超临界水密度和自扩散系数预测的分子动力学模拟

采用分子动力学方法模拟了温度范围为673.15～873.15 K,压力范围为22.1～131.3 MPa条件下不同状态点水的密度和自扩散系数,并与实验结果进行对比.模拟体系为256个水分子,模拟系综为等温等压系综.模拟结果表明:密度和自扩散系数的模拟预测值与实验值基本一致;密度的模拟预测值大多低于实验值,最大相对误差小于-20 %;自扩散系数的模拟预测值大多高于实验值,但最大相对误差小于±20 %.在缺乏实验数据时,利用单点电荷 (SPC)势能模型,可采用分子动力学方法预测超临界水的密度和自扩散系数.     

基于蒙特卡罗方法的水扩散系数及其与温度的关系

使用蒙特卡罗方法,在计算机上模拟了水分子在水中的自扩散过程,进而估算了水的自扩散系数.通过对1标准大气压、不同温度条件下水的自扩散系数进行计算,并与相同条件下的实验值以及其他文献中的计算值进行对比,发现数值较为接近,说明模拟方法较为成功.同时,研究了模拟的自扩散系数与温度的关系,发现自扩散系数随温度升高而快速增加,与温度的倒数间成负指数关系,这与实验和理论结果符合得很好.     

温度和外加电场对水分子团簇影响的分子动力学模拟

应用分子动力学（MD）模拟方法研究了温度从273～373K，电场强度从0-2×10^10V／m时水分子团簇的热力学性质、微观结构和动力学性质．研究发现，内能与温度成正比与电场强度成反比，通过分析径向分布函数，我们得知，温度升高使水的氢键作用减小，外加电场增加使氢键作用增强，使水的有序程度加强．水的自扩散系数随温度升高而增大，随电场强度的增加而减小，且在低温时，有电场时水的自扩散系数是无电场时的十分之一．     

都柳江水体-沉积物间锑的迁移转化规律

锑(Sb)是近年来广泛受到关注的一种污染物,都柳江流域有较多的锑矿山分布,采集并分析了都柳江(贵州独山至广西富禄)水和沉积物样品,结果显示:河流的自净稀释作用使都柳江水体-沉积物中的Sb含量呈总体一致下降趋势,沉积物中Sb含量较高;沿途锑矿山溪水的加入显著增加了水体-沉积物中Sb的浓度.水体-沉积物中的Sb含量变化呈如下规律:上游至三都米英D10点,粘土矿物和铁氧化物的吸附作用较强,Sb从水体迁移到沉积物中;下游D7至采样终点,以粘土矿物的解吸作用为主,Sb从沉积物迁移到水体中,最终导致水体中Sb含量升高,进而对水生生态系统构成一定的威胁.     

生物柴油/柴油乙醇水微乳体系相行为分析

采用化学滴定方法研究了生物柴油/柴油乙醇水微乳体系的相行为;分析比较了生物柴油/柴油混合比改变对其相行为的影响。结果表明:在不添加任何乳化剂的条件下,稳态相图中存在一个各向同性的单相区,单相区内混合液为稳定、透明的生物柴油/柴油乙醇水微乳化油,表明生物柴油可作为有效的表面活性剂;单相区的面积大小与体系中各组分的含量有关。当乙醇含量及生物柴油与柴油的混合比增加时,单相区变宽;在乙醇含量一定时,形成稳定单相微乳化油的最大掺水量随体系中生物柴油的含量增加而增加。最后得到了不同乙醇含量及不同生物柴油与柴油混合比条件下形成生物柴油/柴油乙醇水微乳化油的最大掺水量。     

