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91.
根据对元岭金矿三条蚀变破碎带一般地质特征、微量元素特征的对比研究,并借鉴邻近矿区蚀变破碎带的矿化特征,本文阐明了元岭蚀变破碎带矿化的有利构造部位,总结了蚀变破碎带特征与矿化强度之间的关系,指出蚀变破碎带的矿化蚀变元素为中低温组合,矿化蚀变愈强则参与元素的种类愈多、数量愈大。围岩性质对矿化蚀变有一定影响,围岩中的易迁移亲铜元素和亲硫铁族无素对矿化有利。据此,为进一步成矿预测、评价蚀变破碎带的含矿性提供依据。  相似文献   
92.
River terraces represent important records of landscape response to e.g. base-level change and tectonic movement. Both these driving forces are important in the southern Iberian Peninsula. In this study, Optically Stimulated Luminescence (OSL) dating was used to date two principal river terraces in the Tabernas Basin, SE Spain. A total of 23 samples was collected from the fluvial terraces for dating using quartz OSL. Sixteen of the samples could not be dated because of low saturation levels (e.g. typical 2xD0 < 50 Gy). The remaining seven samples (5 fossil and 2 modern analogues) were investigated using both multi-grain and single-grain analysis. Single grain results show that: (i) measurements from multi-grain aliquots overestimate ages by up to ∼ 4 ka for modern analogues and young samples (<5 ka), presumably because (ii) the presence of many saturated grains has biased the multi-grain results to older ages. Despite the unfavourable luminescence characteristics we are able to present the first numerical ages for two terrace aggradation stages in the Tabernas Basin, one at ∼16 ka and the other within the last 2 ka.  相似文献   
93.
Late glacial changes in the vegetation were studied in and around a former lake on the southeastern side of a coversand ridge near Milheeze (southern Netherlands). Analyses of microfossils and macroremains and AMS 14C dating were performed on four sediment cores along a transect from sand ridge to the lake centre. Small-scale vegetation patterns and lake-level fluctuations were reconstructed in detail based on the information provided by the transect. For the first time in The Netherlands, cores along a transect within one lake were used to reconstruct the amplitude of late glacial lake-level fluctuations. Near Milheeze, a small and shallow lake was formed during the Bølling. The large increase in the water level during the Bølling and early Allerød, and the transition to more eutrophic conditions at the start of the Allerød, were probably related to the disappearance of permafrost. During the Allerød, open birch and pine woodlands developed in the area. In the lake, organic deposits accumulated, and the lake size and depth fluctuated. At the start of the Younger Dryas, higher lake water levels were recorded and woodlands became more open as a result of both a drop in the temperature and an increase in the effective precipitation. During the late Younger Dryas the lake water level dropped as the climate became drier and temperatures slightly increased. Accumulation of organic deposits in the lake ceased at the end of the Younger Dryas, which was caused by a drop in the water level in combination with the hydroseral succession process within the lake itself. The climatic signal reflected in the late glacial flora and lake-level fluctuations agree well with other published data from The Netherlands.  相似文献   
94.
Mining operations are vital to sustaining our modern way of life and are often located in areas that have limited water supplies or are at an increased risk of the effects of climate change. However, few studies have considered the interactions between the mining industry and water resources on a global scale. These interactions are often complex and site specific, and so an understanding of the local water contexts of individual mining projects is required before associated risks can be adequately assessed. Here, we address this important issue by providing the first quantitative assessment of the contextual water risks facing the global base metal mining industry, focusing on the location of known copper, lead, zinc and nickel resources.The relative exposure of copper, lead-zinc and nickel resources to water risks were assessed by considering a variety of spatial water indices, with each providing a different perspective of contextual water risks. Provincial data was considered for water criticality (CRIT), supply risk (SR), vulnerability to supply restrictions (VSR) and the environmental implications (EI) of water use. Additionally, watershed or sub-basin scale data for blue water scarcity (BWS), the water stress index (WSI), the available water remaining (AWaRe), basin internal evaporation recycling (BIER) ratios and the water depletion index (WDI) were also considered, as these have particular relevance for life cycle assessment and water footprint studies. All of the indices indicate that global copper resources are more exposed to water risks than lead-zinc or nickel resources, in part due to the large copper endowment of countries such as Chile and Peru that experience high water criticality, stress and scarcity. Copper resources are located in regions where water consumption is more likely to contribute to long-term decreases in water availability and also where evaporation is less likely to re-precipitate in the same drainage basin to cause surface-runoff or groundwater recharge.The global resource datasets were also assessed against regional Köppen-Geiger climate classifications for the observed period 1951–2000 and changes to 2100 using the Intergovernmental Panel on Climate Change’s A1FI, A2, B1 and B2 emission scenarios. The results indicate that regions containing copper resources are also more exposed to likely changes in climate than those containing lead-zinc or nickel resources. Overall, regions containing 27–32% (473–574 Mt Cu) of copper, 17–29% (139–241 Mt Pb + Zn) of lead-zinc and 6–13% (19–39 Mt Ni) of nickel resources may have a major climate re-classification as a result of anthropogenic climate change. A further 15–23% (262–412 Mt) of copper, 23–32% (195–270 Mt) of lead-zinc and 29–32% (84–94 Mt) of nickel are exposed to regional precipitation or temperature sub-classification changes. These climate changes are likely to alter the water balance, water quality and infrastructure risks at mining and mineral processing operations. Effective management of long-term changes to mine site water and climate risks requires the further adoption of anticipatory risk management strategies.  相似文献   
95.
