面向灭火救援工作需求的最优路径规划研究     

丁晓春 《测绘与空间地理信息》2013,(8):103-106

分析了目前上海市交通网络状况、道路数据的特点,针对消防地理信息系统的特殊要求,提出针对灭火救援工作需求的最优路径规划解决方案,设计算法并提供Web Service接口以供多方调用,最后实验验证算法有效性。  相似文献   

基于Geo2M的日本电动车运行支援系统的研究与开发     

肖乐斌 《测绘与空间地理信息》2013,(Z1):125-127

介绍了利用Geo2M(SuperMap iServer)云服务对电动车运行进行支援的系统的设计与实现。该系统能够对实测的GPS行走数据进行位置纠偏、推定,能进行速度推算和路径检索并给出电费计算结果,并提供充电信息。  相似文献   

基于度的枝切线优化策略     

张会战  独知行  陶秋香  贾光帅 《测绘科学》2013,38(2):96-97

本文通过对Goldstein枝切算法的研究和分析,针对它的枝切线连接策略中存在的缺陷,采用基于度的最短路径算法改进了枝切线的连接策略,消除了Goldstein枝切线中的圈和贯通枝切线,减少了孤立区域;与Prim算法相比,在兼顾运算效率的条件下有效地改善了解缠结果。  相似文献   

MIGRATION,SENSE OF PLACE,AND NONMETROPOLITAN VITALITY     

《Urban geography》2013,34(1):80-88

Across Europe there is a lively policy and academic debate on what the essential conditions are for the development of new economic activities in city-regions. The focus is on knowledge-intensive and creative industries. Different theories (glocalization, clustering, embeddedness, path dependence, "hard" and "soft" location factors) identify the essential factors. In this article, we review debates and theories on these conditions and specifically focus on the different pathways city-regions follow. This results in a set of hypotheses, which are evaluated with empirical evidence from three city-regions: Amsterdam, Birmingham, and Budapest. In each of these city-regions factors can be identified that inhibit the growth of knowledge-intensive and creative industries as well as enable such development. Rather than moving toward a common type of city-region, it is likely that distinctive economic outcomes will be generated due to strengths and assets inherited from the past.  相似文献   

江苏省经济重心与能源碳排放重心路径演变分析     

李想  王仲智  芦惠 《福建地理》2013,(3):59-64

本研究引入重心模型,采用1998—2008年江苏省经济和能源消费数据,计算出各年份GDP、工业产值、碳排放和人均碳排放的演变路径,从移动方向、移动距离、路径对比和空间相关性多角度阐释了经济重心和碳排放重心的动态变化和空间联系.结果显示:经济重心和碳排放重心总体向东南方向偏移,2006年后出现略微的北移迹象;11年间重心移动距离排序为:碳排放重心(32.1 km)>人均碳排放重心(29.6 km)>GDP重心(14.6 km)>工业产值重心(10.9 km);相较于经济重心而言,碳排放重心的空间位置偏向于省域的西北方向;经济重心和人均碳排放重心在空间上表现为显著正相关关系.  相似文献   

硬壳蛤形态性状与体质量、软体质量及肥满度的相关性和通径分析     

陈雅琦  梁健  郭永军  李永仁 《海洋科学》2022,46(10):122-128

为研究硬壳蛤形态性状对体质量(Y)、软体质量(Y₁)及肥满度(K)的影响,测量硬壳蛤的壳长(X₁)、壳宽(X₂)、壳高(X₃)、体质量(Y)和软体质量(Y₁)等指标,并进行相关性分析、多元回归分析和通径分析。结果表明:体质量变异系数最高,壳宽与体质量相关系数最高(0.970)、壳长与软体质量相关系数最高(0.946)、壳长与肥满度相关系数最高(0.203)。壳宽对体质量直接作用最大(0.145)、壳长对软体质量直接作用最大(1.113)、壳长对肥满度直接作用最大(1.752)。形态性状与体质量、软体质量及肥满度的多元回归方程分别为Y=–46.359+0.288X₁+1.723X₂+0.640X₃,R²=0.949;Y₁=–6.607+0.301X₁+0.157X₂–0.161X₃,R²=0.901;K=3.159+0.173X₁+0.008X₂–0.179X₃,R²=0.072。壳宽是影响硬壳蛤体质量的主要因素,壳长是影响硬壳蛤软体质量的主要因素,各性状与肥满度回归关系不显著,个体间肥满度差异大。研究结果可为硬壳蛤选育及苗种繁育提供参考。  相似文献   

紫贻贝体尺性状和体质量性状对足丝性状的影响分析     

张守都  张伟  李永仁  赵文溪  彭慧婧  邹杰  宋爱环 《海洋科学》2022,46(12):169-176

为研究紫贻贝(Mytilus galloprovincialis)体尺性状和体质量性状对足丝性状的影响, 作者选取山东省青岛市即墨养殖区的紫贻贝为研究对象, 分别测量壳长、壳宽、壳高等3个体尺性状, 全湿质量、软体质量2个体质量性状以及足丝直径和足丝茎直径2个足丝性状, 通过相关性分析、多元回归分析和通径分析等方法分别研究了体尺性状和体质量性状对足丝性状的影响。结果显示: 所有性状间相关系数为0.678~0.892, 性状间相关性达到极显著水平(P < 0.01); 多元回归和通径分析结果显示, 壳高和全湿质量分别对足丝性状的影响最大, 壳高对足丝性状通径系数分别为0.515和0.508, 全湿质量对足丝性状分别为0.417和0.520; 建立了体尺性状、体质量性状对足丝直径和足丝茎直径的回归方程。  相似文献   

