743阳离子交换快速分离——ICPS-PGS2单道扫描直读光谱仪测定地质样品中15个微量稀土元素

本文采用过氧化钠(Na_2O_2)熔样,743阳离子交换树脂快速分离,0.4mol/L柠檬酸25ml洗脱稀土,无需浓缩,即可用lCPS-PGS2单道扫描直读光谱仪直接测定15个微量稀土元素。在选择的最佳测量条件下,本法测定下限为0.005~g/ml(Eu)-0.50μg/ml(Ce),标准加入回收在88％—110％之间,样品分析精度为3.3％—17％,样品分析结果与参考值相符。本法适用于一般地质样品中微量稀土元素的例行分析。     

南极与青藏高原冰芯中阳离子对比研究

本文选取南极Ｎｅｌｓｏｎ站、横断山的海螺沟冰川、喜马拉雅山的达索普冰川、西昆仑的古里雅冰川和天山的托木峰冰川为研究对象,以化学成分作为指标,作了模糊聚类分析。结果表明,在不同水平下分类,冰川之间关系程度不同,反应的气候环境也不同。南极与青藏高原冰川中离子浓度存在差异,尤其是Ｎａ＋和Ｃａ２＋的含量差异显著。Ｎｅｌｓｏｎ站的Ｃａ２＋／Ｎａ＋之值比青藏高原各冰芯低许多,其与海水中Ｃａ２＋／Ｎａ＋之值相当。Ｃａ２＋／Ｎａ＋之值体现了冰川离海洋的距离,Ｃａ２＋／Ｎａ＋之值越小,则冰川离海洋越近,反之则越大。     

苏锡常地区浅层地下水rNa/rCl特征及其成因初探

本文从苏锡常地区浅层地下水含水介质及包气带沉积环境的角度,阐明了浅层地下水中Cl-和Na 浓度东高西低的分布特征。根据数据分析,浅层地下水中Na 与Cl-的毫克当量比值rNa/rCl与海侵形成的沉积环境和沉积历史关系密切。地下水淡化历史越长,含水层介质中吸附的Na 与地下水中的Ca2 和Mg2 之间的阳离子交换吸附程度越高,大量的Na 进入地下水中,使得rNa/rCl比值越高。     

Influence of Salinity on pH and Aluminum Concentration on the Interaction of Acidic Red Soil with Seawater

Contamination of acidic red soil in the coastal areas of Okinawa Islands is a serious environmental problem. This study was conducted to examine the effects of the salinity on pH and aluminum concentration when the acidic red soil interacts with seawater. Acidic red soil from Gushikawa recreation center was fractionated into bulk soil, coarse sand and silt + clay. Different weights of each fraction were equilibrated with seawater solutions. The pH and concentrations of Al³⁺, Na⁺, K⁺, Ca²⁺ and Mg²⁺ were then analyzed in the extracts. The results showed a decreasing trend of pH with increasing soil to solution ratio while the extracted Al³⁺ revealed an increasing trend. The lowest pH values were 3.85, 4.06, 4.41, 4.66 and their corresponding highest Al³⁺ concentrations were 2.50, 1.01, 0.062 and 0.036 mmolL⁻¹ in the seawater extracts, one-tenth seawater extracts, one-hundredth seawater extracts and one-thousandth seawater solution extracts, respectively. Mostly, the concentrations of Na⁺, Ca²⁺, Mg²⁺ and especially K⁺ decreased with increasing soil weight in the high salinities but showed the opposite trend in the low salinity samples. Potassium concentration decreased by 39%, 53% and 40% in the seawater extracts, one-tenth and one-hundredth seawater extracts but increased by 200% in one-thousandth seawater extracts. The coincidence of the increase in Al³⁺ and H⁺ concentrations, and the decrease of Na⁺, K⁺, Ca²⁺ and Mg²⁺ concentrations in the solutions suggests ion exchange/adsorption, while the increased patterns, particularly at low salinity could be attributed to the dissolution of the species from the soils.     

有机质对S1nm锰矿相金属阳离子交换能力的影响

大洋多金属结核问题长期以来一直受到人们的关注[1～3].大量的研究结果表明,多金属结核中最有经济价值的铜、钴、镍等有价金属元素,主要赋存于仅占整个结核约15%锰矿相中.我们曾对人工合成1 nm锰矿相(synthetic 1nm manganate,以下简称S1nm锰矿相)金属阳离子交换能力作过初步探讨[4,5],研究表明,Cu2+,Co2+,Ni2+,Zn2+等与S1nm锰矿相具有强烈的阳离子交换能力,证明了多金属结核成矿后期的离子交换是铜、钴、镍、锌等有价金属元素进入多金属结核的重要途径之一.     

