热水沉积成矿的主要控制因素及识别标志

热水沉积成矿的基本要点可以归纳为:古陆边缘,地壳受热、变薄、拉张、裂陷和迅速下沉,矿床定位于三级边缘成矿盆地中;同生断裂对导矿容矿有明显的控制作用;硅质建造与成矿关系密切;有层状矿体层纹状矿石的热水沉积成因和网脉状矿体角砾状矿石的同生-准同生交代成因;成矿热液中的金属物质主要来源于古老剥蚀区和先期盆地沉积物。在上述基础上,总结了热水沉积成矿的10条识别标志。     

Somaliland: Dynamics of internal legitimacy and (lack of) external sovereignty

Despite its strong legal and historical claims to sovereignty, the Republic of Somaliland remains entirely unrecognized by the international community more than 20 years after it proclaimed independence from Somalia in 1991. Paradoxically, Somaliland’s lack of external legitimacy has, in some ways, facilitated the growth and development of its internal legitimacy. In contrast, Somalia enjoys widespread external recognition from the international community but has very little domestic legitimacy and largely fails to govern effectively the territory it claims. Somaliland’s high degree of domestic legitimacy and its strong desire for external recognition increasingly come into conflict with one another both in the eastern parts of Somaliland and in the continued democratic development of its hybrid domestic political institutions. The safest prediction for Somaliland is continued de facto statehood where its strong internal legitimacy enables it to survive in a hostile external environment but fails to translate into widespread sovereign recognition of its significant domestic accomplishments. Ultimately, though, Somaliland’s ability to deliver the “goods” on economic development and poverty reduction for its citizens will be significantly hampered without external recognition of its domestic achievements.     

对北洺河铁矿水文地质条件的再认识

通过对北洺河铁矿长期疏干排水条件下,水文地质条件现状的研究,更为准确地指导矿山防治水,并为矿山安全生产提出合理的建议。     

Assembling Birrarung Wilam: a case study of Indigenous public artwork in the city

ABSTRACT

Indigenous public artworks in Australian urban spaces have challenged assumptions of Indigenous absence from the city. This paper examines the construction of Birrarung Wilam, in central Melbourne, in the period 2005–2008. We use archival documents and semi-structured interviews to analyse the collaborations between Indigenous and non-Indigenous participants in a project sponsored by the city. We show the particular mediating contribution of ‘fabricators’: a group of commissioned workers and tradespeople with material-specific expertise. Person to person encounters occurred through the modules of project management, with limited scope for long-term engagement. Despite being embedded in formal state-based recognition, Birrarung Wilam asserts Indigenous self-recognition through the renewal and adaptation of Indigenous material practices and traditions and the refusal to provide straightforward interpretive materials at the site. The study provides support for arguments that challenge a simple binary of co-option and resistance in interpreting such public art practice.     

From ‘criminals of the earth’ to ‘stewards of the environment’: The social and environmental justice of Fair Trade gold

The recent emergence of the Fairtrade certification of gold in Latin America and sub-Saharan Africa promises a radical new direction for the environmental governance of artisanal and small-scale mining (ASM). In doing so, it aims to tackle the longstanding environment and development challenges of the sector which mainstream policy has failed to alleviate. The move towards more responsible ASM practices is premised on the strategic deployment of a Fair Trade discourse that argues for its operators to be recognized not as criminals, but as valued and formalized parts of their broader economies. It is argued in this paper that this development intervention should be read within a social and environmental justice framework, one which directly answers the call from political geography for ‘compelling accounts’ of positive representations of the sector.Through a discourse analysis of 10 years of media reports, interviews and recorded life histories of key ASM and Fair Trade stakeholders in Tanzania, it shows how three strands of justice (conceptualized in terms of fairer distribution, procedure and recognition) are articulated by the Fair Trade gold movement and critically assesses the politics behind such a deliberate strategy. In particular, it argues that recognition is a key part of justice that has been underplayed by erstwhile analyses of Fair Trade. Through a case study of Tanzania, it is concluded that although significant progress has been made in terms of arguing for greater recognition for ASM operators, there remains a need to better link discourse with practice in establishing greater distributional justice.     

古土壤的类型及识别标志

古土壤是近年来沉积学研究领域的一个热点。在对古土壤的识别、类型划分、研究方法及研究意义分析介绍的基础上,重点论述了古土壤的宏观和微观结构特征以及矿物和地球化学特征。最后对河北南部晚古生代地层中的古土壤类型进行了初步分析,提出了古土壤研究中需要进一步加强的几个方面的问题。     

用最大似然法进行波场分解和震相识别

本文以介质中弹性波场的传播特征和多元统计分析为基础,从数学上进行严格的推导,得到了模型与资料拟合的最大似然判据,以检验地震波列中是否存在某种特殊波型的能量。利用概率滤波可得分解后的地震图,从图中可以直接得到震相到时。用此方法处理P波资料,效果较好。对于剪切波资料,有时处理结果不十分理想。这可能是由于径向分量和横向分量之间的线性相关性造成的。对于因介质各向异性而形成的分裂剪切波,用此方法得到的S波到时为快S波到时。此方法对于单台三分向记录资料的处理是十分有效的。     

多元隶属函数在雹云识别中的应用

为了探索建立多元隶属函数识别雹云的判别方程，本文将雹云和非雹云视作含参变量β的多因子线性模型，用最小二乘法确定参变量，并构造由多元隶属函数表示的判别方程，进而按样本的多元隶属度回报拟合最好原则确定雹云和非雹云的判别阈值λ０。用该方法建立了５个不同样本组合的雹云判别式，进行了效果检验，并与其它雹云判别法的结果相比较，效果较理想。     

灰色系统理论在航空像片模式识别中的应用

本文根据灰色系统理论,应用关联序分析,探讨了一种对航空像片进行林分类型识别的方法.该方法首先确定航空像片样区信息中反映林分类型空间分布结构特征的频谱光电流数据序列,然后确定标准识别对象频谱序列的模式,再根据关联序分析法计算待识别对象与标准识别对象间的关联程度,从而根据关联度的大小确定待识别对象的林分类型。     

陆地卫星MSS图像地表水域信息的机助识别提取

本文介绍了一种利用陆地卫星MSS图像进行水域信息机助识别提取的快速、经济而有效的方法。该方法以对水与非水信息的光谱特征,比值图像的数据结构特点和大气校正的研究与分析为基础。 研究表明,水与非水的主要差异集中于MSS4与MSS7波段,这两个波段的比值图像可在压抑阴影的同时将两图像的信息集中于一。根据对比值图像数据特点的分析,发现比值图像在作等比例拉伸并取整时所不可避免的信息损失主要集中在低值区,高值区则相对得到扩展增强。由于在MSS4/MSS7图像中,水的信息位于高值区,因此其水域识别能力优于MSS7/MSS4。但是,即使MSS4/MSS7图像也无法完全排除山区深阴影对水域识别的干扰。在进行MSS4/MSS7比值运算之前,首先对MSS4图像作粗略的大气校正,则可圆满地解决这一难题。在经大气校正后的MSS4/MSS7图像上,水体像元的值大于1,而深阴影及其它所有非水信息像元的值则小于1,因此,只要以此为门限值将图像二值化,即可获得精度很高的水域识别图像。完全消除阴影和其它因素的干扰。 本方法运算简单,处理速度为最小距离分类的3倍以上,且精度比分类方法高。它不仅适用于MSS图像,也适用于TM图像。采用本方法进行湖北省地表水域机助识别和面积测量的实际应用表明,在各种地貌类型区内本方法均能以较高的精度完成