Calcium,Na, K and Mg Concentrations in Seawater by Inductively Coupled Plasma‐Atomic Emission Spectrometry: Applications to IAPSO Seawater Reference Material,Hydrothermal Fluids and Synthetic Seawater Solutions

We report a measurement procedure to determine simultaneously the major cation concentrations (Na, Ca, K and Mg) of seawater‐derived solutions by inductively coupled plasma‐atomic emission spectrometry. The best results were obtained when the IAPSO (‘standard’) seawater reference material was diluted by thirty times with Milli‐Q^® water. We obtained an average reference value r_K (the ratio of the mass fraction of potassium to that of chlorine, i.e., (g kg^?1)/(g kg^?1)) for IAPSO seawater of 0.0205 ± 0.0006 (2.9% RSD), not significantly different from 0.0206 ± 0.0005 (2.4% RSD) for seawater composition reported in the literature. The measured Na, Ca and Mg concentrations correspond to r_Na, r_Ca and r_Mg values of 0.5406 ± 0.0026 (0.5% RSD), 0.02192 ± 0.00048 (2.2% RSD) and 0.06830 ± 0.00047 (0.7% RSD), respectively, in line with previous values measured by wet‐chemistry and atomic absorption spectrophotometry or wet‐chemical titration. Our measurement procedure was used successfully on synthetic seawater solutions and high‐temperature hydrothermal fluids.     

以地理国情监测为契机改造地理科学专业——以滁州学院为例

在当前社会经济发展形势下,传统地理科学专业人才培养模式存在着诸多不足,实践能力弱、就业范围窄、学无所用等。结合当前学科发展趋势,对传统地理科学专业进行改造,以滁州学院为例,在充分分析总结地科专业发展现状的基础上,阐述了该专业应紧紧抓住地理国情监测这一契机确定专业改革方向,并对改革的可行性与发展目标进行了详细论述和讨论,认为以地理国情监测为契机改造地理科学专业是可行的。可为地方院校地理科学专业向地理国情监测方向转型提供参考。     

大行星运动对太阳黑子活动的可能影响

本文计算了由太阳系大行星轨道运动引起的日心相对于太阳系质心的轨道运动角动量变化率j_⊙,在理论上对j_⊙作展开,表明它存在多项短周期变化,与太阳黑子资料的分析结果相比较,两者结果是符合的,它们具有一致的谱结构。因此,行星的轨道运动对太阳黑子活动存在动力作用的可能性又进一步得到了验证。     

Geochemical and isotopic evidence of a groundwater source in the Corral Canyon meadow complex,central Nevada,USA

Major inorganic ions and stable carbon and oxygen isotopes in stream water, groundwater, groundwater seeps and springs were measured in the Corral Canyon meadow complex and watershed in the Toquima Mountains of central Nevada, USA. The purpose of the study was to determine whether stream water or groundwater was the source of water that supports vegetation in the meadow complex. Water samples from the watershed and meadow complex were mixed cation–HCO₃ type. Stream water sampled at different locations in the meadow complex showed variations in temperature, pH and specific conductance. The cation–anion proportions for stream water were similar to groundwater, groundwater seeps and runoff from the meadow complex. Stable oxygen isotope ratios for stream water (?17·1 to ?17·6‰ versus VSMOW) and groundwater and groundwater seeps in the meadow site (?17·0 to ?17·7‰ versus VSMOW) were similar, and consistent with a local meteoric origin. Dissolved inorganic carbon (DIC) and the δ ¹³C_DIC for stream water (?12·1 to ?15·0‰ versus VPDB) were different from that of groundwater from the meadow complex (?15·3 to ?19·9‰ versus VPDB), suggesting different carbon evolution pathways. However, a simple model based on cation–δ ¹³C_DIC suggests that stream water was being recharged by shallow groundwater, groundwater seeps and runoff from the meadow complex. This leads to the conclusion that the source of water that supports vegetation in the meadow complex was primarily groundwater. The results of this study suggest that multiple chemical and stable carbon isotope tracers are useful in determining the source of water that supports vegetation in meadow complexes in small alpine watersheds. Copyright © 2004 John Wiley & Sons, Ltd.     

Spectrum characteristics of major ion concentrations at Wuhan sectoin of the Changjiang Rriver

Spectrum analyses of water quality time series have been carried out for five hydrometric stations including Wuhan hydrometric station of the Changjiang(Yangtze) River, etc. The fluctuations of Ca²⁺, Mg²⁺ and HCO ₃ ⁻ concentrations in river water under different physical geography conditions have about two-year cycle which is corresponding to hydrometeorological quasi-biannual-oscillation (QBO). Na⁺, Cl⁻ SO ₄ ²⁻ have about two-year cycle in the area lightly affected by human activities while two-year cycle doesn’t exist in the area heavily affected by human activities. All the fluctuations of major ions have about three-month cycle. The river diseharge fluctuation accounts for 43.9%, 45.1%, 54.3%, 33.9%, 30.3% and 42.7% of the variance of Ca²⁺, Mg²⁺, HCO ₃ ⁻ , Na⁺, Cl⁻, SO ₄ ²⁻ , respectively, at Wuhan from 1962 to 1985. According to the spectrum characteristic of major ions, the duration of the time series has to be at least 13 years for trend analysis of monthly water quality data. Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 49671017). Biography: XIA Xing-hui(1971-), female, a native of Hunan Province, Ph. D. Her research interest includes environmental chemistry.     

