离子交换树脂富集分离、火焰原子吸收光度法测定地质样品微量金

试验了四十多种常见存元及贵金属元素对富集和测定的影响。拟定了一个灵敏、快速、准确、成本低廉的地质样品中微量金的测定方法。结果令人满意，本法适用于一般地质样品中w(Au)/10^-6;0.05-50的测定。     

Systematics of zircon crystallisation in the Cretaceous Separation Point Suite, New Zealand, using U/Pb isotopes, REE and Ti geothermometry

Plutonic zircons from the Cretaceous Separation Point Suite (SPS) were analysed by LA-ICPMS for U–Pb isotope ratios and trace element concentrations. Pooled ²⁰⁶Pb/²³⁸U ages range from 112 to 124 Ma. Cathodoluminescence imaging reveals minor inheritence and textural evidence of repeated dissolution and re-precipitation of zircon. Core and rim spot analyses, however, document zircon growth during extended periods of time (>2 myr). Protracted crystallisation histories for simple plutonic systems are inconsistent with generalised thermal constraints, which predict cooling below the solidus within <1 myr. Consequently, we conclude that the SPS granitoids sampled in this study were not emplaced rapidly but incrementally over extended time periods. Zircon Th/U and Zr/Hf ratios are positively correlated with crystallisation temperatures, consistent with crystallisation from evolving melts. However, highly variable trace element concentrations, along with temperature reversals are indicative of complex crystallisation histories involving continuous fractional crystallisation repeatedly punctuated by hotter, more mafic magma recharge. Normalised abundances of the redox-sensitive elements Eu and Ce in zircon vary systematically with degrees of whole rock differentiation, pointing to evolutionary trends in magmatic oxidation states coupled with feldspar crystallisation.     

Liberation-limited grade/recovery curves from X-ray micro CT analysis of feed material for the evaluation of separation efficiency

Procedures for 3D mineral liberation analysis by X-ray micro CT (XMT) are presented and discussed including the construction of liberation-limited grade/recovery curves for specific feed materials. In this way, actual separation efficiencies can be compared to what might be expected for a perfect separation limited only by the extent of liberation. It is shown that 3D mineral liberation analysis based on XMT is preferred to 2D section analysis which overestimates the extent of liberation. By way of example, procedures and experimental results are presented and discussed for feed material in the case of phosphate rock flotation.     

一次大磁暴主相期间ENA氧与氢的分离及分布特征——TWINS卫星观测

本文采用基于ENA（Energetic Neutral Atoms）次生电子起始脉冲高度分布,统计拟合分离中能段ENA两种主要成分氢和氧的方法,研发了实现ENA氢与氧分离的TWINS卫星原始数据处理软件;其中所需要的脉高分布模型,参照已有理论公式,利用TWINS（Two Wide-angle Imaging Neutral-atom Spectrometers）卫星标定数据进行拟合确定未知参数,再加以计算得到.将上述方法用于TWINS卫星实测数据,分离得到一次大磁暴主相期间ENA-H和ENA-O微分通量随观测视线的分布及其随主相增长的变化.分析发现：（1）ENA-H与ENA-O微分通量的强度和随观测视线的分布特征都有明显差别,从某种角度反映出ENA之源的O⁺与H⁺离子强度和分布之间的差异;（2）接近主相极大时,ENA-H有很强的低高度发射（LAE,Low Altitude Emission）,出现在磁地方时午夜前极光和亚极光纬度区,意味着该区域较强的等离子片和环电流质子沉降,进入到外层基底以下较低高度大气层;而ENA-O则未有明显LAE产生;ENA-O强通量观测视线主要穿过广大环电流区,磁地方时主要在午夜之后以及黄昏前和黎明前后;（3）在磁暴主相快速增长期,ENA-O平均总通量持续增大,而ENA-H同步减小,ENA-O与ENA-H平均总通量的比率随环电流指数Dst绝对值的增大而大致成正比增长.

