整体碾压混凝土拱坝工艺及温度场仿真计算

选用了整体碾压混凝土（ＲＣＣ）拱坝的可行施工工艺，提供了混凝土坝施工期到运行期温度场的仿真计算方法和温度信息处理方法。利用我国某碾压混凝土坝的现场实测结果，对温度计算值及变化进行了验证，结果良好。数值计算用来预测我国拟建的某碾压混凝土拱坝从施工开始到长时间运行的仿真温度变化。仿真计算表明工艺对施工期温度变化影响大，对由施工末期到运行期温降值也影响较大。根据温度场的变化规律选择了碾压混凝土拱坝合理的施工工艺。     

高碾压混凝土坝温度应力研究

根据碾压混凝土坝薄层浇筑、快速施工的特点，用三维有限元浮动网格法计算程序，对高碾压混凝土坝温度场和温度应力进行了仿真计算；揭示了不同横缝间距的坝体施工期温度场、温度应力和坝体最大温降应力的变化规律。该项研究对碾压混凝土坝设计具有参考价值。     

碾压混凝土重力坝温度场与温度徐变应力仿真分析

结合百色碾压混凝土坝的工程实际情况，采用三维有限元浮动网格法对该坝施工期和运行期温度场、温度徐变应力进行了仿真计算。计算中考虑了混凝土热力学参数随龄期变化、坝体分层浇筑过程及自重、水压力对温度应力的影响。仿真结果给出了温度场、温度应力分布及其随时间变化规律，为碾压混凝土重力坝的设计和施工中的温控提供了参考依据。     

RCC重力坝防渗体温度场的三维有限元浮动网格法仿真分析

利用三维有限元浮动网格法，对采用不同厚度的常态混凝土、二级配碾压混凝土、变态混凝土防渗结构的碾压混凝土坝温度场进行了仿真计算。结果表明，不同形态的混凝土防渗结构对碾压混凝土坝体温度场的影响不大；而防渗体厚度对其自身温度的影响较大，防渗体厚度过大或过小，都对其温控不利；对三级配碾压混凝土坝采用二级配碾压混凝土中等厚度(D=3m)的防渗体已能满足温控要求。     

考虑昼夜温差的碾压混凝土坝温度场仿真分析

采用碾压混凝土坝温度场和温度应力仿真计算程序RCTS,针对某碾压混凝土重力坝的结构设计和布置特点,严格模拟碾压混凝土实际浇筑过程,对施工期不考虑昼夜温差、考虑不同的昼夜温差、坝体表面保温等情况进行温度仿真计算,并且将仿真计算结果进行了比较分析.结果表明,施工期昼夜温差对碾压混凝土表面,特别是施工期长间歇面温度影响比较大,考虑昼夜温差的计算结果更加符合实际边界条件,不考虑昼夜温差的计算结果是偏于不安全的.     

高温季节碾压混凝土坝强约束区温控防裂方案研究

我国西南地区高温季节持续较长,碾压混凝土坝面临施工期温度裂缝的威胁．基于碾压混凝土坝施工期开裂机理,结合某大型碾压混凝土重力坝强约束区高温季节的施工,采用有限元仿真算法模拟了不同昼夜温差条件下的混凝土温度场和应力场发展过程,根据计算结果对表面保温和水管冷却过程中的具体参数进行优化,成果对同类工程具有参考价值．     

三峡右岸碾压混凝土围堰施工温度场仿真分析

根据碾压混凝土围堰的施工特点，用瞬态热传导三维有限元分析方法，对三峡右岸碾压混凝土围堰施工期的温度场进行了仿真分析．分析中考虑了混凝土的热学参数及边界条件随龄期变化及分层的实际情况，得到了围堰在整个施工期及运行期温度场的时空分布规律和一些有益的结论，并为控制温度应力提供了重要的依据．     

沙牌碾压混凝土拱坝温度场仿真计算

在条件并层、接缝单元、分区异步长等仿真分析理论的基础上,进一步研究了网格自动生成与并层问题、单元形状问题、接力计算问题、合理时间步长问题、边界初始温度赋值问题及提前蓄水时温度边界的处理问题等等;并以沙牌碾压混凝土拱坝施工过程温度场仿真分析工程实例,证明其结论可供设计人员参考。     

碾压混凝土拱坝施工期温度荷载的计算方法

温度荷载是碾压混凝土拱坝施工期引起坝体开裂及裂缝扩展的重要原因.文章分别介绍了美国垦务局公式和<规范>公式计算碾压混凝土拱坝温度荷载的方法,并与运用温度场仿真计算与反分析相结合的方法进行对比,得出后面的方法有更大的优越性.     

碾压混凝土坝的温度应力

对碾压混凝土坝施工期非稳定温度场和应力场进行仿真分析，对空间域用有限单元法离散，在时间域用有限差分法计算，分析与计算中，考虑混凝土徐变对温度应力的影响，一典型工程的计算结果表明：环境温度对碾压混凝土坝的最高温升有明显影响，大体积混凝土结构的温度下降到年平均温度需要一个很长的时间过程，混凝土表面的早期裂缝通常在后期闭合，而内部裂缝往往在施工结束几年后发生。因此，混凝土坝后期温度应力是温控设计必须考虑     

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