Microfocus X-ray computed tomography analysis of corroded glass objects

Microfocus X-ray computed tomography (µCT) is a useful tool for non-destructive analysis of corroded archaeological glass objects and for monitoring restoration and conservation processes for these materials. This was demonstrated by µCT analysis of artificially corroded laboratory-produced glasses and corroded archaeological glasses retrieved from soil environments. Corrosion layers with a thickness of 20 µm or more can be detected as areas with lower X-ray attenuation values than the non-corroded glass. Features that are revealed by µCT analyses include the degree and patterns of corrosion and the presence of various internal structures in the corrosion layers. The study of restored corroded glasses demonstrates that mechanical and laser cleaning can be monitored efficiently. The study of consolidation practices, using test objects, requires the use of additives to increase X-ray attenuation values of the organic compounds that are used.     

地质灾害野外调查数据采集系统数据模型研究

文章从需求分析着手,利用3S技术、结合现代化的掌上电脑,从系统构成、野外数据采集模型、实体模型等方面对系统的构建进行了探讨研究.最后结合设计,利用国产的嵌入式GIS软件MAPGIS,实现了集野外数据的组织、采集背景文件的发布、采集数据收集一体化工作流程的地质灾害野外数据数字采集系统.     

数字式全景钻孔摄像在某洞室勘察中的应用

在地下洞室的勘察中。数字式全景钻孔摄像通过对钻孔孔壁的拍摄处理．给出了全孔的孔壁展开图和三维虚拟岩芯图，并对深层岩脉、节理．裂隙的产状和宽度进行量化的统计，为地下洞室的布置和岩石质量评价提供了翔实可靠的数据，通过工程实例阐述了数字式全景钻孔摄像技术在花岗岩地区地下洞室勘察中的应用。     

Experimental investigation of microstructural changes in soils eroded by suffusion using X-ray tomography

Internal erosion is a complex phenomenon which represents one of the main risks to the safety of earthen hydraulic structures such as embankment dams, dikes or levees. Its occurrence may cause instability and failure of these structures with consequences that can be dramatic. The specific mode of erosion by suffusion is the one characterized by seepage flow-induced erosion, and the subsequent migration of the finest soil particles through the surrounding soil matrix mostly constituted of large grains. Such a phenomenon can lead to a modification of the initial microstructure and, hence, to a change in the physical, hydraulic and mechanical properties of the soil. A direct comparison of the mechanical behaviour of soil before and after erosion is often used to investigate the impact of internal erosion on soil strength (shear strength at peak and critical state) using triaxial tests. However, the obtained results are somehow contradictory, as for instance in Chang’s study (Chang and Zhang in Geotech Test J 34(6):579–589, 2011), where it is concluded that the drained strength of eroded soil decreases compared to non-eroded soil, while both Xiao and Shwiyhat (Geotech Test J 35(6):890–900, 2012) and Ke and Takahashi (Geotech Test J 37(2):347–364, 2014) have come to the opposite conclusion. A plausible explanation of these contradictions might be attributed to the rather heterogeneous nature of the suffusion process and to the way the coarse and fine grains are rearranged afterwards leading to a heterogeneous soil structure, a point that, for now, is not taken into account, nor even mentioned, in the existing analyses. In the present study, X-ray computed tomography (X-ray CT) is used to follow the microstructure evolution of a granular soil during a suffusion test, and, therefore, to capture the induced microstructural changes. The images obtained from X-ray CT reveal indeed that fine particles erosion is obviously not homogeneous, highlighting the existence of preferential flow paths that lead to a heterogeneous sample in terms of fine particles, void ratio and inter-granular void ratio distribution.

     

基于3S技术的地质灾害野外调查数字采集系统的研究

传统上,区域野外地质灾害调查主要是利用罗盘、地质锤、放大镜等工具进行等在野外完成,日后专业人员获取这些灾害点的相关原始数据需要从资料室的资料柜里进行查找并整理后进行统计分析,这种工作模式不利于数据共享与管理,也不适应"数字国土"工程的建设节奏,因此,基于3S技术建立一套集野外数字采集、成图、分析以及数据输出一体化的地质灾害野外调查数字采集系统是解决上述问题的关键所在。本文从需求分析着手,从系统构成、野外数据采集模型、实体模型、系统功能等方面对系统的构建进行探讨研究,最后结合本文的设计,利用国产的嵌入式GIS软件MAPGIS,实现了集野外数据的组织、采集背景文件的发布、采集数据收集一体化工作流程的地质灾害野外数据数字采集系统。     

The use of X-ray computer tomography to investigate particulate interactions within opencast coal mine backfills

Restoration of opencast coal sites frequently involves the controlled compaction of heterogeneous arisings, and accurate prediction of the settlements associated with such backfill is difficult. Attention has previously focussed on improving the specifications used to control backfilling as a way of both reducing the magnitude of the settlements and improving their predictability. However, there still exists a large degree of uncertainty about the fundamental particulate interactions that occur within a fill. The range of mechanisms previously considered to be influential on creep behaviour is described.

