Differential calibration of seismometers for measurement of rotation and strain

A method of correcting the seismometers’ responses discrepancy for differential measurements of strains and rotations in the seismic far field is proposed. The method concerns differential calibration of the whole seismometers’ array by electric current. A model of corrective filtering of the obtained differential signals in the Z domain is given. Two methods of the filter parameters’ estimation are introduced; they are based on the seismometers response to the calibration. A practical test of the methods — an analysis of a recorded seismic event — is added. Significant reduction of differences between simultaneous seismic recordings was obtained, which is interpreted as cleaning of differential signal from spurious elements.     

能量色散X射线荧光光谱仪现场快速测定多金属矿中17种组分

直接使用粉末样品,用Minipal 4便携式能量色散X射线荧光光谱仪测定多金属矿样品中的三氧化二铝、氧化镁、二氧化硅、氧化钾、氧化钙、三氧化二铁、硫、铜、锰、锌、铋、锑、铅、镓、银、砷、锡等17种组分,方法简便、快速,用多金属矿石国家一级标准物质验证,分析结果与标准值基本符合;精密度试验表明,各组分的相对标准偏差(RSD,n=12)均小于12%,能够满足矿山和野外现场快速测定的要求。     

便携式声波钻机在河道堤防勘探中应用分析研究

便携式声波钻机具有取样连续完整、轻便、场地适应能力强、用工少、节能高效等特点,在河道堤防勘探中具有独特优势。     

HC600型全液压动力头便携式钻机在陇东南山区生产应用效果及经济性分析

通过HC600型全液压动力头便携式钻机在武山温家沟金矿区、文县筏子坝外围铜矿区进行NQ、BQ型金刚石绳索取心钻探的效果,分析了全液压动力头便携式钻机相对于立轴式钻机的优点、不足及其经济性,提出全液压动力头便携式钻机在陇东南山区的适用性及我国地质岩心钻机发展的趋向。     

移动终端地理信息系统在广东省政务管理中的应用

随着科技的发展,移动终端(手机、平板电脑等)已逐渐成为了人们日常生活工作不可或缺的工具,利用移动终端更好的共享地理信息不论是对政务工作还是日常生活都会起到事半功倍的作用。本文主要介绍通过移动终端IOS和Android平台实现广东省地理信息公共平台的开发以及应用情况。     

地震台阵流动地震仪的检测与标定方法研究

流动地震仪组成的台阵观测系统已经成为地下结构、物性探测的基本工具,高质量观测数据的获取是以地震仪的性能为基础的。本文结合中国地震科学探测台阵系统建设与维护实践,介绍了科学探测台阵系统采用的几项检测标定技术,包括超低频振动台标定、仪器一致性组网检测、白噪声标定和现场快速仪器检测,形成了一套适合地震流动台阵仪器的检测标定方法,并在观测实践中获得较好的应用。     

某石油化工场地土层挥发性有机物的污染特征

在调查华北平原一个污染年限超过35年的石油化工场地时,采用便携式仪器土层测气方法,快速、准确地测定了场地内40多个钻孔不同深度土层中挥发性有机物(VOCs)的浓度。基于对场地地质水文地质条件的认识,以及通过对大量数据的分析对比和应用空间变异分析方法,得出了对场地土层介质中VOCs污染特征的如下认识:(1)土层VOCs浓度的垂向变化可概括为污染源淋滤型、包气带扩散污染型、地下水波动带污染型和混合污染型四种污染类型;(2)在包气带砂土层和粉土层中,VOCs的扩散规律可近似用指数模型描述;(3)包气带土层中VOCs优先积聚在渗透性强的砂性土层中,砂土层中VOCs浓度是粉土层中VOCs浓度的1.5～12倍,平均3.76倍;(4)土层VOCs浓度的水平变异性表现为包气带土层的变异性要比地下水波动带土层大,且水平变异性能在25m尺度内得到充分显示;而土层VOCs浓度的垂向变异性随地而异,变化复杂,很难用统一的一个量化尺度来表征。本文对这一典型污染场地的剖析,有助于从事污染场地调查人员认识我国华北平原石油化工类场地的污染特征,并为调查与治理类似污染场地提供技术依据。     

