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1.
Mumbai’s Dharavi slum occupies a plot half the size of Central Park. It is home to one million people, with almost half of residents living in spaces under 10 m2, making it over six times as dense as daytime Manhattan. Using ethnographic fieldwork and online analysis, this article examines slum tourism and the perceptions and experiences of western visitors. Local tour operators emphasize the productivity of the slum, with its annual turnover of $665 million generated from its hutment industries. Its poor sanitation, lack of clean water, squalid conditions and overcrowding are ignored and replaced by a vision of resourcefulness, hard work and diligence. This presentation of the slum as a hive of industry is so successful that visitors overlook, or even deny, its obvious poverty. Dharavi is instead perceived as a manufacturing hub and retail experience; and in some cases even romanticized as a model of contentment and neighbourliness, with western visitors transformed by ‘life-changing’, ‘eye-opening’ and ‘mind-blowing’ experiences. This article concludes that the potential of slum tours as a form of international development is limited, as they enable wealthy middle-class westerners to feel ‘inspired’, ‘uplifted’ and ‘enriched’, but with little understanding of the need for change.  相似文献   

2.
Coworking spaces (CWS) and the associated practice of coworking, have emerged in numerous forms and various urban contexts to critically challenge traditional concepts of the workplace and location of creative work, while simultaneously confronting the way in which creative workers interact with and relate to each other as well as with space and to place. Heralded as a solution to increasingly atomised work patterns, CWS are imagined and presented as spaces of serendipitous encounter, spontaneous exchange and collaboration. Nonetheless, little is known about how coworking positively supports workers and how coworking relates to wider urban transformation processes has been largely un-researched. This paper contributes to a critical discussion through empirical analysis of a project aimed at establishing new creative CWS in city-centre locations across SE England. The study adopts a novel approach using Q-methodology. Motivations for coworking and benefits (or dis-benefits) of co-location are assessed, as is the extent to which coworking facilitates interactional effects and wider neighbourhood interactions. In particular, the role of the CWS manager as “mediator” is explored. Coworker benefits relate primarily to peer-interaction and support rather than formal collaboration. While CWS managers play a key connecting role, also ensuring coworker complementarity and compatibility, the coworker profile (motivations, needs, experiences) ultimately influences outcomes. The study cautions against the use of CWS as “quick fix” urban renewal tools, with little indication that the benefits of coworking reach beyond immediate members or that linkages are easily established between coworkers and local (resident or business) communities.  相似文献   

3.
Arid and Alpine ecosystems are known for extreme environmental changes during the Late Quaternary. We hypothesize that the world's largest Alpine arid ecosystem however, the Alpine Steppes of the Tibetan highlands, remained ecologically stable during the LGM and the mid-Holocene. This hypothesis is tested by distributional range of plant species, plant life forms and rate of endemism. The set of character species has a precipitation gradient between 50 and 350 mm/a, testifying for resilience to precipitation changes. 83% of the species have a wider vertical range than 1000 m used as a proxy for resilience to temperature changes. 30% of the species are endemic with 10 endemic genera, including plate-shaped cushions as a unique plant life form. These findings are in line with palaeo-ecological proxies (δ18O, pollen) allowing the assumption that Alpine Steppes persisted during the LGM with 3 to 4 K lower summer temperatures.During the mid-Holocene, forests could have replaced Alpine Steppes in the upper catchments of the Huang He, Yangtze, Mekong, Salween and Yarlung Zhangbo, but not in the interior basins of the north-western highlands, because the basins were then flooded, suppressing forests and supporting the environmental stability of this arid Alpine grassland biome.  相似文献   

4.
Since the coexistence of the Cretaceous and Palaeocene was ascertained in the Hengyang Basin of Hunan in the middle of the 1960's, the Cretaceous and Tertiary boundary has been discussed in several papers, but it still remains controversal. The points at issue are the connotation, stratigraphical position and lateral correlation of the Dongtang (or Chejiang) Formation.  相似文献   

