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151.
Haosheng Wu Roman Bttger Frdric Couffignal Jens Gutzmer Joachim Krause Frans Munnik Axel D. Renno Ren Hübner Michael Wiedenbeck Ren Ziegenrücker 《Geostandards and Geoanalytical Research》2019,43(4):531-541
Although electron probe microanalysis and secondary ion mass spectrometry are widely used analytical techniques for geochemical and mineralogical applications, metrologically rigorous quantification remains a major challenge for these methods. Secondary ion mass spectrometry (SIMS) in particular is a matrix‐sensitive method, and the use of matrix‐matched reference materials (RMs) is essential to avoid significant analytical bias. A major problem is that the number of available RMs for SIMS is extremely small compared with the needs of analysts. One approach for the production of matrix‐specific RMs is the use of high‐energy ion implantation that introduces a known amount of a selected isotope into a material. We chose the more elaborate way of implanting a so‐called ‘box‐profile’ to generate a quasi‐homogeneous concentration of the implanted isotope in three dimensions, which allows RMs not only to be used for ion beam analysis but also makes them suitable for EPMA. For proof of concept, we used the thoroughly studied mineralogically and chemically ‘simple’ SiO2 system. We implanted either 47Ti or 48Ti into synthetic, ultra‐high‐purity silica glass. Several ‘box‐profiles’ with mass fractions between 10 and 1000 μg g?1 Ti and maximum depths of homogeneous Ti distribution between 200 nm and 3 μm were produced at the Institute of Ion Beam Physics and Materials Research of Helmholtz‐Zentrum Dresden‐Rossendorf. Multiple implantation steps using varying ion energies and ion doses were simulated with Stopping and Range of Ions in Matter (SRIM) software, optimising for the target concentrations, implantation depths and technical limits of the implanter. We characterised several implant test samples having different concentrations and maximum implantation depths by means of SIMS and other analytical techniques. The results show that the implant samples are suitable for use as reference materials for SIMS measurements. The multi‐energy ion implantation technique also appears to be a promising procedure for the production of EPMA‐suitable reference materials. 相似文献
152.
Jin Li Suo‐han Tang Xiang‐kun Zhu Zhi‐hong Li Shi‐Zhen Li Bin Yan Yue Wang Jian Sun Yao Shi Aiguo Dong Nick S. Belshaw Xingchao Zhang Sheng‐ao Liu Ji‐hua Liu Deli Wang Shao‐yong Jiang KeJun Hou Anthony S. Cohen 《Geostandards and Geoanalytical Research》2019,43(1):163-175
Iron, Cu and Zn stable isotope systems are applied in constraining a variety of geochemical and environmental processes. Secondary reference materials have been developed by the Institute of Geology, Chinese Academy of Geological Sciences (CAGS), in collaboration with other participating laboratories, comprising three solutions (CAGS‐Fe, CAGS‐Cu and CAGS‐Zn) and one basalt (CAGS‐Basalt). These materials exhibit sufficient homogeneity and stability for application in Fe, Cu and Zn isotopic ratio determinations. Reference values were determined by inter‐laboratory analytical comparisons involving up to eight participating laboratories employing MC‐ICP‐MS techniques, based on the unweighted means of submitted results. Isotopic compositions are reported in per mil notation, based on reference materials IRMM‐014 for Fe, NIST SRM 976 for Cu and IRMM‐3702 for Zn. Respective reference values of CAGS‐Fe, CAGS‐Cu and CAGS‐Zn solutions are as follows: δ56Fe = 0.83 ± 0.07 and δ57Fe = 1.20 ± 0.13, δ65Cu = 0.57 ± 0.06, and δ66Zn = ?0.79 ± 0.12 and δ68Zn = ?1.65 ± 0.24, respectively. Those of CAGS‐Basalt are δ56Fe = 0.15 ± 0.07, δ57Fe = 0.22 ± 0.10, δ65Cu = 0.12 ± 0.08, δ66Zn = 0.17 ± 0.13, and δ68Zn = 0.34 ± 0.26 (2s). 相似文献
153.
Vibor Roje 《Geostandards and Geoanalytical Research》2019,43(2):317-327
This paper is intended to be a constructive discussion of Fiket et al. (2017, Geostandards and Geoanalytical Research , 41 , 123–135), who dealt with the determination of major, trace and rare earth elements in several sediment and soil certified reference materials. In the present author's view, the paper by Fiket et al. (2017) suffers from a lack of reference to several publications in which somewhat similar results had already been reported. The present contribution therefore provides a comparison of previously published results with those of Fiket et al. for the CRMs soil NCS DC 77302 (GBW 07410), stream sediment NCS DC 73309 (GBW 07311), marine sediments MESS‐3 and NCS DC 75301 (GBW 07314) and estuarine sediment IAEA‐405. It is argued that this fuller consideration (a) allows critical evaluation of the quality of the results presented by Fiket et al. and (b) highlights the advantages of their work. Finally, attention is drawn to the (possible or real) problems that can arise during simultaneous determination of multiple trace elements. 相似文献
154.
