基于SuperMap的空间大数据可视化技术研究与应用     

崔雪  云惟英  周强  冯振华  陈颖  张振琦 《测绘与空间地理信息》2017,40(Z1)

人类正从IT时代走向DT时代,诸多的技术手段使大数据处理技术能够从大规模数据中分析出相关模式或趋势,让我们对海量数据的价值挖掘充满了期待.当可视化呈现让大数据的潜力达到最大时,以往未被观察到的现象或趋势很容易被发现,用户能够快速地获得更多信息,发现他们所需要的价值.因此,如何最大化地呈现大数据中隐含的价值变得尤为关键.本文将重点研究空间大数据的可视化方法,充分发挥数据可视化的作用,帮助用户挖掘隐藏在空间大数据中的价值.  相似文献   

锂光卤石X-ray衍射标准图谱          下载免费PDF全文

阳海棠  曾德文  唐垂云  李凯明  韩海军 《盐湖研究》2016,24(4):32-36

盐湖卤水提锂过程中需了解与掌握锂元素结晶析出与赋存状态,锂光卤石(LiCl·MgCl_2·7H_2O)作为重要的中间产物,其结构与种类均需鉴别,但由于缺乏锂光卤石的X-ray衍射标准图谱,使得常见的Xray衍射方法无法应用。利用相图原理,通过湿固相法制备高纯锂光卤石,然后对其进行X-ray衍射分析,从而提供锂光卤石X-ray衍射的标准图谱,为高镁锂比盐湖卤水提锂过程分析提供可靠的理论支撑。  相似文献   

Stability and capsizing analysis of nonlinear ship rolling in wind and stochastic beam seas     

《Applied Ocean Research》2016

Considering the actual seaway condition, stability and capsizing of nonlinear ship rolling system in stochastic beam seas is of significant importance for voyage safety. Safe zone are defined in the phase space plan of the unperturbed Hamilton system to qualitatively distinguish ship motions as capsize and noncapsize. Capsize events are defined by solutions passing out of the safe zone. The probability of such an occurrence is studied by virtue of the random Melnikov function and the concept of phase space flux. In this paper, besides conventional wave excitation, the effect of wind load is also taken into account. The introduction of wind load will lead to asymmetry, in other words, it transforms the symmetric heteroclinic orbits into asymmetric homoclinic orbits. For asymmetric dynamical system, the orbital analytic solutions and its power spectrum are not readily available, and the technique of discrete time Fourier transformation (DTFT) is used. In the end, as verification of theoretical critical significant wave height, capsizing probability contour diagram is generated by means of numerical simulation. The contour diagram shows that these analytical methods provide reliable and predictive results about the likelihood of a vessel capsizing in a given seaway condition.  相似文献   

中心内缩综合元的水深自动综合模型     

王沫  李树军  金绍华 《测绘科学》2016,41(10):176-180

针对水深自动综合问题,该文在满足水深综合的特殊要求并保持综合前后水深分布空间一致性的基础上,利用Voronoi图工具,采用定性和定量分析方法,建立了相应的综合规则和控制流程,设计了一种中心内缩综合元的水深自动综合模型,并进行了实验验证。实验结果表明,该模型可以在保证水深综合质量的前提下,实现流程的自动化。  相似文献   

Tessellations in GIS: Part II–making changes     

Christopher Gold 《地球空间信息科学学报》2016,19(2):157-167

Abstract

We attempt to describe the role of tessellated models of space within the discipline of Geographic Information Systems (GIS) – a speciality coming largely out of Geography and Land Surveying, where there was a strong need to represent information about the land’s surface within a computer system rather than on the original paper maps. We look at some of the basic operations in GIS, including dynamic and kinetic applications. We examine issues of topology and data structures, and produced a tessellation model that may be widely applied both to traditional “object” and “field” data types. The Part I of this study examined object and field spatial models, the Voronoi extension of objects, and the graphs that express the resulting adjacencies. The required data structures were also briefly described, along with 2D and 3D structures and hierarchical indexing. The importance of graph duality was emphasized. Here, this second paper builds on the structures described in the first, and examines how these may be modified: change may often be associated with either viewpoint or time. Incremental algorithms permit additional point insertion, and applications involving the addition of skeleton points, for map scanning, contour enrichment or watershed delineation and simulation. Dynamic algorithms permit skeleton smoothing, and higher order Voronoi diagram applications, including Sibson interpolation. Kinetic algorithms allow collision detection applications, free-Lagrange flow modeling, and pen movement simulation for map drawing. If desired these methods may be extended to 3D. Based on this framework, it can be argued that tessellation models are fundamental to our understanding and processing of geographical space, and provide a coherent framework for understanding the “space” in which we exist.  相似文献   

