贵州晚三叠世关岭鱼龙的原始尾弯对比研究

通过对贵州关岭上三叠统卡尼阶法郎组瓦窑段地层中的两件关岭鱼龙属标本的观察、测量,并与早侏罗世鱼龙标本对比研究,发现晚三叠世的关岭鱼龙尾椎中部存在一定数量形态发生变化的侧视呈梯形的椎体,已经具有了传统观点认为只在侏罗纪和白垩纪鱼龙中出现的尾弯,弯角为15°左右(侏罗纪鱼龙尾弯弯角可达60°)。这一衍生性状的出现表明晚三叠世关岭鱼龙已经在一定程度上具有了鼎盛时期鱼龙所拥有的尾鳍,并已获得了较强的游泳能力,开始成为完全适应远洋快速游泳的生物,并将以前认为截然分离的三叠纪的早期鱼龙类群与侏罗纪-白垩纪鼎盛时期特化的鱼龙类群联系起来,是鱼龙目单系起源的又一例证。     

贵州龙脊椎动物群研究新进展

贵州龙动物群是一个分布范围广泛、时代延续较长、内容丰富的三叠纪海生脊椎动物群.对它的研究可以完善人们对海生脊椎动物各门类的起源、分布、系统发育和古生物地理的认识.近期的研究表明,贵州龙动物群中包括目前世界上所发现的所有三叠纪海生爬行类的主要类群--鳍龙类、鱼龙类、海龙类和原龙类.它由早三叠世晚期至晚三叠世早期的6个脊椎动物组合组成.它们是嘉陵江组的湖北鳄-贵州龙-裂齿鱼组合、关岭组一段的清镇龙-三桥龙组合、关岭组二段的原龙类-鱼龙类鱼类组合、杨柳井组的鱼龙类和一位置未定的爬行类组合、法郎组竹杆坡段的贵州龙-幻龙-中华真颚鱼组合和法郎组瓦窑段的安顺龙-黔鱼龙-中国豆齿龙组合.贵州龙动物群的成员分别与同时代西特提斯区及东太平洋区动物群的成员关系密切.     

贵州关岭晚三叠世邓氏贵州鱼龙（Guizlwuichthyosaurus tangae Cao and Luo in Yin et a1．，2000）的讨论

贵州省关岭县新铺地区晚三叠世法郎组瓦窑段下部的鱼龙标本保存完整、精美，对它们准确而详细的描述将对研究鱼龙类分类、演化和完善其演化谱系具有重要的意义。目前对其中大型鱼龙已有Guizhouichthyosaurus tangae、Typicusichthyosaurus tsaihuae、Guanlingsaurus liangae、Cymbospondylus asiaticus、Panjiangsaurus epicharis等5个命名。在野外调查、室内修理、观察、比较的基础上，补充、修正了Guizhouichthyosaurus tangae的描述，并认为Cymbospondylus asiaticus和Panjiangsaurus epicharis应为Guizhouichthyosaurus tangae的同物异名。     

贵州关岭晚三叠世邓氏贵州鱼龙（Guizhouichthyosaurus tangae Cao and Luo in Yin et al., 2000）的讨论

贵州省关岭县新铺地区晚三叠世法郎组瓦窑段下部的鱼龙标本保存完整、精美,对它们准确而详细的描述将对研究鱼龙类分类、演化和完善其演化谱系具有重要的意义。目前对其中大型鱼龙已有Guizhouichthyosaurus tangae、Typicusichthyosaurus tsaihuae、Guanlingsaurus liangae、Cymbospondylus asiaticus、Panjiangsaurus epicharis等5个命名。在野外调查、室内修理、观察、比较的基础上,补充、修正了Guizhouichthyosaurus tangae的描述,并认为Cymbospondylus asiaticus和Panjiangsaurus epicharis应为Guizhouichthyosaurus tangae的同物异名。     

安徽巢湖早三叠世原始鱼龙类的结构和行为特征及其对鱼龙类起源研究的启示

鱼龙类(Ichthyosaurs)起源于早三叠世晚期, 以往发现的鱼龙类已高度适应水生生活, 其身体结构无任何能将其与可能的陆地祖先相联系的陆生适应特征。针对近年在安徽巢湖下三叠统奥伦尼克阶采集的柔腕短吻龙(Cartorhynchus)和含胚胎巢湖龙两件鱼龙类标本, 通过对柔腕短吻龙的荐前椎数目(31节)、吻长与头骨长之比(0.35)、前肢长与荐前椎长之比(0.45)的研究以及与后期鱼龙类相关数据和骨骼形态学的对比, 认为柔腕短吻龙结构更为原始, 可两栖生活。结合对早三叠世含胚胎巢湖龙、侏罗纪含胚胎狭翼鱼龙幼体保存情况的对比分析, 认为巢湖龙虽比柔腕短吻龙身体结构更进化, 且完全适应水生生活, 但其生殖行为仍然保持陆生爬行动物头位胎生的特征。鱼龙类在其陆地祖先逐渐演化至适应水生生活的过程中, 结构的适应性特征(如肢体的鳍状化、吻部的增长等)和行为特征(如生产方式的变化)的变化不同步, 前者的改变更早。     

