基于频度统计和神经网络的北太平洋柔鱼渔场预报模型比较

利用2004~2010年北太平洋鱿钓船队生产数据和海洋环境数据,以海表温度(SST)1℃、海面高度(SSH)为1 cm、叶绿素a浓度(CHL-a)为0.1 mg/m3的间距,分析作业产量、CPUE与SST、SSH、CHL-a的关系,得到柔鱼渔场适宜环境因子范围,并将生产数据和环境数据匹配组成样本集,建立北太平洋柔鱼空间分布BP神经网络模型;利用2011年环境数据预报柔鱼渔场,并与2011年实际生产数据进行对比。结果表明,6~10月各月实际作业位置落入基于频度统计方法预报渔场的概率达90%以上;而BP模型预报的平均精度为79.2%,最低精度为52.5%。基于多环境因子的频度统计柔鱼渔场预报模型优于神经网络模型。     

地震应急通系统在尼泊尔8.1级地震应急中的应用

分析传统地震现场应急工作中存在的缺点和不足,介绍地震应急通系统的组成、架构设计和主要功能特点。对地震应急通系统在尼泊尔8.1级地震应急工作中的应用进行简单描述,并结合新技术和新思路,对地震应急通系统下一步的发展方向进行探讨和展望。实践证明,地震应急通系统帮助地震部门建立了一套功能全面、反应灵敏、运转高效的地震应急指挥体系,提高了地震部门应对地震事件的能力,具有较高的推广价值。     

山东地区新生代不同类型幔源样品中稀有气体同位素组成与成因

稀有气体是地球流体源区信息的有效示踪剂.利用热熔融法对山东地区幔源巨晶、包体全岩及其单矿物以及寄主玄武岩等幔源样品中稀有气体的测试表明,不同类型样品具有明显不同的稀有气体同位素组成,特别是He同位素比值差异明显.巨晶和包体单矿物中的n(3He)/ n(4He)值分别为0.87～11.31Ra、0.911 ～10.11Ra,均值分别为6.1Ra和3.73Ra,主体介于地幔一大气一地壳源区之间;包体全岩中n(3He)/ n(4He)值0.19 ～ 2.30Ra(均值为1.05 Ra),且均低于相应单矿物中该比值;而玄武岩中n(3He)/ n(4He)值全为10-8数量级,与地壳均值无异.各类幔源样品中n(4Ar)/n(36 Ar)值无明显差异,介于296.4～864.3,高于大气但远低于典型地幔值.所获有限数据中,不同类型样品中n(2Ne)/n(2Ne)值均高于大气,具幔源特征,其中包体全岩及其单矿物n(2Ne)／n(22Ne)值分别为10.19 ～12.42和10.55～11.80,无明显差异;玄武岩中该值介于11.07～13.10,总体高于包体全岩及其单矿物.上述比值特征的差异反映了不同类型幔源样品各自不同的成因和演化特征:巨晶和包体单矿物中的轻稀有气体同位素组成主要反映了由于古板块俯冲所导致的岩浆源区地幔一大气／地壳的昆合特征,个别样品中可能存在宇宙成因3He;除单矿物中所体现的源区混合特征外,包体全岩还存在放射成因4He;而玄武岩在喷出地表后丢失大量地幔稀有气体信息,其同位素组成主要体现了放射成因4He的影响.     

Graptolite‐Derived Organic Matter and Pore Characteristics in the Wufeng‐Longmaxi Black Shale of the Sichuan Basin and its Periphery

A key target of shale gas exploration and production in China is the organic-rich black shale of the Wufeng Formation-Longmaxi Formation in the Sichuan Basin and its periphery. The set of black shale contains abundant graptolites, which are mainly preserved as flattened rhabdosomes with carbonized periderms, is an important organic component of the shale. However, few previous studies had focused on the organic matter (OM) which is derived from graptolite and its pore structure. In particular, the contributions of graptolites to gas generation, storage, and flow have not yet been examined. In this study, focused ion beam-scanning electron microscope (FIB-SEM) was used to investigate the characteristics of the graptolite-derived OM and the micro-nanopores of graptolite periderms. The results suggested that the proportion of OM in the graptolite was between 19.7% and 30.2%, and between 8.9% and 14.4% in the surrounding rock. The total organic carbon (TOC) content of the graptolite was found to be higher than that of the surrounding rock, which indicated that the graptolite played a significant role in the dispersed organic matter. Four types of pores were developed in the graptolite periderm, including organic gas pores, pyrite moulage pores, authigenic quartz moldic pores, and micro-fractures. These well-developed micro-nano pores and fractures had formed an interconnected system within the graptolites which provided storage spaces for shale gas. The stacked layers and large accumulation of graptolites resulted in lamellation fractures openning easily, and provided effective pathways for the gas flow. A few nanoscale gas pores were observed in the graptolite-derived OM, with surface porosity lie in 1.5%–2.4%, and pore diameters of 5–20 nm. The sapropel detritus was determined to be rich in nanometer-sized pores with surface porosity of 3.1%–6.2%, and pore diameters of 20–80 nm. Due to the small amount of hydrocarbon generation of the graptolite, supporting the overlying pressure was difficult, which caused the pores to become compacted or collapsed.     

