银矿自然重砂矿物组合规律及其找矿意义

根据20世纪60年代全国范围内展开的自然重砂测量工作所累积的自然重砂数据资料,统计了全国各省72个典型银矿床的自然重砂情况,通过计算和分析各自然重砂矿物在所对应的类型的矿床中的报出频率,得出火山沉积型、沉积型、变质型、侵入岩型4种类型的银矿所对应的自然重砂矿物组合。展现这4种类型矿床的重砂矿物组合的相似之处及不同之处。按照这种方式建立的不同矿床类型的自然重砂矿物组合,对于建立自然重砂找矿模型具有重要的意义。     

A method for mineral prospectivity mapping integrating C4.5 decision tree,weights-of-evidence and m-branch smoothing techniques: a case study in the eastern Kunlun Mountains,China

In this study, a novel method that integrates C4.5 decision tree, weights-of-evidence and m-branch smoothing techniques was proposed for mineral prospectivity mapping. First, a weights-of-evidence model was used to rank the importance of each evidential map and determine the optimal buffer distance. Second, a classification technique that uses a C4.5 decision tree in data mining was used to construct a decision tree classifier for the grid dataset. Finally, an m-branch smoothing technique was used as a predictor, which transformed the decision tree into a probability evaluation tree. The method makes no conditional independence assumption and can be applied for class imbalanced datasets like those collected during mineral exploration for prospectivity mapping of an area. The traits of comprehensibility, accuracy and efficiency were derived from the C4.5 decision tree. In addition, a case study for iron prospectivity mapping was performed in the eastern Kunlun Mountains, China. Sixty-two Skarn iron deposits and eight evidential maps related to iron mineralization were studied. On the final map, areas of low, moderate and high potential for iron deposit occurrence covered areas of 71,491, 14,298, and 9,532 km², respectively. For the goodness-of-fit test, 91.94 % of the total 62 iron deposits were within a high-potential area, 8.06 % were within a moderate-potential area and 0 % were within a low-potential area. For ten-fold cross-validation, 82.26 % were within a high-potential area, 14.52 % were within a moderate-potential area and 3.22 % were within a low-potential area. To evaluate the predictive accuracy, Receiver Operating Characteristic (ROC) curves and Area Under ROC Curve (AUC) were employed. The accuracy of the goodness-of-fit test reached 97.07 %, and the accuracy of the ten-fold cross-validation was 95.10 %. The majority of the iron deposits were within high-potential and moderate-potential areas, which covered a small proportion of the study area.     

仿示波器显示在长周期MT测深仪中的应用

MTU-5、V8、LEMI-417等大地电磁测深仪器的人机交互方式均基于文字,用户仅凭文字难以发现采集中的问题。由于示波器能把人眼无法直接捕捉到的电信号的时变规律以可见的图像形式显示出来,故将该技术应用于长周期大地电磁测深仪CLP中,使仪器的人机交互方式基于图形用户界面(GUI)。本系统的GUI选用Visual C++6.0作为开发工具,在规划了显示区域,建立了设备环境类CDC以及CPen、CBitmap等绘图工具类的对象后,设计了仿示波器界面,在示波器界面中,用MoveTo与LineTo函数实现了对采集数据的实时动态显示。此外,使显示窗口自适应显示器分辨率属性、信号最大化显示、显示背景设置为灰白色,以方便操作。经野外试验,该显示技术有助于用户对采集的数据进行分析,为下一步工作提供依据。     

白山市三道阳岔铁矿床磁铁矿工艺矿物学研究

磁铁矿工艺学研究主要为白山磁铁矿在后期详查,开采,选矿方面,提供科学依据,对其进行了工艺学研究,研究结果表明:矿石中可供回收的主要金属矿物为磁铁矿,其他均达不到综合利用指标。     

区域土地利用影响地表CO2浓度异质性特征的动力学机制

本文综合应用高斯方程和拉姆齐模型,针对京津冀地区2000年以来10 km×10 km栅格尺度的地表CO₂浓度开展研究,分析了区域土地利用影响地表CO₂浓度异质性特征的动力学机制。研究发现：① 地表CO₂浓度与土地利用类型密切相关。2000—2018年京津冀地区CO₂浓度的高值区主要集中于经济较发达的快速城镇化地区;② 土地利用强度及土地利用效率上的时空分异为地表CO₂扩散提供了潜在的势能。京津冀地区地表CO₂排放及扩散存在明显的空间异质性,距离CO₂排放高值区越近,其相应的CO₂浓度越高并随时间推移及空间拓展呈逐步减小的态势;③ 京津冀地区在土地利用结构调整、格局优化及效率提升后,CO₂排放强度增幅明显减弱,其区域间的增幅差异也逐渐缩小。产业转型发展、土地利用格局优化、土地利用效率提高有效地抑制了京津冀地区地表CO₂排放强度的提升并促进了该区域的内涵式增长与高质量发展。     

