黄土的湿陷性与显微结构特征研究——以咸阳市区为例

对咸阳市区黄土湿陷性与微结构的系统研究,发现咸阳市区黄土的湿陷性与微结构特征随地貌单元有不同的变化.渭河三级阶地黄土地层厚度大,湿陷性较强,黄土微结构以支架大孔半胶结结构为主;二级阶地湿陷性次之,黄土微结构以支架大孔-镶嵌微孔半胶结结构为主;一级阶地湿陷性最弱,黄土微结构较为致密,以镶嵌微孔胶结结构和絮凝胶结结构为主.黄土的湿陷性与微结构特征关系密切,支架大孔半胶结结构的黄土湿陷性较强,镶嵌微孔半胶结结构的黄土湿陷性较弱,镶嵌微孔胶结结构和絮凝胶结结构的黄土不具湿陷性.     

湿陷性黄土夯实效果评价及模拟分析

以洛阳华润热电新建电厂工程为背景,开展了湿陷性黄土的强夯试验,探讨了强夯处理黄土湿陷性的效果.同时建立强夯的三维动力分析有限元模型,对黄土强夯效果的影响因素进行了分析.分析结果表明:采用强夯工法能很好地消除黄土的湿陷性;强夯能级越大,强夯的径向影响范围和竖向影响深度越大;在处理深厚湿陷性黄土时,相同能级条件下宜采用半径较小的夯锤.     

强夯法处理辽西湿陷性黄土路基的效果分析

为了确定强夯法处理辽西湿陷性黄土路基的技术参数,采用现场测试和室内试验相结合的方法,分析并对比了试验路段在强夯前后的黄土物理力学性质的变化.结果表明:夯击能为800～1600 kN·m、夯击数不小于8击,对处理深度4～6 m的湿陷性黄土较为有效,不仅可消除湿陷性,并可较大幅度降低压缩性.该成果已应用于阜新一朝阳高速公路湿陷性黄土路基处理工程中.     

强夯加固技术在湿陷性黄土路基处治中的应用

结合具体试验路段,通过颗粒分析、电镜扫描、CBR试验、无侧限抗压强度与固结试验等手段对强夯加固后路基黄土的处治效果进行分析.结果表明,强夯后的路基黄土微结构由絮凝状、支架大孔结构转变为镶嵌结构与叠置结构;不同夯击能下路基黄土的有效加固深度可以通过无侧限抗压强度试验确定;路基黄土的压实度与CBR值服从幂指数关系,与回弹模量和湿陷系数服从指数分布.     

强夯法处治湿陷性黄土路基的数值分析及应用

针对Ⅲ级自重湿陷性黄土遇水强度降低、变形较大的情况,采用数值模拟和现场试验的手段,分析强夯处治后位移场、应力场和塑性区的变化规律.以某高速公路段为例,设计强夯处治方案,并通过现场夯沉量试验和标准贯入试验,得出强夯处治Ⅲ级自重湿陷性黄土的最佳夯击次数及有效的处治深度.研究表明,强夯单点夯实作用后位移场和应力场重新分布,其有效的水平夯实范围为3m,剪切塑性区体积增大;Ⅲ级自重湿陷性黄土最佳的夯击次数是5次,强夯竖向有效处治深度为4m.数值模拟结果与现场试验数据对比分析结果一致,证明强夯处治方案合理,强夯处治对于Ⅲ级自重湿陷性黄土地基效果显著.     

强夯处理湿陷性黄土的应用

结合工程实例,从地基特点、强夯施工工艺及技术参数、检测结果3个方面介绍了高能级强夯法在处理湿陷性黄土和回填土中的应用,并对施工中的问题进行了分析,指出了强夯处理湿陷性黄土的效果。     

高能级强夯在某电厂净化站工程中的应用

体有效加固深度既是反映地基处理效果的重要参数,又是选择地基处理方案的重要依据。采用高能级强夯加固深厚地基,特别是大孔隙湿陷性黄土地基、山区大厚度非均匀块石回填地基和抛石填海地基等可进一步提高地基土强度和均匀性,降低压缩性,消除湿陷性,改善其抵抗振（震）动液化的能力等,使强夯法的经济高效性得以更加充分地施展。文章结合某电厂净化站工程湿陷性黄土地基处理,对高能级强夯的关键技术、检测方法和综合评价进行了阐述,可供类似工程参考。     

西安黄土显微结构类型

黄土的显微结构是在黄土物质堆积、成土作用过程中形成者。对它的研究有助于解决黄土成因、黄土工程地质性质等有关的理论与生产问题。根据扫描电镜和偏光镜下的观察分析,西安不同时代黄土显微结构特征按照碎屑颗粒的结构,粗颗粒的接触关系及胶结类型大致归纳为五种常见的主要类型:①粉砂细粒支架薄膜胶结类型。②粉砂细粒支架—镶嵌孔隙胶结类型,③粉砂细粒镶嵌一支架孔隙—斑状胶结类型,④粉土微粒分散—镶嵌斑状胶结类型及⑤粉土微粒分散基底胶结类型。     

陇东庆阳西峰地区黄土湿陷性分析

黄土的湿陷性是一个复杂的物理化学变化过程,其影响因素也是多方面的,其中黄土特殊的物理力学性质与其湿陷性就有着密切的关系。首先对陇东庆阳西峰地区某场地布置的探井所揭露的地层条件进行了概述,然后选取部分探井内扰动黄土样做了矿化成分试验。结果发现研究区黄土中易溶盐总含量很少,对研究区黄土湿陷性基本无影响。接着通过对研究区多组原状黄土样的室内试验数据进行大规模的统计分析,总结了研究区黄土的不同物理力学性质指标随黄土埋藏深度的变化规律;并根据所取土样的湿陷性试验结果对该区黄土进行了湿陷性评价。最后在此基础上对该区黄土湿陷系数与其不同物理力学性质指标间的关系作了探讨,认为这些指标反映了黄土的物质成分、结构特征和当前的赋存状态等属性,对研究区黄土湿陷性有不同程度的影响,这也为该区黄土场地的建设提供一定的理论指导参考。     

黄土湿陷性质的微观研究

本文分析研究了黄土的微观结构与其湿陷性之间的关系,通过对微观照片的分析,把土中孔隙按大小划分为4种类型,按照颗粒的徘列形式又可划分为架空孔隙、镶嵌孔隙和粒内孔隙,其中架空孔隙是造成黄土湿陷的基本原因。而不同孔径的孔隙对黄土湿陷性的影响是不同的,孔径20μm可以作为一个区分的标准,孔径大于20μm孔隙含量的增加会使湿陷性增高。     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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