Spatial distribution of altered minerals in the Gadag Schist Belt (GSB) of Karnataka,Southern India using hyperspectral remote sensing data     

Nisha Rani  Tejpal Singh 《国际地球制图》2017,32(3):225-237

Spatial distribution of altered minerals in rocks and soils in the Gadag Schist Belt (GSB) is carried out using Hyperion data of March 2013. The entire spectral range is processed with emphasis on VNIR (0.4–1.0 μm) and SWIR regions (2.0–2.4 μm). Processing methodology includes Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes correction, minimum noise fraction transformation, spectral feature fitting (SFF) and spectral angle mapper (SAM) in conjunction with spectra collected, using an analytical spectral device spectroradiometer. A total of 155 bands were analysed to identify and map the major altered minerals by studying the absorption bands between the 0.4–1.0-μm and 2.0–2.3-μm wavelength regions. The most important and diagnostic spectral absorption features occur at 0.6–0.7 μm, 0.86 and at 0.9 μm in the VNIR region due to charge transfer of crystal field effect in the transition elements, whereas absorption near 2.1, 2.2, 2.25 and 2.33 μm in the SWIR region is related to the bending and stretching of the bonds in hydrous minerals (Al-OH, Fe-OH and Mg-OH), particularly in clay minerals. SAM and SFF techniques are implemented to identify the minerals present. A score of 0.33–1 was assigned for both SAM and SFF, where a value of 1 indicates the exact mineral type. However, endmember spectra were compared with United States Geological Survey and John Hopkins University spectral libraries for minerals and soils. Five minerals, i.e. kaolinite-5, kaolinite-2, muscovite, haematite, kaosmec and one soil, i.e. greyish brown loam have been identified. Greyish brown loam and kaosmec have been mapped as the major weathering/altered products present in soils and rocks of the GSB. This was followed by haematite and kaolinite. The SAM classifier was then applied on a Hyperion image to produce a mineral map. The dominant lithology of the area included greywacke, argillite and granite gneiss.  相似文献   

Crystal field and covalency of octahedral chromium in natural ^[8](Mg_1?xCa_x) ₃^[6] (Al_0.67Cr_0.33)₂Si₃O₁₂ garnets from upper mantle rocks     

Alexej N. Platonov  Klaus Langer  Stanislav S. Matsyuk 《Physics and Chemistry of Minerals》2008,35(6):331-337

In the course of a thorough study of the influences of the second coordination sphere on the crystal field parameters of the 3d ^N -ions and the character of 3d ^N –O bonds in oxygen based minerals, 19 natural Cr³⁺-bearing (Mg,Ca)-garnets from upper mantle rocks were analysed and studied by electronic absorption spectroscopy, EAS. The garnets had compositions with populations of the ^[8] X-sites by 0.881 ± 0.053 (Ca + Mg) and changing Ca-fractions in the range 0.020 ≤ w _Ca[8] ≤ 0.745, while the ^[6] Y-site fraction was constant with x _Cr³⁺ _[6] = 0.335 ± 0.023. The garnets had colours from deeply violet-red for low Ca-contents (up to x _Ca = 0.28), grey with 0.28 ≤ x _Ca ≤ 0.4 and green with 0.4 ≤ x _Ca. The crystal field parameter of octahedral Cr³⁺ 10Dq decreases strongly on increasing Ca-fraction from 17,850 cm⁻¹ at x _Ca[8] = 0.020 to 16,580 cm⁻¹ at x _Ca[8] = 0.745. The data could be fit with two model which do statistically not differ: (1) two linear functions with a discontinuity close to x _Ca[8] ≈ 0.3, (2) one continuous second order function, The behaviour of the crystal field parameter 10Dq and band widths on changing Ca-contents favour the first model, which is interpreted tentatively by different influences of Ca in the structure above and below x _Ca[8] ≈ 0.3. The covalency of the Cr–O bond as reflected in the behaviour of the nephelauxetic ratio decreases on increasing Ca-contents.  相似文献   

Planning versus youth: Stamping out spatial unruliness in Harare   总被引：1，自引：0，他引：1  

Amin Y. Kamete   《Geoforum》2008,39(5):1721-1733

The paper examines the illegal occupation and use of urban spaces by Harare’s youth and the ensuing tussles with the repressive machinery of the local authority and the nation-state. It analyses efforts by planning to contain rampant spatial unruliness. The paper maps the patterns of official hostile responses to the illegal activities of the youth whose daily routines inevitably entail the disregard of the spatial planning framework as reflected in existing legal and regulatory controls. The analysis reveals the reliance by the urban planning and management system on the use of force and violence, a feat made possible by the mobilisation of the repressive state apparatus. The discussion argues that what comes out in the relationship between the order-imposing planning system and the regulation-flouting youth is a situation that can largely be comprehended by turning to the non-progressive side of planning.  相似文献   

The participation of core stakeholders in the design of,and challenges to,the US Clean Power Plan     

