地磁感应电流研究综述

因太阳活动而引起的地磁扰动,会在地球表面感生出地电场,从而在地表附近的导体系统中产生地磁感应电流(GICs).太阳表面的异常活动而引起的磁暴会导致强烈的GICs,严重威胁电信设备、电网、油气管道和铁路运输网络等基础设施系统的安全运行,已经成为最严重的空间天气灾害之一.因此,对GICs进行深入研究以建立对其做出迅速预测的能力,在科学和应用方面都有重要意义.本文综述了GICs的研究进展,从引入空间天气的概念开始,将GICs作为从太阳活动到太阳风再到地球扰动的空间天气链的最终环节;重点阐述了GICs的计算中所涉及的三个步骤:地球表面地磁场重建、感应地电场的计算,以及地面导体系统中GICs计算;对每一步骤中主要方法的相关原理和应用做了简要介绍与评估;最后总结了当前GICs的研究现状,并对未来GICs的研究方向与挑战进行了展望.     

塔中北斜坡鹰山组碳酸盐岩溶蚀的模拟实验研究

为了研究碳酸盐岩的微观溶蚀机理,本文采用溶蚀实验和镜像观察的方法,研究了塔中北斜坡鹰山组3种类型碳酸盐岩的溶蚀过程及微观溶蚀特征。结果表明:在相同实验条件下,亮晶生屑灰岩、云质灰岩和泥晶颗粒灰岩的溶蚀量基本一致。由于对物质成分和岩石微结构的选择性溶蚀,它们的微观溶蚀特征存在明显差异。亮晶生屑灰岩和泥晶颗粒灰岩样表面整体被溶蚀降低。云质灰岩样表面方解石部分整体被溶蚀降低,形成铸模孔,白云石溶蚀成蜂窝状溶蚀孔,并突出岩石表面,白云石晶间缝溶蚀加大且相互连通,这对油、气和地下水储渗具有重要意义。      

The Experiments Onboard the ROSETTA Lander

As a part of ESA's cornerstone mission ``ROSETTA' to comet 46P/Wirtanen a 100 kgLander will bring a scientific payload of almost 27 kg to the surface of the nucleus.After a first scientific sequence it will operate for a considerable fraction of thecometary orbit around the sun (between 3 AU and 2 AU). Ten experiments with a number of sub-experiments are foreseen; this paper presents the current status of the Lander development and reviews the scientific capabilities of each of the experiments at a time when the Flight Model (FM) of the Lander is already delivered.     

巢湖蓝藻水华藻胆蛋白的分离与鉴定

在高温季节,巢湖等国内淡水湖中蓝藻大量繁殖常形成蓝藻湖靛(主要由微囊藻组成),它含有丰富的蛋白质、氨基酸、脂肪等营养成分.本文对微囊藻中氨基酸的组成及含量进行了测试,并从其中提取、分离纯化了藻胆蛋白(指其中的藻蓝蛋白和别藻蓝蛋白),最后运用紫外可见光谱对其进行了检测,取得了较为满意的结果.这也为进一步开发利用巢湖湖靛提供了依据。     

分层递阶近似空间下的GIS属性数据不确定性描述

GIS属性数据作为GIS实体的属性,具有模糊性、不确定性。由GIS实体对象和对象的属性组成的二元关系满足近似空间的特性。本研究从GIS信息系统的对象、属性出发,利用格概念,认为GIS属性数据集合可以构成偏序关系,并且(P(A),)构成一个完备的偏序格。如果从属性链的角度分析,GIS实体集在的细分划分空间关系下,可以构成分层递阶近似空间,并且随着属性个数的增加,知识颗粒将逐渐细化。     

An Urban Open Space Extraction Method： Combining Spectral and Geometric Characteristics

This paper introduces an advanced method based on remote sensing and Geographic Information System for urban open space extraction combining spectral and geometric characteristics. From both semantic and remote sensing perspectives, a hybrid hierarchy structure and class organization of open space are issues and mapped from one to another. Based on per-pixel and segmentation mechanism separately, two classification approaches are performed. Owing to prior of spatial aggregation and spectral contribution, the segmentation-based classification exhibits its superiority over a pixel-based classification. Finally a GIS-based post procedure is hired to eliminate some unsuitable open space components in both spatial and numerical constraints on the one hand, and separate open space some fabrics from fused remote sensing classes by defining their Shape Index on the other hand. The case study of Beer Sheva based on ASTER data proves this method is a feasible way for open space extraction.     

