条斑紫菜低覆盖度基因组草图分析

对条斑紫菜（Porphyra yezoensis）进行Solexa高通量测序,获得低覆盖度全基因组草图。该基因组草图大小约220Mbp,GC质量分数53．08％;包含26629个预测基因,其中16409个基因具有内含子,平均每个基因含2．22个内含子;基因结构分析表明具有内含子的基因平均长度为2214bp,内含子平均大...     

全球流体通道网

新近取得的深反射与全球地震层析成像资料,为地球内部结构和流体通道的研究提供了一些依据．通过研究这些地震资料,可以了解地球内部物质分布状态的几何模式．综合研究表明,地球内存在流体通道网,它连通地球外核、中幔圈、软流圈和岩石圈,是固体地球系统的重要组成部分．这种通道网络象“动脉”那样把地球外核中的流体和热量向外传送,但与热羽说不同的是,不见得有对应的“静脉”存在以保持地幔质量平衡．固体地球作为多层次多要素的巨型复杂系统,其动力学过程要用浑沌理论去解释．研究地球流体活动的轨迹和吸引子,将有助于深入了解地球活动的规律性．     

倾角导向体控制的气烟囱识别技术及其在海拉尔盆地贝尔凹陷中的应用

在调研了国内外气烟囱研究成果与思路的基础上,通过全新的地震解决方案——OpendTect平台提供的基于属性多层感知器(MLP)的人工神经网络(ANN)的方法预测气烟囱的发生概率体,并利用倾角导向体对算法进行改进,提出倾角控制下的地震气烟囱识别技术,很好地补充并发展了模式识别技术在地震勘探领域的应用。通常该技术一方面可以解释运移通道和浅层气成藏的原因;另一方面,形成的气烟囱地震数据体还可以预测源岩的发育情况;此外,对于判别断层封闭性也非常适用。最后应用这一技术对海拉尔盆地贝尔凹陷一含油区块的运移通道和成藏规律进行研究,分析该研究区的断裂发育特征和运移通道类型,总结了油源、通道、储层和盖层的空间配置关系,并建立相应的成藏模式。     

中国铁路客运网络可达性空间格局

基于铁路客运的基本特点,文章采用空间距离、时间距离、连接性、可选择性等多项指标对我国铁路客运网络可达性空间格局进行了分析。各项指标侧重点不同导致其反映的空间格局的明显差异。空间、时间距离指标均呈现以郑州为核心的中心－外围格局,但前者由中心向外围呈环状各向同性衰减,后者表现为各向异性,沿若干铁路干线衰减速度较慢; 连接性指标中东部地区优于西部,中心地区优于边缘,而可选择性指标东西分异显著,京广线以东(含京广沿线)地区明显优于西部地区。从空间均衡角度,主要体现铁路客运基本服务的空间距离、时间距离、连接性三指标相对较好,但偏重于高级服务的可选择性空间分布相对不均衡。主要铁路枢纽中,北京、上海、郑州、武汉等全国性铁路枢纽可达性明显优于广州、成都、兰州和沈阳等区域性枢纽。     

Gas-Phase Formation of Water-Soluble Organic Compounds in the Atmosphere: A Retrosynthetic Analysis

Atmospheric particles contain a myriad of organiccompounds, including many multifunctional,water-soluble organic compounds. Many of thesecompounds are postulated to be secondary of origin. This work investigates the possible precursors ofseveral classes of multifunctional, water-solublesecondary organic compounds by analyzing the pathwaysleading to their formation, based on known gas-phasereactions. The analysis is termed `retrosynthetic'due to the backward direction of the analysis, fromproducts to precursors. Pathways for multi-functionalcompounds were generated combinatorially, consideringthe formation of one functional group at a time.Many multifunctional organic compounds with carboxylicacid, carbonyl, and hydroxy functional groups werefound to be first- or second-generation products ofcommon anthropogenic and biogenic volatile organiccompounds such as alkanes, alkenes, aromatics, andcyclic alkenes. The estimated yields of water-solubleorganic compounds from primary precursors ranged fromless than 1% to over 10%, based on stoichiometricconsiderations. The SOA formation index, whichcombines the concepts of yields and rates, was used tocompare the feasibility of the retrosyntheticpathways. Many of the candidate pathways involve theisomerization reaction of alkoxy radicals andoxygenated intermediate products such asmonocarboxylic acids and hydroxyaldehydes.     

多尺度孔隙岩石的核磁共振扩散耦合现象及其探测方法

油藏岩石的孔隙连通性是反映流体渗流难易程度的重要参数,对渗透率、有效孔隙度等岩石物理参数的评价具有重要作用.连通的孔隙中,核磁共振(NMR)弛豫的交换会产生扩散耦合现象,可作为孔隙连通性的表征和探测方法.本文提出利用横向弛豫T2-T 2脉冲序列测量岩石的扩散耦合现象.运用随机游走方法模拟多孔岩石的核磁共振响应特征,分析...     

