多层隔震结构近似实空间解耦及地震作用取值

为研究多层非经典阻尼隔震结构响应及其地震作用取值,首先建立了多层隔震结构响应近似实空间解耦分析法,并基于随机振动理论将结构位移随机响应方差解析分解为系列标准振子的位移与速度随机响应方差的线性组合;然后利用系列标准振子最大响应与反应谱的对应关系,建立了多层隔震结构基于抗震规范加速度反应谱的位移最大响应及其等效静态地震作用取值的近似解析分析法,并给出算例。采用本文方法计算的结构位移时程分析、位移响应方差和层间剪力设计值的最大误差分别仅为0.392 8%、0.020 6%和0.079 9%,结果表明该方法简便实用,精度较高,可用于工程实际。     

平面不规则高层建筑双层隔震体系的抗扭分析

以某高层不规则框架结构为例,输入双向地震波,采用SAP2000分析罕遇地震作用下中间隔震层位于不同位置时双层隔震体系的减震性能,研究不同偏心率下不规则隔震结构的扭转响应.研究表明:中间隔震层位于3层时双层隔震体系的水平向减震系数、层间位移角和位移比均最小;双层隔震体系隔震层偏心率的大小对周期比和层间位移角的影响不大,隔震层偏心率较小时,位移比也较小,隔震体系具有良好的抗扭性能.因此,对于平面不规则高层建筑双层隔震体系,隔震层小偏心率且中间隔震层布置在结构中部偏下位置时,可有效限制结构的扭转响应.     

土-结构动力相互作用对橡胶支座隔震结构的影响

采用子结构法,建立了频域内土-结构动力相互作用下的橡胶支座隔震结构的分析模型及相应的运动方程,通过数值仿真2个具有埋置刚性基础的剪切型基础隔震结构的地震反应,并选用多种地基土,较为系统地分析计算了不同地基土参数组合下结构的隔震效果和地震响应.结果表明,设置橡胶支座隔震层可以削弱土-结构动力相互作用对结构动力特性的影响,减小结构相对于场地运动的楼层位移和基底位移.同时,土-结构动力相互作用使橡胶支座隔震效果有所降低,且影响程度与上部结构刚度成正比,与地基土刚度成反比.     

平稳随机地震激励下TMD-基础隔震混合控制体系的减震效果分析

文章对随机地震激励下TMD-基础隔震混合控制体系的减震效果进行了研究,建立了混合控制体系的运动方程,运用状态空间法求解该混合控制体系的随机响应,得到体系各层的响应功率谱和响应均方根值;给出了在上部结构位移最优化条件下求解体系中TMD最优参数的计算表达式;通过与基础隔震结构对比分析了该混合控制体系的减震效果。分析结果表明:混合控制体系在使隔震层位移得到减小的同时,可以更有效地控制上部结构的地震响应;对于位于不同场地上的结构,该混合控制体系仍能发挥一定的减震效果。     

建筑物滑移基础隔震结构的基本体系分解法

提出了滑移隔震结构基本体系的概念,根据振型分解法将上部结构解耦为互相独立的单质点体系.如果隔震层质量合理分配到上述单质点体系,则结构有可能进一步解耦,形成与上部结构模态数目相同的隔震基本体系.上部结构的反应可由基本体系的相应反应通过振型叠加得到,隔震层的反应与任一基本体系的相应反应量相同.工程算例表明,该方法完全满足工程精度要求,对该类非线性系统进行降维解耦的思路具有较高的可行性.     

新型多维隔减震装置在高烈度区工程中的应用

为提升建筑结构多方向的抗震能力,基于黏弹性材料的高耗能特性提出了一种由筒式阻尼器和隔震支座组成的新型多维隔减震装置,并应用于云南某小学的实际工程.首先通过试验得到筒式阻尼器的耗能特性,然后建立多维隔减震装置的力学模型和受控结构运动微分方程,通过对比计算研究装置的多方向隔减震效果.结果表明:装置中的筒式阻尼器具备较强的耗能能力,且其力学性能会随激励频率和幅值变化而变化;结构中加入新型装置后,水平和竖向的地震响应均得到有效控制;在EI Centro地震波作用下,与橡胶隔震结构相比,多维隔减震结构X方向和Y方向的最大隔震层位移分别降低39.5%和38.9%,X方向和Y方向结构最大层间位移分别降低39.4%和45.5%,Z方向最大位移和加速度响应分别降低12.2%和6.3%,说明新型多维隔减震装置可有效减轻结构多方向地震响应.     

竖向混合结构阻尼矩阵近似解耦计算的误差分析

将竖向混合结构等效成两自由度结构模型,对该两自由度模型进行不同子结构参数取值下的近似解耦计算,分析其模态阻尼矩阵对角占优程度和近似解耦计算结构响应误差情况。研究结果表明:在不同子结构特性下,模态阻尼矩阵对角占优指数和位移误差指数的衰退特征具有相似性。因此在竖向混合结构动力分析时,可以采用对角占优指数来判定采用近似解耦计算的可行性。     

近断层地震作用下基础隔震层弹簧软限位分析

基础隔震能有效减轻结构地震响应.但在近断层脉冲型地震作用下,隔震结构的隔震层会发生较大位移,导致隔震结构侧倾失稳.本文采用弹簧限位装置进行软碰撞限位,利用软件SAP2000计算近断层地震作用下限位隔震结构的动力响应,分析限位装置不同预留距离、不同限位刚度对隔震层最大位移和上部结构最大层间位移的影响.     

层间隔震结构减震机理的数值模拟分析

以振动台试验模型为背景,隔震垫采用铅芯橡胶隔震支座双线性滞回阻尼和粘滞阻尼的粘塑性分析模型,隔震层采用粘塑性分析模型,建立层间隔震结构的动力运动方程.同时,使用有限元分析软件ANSYS对该试验模型进行非线性有限元动力分析,获得层间隔震结构在地震动下的响应.分析结果表明,隔震层位置越低,隔震效果越好.随着隔震层设置位置下移,层间隔震体系在结构动力特性上体现为前两阶模态质量参与系数的比例发生变化.在中间层隔震区域,隔震层上部子结构反应基本上由一阶振型决定,而下部子结构反应却以二阶振型为主.隔震层上部子结构层间位移较稳定,可以近似为平动;下部子结构层间位移呈现抛物线状,且下部结构最大层间位移常出现在下部结构的中间位置.     

随机地震激励下基础隔震结构的复模态解析法

运用复模态方法,系统研究了基础隔震结构在随机地震激励下的响应.由于基础隔震结构运动方程为非经典阻尼和非对称质量、刚度情况,故采用复模态解耦振动方程,得到基础隔震结构的响应解析解.     

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.     

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