粘性土应力路径试验

利用GDS多功能三轴仪,对南京河西地区原状粘性土进行了常规三轴压缩、减压三轴压缩和等p应力路径的固结不排水三轴试验,探讨不同应力路径下粘性土的变形和强度特性.实验表明：不同应力路径下土的应力应变关系都呈曲线形态相似的非线性应变硬化型,而土的峰值强度和土中孔隙水压力差异明显;相同应力路径试验得到的有效应力路径形态一致,常规三轴压缩试验中有效应力路径呈S形.     

黄土状土和火山灰粘性土的动剪强度研究

实际地震危害表明,不仅饱和的细砂、粉砂地基会产生液化,而且饱和的粉土、粉质土地基也会产生液化．文中通过对我国西北地区特殊土———黄土状土和日本的特殊土———火山灰粘性土（广泛分布于日本关东地区,且大量用于道路填土工程）进行了一系列动力三轴试验,研究了它们在动荷作用下的动力特性,孔隙水压力的变化以及动、静强度的比较,测定并分析了不同的固结比对破坏时土的动剪强度和动孔隙水压力的影响,得出了黄土状土的动剪强度随相对密度变化的关系及火山灰粘性土的动剪强度随固结比变化的关系式．     

纤维加筋粘性土边坡的模型试验和计算分析

纤维加筋能显著提高粘性土的抗剪强度,并使之具有裂而不断的特性。介绍了纤维加筋粘性土和素土边坡的离心模型试验成果。试验过程中详细观察并记录了边坡的变形和破坏情况。也介绍了对纤维加筋土边坡的数值计算结果。所采用的把筋的作用当成外力加在土单元上的等效附加应力法的计算思想对于其它加筋型式的数值分析也是适用的     

一般应力条件下土的抗剪强度参数探讨

土的抗剪强度指标一般通过室内常规土工三轴压缩剪切试验获得,但实际工程中土体并不处于这种理想的轴对称应力状态。因此,研究一般应力条件下与三轴应力条件下强度参数之间的相互关系十分必要。针对不同中主应力系数,基于推广的空间准滑动面强度准则即SMP准则及广义Mises准则,通过理论分析建立了各种应力状态下一般粘性土强度参数之间的换算关系,比较了不同中主应力系数情况下和平面应变条件下的强度参数。结果表明,中主应力系数对土的抗剪强度具有比较显著的影响。     

透明土强度特性及模拟黏性土的可行性试验

采用体积比为2.5:1的15号白矿油和正十二烷混合液与无定形硅石粉末配制成透明土以模拟黏性土.进行了120个不同应力状态透明土样的直剪固快强度试验及常规固结压缩试验,给出了透明土在不同应力状态下的抗剪强度值,并与典型黏性土进行了对比分析,得知两者在强度及压缩特性上具有高度相似性;通过等沉降速率的室内压板载荷试验,得到了荷载-沉降曲线、土体极限承载力、土体速度场、土体位移场,与既有研究结果进行了对比,验证了透明土模拟黏性土应用于模型试验的可行性.     

基于颗粒流离散元的粘性土三轴剪切试验数值模拟

为了研究粘性土体的工程力学性质,本文通过对粘性试样进行室内三轴固结排水试验,得到了试样土体的应力—应变关系曲线以及强度指标,基于颗粒流离散元法的原理,利用PFC3D软件建立三轴试样模型,并设定颗粒间的接触为接触黏结模型,通过颗粒流数值试验对细观参数进行标定,从细观角度对粘性土的工程力学特性做了一定的研究。对比了不同围压下数值试验与室内试验的应力应变关系曲线,得到了较好的模拟效果。分析细观参数的变化对粘性土的应力—应变关系曲线的影响,得出边界条件、孔隙率、粘结强度、摩擦系数、接触刚度等细观参数的取值对粘性土的宏观力学性质有着显著的影响并对影响规律做了探讨,为今后的三轴试验颗粒流数值模拟提供了有价值的参考。     

