铁同位素的MC-ICP-MS测定方法与地质标准物质的铁同位素组成

详细报道了在低分辨和高分辨模式下运用MC-ICP-MS进行Fe同位素比值高精度测试的方法,对Fe同位素测定过程中谱峰干扰、基质效应、浓度效应、仪器测试的长期重现性等问题进行了评估,并对两种运行模式的测试结果进行了对比.在95%的可信度范围内,所建方法的外部精度优于0.5ε/ainu,达到国际同类实验室的先进水平,并且低分辨和高分辨两种模式下获得的Fe同位素测试结果是一致的.在此基础上对国家地质标准物质GBW07105(玄武岩)和GBW 07111(花岗闪长岩)进行了Fe同位素测定.相对于Fe同位素国际标样IRMM-014,GBW07105的Fe同位素成分为:ε57Fe=1.9±0.3(20),ε56Fe=1.3±0.2(2σ),ε57/56Fe=0.6±0.1(2σ);GBW 07111的Fe同位素成分为:ε57Fe=1.8±0.4(2σ),ε56Fe=1.2±0.2(2σ),ε57/56Fe=0.6±0.1(2σ).     

Study on low‐strain integrity testing of pipe‐pile using the elastodynamic finite integration technique

This study focuses on the three‐dimensional (3‐D) characteristics of wave propagation in pipe‐pile using elastodynamic finite integration technique. First, a real 3‐D pile‐soil model in cylindrical coordinate system is presented. Then, the governing equations are established. With the boundary and initial conditions, the numerical solution is obtained. The accuracy and feasibility of the self‐written code are further verified via comparing with the measured data. Velocity histories at different angles of pile top and pile tip are illustrated, and the snapshots reflecting the 3‐D characteristics of wave propagation are given. It shows that the interferences of Rayleigh waves can confuse the result interpretation for pile integrity testing. The increase of hammer contact time can effectively mitigate the interferences, and the interferences of Rayleigh waves are weakest at an angle of 90° from where hammer hits. Besides, surrounding soil can partly mitigate the wave interferences. Copyright © 2012 John Wiley & Sons, Ltd.     

基于变换域方法抑制线性调频干扰的GPS接收机设计

GPS接收机的信号通常很微弱,很容易受到有意或无意的干扰。对于线性调频干扰,在GPS接收机中很难用单一的时域或频域方法消除,因为线性调频干扰不同于一般的宽带或窄带干扰。另外线性调频干扰在变换域有不同于GPS C/A码的显著特征,基于此特点设计了一种在变换域抑制线性调频干扰的GPS接收机。分析了线性调频干扰在变换域的特征,仿真结果验证了这种设计方法的可行性。     

辽宁省数字化形变观测自然干扰分析

对数字形变观测过程中辽宁丹东地震台、营口地震台、抚顺地震台、朝阳地震台DSQ水管仪、SS-Y伸缩仪存在的自然干扰现象进行研究,对其机理和数据形态作了对比分析,为快速、准确地判别自然干扰提供了科学依据。     

航空放射性测量中的一项重要工作—飞机改装

为了发挥航测仪器的性能和提高测量精度,用于航空放射性测量的飞机必须进行必要的改装,改装工作除了保证航测仪器安装可靠、牢固之外,还要使飞机对仪器的磁干扰,放射性干扰和电干扰降低到允许的水平。本文对运五和运十二飞机存在的干扰情况进行了讨论,并就如何消除这些干扰提出了切合实际的改装方案。     

Trace Element Determination by ICP-AES and ICP-MS: Developments and Applications Reported During 2004 and 2005

This review describes significant developments in trace element determination using inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS) that were reported in 2004 and 2005. It focuses on the application of ICP techniques to geological and environmental samples; fundamental studies in ICP-MS and ICP-AES instrumentation are not included. The literature reviewed indicated that the majority of new publications concerned advances in ICP-MS analysis rather than ICP-AES. However, ICP-AES developments are still being published, particularly in the areas of sample preconcentration and sample introduction. The trend in increasing publication of developments in hyphenated speciation techniques looks set to persist as knowledge of elemental speciation becomes critical for many environmental studies. Collision or reactions cells were the most reported technique for spectral interference removal in ICP-MS, probably reflecting the growing adoption of cell instruments in laboratories during the last few years.     