5.
A method to predict the enthalpy of formation is based on the parameter HO2-cation (comp) (Vieillard 1982; Vieillard and Tardy 1988a). The calculation of this parameter requires the knowledge of cristallographical and optical properties of minerals (refractive index, molar volume, average distances and shortest bond lengths of cation-oxygens in all sites, existence of hydrogen bonding, presence of a order-disorder in a site of the involved compound). This method has been tested on a great number of minerals and artificial compounds belonging to the system: Li2O-Na2O-K2O-BeO-MgO-CaO-MnO-FeO-Fe2O3-Al2O3-SiO2-H2O (180 minerals) (Vieillard 1994a, b). When several structure refinements of the same mineral are present, several factors such as precision of crystal structure determination, chemical composition, existence of any disorder in a site, presence of hydrogen bonding and estimated standard deviation on bond lengths seem to play an important role in the predication of enthalpy of formation from oxides. Muscovite and natrolite, for which numerous structure refinements are available, are used and discussed in this study.  相似文献   

6.
With rising public awareness of climate change, celebrities have become an increasingly important community of non nation-state ‘actors’ influencing discourse and action, thereby comprising an emergent climate science-policy-celebrity complex. Some feel that these amplified and prominent voices contribute to greater public understanding of climate change science, as well as potentially catalyze climate policy cooperation. However, critics posit that increased involvement from the entertainment industry has not served to influence substantive long-term advancements in these arenas; rather, it has instead reduced the politics of climate change to the domain of fashion and fad, devoid of political and public saliency. Through tracking media coverage in Australia, Canada, the United States, and United Kingdom, we map out the terrain of a ‘Politicized Celebrity System’ in attempts to cut through dualistic characterizations of celebrity involvement in politics. We develop a classification system of the various types of climate change celebrity activities, and situate movements in contemporary consumer- and spectacle-driven carbon-based society. Through these analyses, we place dynamic and contested interactions in a spatially and temporally-sensitive ‘Cultural Circuits of Climate Change Celebrities’ model. In so doing, first we explore how these newly ‘authorized’ speakers and ‘experts’ might open up spaces in the public sphere and the science/policy nexus through ‘celebritization’ effects. Second, we examine how the celebrity as the ‘heroic individual’ seeking ‘conspicuous redemption’ may focus climate change actions through individualist frames. Overall, this paper explores potential promises, pitfalls and contradictions of this increasingly entrenched set of ‘agents’ in the cultural politics of climate change. Thus, as a form of climate change action, we consider whether it is more effective to ‘plant’ celebrities instead of trees.  相似文献   

7.
Isotopic ages of synsedimentary clay minerals were directly determined with the ultrasonicscattering-settlement separation-K-Ar dilution technique. The apparent age of black mudstoneis 123 Ma for the Quantou Formation, 111.9-89.0 Ma for the Qingshankou Formation and77.6-76.8 Ma for the upper part of the Nenjiang Formation. The Rb-Sr isochrone age of themuddy limestone-mudstone sequence of the lower part of the Nenjiang Formation is 81 Ma andthat of the muddy evaporite of the middle part of the Quantou Formation is 122.2 Ma. On thebasis of the above isotopic ages, the authors propose a modified scheme of stratigraphic classifi-cation of the Cretaceous of the Songliao basin.  相似文献   

8.
Placer gold particles derived from epithermal deposits display distinct morphological and compositional features compared with particles from mesothermal systems. Here, it is hypothesized that the chemical composition of primary gold derived from different deposit types is a principle factor affecting the composition of resident biofilm communities as well as the transformation of placer particles. Gold particles were collected from placers originating from the epithermal system at the Eisenberg, Germany's largest primary gold deposit. For comparison, placer gold from mesothermal sources was studied. Morphological differences due to mechanical transport and physical reshaping were not observed. Biogeochemical gold/silver dissolution and gold re-precipitation were evident on epithermal particles and they accentuate the silver-fabrics and gold-rich clusters. In contrast, on mesothermally derived gold particles these processes led to the development of gold-rich rims via the formation of nano-porous secondary gold. Microprobe- and laser ablation mass spectrometric analyses of polished whole particle mounts confirmed differences in gold/silver content/distribution and trace metal content between particles from epi- and mesothermal sources, respectively. On particles from all sites nano- and micro-particulate gold is associated with polymorphic layers. These are composed of microbial cells, extracellular polymeric substances (EPS) and clay-sized minerals. Multivariate statistical analyses shows a significant difference between biofilm communities from epi- vs. mesothermally derived particles, which is linked to the chemical composition of the primary gold. While a number of key-species capable of gold transformation, e.g., Cupriavidus sp., Geobacter sp. and Rhodoferax sp., were detected on particles from both sources, higher numbers of organisms with the potential for gold solubilization, precipitation and detoxification were associated with particles from the epithermal sources. A range of species involved in gold transformation, i.e., Arthrobacter spp., Delftia sp., Shewanella sp., and Stenotrophomonas spp., were detected only on epithermally derived placer gold. This indicates the communities are sensitive to differences in gold/silver and possibly trace metal-cycling, resulting from differences in their content, distribution and mobilization behaviour in epi- vs. mesothermally derived particles. Ultimately, this study shows that the chemical composition of the primary deposit strongly influences the biogeochemical transformation of placer gold and the composition of associated biofilms, whereas physical transformations appear to be largely unaffected.  相似文献   

