一种频域高分辨率遥感图像线状特征检测方法

高分辨遥感图像中线状特征等的自动识别与提取是进行遥感图像分析与理解等高层次图像工程的前提和基础,但由于高分辨率遥感图像中细节信息异常丰富,这给特征的提取带来很大干扰。本文引入了一种基于方向和频率特征的遥感图像频域线状特征检测方法,该方法首先通过傅氏变换将图像变换到频率域,在详细分析线状特征和谱线的关系,线状特征和图像频率之间关系的基础上,基于分析得到的方向和频率的参数构造Gabor滤波器进行图像线状特征的提取。并以Quick bird高分辨率遥感图像进行相关提取实验,实验结果表明该方法较好地提取了图像的线状特征,为基于具体频谱分析的高分辨率遥感图像特征的精确提取提供了新思路和方法上的借鉴。     

建库与制图数据一体化生产与管理技术的研究与实践

本文通过对目前建库与制图数据生产与管理的现状,以及这两种数据特点的分析,阐明了建库与制图数据生产与管理一体化的真正含义和一体化空间数据模型的内容,通过在建库与制图数据一体化软件平台--Map-Store基础测绘版上的实践,总结了建库与制图数据一体化工艺方法和质量控制,在建库与制图数据一体化数据管理的基础上实现两种数据快...     

Prestack Kirchhoff time migration of 3D coal seismic data from mining zones

Conventional seismic data processing methods based on post‐stack time migration have been playing an important role in coal exploration for decades. However, post‐stack time migration processing often results in low‐quality images in complex geological environments. In order to obtain high‐quality images, we present a strategy that applies the Kirchhoff prestack time migration (PSTM) method to coal seismic data. In this paper, we describe the implementation of Kirchhoff PSTM to a 3D coal seam. Meanwhile we derive the workflow of 3D Kirchhoff PSTM processing based on coal seismic data. The processing sequence of 3D Kirchhoff PSTM includes two major steps: 1) the estimation of the 3D root‐mean‐square (RMS) velocity field; 2) Kirchhoff prestack time migration processing. During the construction of a 3D velocity model, dip moveout velocity is served as an initial migration velocity field. We combine 3D Kirchhoff PSTM with the continuous adjustment of a 3D RMS velocity field by the criteria of flattened common reflection point gathers. In comparison with post‐stack time migration, the application of 3D Kirchhoff PSTM to coal seismic data produces better images of the coal seam reflections.     

数码调绘系统在1∶10000数字化图生产中的应用

针对野外测量生产数字化的薄弱环节研发的数码调绘系统,提高了野外调绘的工作效率,解决了新增地物标绘的精度问题,为数字化图生产与建库的前端数据采集提供了新方法。主要介绍数码调绘系统在基础测绘1∶10000数字线划图生产中的应用,通过对数码调绘系统定位精度的检测,进一步阐述其优势及实际应用中应注意的问题。     

Multielemental contents of foodstuffs from the Wanshan (China) mercury mining area and the potential health risks

Potentially harmful element contamination from mining and smelting raises concerns due to possible health risks. For most people, diet is the main route of exposure to potentially harmful elements, so determination of the concentrations of these elements in foodstuffs and assessment of their possible risk for humans via dietary intake is very important. This study was designed to investigate the concentrations of different elements, including Hg, Pb, Cd, Mn and Se in foodstuffs and to estimate the potential health risk of these elements via consumption of polluted foodstuffs in the Wanshan Hg mine area, Guizhou province, SW China. The multielemental concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The target hazard quotient (THQ) and hazard index (HI) were calculated to evaluate the potential health risk from individual and combined potentially harmful elements due to dietary intake. The average contents of Hg, Pb, Cd, Mn and Se in the most frequently consumed foodstuffs were: 31, 248, 121, 1035 and 32 μg/kg respectively. Among them, Cd and Hg were the most important contributors to potentially harmful elements contamination in Wanshan. Eight of 10 kinds of vegetables were contaminated to various levels by different elements but the samples of rice, pork, radish and potato were below the stipulated limits for toxic elements. In this study, the average dietary intakes of Hg, Pb, Cd, Mn, Se by an adult man of 60 kg living in Wanshan were: 27, 167, 86, 1061, 42 μg/day, respectively. The HIs for multielement dietary intake was 3.11, with the relative contributions of Hg, Pb, Cd, Mn and Se being 22.3%, 24.3%, 45.0%, 3.9% and 4.4%, respectively, which indicated that consumption of food poses a potential health risk. Vegetables were found to be the main source of potentially harmful element dietary intake.     

