网络大数据下的中国现代食甜习惯空间分布特征及其影响因素研究     

姚可桢  岳书平 《地球信息科学学报》2020,22(6):1202-1215

饮食地理文化作为地域文化中最具地方特色的重要元素,在现代人口大规模流动背景下呈现出全新的多样化局面,而基于传统认知的“南甜北咸”的地域分异已然不能代表中国现代食甜分布的空间特征。因此,本文采用网络爬虫技术,获取我国大陆31个省会城市共计约2000万条美食消费数据,从传统类菜品、主食类菜品、饮料类和甜品类菜品4个方面计算城市食甜度,在ArcGIS、MySQL软件支持下,借助GIS空间分析和数理统计方法探究我国现代食甜习惯的空间分布特征,分析影响食甜分布的因素。研究发现：① 中国食甜在空间分布上存在显著的地域分异特征,聚类分析评价参数R ²高达0.88,现代食甜习惯总体呈现“东高北中,西微内低”的包围式格局;② 从整体抑或局部角度,在1%显著性水平上莫兰指数均为正,中国食甜分布呈现显著的空间正相关关系,形成特色鲜明的3个地理集聚区,即以苏浙沪闽为主的东南沿海高甜集聚区,以渝黔川为主的西南内陆低甜集聚区和以陕宁为主的西北内陆低甜集聚区;③ 构建了中国现代食甜习惯分布影响因素模型,其拟合精度为0.82,分析结果显示降水、湿度、气温等气象要素及地理位置是影响现代我国食甜空间分布的重要因素。  相似文献   

An analytical study on three‐dimensional versus two‐dimensional water table‐induced flow patterns in a Tóthian basin          下载免费PDF全文

Jun‐Zhi Wang  Xiao‐Wei Jiang  Zhi‐Yuan Zhang  Li Wan  Xu‐Sheng Wang  Hailong Li 《水文研究》2017,31(22):4006-4018

Although it has been increasingly acknowledged that groundwater flow pattern is complicated in the three‐dimensional (3‐D) domain, two‐dimensional (2‐D) water table‐induced flow models are still widely used to delineate basin‐scale groundwater circulation. However, the validity of 2‐D cross‐sectional flow field induced by water table has been seldom examined. Here, we derive the analytical solution of 3‐D water table‐induced hydraulic head in a Tóthian basin and then examine the validity of 2‐D cross‐sectional models by comparing the flow fields of selected cross sections calculated by the 2‐D cross‐sectional model with those by the 3‐D model, which represents the “true” cases. For cross sections in the recharge or discharge area of the 3‐D basin, even if head difference is not significant, the 2‐D cross‐sectional models result in flow patterns absolutely different from the true ones. For the cross section following the principal direction of groundwater flow, although 2‐D cross‐sectional models would overestimate the penetrating depth of local flow systems and underestimate the recharge/discharge flux, the flow pattern from the cross‐sectional model is similar to the true one and could be close enough to the true one by adjusting the decay exponent and anisotropy ratio of permeability. Consequently, to determine whether a 2‐D cross‐sectional model is applicable, a comparison of hydraulic head difference between 2‐D and 3‐D solutions is not enough. Instead, the similarity of flow pattern should be considered to determine whether a cross‐sectional model is applicable. This study improves understanding of groundwater flow induced by more natural water table undulations in the 3‐D domain and the limitations of 2‐D models accounting for cross‐sectional water table undulation only.  相似文献   

基于航测的三维建模方法研究     

张慧  全威 《测绘与空间地理信息》2016,(12)

随着“数字城市”项目在各大城市如火如荼地发展,城市景观重建是数字城市发展的首要步骤和重要内容。本文结合实际生产项目,对基于航测的三维建模方法进行研究。航测法三维建模通过立体采集建筑物平面几何高程数据,并结合测区DEM成果、影像数据等,使用Dibud软件自动生成三维模型,然后,使用3DMAX软件参考外业采集照片精细修模,给模型贴图等。  相似文献   

三稀矿产资源新兴产业发展及政策建议     

周园园 《地质论评》2016,62(S1):13-14

三稀矿产资源是战略性新兴产业发展的基础原料,广泛应用在国防、航天、高端电子设备、核工业、发光材料等高精尖技术领域。本文在系统收集国内外三稀矿产资源生产、消费领域、价格以及进出口资料的基础上,提出了促进三稀矿产资源新兴产业发展的政策建议  相似文献   

Effects of low- to high-angle normal faults on sedimentary architectures in the Eocene Wenchang Formation,Enping Sag,Pearl River Mouth Basin,South China Sea     

Q. H. Liu  Y. Shu  X. M. Zhu  X. H. Yang  M. Tan 《Australian Journal of Earth Sciences》2016,63(7):903-922

The effects of low- to high-angle (>30°) normal faults on sedimentary architectural units in the Eocene Wenchang Formation, Enping Sag, Pearl River Mouth Basin (PRMB), South China Sea were investigated utilising a high-quality 3D seismic data set and restored paleogeomorphology. It has been shown that sequence stratigraphic units and sedimentary architecture are significantly controlled by the low- to high-angle normal faults. The Wenchang Formation, a second-order sequence, can be subdivided into two para-second-sequences (the Lower and Upper Wenchang sequences, E₂W^L and E₂W^U) and seven third-order sequences (from base to top: SQ1～SQ7). The low-angle fault confined sequence architecture of the Wenchang Formation is mainly characterised by lateral stacking with the ratio of the vertical subsidence (V) to horizontal slip (H) being reduced from 1/2 for E₂W^L to 1/6 for E₂W^U. In contrast, the high-angle fault confined sequence is characterised by vertical stacking with the ratio of V/H close to 1 for sequences SQ1 to SQ7. In the 3D seismic area, the features of sediment-dispersal pattern were interpreted based on an integrated analysis of paleogeomorphology, seismic reflection characteristics, stratal thickness distribution and multiple attribute clustering. The results show that the large-scale fan delta, belt-shape lacustrine deposit and bird-foot braided delta systems mainly developed in the low-angle fault confined sequences, whereas small-scale fan delta, rhombus-shaped lacustrine deposit and lobe-shaped braided delta systems inherited tectono-sedimentary architectures in the high-angle fault confined sequences.  相似文献   

