2013,34(1):9-24
Within the politically‐defined Greater Mekong Subregion (GMS), the borderlands of southeast Yunnan, China and Lào Cai province, northern Vietnam, have been categorized as being part of the GMS North‐South Economic Corridor. I argue that the creation of this subregion and corridor have been an opportunity for the governments in these locales to extend their territorialization and create new state spaces. For centuries, relatively isolated and ignored by lowland rulers, ethnic minority residents in these borderlands maintained their own culturally appropriate livelihoods, trade networks and societies. Nowadays, an increasing state presence in the uplands presents both challenges and opportunities for local populations on either side of the border, be they ethnic minorities, or Kinh (lowland Vietnamese) and Han Chinese. Contemporary border narratives gathered from local traders managing important upland commodities shed light on the means by which these borderland spaces are shaping both attractive prospects as well as restrictive constraints. Local residents fashion new trading‐scapes by drawing on kin ties, historical linkages, local indigenous knowledges and transnational societies that reach deep inside each country. As inhabitants carefully avoid or manipulate the state's gaze, I conclude that those living in the Sino‐Vietnamese borderlands possess the agency to ‘do things differently’ from hegemonic development approaches supported by GMS sponsors, and can create, maintain, support and refashion culturally appropriate trade livelihoods. 相似文献
942.
Sarah A. Elwood 《Urban geography》2013,34(8):737-759
Through recent changes in urban governance practices, citizens and community organizations assume ever-greater responsibility for local-level planning and service delivery. Scholars have debated whether this shift disempowers community organizations by subsuming their plans and priorities into state planning imperatives or empowers them through inclusion of community priorities and local knowledge. In carrying out their new responsibilities, many community organizations are adopting tools such as GIS. Strikingly similar questions have been raised about empowerment, disempowennent, incorporation, and autonomy; but relatively little work has systematically documented the ways in which GIS use alters community-level decision-making efforts. In this paper, I show how GIS use fosters changes in the language, practices, and paradigms of community planning, particularly strengthening an instrumental rational approach to community planning and revitalization. Drawing on research with a Minneapolis, Minnesota, neighborhood organization, I argue that these impacts of GIS use on community planning practices complicate and intensify a dynamic tension between incorporation and autonomy that community organizations experience within collaborative governance approaches. [Key words: community-based planning, GIS, urban governance.] 相似文献
943.
944.
Geology and stratigraphy of King crater, lunar farside 总被引:1,自引:0,他引:1
Clementine and photographic data sets have been used to investigate the crustal stratigraphy and geology of King crater on the lunar farside (120°E, 5.5°N). Pre-existing topographic regimes or stress fields dominate many structures in the crater, which has excavated materials from depths of up to 14 km. The upper crust in the area is noritic anorthosite, grading to a more anorthositic signature with depth. A possible batholithic intrusion is also present in a 15-km-wide band, extending from the southern crater floor to at least 50 km north of King, and from near-surface levels down to at least the excavation depth of the crater. It is generally feldspathic, but is cut by mafic dykes now visible in the north wall. King also shows evidence for the presence of a cryptomare, exposed in regions of the peaks and in dark halo craters within the ejecta blanket. Localized olivine-bearing mineralogies are observed on the central peaks, suggesting isolated pockets of troctolitic mineralogies to have been present at 8- to 14-km depths. Copious volumes of crystalline melt produced from the impact event cover King’s floor to a maximum thickness of 30-60 m, and have pooled in a number of natural depressions outside of the main crater. The main pool in the pre-existing A1-Tusi crater has a minimum depth of 150 m. Domes on the crater floor are verified as nonvolcanic in origin, and did not act as a source for any of the lava-like materials in King. 相似文献
945.
