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101.
不同指标下的穗港城市走廊潜在通达性及其空间格局 总被引:9,自引:2,他引:7
本文以最短时间距离以及加权平均出行时间两种指标,其中后者以未来人口数为其加权因子,在对广州至香港之间廊道状区域的陆路交通网络现状通达性数据进行计算的基础上,对其潜在通达性及其空间格局进行预测分析。由此得出,穗港走廊内部的陆路网络潜在通达性呈现出同心环状态分布的空间格局,其潜在通达性水平以环心为最优,逐渐往外层递减;两种指标换算成通达性系数进行对比,发现利用未来人口数作为加权因子之后,走廊南部在整个网络的通达性地位得到了提升,但走廊北部的通达性地位却受到了削弱;穗港走廊潜在通达性空间格局比现状更加收敛,整体通达性水平得到提升,初始通达性水平越低的地方,提升的幅度越大。 相似文献
102.
基于CA与AO的区域土地利用变化模拟研究——以三峡库区为例 总被引:3,自引:0,他引:3
运用元胞自动机(Cellular Automata)与AO(ArcObject) 相结合的方法, 在VB 环境下编程来 进行三峡库区地类变化模拟研究。以1995 年和2005 年的土地利用图为基础数据, 比较研究期各 地类的变化数量与方向以确定地类转换之间的优先级, 然后确定地类的转换概率。研究结果表明 此方法便于理解与操作, 同时模拟精度高; 预测结果说理性强, 其结果显示三峡库区城镇建设用 地增加, 耕地面积减少, 水域的面积在增加。其预测结果可以指导库区的土地利用规划, 为库区有 效土地管理提供参考。 相似文献
103.
Sacit Özdemir Cahit Yeşilyaprak Bahadır Aktuğ Derya Öztürk Deniz Çoker Recep Balbay 《Experimental Astronomy》2018,46(2):323-336
We present preliminary statistics on the precipitable water vapor (PWV) content over the Karakaya Hills in Erzurum city, where the largest optical and near-infrared astronomical telescope in Turkey will be operated. Since the observatory will observe in the near-infrared (NIR), it is intended to perform PWV measurements of the atmosphere above the site by using signal delays in Global Positioning System (GPS) communication. The analysis of the GPS data recorded on the summit for almost one year shows that the atmosphere over the site of the observatory, which has an altitude of 3170 m, has favorable conditions for NIR observations. From GPS measurements, we report that the site had an average PWV of 3.2 mm and a median PWV of 2.7 mm between October 6, 2016, and June 15, 2017. We also present the time dependency of the PWV content and the correlations between the amount of PWV and the other meteorological records gathered from radiosonde flights and ground-based measurements. 相似文献
104.
105.
Argo资料已成为海洋环境和气候变化研究重要的实测资料来源和基础数据支撑。自2007年全球Argo实时海洋观测网建成以来,每年产生的Argo资料稳固增长,数据总量呈现出海量增长趋势,如何实时有效地对Argo数据进行组织管理与信息服务已成为当前Argo资料共享的关键难题。本文针对Argo数据多源异构的时空特性及多元化的信息服务需求,综合运用分布式混合数据库架构,设计了一种适用于全球Argo资料组织管理的弹性扩展云存储模型,建立了基于Matlab的Argo网格化产品高效可视化方法,构建了基于Flex RIA的WebGIS服务框架,并研制了"全球Argo资料共享与服务平台"实例。平台实现了对全球Argo资料的查询浏览、快速下载及可视化分析等功能,并已在中国Argo实时资料中心部署及对外服务。 相似文献
106.
