龙须菜(Gracilaria lemaneiformis)多糖的分离纯化及其组成研究

以龙须菜粗多糖为原料,利用离子交换层析分离纯化,紫外光谱、醋酸纤维薄膜电泳和凝胶过滤层析法鉴定多糖的纯度及其分子量,同时进一步采用气相色谱分析龙须菜多糖的单糖组成.结果表明,利用蒸馏水、0.3mol/L NaCl和1.2mol/L NaCl溶液分步洗脱,DEAE-Sephadex A-25离子交换层析纯化得到龙须菜多糖的三个组分G1、G2和G3,得率分别为3.61%、69.26%、18.70%:G1、G2和G3均显示为单一电泳谱带和单一洗脱峰,无蛋白、核酸杂质,分子量依次为21993、48460、61031U;G2和G3的单糖组成主要为半乳糖、3.6-内醚半乳糖及少量葡萄糖;G2糖链通过1→2键与1→6键方式连接,存在非还原末端基及连三羟基,G3糖链则通过1→3键与1→2键方式连接.     

Gas hydrate stability zone modelling in areas of salt tectonics and pockmarks of the Barents Sea suggests an active hydrocarbon venting system

The Barents Sea seabed exhibits an area of major glacial erosion exposing parts of the old hydrocarbon basins. In this region, we modelled the gas hydrate stability field in a 3D perspective, including the effects of higher order hydrocarbon gases. We used 3D seismic data to analyse the linkage between fluid-flow expressions and hydrate occurrences above old sedimentary basin systems and vertical faults. Pockmarks showed a relation to fault systems where some of them are directly connected to hydrocarbon bearing sedimentary formations. The influence of bottom water temperature, pore water salinity and geothermal gradient variation on gas hydrate stability zone (GHSZ) thickness is critically analysed in relation to both geological formations and salt tectonics. Our analysis suggests a highly variable GHSZ in the Barents Sea region controlled by local variations in the parameters of stability conditions. Recovery of gas-hydrate sample from the region and presence of gas-enhanced reflections below estimated BSR depths may indicate a prevalent gas-hydrate stable condition.     

Seismic imaging of a fractured gas hydrate system in the Krishna–Godavari Basin offshore India

Gas hydrate was discovered in the Krishna–Godavari (KG) Basin during the India National Gas Hydrate Program (NGHP) Expedition 1 at Site NGHP-01-10 within a fractured clay-dominated sedimentary system. Logging-while-drilling (LWD), coring, and wire-line logging confirmed gas hydrate dominantly in fractures at four borehole sites spanning a 500 m transect. Three-dimensional (3D) seismic data were subsequently used to image the fractured system and explain the occurrence of gas hydrate associated with the fractures. A system of two fault-sets was identified, part of a typical passive margin tectonic setting. The LWD-derived fracture network at Hole NGHP-01-10A is to some extent seen in the seismic data and was mapped using seismic coherency attributes. The fractured system around Site NGHP-01-10 extends over a triangular-shaped area of ∼2.5 km² defined using seismic attributes of the seafloor reflection, as well as “seismic sweetness” at the base of the gas hydrate occurrence zone. The triangular shaped area is also showing a polygonal (nearly hexagonal) fault pattern, distinct from other more rectangular fault patterns observed in the study area. The occurrence of gas hydrate at Site NGHP-01-10 is the result of a specific combination of tectonic fault orientations and the abundance of free gas migration from a deeper gas source. The triangular-shaped area of enriched gas hydrate occurrence is bound by two faults acting as migration conduits. Additionally, the fault-associated sediment deformation provides a possible migration pathway for the free gas from the deeper gas source into the gas hydrate stability zone. It is proposed that there are additional locations in the KG Basin with possible gas hydrate accumulation of similar tectonic conditions, and one such location was identified from the 3D seismic data ˜6 km NW of Site NGHP-01-10.     

舒心片的质量标准研究

目的：建立中药舒心片中丹酚酸B含量的测定方法。方法：采用高效液相色谱法（HPLC）测定舒心片中丹酚酸B的含量,色谱柱为Agilent TC-C₁₈（2）色谱柱（4.6 mm×250 mm,5 μm）,以乙腈-0.1%的磷酸溶液（25∶75）为流动相;检测波长为286 nm;柱温为25℃;流速为1.0 ml/min。结果：供试品和对照品溶液中丹酚酸B与他峰分离度良好;在0.050～1.642 μg之间丹酚酸B呈良好线性关系,R=0.9993,丹酚酸B平均加样回收率为97.58%,RSD=0.25%。结论：经方法学验证,本法可用于舒心片的质量控制。     

植物挥发性有机物的分析方法

为了分析植物排放到大气中的挥发性有机物，在2000年1-6月期间，与美国国家大气研究中心（NCAR）的科学家共同发展和研究了一套自动的气相色谱系统和分析方法。该系统引入一个小型冰箱以除去空气样品进样时的水分，得到了对挥发性有机物样品进行分析时比较好的准确度。在5℃以及稳定的进样速率的条件下，可以得到比较好的除水效果。对NCAR附近的大气进行了采样，并利用此系统做了分析。本简单介绍此自动系统以及样品分析结果。实验结果表明，此套系统具有良好的重复性和稳定性，主要的挥发性有机物的成分如异戊二烯和单萜烯等具有明显的日变化。     

