2019年探矿工程十大新闻          下载免费PDF全文

本刊编辑部 《探矿工程》2020,47(1):1-4

  相似文献   

Calibration of a Par-Tec 200 laser back-scatter probe FOR in situ sizing of fluvial suspended sediment     

J. M. Phillips  D. E. Walling 《水文研究》1998,12(2):221-231

The in situ or effective particle size distribution of fluvial suspended sediment may differ considerably from that of the chemically dispersed mineral fraction owing to flocculation. Obtaining a meaningful measure of the effective particle size distribution ideally requires that measurements should be made in situ. A rigorous assessment of the associated degree of flocculation also requires that the same measurement technique is used subsequently to establish the absolute particle size composition of the suspended sediment by analysis of the chemically dispersed mineral fraction. While few in situ measurement devices currently exist, a Par-Tec 200 laser back-scatter probe has previously been shown to be capable of making both in situ and laboratory particle size measurements of fluvial sediment. The accuracy and precision of this device is assessed in this paper. While able to distinguish relative size differences with a high degree of precision, the Par-Tec 200 performed poorly in terms of accuracy when compared with measurements made using a laser diffraction device. A calibration algorithm has been devised for the Par-Tec 200 size data, using standard sediment samples sized by means of a laser diffraction device as the reference. Application of the calibration to Par-Tec 200 measurements of heterogeneous sediment samples significantly improved the representativeness of the particle size distribution, both in terms of overall form, and the median particle size. © 1998 John Wiley & Sons, Ltd.  相似文献   

砂岩型铀矿微区原位U-Pb同位素定年技术方法研究   总被引：2，自引：2，他引：0  

肖志斌  耿建珍  涂家润  张然  叶丽娟  毕君辉  周红英 《岩矿测试》2020,39(2):262-273

铀矿物定年一直是成矿年代学中的难点,随着微区原位U-Pb同位素定年技术的发展,可以直接针对矿石矿物(铀矿物)进行同位素定年;但是其中的砂岩型铀矿由于其存在状态复杂,在原位定年中剥蚀要求高,也缺乏合适的外部校正标准物质,所以定年准确度有待提高。本文研究了两种微区原位U-Pb同位素测年的方法,对砂岩型铀矿定年进行了尝试,试图解决铀矿测年中的无基体匹配问题并提高砂岩型铀矿定年水平。一是建立了一种激光剥蚀多接收电感耦合等离子体质谱仪联合电子探针进行微区原位U-Pb同位素测年的技术(LA-MC-ICP-MS&EMPA)。通过优化实验方法,对秦岭陈家庄花岗岩型铀矿进行了测试,获得与同位素稀释热电离质谱法(ID-TIMS)一致的年龄结果,证明了微区原位U-Pb同位素测年无基体匹配标准物质分析的可行性;并利用此法获得鄂尔多斯盆地红庆河和塔然高勒砂岩型铀矿的微区原位U-Pb同位素年龄信息。二是尝试了利用飞秒激光剥蚀多接收电感耦合等离子体质谱法(fsLA-MC-ICP-MS)对红庆河和宁夏宁东砂岩型铀矿样品进行微区原位U-Pb同位素定年,并获得了微区原位U-Pb同位素年龄,表明飞秒激光剥蚀技术在砂岩型铀矿定年中有很好的应用前景。本文提出,比较单一且年龄偏老的单矿物样品可以选择LA-MC-ICP-MS&EMPA联合法进行分析,需要高空间分辨率的样品建议使用fsLA-MC-ICP-MS法。  相似文献   

地面三维激光扫描在输电线路维护中的应用   总被引：1，自引：0，他引：1  

唐骐  陈世玉 《测绘信息与工程》2010,35(3):39-40

分析了地面三维激光扫描技术的基本工作原理,利用地面三维激光扫描技术实现了在高压区域的特殊测量。  相似文献   

小波分析在开采沉陷区地表裂缝信息提取的应用     

李亮  吴侃  陈冉丽  张舒 《测绘科学》2010,35(1)

三维激光扫描技术作为一种新的测量手段具有高效率、高精度的特点。其获得的海量的测量数据里面存在大量的有用信息,如何从这些信息里面提取出所关心的数据是目前研究的一个热点。本文根据开采沉陷区地表裂缝三维激光扫描数据的特点,将小波分析用于地表裂缝位置的判别。与现场实测数据的比较表明,合适的小波基能够有效地识别出地表裂缝的位置,为接下来的治理工作提供技术支持。  相似文献   

