Chemical and Isotopic Composition of Waters and Dissolved Gases in Some Thermal Springs of Sicily and Adjacent Volcanic Islands, Italy

Hydrochemical (major and some minor constituents), stable isotope ( and , δ13C_TDIC total dissolved inorganic carbon) and dissolved gas composition have been determined on 33 thermal discharges located throughout Sicily (Italy) and its adjacent islands. On the basis of major ion contents, four main water types have been distinguished: (1) a Na-Cl type; (2) a Ca-Mg > Na-SO₄-Cl type; (3) a Ca-Mg-HCO₃ type and (4) a Na-HCO₃ type water. Most waters are meteoric in origin or resulting from mixing between meteoric water and heavy-isotope end members. In some samples, δ¹⁸O values reflect the effects of equilibrium processes between thermal waters and rocks (positive ¹⁸O-shift) or thermal waters and CO₂ (negative ¹⁸O-shift). Dissolved gas composition indicates the occurrence of gas/water interaction processes in thermal aquifers. N₂/O₂ ratios higher than air-saturated water (ASW), suggest the presence of geochemical processes responsible for dissolved oxygen consumption. High CO₂ contents (more than 3000 cc/litre STP) dissolved in the thermal waters indicate the presence of an external source of carbon dioxide-rich gas. TDIC content and δ¹³C_TDIC show very large ranges from 4.6 to 145.3 mmol/Kg and from –10.0‰ and 2.8‰, respectively. Calculated values indicate the significant contribution from a deep source of carbon dioxide inorganic in origin. Interaction with Mediterranean magmatic CO₂ characterized by heavier carbon isotope ratios ( value from -3 to 0‰ vs V-PDB (CAPASSO et al., 1997, GIAMMANCO et al., 1998; INGUAGGIATO et al., 2000) with respect to MORB value and/or input of CO₂-derived from thermal decomposition of marine carbonates have been inferred.     

吉林省油页岩中铂族元素的化学牲及分配规律研究

采用电感耦合等离子体发射质谱仪(ICP-MS)测定了吉林省油页岩中铂族元素的含量,并对油页岩中铂族元素的化学特征、与无机组分的相关性及其分布模式等进行了分析和阐述.通过油页岩中铂族元素的含量与地壳和中国东部出露地壳中铂族元素丰度的比较表明,Rh、Ru、Ir等元素相对富集,其中松原油页岩中Rh、Ir的含量约为地壳平均值的10倍.研究区油页岩中铂族元素以Pt-Pd分配模式为典型特征,一般Pt的丰度大于Pd.油页岩中铂族元素与无机组成相关分析的结果表明,油页岩中铂族元素可能呈吸附态存在于高岭石、伊利石等粘土矿物中.     

海洋球石藻(Emiliania huxleyi)活性物质分离鉴定及其抗菌抗氧化性能研究

以海洋球石藻Emiliania huxleyi为原料,提取分离生物活性物质,为该藻活性物质的研究与开发提供理论基础。通过对球石藻75%乙醇浸提物采用乙酸乙酯进行萃取,进一步利用薄层色谱、硅胶色谱、Sephadex LH-20凝胶色谱及高效液相色谱(HPLC)等方法,对化合物成分进行逐步分离纯化,获得纯度大于95%的单体化合物;通过~1HNMR、~(13)CNMR及HRMS等波谱分析技术鉴定化合物的结构,并对其抗菌、抗氧化性能进行初步分析。结果分离鉴定出3种单体化合物,分别为叶绿醇(C_(20)H_(40)O)、棕榈酸(C_(16)H_(32)O_2)和肉豆蔻酸(C_(14)H_(28)O_2),这些化合物均为首次从海洋球石藻中分离获得。其中叶绿醇具有较强的抗氧化能力,且对肝癌细胞Hep G2的增殖有较强的抑制作用,其他两种化合物对金黄色葡萄球菌、枯草芽孢杆菌及副溶血性弧菌均有不同程度的抗菌活性。另外,海洋球石藻中这些化合物除了具有一定的抗菌抗氧化性能外,可能在球石藻响应胁迫(如病毒感染)过程中也具有重要作用。     

近40年来对南海化学海洋学研究的新认知

作为西太平洋最大的边缘海, 南海在全球海洋和海洋学研究中占有重要地位。近40年来, 南海的化学海洋学研究取得了大量系统的新发现、新认识, 提出了不少新的理论观点, 对全球海洋学的发展进步做出了重要贡献。研究发现了南海次表层存在以海水亚硝酸盐为代表的生态环境参数极值现象, 不同参数水层深度范围不同, 由此形成的跃层生态系统有着与其他生态系统显著不同的特点。从系统研究获知, 南海碳循环过程十分复杂, 生物作用下的生物泵过程以及碳源汇区域和季节变化巨大, 南海碳源汇在不同的区域不同的时间的性质和强度迥异, 全年尺度上总体表现为大气二氧化碳的弱源。南海北部的珠江口邻近海域和深海盆的生态环境特征与化学物质循环和陆架边缘海、珊瑚礁等密切相关, 但又与陆架边缘海、珊瑚礁等显著不同, 表现为珠江口底层存在缺氧现象, 珠江口海域是一个以缺氧为特征的生态脆弱区。在系统认识南沙珊瑚礁生态系统物质循环快速、生物过程控制着化学物质的垂直转移的基础上, 提出了维持珊瑚礁生态系统高生产力的新机制——“拟流网理论”。对南海沉积物化学的系统研究认识到, 沉积物-水体化学物质循环有密切的耦合关系, 南海珊瑚礁或沉积岩心化学物质分布变化可反演其历史变化, 如南海冰期表层海水古生产力为间冰期的1.6倍; 晚中新世南海南部发生了一次“生物勃发事件”, 其生产力主要受季风和陆源营养物质输入量影响; 东北季风与西南季风在不同区域其影响程度不同等。40年来南海化学海洋学研究的这些新发现和新认识对系统揭示南海的海洋学过程奠定了强有力的基础, 未来南海化学海洋学研究也必将为南海资源环境的可持续利用提供科学支撑。     