Ramiro Berardo  Federico Holm 《Climate Policy》2018,18(9):1152-1164

We examine the participation of stakeholders in the rule-making process leading to the design of the US Clean Power Plan (CPP), which was the cornerstone regulation developed during the Obama administration to lower GHG emissions from power plants in the US. Using publicly available information, we identify the core stakeholders that participated in the different stages of the rulemaking process, from the early draft of the rule to its publication in final form, and examine variables that could help explain their decisions to litigate, either against or in favour of the final version of the rule. We show that the ‘pro-CPP’ stakeholders were (a) more likely to participate during the early stages of the rule-making process, attending meetings with the Environmental Protection Agency (EPA) staff to discuss rule content, and (b) less likely to get involved during the litigation process. ‘Anti-CPP’ stakeholders, on the other hand, did the opposite, being in general less active during the rulemaking stages, and more active during the litigation stage. However, we also find that the ‘anti-CPP’ stakeholders were more tightly organized as a coalition when compared to the ‘pro-CPP’ stakeholders throughout the process (even in the early stages when they participated less). Our results shed new light on the way advocacy coalitions operate in the climate policy subsystem in the US, and help inform debates about the likelihood of conflict and cooperation across a variety of environmental policy topics.

Key policy insights

• The design of the Clean Power Plan was a long and contentious process in which ‘Pro’ and ‘Anti-CPP’ coalitions operated to support and undermine the rule, respectively.

• ‘Pro-CPP’ stakeholders were more active in meetings organized to discuss the CPP with EPA staff, and in submitting written comments.

• ‘Anti-CPP’ stakeholders were more active during litigation, in response to perceived EPA overreach in designing the rule and negative financial impacts on states’ economies.

• Joint participation by ‘Anti-CPP’ stakeholders in meetings conveyed by the EPA to discuss the potential content of the rule helps explain their joint litigation efforts, which hints at their considerable capacity to self-organize as a coalition throughout the process.

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多重熵Kq和g（λ）谱的研究   总被引：1，自引：0，他引：1  

安镇文  黄玮琼 《地震地磁观测与研究》1998,19(6):45-50

应用分形理论中的多重分形和广义维的推导方法,导出了围绕Ｋ熵附近的涨落谱ｇ（λ）,同时描述了广义熵Ｋｑ和多重动态谱的计算方法,特别是利用实际观测数据探讨地震孕育非线性动力演化过程的复杂性,最后讨论了对地震问题的某些应用。  相似文献   

海拉尔盆地煤及其显微组分的红外漫反射光谱特征   总被引：1，自引：0，他引：1  

黄福堂  冯子辉 《地球化学》1998,27(5):500-506

利用红外漫反射光谱和谱带分离技术,从海拉尔盆地煤及其显微组分的红外漫反射光谱图中,在３１００－２８００ｃｍ＾－１范围内分辨出１２或１３个峰,并确认了结构归属,同时建立了５个反映有机质化学结构组成特征的参数,讨论了煤与显微镜组分的生烃潜能。  相似文献   

Patterns of change in the size spectra of numbers and diversity of the North Sea fish assemblage, as reflected in surveys and models   总被引：5，自引：12，他引：5  

Rice  Jake; Gislason  Henrik 《ICES Journal of Marine Science》1996,53(6):1214-1225

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海浪方向谱的现场观测与分析   总被引：3，自引：0，他引：3  

俞聿修  柳淑学 《海洋工程》1994,(2)

方向谱是海浪的基本性质之一。本文在国内首次采用测波仪阵列法在渤海采油平台上成功地观测到海浪方向谱，给出了当地随波浪成长而变化的方向谱表达式。观测前采用数模和模型试验方法，对阵列的布置型式、测波仪间距和平台等对观测结果的影响，以及现有各种方向谱分析方法的精度等进行了对比分析，为提高观测精度，保证方向谱分析的质量提供了依据。  相似文献   

Tidal and Sub-tidal Current Characteristics in the Kangjin Bay,South Sea,Korea     

Young Jae Ro 《Ocean Science Journal》2007,42(1):19-30

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秦山核电站邻近水域浮游植物的研究   总被引：1，自引：0，他引：1  

朱根海  陆斗定 《海洋学研究》1991,9(2):81-97

1989年4月(春)、7月(夏)、10月(秋)和1990年1月(冬)四个季度月,对秦山核电站邻近水域23个测站的浮游植物进行了生态调查研究。共鉴定浮游植物145种(包括变种和变型),其中硅藻类44属138种,甲藻类2属2种,蓝藻类1属2种,绿藻类1属3种。在这些种类中,海水种72种,半咸水种47种,淡水种26种。测区四季均占优势的种类有中肋骨条藻、琼氏圆筛藻、蛇目圆筛藻和星脐圆筛藻等。浮游植物细胞密度以秋季最高,平均为2587×10~3个/m~3,其次为冬、春两季,平均密度分别为2209×10~3个/m~3和2117×10~3个/m~3;夏季平均密度相对较低,为1047m×10~3个/m~3。测区营养盐含量丰富,通常不成为浮游植物繁殖生长的限制因子。浮游植物的种类组成、数量分布和群落结构的变化,主要取决于降雨、光照等气象条件和海流、温盐等水文化学条件的变化。  相似文献