柴达木盆地三湖地区第四系生物气的形成途径与运聚方式

柴达木盆地三湖(台吉乃尔湖、涩聂湖、达布逊湖)地区第四系生物气区是我国最大的生物气区。笔者系统采集了该气区21个天然气样品,测量了其组分和碳同位素组成,重点探讨了生物气形成途径和运聚方式。生物气δ~(13)C_1和δ~(13)C_(CO_2)均随深度增大而变重,显示了CO_2还原途径成气的特征。生物气δ~(13)C_1、δ~(13)C_(CO_2)和δD分布与CO_2还原方式形成的生物气的相应同位素值分布范围接近。在有关成因图解中这些数据主要位于CO_2还原途径成气范围内。生物气CO_2和CH_4之间的碳同位素分馏系数α_c>1.055,具有CO_2还原途径成气的特征。柴达木盆地第四纪干旱的古气候、较低的古温度、较高的沉积速率和水体中较高的硫酸盐含量使得甲烷菌的大量繁殖只能在较大的深度范围内才能实现,从而,有利于CO_2还原途径成气作用进行。涩北一号、涩北二号气田生物气δ~(13)C_1组成分布可能表明,生物气形成以后沿疏导层水平运移进入气藏,基本不存在垂向运移。该项研究对于进一步深入探讨生物气成因、形成条件,确定生物气模拟实验方式与条件,计算生物气资源量,建立成藏模式和选择天然气有利勘探区块均具有重要价值。     

库车褶皱冲断带天然气成藏体系及有效运移优势通道

库车褶皱冲断带天然气成藏体系由侏罗系煤系烃源岩、侧断坡断层输导体系和侧断坡相关背斜构造圈闭构成.相对于走滑断层而言, 侧断坡断层是有效的天然气运移优势通道.研究表明, 侏罗系煤系生成的天然气通过侧断坡断层向上运移到白垩系巴什基奇克组侧断坡相关背斜的砂岩储集层聚集成藏, 异常压力的幕式泄压可能是油气运移的主要方式.克拉2、迪那2、迪那1和吐孜1等气田的发现是库车褶皱冲断带天然气成藏体系的有效体现.侧断坡相关背斜是库车褶皱冲断带天然气勘探的新领域.      

Origin of Oils in “Subtle pools” in the Dongying Depression, Bohai Bay Basin, China

Subtle traps or oil pools have become an important exploration play in the Dongying Depression, Bohai Bay Basin, east China. Despite recent successes in exploration, the formation mechanisms of subtle traps are still not well understood. The majority of subtle oil pools in the Dongying Depression are developed in the middle interval of the Es3 Member of the Paleogene Shahejie Formation with the subtle traps being primarily of lenticular basin-floor turbidite sands encompassed in mudstones. Oil in the subtle traps was previously thought to have migrated directly from the surrounding source rocks of the same formation （Es3）. Detailed geochemical investigation of 41 oils and 41 rock samples from the depression now indicates that the oils from the subtle traps cannot be correlated well with the surrounding Es3 source rocks, which are characterized by high Pr/ Ph （〉1）, low Gammacerane/C30hopane, representing a freshwater lacustrine setting. In contrast the oils features low Pr/Ph （〈1） and relatively high Gammacerane content, showing a genetic affinity with the underlying Es4 source rocks, which also have the same qualities, indicating a brackish lacustrine setting. Oils in the Es3 subtle traps are probably derived from mixed sources with the contribution from the upper Es4 source rocks predominating. Therefore unconventional oil migration and accumulation mechanisms need to be invoked to explain the pooling of oils from the ES4 source rocks, which probably came through a thick low interval of the Es3 source rocks with no apparent structural or stratigraphic pathways. We suggest that the subtle oil migration pathway probably plays an important role here. This finding may have significant implications for future exploration and the remaining resource evaluation in the Dongying Depression.     

油气成藏机理研究进展和前沿研究领域

随着地质工作者刻划和认识地下地质体构成、结构的能力及研究和预测沉积盆地能量场（温度场、压力场和应力场）及其演化能力的不断提高，以流体流动和油气运移为核心的油气成藏机理研究取得了重要进展：（1）证实了油气的优势通道运移并妆步提示了优势运移通道的微观和宏观控制机制，从而使基于油气运移路径三维预测的油气藏定位预测成为可能；（2）证实了幕式快速成藏过程并初步揭示了幕式成藏的驱动机制、有利场所和地球化学识别标志，突破了油气成藏是一个缓慢渗流过程的传统模式；（3）深盆气勘探和成藏机理研究取得了进展，从而突破了背斜成藏的传统观念，使“向斜”（盆地凹陷区）成为一些盆地寻找大型天然气藏的重要场所。沉积盆地深层油气成藏过程和保存条件、活动构造背景下油气晚期快速成藏过程是油气成藏机理研究的重要前沿研究领域。