热源对核废料处置库近场性状的影响

采用高放射性核废料处置库模型进行试验, 以核废料处置库近场的膨润土及岩石为研究对象, 建立轴对称模型. 选用适当的控制方程, 运用有限元软件Code-Bright对核废料处置库关闭后处置库近场的温度场、渗流场、应力场进行热-水-力(thermo-hydro-mechanical, THM)耦合的数值模拟. 通过比较不同初始热源, 得到了处置库关闭后近场膨润土及岩石内温度、液体饱和度、吸力及应力的变化规律. 结果表明, 初始热源较小时膨润土和岩石的性质更为稳定.     

缓冲材料参数对核废料处置库近场影响的二维有限元分析

以高放射性核废料地质处置的FEBEX原位试验作为数值计算模型,利用有限元软件Code-Bright,通过改变膨润土初始渗透系数、初始吸力和初始进气值,得到热-水-力(thermo-hydro-mechanical,THM)耦合作用下处置库关闭后缓冲层饱和度和吸力的变化规律,以及以上3个因素对这些性状影响的敏感程度,研究结果可为核废料处置库缓冲材料的选取提供参考.     

初始孔隙率对高放射性废物处置库缓冲材料性状的影响

采用高放射性核废料处置库(high-level radioactive nuclear waste repsitory, HLWR)模型试验,以核废料处置库近场的缓冲层GMZ01膨润土为研究对象,建立轴对称模型.采用有限元(finit element method, FEM)软件Code-Bright,考虑热-水-力(thermo-hydromechanical, THM)耦合作用,研究作为缓冲层的GMZ01膨润土在处置库关闭后,不同压实度(初始孔隙率)对处置库渗流场、应力、温度的影响,得到了不同初始孔隙率膨润土在处置库封闭运行后温度、饱和度、吸力、应力等性状随时间的变化.实验结果可为中国北山核废料处置库的规划、设计、可行性分析提供一定的参考.     

高放废物处置库缓冲回填材料热-水-力耦合研究进展

用于高放废物处置库中的缓冲回填材料,在处置库运行期间产生的热-水-力耦合作用下,其性状发生改变,这将对缓冲回填材料的防护性能产生重要影响,进而引发一系列安全稳定性问题。因此,关于缓冲回填材料热-水-力耦合研究愈来愈受到广泛关注。在总结和分析国内外有关膨润土热-水-力耦合作用研究的基础上,从温度场、应力场和变形场等方面对当前的研究成果进行了归纳和总结,在此基础上指出,基于室内试验及数值模拟研究成果,开展深层地下现场试验研究是该领域当前发展的重要趋势,相关研究可为处置库运行时热-水-力耦合行为预测及处置库的规划、设计及建造提供理论参考。     

地质系统THMC耦合随机模型研究

热-水-力-化(THMC)耦合作用是岩石流体力学与环境地质中的重要理论课题.设计用实验方法研究温度场-渗流场-应力场-化学场四场耦合效应中热传导系数、渗透率及岩体变形参数的空间变异性表征方法,及块裂岩体的非确定性耦合控制方程,试图建立热-水-力-化耦合作用的随机性数学模型及可视化数值模拟方法,为核废料地质处置安全性评价和地下水资源评价等提供科学的新方法.     

膨润土-砂混合物缓冲层径向热传导性

膨润土-砂混合物作为高放废物处置库缓冲材料,在核废料衰变热影响作用下,其稳定性及物理力学性能产生显著变化,这对缓冲回填材料的包封阻隔作用及处置库的安全运行产生重要影响。本研究采用自行设计的装置对按比例缩小后的不同干密度、含水率、掺砂率试样进行热传导模拟试验,并对试验过程进行热-力耦合数值模拟分析,得到了缓冲层温度、应力和应变的变化及分布情况。结果表明,增大试样干密度、含水率和掺砂率均可提高导热性,应力和应变也随之增大,且不同含水率试样产生的结果变化显著;缓冲层靠近热源的位置温度、应力和应变最大,且沿径向方向减小,初始时刻各值变化显著。     

高放核废物处置库T-M耦合数值模拟

考虑到地下工程受地应力、温度、水的相互影响,导致岩体力学性质的改变,采用ANSYS有限元分析软件,基于Mohr-Coulomb破坏准则,建立高放核废物处置库的数值模型,在此基础上进行热-力（TM）耦合二维数值模拟．研究了高放核废物处置库9种方案运行一百年的温度、应力、位移变化,通过对比分析,在满足安全、经济的基础上,选择最佳的处置库间距和深度,为核废物处置库的设计提供参考依据．     

岩体开挖损伤区的表征及热-流-力耦合模型：研究现状及展望

地下岩体工程的开挖必然在巷道周边形成了开挖损伤区．认清开挖损伤区的物理力学性质及其时空演化规律,对于工程稳定性和安全性评价及支护参数优化是至关重要的．针对能源深部战略储备和核废料深部地下处置等工程问题,近年来岩体开挖损伤区表征及其热-流-力（THM）耦合模型方面取得了较大的进展．文中对岩体开挖损伤区的表征方法及岩体多场耦合模型的研究现状进行了综述和归纳,对其中的一些关键和热点问题进行了分析,并对今后需要开展的研究工作提出了一些看法．     

核废料泥岩处置库围岩综述

随着社会与经济发展对能源需求的不断加大,与深部围岩有关的岩土工程问题越来越受到广泛关注,如地热资源开发、核废料处置及煤炭地下气化等工程。很多国家已经对核废料处置库围岩进行了大量研究,其中泥岩因导水率低和自封闭能力强而受到极大重视。本文现就核废料处置库围岩泥岩来探讨,阐述泥岩作为处置库围岩的基本特性以及工程特性,详细阐明了其优点与不足。着重介绍了我国泥岩处置库围岩研究进展。     

热-力耦合作用下花岗岩蠕变损伤模型

热-力耦合作用下的岩石蠕变行为对深部地下工程、高放射性废料处置工程影响显著。基于20～300℃下的花岗岩蠕变试验,分析温度对瞬时应变和蠕变应变速率的影响,由此认为温度对花岗岩瞬时弹性模量造成瞬时损伤并促进后续蠕变损伤过程,从而定义瞬时、蠕变热损伤变量。构建广义Kelvin热损伤模型和黏塑性热损伤元件,采用Heard指数型模型描述花岗岩稳态蠕变行为,串联后得到一个新的热-力耦合作用下的花岗岩蠕变损伤模型。给出模型参数求解方法,分析瞬时、蠕变热损伤变量变化规律,通过辨识三种花岗岩的蠕变试验数据,验证所建模型的合理性和适用性。研究成果为热-力耦合作用下花岗岩蠕变行为模拟及深部地下工程、高放射性废料处置工程长期稳定性研究提供一定参考。     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

<正>~~     

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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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