岩溶含水层饱和-非饱和流动与污染物运移数值模拟

岩溶含水层中的地下水是重要的可饮用水来源, 由于其复杂的水文地质特征, 采用数值模型分析和评价含水层中地下水环境极具挑战性。采用变饱和度流动方程描述含水层基质中的饱和-非饱和流动, 采用管道流方程描述岩溶管道中的层流及紊流流动, 基于流动解采用对流弥散方程分别描述基质与管道中的溶质迁移过程。根据相关实验数据以及MODFLOW-CFP程序的模拟结果对流动模拟的准确性进行验证, 并基于此开展了岩溶管道以及非饱和参数对地下水流动及污染物迁移影响的模拟。结果显示, 数值模型能很好地重现含水层中饱和区与非饱和区以及岩溶管道的地下水动态, 岩溶管道对含水层的渗流场产生了较大的影响。管道中快速流动的特性使得周围的水向其中汇集, 影响了局部流动场, 进而使得泄露的污染物质随水流进入管道, 快速向管道出口处(泉点)迁移, 突破曲线显示管道出口处的污染物浓度响应速度远快于基质中对应的位置, 非饱和参数对管道中污染物浓度的响应速率有着不同程度的影响。建立的模型完善了岩溶含水层中非饱和区地下水流动、污染物运移以及基质-管道流动与溶质运移耦合模拟等方面的工作, 加深了对岩溶含水层地下水动力学以及污染物迁移过程的认识, 对岩溶水文地质及地下水环境等方面具有重要意义。      

高密度电阻率法监测纳米胶体在多孔介质中运移的实验

利用高密度电阻率法监测纳米胶体在饱和多孔介质中的运移过程.对纳米胶体和保守性示踪剂在末端的电导率穿透曲线进行了比较.结果表明,纳米胶体与保守性示踪剂在多孔介质中的运移过程非常相似,均可用一维对流弥散方程进行拟合.通过对不同截面、不同电极间距、竖直方向的电阻穿透曲线的比较,说明利用高密度电阻率仪监测纳米胶体在多孔介质中的运移是可行的.无论是传统示踪剂还是纳米胶体,在同一截面上不同电极间距几个测点的穿透曲线非常相似,沿着水流向前推进的溶液锋面到达同一电极截面的时间非常接近,说明多孔介质是非常均质的.同时高密度电阻率法可以动态反映砂柱中纳米胶体运移的时空变化特征.     

岩溶多重介质地下水模拟技术及应用进展

由于岩溶发育的极不均匀性和岩溶含水介质的多重介质性等特征, 使得岩溶水系统的地下水运动规律呈现出复杂多变的特点, 在孔隙或微小裂隙含水介质中岩溶水满足达西流, 而在岩溶管道中可能出现非达西运动, 这给岩溶区地下水模拟带来了极大挑战。系统地梳理了岩溶水流和溶质运移模拟的主要方法, 总结了复杂岩溶多重介质系统地下水模拟技术的现状, 并结合我国南方岩溶和北方岩溶各自的特点, 提出岩溶水模型在实际应用中需要关注的要点。主要包括: 需加强野外调查和观测, 提高模型中对岩溶含水介质结构非均质性表征的精度; 进一步深化对岩溶水运动机理的研究, 刻画岩溶多重介质的水流特征以及水交换机理; 针对北方岩溶水系统模拟, 可选择等效连续多孔介质模型, 重在耦合区域分布的岩溶溶孔－裂隙介质中慢速渗流与脉状分布的强径流带快速流; 对于南方岩溶区, 建议考虑建立分布式流域水文模型与能刻画集中管道流多流态变化的多重介质模型的岩溶地下水耦合模型。      

一种用于突发性场地污染模拟的解析模型

为了及时有效地应对各种突发性环境污染事故,有必要开发一种简单实用、适于各类型污染物的场地污染数学模型。通过污染事故发生后污染物在包气带、饱和带迁移转化的概化,建立了污染物运移的自由入渗模型以及降雨入渗模型并给出各自相应的解析解。无降雨时,考虑污染物在重力作用下随包气带向下渗透的作用,建立一维垂直入渗模型。有降雨时,考虑污染场地(包气带)中污染物迁移和转化的对流作用、扩散作用及挥发、生物降解、吸附、根系吸收等作用,建立包气带剖面二维溶质运移模型和饱和带平面二维溶质运移数学模型。建模过程中,假定降雨量的平均分布及土壤质地、水力参数以及有机物成分、种类均相同,同时假定污染物与多孔介质间的作用为线性吸附,植物根系对污染物的吸附遵循一级动力学。基于模型的解析解,实现案例的模拟计算。模拟结果表明:该模型具有适用范围广、模拟高效快捷等优点,能够较准确预测污染发生后污染物在土壤中的动向、到达饱和带的时间以及饱和带中污染物的迁移情况。     

土壤中溶质运移的数学模型及其解析解

首先给出了非均匀土壤中考虑水动力弥散尺度效应的一维溶质运移两区模型.然后在初始浓度为零,半无限一维空间内第一类边界条件下,推导出了可动区和不动区溶质浓度分布Cm(x,t),Cim(x,t)的解析表达式.     

