Distribution of dissolved species and suspended particulate copper in an intertidal ecosystem affected by copper mine tailings in Northern Chile

The coastline near Chañaral in Northern Chile is one of the most highly Cu-contaminated zones in the world due to discharges from mining activities for more than 60 years. The speciation of Cu has been studied to determine the importance of organic complexation in highly contaminated areas, and to assess the likely physiological impacts of Cu on marine organisms. Dissolved Cu concentrations of up to 500 nM were measured, completely saturating organic ligands and leading to free Cu²⁺ concentrations in excess of 10^− 8 M. These values are higher than those reported in any other marine environment, and because they occur over an extensive area, provide a unique opportunity to study the effects of Cu on marine ecosystems and to see how Cu behaves when its speciation is predominantly inorganic. We found strong gradients in free Cu²⁺ between Chañaral and adjacent areas with lower Cu, where speciation is dominated by organic complexation. There is also a significant increase in the partitioning of Cu onto suspended particles in the contaminated areas, consistent with previous studies that showed that organic ligands stabilize Cu in the dissolved phase, whilst “excess” Cu is rapidly scavenged. Those high dissolved Cu concentrations persist in spite of solid phase partitioning and advective processes along this open-ocean coastline, suggesting that Cu inputs into the system are still very large. Measurements were made using anodic stripping voltammetry with a thin mercury film coated with Nafion, which previous workers have shown can mitigate ambiguity in the data arising from inadvertent reduction of organic complexes. Our findings suggest that this is a useful methodology for contaminated systems.     

氨基酸在粘土高岭石上吸附等温线的研究

研究了4种氨基酸（甘氨酸，赖氨酸，天冬氨酸，谷氨酸）在粘土高岭石上的吸附等温线以及金属铜离子对其等温线的影响。研究表明，氨基酸在高岭石上的吸附等温线以及金属铜离子存在时的吸附等温线均属Langmuir型等温线；铜离子浓度增加时，其等温线斜率也增加，并认为体系可形成Ⅰ型三元表面络合物，铜离子对氨基酸在高岭石上等温线影响的规律和在相同体系中它对氨基酸在高岭石上交换吸附百分率E（%）-pH曲线的影响规律相一致。     

硫酸皮肤素寡糖的分离与制备

利用软骨素酶 ABC (Chondroitinase ABC,EC4 .2 .2 .4 )对硫酸皮肤素 (Dermatan Sul-fate,DS)进行控制降解。对得到的混合寡糖首先采用低压凝胶渗透色谱 (L PGPC)进行分级 ,然后对每一组分再利用强阴离子交换高压液相色谱 (SAX- HPL C)进行分离 ,最终制备出聚合度为 2 ,4 ,6 ,8,10 ,12的寡糖纯品。寡糖纯度采用 SAX- HPL C,毛细管电泳 (CE)以及聚丙烯酰胺凝胶电泳(PAGE)进行检验 ,结构采用电喷雾离子化质谱 (ESI- MS)以及核磁共振波谱 (NMR)技术确定     

北祁连中段浪力克—牛头山一带地球化学特征

近年来,部署在重要成矿区带的1：5万区域矿产调查在全国陆续展开,这对提高地质矿产研究程度,进一步圈定找矿靶区具有重要意义。其中要求进行1：5万水系沉积物测量、高精度地面磁测、自然重砂测量和遥感异常提取。本文以甘青交界的浪力克一牛头山一带1：5万区域矿产调查中水系沉积物测量实际资料为依据,探讨了浪力克铜矿区及其区域地球化学特征,认为Cu、Pb、Zn、Au、Ag异常分布与含铜火山岩系分布一致,异常规模显示该矿外围仍具有较大的找矿潜力。     

邹平火山岩盆地铜矿地质成因地球物理特征探讨

邹平铜矿处于齐河-广饶深大断裂带南部的邹平火山岩盆地中,形成于破火山口火山通道充填的石英正长闪长岩岩颈中央上部,包括伟晶岩型铜矿和细脉浸染状斑铜矿床两种类型。前者矿体较小,但品位高;后者品位较低,但规模中等。含矿石英正长闪长岩等密度小、磁性弱,故在火山岩系中呈现高背景重力场上的重力低和杂乱高磁场背景中的低负异常,即“重磁同低”,且高极化。重磁同低异常区和高极化率异常带,是本区寻找铜矿的有利部位。     