Mineralogical and Chemical Composition of International Carbon and Oxygen Isotope Calibration Material NBS 19, and Reference Materials NBS 18, IAEA-CO-1 and IAEA-CO-8

International carbon and oxygen isotope calibration material NBS 19 and reference materials NBS 18, International Atomic Energy Agency (IAEA)-CO-1 and IAEA-CO-8 are prepared from naturally occurring rock specimens of marble and carbonatite. Mineralogical and chemical analysis showed that only NBS 19 and IAEA-CO-1 represent essentially pure samples of calcite containing < and minimal (< 1%) quantities of quartz. In contrast, both NBS 18 and IAEA-CO-8, although primarily composed of calcite, are contaminated by a range of additional phases. NBS 18 was estimated to contain 1% Fe-dolomite and trace (< 1%) quantities of apatite and quartz. IAEA-CO-8 was estimated to contain at least 4% non-carbonate material (including apatite, barite, biotite and magnetite). NBS 18 and IAEA-CO-8 are both derived from samples of carbonatite and the calcite component of each material is characterised by appreciable substitution of Mg + Mn + Sr ± Fe ± Ba (Σ ≈ 14000–15000 μg g^-1) for Ca. The observations reported in this study complement data in the literature detailing significant grain-scale isotopic heterogeneity in NBS 18 and IAEA-CO-8. Both data sets highlight the need for careful characterisation of calibration materials prior to distribution.     

Particle Dynamics and Trace Metal Reactivity in Estuarine Plumes

Iron, Mn, Cu, Pb and Zn have been determined in suspended particulate matter (SPM) collected in the estuarine plume regions of the Humber (during winter, spring and summer) and Thames (winter only). Metal concentrations (w/w) were found to increase with SPM concentration and could be defined in terms of the mixing of an ambient, slow settling population, with variable proportions of a diluent population. The end-members of the particle mixing series are fine material derived from coastal erosion, which is modified seasonally by biological production, and contaminated estuarine material which is contained within the estuarine discharge or derived from local resuspension of reworked deposits by tidal currents and wave activity. Iron-normalized metal concentrations exhibited an inverse relationship with SPM concentration in the Humber region and regression analyses enabled seasonal changes in end-member compositions to be evaluated. Since the metal:Fe ratios of the ambient population did not accord with those of local cliff samples, additional sources of metal were proposed whose importance to particle composition increases with a reduction in SPM concentration. Qualitatively, the seasonal variation of end-member compositions was consistent with (i) the coupling between redox processes occurring in the bed sediment and adsorption of metals (Mn, Cu, Zn) released from the pore waters onto ambient and diluent suspended particles in the overlying water column, and (ii) adsorption of metal (Pb) by ambient suspended particles from an extraneous (atmospheric) source. In the Thames plume, an increase in Fe-normalized metal concentrations with increasing particle concentration resulted from the mixing of end-member particles and the effects of additional metal from an internal or extraneous source were less clear, possibly because of metal desorption from suspended particles traversing the salinity gradient in the outer estuary. The processes described in this study regulate the internal cycling of trace metals in estuarine plume regions and the export of metals to neighbouring shelf sea environments.     

ANALYSIS OF BIOLOGICAL GEOCHEMISTRY OFCHEMICAL ELEMENTS IN Betula ermanii FORESTIN CHANGBAI MOUNTAINS,CHINA

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9. Life On Earth... And Elsewhere?

This concluding chapter is divided into two main parts. The first part is a summary of the main facts and events which constitute the present body of knowledge of the chronology of life in the solar system, in the form of “highlights” in astronomy, geology, chemistry and biology. The second part raises the interrogation “Is life universal?”, and tries to provide answers based on these facts and events. These answers turn out to differ widely among the various disciplines, depending on how far they feel able to extrapolate their current knowledge.     

Optical,Radiative and Chemical Characteristics of Aerosol in Changsha City,Central China

Industrial pollution has a significant effect on aerosol properties in Changsha City, a typical city of central China. Therefore, year-round measurements of aerosol optical, radiative and chemical properties from 2012 to 2014 at an urban site in Changsha were analyzed. During the observation period, the energy structure was continuously optimized, which was characterized by the reduction of coal combustion. The aerosol properties have obvious seasonal variations. The seasonal average aerosol optical depth (AOD) at 500 nm ranged from 0.49 to 1.00, single scattering albedo (SSA) ranged from 0.93 to 0.97, and aerosol radiative forcing at the top of the atmosphere (TOA) ranged from ?24.0 to 3.8 W m^?2. The chemical components also showed seasonal variations. Meanwhile, the scattering aerosol, such as organic carbon, SO₄^2?, NO₃^?, and NH₄⁺ showed a decrease, and elemental carbon increased. Compared with observation in winter 2012, AOD and TOA decreased by 0.14 and ?1.49 W m^?2 in winter 2014. The scattering components, SO₄^2?, NO₃^? and NH₄⁺, decreased by 12.8 μg m^?3 (56.8%), 9.2 μg m^?3 (48.8%) and 6.4 μg m^?3 (45.2%), respectively. The atmospheric visibility and pollution diffusion conditions improved. The extinction and radiative forcing of aerosol were significantly controlled by the scattering aerosol. The results indicate that Changsha is an industrial city with strong scattering aerosol. The energy structure optimization had a marked effect on controlling pollution, especially in winter (strong scattering aerosol).