顾及地块时空特点的地籍数据组织及查询   总被引：2，自引：0，他引：2  

常征  陈军  杜道生 《武汉大学学报(信息科学版)》1997,(3)

通过分析地块变更的时空变化过程，总结出具有父子关系的时态地块的空间相交性和时间相接性特点，归纳出查询这种关系的约束条件。利用扩展时空复合模型和元组时区标记，借助于变更地块的约束条件，设计出查询变更地块的时态链算法。  相似文献   

构造机理与地震大形势分析     

夏玉胜  胡爱真  唐燕红 《高原地震》1997,(4)

对全球大震时空特征的分析表明，北南半球大震分布与陆地面积成比例，全球强震活动具有35年的地极移周期，并对一些具有全球活动特征的构造事件进行了机理探讨，最后对大陆西部强震的活动规律．尤其是主体活动区的特点进点了仔细的研究。给出了未来一段时间内的预测结果。  相似文献   

气候噪声和气候系统的分维   总被引：8，自引：0，他引：8       下载免费PDF全文

辛国君 《应用气象学报》1997,8(1):85-91

根据相空间嵌入定理，按照Grassberger和Procaccia提出的计算分数维的方法，利用近百年来南、北半球地面气温资料，估算了气候吸引子的分数维，计算结果表明:气候吸引子的分数维南半球为3.3～3.7，北半球为3.2～3.7。它提供了气候吸引子的自相似结构的基本信息，表明模似气候系统最少需要4个独立变量。另外，还讨论了气候噪声对估算维数的影响。  相似文献   

(Hetero)sexing Space: Gay Men and “Straight” Space in Adelaide,South Australia     

Stewart Kirby  Iain Hay 《The Professional geographer》1997,49(3):295-305

This paper examines gay men's perceptions and experiences of everyday places in Adelaide, South Australia. It illustrates the nature of social space as a heterosexual artifact. The paper also outlines ways in which gay men may contribute to the heterosexualization of space. Many gay men monitor the public and private roles they play for fear of the consequences of “discovery,” and through self-policing and restricted behaviors they may contribute to the spatial supremacy of heterosexuality. Acts of nondisclosure and the adoption of straight sexual facades constrain gay men's social and spatial lives.  相似文献   

Dynamic stochastic estimation of physical variables   总被引：1，自引：0，他引：1  

George Christakos  Vijayanivas R. Raghu 《Mathematical Geology》1996,28(3):341-365

A fundamental problem facing the physical sciences today is analysis of natural variations and mapping of spatiotemporal processes. Detailed maps describing the space/time distribution of groundwater contaminants, atmospheric pollutant deposition processes, rainfall intensity variables, external intermittency functions, etc. are tools whose importance in practical applications cannot be overestimated. Such maps are valuable inputs for numerous applications including, for example, solute transport, storm modeling, turbulent-nonturbulent flow characterization, weather prediction, and human exposure to hazardous substances. The approach considered here uses the spatiotemporal random field theory to study natural space/time variations and derive dynamic stochastic estimates of physical variables. The random field model is constructed in a space/time continuum that explicitly involves both spatial and temporal aspects and provides a rigorous representation of spatiotemporal variabilities and uncertainties. This has considerable advantages as regards analytical investigations of natural processes. The model is used to study natural space/time variations of springwater calcium ion data from the Dyle River catchment area, Belgium. This dataset is characterized by a spatially nonhomogeneous and temporally nonstationary variability that is quantified by random field parameters, such as orders of space/time continuity and random field increments. A rich class of covariance models is determined from the properties of the random field increments. The analysis leads to maps of continuity orders and covariances reflecting space/time calcium ion correlations and trends. Calcium ion estimates and the associated statistical errors are calculated at unmeasured locations/instants over the Dyle region using a space/time kriging algorithm. In practice, the interpretation of the results of the dynamic stochastic analysis should take into consideration the scale effects.  相似文献   

夯扩桩半模夯扩试验及夯扩机理探讨   总被引：6，自引：0，他引：6  

陈荣  俞季民 《岩土力学》1996,17(2):16-22

设计了夯扩桩半模夯扩试验，采用读数显微镜直接测读上体质点位移，获得了不同密度的均匀砂土中砂粒的位移，由此确定土体的位移场和密度场。借鉴魏西克（Ｖｅｓｉｃ）球形孔穴膨胀理论和梅耶霍夫（Ｍｅｙｅｒｈｏｆ）塑性剪切理论，结合模型试验成果，对夯扩机理作了探讨，并定性地提出了夯扩机理模式。  相似文献   

中国区域经济差异变化的空间特征及其政策含义研究   总被引：54，自引：6，他引：54  

覃成林 《地域研究与开发》1998,17(2):36-39

采用了种省区人均国内生产总值与全国平均值的离差和比离两个指标，分别判断１９９０￣１９９５年我国区域经济绝对差异和相对差异变化的空间状态，并进一步阐明了其调控区域经济差异的政策含义。  相似文献   

流体在同心环状空间中流动时的压力损失     

张祝新  程晓新  夏圣强 《吉林大学学报(地球科学版)》1997,(2)

同心环状空间是工程上较常见到的流体流动空间，在此空间中流体流动情况的分析较复杂。工程上对其流动情况的分析常常是引用流体力学中的分析结果，但往往由于对环状空间结构的条件重视不够，引用时很容易出毛病。经过仔细推导分析，指出其应用条件，并有助于对同心环状空间中流体流动时压力损失的分析与计算  相似文献   

Recent Progress and Future Prospects in Solar Physics, and Their Relevance for Planet Earth     

Roger M. Bonnet  Anuschka pauluhn 《Surveys in Geophysics》2004,25(5-6):371-440

Understanding our star, the Sun, is of fundamental interest for life on Earth. In this paper, the status of knowledge in solar physics of roughly two decades ago is summarised, and the most recent developments in this very active field are shown, many of them achieved by means of space based missions. The Sun–Earth connection is described and, finally, an outlook on future solar research is given.  相似文献   

Electron microscopy study of the sakhaite from endogenous borate deposit in Hunan, China     

LIU Xiangwen    YANG Guangming  ZOU Huamin  QU Jing & ZHAO Wenxia . Graduate School  China University of Geosciences  Wuhan  China  . Test Center  China University of Geosciences  Wuhan  China  . Physics  Technology College  Wuhan University  Wuhan  China  . Test Center  Zhongshan University  Guangzhou  China 《中国科学D辑(英文版)》2004,47(3)

Sakhaite was first discovered by Ostrovskaya, Pertsev and Nikitina at Siberia in the former Soviet Union. By using the X-ray diffraction technique, they proved that the crystal system of sakhaite was cubic (a = 1.464 nm), its possible space groups were Fm3m, F432, F43m, Fm3, F23, and its crystal chemical for-mula was Ca48Mg16(CO3)16(BO3)28Cl4(OH)8 4H2O[1]. Chichagov, Simonov and Belov studied the crystal structure of synthetic sakhaite and determined that its space group was F4132, …  相似文献