‘Box‐Profile’ Ion Implants as Geochemical Reference Materials for Electron Probe Microanalysis and Secondary Ion Mass Spectrometry

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.     

基于核酸适配体功能化石墨纳米颗粒荧光探针的17β-雌二醇快速检测方法

为构建一种能够简单、快速、特异性检测复杂环境水体中雌激素污染的方法,利用石墨纳米颗粒作为荧光淬灭剂、核酸适配体作为识别元素、1-芘丁酸N-羟基琥珀酰亚胺酯作为异型双功能交联剂,构建了一种新型纳米荧光探针;并探究了构建荧光探针时核酸适配体初始投加量和荧光探针投加量对雌二醇检测的影响及最佳实验条件下检测雌二醇的效果和特异性。实验结果表明：核酸适配体能成功修饰在石墨纳米颗粒表面形成的稳定荧光探针;构建荧光探针时核酸适配体的最佳初始投加量为1.0 μmol/L;检测雌二醇时,荧光探针的最佳投加量为4 μg/mL;最佳实验条件下,相对荧光强度与雌二醇的质量浓度在50~800 ng/mL范围内成正比,最低检测限为34.5 ng/mL,且该荧光探针能实现对雌二醇的简单、快速、特异性检测。     

Effects of the peat acid digestion protocol on geochemically and morphologically diverse tephra deposits

Tephra shards for electron probe microanalysis are most efficiently extracted from peat using acid digestion, which removes organic material that hinders density separation methods. However, strong acids are known to alter glass chemical compositions, and several studies have examined how acid digestion affects rhyolitic volcanic glass. The focus on rhyolitic tephra in these studies leaves considerable uncertainty, as the dissolution rates of natural glasses (including tephra) are determined by the chemical composition and surface area/volume ratio, both of which vary in tephra deposits. Here, we use duplicate samples of basaltic, trachydacitic and rhyolitic tephra to examine physical and geochemical alteration following acid digestion. Scanning electron microscope imagery reveals no discernible degradation of glass surfaces, and electron probe microanalysis results from duplicate samples are statistically indistinguishable. These findings suggest the acid digestion protocol for organic peats does not significantly alter glass geochemistry regardless of shard morphologies or geochemical compositions.     

福建东山岛矿产资源开发利用与生态环境保护初论

就东山岛在水、砂、石、土的开发利用中存在的问题,阐述了开发利用矿产与保护生态环境之间的辩证关系,提出东山县应做好矿产资源开发利用与“建设港口旅游城市”的规划,走资源节约型的发展海洋经济建设的新路子,促进东山县经济的可持续发展。     

Influence of environments of coal deposition on phosphorous accumulation in a high latitude, northern Alaska, coal seam

Although phosphorus is a very important biogenic element, its concentration in coal is generally low. Phosphorus (P) concentrations typically range from 0.001% to 0.229% in raw coals of the contiguous 48 states [Glick, D.C., Davis, A., 1984. Variability in the inorganic content of United States coals—a multivariate statistical study of final report, Part 10 (DOE-30013-Flo) to the US Dept. of Energy under contract no. DE-AC22-80PC 30013, 404 pp.]. Some Alaskan coal seams contain horizons that are unusually high in phosphorus. The present paper focuses on a bituminous coal from northern Alaska, where 0.15 m subsections of this coal seam have shown high phosphorous in certain subsections. In order to investigate the lateral extent of such high phosphorous bands in coal, the authors obtained three drill cores up to 3 km apart from the coal seam. A detailed investigation of the cores was undertaken to determine the nature and mode of occurrence of phosphorous minerals. Maceral composition allowed interpretation of environments of coal deposition. Acid-extractable phosphorous analysis of the subsections identified the high phosphorous horizons. Electron microprobe analyses identified the phosphorous mineral as crandallite. Correlation of high phosphorous intervals with corresponding environments of deposition suggests that phosphorous precipitation is promoted by an oxidizing environment with a lowered water table during the peat stage. A study of thin sections from high phosphorous samples showed that crandallite is associated with structured vitrinite and as cell fillings in fusinite. The study confirms the potential for using high phosphorous horizons for the correlation of coal seams, as noted in previous work by the authors (Rao and Walsh, 1997). A high phosphorous horizon is found at 0.45 m above the bottom of the seam in all of the drill holes, indicating a uniformity of the coal forming environment and the availability of crandallite constituent elements over the entire 3 km. The uniformity of high phosphorous concentrations through the top 2 m of the three drill holes also shows a distinct correlation.     

Further results for astrophysics from the cosmology within the framework of the Projective Unified Field Theory

Recently the 5‐dimensional Projective Unified Field Theory (PUFT) of the author (Schmutzer 1995a, Schmutzer 1995b) has been applied to a closed homogeneous isotropic cosmological model with the result of a cosmology without big bang (Schmutzer 1999a, Schmutzer 1999b). Continuing this approach, in this paper following subjects are treated: recalculation of numerical values of cosmological quantities, exact solution of the field equations to a point‐like body, motion of a test body in such a field, definition of the empirical effective gravitational factor (“constant”), Einstein effects compared to the empirical situation, adiabatic approximation of the motion of an orbiting testbody under the influence of the expanding cosmos (transition of the ellipses to circles, decrease of the radius of the orbiting bodies, decrease of the excentricity, increase of the frequency of orbiting objects etc.), heat production in a moving body induced by the cosmological expansion with application to various cosmic objects.     