Effects of enhanced zinc and copper in drinking water on spatial memory and fear conditioning

Ingestion of enhanced zinc can cause memory impairments and copper deficiencies. This study examined the effect of zinc supplementation, with and without copper, on two types of memory. Rats raised pre- and post-natally on 10 mg/kg ZnCO₃ or ZnSO₄ in the drinking water were tested in a fear-conditioning experiment at 11 months of age. Both zinc groups showed a maladaptive retention of fearful memories compared to controls raised on tap water. Rats raised on 10 mg/kg ZnCO₃, 10 mg/kg ZnCO₃ + 0.25 mg/kg CuCl₂, or tap water, were tested for spatial memory ability at 3 months of age. Significant improvements in performance were found in the ZnCO₃ + CuCl₂ group compared to the ZnCO₃ group, suggesting that some of the cognitive deficits associated with zinc supplementation may be remediated by addition of copper.     

Speciation of sulfate components in size-fractionated aerosol particles using sulfur K-edge X-ray absorption near-edge structure （XANES）

Sulfates are a main constituent of aerosols, which sulfate aerosols, it is necessary to determine what can cause various environmental problems sulfate ions are contained in these aerosols In the evaluation of the influence of In this study, sulfur K-edge XANES was used to determine sulfate species present in size-fractionated aerosol particles based on the post-edge structure after the main absorption peak in the XANES region. Aerosol samples were collected as part of the Japan-China joint project, ＂Asian Dust Experiment on Climate Impact＂ using a low-volume Andersen-type air sampler. XANES was measured at Beamline BL-9A at Photon Factory, Japan. A comparison of the XANES spectra of reference sulfate materials and aerosol samples collected in Tsukuba in Japan clearly showed that （NH4）2SO4 was the main sulfur species in particles with a smaller diameter and gypsum was the main sulfur species in particles with a larger diameter. A simulation of the XANES spectra by reference materials allows us to obtain the quantitative mixing ratios of the different sulfate species present in the aerosol samples. The presence of minor sulfur species other than （NH4）2SO4 and gypsum at the surface of mineral aerosols is suggested in our simulations and by a surface-sensitive conversion electron/He-ion yield XANES. In the absence of a contribution from a large dust event, the mole concentration of gypsum in the mineral aerosol fraction determined by XANES is similar to that of Ca which is determined independently using ion chromatography. This shows that the Ca and sulfate in the mineral aerosols are present only as gypsum. Considering that calcite is the main Ca mineral in the original material arising from an arid and semi-arid area in China, it is strongly suggested that gypsum is formed in aerosol during its long-range transportation by a reaction between calcite and sulfate ions.     

湿地生态系统碳循环过程及碳动态模型

从地上、地下有机物质生产对湿地碳输入的贡献,湿地土壤碳库以及土地利用变化对湿地土壤碳库和碳排放的影响,甲烷排放和可溶性有机碳输出以及影响因子,湿地生态系统碳循环动态模型4个方面对湿地生态系统碳循环国内外研究进展和研究成果进行综述、分析,提出了我国亚热带区域天然湿地碳循环研究的主要热点和方向:⑴沿海湿地碳库估算及土地利用转化对土壤碳库和温室气体排放的影响;⑵酸沉降对于我国东南沿海低纬度地区湿地甲烷排放的影响;⑶沿海湿地生态系统碳循环动态模型的应用与开发;⑷湿地系统可溶性有机碳的输出机理探讨.     