Three-Dimensional In Situ Stress-Field Simulations of Shale Gas Formations: A Case Study of the 5th Member of the Xujiahe Formation in the Xinchang Gas Field, West Sichuan Depression

This work established a geological model for the 5th member of the Xujiahe Formation (X5 member) in the Xinchang gas field of the West Sichuan Depression based on the lithological, structural and depositional properties, as well as logging and well completion data and drill-core observations. Rock mechanical parameters were calculated according to rock mechanic experiments and rock mechanic interpretations from logging data. We also calculated the magnitudes and orientations of the in situ stresses based on acoustic emission tests, differential strain tests, fracturing behaviour and logging interpretations as well as anisotropy logging tests, borehole-breakout measurements and well-log data. Additionally, the present stress field of the X5 member was simulated using finite element numerical (FEM) simulation methods. The numerical simulation results indicate that the distributions of lithology and fractures are key factors that influence the present stress field. The stress field in the study area is discontinuous as a result of fractures and faults in the central and eastern areas. Stress is concentrated at the end sections and bends of faults, but dissipates with distance away from both sides of the faults. A longitudinal profile clearly demonstrates the zonality and continuity of the stress field and an increase with depth. The differential stress distribution is relatively uniform; however, large deviations occur in fracture zones.     

大断面小净距隧道围岩稳定性数值分析 大断面小净距隧道围岩稳定性数值分析

结合小净距隧道工程特点,分别建立不同跨度小净距隧道有限元计算模型,对隧道施工过程力学特征及围岩稳定性进行对比分析,以研究三车道大断面小净距隧道区别于两车道小净距隧道的基本力学特征。分析结果表明,对应不同隧道跨度、隧道净距和围岩级别对隧道施工过程中围岩稳定性的影响有显著差别,相同隧道净距条件下,三车道小净距隧道围岩应力状态比两车道隧道差,净距越小,差别越大,而围岩质量越低,差别也越显著;另外,在质量较差的围岩中,大断面小净距隧道围岩受力最薄弱部位主要集中在岩柱雁形部,而两车道小净距隧道则为岩柱中部。研究结果可为大断面小净距隧道的设计、施工提供有益的参考。     

迭层石——(性质、分类和如何用于前寒武纪地层)

近年来,前寒武纪地层中各类金属、非金属等特大型矿床和具工业价值的油、气田不断被发现,因此世界各国对前寒武纪地质的研究普遍引起重视,并通过各种研究途径,尽快地建立前寒武纪地层系统,以进一步指导找矿和探矿。迭层石作为研究前寒武系的一种古生物手段,日趋被大家注意,试图用迭层石来解决前寒武系特别是震旦系的划分与对比。众所周知,我国震旦纪地层分布之广、出露之全、典型剖面研究之早,都是世界独一无二的,其中迭层石丰富程度也是世界少有的,这些事实,早被世界广大地质界所公认。但是苏修反动学者,出于反华、反共、反革命的目的,借口我国震旦纪地层研究的某些不足,恶毒攻击,妄图以“里菲”取代“震旦”的名字,真是痴心妄想。所以,我们加快震旦纪地层的研究工作,不仅具有实际意义,而且具有反修的政治意义。苏修的一位学者较系统地介绍了迭层石的研究现状,文中也反映出树“里菲”眨低“震旦”之意,所以在参阅时要持批判态度。但是,鉴於迭层石研究,目前还处于初期阶段,其分类、归属和鉴定标志以及使用价值都未定型,因此本着“洋为中用”的方针,去粗取精,去伪存真,尽快建立一套具有我国独特风格的迭层石研究方法,为捍卫我国震旦系是世界标准地层系统的一个组成部分,充实迭层石方面的依据,为伟大的社会主义祖国争光!     

新疆准东煤田西黑山勘查区西山窑组煤相特征

以新疆准东煤田西黑山勘查区西山窑组煤层为研究对象,采用成因参数法和煤相图解方法,同时结合沉积学方法进行煤岩、煤相分析,探讨泥炭沼泽类型及其演化规律。煤相参数研究显示,B1、B11、B21和B2煤层煤相总体为偏干燥的湿地森林和湿地森林沼泽,B12、B3和B4-5煤层总体为干燥森林沼泽;垂向上B1、B2、B3、B31和B6煤表现出显著的由湿地森林沼泽或偏干燥的湿地森林沼泽向干燥森林沼泽演化,反映覆水程度逐渐变浅,泥炭沼泽表面逐渐趋于干燥,表明成煤期泥炭堆积速率与基底的相对沉降速率持平或略高于基底沉降速率。     

准噶尔盆地吉木萨尔凹陷芦草沟组致密油形成条件与分布规律

利用准噶尔盆地吉木萨尔凹陷芦草沟组地质、试油、录井、岩石薄片及地球化学等资料,研究了致密油的形成条件、分布特征及其控制因素。研究区致密油形成条件优越,烃源岩有机质丰度高、有机质类型为Ⅰ和Ⅱ型并且为低熟-成熟阶段;储层岩性复杂,甜点段平面连续性好,孔隙类型多样;广泛分布的烃源岩与储层频繁互层,烃源岩生成的油气直接进入相邻储层,有利于致密油的富集;芦草沟组超压广泛发育,是致密油运移的主要动力。致密油纵向上分布受优质烃源岩控制,全段均见油气显示,主要富集于优质烃源岩层附近的储层中;平面上受烃源岩有机质丰度、烃源岩厚度及储层厚度的综合控制,主要分布于烃源岩厚度大于200 m、TOC高于35%、储层厚度大于15 m的区域之内