碱消解-高效液相色谱-电感耦合等离子体质谱法测定生物样品中的甲基汞和乙基汞

建立了碱消解-高效液相色谱-电感耦合等离子体质谱联用系统测定生物样品中甲基汞(MeHg)与乙基汞(EtHg)的分析方法。为提高灵敏度,选用微流量的PFA雾化器,在优化的检测条件下,MeHg及EtHg检出限可达到0.036μg/L和0.03μg/L;线性范围达到4个数量级,两条工作曲线线性相关系数为1。对1.78μg/L MeHg、1.65μg/L EtHg的混合标准溶液重复测定7次,色谱峰面积的相对标准偏差(RSD)分别为1.79%和1.44%。对标准物质BCR 464(金枪鱼)的分析结果表明,测定值与标准值基本吻合,但略低于标准值;甲基汞和乙基汞的加标回收率分别为85.9%和84.5%。高效液相色谱与质谱联用技术的高灵敏度和低检出限能够满足生物样品中汞形态定量分析的要求。     

Origin of Fe-Ti Oxide Ores in Mafic Intrusions: Evidence from the Panzhihua Intrusion, SW China

Economic concentrations of Fe–Ti oxides occur as massive,conformable lenses or layers in the lower part of the Panzhihuaintrusion, Emeishan Large Igneous Province, SW China. Mineralchemistry, textures and QUILF equilibria indicate that oxidesin rocks of the intrusion were subjected to extensive subsolidusre-equilibration and exsolution. The primary oxide, reconstructedfrom compositions of titanomagnetite in the ores and associatedintergrowths, is an aluminous titanomagnetite (Usp₄₀) with 40wt % FeO, 34 wt % Fe₂O₃, 16·5 wt % TiO₂, 5·3 wt% Al₂O₃, 3·5 wt % MgO and 0·5 wt % MnO. This compositionis similar to the bulk composition of the oxide ore, as inferredfrom whole-rock data. This similarity strongly suggests thatthe ores formed from accumulation of titanomagnetite crystals,not from immiscible oxide melt as proposed in earlier studies.The occurrence of oxide ores in the lower parts of the Panzhihuaintrusion is best explained by settling and sorting of densetitanomagnetite in the ferrogabbroic parental magma. This magmamust have crystallized Fe–Ti oxides relatively early andabundantly, and is likely to have been enriched in Fe and Tibut poor in SiO₂. These features are consistent with fractionationof mantle-derived melts under relatively high pressures (10kbar), followed by emplacement of the residual magma at 5 kbar.This study provides definitive field and geochemical evidencethat Fe–Ti oxide ores can form by accumulation in ferrogabbro.We suggest that many other massive Fe–Ti oxide depositsmay have formed in a similar fashion and that high concentrationsof phosphorus or carbon, or periodic fluctuation of fO₂ in themagma, are of secondary importance in ore formation. KEY WORDS: ELIP; Fe–Ti oxide ore; layered intrusion; Panzhihua; QUILF     

长牡蛎碱性磷酸酶的分离纯化及部分性质研究

本文以长牡蛎为酶源提取材料,用正丁醇抽提,硫酸铵分级分离,DEAE-52和Sephadex G-100柱层析,得到一定纯度的碱性磷酸酶,提纯倍数为61.96,比活力达1.326U/mg.该酶的最适pH值9.6,最适温度38℃,初速度6.8μmol/(dm~3·min),米氏常数Km值为1.30mmol/dm~3.实验结果表明,Mg~(2+)对该酶有明显的激活作用;Zn~(2+)、Cu~(2+)、Hg~(2+)对该酶有明显的抑制作用.     

Organic matter origin and distribution in suspended particulate materials and surficial sediments from the western Adriatic Sea (Italy)

In this study, organic carbon (OC), total nitrogen (TN), stable carbon isotopic (δ¹³C_OC) and CuO reaction product compositions were used to identify the sources of organic matter (OM) and to quantify the relative importance of allochthonous and autochthonous contributions to the western Adriatic Sea, Italy. Suspended particulate material (195 samples) and surficial sediments (0–1 cm, 70 samples) from shallow cross-shelf transects were collected in February and May 2003, respectively. Vertical water column profiles were acquired along the same transects. Data include depth, potential temperature, salinity, density and chlorophyll fluorimetry.Along the western Adriatic shelf in the near-shore region, the phytoplankton growth was influenced by dynamics of the buoyant plumes from the Po and Appennine rivers. A small amount of very fine terrigenous material remained suspended within the coastal current and was exported southward along the shelf to the slope. High variability in the bulk composition was detected in the Po prodelta surficial sediments, whereas the western Adriatic shelf, although a larger area, exhibited a narrower range of values.A significant decoupling was observed between suspended particles in the water column and surficial deposits. The organic material collected in the water column was compositionally heterogeneous, with contributions from marine phytoplankton, riverine–estuarine phytoplankton and soil-derived OM. Frequent physical reworking of surficial sediments likely leads to the efficient oxidation of marine OC, resulting in the observed accumulation and preservation of refractory soil-derived OC delivered by the Po and Appennine rivers.     

