Characteristics of “Guangyuan-Wangcang” trough during Late Middle Permian and its petroleum geological significance in northern Sichuan Basin, SW China

Based on outcrop characteristics, combined with regional tectonic background, drilling and geophysical data, the sedimentary characteristics of the Middle Permian Maokou Formation in the northern Sichuan Basin was studied by means of macroscopic and microscopic observation, geochemical element test, total organic carbon content and vitrinite reflectance measurement. There is a set of deep-water sediments rich in organic matter in the Guangyuan-Wangcang area of northern Sichuan during the late depositional period of the Middle Permian Maokou Formation. The strata are distributed from northwest to southeast, with thickness of 10–30 m, mainly composed of siliceous rocks and siliceous mudstones, intercalated with gravity flow deposits. Siliceous rocks and siliceous mudstones are characterized by thin single layer, flat bedding and rich siliceous radiolarians, calthrop and brachiopod with small body and thin shell, belonging to the typical sedimentary characteristics of deep-water trough facies. The contents of Cu, Co, Mo, Ni and the ratio of Ni to Co in the geochemical tests all indicate that the siliceous rocks are products of deep-water reducing environment. The TOC value ranges from 3.21% to 8.19%, with an average of 5.53%, indicating that the siliceous rocks have good hydrocarbon generation ability. The south side of the trough is in platform margin facies with high energy, and the sediments are mainly thick massive micritic-calcsparite biogenic(clastic) limestone, which is conducive to the formation and evolution of the reservoir. During the late sedimentary period of the Maokou Formation, the northward subduction and extension of the oceanic crust at the northwestern margin of the Yangtze Plate provided the internal dynamic conditions for the formation of the "Guangyuan-Wangcang" trough. According to the location, sedimentary characteristics and formation dynamics of the trough, it is similar to the "Kaijiang-Liangping" trough during Late Permian proposed by previous researchers. It is believed that the "Kaijiang-Liangping" trough already had its embryonic form during the Late Middle Permian.

Characteristics of Authigenic Pyrite and its Sulfur Isotopes Influenced by Methane Seep--Taking the Core A at Site 79 of the Middle Okinawa Trough as an Example

Objective Authigenic pyrite often develops extensively in marine sediments,which is an important product of sulfate reduction in an anoxic environment.It has a specific appearance and complicated sulfur isotopic properties,and acts as important evidence of methane seep in marine sediments.Strong AOM（anaerobic oxidation of methane）activity has developed in the Okinawa Trough.

Aeromagnetic Interpretation of Basement Structures and Geometry in Parts of the Middle Benue Trough,North Central,Nigeria

The research of an analysis of aeromagnetic data collected in the middle Benue Trough in north-central Nigeria is presented.A detailed analysis of basement structures is conducted in order to identify regions with high hydrocarbon potential that is different from those discovered by earlier researchers.Aeromagnetic data were filtered by using the Butterworth and Gaussian filters,transformed by engaging the reduction to the equator technique,and subsequently enhanced.To estimate magnetic basement depths at various places throughout the basin,the Euler deconvolution depth weighting approach was used.Eleven(11)sub-basins with depths ranging from-2000 m to-8000 m were also identified by Euler’s findings.The sub-basins trend in the NE-SW direction while the average sediment thickness is found to be more than 3 km.The extracted structural features indicate areas like Kadi Blam and Kado areas in the southeastern part and Ogoja and Obudu in the southern part of the study area as regions with high structural densities.These areas coincide with the areas delineated as the sub-basins.The cross-sections generated reveal depressions caused by the action of some tectonic activities in the area.This study identified undulat­ing basement topography believed to be due to tectonic activities as well as five areas that are possible targets for hydrocarbon exploration.

