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31.
There is a growing understanding that energy services play a crucial role in underpinning efforts to achieve the UN Millennium Development Goals (MDG) and in improving the lives of poor people. Brazil remains challenged in regard to a number of social issues, notably poverty reduction in isolated areas, where access to electricity is as poor as their population. In the Amazonian region, most people have no access to electricity, or else have only a precarious supply. Due to several economic and technical reasons, many cities have old, inefficient diesel generators. In such a scenario, CDM (Clean Development Mechanism) can be an instrument both to mitigate climate change and to promote sustainable development in these remote areas, thereby contributing to the achievement of the MDGs in Brazil. However, CDM implementation in Brazil is still restricted to a few types of projects (such as sugar cane bagasse cogeneration and landfill gas use), mostly proposed by big companies and hardly ever directed to the Amazon region. The main objectives of this article are to assess the potential of CDM as a possible tool to promote electricity access to the poor rural population in the Amazonian region, and to discuss the main reasons why it has not become a reality so far.  相似文献   
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Seafloor hydrothermal alteration at an Archaean mid-ocean ridge   总被引:2,自引:0,他引:2  
A hydrothermally metamorphosed/altered greenstone complex capped by bedded cherts exposed in the North Pole, Pilbara Carton, Western Australia, is interpreted as an accretionary complex. It is distinctive in being characterised by both duplex structure and an oceanic crust stratigraphy. This complex is shown to represent an Archaean upper oceanic crust with a mid‐ocean ridge hydrothermal metamorphism that increases in grade stratigraphically downward. Three mineral zones have been defined; Zone A of the zeolite facies, the prehnite‐pumpellyite facies or the lower‐greenschist facies at high‐XCO2 condition, Zone B of the greenschist facies, and Zone C of the greenschist/amphibolite transition facies. In Zone A metabasites, Ca‐Al silicates including Ca‐zeolites, prehnite and pumpellyite are absent and epidote/clinozoisite is extremely rare. Instead, abundant carbonates are present with chlorite suggesting high‐XCO2 composition in the fluid. On the other hand, in Zones B and C metabasites, where Ca‐amphibole + epidote/clinozoisite + chlorite + Ca‐Na plagioclase are the dominant assemblages, carbonate is not identified. The metamorphic conditions boundary of Zones B/C were estimated to be about 350 °C at a pressure of <0.5 kbar. Fluid compositions coexisting with Archaean greenstones at the transition between Zones B and C were estimated by thermodynamic calculation in the CaFMASCH system (T = 350–370 °C, P = 150–1000 bar) at XCO2 of 0.012–0.140, such values are higher than present‐day vent fluids collected near mid‐ocean ridges with low‐XCO2 values, up to 0.005. The Archaean seawater depth at the mid‐ocean ridge was estimated to be 1600 m at XCO2 = 0.06 using a depth‐to‐boiling point curve for a fluid. The carbonation due to high‐XCO2 hydrothermal fluids occurred near the ridge‐axis before or was coincident with ridge metamorphism.  相似文献   
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Developing techniques are required to generate agricultural land cover maps to monitor agricultural fields. Landsat 8 Operational Land Imager (OLI) offers reflectance data over the visible to shortwave-infrared range. OLI offers several advantages, such as adequate spatial and spectral resolution, and 16 day repeat coverage, furthermore, spectral indices derived from Landsat 8 OLI possess great potential for evaluating the status of vegetation. Additionally, classification algorithms are essential for generating accurate maps. Recently, multi-Grained Cascade Forest, which is also called deep forest, was proposed, and it was shown to give highly competitive performance for classification. However, the ability of this algorithm to generate crop maps with satellite data had not yet been evaluated. In this study, the reflectance at 7 bands and 57 spectral indices calculated from Landsat 8 OLI data were evaluated for its potential for crop type identification.  相似文献   
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兰州市孔家崖断裂活动特征   总被引:2,自引:0,他引:2       下载免费PDF全文
主要根据调查资料及电测深、钻探资料论述了孔家崖断裂的展布以及第四纪以来不同地质时期活动特征.早更新世以来该断裂的平均倾滑速率为0.17~0.21mm/a,全新世以来平均倾滑速率为0.2mm/a.根据该断裂的展布及活动特征对某场区的工程建设提出了一些建议.  相似文献   
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Journal of Atmospheric Chemistry - Rapid transport by deep convection is an important mechanism for delivering surface emissions of reactive halocarbons and other trace species to the tropical...  相似文献   
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It is important to evaluate bedload discharge and temporal changes of the bed surface, and bed deformation can be estimated during floods if the bedload discharge is properly evaluated in an arbitrary cross‐section. With the exception of grain size and its distribution within the bedload, bedload discharge has been measured using both direct and indirect methods. Bedload slot is a direct method but cannot be used to measure bedload during a flood because of volume limitations. Indirect methods require correlation between the signals and sediment volume measured using another method. In the present study, a small, automatically recording bedload sensor with an iron plate and a pair of load cells is developed in order to evaluate not only large particles but also sand particles as bedload. Bedload mass is calculated by integrating with respect to both the velocity of sediment particles and the averaged particle weight as measured by a pair of load cells, and, as an example, the velocity is estimated by the cross‐correlation function of weights measured by load cells. The applicability of the proposed sensor is discussed based on the results of flume tests in the laboratory (2014) and the observation flume of the Hodaka Sedimentation Observatory of Kyoto University in Japan (2015). The system was installed in the observation flume in November of 2012, and flume data were obtained using natural sediment particles. In particular, it was difficult to estimate the velocity of averaged bedload particles, and it was better to apply a cross‐correlation function in the laboratory tests. However, it appears that the previous estimation can estimate these velocities in the observation flume using a connecting tube and submerged load‐cell systems. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   
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