碱厂废水光谱特性实验研究

该文报道碱厂废水随浓度变化的光谱实验。分析碱厂废水的光谱特征 ,并与相同浓度的海水悬浮泥沙水体的光谱进行比较 ;确定该废水特征波长为 50 1.3nm。根据光谱实验结果 ,结合当前已有的水色传感器的资料 ,选择两个卫星传感器波段 :Sea WIFS第四频道 (497.2～ 52 1.6 nm)和TM第二频道 (518.9～ 6 0 0 .2 nm) ;利用数字对 (R,c) ,建立了反射率与该污染水体浓度间的相关模式。为遥感技术大面积、快速地监测碱厂废水污染水体提供理论依据。     

产复合酶菌株Pseudomonas sp.NJ197产酶发酵条件的研究

从南极普利兹湾深海900m的沉积物中筛选到一株同时产多种低温复合酶的菌 株NJ197,作者对其进行碳源、氮源、无机盐、起始pH值、培养时间、接种量等发酵条 件的优化实验．实验结果证明,在以0．5％可溶性淀粉为碳源,以0．5％豆饼粉为氮 源,无机盐:0．424％NH4H2PO4、0．075％K2HPO4、0．02％MgSO4、0．5％CaCO3,起始 pH值8．5,接种36h种龄的种子10％,20℃、250r／min的条件下在旋转摇床中培养 72h,产复合酶菌株产脂肪酶和淀粉酶活性最高．最佳的生理条件下复合酶中的碱性 脂肪酶和淀粉酶的产量分别提高到22．4U／cm3和30．9U／cm3,该产复合酶菌株可以 作为诱变育种、基因工程菌改造的出发菌株,在洗涤和制革工业中有良好的应用前 景．     

氯化物型盐碱地池塘底泥中水溶性盐的分布特征

1997－1999年夏天，对位于黄河下游的氯化物型盐碱地池塘底泥中的水溶性盐进行了分析。结果表明：底泥中的含盐量，SO^2-4,Ca^2 ,Mg^2 含量是随着塘龄的增加而升高，而其余离子基本不随塘龄的增加而变化。各离子的垂直分布为“泥－土”混合层的含量较低，“水－泥”交界层含量较高。     

基于色层图与纹理融合的地形晕渲

针对三维地形晕渲的具体需求和存在问题,提出了一种基于色层图与纹理融合的晕渲方法。根据自定义或色层表主色调插值生成色彩连续的色层图,对地形高程进行着色;在地表材质分块的基础上,通过计算相邻材质边界上的多重纹理坐标,使用多重纹理映射进行融合过渡;最后给出了实验结果。     

物权法对节约集约利用土地的法理解析——以青岛市崂山区分层出让建设用地使用权为例

土地资源具有稀缺性和不可再生性,土地供给日渐紧张,拓展土地利用空间、将土地利用由平面趋向立体化发展的趋势日渐成熟。青岛市崂山区将建设用地使用权分层出让,不但垂范了法规政策,对区域经济的发展也具有很大的现实意义。     

流体在岩浆型铬铁矿和铂族元素成矿过程中的作用及意义

镁铁- 超镁铁岩是揭示地幔物质组成和壳幔相互作用的重要窗口，也是Ni- Cu- PGE- Cr等金属矿产资源的重要载体。不同的镁铁- 超镁铁岩体赋矿特征明显不同：蛇绿岩以产出铬铁矿床为特征，阿拉斯加型岩体主要赋含铂族元素(PGE)矿床，大型层状岩体则可同时产出铬铁矿床、PGE矿床和Cu- Ni硫化物矿床。这种成矿差异显然与赋矿岩体形成的构造背景、母岩浆经历的岩浆演化过程有关，但缺少关键控制因素的研究。前人对上述不同种类矿床的研究工作主要集中于地幔源区的部分熔融、上升过程中或岩浆房内的围岩混染和结晶分异等岩浆过程，而极少关注流体作用。近年来，实验岩石学和岩石地球化学的研究均表明幔源岩浆演化过程中的流体活动可能对成矿元素的富集迁移起到至关重要的作用，同时这些成矿元素的赋存状态和分配系数也在不断更新。厘清Cr和PGE在熔体演化——尤其是流体出溶过程中的地球化学行为，刻画并揭示其迁移富集、分离和再富集的成矿过程及控制因素，已成为当前岩浆矿床研究的热点。本文围绕富水流体与铬铁矿和PGE成矿关系的科学问题，总结了不同镁铁- 超镁铁岩体的成矿差异以及铬铁矿和PGE矿床成矿过程中的流体活动记录，提出流体性质和组分对铬铁矿和PGE迁移富集的控制作用，强调有必要开展蛇绿岩、大型层状镁铁- 超镁铁岩体和阿拉斯加型岩体的对比研究。