竖向振动复合集总参数模型实验结果与理论结果的对比

根据基础振动弹性半空间理论,推演明置基础竖向振动复合集总参数模型.通过采用不同尺寸的块体模型基础,在明置和埋置情况下施加初速度,使基础发生自由振动,将实验结果与采用基础竖向振动复合集总参数模型的计算结果进行比较.研究结果表明:实验结果与计算结果相吻合.利用该模型可以计算均质半空间上块体基础在竖向扰力作用下任意频率、任意形状(不包括环型)的明置和埋置基础的动力响应.     

弹性半空间上矩形基础稳态振动积分变换解

采用双重Ｆｏｕｒｉｅｒ变换分析位于弹性半空间上,受竖向稳态荷载作用下矩形基础的振动问题,通过分析得到位移的积分变换解,并由该解得到短形基础稳态振动下的动刚度,通过解的数值计算分析,讨论了泊松比和基础形状动刚度的影响。     

频率相关域的桩基-结构竖向-水平振动特性分析

导出了一种可考虑土的分层以及桩顶轴向力参与作用的计算土介质中群桩动力相互作用因子的方法,进一步增强了S-R简化模型的应用效能.利用子结构理论,可计算任意构型、桩数、土层属性下的群桩结构系统动力反应,其计算工作量较小,便于工程应用.通过一桥梁墩基结构的地震反应分析表明:考虑竖向振动附加影响的水平激振作用会产生相当的附加变位,致使水平群桩阻抗效应减少;同时桩间动力相互作用影响也较单一水平力作用时有明显规律性的增强;桩土子结构的柔性参与在一定程度上可降低体系水平动力反应.     

半空间地基与正交异性矩形中厚板相互作用解析解

将3个广义位移变量描述的正交各向异性矩形中厚板的控制方程,与基于弹性半空间地基受任意竖向荷载作用的位移积分解建立的板与地基变形协调方程相结合,用三角级数法,得出弹性半空间地基上四边自由正交异性矩形中厚板受任意竖向荷载作用的解析解.用该方法对算例进行计算,并将其数值结果与文献结果进行对比,发现吻合良好,说明了该方法的有效性.     

剪切波作用下土一结构体系的耦合响应

讨论了几何偏心和非均匀地面激发对于基础埋置在弹性半空间中的单层结构的影响．地面激发为水平和竖向简谐剪切波．数值结果表明：剪切波对于建筑在软土地基中又有一定埋置深度的低矮建筑物有较大影响．设计中，以自由场地面运动记录取代建筑物基底运动记录会得到较大的整体动力响应值     

挑梁下R.C.构造柱受力性能的研究

利用ANSYS有限元软件对27个结构模型进行了线弹性分析,得出单层任意荷载作用下带挑梁R.C.构造柱截面竖向轴力计算公式,并推导出多层任意荷载作用下带挑梁R.C.构造柱的截面竖向轴力计算公式。通过与有限元计算值对比,该公式是可行的、偏于安全的。     

弹性半空间地基上正交异性矩形中厚板的弯曲

为了分析弹性半空间地基上正交异性矩形中厚板的弯曲解析解,将3个广义位移变量描述的弹性半空间地基上四边自由正交各向异性矩形中厚板的弯曲控制方程,与基于弹性半空间地基受任意竖向荷载作用下的静力位移积分解建立的板与地基变形协调方程相结合,用三角级数法,得出弹性半空间地基上四边自由正交异性矩形中厚板受任意竖向荷载作用下的弯曲解析解,即得出了地基反力、板的挠度及板的内力的解析表达式。研究结果表明,该方法克服了数值法的弊端,取消了Winkler地基模型或双参数地基模型的假设,从而得到板的内力及地基反力更合理、更精确的分布规律。     

桩-承台竖向强迫振动试验和分析

采用横观各向同性 (TI)层状弹性模型来模拟半空间上的层状场地 ,计算中忽略土体水平位移对竖向位移的影响 .用常系数阻尼器代替半空间 ,以吸收上部场地传至下边界的振动能量 .利用薄层元素法和子结构法建立运动方程 .在推导过程中 ,先利用格林公式算得自由场地刚度矩阵 ,再与桩单元刚度矩阵拼装得到桩的竖向总刚度矩阵 ,在此基础上推出单桩 -承台及双桩 -承台体系在垂直简谐荷载作用下的阻抗函数 ,其中双桩的阻抗函数考虑了桩 -土 -桩的动力相互作用的影响 .利用牛顿第二定律推导出这 2种体系在竖向强迫振动下的响应公式 .利用某次桩基动力试验所得的土参数和激振器数据 ,分别计算出这 2种体系的第一共振频率及频响曲线 ,并将计算结果与试验结果进行比较 .     

考虑基岩作用的圆形粘弹性地基振动分析

针对Merchant粘弹性本构模型，从轴对称饱和地基动力方程出发，运用Hankel积分变换，研究了粘弹性地基的竖向振动问题，获得了位移、应力、孔隙水压力及渗流量的积分形式解．并由此结合数值算例，讨论了粘弹性地基受动力荷载作用的振动特性．结果表明：地基竖向振幅沿半径呈波动衰减，粘弹性土体竖向振幅随半径变化要比弹性土体的小．     

埋置高速移动荷载作用下黏弹性半空间地表响应规律研究

分析不同埋深的高速移动荷载作用在黏弹性无限半空间的响应规律. 推导了埋置移动荷载作用下均匀无限黏弹性半空间地表响应的解析解,在柱坐标系下利用时间的拉普拉斯变换和位移的坐标变换得出了埋置移动荷载下黏弹性半空间的动态响应的二维积分解析解,之后用IFFT及坐标变换计算二维积分,提高了运算效率,最后分析了不同埋深、移动荷载速度情况下地表动力响应规律,发现了移动荷载在超Rayleigh波波速时地表位移出现明显的非对称性.      

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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