9.
The paper deals with the metallogenic conditions and regularities of the region ol the lower-middle reachesof the Changjiang River in China. The complicated structural network with the Changjiang (Yangtse) deepfracture as its trunk is the leading rock-and ore-controlling structure of the metallogenic belt. Thehigh-potassium granodiorites of the first magmatic sequence of the Mesozoic Yangtse syntexis type and thesodium-rich diorites of the second sequence are genetically related to the copper ore series and the iron ore se-ries respectively. and occur respectively in the block-faulted and-folded uplift area and the down-faulted vol-canic basin as well as the transitional zone between the two. The ore-hosting horizons show specific associa-tions of rocks and often contain ore beds basically of stratabound nature.  相似文献   

10.
A simple mechanical model explaining the long-period (about 100-year) variations in the Earth’s rotational velocity is proposed. This model takes into account the gravitational interaction of the mantle with the solid core of the Earth and the fact that the core rotation leads that of the mantle. Well-known Earth parameters provide estimates of the gravitational torque that support the proposed model. The mathematical problem involved reduces to the classical problem of a nonlinear oscillator exposed to a constant torque. The well-known parameters of the core-mantle system result in a stable equilibrium and a stable limiting cycle on the phase cylinder of this oscillator. This equilibrium corresponds to a single angular velocity for the mantle and solid core, with no long-period oscillations in the length of the day. The limiting cycle corresponds to the core rotation leading the mantle rotation. In this case, the ellipsoidality of the gravitationally interacting bodies provides a periodic interchange of kinetic angular momentum between the mantle and solid core that results in long-period variations in the length of the day. The proposed model does not support the formerly widespread opinion that the core rotates more slowly than the mantle.  相似文献   

11.
The global extraction of minerals is commonly located in areas populated by indigenous people; and while conflicts between multinational corporations and local activists and indigenous people are widespread today, the understanding of their dynamics are lacking. The Swedish government’s encouragement to an expanding mining industry has caused resistance due to environmental and social implications, particularly its effect on Sámi reindeer husbandry. The resistance to a mine in Gállok is based on the belief that the right to decide about land use historically falls on the Sámi people, and the right to affect land use is detrimental for the survival of Sámi culture and reindeer husbandry. Although the conflict may be perceived as concerning access to natural resources, we argue that the perceived environmental conflict can be viewed as part of a larger struggle over social status and recognition. Data have been collected using qualitative methods such as observations, interviews and documents. The subsequent analysis relies on a meta-theoretical framework of justice as recognition using a typology of relations of power. Our findings suggest that relations of power constitute different categories of social actors. Stakeholders like the Sámi population are subordinated to more dominant stakeholders such as the government, the company and media, who have ‘more’ power or ‘different’ kinds of power ‘over’ others. Through these asymmetric power relations, historical state-Sámi relations are continuously reproduced within prevailing institutions, and also in this mining conflict. Interviewees from business and the municipality testified to the discourses driven by a neoliberal and profit-focused worldview. Challenging the neoliberal discourse, other stakeholders, namely civil society and Sámi, expressed an alternative discourse based on a local, traditional, cultural, environmental and anti-neoliberal worldview.  相似文献   

12.
The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwater in the region of the middle and lower reaches of the YangtzeRiver and their relations to the composition of the water-bearing media, properties of the overly-ing rocks and soils, redox environment, and groundwater flow condition, mineralization and pHof groundwater.  相似文献   