A current research programme is investigating the use of X-ray computer tomography (CT) as a means of nondestructively observing particle interactions during settlement, in conjunction with both long-term creep tests and short-term compressibility tests. The principles of this radiographic technique, which is relatively new to geotechnical engineering, are described, and findings are presented that illustrate the potential of the method.

Interim findings indicate that large particles are distributed on an apparently random basis within a fill, and the nonuniform distribution of voids is clearly demonstrated. Moreover, the results presented conflict to some degree with the general consensus of opinion that particle crushing is a major mechanism in the settlement process. Rather, local collapse into small voids left by compaction, and relative sliding and rotation of particles, seem to be the dominant factors for a range of compaction efforts. Particle splitting is discernible on some sections, but this mechanism appears to be less significant than others. Research is continuing into the time dependency of the observed mechanisms, the effects of moisture content changes and the effects of heterogeneous initial particle strengths.     

Reality of the relation between geological objects and mathematical models

Mathematical models and their targets are considered. The results provide an explanation why the shape of the density distribution function is dependent upon both size of the geological object and number of observations. These results have importance both for preparative and interpretative phases of prospecting.     

浅谈城市地质调查与地质灾害治理在城市建设中的作用

由于城市规模的进一步扩大,基本建设的项目不断增加,在建设过程中发生的地质灾害也越来越多。从地质因素在城市建设中的表征入手,论述了开展城市地质灾害调查与治理的必要性及可操作性。依据江苏各大城市的地质构造特点及存在的地质灾害隐患,提出了对城市地质灾害调查与治理的设想。     

新疆白杨河铀矿床钻孔岩芯蚀变分带特征及地质意义

钻孔岩芯高光谱技术是获取岩芯地学信息与研究的新方向。新疆白杨河铀矿床钻孔岩芯蚀变发育,对其开展蚀变研究有助于对白杨河矿床深部铀矿勘探提出更好的找矿认识。本次研究利用Field Spec4可见光-短波红外地面非成像光谱仪对新疆白杨河铀矿床8个钻孔进行光谱测试与分析,研究发现钻孔岩芯热液蚀变矿物组合垂向上具有明显的"上低下高中过渡"的三分带特征:即上部为低铝绢云母+少量赤铁矿与少量褐铁矿+少量蒙脱石,中部为中铝绢云母+低铝绢云母+少量蒙脱石+少量碳酸盐、赤铁矿与褐铁矿,下部为高铝绢云母+绿泥石+碳酸盐;绢云母Al-OH吸收峰位置变化规律反映出矿床的热液活动具有深部相对高温、高压、偏酸性,浅部相对低温、低压、偏碱性的特征。蚀变三分带特征以及热液活动特征表明白杨河铀矿床具有明显的热液成矿背景,同时,铀矿化总体处于3分带特征中的中部以中铝绢云母为主的蚀变带与下部以高铝绢云母为主的蚀变带之间的过渡带中,该过渡带是铀成矿的有利部位,同时也是可能的热液/矿化中心;过渡带中发育赤铁矿,中铝绢云母和高铝绢云母,此3种蚀变矿物可能与铀成矿关系密切。这些可以为白杨河铀矿床深部铀矿勘探提供借鉴与参考。     

X-ray and electron-optical investigation of synthetic high-temperature plagioclases

High-temperature plagioclases NaAlSi₃O₈(Ab)-CaAl₂Si₂O₈(An) have been prepared by dry devitrification of glasses. X-ray powder photographs were taken to follow the time-temperature dependence of indicators of structural state and to determine the lattice parameters of the plagioclases as well as their K-exchanged equivalents. Transmission electron microscopy (TEM) has been used to study the anorthite-type antiphase domain textures. The results are as follows:

1. TEM and X-ray powder data suggest to subdivide the high-temperature plagioclase series into three structural regions: (a) An0 to An30–40: monalbite/analbite to high albite-type structures, (b) An60–70 to An100: anorthite-type structures, (c) An30–40 to An60–70: transitional structures assumed to represent the early stages in the development of the structural complexities found in chemically intermediate low temperature plagioclases.
2. b-Antiphase domains typical for the anorthite-type structure could be imaged in samples ranging between An100 and An67.5, whereas c-antiphase domains have only been found in An90 and An100. The b-domains developed during isothermal crystallization, rather than cooling. The transition from the anorthite-type structure (S.G.I \(\bar 1\) ) to an intermediate C \(\bar 1\) -type structure at An60–70 appears to be a gradual one.
3. The relative contribution of various structural and chemical influences on the cell edges and angles is discussed in detail. It is shown that the nonlinear variation of γ with An content is due to incomplete Al,Si disorder in the high series.