Sarah L. WILKISON Timothy J. McCOY Jane E. McCAMANT Mark S. ROBINSON Daniel T. BRITT 《Meteoritics & planetary science》2003,38(10):1533-1546
Abstract— Densities and porosities of meteorites are physical properties that can be used to infer characteristics of asteroid interiors. We report density and porosity measurements of 42 pieces of 30 ordinary chondrites and provide a quantification of the errors of the gas pycnometer method used in this study. Based on our measurements, we find that no significant correlation exists between porosity and petrologic grade, chemical group, sample mass, bulk and grain density, or shock level. To investigate variations in porosity and density between pieces of a meteorite, we examined stones from two showers, Holbrook and Pultusk. Examination of nine samples of Holbrook suggests relative homogeneity in porosity and density between pieces of this shower. Measurements of three samples of Pultusk show homogeneity in bulk density, in contrast to Wilkison and Robinson (2000), a study that reported significant variations in bulk density between 11 samples of Pultusk. Finally, examination of two friable ordinary chondrites, Bjurböle and Allegan, reveal variability in friability and porosity among pieces of the same fall. We suggest that friable ordinary chondrites may have formed in a regolith or fault zone of an asteroid. 相似文献
946.
A. J. S. Hamilton † 《Monthly notices of the Royal Astronomical Society》2001,322(2):419-425
Formulae are presented for the linear growth factor D a and its logarithmic derivative d ln D /d ln a in expanding Friedmann–Robertson–Walker universes with arbitrary matter and vacuum densities. The formulae permit rapid and stable numerical evaluation. A fortran program is available at http://casa.colorado.edu/~ajsh/growl/. 相似文献
947.
948.
Sarah Elwood 《GeoJournal》2002,58(2-3):121-130
With the increasing involvement of local citizens and community organizations in carrying out urban planning and service delivery functions formerly handled by state institutions, questions have emerged about their implications for the urban political role and influence of community level actors. Some scholars identify these purportedly collaborative neighborhood revitalization initiatives as part of a neoliberal policy program of downsizing the state, while others argue that the new roles assumed by civic institutions offer new opportunities for citizen involvement in urban policy making and priority setting for revitalization. Drawing evidence from the case of a collaborative revitalization program in Minneapolis, Minnesota, this paper suggests that collaborative revitalization efforts may simultaneously foster both tendencies. By way of the new roles they are assuming in urban governance, grassroots organizations may become engaged in reproducing neoliberal priorities and policies at a highly localized level. At the same time, this involvement does not necessarily eliminate possibilities for community organizations to challenge and revise a neoliberal revitalization agenda. 相似文献
949.
950.
Sources and transport of carbon and nitrogen in the River Sava watershed, a major tributary of the River Danube 总被引:1,自引:0,他引:1
Nives Ogrinc Roland Markovics Tjaa Kandu
Lynn M. Walter Stephen K. Hamilton 《Applied Geochemistry》2008,23(12):3685-3698
Carbon and nitrogen dynamics were examined throughout the River Sava watershed, a major tributary of the River Danube, in 2005 and 2006. The River Sava exported 2.1 × 1011 mol C/yr as dissolved inorganic carbon (DIC), and emitted 2.5 × 1010 mol C/yr as CO2 to the atmosphere. Stable carbon isotope ratios indicate that up to 42% of DIC originated from carbonate weathering and 23% from degradation of organic matter. Loads of dissolved and particulate organic carbon increased with discharge and export rates were calculated to be 2.1 × 1010 mol C/yr and up to 4.1 × 109 mol C/yr, respectively. Isotopic compositions (δ13C and δ15N) and C/N ratios indicated that soil organic matter was the dominant source of particulate organic matter for 59% of the samples. Eighteen percent of the samples were dominated by plankton, 12% by periodic inputs of fresh terrestrial plant detritus with C/N > 15, and about 11% of the samples were dominated by the contribution of aquatic vascular plants. Nitrate inputs were controlled by land use in the River Sava watershed. δ15NNO3 values <6‰ were found in predominantly forested watersheds, while values >6‰ typically represented watersheds with a higher percentage of agricultural and/or urban land use. Elevated δ15NNO3 values (up to +25.5‰) at some sites were probably due to the combined effects of low-flow and inputs from sewage and/or animal waste. 相似文献