Water soluble components of PM_(10) in Chongqing, China

1Introduction Particleswithanaerodynamicdiameterof< 10μmarerecognizedasinhalabaleparticlesandhave beenfoundtobewidelyassociatedwithhealthprob lems(Chapmanetal.,1997).Theywouldalsoinflu enceclimateandvisibilitythroughanumberofimpor tantatmosphericprocesses(Horvath,1993). Rapiddevelopmentofurbanconstructionandrap idgrowthofpopulationhaveexacerbatedChongqing’s pollution.Althoughsulfurdioxidehasbeenreducedby morethan60%incontrasttothevaluein1991,the concentrationsofparticulatematterarestil…     

Metal ions bound to colloids from database to field systems

Nowadays, environmental problems related to soil pollution with heavy metals are numerous, therefore, it is important to understand metal behavior in aquatic sediments and soils and to appreciate their transfer. The fate of the metals in the environment is closely related to their interactions with the major reactive compartments （organic matter, iron and manganese oxides, clays）. The objective of this work is to develop an approach based on the combination of several models to study metal ion speciation in different environmental systems. Models used to describe the interactions of metals with the main reactive phases in the soil are CD-MUSIC （amorphous and crystallized iron oxides）, NICA-Donnan （organic matter and manganese oxides）, and cationic ion exchange model （clays）. Firstly, this work implies the definition of generic parameters to describe the interactions of the studied metals with iron and manganese oxides, a part of this information is missing in the literature. Then, after the validation of the approach by comparison with analytical results, this multi-surface model is applied to test sites corresponding to a soil and to two riverine environments. These new models give good predictions of the behavior of major and trace metal ions even in heterogeneous system characteristics of the natural environment. The measured free metal concentrations in the solution are in agreement with those obtained from model calculations.     

离子色谱法测定高纯镁砂中痕量无机阴离子

采用阴离子交换色谱电导检测法分析高纯镁砂（MgO）中的无机阴离子。MgO粉末在管式电炉1250-1350℃高温下通氧气加热，硫酸盐和氯化物等受热分解，气态生成物被40mL含25mg镁粉的0．25mol／LNaOH溶液吸收。方法的回收率为93．7％-95．3％，精密度（RSD，n=5）为4．32％-4．63％。对若干相关的分析技术问题，亦进行了讨论。     

关于矿床学创新问题的探讨

2003年1月4日至2月15日期间,在5种不同情况下对南极海冰进行了调查研究。包括:(1)基于走航观测的威德尔海至普利茨湾之间海冰分布研究;(2)基于航空拍摄的普利茨湾海冰分布研究;(3)纳拉海峡固定冰和上浮雪厚度钻孔测量以及冰心钻取;(4)中山站附近融化冰的分布研究以及(5)中山站附近海冰早期冻结过程观测研究。结果表明,威德尔海至普利茨湾之间走航观测得到的海冰全部密集度为14.4%,大部分冰(99.7%~99.8%)属于一年冰,观测到冰的厚度在15~150 cm。沿观测航线上海冰最大密集度(80%)出现在威德尔海,从59°56 S到69°22 S以及从040°41 W到076°23 E的区域分布着广阔的水域。这一结果验证了Silvia的海冰漂移理论。普利茨湾沿岸海冰受制于沿岸地形、拉斯曼丘陵以及搁浅冰山的影响,其密集度呈现较大的空间变化。钻孔测量显示,纳拉海峡固定冰平均厚度为169.5 cm。风吹雪的重分布以及日照强度差异是导致纳拉海峡固定冰厚度差异的主要因素。观测表明,中山站附近海冰早期冻结遵循Lange的海冰早期冻结过程“饼状循环”最初的两个阶段。     

Determination of carbon fractionation factor between aqueous carbonate and CO2(g) in two-direction isotope equilibration

The experiments were conducted in the open CO₂ system to find out the equilibrium fractionation between the carbonate ion and CO₂(g). The existence of isotopic equilibrium was checked using the two-direction approach by passing the CO₂−N₂ gases with different δ¹³C compositions (− 1.5‰ and − 23‰) through the carbonate solution with δ¹³C = − 4.2‰. The Δ_{CO3T²⁻−CO2(g)} equilibrium fractionation is given as 6.03 ± 0.17‰ at 25 °C. Discussion is provided about the significance of carbonate complexing in determination of Δ_{CO3T²⁻−CO2(g)} and Δ_{HCO3T⁻−CO2(g)} fractionations. Finally, an isotope numerical model of flow and kinetics of hydration and dehydroxylation is built to predict the isotopic behaviour of the system with time.     

Depression mechanisms of sodium bisulphite in the xanthate-induced flotation of copper activated sphalerite

The effect of sodium bisulphite on the xanthate-induced flotation of copper-activated sphalerite has been studied using batch flotation testing, surface analysis techniques (XPS and ToF-SIMS), and FTIR. The various techniques have been used to identify the mechanisms of interaction of sulphite ions with both collector and the sphalerite surface. The results indicate that sodium bisulphite depressed the flotation of sphalerite particles pre-treated with copper and xanthate at pH 9 with nitrogen and air purging. It was found that sodium bisulphite interacts with the sphalerite surface, as well as with xanthate in its adsorbed state. Based on the evidence obtained in the present study, and in conjunction with previous work, the mechanisms involved in the depression of the xanthate-induced flotation of copper-activated sphalerite by sulphite are proposed. It is suggested that copper xanthate decomposition on the surface of the activated sphalerite and the decomposition of the hydrophobic copper-sulphide-like species on the sphalerite surface are the active mechanisms for sphalerite depression by sodium bisulphite.     