Using three different approaches of OSL for the study of young fluvial sediments at the coastal plain of the Usumacinta–Grijalva River Basin,southern Mexico

We use three different approaches of optically stimulated luminescence (OSL) to study young fluvial sediments located at the main channels of one of the largest fluvial systems of North America: the Usumacinta–Grijalva. We use the pulsed photo‐stimulated luminescence (PPSL) system also known as portable OSL reader, full OSL dating and profiling OSL dating in samples extracted from vertical sediment profiles (n = 9) of riverbanks to detect changes in depositional rates of sediments and to obtain the age of the deposits. The results of the PPSL system show that the luminescence signals of vertical sediment profiles highly scattered from the top to the bottom contrast with the luminescence pattern observed on well‐reset sequences of fluvial deposits where luminescence increase from the top to the bottom of the profile. The profiling and full OSL ages yielded large uncertainty values on their ages. Based on the inconsistencies observed in both ages and luminescence patterns of profiles we suggest that these fluvial deposits were not fully reset during their transport. As an explanation, we propose that in the Usumacinta and Grijalva rivers the cyclonic storms during the wet season promote the entrainment of large volumes of sediments due to high‐erosional episodes around the basin resulting from hyper‐concentrated and turbid flows. We conclude that the PPSL, profiling and full OSL dating of sediments are useful tools to quantify and to assess the depositional patterns in fluvial settings during the Holocene. These techniques also can yield information about sites where increases in the sediment load of rivers may produce poorly resetting of grains affecting the results of OSL dating. Copyright © 2015 John Wiley & Sons, Ltd.     

A workflow for exploration sampling in regolith-dominated terranes using portable X-ray fluorescence: comparison with laboratory data and a case study

This paper presents and validates a workflow that provides for the rapid collection of reliable and robust portable X-ray fluorescence (pXRF) data in a regolith-dominated exploration setting. The analysis of regolith material by pXRF is challenging because of its variable Fe content (e.g. 0 to >70 wt%) that results in large matrix effects, which can be mitigated with appropriate standards. Here, we present a dataset from the Western Mount Isa Inlier, Queensland, Australia, comprising soil, lag, rock and rotary air blast (RAB) samples. In the soil dataset, comparison of the laboratory and pXRF datasets for Cu, Pb and Zn have R² > 0.9, and Cu and Zn fall within 2% of the laboratory data, while Pb is 77% less than the corresponding laboratory analyses. Iron, Al, K and Ca by pXRF perform reasonably well when compared with the laboratory data (R² = 0.59 for Al, R² > 0.9 for Fe, K and Ca, <25% variation from the laboratory data), while Mn, Rb and Sr have very good correlations (<8% variation) with R² > 0.94. Titanium, Zr, Ni, Cr and As have poorer comparisons. Overall, the RAB dataset shows similar trends with Cu overestimated by 17%, Zn underestimated by 4% and Pb overestimated by 69%; R² for all elements is >0.92. Since no suitable standards are available, the solid rock dataset was uncorrected; despite this limitation, the dataset shows good correlations with the laboratory data for many elements, and Cu is overestimated by 9.8% with an R² = 0.87. The poor analytical performance of Pb in all datasets is associated with erroneous Bi concentrations being reported by the pXRF unit. When high Fe and Pb amounts are present in a sample, erroneous Pb and Bi concentrations are reported, owing to a pile-up of the Fe K_α peak (6.405 keV) at ～12.8 keV, which is proximal to the Pb L_β (12.614 keV) and Bi L_β (13.023 keV) peaks. Despite the care that is required in validating data, by using pXRF there is substantial opportunity for dynamic exploration campaigns in regolith-dominated terranes with rapid turnaround times, additional elements that may not otherwise be analysed for and low analytical costs. Decisions to stop, continue or infill drill holes while the drill rig is present can be made in near-real time, and not after laboratory results are available and the drill rig has left the area.