A.?L.?TserklevychEmail author O.?S.?Zayats Ye.?O.?Shylo O.?M.?Shylo 《Kinematics and Physics of Celestial Bodies》2018,34(1):19-36
The computer simulation of the reorientation of the Earth and Mars lithosphere figure has been performed, which due to the dynamic redistribution of masses, allowed to reveal certain regularities of the structure-forming processes. It has been shown that the shape of the lithosphere surface has a different orientation relatively to the geoids’ (aroids) figure. This causes redistribution of masses leading to a strained state of the lithosphere as a result of endogenous and gravitational-rotational forces action in the evolutionary processes of planet’s self-development. The solution of this problem is considered on the example of lithosphere surface heights approximation by a biaxial ellipsoid with seven parameters. The acting horizontal forces in the upper shell of the planet has been calculated, introducing the concept of “evolutionary deviation of the plumb” and assuming that the tangential forces are proportional to the angle, which is defined as the angle between the direction of the plumb line in the past geological epoch and the plumb line direction at a given point. The calculated fields of tangential force vectors show good consistency with the direction of space-time displacement of Earth’s continents and tectonic plates and consistent with the results of the horizontal movements of GNSS stations. This is quite convincing evidence that under the long-term action of vortex rotationalgravitational forces, the lithospheres masses acquire the properties of creep. All this leads to the fact that interacting blocks and plates within the vortex rotational-gravitational model can be interconnected to elastic fields that creates a single planetary geodynamic field that forms the evolutionary state of the geo-environment. 相似文献
107.
The factors required for estimation of the accuracy of the confidence region construction in the problem of asteroid orbit determination are considered. Blunders and large systematic errors occurring in asteroid observations increase the sizes of confidence regions and cause their noticeable shift in the space of determined parameters. We present the factors that, in addition to analysis of discrepancies (O–C), provide an opportunity to estimate the efficiency of screening observations containing gross systematic errors. The developed factors have been tested for efficiency using simulated observations. The observations have been simulated by parameters set by us and assumed true. It is shown how the sizes of systematic errors and the number of observations with these errors influence the results of screening. All calculations have been performed within the Keplerian model of asteroid motion. 相似文献
108.
Ye. V. Zhuleva 《Oceanology》2010,50(1):107-112
The volumes of formed volcanoes are an important indicator of the formation intensity of the ocean floor volcanogenic morphostructure
under different geodynamic conditions. The distribution of the volumes of volcanoes that formed within the oceanic lithosphere
of different geological ages is considered to analyze the spatial and time dynamics of the scopes of the seamount formation.
The greatest volumes of effused rocks concentrate in volcanoes of different heights on the different-age segments of the lithosphere.
The total volumes of volcanogenic substance growing with increasing age and thickness of the lithosphere is caused by the
increasing range of the heights of the formed volcanoes and the growing number of big seamounts. Despite that the volcanic
seamounts formed within the mid-oceanic ridges, on the divergent boundaries of the lithospheric plates and in the transform
faults most often, half of the volcanogenic material was emitted to the earth’s surface during the spreading of the intraplate
volcanism. A leading part in the formation of the volcanogenic morphostructure of the ocean floor belongs to the formation
of big seamounts with heights of 4–6 km and volumes from 1500 to 5100 km3, respectively, in the provinces with ages from 60 to 90 mln years. 相似文献
109.
110.
长江口海域悬浮颗粒有机物的稳定氮同位素分布及其生物地球化学意义 总被引:4,自引:0,他引:4
对2006年2,5,8,11月份长江口海域表层水体中的悬浮颗粒物(SPM)进行稳定氮同位素分析,根据不同季节、不同区域内其1δ5N值的变化研究水体中氮的迁移、转化等生物地球化学过程,揭示其环境行为,从而对该海域的氮循环机制进行探索。研究发现:该海域悬浮颗粒有机物的稳定氮同位素组成(1δ5Np)分布范围较宽,在0.6‰~8.2‰之间,具有明显的时空分布特点,反映了不同程度的陆源输入和氮的生物地球化学过程的影响。口门内,表层水体中1δ5Np的变化主要受长江径流的陆源输入影响,生物地球化学作用影响较弱;最大浑浊带,水体中的悬浮颗粒有机氮受微生物的降解活动影响明显,各季节均存在不同程度的颗粒物分解作用;外海区,陆源输入减弱,悬浮颗粒物的δ15Np值主要受微藻的同化吸收作用以及一定程度的颗粒物分解作用影响。 相似文献