Glaciochemical records from Naimona’Nyi ice core in the Himalayas

A 6-m ice core was recovered in 2004 from the Naimona’Nyi Glacier, the middle Himalayas. Empirical orthogonal function (EOF) analysis on the major ion reveals that EOF1 represents the variations of majority of ions which may be originated from crustal aerosols. Comparing the calcium concentrations from the Naimona’Nyi with these from Dasuopu, East Rongbuk and Guliya ice cores, it is observed that calcium, a good indicator of the input of crustal aerosol in snow, concentrates mostly in the Guliya ice core located on the northern Tibetan Plateau, and gradually decreases from west to east in the Himalayas.     

REE Mineralization of Weathered Crust and Clay Sediment on Granitic Rocks in the Sanyo Belt,SW Japan and the Southern Jiangxi Province,China

Rare earth element (REE) geochemistry and mineralogy have been studied in the weathered crusts derived from the Early Yanshanian (Jurassic) biotite granites of Dabu and Dingnan, as well as in the Indosinian (Permian) muscovite–biotite granite of Aigao in southern Jiangxi province, China, and the weathered crusts and clay sediments on biotite granites in the Sanyo belt, SW Japan, that is, Okayama, Tanakami, and Naegi areas. In all of the weathered crusts, biotite and plagioclase commonly tend to decrease toward the upper part of the profile, whereas kaolinite and residual quartz and K‐feldspar increase. The weathered crusts of the Dingnan granites and some Naegi granites, which are characterized by the enrichment in light REE (LREE) in C horizons, have higher total REE (ΣREE) content than the parent REE‐enriched granites. Weathering of LREE‐bearing apatite and fluorocarbonates in the Dingnan granites and allanite and apatite in some Naegi granites may account for the leaching of LREE at the B horizons. The leached LREE must result in subsequent enrichment of LREE in the C horizons. The enrichment is probably associated with mainly adsorption onto kaolinite and partly formation of possible secondary LREE‐bearing minerals. In Japan it was found that REE mineralization occurs not in the weathered granitic crusts but in reworked clay sediments, especially kaolinite‐rich layers, derived mainly from the weathering materials of REE‐enriched granitic rocks. The clay sediments are more enriched in LREE, which likely adsorbed onto kaolinite. Concentration of heavy REE within almost all the weathered crusts and clay sediments, however, may reflect mainly residual REE‐bearing minerals such as zircon, which originated in the parent granitic rocks. The findings of the present study support the three processes for fractionation of the REE during weathering: (i) selective leaching of rocks containing both stable and unstable REE‐bearing minerals; (ii) adsorption onto clay minerals; and (iii) presence of possible secondary LREE‐bearing minerals.     

Observations of the electric fields that accelerate auroral particles

Electric fields accelerate electrons and ions in the auroral zone at altitudes below 8000 km to produce several distinctive particle distributions. The electric field of electrostatic shocks and double layers produces the inverted-V precipitating electron and up-flowing ion beams. Electrostatic ion cyclotron waves heat ion beams. The electric field in low frequency plasma waves and electrostatic shocks produces ion conics and field-aligned or counterstreaming electrons. Relationships between electric fields and particle distributions are illustrated with data from the S3-3 satellite.     

Terpenoid biomarker distributions in low maturity crude oils

Twenty-seven heavy crude oils of diverse origin were geochemically assessed with respect to both bulk and mlecular composition for the purpose of identifying and quanttfying valid biomarker parameters for low maturity oils. The low thermal maturity level of many of these oils is evident from the bulk and alipathic chromatographic data, and oil sourced from both marine and terrigenous organic matter are represented. Selective metastable ion monitoring (SMIM) was employed to measure separately the distribution of C₂₇, C₂₈, and C₂₉ sterane isomers. The useful maturity indicators include the C₂₉ 5α(H) 20S/20R ratio, the relative quantity of the biological sterane configuration in each of the total normal C₂₇, C₂₈, and C₂₉ steranes, and the rearranged to normal sterane ratio. In addition, C₂₇ rearranged steran es appear to form at a faster rate than C₂₈ or C₂₉ rearranged steranes. However, the isomerization of the C₂₇ biological component appears to occur at a slower rate than the C₂₉ counterpart suggesting that the former may be used as a maturity parameter at higher levels of thermal maturation. In the triterpane distributions, the C₂₇ trisnorhopane isomers and the moretane to hopane ratios appear to be both source and maturity related and cannot be used as successful maturity parameters in oils unless they share a common source. The C₃₁₊ hopane 22S/22R equilibrium ratio appears to increase with increasing molecular weight (C₃₁–C₃₄).