Age and P–T conditions of the Gridino‐type eclogite in the Belomorian Province,Russia          下载免费PDF全文

H. L. Yu  L. F. Zhang  C. J. Wei  X. L. Li  J. H. Guo 《Journal of Metamorphic Geology》2017,35(8):855-869

Although eclogites in the Belomorian Province have been regarded as Archean in age and among the oldest in the world, there are also multiple studies that have proposed a Paleoproterozoic age. Here, we present new data for the Gridino‐type eclogites, which occur as boudins and metamorphosed dykes within tonalite–trondhjemite–granodiorite gneisses. Zircon from these eclogites has core and rim structures. The cores display high Th/U ratios (0.18–0.45), negative Eu anomalies and strong enrichment in HREE, and have Neoarchean U–Pb ages of c. 2.70 Ga; they are interpreted to be magmatic in origin. Zircon cores have δ¹⁸O of 5.64–6.07‰ suggesting the possibility of crystallization from evolved mantle‐derived magmas. In contrast, the rims, which include the eclogite facies minerals omphacite and garnet, are characterized by low Th/U ratios (<0.035) and flat HREE patterns, and yield U–Pb ages of c. 1.90 Ga; they are interpreted to be metamorphic in origin. Zircon rims have elevated δ¹⁸O of 6.23–6.80‰, which was acquired during eclogite facies metamorphism. Based on petrography and phase equilibria modelling, we recognize a prograde epidote amphibolite facies mineral assemblage, the peak eclogite facies mineral assemblage and a retrograde high‐P amphibolite facies mineral assemblage. The peak metamorphic conditions of 695–755°C at >18 kbar for the Gridino‐type eclogites suggest an apparent thermal gradient of <39–42°C/kbar for the Lapland–Kola collisional orogeny.  相似文献   

Coupled extrusion of sub‐arc lithospheric mantle and lower crust during orogen collapse: a case study from Fiordland,New Zealand          下载免费PDF全文

T. A. Czertowicz  J. M. Scott  S. Piazolo 《Journal of Metamorphic Geology》2016,34(5):501-524

The Anita Peridotite is a ~20 km long by 1 km wide exhumed fragment of spinel facies sub‐arc lithospheric mantle that is enclosed entirely within the ≤4 km wide ductile Anita Shear Zone, and bounded by quartzofeldspathic lower crustal gneisses in Fiordland, south‐western New Zealand. Deformation textures, grain growth calculations and thermodynamic modelling results indicate the mylonitic peridotite fabric formed during rapid cooling, and therefore likely during extrusion. However, insights into the exhumation process are gained through examination of aluminous garnet‐bearing meta‐sedimentary gneisses also enclosed within the shear zone. P–T calculations indicate that prior to mylonitization the gneisses enclosing the peridotite equilibrated at 675–746 °C in the sillimanite stability field (stage I), before being buried to near the base of thickened arc crust (stage II; ~686 ± 26 °C and 10.7 ± 0.8 kbar). From this point on, the peridotite unit and the quartzofeldspathic rocks share a deformation history involving extensive recrystallization (stage III) within the Anita Shear Zone. Coupled exhumation of these portions of lower crust and upper mantle occurred during regional thinning of over‐thickened lithosphere at c. 104 Ma (U–Pb zircon). Our favoured model for the exhumation process involves heterogeneous transpressive deformation within the translithospheric Anita Shear Zone, which provided a conduit for ductile extrusion through the crust.  相似文献   

Linking thermodynamic modelling,Lu–Hf geochronology and trace elements in garnet: new P–T–t paths from the Sevier hinterland          下载免费PDF全文

A. M. Cruz‐Uribe  T. D. Hoisch  M. L. Wells  J. D. Vervoort  F. K. Mazdab 《Journal of Metamorphic Geology》2015,33(7):763-781

Major element, trace element and Lu–Hf geochronological data from amphibolite facies pelitic schist in the Raft River and Albion Mountains of northwest Utah and southern Idaho indicate that garnet grew during increasing pressure, interpreted to be the result of tectonic burial and crustal thickening during Sevier orogenesis. Garnet growth was interrupted by hiatuses interpreted from discontinuities in major element zonation. Pressure–temperature paths were determined from the pre‐hiatus portions of the garnet chemical zoning profiles and indicate an increase of ~2 kbar and ~50 °C in the western Raft River Mountains. Garnet Lu–Hf dates of 150 ± 1 Ma in the western Raft River Mountains and 138.7 ± 0.7 Ma and 132 ± 5 Ma in the southern Albion Mountains indicate the timing of garnet growth. Lutetium garnet zoning profiles indicate that the Lu–Hf ages are biased towards the post‐hiatus or outer pre‐hiatus segments, indicating that the determined ages likely post‐date the recorded P–T path history or date the tail end of the paths. Crustal thickening associated with Sevier orogenesis in the western Raft River Mountains thus began slightly before 150 ± 1 Ma, in the Late Jurassic. This study shows that integrating P–T paths determined from garnet growth zoning with Lu–Hf garnet geochronology and in situ garnet trace element analyses is an effective approach for interpreting and dating deformation events in orogenic belts.  相似文献