体相CO2约化自扩散系数的标度律关联模型

用巨正则转换矩阵蒙特卡罗（GC-TMMC）和分子动力学（MD）模拟方法研究了体相CO2单位分子的过剩熵与其约化自扩散系数（D*s）的标度关系。过剩熵主要考虑3种定义：总体过剩熵sex，以分子重心径向分布函数定义的二体熵s(2)c和所有原子径向分布函数定义的二体熵s(2)t。结果表明，总体过剩熵sex与D*s之间存在明显的标度关系，并且独立于状态点所处的相态，可以用热力学量-过剩熵来关联动力学量-自扩散系数（约化方式）；二体熵在小于超临界温度范围内的标度结果偏离了-sex-D*s的“共同曲线”。本文拓展了过剩熵标度律在分子流体中的应用范围，得到了其在体相CO2自扩散系数关联中的应用规律。     

复杂构造区不同岩相页岩油散失量研究——以准噶尔盆地博格达地区中二叠统芦草沟组为例

页岩油散失是叠合改造盆地页岩油资源评价中的薄弱环节。保存条件对页岩油散失的影响及散失量表征,对于复杂构造区的“残留”页岩油资源科学评价具有重要的现实意义。为此,以准噶尔盆地博格达地区中二叠统芦草沟组为例,基于大量露头和钻井样品薄片鉴定、Ｘ-射线衍射全岩矿物分析、场发射扫描电镜、有机碳含量TOC、岩石热解S1和氯仿沥青“A”抽提等测试数据,在岩相类型和保存评价单元划分的基础上,建立不同评价单元、不同岩相的有机质丰度与含油率关系模型,实现页岩油散失量的量化表征,为残留页岩油资源量科学评价奠定基础。结果表明：①博格达地区芦草沟组表现为陆源碎屑组分和碳酸盐组分混合沉积特点,发育基质型和夹层型2类10余种岩相类型,可划分出凹陷区、构造稳定区、冲断改造区和地表出露区4类保存评价单元;②保存条件、储集空间类型及孔隙结构控制了不同岩相岩石的含油性差异,随构造变形强度的增强,保存条件变差,岩石的含油性整体呈减小趋势,基质型岩相富含有机质,有机碳含量与可动烃含量呈幂函数关系,夹层型岩相以外来烃充注为主,有机碳含量与可动烃含量呈线性关系;③建立了不同保存评价单元基质型和夹层型页岩油保存系数相对权重量化赋值模型,实现了页岩油散失量的量化表征,为复杂构造区残留页岩油资源评价提供了一种新的思路方法。     

烟草叶片不同部位对低温响应的研究

选取栽培烟草K326为实验材料研究叶片不同部位的生理差异及其对低温响应的不同. 结果发现,冷胁迫前远侧脉区(middle lamina,ML)H2O2含量低于近侧脉区(edge lamina,EL),抗坏血酸(ascorbic acid,AsA)含量高于EL,过氧化氢酶(catalase, CAT)活性低于EL,表明烟草叶片ML和EL具有生理差异. 4 ℃处理烟草24 h后,ML中H2O2含量升高但仍低于EL,AsA含量没有明显变化,ML中CAT活性高于EL 48.39 %,推测低温处理后ML中CAT对H2O2的清除起主导作用.     

一道课本例题教学的探索

苏课版义务教育课程标准实验教科书九年级（下册）第一章3节《平行四边形、矩形、菱形、正方形的性质和判定》例4已知如图（1）正方形的对角线AC、BD相交于点O，正方形A’B’C’D’的顶点A，与点O重合，A，B，交BC于点E，A’D’交CD于点F，求证：OE=OF．     

泾河油田长8储层渗流特征研究

运用毛细管平衡法和岩心流动试验方法,详细表征了岩心启动压力梯度、油水单相渗流和水驱油效率等渗流规律。启动压力梯度试验结果表明泾河长8超低渗储层的可动用岩心渗透率下限为0.525 m D,可动用原油粘度上限为10.5 m Pa·s。油、水单相渗流曲线都表现出非线性特征,且随着渗透率的降低,渗流非线性特征越明显。在相同注入压力梯度下,模拟油的渗流能力随着流度的减小而逐渐降低。水驱油效率试验结果表明水驱油效率随着流度的降低而降低,水驱油效率与模拟油流度成幂指数关系,流度范围0.024~0.062 9 m D/m Pa·s为拐点区域。     

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.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.