西沙石岛西科1井生物礁碳酸盐岩地球化学特征

对西科1井生物礁碳酸盐岩样品进行了地球化学(常量组分、微量及稀土元素含量等)分析, 旨在探讨生物礁的形成演化以及所记录的环境变化信息.结果表明: 西科1井岩心在井深36 m附近存在地球化学参数的显著变化, 暗示该深度是一处重要的地层界面或环境突变界面.岩心中的常量组分可以分为3类组合: 以CaO为主, 辅以K₂O的原生碳酸岩组分, 该组分对应的主要造岩矿物是方解石, 代表了未经白云岩化的生物礁原生碳酸盐沉积; 以MgO为主, 辅以Na₂O和P₂O₅, 代表了白云岩化作用中的富集组分, 反映了相对封闭的泻湖环境; 以SiO₂为主, 加以Al₂O₃、TiO₂、Fe₂O₃和MnO, 代表造礁生物对这些组分的富集作用, 但不能排除火山组分少量混入的可能性.相对于全球第四纪碳酸盐岩、上陆壳及页岩的平均值, 岩心碳酸盐岩中大部分微量元素和稀土元素含量都较低.岩心中氧化还原敏感性微量元素(RSE)含量较低, 指示岛礁发育过程中大部分时期处于氧化环境条件下, 而RSE含量在岩心中的大幅波动体现出氧化/还原环境的交替变化.微量元素含量、ΣREE、ΣLREE、ΣHREE、LREE/HREE、δCe、δEu等地球化学指标在岩心中的分布与岩心样品的矿物组成无明显的相关性, 说明成岩作用和白云岩化作用并没有造成微量和稀土元素含量及特征指标的明显变化.      

Sequence polymorphism of two major histocompatibility (MH) class II B genes and their association with Vibrio anguillarum infection in half-smooth tongue sole (Cynoglossus semilaevis)

Major histocompatibility complex (MHC) class Ⅱ B molecules play an important role in the adaptive immune response in fish. Previous study has reported that two highly polymorphic class ⅡB genes, Cyse-DAB and Cyse-DBB exist in half-smooth tongue sole (Cynoglossus semilaevis). In this study, the polymorphism within exon 2 of the class Ⅱ B genes following bacterial challenge was evaluated. Two hundred C. semilaevis individuals were injected intraperitoneally with Vibrio anguillarum. Muscle tissue from the first 20 dead and 20 of the survivors was collected for genotyping. Sixty alleles from the 40 individuals were isolated, of which 32 belonged to Cyse-DAB and 28 belonged to Cyse-DBB. The rate of dN (non-synonymous substitution) was higher than that of dS (synonymous substitution) in the PBRs (peptide binding residues) of both class Ⅱ B genes. Conversely, the rate of dS was higher than dN in the non-PBRs and the complete exon 2 sequence. Thus, the results suggest that positive selection has occurred in the PBRs and purifying selection in the non-PBRs and exon 2. Thirteen class Ⅱ B alleles were used to study the association between alleles and resistance to infection. Though not significant, alleles Cyse-DAB*0601, Cyse-DAB*0706, and Cyse-DBB*0101, Cyse-DBB*1301 were only found in surviving individuals and may represent alleles that have resistance against V. anguillarum infection. Alleles Cyse-DAB*0701 and Cyse-DAB*1301 were significantly more prevalent in dead individuals than in surviving ones and may represent alleles that are associated with increased susceptibility to V. anguillarum infection.     

我国水资源研究与发展的若干思考

我国水资源具有人均占有量少、时空分布不均、水土资源不匹配、人类活动影响显著等特点,加上经济社会快速发展造成水资源供需矛盾突出,水资源态势十分严峻。切实实行最严格水资源综合管理、提高水资源利用效率、建设水资源安全保障的科技支撑体系,关系到我国全面建设小康社会的大局。分析了当前水资源研究的发展趋势,总结了国内研究现状与不足...     

S‐Doped Magnetic Mesoporous Carbon for Efficient Adsorption of Methyl Orange from Aqueous Solution

A simple and rapid soft‐templating coupled with one‐pot solvent thermal method is developed to synthesize S‐doped magnetic mesoporous carbon (S‐doped MMC). In this method, phenolic resin is used as a carbon precursor and Pluronic copolymer P123 is used as a template and 2,5‐dimercapto‐1,3,4‐thiadiazole is used as sulfur source. Prepared S‐doped MMC processes a high specific surface area, the Fe₃O₄ particles are well embedded in the mesoporous carbon walls that exhibit a strong magnetic response, and the hydrated iron nitrate loading amount of 0.808 g is the best. Batch adsorption experiments are carried out at different pH, initial concentration, temperature, and contact time on the adsorption of methyl orange (MO) by S‐doped MMC. The kinetic data of the adsorption process are better fitted with pseudo‐second‐order model than the pseudo‐first‐order model. Langmuir model is more suitable for the equilibrium data than Freundlich model. The thermodynamic parameters including ΔG⁰, ΔH⁰, and ΔS⁰ indicate that the adsorption is a feasible, spontaneous, and endothermic process. Finally, it is found that the coexistence of PO₄^3?, NO₃^?, SO₄^2?, Cl^?, and CO₃^2? does not influence the adsorption process. These results illustrate S‐doped MMC can be an efficient adsorbent for the removal of MO from wastewater.     