An optimized chemiluminescence detector for tropospheric NO measurements

A detector for the chemiluminescent measurement of NO in background air is described. A large reduction of interferences is achieved by using a stabilized ozone generator which allows operation of the instrument at lower O₃ concentrations. Purification and humidification of the O₃ stream further reduces interferences and shortens the instrumental clean-up time, which is important for aircraft missions. From a series of laboratory tests and from measurements performed aboard an aircraft it is demonstrated that the remaining interferences are acceptable for measurements in the undisturbed troposphere. In particular, no remnant NO signal is observed in clean air at night. During flight, a detection limit (2) of 20 ppt is achieved for a 1 min integration time.     

Trace Element Determination by ICP‐AES and ICP‐MS: Developments and Applications Reported During 2006 and 2007

This review describes developments in trace element determination using inductively coupled plasma‐atomic emission spectrometry (ICP‐AES) and inductively coupled plasma‐mass spectrometry (ICP‐MS) that were reported in 2006 and 2007. It focuses on the application of ICP techniques to geological and environmental samples; fundamental studies in ICP‐MS and ICP‐AES instrumentation have largely been ignored. New advances in ICP‐MS and ICP‐AES were incremental over this period, partly because both techniques are now well‐established. A continuing shift towards the hyphenation of low‐flow separation techniques has sparked activity in the development of appropriate low‐flow interfaces, and papers discussing interference removal also contribute significantly to the volume of research for both ICP‐AES and ICP‐MS. Whereas the majority of new ICP publications concerned advances in ICP‐MS analysis rather than ICP‐AES, development for ICP‐AES still occurs in almost all areas, particularly in sample introduction and hyphenated techniques.     

High‐Precision Cd Isotope Measurements of Soil and Rock Reference Materials by MC‐ICP‐MS with Double Spike Correction

This study presents a high‐precision Cd isotope measurement method for soil and rock reference materials using MC‐ICP‐MS with double spike correction. The effects of molecular interferences (e.g., ¹⁰⁹Ag¹H⁺, ⁹⁴Zr¹⁶O⁺, ⁹⁴Mo¹⁶O⁺ and ⁷⁰Zn⁴⁰Ar⁺) and isobaric interferences (e.g., Pd, In and Sn) to Cd isotope measurements were quantitatively evaluated. When the measured solution has Ag/Cd ≤ 5, Zn/Cd ≤ 0.02, Mo/Cd ≤ 0.4, Zr/Cd ≤ 0.001, Pd/Cd ≤ 5 × 10^?5 and In/Cd ≤ 10^?3, the measured Cd isotope data were not significantly affected. The intermediate measurement precision of pure Cd solutions (BAM I012 Cd, Münster Cd and AAS Cd) was better than ± 0.05‰ (2s) for δ^114/110Cd. The δ^114/110Cd values of soil reference materials (NIST SRM 2709, 2709a, 2710, 2710a, 2711, 2711a and GSS‐1) relative to NIST SRM 3108 were in the range of ?0.251 to 0.632‰, the δ^114/110Cd values of rock reference materials (BCR‐2, BIR‐1, BHVO‐2, W‐2, AGV‐2, GSP‐2 and COQ‐1) varied from ?0.196‰ to 0.098‰, and that of the manganese nodule (NOD‐P‐1) was 0.163 ± 0.040‰ (2s, n = 8). The large variation in Cd isotopes in soils and igneous rocks indicates that they can be more widely used to study magmatic and supergene processes.