Validity of the Sutherland-Lindemann law and melting temperatures in the Earth's interior     

Francesco Mulargia  Francesca Quareni 《Geophysical Journal International》1988,92(2):269-282

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The β Cephei instability strip     

L. Deng  D.R. Xiong 《Monthly notices of the Royal Astronomical Society》2001,327(3):881-887

We carried out a series of linear stability analyses of the radial and low-degree non-radial p modes for stellar models with initial masses of     . The stellar models were computed by using convective overshoot distance     , 0.25 and 0.40  H _P. Our numerical results show that the β Cephei instability strip forms a horn-shaped region pointing upwards near the main sequence on the Hertzsprung–Russell diagram (HRD). The lower part of the instability strip for the radial modes join the zero-age main-sequence (ZAMS) at     , while the top of the instability strip extends up to     . The instability strip for the non-radial modes is even wider. The overall instability strip is dominated by the radial and non-radial fundamental modes. The first overtone (the radial-order index     is also pulsationally unstable. We have shown that the β Cephei stability is almost independent of the overshoot parameter d _over used for the stellar models, while it depends critically on the metal abundance. With decreasing metal abundance, the instability region shrinks and eventually disappears for     .  相似文献   

带相敏检波器的线性可变差动变压器(LVDT)读出电路的设计     

Chen Jin ling 《成都信息工程学院学报》1989,(2)

本文简单介绍了LVDT、相敏检波器和三角波发生器的工作原理及自行设计的一种实用的LVDT相敏检波读出电路。  相似文献   

Properties of iron at the Earth's core conditions   总被引：2，自引：0，他引：2  

Orson L. Anderson 《Geophysical Journal International》1986,84(3):561-579

Summary. The phase diagram of iron up to 330 GPa is solved using the experimental data of static high pressure (up to 11 GPa) and the experimental data of shock wave data (up to 250 GPa). A solution for the highest triple point is found ( P = 280 GPa and T = 5760 K) by imposing the thermodynamic constraints of triple points. This pressure of the triple point is less than the pressure of the inner core–outer core boundary of the Earth. These results indicate that the density of iron at the inner core–outer core boundary pressure is close to 13 g cm⁻³, which lies close to the seismic solutions of the Earth at that pressure. It is thus concluded that the Earth's inner core is very likely to be virtually pure iron in its hexagonal close packed (hcp) phase.
It is shown that four properties of the Earth's inner core determined from seismology are close in value to the corresponding properties of hcp iron at inner core conditions: density, bulk modulus, longitudinal velocity, and Poisson's ratio. The density–pressure profile of hcp iron at inner core conditions matches the density–pressure profile of the inner core as determined by seismic methods, within the spread of values given by recent seismic models.
This indicates that the Earth is slowly cooling, the Earth's inner core is growing by crystallization, and the impurities of the core are concentrated in the outer core. The calculated temperature at the Earth's centre is 6450 K.  相似文献   

    

Peng Yongqing  Zhu Yufeng  Yan Shaojin 《大气科学进展》1994,11(3):277-284

This paper concerns the reconstruction of a dynamic system based on phase space continuation of monthly mean temperature 1D time series and the assumption that the equation for the time-varying evolution of phase-space state variables contains linear and nonlinear quadratic terms, followed by the fitting of the dataset subjected to continuation so as to get, by the least square method, the coefficients of the terms, of which those of greater variance contribution are retained for use. Results show that the obtained low-order system may be used to describe nonlinear properties of the short range climate variation shown by monthly mean temperature series.  相似文献