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151.
南沙群岛海域泻湖及礁外沉积物间隙水中的-2价硫 总被引:1,自引:1,他引:1
于1993年5月和1994年3-4月通过调查,用硫离子选择电极法研究南沙群岛海域泻湖及礁外沉积物间隙水中的∑S(-Ⅱ)及SO~(2-)_4,探讨泻湖内及礁外间隙水中-2价硫的分布特征,沉积物-海水界面间硫的扩散转移通量和-2价硫的热力学平衡控制体系。结果表明,该海区∑S(-Ⅱ)含量,泻湖间隙水中远比礁外高,人为活动剧烈的礁内泻湖高于人为活动少的泻湖,离礁近的礁外间隙水中的高于远离礁的间隙水中的。在礁外沉积物间隙水中-2价硫含量呈垂向增加的趋势,沉积物-海水界面间HS-,S2-均是从沉积物向上覆海水扩散,SO反之。礁内泻湖的扩散量远高于礁外的,HS-扩散总平均为61.34μmol/(m2·d),SO为-0.41mmol/(m2·d);礁外泻湖的HS-总平均为14.96μmol/(m2·d),SO为-0.35mmol/(m2·d)。该海区的-2价硫主要由S+2e→S2-氧化还原电对控制,平衡时Eh计算值与实测值接近,单质疏作为亚稳态可存在于沉积物中,并可与溶解铁继续形成自生黄铁矿(FeS2)沉淀。 相似文献
152.
台湾岛东北部龟山岛附近海域自然硫烟囱体的基本特征研究 总被引:2,自引:1,他引:2
龟山岛热液活动区位于冲绳海槽向西延伸的部位,菲律宾海板块向欧亚板块下方俯冲在此隐没,热液活动的出现为研究该地区进一步的发展提供了契机.龟山岛热液活动产生的烟囱体高度富集自然硫,几乎没有其它矿物结晶形成,烟囱体本身呈现分层现象,自然硫的含量也是从烟囱体的外层到内层依次增高,与烟囱体颜色上表观的分层呈现良好的对应关系.我们根据这种分层现象探讨了烟囱体的成因机制和热液流体随时间的变化特征,同时根据等离子质谱(ICP-MS)和X射线衍射仪(XRF)的实验数据分析了自然硫烟囱体存在两种物质来源:热液活动区基底的安山岩和地幔,但是对于地幔物质以何种形式加入到热液流体中还需进一步研究. 相似文献
153.
T.F. Sutherland J. Galloway R. Loschiavo C.D. Levings R. Hare 《Estuarine, Coastal and Shelf Science》2007,75(4):447-458
Both acoustic and sediment surveys were carried out in the Broughton Archipelago, British Columbia, in order to map a former aquaculture site and calibrate acoustic surveys with georeferenced sediment properties. The acoustic surveys included EM3000 Multibeam (including backscatter) and QTC VIEW™ (Series IV) technologies, while the geotechnical survey entailed Van Veen grab sampling of surface sediments and associated analyses. The two acoustic technologies were consistent in their ability to identify distinct regions of seafloor characterized by rock outcrops, consolidated substrates, or gel-mud depositional fields. Both multibeam backscatter data and QTC VIEW™ number-coded classifications were extracted across a range of circular areas located at each georeferenced sampling station (radii: 2, 3, 4, 5, 8, 12, 16, 20 m). Statistical correlations were observed between backscatter and certain geotechnical properties, such as sediment porosity, sediment grain size fractions (<2 μm, silt content), and particulate sulfur concentration. The areal resolution of backscatter extraction was explored in terms of determining a sensitive calibration technique between backscatter and sediment properties. In general the highest r2 values between backscatter and sediment variables were observed across extraction radii between 8 and 20 m. Such groundtruthing techniques could be used to interpolate seafloor characteristics between sampling stations and provide a steering tool for sampling designs associated with benthic monitoring programs. 相似文献
154.
海洋光合细菌的分离鉴定及其生长条件的研究 总被引:5,自引:0,他引:5
用红色硫细菌培养基从青岛沿海潮间带海泥中分离出8株光合细菌,经鉴定菌株HD_1属最小着色菌(Chromatium minutissimum),HD_2、HD_4为细着色菌(Chromatium gracile);菌株SL_1、SL_1x、PL_1和PL_2为嗜酸红假单胞菌(Rhodopseudomonas acidophila),菌株HCx为沼泽红假单胞菌(Rhodopseudomonaspalustris)。分离菌株均具运动性,不需生长因子。菌株HD_1、HD_2和HD_4在厌氧光照条件下利用硫化物,且在细胞内贮存硫粒。菌株HD_1、HD_2的最适盐度为4.0%,最适pH为7.0,8.0。当培养基中硫化物含量为0.01—0.04%时,菌株HD_1、HD_4生长良好。菌株PL_2在初始pH为6时生长最好。酵母膏对菌株HCx具有明显的促生长作用。 相似文献
155.
Sulfur isotopic composition of modern seafloor hydrothermal sediment and its geological significance
INTRODUCTIONDuringtheperiodofearly 1 980stomid 1 990s ,withtherapiddevelopmentofexplorationtotheseafloorhydrothermalactivities ,thesulfurisotopiccompositionofhydrothermasedimentsaroundtheworldhadbeencarriedouttosomeextent (ZierenbergandShanks ,1 988;BlumandPuchel… 相似文献
156.
