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111.
Gert W. Wolf 《International journal of geographical information science》2014,28(7):1401-1424
This article demonstrates how the generalisation of topographic surfaces has been formalised by means of graph theory and how this formalised approach has been integrated into an ISO standard that is employed within nanotechnology. By applying concepts from higher-dimensional calculus and topology, it is shown that Morse functions are those mappings that are ideally suited for the formal characterisation of topographic surfaces. Based on this result, a data structure termed weighted surface network is defined that may be applied for both the characterisation and the generalisation of the topological structure of a topographic surface. Hereafter, the focus is laid on specific issues of the standard ISO 25178-2; within this standard change trees, a data structure similar to weighted surface networks, are applied to portray the topological information of topographic surfaces. Furthermore, an approach termed Wolf pruning is used to simplify the change tree, with this pruning method being equivalent to the graph-theoretic contractions by which weighted surface networks can be simplified. Finally, some practical applications of the standard ISO 25178-2 within nanotechnology are discussed. 相似文献
112.
????2004??2008???ICESat???????????????GLA12???????????????????????????????????????仯????????????????????????????????????仯??????????????????????????????3 m??????????????????????仯????????????????????????????????? 相似文献
113.
超强台风"海燕"是2013年最著名的台风。分析中国南海台风模式对"海燕"整个过程的预报,发现模式基本预报出"海燕"的快速穿过菲律宾和登陆越南后北翘东折的移动路径,但也存在一些不足,例如强度预报偏弱。通过高分辨率数值模拟分析了"海燕"的变化机理,发现高层暖心、高中低层一致东风气流是其超强发展和快速西移的主要特征。进一步的模式预报试验中,探讨了模拟技术对提高台风预报水平的影响作用。分析结果表明,准确的模式物理参数化(如边界层、积云对流和地形参数化)和模式初始大气构造等,以及提高模式分辨率有助于提高台风预报水平。 相似文献
114.
115.
青海东昆仑哈日扎多金属矿区构造活动的锆石裂变径迹定年分析 总被引:2,自引:0,他引:2
青海省哈日扎多金属矿区位于东昆仑东段,属东昆中多旋回岩浆弧带,是新的矿产勘查基地,成矿作用主要受NE和NW向两组构造蚀变带控制。本文通过不同类型样品的锆石裂变径迹定年分析,探讨区内的构造活动。所获得的10个样品年龄为116~204 Ma,并由3个组年龄构成,即204~181 Ma,142~168 Ma和116~120 Ma。第1组年龄204~181 Ma反映印支晚期三叠纪末羌塘地块与昆仑地块碰撞的地质事件及其时限;后两组年龄主要是晚侏罗世~早白垩世冈底斯地体向北与羌塘地体碰撞汇聚的响应,活动时限为168~116 Ma。第2和3组年龄同时表明本区燕山期构造活动存在强度差异,即有两个强作用期。同时,3组年龄也揭示本区具有多期次成矿活动。 相似文献
116.
Structure,Timing, and Mechanism of the Pliocene and Late Miocene Uplift Process of the Ailao Shan-Diancang Shan,SE Tibet,China 总被引:2,自引:0,他引:2
The uplift of the Ailao Shan-Diancang Shan(ASDS) along the Ailao Shan-Red River(ASRR) shear zone is an important geological event in the southeastern margin of Qinghai-Tibet Plateau tectonic domain in the Late Cenozoic,and it preserves important information on the structures,exhumational history and tectonic evolution of the ASRR shear zone.The uplift structural mode and uplift timing of the ASDS is currently an important scientific topic for understanding the ASDS formation and late stage movements and evolution of the ASRR shear zone.The formation of the ASDS has been widely considered to be the consequence of the strike-slip movements of the ASRR shear zone.However,the shaping of geomorphic units is generally direct results of the latest tectonic activities.In this study,we investigated the timing and uplift structural mechanism of the ASDS and provided the following lines of supportive evidence.Firstly,the primary tectonic foliation of the ASDS shows significant characteristic variations,with steeply dipping tectonic foliation developed on the east side of the ASDS and the relatively horizontal foliation on the west side.Secondly,from northeast to southwest direction,the deformation and metamorphism gradually weakened and this zone can be further divided into three different metamorphic degree belts.Thirdly,the contact relationship between the ASDS and the Chuxiong basin-Erhai lake is a normal fault contact which can be found on the east side of the ASDS.40Ar/39 Argeochronology suggests that the Diancang Shan had experienced a fast cooling event during 3–4 Ma.The apatite fission track testing method gives the age of 6.6–10.7 Ma in the Diancang Shan and 4.6–8.4 Ma in the Ailao Shan,respectively.Therefore the uplift of the ASDS can be explained by tilted block mode in which the east side was uplifted much higher than the west side,and it is not main reason of the shearing movements of the ASRR shear zone.The most recent uplift stages of the ASDS happened in the Pliocene(3–4 Ma) and Late Miocene(6–10 Ma). 相似文献
117.
118.
针对国内某轨检小车研发项目,采用模块化的程序设计集成开发环境Microsoft Visual Studio.NET,开发出了一套功能完善的高速铁路轨道检测控制系统。该系统以高速铁路精密定轨测量原理方法为基础,采用模块化的程序设计思路,实现了轨道检测数据的自动采集、自动记录、自动数据分析和平差处理、成果显示和自动检核等功能。工程应用实践表明,该检测系统运行稳定可靠,检测精度高,具有一定的实用性和推广价值。 相似文献
119.
Apatite fission track analysis and vitrinite reflectance data from outcrop and well samples in the Hodgkinson Province and Laura Basin reveal regional Cretaceous cooling. Apatite fission track analysis appears to define two discrete cooling episodes, in the mid‐Cretaceous (110–100 Ma) and Late Cretaceous (80–70 Ma), although in most samples data allow only definition of a single episode. Rocks now at outcrop cooled from Cretaceous palaeotemperatures generally between 50 and 130°C in the south of the region, and from >100°C in the north. Some samples from the Hodgkinson Province also show evidence for an Early Jurassic cooling episode, characterised by maximum palaeotemperatures varying from at least 95°C (from apatite fission track analysis) to ~200–220°C (from vitrinite reflectance), with cooling beginning at around 200 Ma. Apatite fission track analysis data do not reveal the earlier event in the Laura Basin, but on the basis of vitrinite reflectance data from Permian? units this event is also inferred to have affected the pre‐Jurassic basin units in this region. The regional extent of the Cretaceous cooling episode in the Hodgkinson Province suggests that the elevated palaeotemperatures in this region were most likely due to greater depth of burial, with subsequent cooling due to kilometre‐scale denudation. For a palaeogeothermal gradient of 30°C/km and a palaeosurface temperature of 25°C the total degree of Cretaceous cooling experienced by the samples corresponds to removal of between ~0.8 and >3.0 km of Triassic and younger section removed by denudation, beginning some time between ca 110 and 80 Ma. Higher palaeogradients would require correspondingly lower amounts of removed section. The geology of the Laura Basin suggests that an explanation of the observed Cretaceous palaeotemperatures in this region in terms of deeper burial may be untenable. Heating due to hot fluid flow may be a more realistic mechanism for producing the observed Cretaceous palaeothermal effects in the Laura Basin. 相似文献
120.
解析法是摄影测量学、数字摄影测量与遥感影像纠正处理的基础理论和基本数学模型。通过多年的教学实践,总结出了解析法摄影测量基础理论教学的两条主线,从而有效地帮助学生在学习这门课程时从其繁杂的知识体系中理清思路,找到掌握摄影测量解析法的一条捷径。 相似文献