Developments at ISO/REMCO and its Impact on the Production and Use of Geological Reference Materials

During the past decade the work of ISO/REMCO, the International Organization for Standardization’s Technical Committee on Reference Materials, was dedicated to achieving global harmonisation, and true involvement of the member countries. The first major accomplishment was the clarification of the terminology in the definitions for reference material and certified reference material, which were published as an amendment to ISO Guide 30 in 2008. The next milestone was the recognition that ISO Guide 34 (‘General requirements for the competence of reference material producers’) be used in conjunction with ISO/IEC 17025 for the accreditation of reference material producers. The third edition of ISO Guide 34 published in November 2009, clarifies the acceptable procedures for the certification of reference materials. This paper will discuss the role of ISO/REMCO in formalising the procedures for the accreditation of reference material producers and the evolution of the terms reference material and certified reference material. The paper will conclude with a case study, where a primary method in a single laboratory – one of the recognised acceptable metrologically valid procedures according to ISO Guide 34 – was used for the certification of reference materials. The reference materials are South African Reference Material SARM 2 (Syenite), SARM 3 (Lujavrite) and SARM 4 (Norite) from the suite of six NIMROCs that were originally certified by the Council for Mineral Technology (MINTEK) in South Africa in the 1970s.     

电感耦合等离子体质谱法测定高海拔地区地热水中的微量元素

西藏地区地热水矿化度较高,且西藏地区海拔高分压低,造成电感耦合等离子体质谱/发射光谱仪(ICP-MS/OES)的工作条件与低海拔地区不同,因此测定样品时无法采用与低海拔地区相同的测定方法。本文通过优化仪器的工作条件、加入内标元素和建立干扰校正方程等方法,消除了低分压和高矿化度的影响,建立了ICP-MS同时测定高海拔地区地热水中的12种微量元素的方法,并对地热水中的放射性元素铀进行检测。测定元素校准曲线的相关系数都在0.9995以上,方法检出限为0.012~0.128μg/L,相对标准偏差(RSD)为1.2%~6.8%,样品加标回收率为95.7%~106.5%。结合本课题组前期的研究成果,本文提出,ICP-MS法更适合较高矿化度地热水中微量和痕量元素的测定,ICP-OES法则适用于主量元素的测定,两种方法的结合,可建立高海拔地区地热水的分析技术体系。     

Simple features of mantle-wide convection and the interpretation of lower-mantle tomograms

Simple fluid dynamic constraints aid in the interpretation of lower mantle tomograms. The geothermal gradient away from slabs and plumes is subadiabatic between the upper (lithosphere) and lower (D″) boundary layers by ～400 K. Slabs widen proportionally with the square root of the viscosity as they sink through the lower mantle. The time scale for the persistence of slab graveyards at the base of the mantle is comparable to the time for plate motions to reorganize ～120–200 Myr. At most a few starting plume heads currently exist in the lower mantle. Tomographic inversions may include more sophisticated numerical-modeling versions of these constraints.     

1985国家高程基准的研究

本文是1976年以来对我国高程基准研究工作的总结报告,研究结果已被我国测绘系统采用,计算精度满足了国家大地测量精度的要求     

Méthodes de quantification des transferts de matiére par les fluides dans les roches métamorphiques déformées