用区域重力资料确定的华北地台南缘地缝合线及其地质意义

利用１∶２０万区域重力资料，结合航磁，电磁测深、遥感、天然地震等丰富的地质、地球物理资料，根据断裂的地质、地球物理标志，在华北地台南缘发现并确定了控制火山喷发的裂隙—中心式古火山通道，即隐伏的北西西向的上戈—铁炉坪—付店超壳断裂带。该断裂属华北地台南缘不同时代、不同性质的近东西向的地缝合线。研究认为：该断裂及其次级断裂不仅是重要的长期多次活动的控岩、导矿和容矿构造，而且也为矿床的多次改造、叠加和再富集提供了热源。它的发现，对重新认识豫西地区大地构造的演化特征，建立新的成矿模式，拓宽该区的找矿前景具有重要意义。     

Temporal variability of selected dissolved elements in the lower Orinoco River,Venezuela

Monthly analyses of pH, conductance, alkalinity, total suspended solids, dissolved major cations (Na, K, Ca and Mg), and selected dissolved trace elements (Fe, Al, Mn, Cu, Zn and Cr) were conducted on waters of the lower Orinoco River from February 2004 to May 2006. The data show strong seasonal variability. Major cations had maximum concentrations at low water, and were correlated with pH, conductance and alkalinity because of the tributaries coming from the Andean zones, where the weathering of evaporites and carbonate shales controls water chemistry. K concentrations did not show any relation with evaporite weathering, probably because large amounts of K come from the Guayana Shield rivers as a consequence of feldspar weathering. The concentrations of dissolved Fe, Mn and Cu were highest during the high water stage. Concentrations of the elements K, Cr, Zn and Cu are correlated with each other but not with dissolved Fe and Al, which probably are complexed with humic and fulvic substances. Mn concentrations did not show relationships with other variables. Inter‐annual variability of dissolved elements is explained by temporal changes in precipitation. Copyright © 2008 John Wiley & Sons, Ltd.     

电感耦合等离子体发射光谱法测定铅锌矿中15个主次量元素

铅锌矿多元素同时测定中,样品预处理过程受多种不同因素的影响,单因素试验往往无法同时为多因素实验提供合理的优化方案。本文采用盐酸-硝酸溶矿,考察了样品预处理过程中混合酸配比、混合酸体积、消解时间及消解温度对消解效果的影响,利用正交试验设计及极差分析确定了最优消解条件:盐酸-硝酸混合酸配比3∶1,混合酸体积10 m L,消解时间120 min,消解温度90℃,用电感耦合等离子体发射光谱法同时测定铅锌矿中15个主次量元素(铅锌铜锰砷银铋镉钴镍镓铟钼锗锑)的含量。在最优条件下,用富铅锌矿石国家标准物质(GBW 07165)进行试验,大多数元素的精密度(RSD,n=12)和准确度小于5%,方法检出限为0.0019~0.048μg/g。基于铅锌矿主要是以硫化物形式存在,采用一系列硫化物国家标准物质验证方法的准确度及可行性,检测结果基本都在标准值的误差范围内。应用该方法分析湖南某矿区中大批量铅锌矿样品,标样质量统计合格率为100%,密码质量统计合格率大于97%。     

电感耦合等离子体发射光谱法测定硼硅酸盐玻璃中的硼等常见元素

硼硅酸盐玻璃中的硼、钙、镁、铝、铁、钛、硅等常见元素普遍采用各元素分别测定的方式进行分析,分析效率很低;而且硼的测定普遍采用容量法,当B2O3含量低于1%时,容量法测定误差较大。本文以KOH熔融的方式消解样品,采用电感耦合等离子体发射光谱法(ICP-AES)进行分析。通过实验研究了KOH用量和不同称样量对B2O3测定结果的影响。结果表明,KOH用量在3 g以上时有较好的熔样效率和熔样效果,称样量低于0.4 g对B2O3测定结果无明显影响,考虑到其他元素的测定,确定了KOH用量优选3 g,称样量优选0.1 g。在此条件下,测定B2O3等常见元素的精密度(RSD,n=6)≤2%,加标回收率在96.0%~105.6%之间,除Si O2测定误差较大外,其他元素的测定结果均令人满意。本方法确定的B2O3的定量限为0.067%,且对于B2O3最高含量达到16%的测定结果也令人满意,因此可测定B2O3含量的范围至少为0.067%~16%。当样品中的B2O3含量高于4%时,方法准确度和精密度与国家标准分析方法(容量法)相当;当B2O3含量低于1%时,方法准确度和精密度都优于容量法。与现有报道相比,本方法显著拓宽了B2O3的测定范围,并具有良好的准确度,而且在B2O3准确测定的同时,也实现了Ca、Mg、Al、Fe、Ti的定量分析和Si的半定量分析,大大提高了分析效率,可以实现硼硅酸盐玻璃中B2O3等常见元素的准确快速分析。     

甘肃滴水山金矿不同构造岩相带岩石地球化学特征及构造控矿机理探讨

滴水山金矿床位于北祁连加里东褶皱带的西段,分布于北西西向剪切带内,通过野外实地观察和镜下鉴定、样品测试,对该剪切带内Au2矿体构造-岩相特征及其地球化学元素变化特征进行了研究,结果表明：①该剪切带存在2期变形,早期为由北向南斜冲的韧-脆性剪切变形,晚期为斜向下滑的脆性变形。②根据元素分析结果,Au元素含量从安山质晶屑凝灰岩带→糜棱岩化安山质晶屑凝灰岩带→蚀变碎裂岩带→金矿化蚀变碎裂岩带逐步增高。根据相关性分析,Au与Ag相关性最好,其次为Pb、Mo,与As、Hg相关性一般。研究认为,滴水山金矿床北西西向剪切带早期韧-脆性变形有利于成矿元素的活化迁移,为Au元素的运移和初步富集提供了通道,晚期脆性变形主要形成各种张裂隙和构造破碎带,由于构造体制发生转换,导致Au元素的再次富集形成金矿体。