轻非水相流体污染物运移的离心模型

用甲苯作为轻非水相流体(LNAPL s)污染物,采用高加速度土工离心试验技术模拟LNAPL s在非饱和土体中的长期迁移过程。利用紫外可见分光光度计分析试验中土样的污染物质量分数。通过图像采集得到了甲苯的时空分布特征和长期迁移规律。结果表明,不同加速度试验得到的甲苯迁移特征相似,因此用较高加速度离心模型试验模拟LNAPL s在非饱和土中迁移过程是可行的。     

某渣场污染物在非饱和岩土介质中的迁移模拟研究

为研究某渣场污染物对周边地下水的污染状况,通过对渣场场地非饱和土壤弥散、渗流特性试验,并运用模拟地下水溶质迁移的软件Comsol Multiphysics建立渣场污染物在非饱和岩土介质中的迁移模拟计算模型.试验结果表明:土壤水扩散率D(θ)和非吸附性溶质C1-1的水动力弥散系数Dsh(θ)与土壤含水率θ成显著幂函数关系;同一吸力水头下,黏粒含量越高,储水能力越强,脱水速度越慢,即黏土②土样其持水性能远远高于熔炼渣①土样.100年内渣场污染物氟和锌的迁移污染对周边地下水污染浓度满足二类水标准;通过对渣场周边地下水试验结果表明:渣场现状下对周边地下水并未形成污染,这也验证了采用Comsol Multiphysics软件对渣场污染物迁移模拟分析的可靠性.     

地浸采铀地下水中放射性污染物迁移的模拟

地浸采铀对地下水的放射性污染是一个倍受关注的环境问题．本文对新疆某地浸采铀矿山井场地下水污染的监测结果进行了分析,建立了地浸采铀井场地下水中污染物迁移的动力学模拟,对污染物在地下水中的迁移规律进行了数值模拟．在地浸生产期间,有少量的放射性污染物U和硫酸向井场外迁移,但污染物：迁移速度和迁移距离都比较小,污染物浓度较低,污染物呈不规则的齿形迁移,U和SO4^2-的迁移规律与迁移趋势是一致．数值模拟对分析地浸采铀矿山地下水中污染物的迁移规律、预测和控制污染物的迁移提供有效的途径和依据．     

非饱和土壤中重金属污染物迁移机理分析

视土壤为非饱和多孔介质,将描述非饱和多孔介质中多种迁移场量耦合的热质传递模型,结合土壤中溶质迁移的对流-弥散规律,并考虑土壤固体骨架对重金属污染物的吸附特性,建立非饱和土壤中重金属污染物迁移的数学模型.数值分析了非饱和土壤不同深度处和土壤含湿量不同时,污染物在土壤中的迁移状况.随着土壤深度的增加,污染物在土壤中的迁移呈现滞后性;湿含量较高的土壤,在迁移状况趋于稳定时,污染物沿土壤深度的增加其浓度梯度相对较小,数值分析所得污染物在土壤中的迁移规律与文献已有试验结果相一致.因此,所建立的数学模型和数值分析结果,可为分析重金属污染物在土壤中的迁移状况和修复重金属污染的土壤提供一定的理论指导.     

污染物在非饱和土壤中迁移规律的试验研究

借助于土柱物理模型装置，试验研究了保守性污染物在非饱和土壤中的迁移规律，得到了污染物瞬时输入和连续输入条件下，非饱和土壤中污染物浓度时空变化的过程。在分析实测资料的基础上，提出了采用考虑可动水体与不可动水体因素的数学模型来描述土柱内污染物的迁移过程。根据实测资料和数学模型的数值解，运用最优化技术率定模型参数，得到了具有应用价值的参数成果。     

基于Hydrus-1D的包气带污染物运移规律研究

自然条件下,土壤表层污染物随降雨入渗是污染包气带及地下水的一个重要途径。以河北省廊坊市某化工园区为研究区域,通过现场取样及室内试验获取土壤参数,刻画包气带剖面概念模型,利用Hydrus-1D软件预测污染物在包气带中的迁移范围和迁移趋势,具有极强的便利性,为非饱和带地下水环境影响评价提供参考。研究结果表明,在污染物迁移过程中,受土壤自净作用影响,最大迁移距离为15.5 m,未穿过包气带污染含水层。     

GMS在饱和—非饱和地下水流动及核素迁移模拟中的应用

为了研究某饱和——不饱和区域的地下水流动和核素迁移规律,采用GMS软件数值模拟的方法,介绍了应用GMS解决这类问题时的具体步骤,论述了初始条件、边界条件的设置技巧。模拟得到了该区域合理的地下水流场和不同时刻的核素质量浓度分布,与相关程序计算结果吻合较好。研究结果表明:GMS在饱和—非饱和地下水流动及核素迁移模拟中,具有较高的应用价值。     

焦作地区浅层地下水硬度污染机理及迁移预测

分析焦作地区浅层地下水硬度污染物与地下水其他化学特征的相关性,研究该区浅层地下水硬度的污染机理,运用Visual Modflow软件建立水质模型,模拟预测浅层地下水中硬度污染物的迁移规律。结果表明:该区浅层地下水硬度污染严重,主要原因是工矿企业污废水排放和对浅层地下水的不合理利用,造成进入浅层地下水的污染物增多,直接引起浅层地下水硬度升高;另一方面使得本区浅层地下水的化学场、动力场发生变化间接引起本区浅层地下水硬度升高。模拟结果显示,浅层地下水中硬度污染物的迁移明显受到水文地质条件的影响,迁移方向与地下径流方向基本一致,自西北向东南方向迁移。     

氟在非饱和带迁移的动态特性研究

通过氟迁移土柱模拟试验 ,讨论了非饱和带氟迁移的动态特征。对高氟地下水灌溉可能产生的氟环境问题的研究具有一定的实践意义。     

非饱和土路基水气迁移规律及其影响因素实验

非饱和黏土的水气迁移影响着路基服役期间的安全运行和长期使用性能的保障。研究非饱和土路基水气迁移规律对路基路床湿度的影响具有重要的工程应用价值和意义。本文通过室内试验模型,运用高低温交变恒温箱改变环境温度,模拟四季环境温度对水分迁移的影响。模拟非饱和黏性土气态水迁移过程,并进行影响因素的敏感性分析。获得非饱和黏性土的水气迁移规律并进行影响性因素评价,实验结果表明,非饱和土水气迁移过程中,含水率梯度对气态水迁移量影响较大;迁移时间对液态水迁移影响较大;低温环境下以液态水迁移为主,随环境温度升高气态水迁移量占比逐渐升高。含水率梯度,含水率水平,压实度,迁移时间,不同环境温度均对气态水迁移量均有贡献,其中压实度对其影响最小。在实际工程中应更重视水气两相迁移对路基土体性能的影响。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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