离子色谱法同时测定铀矿浸出液中的阳离子

对铬铁矿中亚铁的测定方法进行了探讨。首先对已有方法进行了验证和筛选,然后对Li2SO4助熔剂的助溶作用及其反应机理进行了研究,从而推荐了H2SO4-H3PO4-V2O5-V(Ⅳ)-Li2SO4和H2SO4-H3PO4-Ce(SO4)2-Li2SO4两种改进型的溶剂体系用于铬铁矿试样中亚铁的测定,所得结果具有良好的重现性。     

Effects of cation disordering in a natural MgAl2O4 spinel observed by rectangular parallelepiped ultrasonic resonance and Raman measurements

At moderate temperatures, the elastic properties of natural MgAl₂O₄ spinel differ in several significant ways from properties of synthetic spinels. Below 1000 K, the ultrasonic resonant frequencies of an ordered natural spinel change significantly after heat treatment; at higher temperatures, both types of spinels have similar resonant responses. The temperature derivatives of the elastic constants of an ordered spinel also differ from those of disordered spinels at moderate temperatures; again, at higher temperatures, both types of spinels have similar behaviors. The Raman spectra also differ below 1000 K for ordered natural and disordered spinels and are similar at higher temperatures and after cooling to ambient temperature. We associate these changes in ultrasonic resonance and Raman spectra of spinel with cation disordering at high temperature which may be quenched by cooling. We deduce estimates of the inversion parameter from the relative intensities of the two A_1g Raman modes in very good agreement with estimates made from other measurements. We find thatC ₁₁ andC ₁₂ decrease by 4 and 8%, respectively, with 20% inversion in spinel;C ₄₄ is less sensitive to cation order. These results imply that previous measurements of the adiabatic elastic constants of spinels at ambient conditions have been affected by the state of cation disorder of the specimen.     

Seawater Intrusion in the Longkou-Laizhou Area, Shandong

The extensive intrusion (covering an area of 83.7-238.3 km~2 and accounting for 18.6-31.5% of the total area of the plain), the presence of a transitional zone 1.5-6.0 km in width, and the interconnection in distribution between the seawater intrusion district and the region lower than the sea level caused by the strong drop of the groundwater level are major characteristics of the seawater intrusion in the study area. Cation exchange played an important role during the formation of chemical composition of the groundwater in the seawater intrusion district.     

Processes of silicate karstification associated with pan formation in the Darwin–Koolpinya area of northern Australia

Lyons Lagoon, one of many small pans near Darwin, Northern Australia, occurs in lateritized terrain. Formation by structurally facilitated silicate karsti?cation of the parent Cretaceous sandy sediments was earlier proposed. This paper presents the results of thin section microscopy and scanning electron microscopy with energy‐dispersive X‐ray study of pan sediments with a view to assessing the extent to which they re?ect the geomorphological/hydrogeological history. Severe corrosion was found to overprint the impact features of the primary sands, attributed to aggressive leaching and consistent with formation of the depression by karsti?cation when the water table was low. Formation of a smectitic matrix is considered to have followed when the water table was high. Upon subsequent lowering of the water level leaching was resumed, altering smectite to kaolinite and resulting in incongruent dissolution of kaolinite to leave a siliceous residuum. At least two cycles of high followed by low water levels are recognized. Such periodic changes of levels are considered essential to pan formation within freely draining lateritic terrain. The processes of pan formation and alteration of pan sediments (essentially residual deposits) is ongoing, biocorrosion being implicated as an important mechanism. Incongruent kaolinite dissolution, to leave a silica residuum, a hitherto apparently unrecognized process, raises the possibility that silcrete may form as a relative accumulation which is synchronous with lateritic leaching in more elevated topographic positions. Copyright © 2004 John Wiley & Sons, Ltd.     

堆肥对土壤阳离子型微量元素可溶性的影响

本文的主要目的是探讨堆肥对砂壤土阳离子型微量元素-Fe,Mn,Zn,Cu可溶性的影响．通过试验并进行堆肥比例和时间因素的双因子统计分析得出Fe的可溶性随时间的延长而增加,可溶Zn和Mn由于堆肥的加入而减少,可溶Cu极低,实际不受堆肥施入的影响．