月面形貌的3维可视化算法

基于大范围地形可视化算法研究的基础上,对平面geometry clipmaps算法进行改进,利用GPU的顶点着色器实现平面地形向球面地形的投影变换,并综合利用球面视域裁剪、球面视点控制等技术,使geometry clipmaps算法适用于球面海量地形数据的3维可视化;收集处理月球全球影像和形貌高程数据,对算法进行验证,实现月球表面形貌的实时动态3维可视化.试验表明:绘制算法可不受数据量大小的限制、绘制效率高、效果逼真,但存在两极变形较大的缺点.

Abstract：

Based on the study of visualization arithmetic of large area terrain, plane geometry clipmaps algorithm is improved. Projection transformation from plane landform to sphere landform was realized by using GPU vertex shader. In that improved algorithm, methods such as sphere vision field culling and sphere viewpoint control are used.That makes geometry clipmops algorithm more effective in 3D visualization of massive sphere terrain data. The whole moon image and DEM data are collected and disposed, which are used to verify the capability of that algorithm, realizing dynamic and real time 3D visualization of moon surface. The experiments show that the graphic algorithm isn't limited by data quantity, which is of high efficiency and reality simulation, but the two-pole distortion is serious.     

Effect of the dilution process on the attenuation of contaminants in aquifers

This paper discusses the effects of the dilution process on levels of aquifer contamination attenuation, developing analytical equations for application in theoretical and practical cases. The key finding is that, in aquifers, the dilution process causes a reduction of the contaminant concentration. Analytical equations for the assessment of the contaminant attenuation capacity, by means of the dilution process in an aquifer, are put forward. In particular, the attenuation of the contaminant concentration in an aquifer, and thus the dilution, is described by the volumetric flow rate per unit width perpendicular to the flow direction (q _u). Moreover, a classification of q _u was developed, considering six classes of attenuation capacity due to dilution. For the equations validation, nitrate contamination attenuation due to dilution was analysed in two sample areas in Piedmont (North-West Italy). The results confirmed the hypothesis, evidencing high nitrate concentrations in areas with low q _u values, connected to low dilution rate of the contaminant in the groundwater; vice versa, low nitrate concentrations were evidenced in areas with high q _u values, due to a high nitrate dilution rate.     

基于GIS技术的县域城市规划数据管理模式应用的研究——以广东省增城市为例

随着近年来GIS技术在城乡规划方面的应用日趋普及,GIS技术在空间数据采集、数据管理与分析等关键环节上的优势也逐渐显露。同时,县域城市城乡规划数据种类繁杂,数据量大,亟需先进的技术手段对其进行有效组织与管理。采用GIS技术对城乡规划数据进行动态管理和更新将给城乡规划带来极大的便利。本文以广东省增城市规划管理信息系统为案例,系统阐述GIS技术在城乡规划数据管理中的应用。     

世界主要海洋强国综合实力测评研究

文章在回顾世界海洋强国发展历程和分析现阶段发展特点的基础上,构建国家层面的海洋综合实力评价指标体系,并结合层次分析法和加权积决策理论建立了综合实力测评模型。通过选取世界上8个有代表意义的海洋强国,结合其海洋综合实力的现状分析,利用测评模型对其进行测评排序,为我国"海洋强国"战略的科学规划提供参考。     

开发区不同行业工业用地集约利用水平评价——以辽宁省北票开发区为例

以北票开发区为研究对象,通过对不同工业行业进行划分,建立不同行业工业用地土地集约利用水平评价指标体系,应用多因素综合评价模型对开发区内不同行业工业用地集约利用水平进行了测算,揭示其集约利用水平及其差异性,研究结果表明：北票开发区整体工业用地集约利用水平较高,其中纺织业、服装及其他纤维制品制造业和化学原料及化学制品制造业用地集约水平最高,而饮料制造业用地集约利用水平最低。     

北极海冰变化特征分析

本文利用NASA的海冰密集度资料(时间为1978年10月～2002年9月,分辨率为1.0×0.25),计算并分析了1978～2002年的北极海冰面积、范围的时间变化趋势以及变化的空间分布。     

Paleo‐fires and Atmospheric Oxygen Levels in the Latest Permian: Evidence from Maceral Compositions of Coals in Eastern Yunnan,Southern China

Inertinite maceral compositions of the Late Permian coals from three sections in the terrestrial and paralic settings of eastern Yunnan are analyzed in order to reveal the paleo-fire events and the atmospheric oxygen levels in the latest Permian. Although the macerals in the studied sections are generally dominated by vitrinite, the inertinite group makes up a considerable proportion. Its content increases upward from the beginning of the Late Permian to the coal seam near the Permian-Triassic boundary. Based on the microscopic features and the prevailing theory that inertinite is largely a by-product of paleo-fires, we suggest that the increasing upward trend of the inertinite abundance in the latest Permian could imply that the Late Permian peatland had suffered from frequent wildfires. Since ignition and burning depend on sufficient oxygen, a model-based calculation suggests that the O2 levels near the Wuchiapingian/Changhsingian boundary and the Permian-Triassic boundary are 27% and 28% respectively. This output adds supports to other discoveries made in the temporal marine and terrestrial sediments, and challenges the theories advocating hypoxia as a mechanism for the Permian-Triassic boundary crisis.     

山西临汾中心地震台石英摆倾斜仪前驱波特征分析

文章对山西临汾中心地震台石英摆倾斜仪记录到的2008至2009年3月全球MS≥7.0、中国大陆MS≥6.0地震前前驱波进行了统计,结果表明,全球50%的大于7.0级地震震前有前驱波记录,而对于中国大陆大于6.0级地震震前也有前驱波记录;前驱波出现的时间多为震前几小时到7 d左右,存在有形态和幅度的差异,且对应的地震具有地区性的特点.     

基于GIS技术的地质灾害风险分析系统研究

地质灾害的社会经济属性决定了对其规律的研究应有别于传统的工程地质学研究 ,从社会属性方面来分析地质灾害具有更大的社会经济效益。地质灾害的危险性和受威胁对象的易损性是控制地质灾害风险评价的基本条件 ,对这两者的分析评价称作地质灾害危险性评价和社会经济易损性评价。GIS技术支持下的地质灾害风险分析代表着地质灾害研究领域的一个重要发展方向。经过多年研究 ,作者开发出了基于商业GIS软件的区域地质灾害风险分析系统 (RiskAnly)。本文介绍了该系统的设计思路、基本结构和工作过程 ,并利用此系统对我国全国范围的滑坡灾害进行了危险性分析、区域社会经济易损性分析和最终的风险评估。     

内蒙古突泉盆地突D1井中侏罗统万宝组烃源岩地球化学特征

突泉盆地南部的牤牛海凹陷实施的突D1井见到良好的油气发现.钻井烃源岩的地化指标表明：有机质丰度低;有机质类型主要为Ⅲ型,少部分为Ⅱ型;有机质演化进入高成熟阶段,处于生气阶段.指示突D1井中侏罗统万宝组烃源岩具有一定的生烃条件.突泉盆地油气勘探方向应以找气为主.