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91.
92.
裂缝一直是隧道病害的重点检测对象,但传统人工巡检仅能通过肉眼发现后记录,人工识别精准度与效率完全取决于个人经验判断,无信息化手段辅助,作业效率识别精度亟待提升.针对以上问题,本文借助高清工业相机成像分辨率高、采集速度快等特点,将高清工业相机部署于轨道车上获取隧道表面裂缝病害信息,大幅提高了隧道裂缝识别效率,将识别精度提... 相似文献
93.
当前国内外针对产业用地集约节约化利用方面的研究比较少,制约这方面研究的一个重要内容就是缺乏有效的基础数据,本文在分析了产业用地所涉及的相关数据的基础上,结合GPS定位特点,对产业用地数据采集与调查技术进行分析研究。 相似文献
94.
《The Cartographic journal》2013,50(1):30-39
AbstractAt the end of the eighteenth century, a large-scale map of the Austrian Netherlands and the Prince-Bishopric of Liège was manufactured, covering more or less the current territory of Belgium. The work for this Carte de Cabinet was carried out by artillerists under the guidance of count Joseph de Ferraris, who was commissioned for the task by the Habsburg government. At the time that the map was designed, no modern legend was included. This paper tries to fill that gap by presenting a legend that was constructed more systematically than any of its predecessors. It is based on the structure of the legend of the Topographic Map of Belgium and the CORINE land cover map, making it an easy-to-use tool for modern researchers. The problems encountered during the development of the legend are described, and the link between the Carte de Cabinet and eighteenth-century French cartography as well as with cartographic manuals is also discussed. 相似文献
95.
利用工业CT对自然煤岩样进行断层扫描观测。针对煤岩裂隙系统的多尺度、各向异性特征,应用Canny算子图像分割与方向性边缘检测技术,提取煤岩CT图像割理的总体特征、水平方向和垂直方向特征;根据特征图像计算了煤岩样的总体分形维数、孔隙度,各向异性分形维数与孔隙度及其在三维空间中的分布;讨论了分形维数与孔隙度、渗透率之间的关系,并根据煤岩样的分形维数、孔隙度对实际工程岩体的孔隙度和渗透率进行了外推计算。研究表明,煤岩样不同扫描断面的分形维数和孔隙度不同,同一煤样同一断面不同方向的分形维数与孔隙度亦不相同。利用图像分割与边缘检测对工业CT图像进行分析,可以对煤岩的各向异性分形维数与孔隙度在2D与3D空间进行精细描述。 相似文献
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98.
Rachid Ait Akbour Jamaâ Douch Mohamed Hamdani Philippe Schmitz 《Comptes Rendus Geoscience》2002,334(13):981-985
To evaluate the risk of contaminant transport by mobile colloids, it is necessary to understand how colloids and associated pollutants behave during their migration through uncontaminated soil or groundwater. In this study, we investigated the influence of aggregation induced by Ca2+ and trace metals (Pb2+, Cu2+) concentrations on the transport of humic-coated kaolinite colloids through a natural quartz sand at pH=4. Adsorbed divalent cations reduce the colloids surface charge and thereby induce aggregation and deposition in porous media. To cite this article: R. Ait Akbour et al., C. R. Geoscience 334 (2002) 981–985. 相似文献
99.
Sonja Aulbach William L. Griffin Norman J. Pearson Suzanne Y. O’Reilly Buddy J. Doyle 《Contributions to Mineralogy and Petrology》2007,154(4):409-427
Major-element compositions of minerals in peridotite xenoliths from the Lac de Gras kimberlites provide constraints on the
mode of lithosphere formation beneath the central Slave Craton, Canada. Magnesia contents of reconstructed whole rocks correlate
positively with NiO and negatively with CaO contents, consistent with variable partial melt extraction. Alumina and Cr2O3 contents are broadly positively correlated, suggestive of melt depletion in the absence of a Cr–Al phase. Garnet modes are
high at a given Al2O3 content (a proxy for melt depletion), falling about a 7 GPa melt depletion model. These observations, combined with high
olivine Mg# and major-element relationships of FeO-poor peridotites (<7.5 wt%) indicative of melt loss at pressures >3 GPa
(residual FeO content being a sensitive indicator of melt extraction pressure), and similar high pressures of last equilibration
(∼4.2 to 5.8 GPa), provide multiple lines of evidence that the mantle beneath the central Slave Craton has originated as a
residue from high-pressure melting, possibly during plume subcretion. Apparent low melt depletion pressures for high-FeO peridotites
(>7.5 wt%) could suggest formation in an oceanic setting, followed by subduction to their depth of entrainment. However, these
rocks, which are characterised by low SiO2 contents (<43 wt%), are more likely to be the result of post-melting FeO-addition, leading to spuriously low estimates of
melt extraction pressures. They may have reacted with a silica-undersaturated melt that dissolved orthopyroxene, or experienced
olivine injection by crystallising melts. A secular FeO-enrichment of parts of the deep mantle lithosphere is supported by
lower average Mg# in xenolithic olivine (91.7) compared to olivine inclusions in diamond (92.6). 相似文献
100.
Didier Miallier Serge Sanzelle Thierry Pilleyre Gérard Vernet Sarah Brugière Tohru Danhara 《Comptes Rendus Geoscience》2004,336(1):1-8
A trachytic tephra, discovered in the ancient lake of Sarliève, ‘Grande Limagne’, has been dated using the thermoluminescence technique. The obtained age, 16±4 ka (), is older than that of the trachytic volcanoes of the Cha??ne des Puys, the ashes of which have already been locally recognised in the region. Its analysis confirms its originality. In the course of the comparisons made to search for its spring, it appears that the wide-dispersion tephra CF7, beforehand correlated by hypothesis to the Puy de Clierzou, probably originates from the Kilian crater or the Puy de Vasset. To cite this article: D. Miallier et al., C. R. Geoscience 336 (2004). 相似文献