延庆盆地北缘断裂带蚕房营段晚更新世晚期断层作用

通过１个探槽记录、３个地质学剖面、７个晚更新世沉积物表面断层崖形态学剖面和１５个放射性测年数据，论述了延庆盆地北缘断裂带蚕房营段的晚更新世晚期断层作用。这些资料显示出该时期内的两次断层作用事件：最近的一次发生在９８７０±１３０～１１８００±１１００ａＢ．Ｐ．之间，最早不超过１３２００±ｌ１００ａＢ．Ｐ．；较早一次的发生时间为１９８５０±１５５０ａＢ．Ｐ．。一次事件的位移量３．３４～３．６４ｍ，两次事件之间的重复间隔９９８０ａ。大约自２１０５０±１６００ａＢ．Ｐ．以来的垂直位移速度计算为０．３１～０．３４ｍｍ／ａ。蚕房营段的晚更新世晚期的断层作用，以较大的表面位移量和较长的重复间隔为特征。全新世没有类似的断层作用事件     

龙门山断裂带茂汶—汶川段的长期强震潜势

本文针对自然生态系统和人工生态系统，分别讨论了公路在选线、施工和运营期对生态的影响，以及通过生态工程达到生态恢复和优化的设想，并首次阐述了“路界生态系统”的概念和内容。     

郯(城)—庐(江)断裂带赤山段晚白垩世晚期以来构造应力场

本文依据对晚白垩世晚期和晚更新世地层中发育的共轭剪节理分析,结合野外地质调查、断层泥显微构造分析以及地应力测量和区域构造应力场演化特征分析,反演了郯一庐断裂带赤山段及近侧地区晚白垩世晚期以来的构造应力场,得到:Ⅰ期,σ_1为近南北向,作用时间自古新世后至晚更新世之前;Ⅱ期,σ_2为北东东—南西西至近东西向,作用时间始于晚更新世后,其影响可能延续至今。两期应力均以水平方式作用为主,且分别与宏、微观构造形迹相对应。     

基于特征的最小二乘匹配理论精度

本文对SODAMS中采用的新的特征提取方法和基于特征的最小二乘匹配的精度以及特征的信噪比、特征检测的若干阈值、特征的倾斜度与精度的关系、特征线方向与精度的关系等问题,进行了分析与讨论。分析表明,在比较理想的情况下,基于特征的最小二乘匹配的精度可达1μm以下。     

北秦岭西段早古生代埃达克岩地球化学特征及岩石成因

唐藏石英闪长岩体出露于北秦岭造山带西段,侵入于丹凤群火山沉积岩系之中,主要矿物组成为斜长石、角闪石、石英、钾长石、黑云母等,形成时代为454Ma。该岩体SiO2= 62.02％～64.26％;Al2O3=16.55%～17.45%,MgO=1.71%～2.09%, Sr = (1069～1296)×10-6（>400 ×10-6）,Y = (11.6～13.81)×10-6 （<18×10-6）,Yb = (0.96～1.14)×10-6（<1.9 ×10-6）,Sr/Y=80.98～108.19（>40）,稀土总量（∑REE=217.88×10-6～355.07×10-6）较高,LREE强烈富集,重稀土亏损,Eu负异常不明显（LREE/HREE=17.72~25.82;LaN/ YbN=44.56～53.85;δEu＝0.82～1.0）,显示出典型埃达克岩的岩石地球化学特点。在以原始地幔标准化的微量元素分布图中,大离子亲石元素（LILE）K、Th、Rb、Ba、Sr等富集,高场强元素(HFSE)Ta、Nb、Y、Yb等较相邻元素相对亏损,微量元素曲线分布形式及稀土元素配分模式与典型地区埃达克岩分布形式一致。研究表明,该岩体Na2O＝4.99%～6.91%, Na2O-2＞K2O,Mg#＝0.59～0.63, A/CNK=0.82～1.01,σ=4.24～2.24,为富钠偏铝质高镁埃达克岩。唐藏埃达克岩体岩浆源于早古生代秦岭商丹洋向北俯冲消减洋壳板片的部分熔融,岩浆在上升过程中与地幔楔发生反应。北秦岭早古生代埃达克岩的确定为探讨秦岭早古生代构造演化提供了新的证据。     

融合直角点和直角边特征的高分辨率遥感影像居民点提取方法

提出了一种融合直角点和直角边两种特征的高分辨率遥感影像居民点提取方法:首先,分别检测高分辨率遥感影像的角点和直线段,通过两种特征交叉验证确定直角点和直角边,并对二者进行栅格化;然后,基于局部直角点和直角边点的密度和距离特征生成居民点指数图像;最后,通过指数图像二值化、栅格转矢量、剔除小图斑等操作确定居民点多边形。使用3景影像进行了试验。试验结果表明,本文方法提高了居民点提取精度,其正确率、完整率、质量等3个指标的平均值比已有方法的相关值分别高6.76%、10.12%、12.14%。     

东昆仑东段益克郭勒侵入岩LA-ICP-MS锆石U-Pb定年及其地质意义

东昆仑东段益克郭勒侵入体主要由闪长岩、石英碱长正长岩、英云闪长斑岩及花岗闪长岩组成.锆石LA-ICP-MS U-Pb定年结果显示,闪长岩、石英碱长正长岩和英云闪长斑岩的年龄分别为(223.4±1.1)Ma、(222.9±1.3)Ma和(230.9±1.1)Ma,表明益克郭勒侵入体形成于中三叠世.益克郭勒中三叠世侵入岩属...     

Relationship of uncertainty between polygon segment and line segment for spatial data in GIS

The mathematic theory for uncertainty model of line segment are summed up to achieve a general conception, and the line error band model of ?σ is a basic uncertainty model that can depict the line accuracy and quality efficiently while the model of ?m and error entropy can be regarded as the supplement of it. The error band model will reflect and describe the influence of line uncertainty on polygon uncertainty. Therefore, the statistical characteristic of the line error is studied deeply by analyzing the probability that the line error falls into a certain range. Moreover, the theory accordance is achieved in the selecting the error buffer for line feature and the error indicator. The relationship of the accuracy of area for a polygon with the error loop for a polygon boundary is deduced and computed.     

A new approach to simulate positional error of line segment in GIS

To determine the distribution of positional error of a line segment, Monte Carlo approach is applied to simulate the probability density function of a line segment with the assumption that the error of endpoints in a line segment follows a two-dimensional normal distribution. For such purpose, a stochastic generator used for uncertain endpoints with the two-dimensional normal distribution is presented. This forms the basis of the generation of random line segment for the simulation of the error model of a whole line segment. The error models cover the cases where two endpoints are either independent or dependent to each other, also including a special case that the distance between two random endpoints in a line segment is close enough.     

General entropy model of line segments uncertainty in GIS

Spatial data uncertainty can directly affect the quality of digital products and GIS-based decision making. On the basis of the characteristics of randomicity of positional data and fuzziness of attribute data, taking entropy as a measure, the stochastic entropy model of positional data uncertainty and fuzzy entropy model of attribute data uncertainty are proposed. As both randomicity and fuzziness usually simultaneously exist in linear segments, their omnibus effects are also investigated and quantified. A novel uncertainty measure, general entropy, is presented. The general entropy can be used as a uniform measure to quantify the total uncertainty caused by stochastic uncertainty and fuzzy uncertainty in GIS.