甘肃武都万象洞方解石现代沉积控制因素分析

对洞穴次生碳酸盐沉积机理的认识是解释洞穴石笋气候环境指示意义的关键.近两个水文年的洞穴现代过程监测结果显示,万象洞内温湿度全年基本保持恒定;洞穴滴水的pH值夏季偏低、冬季偏高,呈现出一定的季节变化特征,电导率和HCO3-浓度及主要阴阳离子含量年内变化不显著;洞内CO2分压夏季偏高,冬季降低接近于当地大气的CO2分压水平.对不同滴水点的对比研究表明,滴水中Ca2+达到一定浓度是方解石沉积的必要条件.此外,万象洞夏季CO2分压的升高对方解石形成产生明显的抑制作用.万象洞石笋沉积的主要受控于滴水饱和度以及洞穴CO2分压.     

富县地区延长组储层特征及其非均质性

富县地区延长组主要发育三角洲和湖泊沉积体系,其中分流河道和水下分流河道骨架砂体呈北东-南西向条带状展布,纵向上连续性好,是主要储集体。岩性主要为灰色-灰绿色细-中粒岩屑长石砂岩和长石砂岩,填隙物主要是胶结物,以方解石、绿泥石膜为主。主要受沉积和成岩作用两个因素控制,储层物性较差,纵向上和横向上非均质性均较强。层内非均质性主要影响因素为垂向上粒度分布的韵律性、层理构造、层内夹层和层内裂缝等,层内渗透率非均质参数表现为中等-强的非均质性;分层系数和砂岩密度长8、长6、长3和长2油层组较大,长7和长4+5油层组较小;层间渗透率非均质参数长8、长6及长3较大,为强非均质性,长7和长2较小,非均质性相对较弱,为中等非均质性。     

A study on the interaction between ferric ion and silicic acid in hydrosphere: Si-containing ferruginous deposits formed in neutral hot spring waters

Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), infrared (IR) spectroscopy, powder X-ray diffraction (XRD), and 57Fe Mssbauer spectroscopy. The Si/Fe atomic ratios of the deposits ranged from 0.25 to 0.45, and were smaller than those of hisingerite (12), but apparently close to those of siliceous ferrihydrite (0.250.5). Si was confirmed to be present as monomeric or oligomeric silicate from the Si-O stretching vibration frequencies on the IR spectra. Judging from the results of DTA, which minerals starting to produce after heating, and a relationship between Si-O stretching vibration frequency and Si/Fe atomic ratio proposed by Henmi et al. (1981), all the deposits in this study were concluded to be mixtures of various siliceous ferri-hydrites with low and high Si/Fe atomic ratios. Moreover, by comparing the chemical properties of hot spring waters, the formation conditions of siliceous ferrihydrite were also discussed.     

Polarization Observation Experiments for Radio Flares of Stars at the 6 cm Band

We have performed radio polarization observation experiments of the stars V772 Her and β Per with the Urumqi 25 m radio telescope at the 6 cm waveband, and obtained light curves of the stars after data processing and calibration. A radio ?are from the star V772 Her was detected on 2011 April 13. The degree of linear polarization of this ?are is about 30%, and the polarization angle is about 4°. We have detected also the slowly-varying component of the radio radiation from β Per, as well as a short ?are superposed on it, which has a very weak linear polarization.     

Moon night sky brightness simulation for the Xinglong stationSong Yao

Using a sky brightness monitor at the Xinglong station of National Astronomical Observatories,Chinese Academy of Sciences,we collected data from22 dark clear nights and 90 moon nights.We first measured the sky brightness variation with time for dark nights and found a clear correlation between sky brightness and human activity.Then with a modified sky brightness model of moon nights and data from these nights,we derived the typical value for several important parameters in the model.With these results,we calculated the sky brightness distribution under a given moon condition for the Xinglong station.Furthermore,we simulated the sky brightness distribution of a moon night for a telescope with a 5 field of view（such as LAMOST）.These simulations will be helpful for determining the limiting magnitude and exposure time,as well as planning the survey for LAMOST during moon nights.