     

新形势下地质调查工作的责任与任务

１地质调查工作面临的新形势和新方向世纪之交的２０００年，是不平凡的一年，特别是对国土资源工作来说尤其如此。中共中央十五届五中全会通过了制订国民经济与社会发展第十个五年计划的建议，把粮食、油气和水资源列为影响国民经济持续发展、国家经济安全的三大战略问题，给地质调查工作提出了前所未有的国家需求。地球科学被列为与基因组学、信息科学、纳米科学、生态科学、空间科学等六大国家重点发展学科之一，对地球的探测和研究被放在极重要的位置。朱镕基总理在九届人大四次会议上的讲话把高度重视和认真解决人口、资源和生态环境问…     

Effect of the initial density and angular-velocity profiles of pre-stellar cores on the properties of young stellar objects

The physical properties of young stellar objects are studied as functions of the initial spatial distributions of the gas surface density Σ and angular velocity Ω in pre-stellar cores using numerical hydrodynamic simulations. Two limiting cases are considered: spatially homogeneous cores with Σ = const and Ω = const and centrally concentrated cores with radius-dependent densities Σ ∝ r ⁻¹ and Ω ∝ r ⁻¹. The degree of gravitational instability and protostellar disk fragmentation is mostly determined by the initial core mass and the ratio of the rotational to the gravitational energy, and depends only weakly on the initial spatial configuration of pre-stellar cores, except for the earliest stages of evolution, when models with spatially homogeneous cores can be more gravitationally unstable. The accretion of disk matter onto a protostar also depends weakly on the initial distributions of Σ and Ω, with matter from the collapsing core falling onto the disk at a rate that is slightly higher in models with spatially homogeneous cores. An appreciable dependence of the disk mass, disk radius, and the disk-to-protostar mass ratio on the initial density and angular velocity profiles of the parent core is found only for class 0 young objects; this relationship is not systematic in the later I and II stages of stellar evolution. The mass of the central protostar depends weakly on the initial core configuration in all three evolutionary stages.     

基于数字地质调查系统的矿产远景调查数据库建设——内蒙古达来庙矿产远景调查项目数据库的建设和体会

2007年5月由中国地质调查局主管部门建议．选定内蒙古达来庙地区的矿产远景调查项目作为矿产远景调查数据库系统应用的试点项目,全面开展了矿调数据库的建设。根据矿调工作的特点．项目利用数字地质调查系统完成了①地质填图野外数据PRB库;②实际材料图数据库;③地质矿产图空间数据库;④地球化学数据库;⑤地球物理数据库;⑥遥感数据库;⑦综合成果数据库和⑧大比例尺综合图数据库的建设,从而实现了将矿调工作原始资料、成果资料集于数字地质调查系统同一平台下的全部数字化。     

基于数字地球平台的地质钻孔三维模拟与可视化

研究了地质钻孔信息的管理和可视化技术,提出了一种在数字地球平台中进行城市钻孔信息模拟和可视化的方法。该方法基于一个统一的钻孔数据库标准,首先将钻探点位信息和地层分层信息组织成具有不同细节层次的钻探点位模型、钻孔分层散点模型和钻孔管段模型,然后构建基于细节层次模型的海量钻孔信息多尺度表达机制,最后将这些模型加载到数字地球平台中进行可视化及查询、分析。在上海市的应用实例显示,该方法实现过程简单、自动性高,生成的模型易于在国际互联网上进行分发、集成与共享。该方法的应用将有助于地质工作者向其他科技人员以及社会公众展示、分发自己拥有的钻孔信息,为以钻孔数据为代表的城市地质信息的社会化服务奠定基础。     

绞车下降速度、深度数字显示仪在地质钻探中的应用

为了方便地质钻探,设计了绞车下降速度、深度数字显示仪,经机台上使用,操作简单方便,效果良好,值得推广。     

中华人民共和国1∶50万数字地质图和空间元数据

本文简要介绍了我国首次利用GIS计算机技术,编制并建成的基础性和公益性<中华人民共和国1∶50万数字地质图空间数据库>及其"元数据库”.     

大数据环境下数字填图数据集成服务技术

应用数字填图技术形成了大量地质填图图幅数据,这些数据空间结构化和非结构化特征并存,如何在网络环境下提供高效的数据服务是急需解决的一个难题。大数据技术的发展为数字填图、数据集成服务提供了一种新的途径。通过对数字填图数据特征的分析,在研究地质调查信息网格大数据处理框架的基础上,提出了结构化和非结构化数据相结合的有序化组织管理、发布与服务方法,并对关键技术进行了研究与试验,取得了良好的效果。     

大数据环境下数字填图数据集成服务技术

应用数字填图技术形成了大量地质填图图幅数据,这些数据空间结构化和非结构化特征并存,如何在网络环境下提供高效的数据服务是急需解决的一个难题。大数据技术的发展为数字填图、数据集成服务提供了一种新的途径。通过对数字填图数据特征的分析,在研究地质调查信息网格大数据处理框架的基础上,提出了结构化和非结构化数据相结合的有序化组织管理、发布与服务方法,并对关键技术进行了研究与试验,取得了良好的效果。     

西安城市区工程地质环境与岩土工程勘察特点探讨

对西安城市区工程地质环境进行了分区 ,论述了各区的工程地质环境特征 ,分析了各区岩土工程勘察的特点 ,评价了各区作为拟建工程场地与地基的条件 ,提出了利用、整治和改造岩土的可能方案与措施