细分移动互联网地理信息服务，构建宜居数字世界生活

移动互联网的发展在短时间内为地理信息带来了数亿用户,个人用户的增加,对地理信息提出了新的技术要求;地理信息界在努力,信息领域企业也在从信息基础设施角度向地理信息应用方向拓展,形成了目前信息技术企业与地理信息企业相向开发的局面;地理信息用户和行业的快速扩张,对行业管理提出了更高要求,需要许可认证、市场范围秩序维持等新的手段;地理信息有了与能力相适应的角色需要。以服务数字世界、打造虚拟社会中的宜居生活为目标,做好粘结剂,实现现实世界与数字世界的互动。     

基于Silverlight的区域变迁演示系统的设计

各民族、各国家的区域范围在不同的发展时期大小不一。本文提出了基于Silverlight的区域变迁演示系统设计,以江东六十四屯区域演变为例,基于Silverlight,Bing Maps,Sql Server,Visual Studio.NET等关键技术与软件平台,将历史、地理知识与测绘地理信息高度结合,设计出表现力丰富、交互能力强的区域变迁演示系统,实现让单一的历史地图以生动活泼的新面貌向世人展示等功能。     

A multi‐proxy sediment record of late Holocene and recent climate change from a lake near Ny‐Ålesund,Svalbard

Jiang, S., Liu, X., Sun, J., Yuan, L., Sun, L. & Wang, Y. 2011: A multi‐proxy sediment record of late Holocene and recent climate change from a lake near Ny‐Ålesund, Svalbard. Boreas, Vol. 40, pp. 468–480. 10.1111/j.1502‐3885.2010.00198.x. ISSN 0300‐9483 The Arctic constitutes a unique and important environment with a significant role in the dynamics and evolution of the earth system. Arctic lake sediments, which accumulate slowly over time, contain abundant information about the biological communities that lived within the water body, as well as in the surrounding catchment. In this study, we collected a sediment core from Ny‐Ålesund, Svalbard, performed multi‐proxy analyses on sediment pigments, mineral magnetic susceptibility, various sediment quality (i. e. organic matter content, CaCO₃ content, carbon and nitrogen isotope), and diatom composition, and reconstructed the history of ecosystem responses to environmental variations, especially regarding aquatic productivity and lake catchment surface processes. Ny‐Ålesund has undergone distinct ecological and climatic changes. During the Little Ice Age, the cold climate was unfavourable for the growth of lake algae, and therefore the lake primary productivity declined. After about AD 1890 and during the 20th century, the warming climate and reduced ice cover led to rapid lithological change and growth of lake algae, enhanced lake primary productivity, and increased input of nutrients derived from increased chemical weathering into the lake. The lake ecosystem on Ny‐Ålesund has had rapid responses to climatic and environmental changes in the Arctic.     

三维激光扫描技术在装配式架线施工中的应用

架线施工在送变电工程中是非常重要的一个环节,传统方式是采用弧垂法,但是效率很低,无法在跨越高速或高铁普及的条件下应用,需要应用装配式架线技术,目前经过验证的是通过全站仪配合棱镜测量的方式,但是也存在安全隐患。本文结合实际项目,探索研究三维激光扫描技术在装配式架线施工中的应用。     

页岩层系不同岩矿组合试样渗透率变化规律差异及其机理分析

页岩地层垂向岩矿组合变化大,页岩气开采需要对储层进行大规模人工水力压裂改造。笔者等基于样品的全岩X-射线衍射分析,通过对不同岩矿组合的3块页岩试样进行流—固耦合物理模拟实验,获得了3点认识,反映了不同岩矿成分的页岩在不同条件微裂缝与渗透率的变化特征,以及碳酸盐矿物含量高时的影响。这一实验对于研究页岩储层在压裂过程中的变化具有探索性,对于页岩气生产具有重要的参考意义。