中部槽构件摆动电弧窄间隙GMAW焊接接头组织及性能研究

采用摆动电弧窄间隙GMAW对中部槽所用50 mm厚ZG/NM异种钢组合进行了非对称填充式双面焊接。焊后在垂直于焊缝方向切取金相试样进行微观组织观察,同时取样进行力学性能测试,包括硬度测试和拉伸试验。试验结果表明:摆动电弧GMAW有效抑制了侧壁未熔合缺陷,未出现裂纹;不同填充层由于焊接规范差异,导致组织有所不同;所表征各填充层拉伸性能表现良好,与填充金属性能相当,其中深U型一侧底层强度最高,单道V型填充层强度介于U型顶部与底部之间;接头填充金属的硬度随位置发生变化,从U型一侧到V型一侧,硬度值逐渐降低。不同填充层,母材硬度值最高,填充金属硬度值最低,接头强度与硬度的差异主要归因于焊缝金属中铁素体的含量与形态。

中部槽构件摆动电弧窄间隙GMAW不同打底衬垫焊接成形及组织性能

【目的】进行I形坡口窄间隙焊接时通常涉及到使用衬垫,不同材料的衬垫会对窄间隙焊接打底焊缝的显微组织及力学性能产生影响。为了研究不同打底衬垫对焊接过程的影响规律,该文采用窄间隙摆动电弧GMAW并配合使用陶瓷、铜及钢3种不同材料衬垫对中部槽所用的50 mm厚的ZG30SiMn/NM450(简称ZG/NM)组合进行了焊接。【方法】焊接完成后,对打底焊道进行了显微组织观察、硬度及拉伸等力学性能测试。【结果】试验结果表明,在摆动电弧的作用下,成功抑制了焊缝的侧壁未熔合缺陷,体现出窄间隙摆动电弧GMAW对ZG/NM构建具有良好的适应性。由于衬垫材料的不同,接头打底焊道过热区宽度与组织及焊缝组织存在差异。过热区随衬垫导热系数的升高逐渐变窄,晶粒尺寸逐渐减小,焊缝中块状铁素体含量也逐渐变少。焊缝中心硬度最低,由于冷却速率的差异,导致陶瓷衬垫焊缝中心的硬度最低,而水冷铜的硬度最高。水冷铜打底焊道的高强度归因于较低的块状铁素体含量。【结论】该研究通过窄间隙摆动电弧GMAW技术和不同衬垫材料的应用,为ZG/NM组合的焊接提供了有益的试验结果,对焊接接头的性能和微观结构进行了深入分析,为相关领域的进一步研究提供了参考依据。

中部槽中板与槽帮自动组装设备设计

基于伺服电机驱动滚珠定位、位置传感器以及专用机械工装设计了中部槽中板与槽帮自动组装设备和自动传输机构。通过激光测距传感器测量槽帮端面位置并通过PLC控制定位气缸的实时调整,进而实现中部槽中板和槽帮的自动组装。最后通过非接触间接测量方式确定组装精度,自动下发检测结果。结合中板与槽帮的自动组装、检测形成闭环控制,提高中部槽制造的智能化水平。

不同工况下刮板输送机中部槽的磨损性能分析

刮板输送机是进行煤炭开采输送的重要设备,其中部槽在长期的使用中容易造成颗粒磨损。针对煤炭颗粒对中部槽的磨损作用进行离散元仿真分析,在不同的速度及粒度工况下分析中部槽的磨损规律,从而为刮板输送机的设计使用提供参考。

基于Ansys的刮板输送机中间槽中板耐磨性优化及应用

采用SolidWorks及Ansys软件搭建了刮板输送机中间槽结构的有限元模型,并分析其接触摩擦应力,结果表明,接触摩擦应力过大和分布不均匀是造成中间槽磨损的主要因素。通过对中间槽表面施加凹孔的形式对其进行结构优化,使得最大接触应力有所降低,应用效果表明,优化后的中间槽结构部署到SGZ型刮板输送机的工程实践中,可有效提升设备的最大运量。

矿用刮板输送机中部槽磨损性能研究

通过EDEM软件构建刮板输送机中部槽离散元模型,为刮板输送机中部槽磨损提高仿真分析方法支持。具体模型构建后分别从煤的物理性质和不同工况条件两个角度分析刮板输送机中部槽磨损影响因素。另外,将刮板输送机中部槽磨损模型仿真分析方法应用于工程实际,检验模型仿真方法应用价值。

可拆卸中部槽式转载机设计

目前,在煤矿综采面末采工作面到达停采线时,采煤机将不能继续开采,这样通常会留下一个巨大的煤柱,该煤柱长度与各输送设备机头、机尾长度有直接关系,造成资源浪费。设计一种中部槽可拆卸的转载机,该转载机中部槽为开式结构,可根据开采进度在不拆除链条的情况下方便地拆卸中部槽,缩短有效长度,可将之前无法开采的煤柱厚度降低到最小,节约资源,提高企业经济效益。

刮板输送机中部槽粗糙表面接触滑动力学分析

以SGB420/30刮板输送机为例,介绍一种基于刮板输送机中部槽粗糙表面接触滑动力学的分析方法。首先,将中部槽相关参数添加到ABAQUS软件内,由该软件自动构建出刮板输送机中部槽有限元模型,进而以此为基础,分别模拟分析了中部槽表面接触面积、粗糙表面接触压力及粗糙实体应力场分布情况,确定出中部槽易出现疲劳磨损的区域,从而为整个中部槽结构的优化设计提供支持。

刮板输送机中部槽粗糙表面接触滑动力学分析

以SGB420/30刮板输送机为例,介绍一种基于刮板输送机中部槽粗糙表面接触滑动力学的分析方法。将中部槽相关参数添加到ABAQUS软件内,由该软件自动构建出刮板输送机中部槽有限元模型,进而以此为基础,分别模拟分析了中部槽表面接触面积、粗糙表面接触压力及粗糙实体应力场分布情况,确定出中部槽易出现疲劳磨损的区域,从而为整个中部槽结构的优化设计提供支持。

刮板输送机配套参数对采煤机装煤效率的影响

采煤机滚筒在开采中起截煤与装煤的作用,随着对采煤机功率的深入研究,目前采煤机滚筒的截煤能力已基本满足要求,但装煤效率方面还存在很多问题,中厚煤层方面装煤效率的研究更是少之又少。基于离散元理论,结合颗粒位移方式以及颗粒间接触本构建立了中厚煤层双滚筒采煤机仿真模型,通过模拟计算出采煤机刮板输送机挡煤板高度、中部槽宽度、中部槽与煤壁水平距离等因素对装煤效率的影响曲线,并进一步分析其影响原因,为今后双滚筒采煤机装煤效率的改进与研究奠定了基础。

全熔敷中部槽的研究及应用

中部槽作为刮板输送机的关键部件,其平稳运行是保证高产、高效煤炭开采的重要因素。为解决中部槽因磨损失效造成使用寿命短的问题,采用熔敷技术对磨损的中部槽进行耐磨强化处理。通过井下工业性试验验证了方案的可行性和有效性,能显著提高中部槽耐磨性能,有效延长其使用寿命。

刮板输送机槽帮磨损问题分析与改进

针对刮板输送机槽帮上沿磨损严重的问题,运用EDEM有限元仿真分析软件,开展了槽帮由空载到满载运行过程受力情况的分析。结果显示,随着落煤量的增加,槽帮最大应力位置逐渐由槽帮下沿转移至上沿,满载稳定运行时槽帮上沿受力大于槽帮下沿,是导致槽帮上沿严重磨损的原因。通过改进槽帮内侧曲线的方法进行结构改进,结果表明,改进槽帮结构受力分布情况与改进之前一致,相同时刻的最大应力均得到了降低。试验验证结果表明,改进槽帮结构相同运行时刻上沿实际磨损量均得到了降低,取得了较好的改进效果。

Paleoproductivity variations in the southern Okinawa Trough since the middle Holocene:Calcareous nannofossil records

Based on 17 AMS 14 C age data,we reconstructed high-resolution records of sea surface primary productivity(PP) in the southern Okinawa Trough(MD05-2908) over the last 6.8 ka BP using the calcareous nannofossil carbon isotope and the relative percentage contents of Florisphaera profunda indexes.The underlying mechanism controlling the sea surface PP was then discussed.The sea surface PP,indicated by the coccolith δ 13 C and %Fp conversional equations,decreased with some fluctuations since 6.8 ka BP.This decrease may be connected to the decreased terrigenous input resulting from the reduced East Asian Summer Monsoon(EASM) precipitation.Both the periods of 4-2 ka BP(PME) and 6.8-4.8 ka BP were characterized by relatively higher PP.The former was mainly controlled by the weakening of the Kuroshio Current,whereas the latter mainly resulted from the greater terrigenous input associated with the stronger EASM.

Existing states of copper in the hydrothermal activity area of the Middle Okinawa Trough

THERE are four submarine hydrothermal activity areas in the Middle Okinawa Trough. They are Izena hole(127°05’E, 27°16’N), Iheya Deep (126°58’E, 27°33’N). Natsushima 84-1 Mound (127°08.6’E, 27°34.4’N), Western mount of Tokunoshima island (127°39’E, 37°52’N), respectively. In an attemptto determine the influence of the Middle Okinawa Trough area hydrothermal activity on copper distributionin the surrounding sediments, 8 surface samples and 6 core samples collected from this area were analyzedfor sequential extraction procedure and bulk analyses. 1 Samples and method Sediment samples were collected at 8 stations by dredger or piston corer (table 1). The sampleswere stored at【4℃, dried at【110℃, and finely ground to pass 200 meshes in an agate mortar.Sequential leaching procedures developed by Tessler were modified as follows: Cu (1) was ex-

冲绳海槽中部和南部玄武岩的区域性差异及其成因研究

本文从岩石学和岩石化学角度出发 ,对冲绳海槽中部和南部玄武岩样品进行了对比研究。结果表明中部和南部玄武岩均系亚碱性玄武岩 ,其中前者兼具钙碱性系列和拉斑玄武岩系列两种性质 ,后者则主要属拉斑玄武岩系列。根据岩石化学特征命名 ,中部样品主体为石英拉斑玄武岩 ,南部样品则为橄榄拉斑玄武岩。两区海槽玄武岩岩浆均由下伏地幔岩部分熔融而成 ,但源区地幔性质不均一 ,岩浆演化程度各异。中部样品源区地幔性质为过渡型 ,结晶分异程度较高 ;南部样品源于近亏损或富集型的地幔 ,结晶分异程度较弱 ;另外两区玄武岩样品均受到了不同程度的陆壳物质混染。中、南部海槽玄武岩在岩石学、岩石化学方面的差异与源区地幔性质不均一和岩浆演化程度各异有直接关系。海槽玄武岩构造环境属于过渡洋中脊玄武岩 (张性 )与岛弧玄武岩 (压性 )之间 ,代表的仍是海槽早期的岩浆活动。

中国中寒武世岩相古地理

本文是《中国早寒武世岩相古地理》的继续。本文的基础是笔者等的华北地区、华南地区和西北地区寒武纪和奥陶纪定量岩相古地理研究及编图的成果。定量 ,即每个古地理单元的划分都有确切的定量资料和定量图件为依据。在此基础上 ,结合其他地区的地质资料 ,主要是蒙兴地区、西藏地区、海南岛地区和台湾地区的地质资料 ,全面分析 ,综合判断 ,编制出了中国中寒武世岩相古地理图并撰写出本文。因此 ,在本文中 ,华北、华南和西北地区的岩相古地理图及其文字论述是定量的和比较精细的 ,其他地区的图件和论述则是定性的和概略性的。在中国中寒武世 ,早寒武世的“两槽和三台相间分布”的古地理格局仍未改变。两槽即天山北山蒙辽吉槽地和昆仑秦岭槽地 ,三台即准噶尔蒙兴台地、塔里木柴达木华北台地和西藏华南台地。这 5个古地理单元的范围与早寒武世的基本相同 。

中国中奥陶世岩相古地理

本文是中国早、中、晚寒武世和早奥陶世岩相古地理诸文的继续。在笔者等的华北地区、华南地区和西北地区寒武纪和奥陶纪定量岩相古地理研究及编图成果的基础上 ,结合其他地区 (主要是蒙兴地区、昆仑秦岭地区、西藏地区、海南岛地区和台湾地区 )的地质资料 ,编制出了中国中奥陶世岩相古地理图 ,并撰写出本文。华北地区、华南地区和西北地区的研究程度较高 ,其岩相古地理图和文字论述都是定量的。其他地区的研究程度较低 ,其岩相古地理图和文字论述则是定性的和概略性的。中国中奥陶世岩相古地理的基本格局仍和寒武纪及早奥陶世的一样为“两槽和三台相间分布”。两槽即天山北山蒙辽吉槽地和昆仑秦岭槽地 ,三台即准噶尔蒙兴台地、塔里木柴达木华北台地和西藏华南台地。但是这些古地理单元及其次级古地理单元的特征却和寒武纪及早奥陶世的有所不同或大不相同。