考虑应力修正的麦秆土直剪试验抗剪强度指标研究

为了分析麦秆含量对土壤抗剪强度指标的影响,获取更可靠的抗剪强度指标,推广能源节约型农业耕作生产,用TMS-PRO计算机控制质构仪做麦秆剪切试验。用应变控制式直剪试验研究原状与重塑麦秆土抗剪强度指标,分析麦秆含量对土壤抗剪强度指标的影响。应用应力修正法对直剪试验的正应力与剪应力进行修正,研究修正前、后麦秆土抗剪强度指标的变化量及随麦秆含量的变化规律,并对原状与重塑麦秆土修正前、后的黏聚力、内摩擦角拟合线分别进行叠加。试验结果表明:麦秆抗剪强度随含水量的增加而增大,麦秆土抗剪强度指标随麦秆含量的增加而增大,黏聚力符合线性拟合的规律、内摩擦角符合二次函数拟合的规律。考虑应力修正后原状与重塑麦秆土黏聚力较修正前提高了24%、内摩擦角较修正前提高了18%;未经修正的原状与重塑麦秆土在麦秆含量为0.58%时具有相同的黏聚力,在麦秆含量为0.37%时具有相同的内摩擦角;考虑应力修正后的原状与重塑麦秆土在麦秆含量为0.65%时具有相同的黏聚力,在麦秆含量为0.40%时具有相同的内摩擦角;在交汇点之后麦秆土抗剪强度指标增速表现为原状大于重塑。     

压实膨胀土饱和抗剪强度的变动性

饱和抗剪强度是工程设计的基本指标与描述非饱和抗剪强度的基准,然而其具有一定变动性,为探讨变动规律,在四联直剪仪上对6种制样压实度下的荆门弱膨胀土开展一维无荷载膨胀-固结-慢剪试验,将其结果与不同水化状态下的三轴试验数据对比.结果表明:相同应力状态下孔隙比状态的差别是造成该变动性的主因;先期应力历史与水化状态的差别导致相同应力状态下孔隙比状态的差异.水化状态为浸水膨胀稳定(膨胀势完全释放)后的饱和状态时,有效黏聚力随孔隙比增大规律性降低,有效内摩擦角对孔隙比并不敏感.水化状态为膨胀势未完全释放的饱和状态时,有效内摩擦角显著高于浸水膨胀稳定后的相应值,原因是膨胀势引发的剪胀效应造成的剪切抗力提高,反映于有效内摩擦角的增大.浸水膨胀稳定后有效内摩擦角是低且稳定的,相关工程应用及描述非饱和抗剪强度时,建议选取浸水膨胀稳定后的饱和抗剪强度参数作为相应指标.     

粘性土改性细砂的强度特性

粉细砂在宁夏北部分布广泛,埋藏浅,土层深厚,存在不同程度的液化倾向。围绕粘性土改善砂土抗液化性能,以银川地区粉细砂为对象,干密度,含水率和粘性土掺量为因素,设计正交试验方案,试验研究了粘性土改性细砂的强度特性,分析了各因素的作用规律,及其显著性,建立了粘聚力与干密度、粘性土含量及含水率间的多元非线性回归模型,结合土的颗粒组成和矿物组成分析了作用机理。干密度的增大能显著提高改性细砂的强度指标,粘性土可非常显著的提高细砂的粘聚力,从而显著改善细砂土的抗液化性能,且对强度不会产生明显的不利影响,建立的粘聚力关系模型显著性高,相关性较好。     

寻乌离子型稀土矿体抗剪强度特性试验研究

江西寻乌的离子型稀土矿体为属于粉土,是介于砂性土和黏性土之间的一种过渡性土。研究该类矿体的抗剪强度计算方法,对于分析原地浸矿过程的边坡稳定具有重要意义。应用水土分合算理论,引入水压率的概念,从土的微观层面上分析水对矿体强度的影响,设计出一种室内测定水压率的试验装置。测定不同孔隙比下的水压率,采用GDS三轴仪测试总应力指标和有效指标,分别计算水土合算、水土分算和水土统一算法下稀土矿体的抗剪强度。试验研究结果表明:矿体孔隙比越大,水压率越大,饱和矿体的抗剪强度随着水压率的增大而减小;寻乌稀土矿体的水压率值为0.90~0.92;因而,采用水土统一算法计算得到的抗剪强度值与水土分算法的抗剪强度值更接近,与水土合算下的抗剪强度值相差较大。     

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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