A rights-based approach to ‘adaptive social protection’ holds promise as a policy measure to address structural dimensions of vulnerability to climate change such as inequality and marginalisation, yet it has been failing to gain traction against production and growth-oriented interventions. Through the lens of Ethiopia’s flagship Productive Safety Net Programme (PSNP), we trace the role of climate discourses in impeding progress towards socially transformative outcomes, despite the importance of social protection for building resilience. We argue that intertwining narratives of moral leadership and green growth associated with Ethiopia’s national climate strategy shape how the PSNP is rendered ‘climate-smart’. These narratives, however, are embedded within politics that have historically underpinned the country’s drive for modernisation and growth-oriented policies, particularly in dealing with food insecurity. Like pre-existing narratives on development and the environment, they rationalise the presence of a strong central State and its control over natural resources and rural livelihoods. The PSNP is thus conditioned to favour technocratic, productivist approaches to adapting to climate change that may help reproduce, rather than challenge the entrenched politics at the root of vulnerability. Ultimately, this case study demonstrates how climate discourses risk diluting core rights-based dimensions of social protection, contradicting efforts to address the structural dimensions of vulnerability to climate change.  相似文献   
96.
介绍新型红外气体观测仪的结构、主要技术指标、优缺点以及解决其不足之处的方法;通过分析红外气体观测仪在台站试验中取得的观测数据,探索出一种将红外气体传感技术应用于断层气观测的新方法。  相似文献   
97.
In this intervention article I contribute to discussions of moral economy by arguing that scholars should reconsider the nature of value. Neoliberalism considers only exchange value. As a consequence neoliberal policies try to manage problems such as climate change with economic systems and instruments that are mis-calibrated to the material realities they are meant to represent. Value has spatial and temporal characteristics. Recognizing the spatial and temporal dynamics of value leads to new means of resource valuation, such as extending the time-frame of instruments and changing the nature of privatization. In conclusion, I argue for the need for new theories of use value.  相似文献   
98.
What have been the moral values and practices allowing equitable economic opportunities and a sense of fairness in North American small-scale fisheries? How have these “moral economies” been affected by neoliberal policies with their emphasis on efficiency, rational self-interest, and wealth accumulation? Focusing especially on the salmon and halibut fisheries in British Columbia, Canada, this discussion summarizes key findings on the manner in which small-scale fisheries and their moral practices tend to be marginalized and undervalued under neoliberal regimes. The paper considers the value of these moral economies for promoting social, economic, and ecological welfare as grounds for the expansion of small-scale fisheries.  相似文献   
99.
采用最近邻指数、Ripley’s L函数、核密度估计等方法分析长江经济带开发区的空间分布与产业集聚特征,结果表明:①长江经济带开发区总体上呈东密西疏、东强西弱、东中西段分异的显著集聚分布特征;②基于主导产业划分的各类开发区在空间上均为集聚分布,集聚强度和规模随距离的增加基本都呈"先增加后减小"的规律,集聚形态各异,主要有"单核心""双核心""多核心"3种;③长江经济带东段地区主要以装备制造、通信电子、汽车制造、新材料、生物医药等资本技术密集型产业集聚为主,中、西段地区则集聚了化学工业、金属加工、食品制造、纺织服装等资本与劳动密集型产业。要加强经济带上中下游开发区之间的多维良性互动,注重绿色发展、创新发展与结构优化,进一步提升其对长江经济带高质量发展的引领与支撑作用。  相似文献   
100.
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