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291.
基于拓扑联动的增量更新方法研究——以地籍数据库为例 总被引:10,自引:5,他引:5
针对GIS数据库的联动更新及其拓扑一致性维护困难的问题,提出一种基于拓扑联动的增量更新方法,其是针对不同目标类型,分析归纳出相应的拓扑联动类型及其细分类型;对不同目标发展根据其语义特点、拓扑一致性约束条件及变化前后目标间的拓扑关系来推断实体变化类型的规则,并以此为基础分析或推断出每种拓扑联动类型中原关联目标和新生目标的变化情况,进而设计和执行相应的更新操作实现数据库的局部联动更新及其拓扑一致性维护.全文以地籍数据库更新为例,将地籍变更分为地块合并、分割、公共边界调整、结点移动、复合分并5种基本联动类型,并对地块合并、分割、公共边界调整进行了细分,共分为17种细分类型;归纳出地块目标的变化类型推断规则,用实际与模拟数据对本文所提出的方法进行实验验证.本文所提出的方法为此类系统的设计与开发提供了一条新的思路. 相似文献
292.
HU BiSong GONG JianHua ZHOU JiePing SUN Jun YANG LiYang XIA Yu Abdoul Nasser IBRAHIM 《中国科学:地球科学(英文版)》2013,(8):1380-1397
For better detecting the spatial-temporal change mode of individual susceptible-infected-symptomatic-treated-recovered epidemic progress and the characteristics of information/material flow in the epidemic spread network between regions,the epidemic spread mechanism of virus input and output was explored based on individuals and spatial regions.Three typical spatial information parameters including working unit/address,onset location and reporting unit were selected and SARS epidemic spread in-out flow in Beijing was defined based on the SARS epidemiological investigation data in China from 2002 to 2003 while its epidemiological characteristics were discussed.Furthermore,by the methods of spatial-temporal statistical analysis and network characteristic analysis,spatial-temporal high-risk hotspots and network structure characteristics of Beijing outer in-out flow were explored,and spatial autocorrelation/heterogeneity,spatial-temporal evolutive rules and structure characteristics of the spread network of Beijing inner in-out flow were comprehensively analyzed.The results show that(1)The outer input flow of SARS epidemic in Beijing concentrated on Shanxi and Guangdong provinces,but the outer output flow was disperse and mainly includes several north provinces such as Guangdong and Shandong.And the control measurement should focus on the early and interim progress of SARS breakout.(2)The inner output cases had significant positive autocorrelative characteristics in the whole studied region,and the high-risk population was young and middle-aged people with ages from 20 to 60 and occupations of medicine and civilian labourer.(3)The downtown districts were main high-risk hotspots of SARS epidemic in Beijing,the northwest suburban districts/counties were secondary high-risk hotspots,and northeast suburban areas were relatively safe.(4)The district/county nodes in inner spread network showed small-world characteristics and information/material flow had notable heterogeneity.The suburban Tongzhou and Changping districts were the underlying high-risk regions,and several suburban districts such as Shunyi and Huairou were the relatively low-risk safe regions as they carried out minority information/material flow.The exploration and analysis based on epidemic spread in-out flow help better detect and discover the potential spatial-temporal evolutive rules and characteristics of SARS epidemic,and provide a more effective theoretical basis for emergency/control measurements and decision-making. 相似文献
293.
2004年1月到5月,METI/JOGMECMH21在日本南部南海海槽实施了天然气水合物的勘探计划,包括钻探、测井和使用DTS/FBG的长期温度监测。从A站位和T站位两个全取心钻孔中采集了约1000个水样,用于分析南海海槽增生楔中天然气水合物的分布和所含液态甲烷的地球化学作用。分析了从沉积岩心中取出的间隙水所含的氯化物,硫酸盐,Na、Ca和Mg离子的浓度。 相似文献
294.
1IntroductionAs an indispensable part of water resource, groundwater plays an important role in ecological environment. Especially in arid and semi-arid area, the changes of groundwater chemistry even determine the ecological process (Ji, 2001; Murgai, 20… 相似文献
295.
296.
ZHOU Zhenhu MAO Jingwen WU Guang LIU Jun OU’YANG Hegen GUANG Tan LI Tiegang CHE Hewei 《《地质学报》英文版》2014,88(Z2):893-893
Please refer to the attachment(s) for more details 相似文献
297.