地质王国风采录(三)——古生物化石聚集地之关岭

<正>卧龙岗上的传奇故事海生爬行动物的天堂与墓地贵州关岭化石群中外知名。由此而建立的关岭国家地质公园位于贵州省安顺市关岭县新铺镇。化石保护面积分布200平方千米、公园规划面积86平方千米。主景区在卧龙岗,面积0.94平方千米。2004年2月成为中国国家地质公园。关岭化石群国家地质公园埋藏的化石形成于距今两亿两千万年前晚三叠世浅水环境,主要化石门类包括:海生爬行动物(鱼龙、海龙、楯齿龙、龟等4大类)、海百合、菊石、双壳、鹦鹉螺、腕足类、鱼类软体动物6大类11种,和来自附近陆地的古     

贵州龙与恐龙

正贵州龙生活在三叠纪的海洋里,以小型水生动物为食;而绝大多数恐龙则生活在侏罗纪至白垩纪时期的陆地上,以植物和动物为食。到目前为止,我们尚未发现古生代的海生爬行类化石。但几乎所有的海生爬行类—鳍龙类、海龙类、鱼龙类等都相继在早三叠世到中三叠世初的海洋中出现了,并在中三叠世达到辐射发展的顶峰,大部分类群在晚三     

安徽早三叠世巢湖龙前肢比较及分类学意义

由于标本少和保存情况不好等原因, 对巢湖龙(Chaohusaurus)解剖学特征缺少详细描述, 安徽地区巢湖龙的种级分异尚存争议。经过对比研究北京大学地质博物馆馆藏的采自安徽巢湖的鱼龙标本与相关模式标本, 基于骨骼形态及腕骨骨化程度等方面的差异, 将标本分为两类。将研究标本及相关模式标本等进行聚类分析, 结果表明存在两个类群。将前肢骨骼数据作图, 显示存在两条生长序列, 该结果推翻了之前的巢县陈氏龙和小巧陈氏龙均为龟山巢湖龙后出同物异名的结论。据此推断, 巢湖马家山地区的巢湖龙可能存在两个物种。厘清巢湖龙的种间关系有助于全球早三叠世原始鱼龙类的对比研究, 并对探讨鱼龙的早期演化具有十分重要的意义。     

贵州晚三叠世关岭生物群集群死亡事件探秘

关岭布依族苗族自治县位,贵州省西南部,隶属于安顺市,境内山脉属于乌蒙山系,山体起伏绵延。这里的碳酸盐岩分布广泛,岩溶地貌千姿百态。就在这片崇山峻岭中,蕴藏着一个精美且具有重要科学意义的古生物化石群一关岭生物群。它包含了晚三叠世（2亿2千万年前）的许多重要生物,如个体巨大的鱼龙和海龙等海生爬行动物,密密匝匝倒悬在海洋中浮木上的海百合,以及大量的双壳类、腕足类和菊石类等无脊椎动物。     

贵州中三叠世盘县动物群比耶鱼属未定种的发现及其意义

记述采集自贵州省盘县中三叠统安尼阶关岭组上段盘县动物群的一件仅残存尾部的比耶鱼标本。这是比耶鱼在该动物群的首次报道, 也是目前比耶鱼在中国地质时代最早的化石记录。依据标本个体大、仅尾上叶及尾柄后缘背侧覆盖有狭长条状且缺失硬鳞质的鳞片、尾部发育单个愈合的神经棘和脉棘、尾鳍背缘棘鳞发育等特征, 将其归入比耶鱼属。同时, 该标本以个体更大(推测身长超过2 m)、尾下骨更多(9 根)、尾下叶棘鳞发育以及上、下叶外缘交角超过 70°等特征, 不同于已报道的其他比耶鱼物种。但是, 考虑到标本信息有限, 暂定为比耶鱼未定种Birgeria sp.。比耶鱼是仅见于三叠纪海洋中的全球性分布的大型肉食鱼类, 其在盘县动物群中的首次发现丰富了该动物群鱼类多样性, 增加了其群落生态结构的复杂性。基于当前化石发现的情况, 认为比耶鱼在东特提斯生物区(中国)较西特提斯生物区的出现可能更晚, 前者最早的化石记录见于中三叠世安尼期, 而后者最早见于早三叠世史密斯亚期。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.