     

金属硫化物Re-Os同位素定年技术进展

近30年来,Re-Os同位素分析方法在样品溶解、化学分离及质谱测定,以及微区分析等方面取得了重要进展,Re-Os同位素体系已成为同位素地质年代学研究的一个重要手段。本文对近年来金属硫化物Re-Os同位素分析技术的研究发展现状以及存在的问题进行系统评述,包括野外工作和室内金属硫化物矿物精确识别和挑选、样品的分解、分离富集技术到仪器测定、参考标样选择等,并对化学处理过程中如何提高试剂纯度,避免器皿、试剂和环境污染,如何降低实验流程空白等方面给出了建议,可为相关研究者优化Re、Os及其同位素的高精度测试提供参考。

     

反演磁性地层界面的逐步剥离磁场法

在对前人研究方法总结对比的基础上,本文提出了一种逐步剥离位场反演磁性地层界面的方法,该方法假定位场是由一个等效单位厚度层的等效磁化强度变化引起,通过逐步剥离位场,得到等效单位厚度层的等效磁化强度,进而求取磁性地层的起伏.本文进行了理论模型计算和野外实例处理,取得了良好效果.     

Quantitative Separation of As(III) and As(V) from a Synthetic Water Solution Using Ion Exchange Columns in the Presence of Fe and Mn Ions

The quantitative separation of As(III) from a water sample containing As(III) and As(V) in the presence of Fe and Mn in an ion exchange resin (AG1 X8) column for the speciation of arsenic is described. Individual and combined effects of Fe and Mn on the separation of As(III) from the solution have been studied separately. In absence of Fe and Mn, the ratio between the As(T) concentration in the eluent and the As(III) concentration in the original sample has been found to be 0.9717 under optimum process conditions. The presence of Fe(II) in the water sample increased the As(T) concentration in the eluent whereas Mn(II) decreased it. Combined effects of Fe and Mn on the percentage increment in the eluent arsenic concentration have been expressed by additive and interactive models. The interactive model has been developed by a statistical software with a 95 % confidence level. In most of the cases the error on the determination of the As(III) concentration had a minimum when using the interactive model.     

Flow around a partly buried cylinder in a steady current

The flow around a cylinder, surface mounted or partly buried has been examined at Reynolds number of 1.3×10⁴ and 2.6×10⁴ by using the flow visualization method in the case of steady current. The lengths of the upstream and downstream separation regions were determined and the characteristics of the flow area were discussed for the cylinder having different burial depth to the diameter ratio (G/D). For comparsion, some numerical results obtained from the application of the FLUENT, computational fluid dynamics (CFD) software package have also been presented. Both experimental and numerical results indicated that the lengths of the separation regions near the upstream and downstream of the cylinder decreased with the increasing burial ratio (G/D=0, 0.20, 0.50). The results have significant implications both for the illustration of the potential for using CFD software and highlighting the need for data of two dimensional flow around the buried cylinder.     

A new method for separation of 2D incident and reflected waves by the Morlet wavelet transform

A new method based on the Morlet wavelet transform for separating a 2D wave field into incident and reflected waves is proposed in this paper. The principle of this method, first, is derived for constant depths. Then, using the linear shoaling theory, the method is extended to an arbitrary sloping bathymetry. Owing to the time-frequency characteristic of wavelet transform, the present method can separate waves in the real time domain and is not confined by the stationary assumption of waves. The efficiency and accuracy of this method are demonstrated using numerical simulated data.     

三元体系CaCl2-SrCl2-H2O相平衡在高钙锶比卤水体系中分离提取氯化锶的应用

采用等温溶解平衡法测定了三元体系CaCl₂-SrCl₂-H₂O温度在353.15 K时共饱和点的溶解度。基于实验结果和文献已有报道的该体系多温下的相平衡数据,模拟了南翼山油田卤水中氯化钙和氯化锶在温度323.15 K下的分离实验。模拟钙锶分离实验结果表明,物质的量比为25.41∶1的CaCl₂和SrCl₂的混合溶液在323.15 K下蒸发结晶提纯后的固相中钙锶物质的量比降低为1.73∶1,SrCl₂的回收率为52.47%,将所得一次固相产品在323.15 K下溶解并再次蒸发后,钙和锶的物质的量比从1.73∶1降至1.1∶1,SrCl₂的回收率为78.67%,SrCl₂的总回收率为41.28%。