基于GWR的丁家山铅锌矿控矿因素影响研究

在成矿预测领域,探索各控矿因素对成矿的影响规律,有助于提高成矿预测模型的精准度。隐伏矿体矿产分布具有真三维特性,利用经典统计模型和计量方法进行成矿预测存在可靠性低的问题。三维地理加权回归将真三维空间的位置信息加入普通线性回归模型,更有利于探究矿产分布及其控矿因素之间的内在联系。以福建丁家山铅锌矿Pb品位及其控矿因素数据为例,在排除各控矿因素变量之间存在的多重共线性问题以及证实福建丁家山铅锌矿Pb品位数据具有显著的空间自相关的基础上,对该组数据分别进行了普通线性回归分析和三维地理加权回归分析。结果表明,采用地理加权回归模型比采用普通线性回归模型具有更高的显著性,验证了各控矿因素对成矿的影响具有空间非平稳性。同时,通过采用自适应带宽对地理加权回归方法不同权函数运算结果的对比,证明Tricube权函数更能体现各控矿因素对成矿的影响随距离衰减的规律。从不同核函数的地理加权回归模型在三维空间的作用效应来看,各控矿因素的三维空间非平稳性显著,表明三维空间的地理加权回归模型在地下矿体建模与预测等方面还有很大的发展空间。     

2009年若干典型低轨空间区域空间碎片分布仿真

空间碎片在太空中的累积越来越多,它们主要聚集在离地球表面2000km高度以下空间区域内.空间碎片引起的空间"污染"越来越威胁到在轨工作飞行器的安全.这里主要对600km、700km和800km轨道高度,倾角分别为30°、60°和98°的低轨道空间区域的空间碎片分布进行了仿真计算.可以为在轨飞行器安全运行及未来飞行器在空间布局决策提供一定参考.     

The impact of planning on pedestrian movement: contrasting pedestrian movement models in pre-modern and modern neighborhoods in Israel

Most pedestrian movement volume models were constructed for urban areas that developed on the basis of pre-modern planning. In this paper, we confront neighborhoods that were built upon modern planning doctrines, combining the functional hierarchy of streets with the neighborhood unit concept, with neighborhoods that developed from pre-modem non-hierarchical street-based planning. We use space syntax analysis to investigate how their street network’s structural attributes interact with pedestrian movement distribution. The investigation was conducted in 14 neighborhoods from 4 cities in Israel by examining the correlation of observed pedestrian volume with models using different axial- and segment-based topological, angular, and metric syntactic attributes across different radii (scales). The results indicate that the street network and the distribution of pedestrian movement interact differently in the two neighborhood types. In pre-modern neighborhoods: (i) there is significantly more walking; (ii) the street network’s syntactic attributes tend to be much more consistent in their correlation with pedestrian volume across all scales; (iii) the correlation of pedestrian volume with these attributes and with commerce is relatively high; and (iv) pedestrian movement distribution is more predictable. We relate these differences to the absence of a self-organized circular causality between street network structure, commerce, and movement in modern planned neighborhoods.     

GIS conceptual data model

In order to set up a conceptual data model that reflects the real world as accurately as possible, this paper firstly reviews and analyzes the disadvantages of previous conceptual data models used by traditional GIS in simulating geographic space, gives a new explanation to geographic space and analyzes its various essential characteristics. Finally, this paper proposes several detailed key points for designing a new type of GIS data model and gives a simple holistic GIS data model.