A new type of interaction between generalized Chaplygin gas and dark matter

In this paper, we investigate the model with a new type of interaction between generalized Chaplygin gas (GCG) and dark matter. It is shown that there exists a stable scaling attractor, which provides the possibility to alleviate the coincidence problem. The equation of state (EoS) of GCG approaches the attractor phase from either w _g >?1 or w _g w _g w _g w _g >?1), and next cross again the phantom divide (the transition from w _g >?1 to w _g Q can change its sign from Q<0 to Q>0 as the universe expands, which is different from the usual interaction. Moreover, we investigate the model from statefinder viewpoint. The statefinder diagnostic can not only discriminate the model with different coupling constant but also distinguish the model from other dark energy models.     

1-D and 2-D analyses of weak motion data in Fraser Delta from 1966 Duvall earthquake

The 1996 Duvall earthquake in Washington State triggered ground motion stations in the Fraser Delta, British Columbia, located on varying depths of Holocene and Pleistocene soils to a maximum depth of 800 m and one station on bedrock. Recorded ground motions were used to examine the applicability of 1-D and 2-D site response analyses for amplification studies in the Delta. 1-D response analysis gave a good indication of the period of peak response. Response spectra computed by 1-D analysis did not compare well with recorded spectra except at very deep sites. The use of 2-D analyses to include buried topography generally improved the predictions of site response spectra at the shallow sites. However, for the shallow earth sites, the recorded motions showed a strong spectral response at short periods in the range of 0.1–0.25 s. Neither 1-D nor 2-D analysis predicted this response.     

松辽盆地深层天然气运移通道研究

松辽盆地的形成伴随着上地幔软流层的阶段性上隆。在上地幔软流层上隆的过程中,刚性上地幔和下地壳发生张性断裂,汇聚在软流层中的烃类物质沿这些张性断裂上升到中地壳,并在富有储集空间的中地壳驻留。随着上地壳正断层阶段性沉降,驻留在中地壳的烃类物质沿上地壳正断层上升到盆地沉积层。烃类气体在上升路径遭受氧化则形成二氧化碳气藏,未遭受氧化则形成烃类气藏。玄武岩浆上升通道也是幔源气上升通道,工业气藏多分布于火山通道相储层。幔源气运移通道研究将提高深层天然气探井成功率。     

地下储层构型表征:现状与展望

地下储层构型表征是近十几年发展起来的油气藏开发地质研究方向。与露头构型分析不同的是,地下储层构型表征主要依据地震信息和多井信息,相应地发展了两类方法,其一为地震沉积学(地貌学)方法,即通过三维地震资料地层切片等方式,利用地震成像特征研究沉积单元的分布;其二为多井模式预测方法,即通过将不同级次的定量构型模式与地下井资料(包括动态监测资料)进行拟合,分级约束并预测不同级次的构型单元的井间分布。论述了这两类方法的起源、基本原理、应用范畴及存在问题,并根据油田生产要求与技术发展提出了进一步深入研究的方向,包括三维定量构型模式的深化研究、储层构型地震响应及解释方法研究、多井模拟拟合方法的改进与创新等。     

大兴安岭南段多金属成矿带硫、铅同位素组成及其地质意义

大兴安岭南段是我国北方重要的多金属矿床成矿带,对其成矿物质来源的分析研究有利于区域成矿规律的总结。在前人的工作基础上,对典型矿床的矿石矿物进行了硫、铅同位素研究。结果表明:闪锌矿、方铅矿、毒砂、黄铜矿、辉钼矿等硫化物的δ34S值主要变化范围为-6‰～4‰,平均值为0‰,峰值出现在0‰～2‰,呈塔式分布;无明显的重硫、轻硫富集,说明硫源较单一;矿石矿物及岩石的206 Pb/204 Pb、207Pb/204Pb、208Pb/204Pb值的变化范围主要集中在18.13～18.74、15.38～15.68和37.1～38.93,其平均值分别为18.38、15.54和38.09。同时,数据结果显示:成矿带的东部与西部存在较为明显的铅同位素差异,西部矿床中铅的分布主要集中在造山带演化线附近,而东部矿床中铅主要集中分布在上地幔和造山带演化曲线附近。     

汶川地震中强震持时的特征研究

基于汶川地震断层距150 km内56个台站三分量加速度记录分析地震动重要持时的特征,并建立了持时与断层距的拟合关系。与已建立的持时公式比较,以往分析结果都大大低估了汶川地震动持时。近断层特征对地震动持时有显著影响。断层距小于30 km,上盘和下盘场点的持时明显低于平均水平;断层距大于30 km,地震动持时受到下盘效应的影响,持时较长。破裂方向性效应引起地震动持时在垂直断层方向与水平方向上的差异,同时断层破裂前方向场点的地震动持时较短,比破裂后方向场点的持时小近一倍。