主要研究了菲律宾东南海域(区域I)和伊里安岛东部的北部海域(区域Ⅱ)上层水(0~150m)化学参数pH,Eh,Es,∑S(-Ⅱ)和a^2-s等的分布特征和-2价硫的产生机制,结果表明,该海域表层南赤道逆流和次表层的赤道潜流是影响化学参数特别是DO和∑S(-Ⅱ)的主要因素,高生产力与高水温是赤道西太平洋上层水中-2价硫产生与保存的重要影响因素,区域Ⅱ中的pH,∑S(-Ⅱ)a^2-s,DO比区域I高而 相似文献
157.
Maja A. Lazzaretti Kurt W. Hanselmann Helmut Brandl Daniel Span Reinhard Bachofen 《Aquatic Sciences - Research Across Boundaries》1992,54(3-4):285-299
P, Fe, Mn, and S species were analyzed in water samples from the sediment-water interface collected at four seasonally different times during the course of a year at two sampling sites in the southern basin of Lake Lugano (Lago di Lugano). The results reveal the strong influence of the biogeochemical processes in the sediment on the chemical composition of the lake water above. Consumption of oxygen and nitrate under oxic to microoxic conditions in the water column as well as sequential release of reduced manganese and iron under anoxic conditions was observed as a direct or indirect consequence of microbially mediated degradation of organic matter. The seasonal pattern observed for the release and the retainment of dissolved reduced iron and manganese correlates well with the one for dissolved phosphate. Iron, manganese and phosphorus cycling are coupled tightly in these sediments. Both sediment types act as sinks for hydrogen sulfide and sulfate. An inner-sedimentary sulfur cycle is proposed to couple iron, manganese and phosphorus cycling with the degradation of organic matter. Nutrient cycling at the sediment-water interface might thus be driven by a microbially regulated electron pumping mechanism. The results contribute to a better understanding of the role of sediment processes in the lake's internal phosphorus cycle and its seasonal dynamics. 相似文献
158.
Shipboard measurements of atmospheric dimethyl sulfide were made during two transects along the east coast of the United States and at several stations in the Gulf of Maine. Limited measurements of carbon disulfide and hydrogen sulfide are also reported. The mean DMS mixing ratio was 29 pptv (=25, n=84, median 19 pptv) during the Atlantic transects, and 101 pptv (=67, n=77, median 79 pptv) in the Gulf of Maine. Distinct diurnal variations were found in the DMS data from the transects. The meteorology of the study area appears to control day-to-day differences in the magnitude of these diurnal variations, although rapid daytime oxidation is suggested in some cases. Diurnal variations were also evident in near-shore stations in the Gulf of Maine due to nocturnal boundary-layer inversion. Diurnal variation was not evident at other sites in the Gulf due to large scale changes in the atmospheric circulation pattern, which effectively masked any effects due to oxidation processes. Model simulations confirm that the DMS levels and diurnal variation found during the transects are not consistent with atmospheric oxidation processes alone. Atmospheric CS2 and H2S mixing ratios were less than 3 pptv during the transects, except for a single period of higher CS2 mixing ratios (reaching 11 pptv) during advection of continental air. Calculations of the flux of oceanic sulfur to the eastern United States show that the contribution of natural sulfur to the North American sulfur budget is small compared to anthropogenic sources. 相似文献
159.
Olivier Alard Ananuer Halimulati Lauren Gorojovsky Peter Wieland 《Geostandards and Geoanalytical Research》2023,47(2):437-456
Although sulfur is a relatively abundant element, measurement results with small uncertainties remain challenging to achieve, especially at S mass fractions below 100 μg g-1. We report > 1700 measurement results of S for thirty-seven geological reference materials including igneous, metamorphic and sedimentary rocks, and one soil. Measurement results were obtained in two laboratories (Macquarie GeoAnalytical and Géosciences Montpellier) over a long period of time ≈ 25 years (1997–2022), using several measurement procedures: X-ray fluorescence, high temperature iodo titration and elemental analysers equipped with thermal conductivity and/or infra-red detectors. Sulfur mass fractions for these diverse geological reference materials range between 5.5 and 11,395 μg g-1. While the comprehensive data set reported here should contribute significantly to a better characterisation of the S mass fractions of widely used geological reference materials, computed uncertainties, data distribution and comparison to published values still indicate heterogeneous distribution of S carrier(s) and analytical bias. 相似文献
160.
硫循环及硫同位素(δ34S)分馏研究对地表圈层的成岩作用具有重要意义,其中多种金属硫化物中硫同位素的分馏程度可以约束成矿热流体温度,进而作为地温计证据约束热液活动。四川盆地龙王庙组储集层内的热液改造影响着该储集层的非均质性,本研究着重讨论目的层中与热液成因白云石所伴生的黄铁矿(FeS2)-黄铜矿(CuFeS2)成矿现象:基于详尽的岩石学证据,应用纳米二次离子探针(NanoSIMS)对金属硫化物内部硫同位素分布进行测定,并基于热力学驱动下的硫化物间平衡分馏程度计算其成矿温度,进而约束层段内热液活动过程。研究发现:(1)微区硫同位素分布显示黄铁矿(FeS2)与黄铜矿(CuFeS2)沉淀过程中不仅存在热力学分馏,还存在动力学分馏现象,其中动力学分馏程度可以达到40.1‰,应用NanoSIMS微区测定手段可以有效剔除动力学分馏数据影响,获取热力学平衡分馏数据;(2)黄铁矿(FeS2)与黄铜矿(CuFeS2)成矿过程或利用不同的硫源,其中黄铁矿... 相似文献