Bicarbonate Daily Variations in a Karst River: the Carbon Sink Effect of Subaquatic Vegetation Photosynthesis 总被引:7,自引:0,他引:7
Using the Guancun River, an underground stream-fed river, in Rong’an County of Guangxi, China as a case study, the daily biochemical cycle was examined in this paper based on the data collected a weeklong via high resolution data logger monitoring and high-frequency sampling. Furthermore, the loss of inorganic carbon along its flow path was estimated. Results show that chemical components of the groundwater input are quite stable, showing little change extent; while all of the chemical parameters from two downstream monitoring stations show diel variation over the monitoring period, suggesting that plant activity in the river has a strong influence on water chemistry of the river. The comparison of the input fluxes from the groundwater with the output fluxes of HCO3? estimated at the downstream monitoring station during the high-frequency sampling period shows a strong decrease of HCO3?, indicating that the river is losing inorganic carbon along its flow path. The loss is estimated to be about 1,152 mmol/day/m of HCO3? which represent about 94.9 kg/day of inorganic carbon along the 1,350 m section of the Guancun River. It means that HCO3? entering the river from karst underground stream was either consumed by plants or trapped in the authigenic calcite and thus constitutes a natural sink of carbon for the Guancun karst system. 相似文献
298.
The Zedang and Luobusa ophiolites are located in the eastern section of the Yalung Zangbo ophiolite belt,and they share similar geological tectonic setting and age.Thus,an understanding of their origins is very important for discussion of the evolution of the Eastern Tethys Ocean.There is no complete ophiolite assemblage in the Zedang ophiolite.The Zedang ophiolite is mainly composed of mantle peridotite and a suite of volcanic rocks as well as siliceous rocks,with some blocks of olivinepyroxenite.The mantle peridotite mainly consists of Cpx-harzburgite,harzburgite,some lherzolite,and some dunite.A suite of volcanic rocks is mainly composed of caic-aikaline pyroclastic rocks and secondly of tholeiitic pillow lavas,basaltic andesites,and some boninitic rocks with a lower TiO2 content (TiO2 < 0.6%).The pyroclastic rocks have a LREE-enriched REE pattern and a LILE-enriched (compared to HFSE) spider diagram,demonstrating an island-arc origin.The tholeiitic volcanic rock has a LREE-depleted REE pattern and a LILE-depleted (compared to HFSE) spider diagram,indicative of an origin from MORB.The boninitic rock was generated from fore-arc extension.The Luobusa ophiolite consists of mantle peridotite and mafic-ultramaflc cumulate units,without dike swarms and volcanic rocks.The mantle peridotite mainly consists of dunite,harzburgite with low-Opx (Opx < 25%),and harzburgite (Opx > 25%),which can be divided into two facies belts.The upper is a dunite-harzburgite (Opx < 25%) belt,containing many dunite lenses and a large-scale chromite deposit with high Cr203; the lower is a harzburgite (Opx >25%) belt with small amounts of dunite and lherzolite.The Luobusa mantle peridotite exhibits a distinctive vertical zonation of partial melting with high melting in the upper unit and low melting in the lower.Many mantle peridotites are highly depleted,with a characteristic U-shaped REE pattern peculiar to fore-arc peridotite.The Luobusa cumulates are composed of wehrlite and olivine-pyroxenite,of the P-P-G ophiolite series.This study indicates that the Luobusa ophiolite was formed in a fore-arc basin environment on the basis of the occurrence of highly depleted mantle peridotite,a high-Cr2O3 chromite deposit,and cumulates of the P-P-G ophiolite series.We conclude that the evolution of the Eastern Tethys Ocean involved three stages:the initial ocean stage (formation of MORB volcanic rock and dikes),the forearc extension stage (formation of high-Cr203 chromite deposits and P-P-G cumulates),and the islandarc stage (formation of caic-alkaline pyroclastic rocks). 相似文献
299.
正Introduction A 405-cm sediment section GM02 from Gomo Co salt lake in the northern Tibetan Plateau was used to reconstruct climate changes during marine isotope stage(MIS)2,including the Last Glacial Maximum(LGM)and last 相似文献
300.
正As an excellent chemical fertilizer,Potassium Sulphate(K2SO4)could provide both potassium and sulfur elements for crops.However,it is well known that potassium resource is very poor in China.To understand the Crystallization Kinetics(CK)of K2SO4could be conducive to utilize the limited potassium resource,promote the yield and purity of K2SO4.In this study saturated solution of potassium sulphate was prepared according to the phase diagram of Mg2+、 相似文献