本钢郑家屯潜水含水层弥散试验研究

在本钢郑家屯潜水含水层中进行了弥散试验，以Ｃｌ－为示踪剂，瞬时投放，根据流场条件，建立了二维水质运移模型。利用标准曲线法进行处理，得到了各监测井处的弥散度。对该试验结果进行分析，得到了在试验范围内，多孔介质中水动力弥散度的变化。     

弹性岩石层、区域重力异常和上地幔小尺度对流

在小尺度地幔对流模型的基础上 ,建立了顾及岩石层与地幔耦合的地幔对流模型。考虑到岩石层对上地幔小尺度对流的弹性响应 ,将上地幔视为一均匀的等粘滞系数的牛顿粘滞流体 ,其对流能量来源于下地幔 ,用热流体动力学基本方程得到的上地幔对流在壳幔边界处的垂向应力作为弹性板弯曲方程的垂直加载 ,来耦合弹性岩石层和可流动地幔。推导了两者耦合下区域重力异常和上地幔小尺度对流的相关方程 ,用以反演上地幔小尺度对流流场模式和岩石层底部拖曳力场格局。对比了有、无弹性岩石层影响的模型之间的差异 ,并对模型应用范围 ,特别是板块边界水平构造力可能产生的影响 ,作了进一步探讨。     

基于CPML边界条件的水下地质雷达数值模拟

水下的地质雷达探测与常规的地质雷达探测具有显著的不同点。文中对CPML吸收边界条件的公式进行推导,并通过数值模拟对均匀介质以及非均匀介质中吸收边界条件的吸收效果进行了验证,数值模拟的波场快照证明了CPML吸收边界条件在水下的地质雷达数值模拟中具有很好的吸收效果。通过对水平层状介质模型以及倾斜层状介质模型开展数值模拟,并结合实际探测的雷达图像,证明地质雷达对于水下地层的探测能够取得良好的效果;通过对空洞体位于不同深度时的数值模拟,证明了地质雷达对于水下的空洞探测也能对其位置及规模进行较为准确的判断。这为水下地质灾害的探测提供了理论依据及指导。     

宝鸡电厂灰场污染物运移趋势

本文运用非饱和带纯水流模型,预报未来灰场污染物运移趋势。作者依据过去10年污染深度及含水量分布值,以非线性规划理论为基础,建立识别模型,反演求参(D(θ)和K(θ).从研究区水文地质条件出发,建立一维非饱和流预报模型,采用有限差分数值逼近法求解。通过运营模型,预报了未来20年污染深度为4.0～6.0m,从而得出该灰场对地下水无影响的结论.     

樊家川油田河流相储层砂体非均质模型及剩余油分布

河道砂体内部沉积结构韵律性变化和夹层的发育导致垂向上储层形成严重的非均质性,从而控制了注入水垂向上的波及体积和剩余油的分布。根据多口取心井及检查井资料,建立了各类河道砂体非均质模型,并采用检查井水洗剖面详细描述和数值模拟方法,研究了砂层内不同夹层分布及其韵律性变化所产生的非均质模型中剩余油分布规律,为该油田高含水开发后期进行井网综合调整及其剩余油挖潜提供基础。     

Preliminary study on plasma membrane fluidity of Psychrophilic Yeast Rhodotorula sp.NJ298 in low temperature

The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.     

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正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprehensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose     

JOURNAL OF OCEAN UNIVERSITY OF CHINA

<正>Copyright Submfnion of a roanusatpt inks:that the work described has not been published before(exoept In the form of an abstrW or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere that its publication has been approved by ail     

Information for Authors

<正>The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research results on oceanography and marine fisheries.The fieldcovered include the physical,chemical,biological,geo-     

Hydraulics and Hydrology in Mountain Areas

<正>The 35th IAHR World Congress was held in Chengdu,China from September 8 to September 132013.The title of the conference was:"The Wise Finds Pleasure in Water:Meandering through Water Science and Engineering".During the congress,1239 papers were presented in 139sessions for oral presentations and 7 sessions for poster presentations.After the Congress,a Committee was appointed to select some of the best papers presented at the Congress for publication,after a     

Sea ice thickness measurement in spring season in Bothnian Bay using an electromagnetic induction instrument

As an important component of the cryosphere,sea ice is very sensitive to the climate change.The study of the sea ice physics needs accurate sea ice thickness.This paper presents an electromagnetic-induction(EM) technique which can be used to measure the sea ice thickness distribution efficiently,and the successful application in Bothnian Bay.Based on the electromagnetic field theory and the electrical properties of sea ice and seawater,EM technique can detect the distance between the instrument and the ice/water interface accurately,than the sea ice thickness is obtained.Contrastive analysis of the apparent conductivity data obtained by EM and the value of drill-hole at same positions allows a construction of a transformable formula of the apparent conductivity to sea ice thickness.The verification of the sea ice thickness calculated by this formula indicates that EM technique is able to get reliable sea ice thickness with average relative error of only 12%.The statistic of all ice thickness profiles shows that the level ice distribution in Bothnian Bay was 0.4-0.6 m.     

Thermohaline structure inhomogeneity associated with polynia at the northern margin of Emery Ice-shelf

Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.     

Phylogenetic analysis of cultivable bacteria isolated from Arctic sea-ice

Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.     

Information for authors

正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied