Discovery of Trace Fossils from the Sinian-Cambrian Boundary Beds in Eastern Yunnan and Their Significance for Global Correlation

There are abundant and highly varied trace fossils in the Sinian-Cambrian boundary beds in eastern Yunnan. Collections from 27 sections and their study give altogether 45 ichnogenera and 87 ichnospecies. Among them, 2 ichnogenera and 7 ichnospecies are new, and 31 known ichnogenera and 38 known ichnospecies first found in the region. According to their order of appearance in the boundary beds and their assemblage features, the trace fossils in the Sinian-Cambrian boundary beds in the region may fall into 4 trace fossil assemblage zones in ascending order. In the paper they are correlated with those in the equivalent horizons abroad and their geological significance is discussed preliminarily.

Concept of Bed Roughness Boundary Layer and Its Application to Bed Load Transport in Flow with Non-Submerged Vegetation

Ecosystem conservation has become one of the purposes in river management as well as flood mitigation and water resources management, and understanding of river flow and morphology in a stream with vegetation becomes important. Recently 2D depth averaged analysis is familiar even in a stream with vegetation by taking account of form drag due to vegetation. However, the shear stress in vegetated area is not properly described because the resistance law due to bed roughness is not reasonably modified in vegetated area. In this study, we discussed the bed roughness boundary layer in flow with non-submerged vegetation to deduce a reasonable relation between U and u* in vegetated area toward improving the analysis of sediment transport. The results show that the modification of resistance law using by thickness, velocity distribution in that layer was found to bring significant improvement of accurate estimation of shear velocity and subsequently the sediment transport. The proposed modification is improved by 2D depth averaged analysis based on this concept, and its application is certificated through flume experiment.

Comparing two IBM implementations for the simulation of uniform packed beds

Nowadays,the design of fixed packed bed reactors still relies on empirical correlations,which,especially for small tube to particle diameter ratios,are mostly too inaccurate because of the presence of wall effects.Therefore,the simulation of fixed packed bed reactors plays an important role to predict and control the flow and process parameters in such,nowadays and in the future.Because of its straightforward applicability to non-uniform packings with particles of arbitrary shapes,the immersed boundary method(IBM)has advantages over other numerical methods and is used more and more frequently.This paper compares two approaches of IBMs for the simulation of fixed bed reactors with spherical shaped particles.The classic,smooth approach is compared to the straightforward to implement blocked-off method for velocity fields above the fixed bed for particle Reynolds numbers of 300 and 500.Results from experimental inline PIV-measurements of the reactor to be simulated serve as a basis for comparison.Very good agreement with the experiment is found for both simulation methodologies with higher resolutions,considering the more stable flow at a particle Reynolds number of 300.Differences in the different IBM approaches occurred for the more unsteady flow at a particle Reynolds number of 500.Compared to the blocked-off method,the smooth IBM reflects the formation of additional jets and recirculation zones better right above the bed,though increasing the fluid mesh resolution improves the accuracy of the blocked-off method.Overall,a more diffusive behaviour is found for the blocked-off simulations due to the stairstep representation,which is avoided by using interpolation stencils as in the smooth IBM.With higher mesh refinement in the blocked-off IBM this effect can be reduced,but this also increases the computational effort.

Experimental and numerical investigation to elucidate the fluid flow through packed beds with structured particle packings

The present paper presents an experimental and numerical investigation of the dispersion of the gaseous jet flow and co-flow for the simple unit cell(SUC)and body-centred cubic(BCC)configuration of particles in packed beds.The experimental setup is built in such a way that suitable and simplified boundary conditions are imposed for the corresponding numerical framework,so the simulations can be done under very similar conditions as the experiments.Accordingly,a porous plate is used for the co-flow to achieve the uniform velocity and the fully developed flow is ensured for the jet flow.The SUC and BCC particle beds consist of 3D-printed spheres,and the non-isotropy near the walls is mostly eliminated by placing half-spheres at the channel walls.The flow velocities are analysed directly at the exit of the particle bed for both beds over 36 pores for the SUC configuration and 60 pores for the BCC configuration,for particle Reynolds numbers of 200,300,and 400.Stereo particle image velocimetry is experimentally arranged in such a way that the velocities over the entire region at the exit of the packed bed are obtained instantaneously.The numerical method consists of a state-of-the-art immersed boundary method with adaptive mesh refinement.The paper presents the pore jet structure and velocity field exiting from each pore for the SUC and BCC packed particle beds.The numerical and experimental studies show a good agreement for the SUC configuration for all flow velocities.For the BCC configuration,some differences can be observed in the pore jet flow structure between the simulations and the experiments,but the general flow velocity distribution shows a good overall agreement.The axial velocity is generally higher for the pores located near the centre of the packed bed than for the pores near the wall.In addition,the axial velocities are observed to increase near the peripheral pores of the packed bed.This behaviour is predominant for the BCC configuration as compared to the SUC configuration.The velocities near the peripheral pores can become even higher than those at the central pores for the BCC configuration.It is shown that both the experiments as well as the simulations can be used to study the complex fluid structures inside a packed bed reactor.

Age Assignment of the Lycoptera- bearing Bed

In the Yanliao area, the occurrence of the Nestoria-Keratestheria fauna and the Eoparacypris- Luanpingella-Darwinula assemblage in the Dabeigou Formation s.s., a Rb-Sr isochron age of 145.2 Ma for the Baiqi Formation and a complete stratigraphic sequence-all this proves that the Lycoptera-bearing bed overlies the Upper Jurassic. The Jehol fauna comprises the primitive Trigonioidids fauna, Eosestheria fauna, Lycoptera fauna et al., and their own laws of evolution expound that they belong to Cretaceous faunas. The associations of Eosestheria with Yanjiestheria, Lycoptera with Eosestheria, and Kuntulunia with Yanjiestheria as well as the occurrence of early angiosperms and sporo - pollen in the Fuxin Formation and its equivalents also demonstrate that the Lycoptera-bearing, bed should be assigned to the Cretaceous. The confirmation of the existence of Aucellina in the Jixi Group and the correlation of Trigonioidids and Cypridids with those in the equivalent strata of Japan and Western Europe have also been verified by corresponding marine strata. According to the magnetostratigraphic data from Zhejiang and Songliao, it has been preliminarily ascertained that M0 between the mixed polarity zone in the lower part and the normal polarity zone in the middle part of the Cretaceous is located in the upper member of the Huangjian Formation of the Jiande Group and the top member of the Denglouku Formation of the same group, and the isotopic age data of the Jehol and Jiande Groups show that the approximate geologic age of the Lycoptera bed is 135-122 Ma. These prove that the Lycoptera bed should be assigned to the Cretaceous.

Estimation of Bed Shear Stresses in the Pearl River Estuary

Mean and fluctuating velocities were measured by use of a pulse coherent acoustic Doppler profiler （PC-ADP） and an acoustic Doppler velocimeter in the tidal bottom boundary layer of the Pearl River Estuary. The bed shear stresses were estimated by four different methods： log profile （LP）, eddy correlation （EC）, turbulent kinetic energy （TKE）, and inertial dissipation （ID）. The results show that （a） all four methods for estimating bed stresses have advantages and disadvantages, and they should be applied simultaneously to obtain reliable frictional velocity and to identify potential sources of errors; （b） the LP method was found to be the most suitable to estimate the bed stresses in non-stratified, quasi-steady, and homogeneous flows; and （c） in the estuary where the semi-diurnal tidal current is dominant, bed shear stresses exhibit a strong quarter-diurnal variation.

Ammonoid Succession of Setorym River (Verkhoyansk Area) and Problem of Permian-Triassic Boundary in Boreal Realm

The presence of a single Otoceras species ( O. boreale ), morphologically very variable, at the base of the Nekuchan Formation in Verkhoyansk, we believe, is to be obvious. Some morphological evidence leaves no doubt that two described morphs of O. boreale are a strictly corresponding sexual dimorphic pair. It is very likely that Kummel's idea that Canadian O. concavum Tozer is an invalid species is truthful, considering the range of variability seen in larger Siberian and Himalayan Otoceras fauna. Just above the upper Tatarian Imtachan Formation, the six stages of ammonoid succession can be recognized within the lower part of the Nekuchan Formation in the Setorym River Section: (a) Otoceras boreale ; (b) Otoceras boreale-Tompophiceras pascoei ; (c) Otoceras boreale-Tompophiceras pascoei- Aldanoceras ; (d) Tompophiceras pascoei-Otoceras boreale-Aldanoceras ; (e) Tompophiceras morpheous-T. pascoei-Aldanoceras ; (f) Tompophiceras morpheous-T. pascoei-Wordieoceras domokhotovi-Ophiceras transitorium; (g) Tompophiceras morpheous-T. pascoei, corresponding to the Otoceras boreale and Tompophiceras morpheous zones. In spite of the domination of Otocerataceae or Xenodiscaceae in both of these zones and the presence of some Permian type conodonts in the lower part of the Otoceras boreale Zone, they seem to be early Induan in age on the basis of the following arguments: (1) in contrast to the underlying regressive type sediments of the Upper Tatarian Imtachan Formation, both the Otoceras boreale and the Tompophiceras morpheous zones of the lowermost part of the Nekuchan Formation correspond to the single transgressive cycle; (2) typical early Induan ammonoids ( Ophiceras and Wordieoceras ) have been recognized in the Tompophiceras morpheous zone; (3) all described ammonoid succession stages (a-g) are characterized by very gradual changes and therefore correspond to the different parts of the single zone or to the different zones of the same stage, but not to the different systems (Permian and Triassic); (4) elsewhere in the Boreal realm (Arctic Canada), the conodont index species for the base of the Triassic, Hindeodus parvus , has been reported from the Otoceras boreale Zone. A new scheme of the phylogeny for the Otocerataceae and its Induan Olenekian offspring (Araxceratidae- Otoceratidae- Vavilovitidae n.fam.-Proptychitidae-Arctoceratidae) and Xenodiscaceae is offered.

Oxidation Kinetics of Aluminum Powders in a Gas Fluidized Bed Reactor in the Potential Application of Surge Arresting Materials

In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general.

基于Python的断面解释图目标层埋深数据提取程序开发

在电法勘探项目中,目标层埋深图是主要提交成果之一。这里结合反演电阻率推断解释断面图中常见的地质情况,分析总结了不同地质情况下的目标层埋深数据提取方式,并提出了圈定埋深数据边界的算法。利用Python语言及其第三方库的强大计算和绘图功能,实现了埋深数据的提取及其边界的圈定,为下一步数据成图提供借鉴。实践结果表明,该程序能有效地结合不同地质情况,借助图形进行交互操作,能快速、准确地提取目标层埋深数据,具有较强的实用性。

河道推移质最大输沙能力影响因素敏感性分析

河道推移质最大输沙能力受到水动力和河道边界多因素的共同影响。采用水力半径分割方法,以河岸坡角为θ的等腰梯形为过水断面,λ为河岸与河底的相对糙率,d50为床沙中值粒径,nb为河底糙率系数,Q为流量,S为比降,利用变分方法解析各因子对河道的推移质最大输沙能力和相应最优河道形态的影响程度。结果表明:河道推移质最大输沙率随着λ的增大而增大,随着θ的增大而减小,即河岸糙率的相对增大或河岸坡度的减小都会提升最大输沙能力;流量Q、比降S的增大,均可提升最大输沙能力;河底糙率系数nb减小、流量维持不变将会降低最大输沙能力,床沙中值粒径d50减小则会提升最大输沙能力;既不特别宽浅又不特别窄深的河道具有最大的推移质输沙能力。

Evaluation of the effect of wall boundary conditions on numerical simulations of circulating fluidized beds

A computational fluid dynamics （CFD） modeling of the gas-solids two-phase flow in a circulating fluidized bed （CFB） riser is carried out. The Eularian-Eularian method with the kinetic theory of granular flow is used to solve the gas-solids two-phase flow in the CFB riser. The wall boundary condition of the riser is defined based on the Johnson and Jackson wall boundary theory （Johnson ＆ Jackson, 1987） with specularity coefficient and particle-wall restitution coefficient.The numerical results show that these two coefficients in the wall boundary condition play a major role in the predicted solids lateral velocity, which affects the solid particle distribution in the CFB riser. And the effect of each of the two coefficients on the solids distribution also depends on the other one. The generality of the CFD model is further validated under different operatin~ conditions of the CFB riser.

A note on a boundary condition for spouted beds

The boundary condition, zero solids pressure at the top of a particle bed of maximum spoutable height, Hm, is shown to eliminate any resort to empiricism in the derivation of the fluid velocity in the annulus of a spouted bed for which both viscous and inertial effects are taken into account. The same boundary condition fails when applied to a spouted bed for which the bed height H 〈 Hm, especially when H 〈 0.8Hm.

相干技术的参数选取及其效果分析

孙义梅 ,杨春峰 ,陈程 ,贾曙光 ,田世澄 .相干技术的参数选取及其效果分析 .石油地球物理勘探 ,2 0 0 1,36 (5 ) :6 4 0～ 6 4 5相干技术是对地震道间的波形相似性进行分析 ,它采用水平或平面图的方式显示具不连续性特征的断层和地层边界。本文从相干技术原理出发 ,重点讨论其参数选取和技术特征。相干数据处理中的两个主要参数是相干道数和相干时窗 ,作地层边界处理时 ,分别选用 3道、5 0 ms;作断层特征处理时 ,选用 9道、5 0 ms。将相干分析技术与常规时间振幅切片、瞬时相位切片、边界检测等技术相比 ,发现前者在解释断层。

江西二叠－三叠系界线

本文描述了江西省北部、中部、南部地区二叠－三叠系界线剖面各１条，对每条剖面进行沉积相分析，从生物地层学角度论证其界线存在的可靠性。Ｈｉｎｄｅｏｄｕｓｐａｒｖｕｓ在江西修水清水岩乡东岭的发现是中国的又一新发现地区。二叠－三叠纪生物地层界线以Ｈ．ｐａｒｖｕｓＭｏｒｐｈｏｔｙｐｅ１的首次出现为难；“界线粘土”层的底界属二叠－三叠系事件地层界线，与生物地层界线不是一回事，生物地层界线比事件地层界线在江西约高出１６─２０ｃｍ；建议在二叠－三叠系界线研究中，最好不用“混生层”或“过渡层”，而改为界线地层或界线层。

扬子台区二叠-三叠系界线层综合地层学研究

华南二叠－三叠系界线研究一直在地学界备受瞩目．目前被广泛接受的界线标准化石为牙形石Ｈｉｎｄｅｏｄｕｓｐａｒｖｕｓ，该化石的首现位置被定义为二叠－三叠系界线层型剖面点．然而在全球研究精度最高的４个候选层型剖面中，生物地层单位的对比问题尚存在分歧，从而影响了区域高精度地层对比框架的建立．在扬子台区丰富的资料及大量二叠－三叠系界线剖面进一步研究的基础上，发现许多剖面上二叠－三叠系界线处具有相似的岩石地层特征．其基本结构为粘土岩层、灰岩或泥灰岩层及粘土岩层沉积组合．从综合地层学角度的研究表明：该套沉积组合（界线层）在岩性特征、生物群总体面貌以及其他事件标志（如同位素年龄、磁性地层、地球化学特征等）上具有一定的对比意义．认为界线层应该是等时的地层单位，是扬子台区二叠－三叠系界线处重要的标志层组，并对这套地层进行了区域性对比．这套地层的发现大大提高了扬子台区二叠－三叠系界线处地层的对比精度．

大斜度井/水平井随钻方位电磁波测井资料实时反演方法

水平井钻进过程中,地层边界的准确预测对地质导向决策至关重要.但水平井测井环境复杂,随钻方位电磁波测井响应不直观,储层性质、地层界面等信息的精确、定量评价困难.本文提出了一种适用于大斜度井/水平井随钻方位电磁波测井资料的电阻率及地层界面信息的实时提取方法.该方法主要基于以下几个技术:(1)引入滑动开窗策略将高维随钻方位电磁波测井资料的反演问题转化为多个连续窗口的一维反演问题;(2)对反演参数进行多初值初始化,结合正则化Levenberg-Marquardt算法保证解的全局最优性;(3)充分利用随钻方位电磁波测井多种探测深度信息,采用分级反演策略提高反演速度.数值和实测资料反演结果表明:降维反演方法可实现对地层界面的实时、准确提取,且适用于多数复杂地层结构和任意井眼轨迹;利用浅探测地质信号可实现随钻方位电磁波测井资料的分级反演,最终反演速度可提升10倍以上.

松辽盆地南部上白垩统中部组合层序界面的识别标志及高分辨率层序地层格架

系统总结了松辽盆地南部中部组合层序界面的岩心、测井、生物、地震等识别方法;统计了盆地短轴方向不同相带层序界面及短期基准面旋回的分布特征,并分析了层序界面和短期旋回模式在不同相带的分布规律。中部组合青山口组和姚家组共划分为4个长期旋回和10个中期旋回。在层序地层序、沉积学原理的指导下,采用岩心、测井、地震三位一体,点、线、面紧密结合,以岩心、测井层序划分为基础,以地震技术为手段进行层序地层的立体拓展,建立层序地层格架,为下一步勘探提供了重要的依据。

随钻方位电磁波测井反演模型选取及适用性

随钻方位电磁波测井可提供邻近地层界面的准确位置信息而被广泛运用于实时地质导向钻井,但如何选取合适的反演模型和最优化算法则是决定随钻方位电磁波测井资料反演速度和精度的关键。为此,首先基于降维策略将复杂地层随钻方位电磁波测井资料3D反演问题简化为一系列1D问题,然后探讨不同1D反演模型、反演算法的可行性与反演效果,并给出了两者组合的最优选取方法。数值模拟结果表明,1D反演模型的选取取决于靶层的厚度,而反演算法的选取则依赖于反演模型的层数,即对靶层厚度为4.0 m以上的厚层,应选用单界面反演模型和梯度反演算法组合;当靶层厚度为1.0~4.0m时,仅需将单界面反演模型替换为双界面反演模型即可提供准确的邻近上、下地层界面;对薄层随钻方位电磁波资料,则需采用多界面反演模型和Bayesian反演算法。

地层倾角测井沉积构造与层序界面识别

采用相关对比法对关键井的地层倾角测井资料进行处理,结合地质构造图反映出的构造倾向,确定倾角资料长相关处理参数;结合岩芯照片对倾角资料进行微细处理,确定短相关处理参数。利用确定的长、短相关处理参数,对哈得逊地区的倾角测井资料进行处理,建立了东河砂岩储层典型的层理和微构造倾角解释模型;对中泥岩段开展了层序地层研究,根据长窗长倾角矢量图和累积倾角图,在中泥岩段识别出1个完整的三级层序、2个准层序组和5个准层序;利用短窗长处理的倾角矢量图,结合原始电导率曲线和倾角测井解释结果,进一步识别出中泥岩段有7个岩层组和16个岩层。