13.
Early Paleozoic paleomagnetic data from NW Argentina and Northern Chile have shown large systematic rotations within two domains: one composed of the Western Puna that yields very large (up to 80°) counter-clockwise rotations, and the other formed by the Famatina Ranges and the Eastern Puna that shows (~40°) clockwise rotations around vertical axes. In several locations, lack of significant rotations in younger rocks constrains this kinematic pattern to have occurred during the Paleozoic. Previous tectonic models have explained these rotations as indicative of rigid-body rotations of large para-autochthonous crustal blocks or terranes. A different but simple tectonic model that accounts for this pattern is presented in which rotations are associated to crustal shortening and tectonic escape due to the collision of the allochthonous terrane of Precordillera in the Late Ordovician. This collision should have generated dextral shear zones in the back arc region of the convergent SW Gondwana margin, where systematic domino-like clockwise rotations of small crustal blocks accommodate crustal shortening. The Western Puna block, bordering the Precordillera terrane to the north, might have rotated counterclockwise as an independent microplate due to tectonic escape processes, in a fashion similar to the present-day relationship between the Anatolia block and the Arabian microplate.  相似文献   

14.
Geotectonics - The geological and sedimentological interpretation of several time and deep seismic profiles within junction zone of the Volga‒Ural area of the East European Platform,...  相似文献   

15.
LUHR  JAMES F. 《Journal of Petrology》1990,31(5):1071-1114
The equilibrium phase relations of two volcanic rocks from thesubduction-related Mexican Volcanic Belt have been determinedwith an argon-pressurized internally heated vessel. One rockis the trachyandesite erupted from El Chich?n Volcano in 1982;the other is a primitive basalt erupted from Jorullo Volcanoin 1759. A simplified synthetic equivalent to the trachyandesitewas also investigated in lesser detail. All charges were saturatedwith hydrous vapor and a sulfur-bearing mineral. Temperatureranged from 800 to 1000?C, pressure from 1 to 4 kb, and fo2was controlled by four different solid oxygen buffers in a doublegold capsule configuration: fayalite-magnetite-quartz (FMQ),Ni-NiO (NNO), manganosite-hausmanite (MNH), and magnetite-hematite(MTH). Pyrrhotite was the only sulfur-bearing mineral observed in chargesbuffered under FMQ and NNO, whereas anhydrite crystallized underthe more oxidizing MNH or MTH; both of these observations areconsistent with those of earlier workers. With increasing temperatureand pressure, SiO2 and K2O decreased in the experimental melts,whereas Al2O3 and CaO increased. Sulfur solubility in silicatemelts was low (<0?1 wt% equivalent SOt3) for pyrrhotite-saturatedcharges, but significantly greater (to 1?3 wt.% SOt3) when anhydritewas present. Sulfur solubility in anhydrite-saturated meltsshowed strong positive dependence on both temperature and Pvapor. Sulfur amounted to some 2?5 wt.% (SOt3) of the total ejectaduring the 1982 El Chich?n eruptions, and the original magmaticsulfur content was in the range 1?25–2–5 wt% SOt3.Extrapolations of experimental temperature and pressure dependencesfor sulfur solubility indicate that such concentrations couldbe contained in a hydrous, oxidized, basaltic parent melt generatedunder Benioff zone conditions. During ascent through the uppermantle and crust, the sulfur solubility limit of the melt wouldcontinuously decrease; in response, most of the sulfur wouldbe transferred from the melt to anhydrite crystals and a separategas phase. Trachyandesite pumices erupted from El Chich?n in1982 contained both pyrrhotite and anhydrite at a temperatureof 800?C. The composition of the natural pyrrhotite yieldedan fo2 estimate 1 log unit above the NNO buffer. Based on compositionalvariations in the experimental melts with temperature and pressure,the composition of the matrix glass in the 1982 pumices indicatesequilibration of the magmatic liquid at about Ptotal=Pvapor=2kb just before eruption. At that time, sulfur in El Chich?ntrachyandesite was about equally partitioned between anhydritemicrophenocrysts and some 20 vol.% gas phase in which H2S wasprobably the dominant sulfur-bearing species. The melt thencontained only 0?05 wt.% SOt3, consistent with experimentalsolubility limits at 800?C and Pvapor=2 kb.  相似文献   