Origin of the Nchanga copper–cobalt deposits of the Zambian Copperbelt

The Zambian Copperbelt forms the southeastern part of the 900-km-long Neoproterozoic Lufilian Arc and contains one of the world’s largest accumulations of sediment-hosted stratiform copper mineralization. The Nchanga deposit is one of the most significant ore systems in the Zambian Copperbelt and contains two major economic concentrations of copper and cobalt, hosted within the Lower Roan Group of the Katangan Supergroup. A Lower Orebody (copper only) and Upper Orebody (copper and cobalt) occur towards the top of arkosic units and within the base of overlying shales. The sulfide mineralogy includes pyrite, bornite, chalcopyrite, and chalcocite, although in the Lower Orebody, sulfide phases are partially or completely replaced by malachite and copper oxides. Carrollite is the major cobalt-bearing phase and is restricted to fault-propagation fold zones within a feldspathic arenite. Hydrothermal alteration minerals include dolomite, phlogophite, sericite, rutile, quartz, tourmaline, and chlorite. Quartz veins from the mine sequence show halite-saturated fluid inclusions, ranging from ~31 to 38 wt% equivalent NaCl, with homogenisation temperatures (Th_TOT) ranging between 140 and 180°C. Diagenetic pyrites in the lower orebody show distinct, relatively low δ ³⁴S, ranging from −1 to −17‰ whereas arenite- and shale-hosted copper and cobalt sulfides reveal distinctly different δ ³⁴S from −1 to +12‰ for the Lower Orebody and +5 to +18‰ for the Upper Orebody. There is also a clear distinction between the δ ³⁴S mean of +12.1±3.3‰ (n=65) for the Upper Orebody compared with +5.2±3.6‰ (n=23) for the Lower Orebody. The δ ¹³C of dolomites from units above the Upper Orebody give δ ¹³C values of +1.4 to +2.5‰ consistent with marine carbon. However, dolomite from the shear-zones and the alteration assemblages within the Upper Orebody show more negative δ ¹³C values: −2.9 to −4.0‰ and −5.6 to −8.3‰, respectively. Similarly, shear zone and Upper Orebody dolomites give a δ ¹⁸O of +11.7 to +16.9‰ compared to Lower Roan Dolomites, which show δ ¹⁸O of +22.4 to +23.0‰_. Two distinct structural regimes are recognized in the Nchanga area: a weakly deformed zone consisting of basement and overlying footwall siliciclastics, and a moderate to tightly folded zone of meta-sediments of the Katangan succession. The fold geometry of the Lower Roan package is controlled by internal thrust fault-propagation folds, which detach at the top of the lowermost arkose or within the base of the overlying stratigraphy and show vergence towards the NE. Faulting and folding are considered to be synchronous, as folding predominantly occurred at the tips of propagating thrust faults, with local thrust breakthrough. The data from Nchanga suggests a strong link between ore formation and the development of structures during basin inversion as part of the Lufilian Orogeny. Sulfides tend to be concentrated within arenites or coarser-grained layers within shale units, suggesting that host-rock porosity and possibly permeability played a role in ore formation. However, sulfides are also commonly orientated along, but not deformed by, a tectonic fabric or hosted within small fractures that suggest a significant role for deformation in the development of the mineralization. The ore mineralogy, hydrothermal alteration, and stable isotope data lend support to models consistent with the thermochemical reduction of a sulfate- (and metal) enriched hydrothermal fluid, at the site of mineralization. There is no evidence at Nchanga for a contribution of bacteriogenic sulfide, produced during sedimentation or early diagenesis, to the ores.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.Editorial handling: H. Frimmel     

DMS and SO2 at Baring Head, New Zealand: Implications for the Yield of SO2 from DMS

Atmospheric dimethyl sulfide (DMS) and sulfur dioxide (SO₂) concentrations were measured at Baring Head, New Zealandduring February and March 2000. Anti-correlated DMS and SO₂ diurnalcycles, consistent with the photochemical production of SO₂ from DMS, were observed in clean southerly air off the ocean. The data is used to infer a yield of SO₂ from DMS oxidation. The estimated yields are highly dependent on assumptions about the DMS oxidation rate. Fitting the measured data in a photochemical box model using model-generated OH levels and the Hynes et al. (1986) DMS + OH rate constant suggests that theSO₂ yield is 50–100%, similar to current estimates for the tropical Pacific.However, the observed amplitude of the DMS diurnal cycle suggests that the oxidation rate is higher than that used by the model, and therefore, that theSO₂ yield is lower in the range of 20–40%.