摄影测量激光点云空洞修补     

李海亮  邓非  李刚 《测绘科学》2010,35(5):101-102

为修补三维激光点云中的复杂空洞,本文提出了一种基于摄影测量原理的修补算法。与常规利用空洞与空洞周围点云的关系修补空洞的方法相比,该方法对于复杂空洞的修补可靠性更高,通用性更强。实验结果表明,该空洞修补算法适用于大面积、复杂的点云空洞,能较好地保持原三维物体的细节特征。  相似文献   

北京地区地壳三维结构的综合建模     

谭毅培  王伟君  齐诚  陈棋福 《震灾防御技术》2009,4(1):24-39

综合基础地理信息数据、数字化地质图、沉积层的地脉动探测结果、人工地震测深和宽角折射等多种资料,在对数据进行分析和整理的基础上,利用建模工具软件GoCAD,建立了北京地区（东经115．5°-117．5°,北纬39°—41°）地壳及上地幔顶部P波速度结构和地质界面模型。在模型建立的过程中,分析得到了人工地震剖面数据的地学统计特性,并设计了一种适合离散光滑插值（DSI）约束点权重的光滑估计方差,对模型的插值结果进行了质量评估。分析了北京地区地壳上地幔速度结构的特征,又将速度结构模型与层析成像结果进行对比,模型比较好地反映了北京地区的地下结构。  相似文献   

Terrestrial laser scanning used to determine the geometry of a granite boulder for stability analysis purposes   总被引：3，自引：0，他引：3  

J. Armesto  C. Ordez  L. Alejano  P. Arias 《Geomorphology》2009,106(3-4):271-277

In this paper we analyze the use of terrestrial laser scanning (TLS) technologies to determine the geometric features of a granite boulder. Accurate determination of these features is a key to performing a reliable stability analysis of the boulder.TLS has been demonstrated to have important advantages over traditional measurement techniques—such as, for example, direct methods based on the use of tapes or indirect methods such as topography or close-range photogrammetry. TLS equipment enables thousands of points to be accurately measured in minutes. In our study TLS-measured points were used to model the surface of a boulder. Geometric parameters were then calculated, namely, centre of gravity, volume of the boulder and dimensions of the boulder contact area with the ground. Taking into account mechanical and environmental factors, these parameters were used to calculate the safety factor of the boulder against toppling and sliding. Our results show that, when seismic activity in the region is taken into consideration, the boulder is borderline stable–unstable.  相似文献   

锦州地震台体应变数字化资料映震性能分析     

李京锦  明成山 《东北地震研究》2009,25(4):26-31

本文通过对体应变数字化资料进行分析、处理,结合具体实验,滤除干扰值,总结地震异常波形和映震情况。  相似文献   

Influence of survey strategy and interpolation model on DEM quality   总被引：2，自引：0，他引：2  

George L. Heritage  David J. Milan  Andrew R.G. Large  Ian C. Fuller 《Geomorphology》2009,112(3-4):334-344

Accurate characterisation of morphology is critical to many studies in the field of geomorphology, particularly those dealing with changes over time. Digital elevation models (DEMs) are commonly used to represent morphology in three dimensions. The quality of the DEM is largely a function of the accuracy of individual survey points, field survey strategy, and the method of interpolation. Recommendations concerning field survey strategy and appropriate methods of interpolation are currently lacking. Furthermore, the majority of studies to date consider error to be uniform across a surface. This study quantifies survey strategy and interpolation error for a gravel bar on the River Nent, Blagill, Cumbria, UK. Five sampling strategies were compared: (i) cross section; (ii) bar outline only; (iii) bar and chute outline; (iv) bar and chute outline with spot heights; and (v) aerial LiDAR equivalent, derived from degraded terrestrial laser scan (TLS) data. Digital Elevation Models were then produced using five different common interpolation algorithms. Each resultant DEM was differentiated from a terrestrial laser scan of the gravel bar surface in order to define the spatial distribution of vertical and volumetric error. Overall triangulation with linear interpolation (TIN) or point kriging appeared to provide the best interpolators for the bar surface. Lowest error on average was found for the simulated aerial LiDAR survey strategy, regardless of interpolation technique. However, comparably low errors were also found for the bar-chute-spot sampling strategy when TINs or point kriging was used as the interpolator. The magnitude of the errors between survey strategy exceeded those found between interpolation technique for a specific survey strategy. Strong relationships between local surface topographic variation (as defined by the standard deviation of vertical elevations in a 0.2-m diameter moving window), and DEM errors were also found, with much greater errors found at slope breaks such as bank edges. A series of curves are presented that demonstrate these relationships for each interpolation and survey strategy. The simulated aerial LiDAR data set displayed the lowest errors across the flatter surfaces; however, sharp slope breaks are better modelled by the morphologically based survey strategy. The curves presented have general application to spatially distributed data of river beds and may be applied to standard deviation grids to predict spatial error within a surface, depending upon sampling strategy and interpolation algorithm.  相似文献