16.
Through an analysis of the earliest fossils in the Precambrian-Cambrian boundary beds in various parts ofthe world, especially in the Yangtze and Siberia platforms, the author has found that the evolution of the ea-rliest skeletal animals may be divided from older to younger into three stages. The first stage (theAnabarites-Protohertzina fauna) is represented by the Anabarites-Protohertzina zone of the Meishucunian Stagein the Yangtze platform and the A. trisulcatus and P. cristata zones of the Manykayn Stage in Siberia. The sec-ond stage (the earliest orthothecimorphid and mollusc fauna) is represented by the Paragloborilus-Siphogonuchites zone of the Meishucunian Stage and the Aldanocyathus sunnaginicus zone of the TommotianStage. The third stage (the earliest hyolithimorphid and lapworthellid fauna) is represented by the Sinosachiteszone of the Meishucunian Stage and the D.regularis and D.lenaicus zones of the Tommotian Stage. The threeevolutionary stages can be used as a criterion for worldwide correlation.  相似文献   

17.
Recent free-air gravity data covering the Makassar Straits is integrated with Bouguer gravity data from onshore East Kalimantan to provide new insights into the basement structure of the region. Onshore Kalimantan, gravity highs on the northern margin of the Kutai Basin trend NNE–SSW and N–S and correspond with the axes of inverted Eocene half-grabens. NW–SE trending lows correspond to deep seated basement weaknesses reactivated as normal faults during the Tertiary. An intra-basin gravity high trending NNE–SSW, the Kutai Lakes Gravity High, is modelled as folded high density Paleogene sediments flanked by syn-inversion synclines infilled with low density sediments. Offshore Kalimantan, the Makassar Straits include two basins offset by an en-echelon fault zone, suggestive of an extensional origin. The regional signature of the free-air anomaly data mirrors the bathymetry, but this effect can be reduced by the use of filters in order to examine the basin architecture. The free-air gravity minimum in the Makassar Strait is only −20 mGal, much smaller than that appropriate for a foreland basin, and more indicative of an extensional basin. The steepness of the gradients on the flanks of the basins indicates fault control of their margins. A regional 2D profile across the North Makassar Basin suggests the presence of attenuated crust (<14 km) in the basin axis at the present day, whereas flexural backstripping implies the presence of oceanic crust of middle Eocene age. The presence of oceanic crust in the North Makassar Straits Basin has implications for regional plate tectonic models.  相似文献   

18.
This study focused on the geochemical distribution patterns and ecological effects of Cd and other heavy metals such as As, Hg, Cr, Cu, Ni, Pb, and Zn in rock, soil, water, sediment and crops in the area of the Three-Gorges Reservoir within Chongqing, and aimed at the protection of ecological environment and rational application of the local lands. This study found that the metals of Cd, Hg and Pb presented pollution in the surface environment along the Yangtze River, that is Cd〉Hg〉Pb (Cu)〉Zn〉As〉Ni〉Cr. The pollution of Cd in sediment was mainly attributable to the regional black shales, and partly to the urban sewage and garbage. The geochemical modes of metals in the sediment varied. Cr, Hg, Ni, and Pb mainly existed as residues, and Cd as carbonate. Cd exited as a high proportion in the modes of ion-exchange, carbonate, and iron-manganese oxidation, up to 63 percent. The contents of heavy metals in soiland sediment were correlated to the host clay minerals, such as illite, montmorillonite, kaolinite and chlorite. It is shown that Cd was transported with clay minerals in the Yangtze River over long distance and formed the regional anomaly. In the abnormal area of Jianping in Wushan County, higher Cd contents are reported in the local crops and local villagers' hairs than from the background areas.  相似文献   

19.
Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8-1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47-0.71 and Ba/Ba*=0.16-0.64), with fDM and εNd(1.0 Ga) ranging from 1.87 to 2.26 Ga and from -8.54 to -4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane wer  相似文献   

20.
Over the past two decades development has been shifting its focus toward smaller scales and particular problems. As a result, the household has become an increasingly important institution for development, and has come under increased scrunity as development practitioners and scholars seek to better understand this institution’s functions and foundations, trying to ‘get the household right’. These efforts, rather than clarifying the character and the function of the household, have contributed to its indeterminacy by reifying the very institution they seek to analyse. Arguing that these efforts fundamentally miss the point of examining the household, this paper introduces a different framework of analysis that addresses the household not as a fixed object of research, but as a local construction that embodies flows of power and knowledge both within and transcending the local. Using the example of varying constructions of the household in two villages in Ghana’s Central Region, this article illustrates how such an approach allows us to address the various functions of the household as particular embodiments of these flows, an approach that better explains the endurance or ephemerality of these functions. Such an approach provides a stronger foundation for the consideration of how particular constructions of this institution may have troubling implications for issues like gender equity and sustainability.  相似文献   

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