Particle Size Distribution and Gas-Particle Partition of Polycyclic Aromatic Hydrocarbons in Helsinki Urban Area

Ambient concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in Helsinki (Finland). Particle mass size distributions were obtained with a cascade impactor (12 stages) with glass fibre filters as substrates. Simultaneously with the impactor measurements, particulate and gaseous PAHs were collected on a quartz filter and XAD-2 adsorbent, respectively, for evaluation of gas-partition coefficients. Samples were analysed for PAHs by on-line coupled supercritical fluid extraction — liquid chromatography — gas chromatography — mass spectrometry. The impactor results showed that most of the PAHs in Helsinki urban area were concentrated in fine particles (<2.5 μm diameter) with unimode peak at about 1 μm. The results were comparable with the number distribution measured with a differential mobility particle sizer. Total amounts of PAHs (gas + particle) varied from 15 (acenaphthylene) to 1990 (fluorene) pg/m³. The PAHs lighter than 202 amu (pyrene and fluoranthene) were exclusively in gas phase, whereas those heavier than 202 amu were mostly associated with particles. A plot of the partition coefficients (logKp) versus the temperature dependent sub-cooled vapour pressures (logp _L ⁰ ) showed a gradient of −0.66, which deviated from equilibrium state (gradient = −1).     

Chemistry of organic traces in air

The occurrence of CH₂Br₂, CH₂BrCl, CH₂I₂, CH₂ClI, CHBr₃, CHBr₂Cl, CHBrCl₂ and CH₂Br-CH₂Br in marine air and seawater from various sampling sites in the region of the Atlantic Ocean have been measured and evaluated. A correlation exists between high concentrations of these compounds in air and in water and the occurrence of algae at the coastlines of various islands (The Azores, Bermuda, Tenerife) and in a region of high bioactivity in the Atlantic Ocean near the West African coast.Real-world air-water concentration ratios derived from measurements in the open ocean identify the water mass near the African coast with its high primary production as a source for the above compounds. This region has to be discussed also as a possible secondary source in which CHBr₂Cl, CHBrCl₂ and CH₂ClI can be formed via halogen-exchange. Whether CHBrCl₂ and CH₂ClI under-go transformation to CHCl₃ and CH₂Cl₂, respectively, is open to further investigations.Direct photolysis and degradation by OH-radicals lead to a gradient in the marine troposphere with reduced concentrations for the organobromides above the tropospheric boundary layer.Partly presented at: 2nd International Symposium on Biosphere-Atmosphere Exchange, Mainz, F.R.Germany, 16–21 March, 1986. Part VII: Chemosphere 15 (1986) 429–436.     

离子色谱法测定土壤中有效氟

利用离子交换-电导检测离子色谱法对土壤中有效氟进行测定。选用30 mmol/L氢氧化钾溶液作为淋洗液,流速1.20 mL/min,准确测定有效态(可提取态)氟含量。方法加标回收率为95%~108%,精密度好,检出限低,操作简单,对环境无污染,适合于土壤污染状况的调查。     

苏里格气田苏11区块山_1段储层展布特征

苏11区块是长庆油田公司在苏里格气田进行油气勘探开发的重点区块之一,油气勘探开发成效显著。为此,对该区块主要产层上古生界二叠系山西组山1段的构造特征、储层砂体展布特征等进行综合研究。运用测井解释等资料,进行区域小层精细划分和对比,建立该区统一的地层格架,研究山西组山1段顶面构造特征,对山1段的储层砂体及有效砂体展布特征进行分析研究,研究结果表明:1苏里格气田苏11区块山西组山1段顶面构造表现为一个宽缓的西倾单斜,具有东高西低的特征,发育多排宽缓且幅度较小的鼻状隆起构造;2该区山1段南北向砂体的连通性较东西向好,山1段有效砂体总体厚度小,分布零散,规模较小,仅局部叠置区厚度大,有效砂体非均质性强,连续性和连通性较差。     

苏里格气田苏54区块储层孔隙结构特征研究

鄂尔多斯盆地苏里格气田是我国最大的气田,但是储层岩性较为致密,已成为制约天然气勘探开发的主要因素,因此,开展储层孔隙结构特征研究对于该区天然气生产具有重要意义。通过扫描电镜、薄片鉴定、压汞、铸体薄片等分析测试方法对苏里格气田苏54区块储层微观孔隙结构进行了深入分析。结果表明：该区储层由北到南主要发育岩屑砂岩、岩屑质石英砂岩和石英砂岩;喉道半径普遍较小,孔喉分选较差,且以细孔径为主,孔喉连通性中等;孔渗普遍偏低,属低孔低渗,孔渗明显受沉积相带的控制,高孔渗区呈贯穿南北的条带状分布,与河道展布特征近似。研究表明物性高值区连片分布,东部好于西部,盒8下物性最好。