Résumé

Les transferts de matière par les fluides se marquent dans les roches métamorphiques par des différenciations chimiques et minéralogiques. Une approche quantitative des relations entre transferts de matière et déformation passe par l’étude de ces différenciations dans des structures présentant soit un gradient continu de l’intensité de la déformation, soit des sites structuraux distincts. Dans ces structures, la roche initiale est souvent préservée dans des zones protégées. Des bilans de matière, par comparaison de cette analyse initiale avec les différentes roches déformées sont effectuées. Une référence chimique, minéralogique ou volumique est choisie dans des diagrammes où sont reportés les gains ou les pertes des constituants de la roche pour les différentes valeurs possibles de son changement de volume. Les quantités de matière transférée et les variations de volume sont alors lues directement dans les diagrammes ou calculées par des relations générales. Dans des diagrammes de variation chimique, ces résultats sont reportés pour chaque roche transformée, en fonction d’un paramètre de différenciation : intensité de la déformation, de la transfonnation chimique ou minéralogique, position dans la structure de déformation. Suivant les cas, ces diagrammes donnent l’évolution de la mobilité des éléments au cours de la déformation ou de la différenciation chimique, les gradients de changement de volume ou les variations de masse dans la structure de déformation étudiée. Des exemples d’un bilan minéralogique et volumique entre flancs et charnière d’un pli, d’un bilan chimique dans une zone de cisaillement et de l’écriture d’une réaction métamorphique sont présentés. Les différentes étapes d’une approche quantitative des relations entre transfert de matière et déformation sont récapitulés.     

Uber,Public Transit,and Urban Transportation Equity: A Case Study in New York City

With the explosive growth of Uber and other mobility service providers, their influences on urban mobility have attracted attention from both researchers and policy circles alike, yet few quantitative studies have been conducted on the topic. Using Uber pickup data in New York City in 2014, this article investigates the spatiotemporal relationship between Uber and public transit using buffer analysis and spatial cross-correlation analysis and assesses Uber’s impact on urban transportation equity with the Gini coefficient and correlation analysis. Our results confirm previous arguments that Uber both complements and competes with public transit, but competition is more prevalent in New York City. Specifically, Uber competes with public transit during most hours of the day and in areas with good public transit coverage, whereas it complements public transit at midnight and in places with insufficient public transit services. The distribution of Uber services is highly unequal, and Uber’s role in improving transport equity is insignificant. Correlation analysis shows that there tend to be fewer Uber pickups in low-income areas, which diverges from previous studies suggesting that Uber serves low-income areas well. In addition, a weak negative correlation is detected between the number of Uber pickups and the percentage of minorities.     

Lithium Isotope Composition of Ultramafic Geological Reference Materials JP‐1 and DTS‐2

An organic solvent‐free two‐step column procedure is presented that provided robust, high yield and super clean separation of Li from silicate rock sample matrices. The measured δ⁷Li value for BHVO‐2 of +4.29 ± 0.23‰ (1s) is comparable with the reported values. The δ⁷Li values for GSJ JP‐1 (+3.14 ± 0.41‰, 1s) and USGS DTS‐2 (+4.91 ± 0.34‰, 1s) presented here provide new reference values for ultramafic rock reference materials.     

Current Behaviour and Dynamics of the Lowermost Italian Glacier (Montasio Occidentale,Julian Alps)

Smaller glaciers (<0.5 km²) react quickly to environmental changes and typically show a large scatter in their individual response. Accounting for these ice bodies is essential for assessing regional glacier change, given their high number and contribution to the total loss of glacier area in mountain regions. However, studying small glaciers using traditional techniques may be difficult or not feasible, and assessing their current activity and dynamics may be problematic. In this paper, we present an integrated approach for characterizing the current behaviour of a small, avalanche‐fed glacier at low altitude in the Italian Alps, combining geomorphological, geophysical and high‐resolution geodetic surveying with a terrestrial laser scanner. The glacier is still active and shows a detectable mass transfer from the accumulation area to the lower ablation area, which is covered by a thick debris mantle. The glacier owes its existence to the local topo‐climatic conditions, ensured by high rock walls which enhance accumulation by delivering avalanche snow and reduce ablation by providing topographic shading and regulating the debris budget of the glacier catchment. In the last several years the glacier has displayed peculiar behaviour compared with most glaciers of the European Alps, being close to equilibrium conditions in spite of warm ablation seasons. Proportionally small relative changes have also occurred since the Little Ice Age maximum. Compared with the majority of other Alpine glaciers, we infer for this glacier a lower sensitivity to air temperature and a higher sensitivity to precipitation, associated with important feedback from increasing debris cover during unfavourable periods.