Cross-scale analysis of cluster correspondence using different operational neighborhoods

Cluster correspondence analysis examines the spatial autocorrelation of multi-location events at the local scale. This paper argues that patterns of cluster correspondence are highly sensitive to the definition of operational neighborhoods that form the spatial units of analysis. A subset of multi-location events is examined for cluster correspondence if they are associated with the same operational neighborhood. This paper discusses the construction of operational neighborhoods for cluster correspondence analysis based on the spatial properties of the underlying zoning system and the scales at which the zones are aggregated into neighborhoods. Impacts of this construction on the degree of cluster correspondence are also analyzed. Empirical analyses of cluster correspondence between paired vehicle theft and recovery locations are conducted on different zoning methods and across a series of geographic scales and the dynamics of cluster correspondence patterns are discussed.      

评价生物气生成量、生成期的元素平衡法及其应用

生物气的生成期对其成藏有至关重要的制约作用,但目前国内外尚缺少可信、有效方法来对此进行评价。针对这一难题,考虑到无论生物气的生成机理如何,都是一个有机元素之间的物质平衡过程,文章探索并建立了评价生物气生成量的元素平衡法,并利用松辽盆地大量的实际分析数据,对这一评价方法(模型)进行了标定和应用。结果表明,松辽盆地生物气的生成可能主要发生在800m以浅的埋深条件下;区内源岩生物气的生成量约为285.0×1012m3;生物气的主要生成期在嫩江组沉积末期之前。     

Macrofaunal Spatial Patterns in Relationship to Environmental Variables in the Richibucto Estuary,New Brunswick,Canada

Estuarine macrobenthos respond to a variety of environmental gradients such as sediment type and salinity, and organic enrichment. A relatively new influence, organic loading from suspended bivalve culture, has the potential to alter this response. A study on soft-bottom macrobenthic communities was carried out in the Richibucto estuary (46°40′N, 64°50′W), New Brunswick, Canada, with samples collected from 18 stations in late September and early October 2006. The site consisted of a large tidal channel originating upstream in a small river. The channel was punctuated by bag culture of oysters along its length. A total of 88 species were recorded. The mean values of abundance, species richness, and diversity (H′) of macrofauna were 11,199 ind. m⁻² (ranged from 4,371 to 19,930 ind. m⁻²), 23.4 species grab⁻¹ and 3.29 grab⁻¹, respectively. In general species richness and H′ increased from the upper estuary to the estuarine mouth. Multivariate analyses clearly exhibited the spatial distribution in community structure, which coincided with the locations along the estuary (the upper, the lower and the mouth), as well as inside and outside the channel. Species richness and diversity H′ showed strong positive correlations with salinity (21.2–25.2 ppt), and abundance was positively correlated with water depth (1.0–4.5 m). Abundance and species richness were negatively correlated with both of silt–clay fraction (3.3–24.8%) and sorting (σ_I). Species richness was also negatively correlated with organic content (1.9–12.7%). The BIO-ENV analyses identified silt–clay fraction, σ_I and salinity as the major environmental variable combination influencing the macrofaunal patterns, and silt–clay fraction as the single best-correlated variable.     

地质勘查项目数据库管理系统的设计与开发

利用地理信息系统(GIS)和数据库管理技术,以安徽省地质勘查项目数据库管理系统为例,设计了系统的逻辑模型和功能结构,并介绍了系统的组成和实现的关键技术.该系统实现了地质勘查项目区的自动矢量化以及查询、统计和分析等管理功能,为地质勘查项目的管理提供了有效的技术手段.     

一种结合整型最佳谱间预测与SPIHT的MODIS影像无损压缩算法

针对MODIS(Moderate Resolution Imaging Spectroradiometer)影像数据海量并具有重要研究价值的特点,研究MODIS影像的无损压缩算法。采用最佳线性预测方法,通过波段相关性排序确定波段最优预测顺序,并自适应计算"预测波段"与"当前波段"的二阶最佳预测器系数,减少谱间冗余;以多级树集合分裂树(Set Partitioning In Hierarchical Trees,SPIHT)编码算法降低谱内相关。为确保无损压缩,对线性预测系数进行最佳逼近取整操作,并采用基于提升格式的D5/3整数小波变换。实验结果表明本文提出的算法在压缩比上性能较3DSPIHT等算法突出。     

南京某深基坑边坡支护设计与施工

南京某深基坑周边环境较为复杂,地下水丰富,基坑开挖较深,最深处达13m。根据周边环境的情况和开挖的深度,采用了钻孔灌注桩和土钉锚杆相结合的支护形式。分析了该基坑施工的技术要点,通过监测结果,说明该支护方案是可行的。     

“多对多”模式GPS台站网系统设计与应用分析

本文在分析GPS RTK定位工作模式的基础上,以苏州市为研究对象,讨论了＂多对多＂模式GPS台站网系统设计,研究了相应的操作规程,并进行了该模式下的定位试验,对定位结果的精度进行了分析,最后给出了结论。     

顾及DEM误差自相关的坡度计算模型精度分析

基于DEM的坡度计算,其误差来源于DEM误差、DEM结构和坡度计算模型。在顾及DEM误差自相关的前提下,对四种DEM坡度计算模型进行了分析和评价。研究表明,三阶不带权差分能给出较高的坡度计算精度;在局部窗口中,格网点数量越多,坡度计算越准确;等权比不等权的坡度计算模型更准确;DEM误差自相关结构形式对坡度计算无影响。进一步的理论分析和试验分析还表明：DEM误差自相关性的存在,不仅能够改善地形分析的精度,也能改善DEM自身精度。     

遥感技术在煤炭资源开发状况监督管理中的应用研究

利用高分辨率遥感图象可以快速查明煤炭资源开发状况以及煤炭资源开发的合法性（界内开采、界外开采、越界开采）等,对煤矿安全生产及维护矿业秩序具有重要意义。以我国中部某煤炭开采密集区为试验区,选择不同分辨率的遥感数据,从矿山铺助设施、道路、矿堆、矸石的特征出发,进行矿山开采状况遥感解译;以地理信息系统技术（GIS）为支撑实现采矿权数据、规划数据图层与遥感专题数据的叠加分析和相关分析,判断非法与越界矿山,评价矿产资源开发与保护规划执行情况。     

Sedimentary characteristics of terrigenous debris at site MD05-2905 in the northeastern part of the South China Sea since 36 ka and evolution of the East Asian monsoon

Sediments with high sedimentation rate at site MD05-2905 in the Northeastern slope of the South China Sea provide unique materials for a high-resolution study on the paleoenvironment. Based on precise dating of AMS ¹⁴C, grain size analysis of terrigenous debris at core MD05-2905 was conducted after organic matter, biological carbonate and biogenic opal were removed. The results show that 15.5–63.5 μm coarse grain size ingredients may indicate East Asian winter monsoon changes and that 2–9 μm fine grain size ingredients may be used as a proxy of evolution of the East Asian summer monsoon. The results of grain size analysis, which suggest East Asian monsoon intensity, reveal that a winter monsoon dominated the glacial regime and a summer monsoon dominated the Holocene regime. It was also shown that the summer monsoon increased gradually, experienced several abrupt changes and reached a culmination in the early Holocene (11200–8500 a B.P.) since 36 ka. Controlled by precession periodicity, it may be related with the amount of solar radiation at the highest stage, which needs further study. __________ Translated from Advances in Earth Science, 2007, 22(10): 1012–1018 [译自: 地球科学进展]