Electron Probe Microanalysis of Bromine in Minerals and Glasses with Correction for Spectral Interference from Aluminium,and Comparison with Microbeam Synchrotron X‐Ray Fluorescence Spectrometry

The strong spectral interference between Br‐ and Al‐induced X‐ray lines hampers the utilisation of electron probe microanalysis (EPMA) for measuring Br mass fractions in Al‐bearing minerals and glasses. Through measuring Br‐free Al‐bearing materials, we established an EPMA method to quantify the overlap from AlKα on BrLβ, which can be expressed as a linear function of the Al₂O₃ content. The count rate of the BrLβ peak signal was enhanced by high beam currents and long measurement times. Application of this EPMA method to Al‐ and Br‐bearing materials, such as sodalite and scapolite, and to five experimental glasses yielded Br mass fractions (in the range of 250–4000 μg g^?1) that are consistent with those measured by microbeam synchrotron X‐ray fluorescence (μ‐SXRF) spectrometry. The EPMA method has an estimated detection limit of ~ 100–300 μg g^?1. We propose that this method is useful for measuring Br mass fractions (hundreds to thousands of μg g^?1) in Al‐bearing minerals and glasses, including those produced in Br‐doped experiments. In addition, the natural marialitic scapolite (ON70) from Mpwapwa (Tanzania) containing homogeneously distributed high mass fractions of Br (2058 ± 56 μg g^?1) and Cl (1.98 ± 0.03% m/m) is an ideal reference material for future in situ analyses.     

Characteristics of the 2000 fissure eruption and lava flow fields at Mount Cameroon volcano,West Africa: a combined field mapping and remote sensing approach

This study focuses on the compound pahoehoe lava flow fields of the 2000 eruption on Mount Cameroon volcano, West Africa and it comprehensively documents their morphology. The 2000 eruption of Mount Cameroon took place at three different sites (sites 1, 2 and 3), on the southwest flank and near the summit that built three different lava flow fields. These lava flow fields were formed during a long‐duration (28th May–mid September) summit and flank eruption involving predominantly pahoehoe flows (sites 2 and 3) and aa flows (site 1). Field observations of flows from a total of four cross‐sections made at the proximal end, midway and at the flow front, have been supplemented with data from satellite imagery (SRTM DEM, Landsat TM and ETM+) and are used to offer some clues into their emplacement. Detailed mapping of these lava flows revealed that site 1 flows were typically channel‐fed simple aa flows that evolved as a single flow unit, while sites 2 and 3 lava flow fields were fed by master tubes within fissures producing principally tube‐fed compound pahoehoe flows. Sites 2 and 3 flows issued from ∼ 33 ephemeral vents along four NE–SW‐trending faults/fissures. Pahoehoe morphologies at sites 2 and 3 include smooth, folded and channelled lobes emplaced via a continuum of different mechanisms with the principal mechanism being inflation. The dominant structural features observed on these flow fields included: fissures/faults, vents, levees, channels, tubes and pressure ridges. Other structural features present were pahoehoe toes/lobes, breakouts and squeeze‐ups. Slabby pahoehoe resulting from slab‐crusted lava was the transitionary lava type from pahoehoe to aa observed at all the sites. Transition zones correspond to slopes of > 10°. Variations in flow morphology and textures across profiles and downstream were repetitive, suggesting a cyclical nature for the responsible processes. Copyright © 2010 John Wiley & Sons, Ltd.     

北部湾墨西哥湾扇贝形态性状与闭壳肌质量的关系

为寻找墨西哥湾扇贝中对其闭壳肌重量影响最显著的形态学特征,在整个扇贝的生长过程中,每一个月测一次壳高(mm)、壳宽(mm)、铰合线长(mm)、体质量(g)和闭壳肌质量(g),每一轮的样本采集量为60,通过通径分析研究这些形态学特征对闭壳肌质量的影响。结果显示,根据各形态学特征对闭壳肌质量的直接的、间接的、总路径的贡献,发现体质量的影响是最显著的(p<0.01),其他的形态学特征如壳高、壳宽和铰合线长对于闭壳肌生长既不限制也不促进。     

Application of rRNA probes and fluorescence in situ hybridization for rapid detection of the toxic dinoflagellate Alexandrium minutum

The dinoflagellate Alexandrium minutum is often associated with harmful algal blooms (HABs). This species consists of many strains that differ in their ability to produce toxins but have similar morphology, making identification difficult. In this study, species-specific rRNA probes were designed for whole-cell fluorescence in situ hybridization (FISH) to distinguish A. minutum from two phylogenetic clades. We acquired the complete SSU to LSU rDNA sequences (GenBank accession numbers JF906989-JF906999) of 11 Alexandrium strains and used these to design rRNA targeted oligonucleotide probes. Three ribotype-specific probes, M-GC-1, M-PC-2, and M-PC-3, were designed. The former is specific for the GC clade ("Global clade") of A. minutum, the majority of which have been found non-toxic, and the latter two are specific for the PSP (paralytic shellfish poisoning)-producing PC clade ("Pacific clade"). The specificity of these three probes was confirmed by FISH. All cells in observed fields of view were fluorescently labeled when probes and target species were incubated under optimized FISH conditions. However, the accessibility of rRNA molecules in ribosomes varied among the probe binding positions. Thus, there was variation in the distribution of positive signals in labeled cells within nucleolus and cytosol (M-GC-1, M-PC-3), or just nucleolus (M-PC-2). Our results provide a methodological basis for studying the biogeography and population dynamics of A. minutum, and providing an early warning of toxic HABs.