Hideki Iwano Tohru Danhara Takashi Yuguchi Takafumi Hirata Masatsugu Ogasawara 《地学学报》2019,31(3):247-256
Anorthositic series apatites of the Duluth Complex, Minnesota, USA, have high spontaneous fission‐track densities of up to ~107 cm–2 and a homogeneous age of ~900 Ma, allowing high‐precision fission‐track dating based on LA–ICP–MS U analysis. Absolute fission‐track dating, track‐length measurement and chemical composition analysis were performed to evaluate a cooling history, which is essential for age reference materials. Preliminary inverse modelling for a sample with a shortened track‐length distribution yielded a monotonic cooling history from ~100°C at 925 Ma. The apatites incur an over‐etching problem when employing the commonly used etching protocol involving 5.5 M HNO3. 相似文献
155.
志愿者地理信息数据大都依靠志愿者上传,数据质量未知,阻碍了志愿者地理信息的广泛应用,因此是志愿者地理信息首要解决的问题。本文分析了影响志愿者地理信息质量的相关因素和基于参考数据评价方法的相关研究成果,在此基础上提出了一种基于参考数据的志愿者地理信息质量评价方法,以最常见的数据完整性和数据精度作为质量评价的质量元素,详细论述了这两种质量元素的内涵。针对数据完整性评价,提出了与匹配相结合的几何数据完整性度量方法和基于属性项饱和度的属性数据完整性度量方法;针对几何数据精度评价,提出了基于变缓冲区的度量方法。然后给出了该评价方法的一般流程。最后,以深圳市Open Street Map数据为例,选取最新导航数据作为参考数据进行试验验证。实验结果表明,深圳市Open Street Map数据点要素完整性较差,但是线要素完整性与精度都非常高,可以作为基础地理信息的更新数据源。 相似文献
156.
针对航空遥感惯性稳定平台中所受到的不平衡力矩等所引起的成像载荷不稳定导致无法获取高分辨率遥感数据的问题,提出了在平台控制系统中应用基于模型参考的自适应比例-积分-微分控制方法。根据需求设计出参考模型,将参考系统输出与实际系统输出之间的误差输入到自适应PID调节器,实时调整PID参数,对误差进行实时校正,以达到抑制不平衡力矩扰动、提高稳定平台稳定精度的目的。对所提出的模型参考自适应控制方法进行了仿真验证,结果表明:相对传统PID方法,模型参考自适应控制器对偏心力矩等主要干扰具有很好的抑制作用,系统输出能够很好地跟踪姿态变化,系统稳定精度得到显著提高。 相似文献
157.
罗京 《测绘与空间地理信息》2017,(1)
针对城市交通部门事故管理系统中存在道路数据不独立以及发布的事故信息易读性差导致应急部队无法准确定位事故地点进行救援的问题,基于公路的线性特征,结合GIS对地理数据的多样操作功能,提出路段名+特征参考点的一维定位表达方法。将线性参照系理论应用到以综合车道为公路模型的空间数据管理模式中,建立基于线性参照系的城市公路事故信息发布系统,实现二维坐标向一维坐标转换、降低数据冗余、实现事故地点的快速定位以及对定位的事故信息进行发布。 相似文献
158.
针对面阵影像与线阵影像之间存在的尺度、旋转等几何差异所导致的难以高效获得稳定可靠匹配点问题,该文提出了一种稳健的面阵影像与线阵影像匹配方法。算法分为3个阶段:(1)对影像进行尺度、旋转预处理,消除影像间的尺度和旋转差异;(2)用Harris算子提取特征点,进行逐层金字塔匹配,在最底层影像上进行最小二乘匹配获取精匹配点,利用随机抽样一致算法获取准确性较高的匹配点;(3)对准确性较高的匹配点分区,构建4块匹配区域,根据每块区域的匹配点计算重心,以此4块区域的重心作为匹配基准点和基准方向,重约束初始匹配结果。通过多组面阵影像与线阵影像数据实验结果,验证了该方法的可行性和有效性,可为后续空中三角测量及相关应用提供可靠的匹配点。 相似文献
159.
160.
使用SRTM DEM、土地覆被、冻融侵蚀、河流沟谷等多源数据,对区分海拔等级的指标地物作了具体分析,以指标地物的平均海拔为依据,通过分级指标对象(如冰川、林线)分布高程重合或贴近的多条等高线圈形成分级等高平面,对陆地地貌进行切割划分,用每组指标对象偏离等高平面的值作为控制量(控制点),插值重构分级参考曲面。该方案最大限度突出指标的地理意义,形成的海拔分级结果与中国地理系统分布特征更为贴近,可以为中国大尺度地貌基本形态的划分提供参考。 相似文献