The Mesozoic structural evolution of the Gorgon Platform,North Carnarvon Basin,Australia     

X.-M. Yang 《Australian Journal of Earth Sciences》2016,63(6):755-770

The Gorgon Platform is located on the southeastern edge of the Exmouth Plateau in the North Carnarvon Basin, North West Shelf, Australia. A structural analysis using three-dimensional (3D) seismic data has revealed four major sets of extensional faults, namely, (1) the Exmouth Plateau extensional fault system, (2) the basin bounding fault system (Exmouth Plateau–Gorgon Platform Boundary Fault), (3) an intra-rift fault system in the graben between the Exmouth Plateau and the Gorgon Platform and (4) an intra-rift fault system within the graben between the Exmouth Plateau and the Exmouth Sub-basin. Fault throw-length analyses imply that the initial fault segments, which formed the Exmouth Plateau–Gorgon Platform Boundary Fault (EG Boundary Fault), were subsequently connected vertically and laterally by both soft- and hard-linked structures. These major extensional fault systems were controlled by three different extensional events during the Early and Middle Jurassic, Late Jurassic and Early Cretaceous, and illustrate the strong role of structural inheritance in determining fault orientation and linkage. The Lower and Middle Jurassic and Upper Jurassic to Lower Cretaceous syn-kinematic sequences are separated by unconformities.  相似文献   

非匀一冠层热辐射方向性3维模型构建——以玉米冠层为例     

马红章  刘素美  孙根云  杜永明  孙林  柳钦火 《遥感学报》2016,20(3):374-381

建立适用于多类型植被场景的热辐射方向性模型是进行地表热辐射方向性研究的一种手段。利用真实植株几何及生理参数的统计平均值来刻画理念植株,并给定其空间分布特征,进行不同生长期植被冠层的描述。基于冠层双向孔隙率思想构建了冠层热辐射方向性3维模型,模型继承了孔隙率模型在计算冠层热辐射方向性上的简洁优势同时以几何光学的思想考虑了冠层空间异质性对冠层热辐射方向性的影响。以玉米冠层为例,进行了不同生长期玉米冠层热辐射方向亮温的模拟,通过与实地测量数据的比对表明,本文发展的模型能够较准确地模拟不同生长期玉米植被场景的方向亮温变化规律,模拟误差主要来自理念株的刻画误差、玉米叶片形状的近似以及忽略了多次散射贡献等3个方面。模型的构建方法对稀疏植被场景、浓密植被场景、多类型植被的混合场景均可适用,不同观测几何下的植被场景4组份面积比计算结果有望应用于复杂地表条件下地表返照率的研究。  相似文献   

Evaluating urban public facilities of Shenzhen by application of open source data     

Miaoxi Zhao  Gaofeng Xu  Yun Li 《地球空间信息科学学报》2016,19(2):129-139

Abstract

This article applies open source data of public facilities through data mining, not only to evaluate the public facilities from an objective dimension, but also to reflect the sensory opinions of the group factually, eventually realizing the evaluation measurement of urban public facilities. The research takes Shenzhen city as an empirical case and chooses typical public facilities to mine data, resolve address and weight to explore the application of public facilities evaluation under dimension reduction of open source data. The empirical study consists of three parts. First, as the objective evaluation, we estimate the density distribution and per capita of public facility through data mining and address resolution. Second, as the subjective evaluation, we carry on the location analysis to high-score public facility through attention and satisfaction data of Internet evaluation. Finally, as mentioned above, we calculate the weight of objective and subjective evaluation of public facility, eventually formatting the comprehensive evaluation of public facilities.  相似文献   

荆江三口分流变化及三峡水库蓄水影响          下载免费PDF全文

朱玲玲  许全喜  戴明龙 《水科学进展》2016,27(6):822-831

长江中游荆江的水沙通过三口洪道分流入洞庭湖,三口分流是荆江-洞庭湖关系调整的驱动因子,为揭示其变化特征及三峡工程运用的影响,基于大量的原观数据,系统研究了近60年三口分流比的变化过程,提出其显著调整特征及诱发因素,引入径流还原计算方法,量化了三峡水库不同运用方式对三口分流量的影响幅度。结果表明:①特大洪水及重大人类活动等诱发因素作用下,三口分流比出现4~5年持续性减小的趋势调整期,之后进入分流比稳定恢复的平衡调整期;②2003-2014年,三峡水库汛前枯水补偿调度使得三口分流量年均增加8.000亿m3,汛后蓄水使得三口分流量年均减小29.00亿m3,对三口分流综合影响量为年均减少21.00亿m3,占同期三口年均分流量的4.29%。  相似文献   

三维高密度电阻率法在堤坝工程中的模拟试验     

张汝凯  张晓培  吕守航  陈兵兵  王杰 《世界地质》2016,35(4):1133-1137

为检测堤坝中裂隙、洞穴及渗漏层等隐患的存在,利用三维高密度电阻率法对数字模型和物理模型建立的裂隙隐患进行探测,结果表明室内建立的物理模型在立体图和分层切片图中裂隙的形态有些变化,但其分布范围、位置与相对各自模型中实际的比例尺寸相差不大,说明数值模拟得出的结论可以为实际工程进行理论指导,具有一定的参考价值。  相似文献