论述大体积混凝土的施工准备

在重大工程项目和高层建筑的施工过程中，大体积混凝土施工是工程的施工控制要点之一，需要从混凝土施工的部署、混凝土的原材选择和优化配合比、混凝土的供应、搅拌、测温、防裂控温养护等方面采取先进的施工技术和措施来确保混凝土的施工质量，避免因水化热和收缩引起的裂缝。大体积混凝土施工过程的主要技术要点可分为施工准备、施工措施、保温养护、温控监测等四大部分，在实际工程中，随着相关施工规范的不断落实以及工程经验的积累，施工单位在施工措施、保温养护、温控监测等阶段对工程质量的把握已经有了相当的经验．并形成了相对成熟的技术方案。然而，施工准备作为整个工程的前提，作为所有后续工作顺利进行的保证，单一性极强，在工程中未能形成系统的技术方案．由于准备工作存在不足或错误．往往给工程的施工造成混乱．本文结合广东某大型项目的大体积混凝土施工工程．对大体积混凝土施工中的施工准备进行阐述，提出了准备过程中技术准备、施工准备、组织准备的一些可供借鉴的方法。     

大体积混凝土冬季施工控制研究

混凝土的冬季施工，随着施工高速化、结构大型化和建筑造型多样化的发展，施工质量和功能的要求也越来越高．加之无数经验教训，促使人们对混凝土的冬季施工越来越加以重视。文章主要从原材料、配合比、热工计算、混凝土的浇筑、运输及养护等几个方面．阐述了大体积混凝土在冬季施工的控制方法。     

浅谈高性能混凝土在顶山隧道模型施工中的应用

顶山隧道二次衬砌施工模拟试验，是模仿隧道的实际地质条件和周边环境建造一个长14．4m，宽6．02m，高3．9m的隧道模型，其混凝土设计强度等级为C30。针对不同的部位分别采用普通混凝土、普通高性能混凝土、掺膨胀剂高性能混凝土、掺纤维高性能混凝土。模型施工的主要目的是，试验中低强度高性能混凝土的施工方法及各项混凝土性能，检测混凝土的抗裂性能。模型施工历时18d。     

PP改性纤维在水泥混凝土路面中的应用研究

介绍了ＰＰ改性纤维混凝土的有关性能实验，在水泥混凝土中掺加ＰＰ改性纤维后，混凝土抗弯拉强度、抗裂性等有了较大提高。在路面混凝土施工中掺入ＰＰ改性纤维后，混凝土拌合物的施工性能良好，抗弯拉强度在５．５～６．２ＭＰａ之间，满足设计要求。     

浅谈混凝土施工中质量的控制

近年来，随着城市建设的发展，高层、超高层钢筋混凝土建筑大量涌现，混凝土施工中的质量问题亦突出的显现出来。混凝土质量的好坏．关系到建筑物及构筑物的结构安全，关系到千家万户的生命财产安全。因此，解决常见的混凝土质量问题，在施工过程中对混凝土的施工进行综合控制．是不可忽视的问题。本文根据多年来的工作经验，结合工程中的现实问题，分析了混凝土施工中容易出现的质量问题的原因及施工中应注意的事项。     

混凝土保护层在设计施工中的问题探讨

混凝土保护层直接关系到混凝土结构的耐久性，以往的结构设计和施工中考虑强度多而考虑耐久性少，轻视混凝土保护层的设计和施工。针对上述问题．对混凝土保护层在设计、施工中应注意的几个问题做了简要分析。强调指出，只有严格按有关技术条款和规范进行混凝土保护层的设计和施工，才能确保混凝土结构的耐久性。     

浅谈控制沥青混凝土路面施工质量的几个要点

沥青混凝土面层具有良好的力学性能和耐久性以及行车舒适性，适合于各种车辆的通行，并具有表面平整、坚实、无接缝、行车舒适、耐磨、噪声低、施工期短、养护维修简便，适宜于分期修建等优点，因此得到了广泛的应用。通过多年的沥青混凝土路面施工，积累了一定的经验．在此对沥青混凝土路面施工质量的控制要点进行探讨。1．沥青混凝土路面原材料准备在沥青混凝土路面工程施工的准备阶段，原材料的质量检查应当是质量控制工作的主要内容，因为原材料的质量是影响沥青混凝土路面质量的根本因素。同时，对石料、矿粉的选定还须考虑到采石场的产量。沥青混凝土路面施工具有大规模、机械化施工的特点，日生产量大，如果因为原材料的供应不足而影响施工日进度，这实际也对沥青混凝土路面的质量造成影响。     

加气混凝土应用中存在的问题与对策研究

加气混凝土作为一种新型的墙体填充材料，具有容重小、强度低、吸水率高、收缩性大等优点．目前，由于工程应用中存在空鼓、开裂、剥落和墙体收缩裂缝等施工质量问题，在很大程度上限制了加气混凝土材料的发展与应用．为此，应采取提高混凝土的表面性能，加强砂浆与加气混凝土的粘结等施工措施加以解决．     

沥青混凝土路面施工中需注意的问题

从沥青混凝土路面施工的全过程出发，对实际施工中的施工工序、施工工艺、质量保证进行了详细阐述．并针对施工中出现的问题提出了具体的处理措施。指出加强管理和组织施工，才能铺出高质量、高水平的沥青混凝土路面，创造成优良工程。     

关于钢筋混凝土框架结构施工中的质量控制问题

本文分析了钢筋混凝土框架结构施工中梁柱节点箍筋施工,混凝土强度等级．混凝土保护层厚度和混凝土施工质量控制等工艺中存在的质量问题，并提出了相应的控制措施，供广大工程技术人员参考.     

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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