高炉渣对钢渣改性的物理化学基础研究

钢渣用作建筑材料时,由于其中含有大量游离氧化钙(f-CaO),稳定性较差,通常需要改性钢渣以提高其稳定性、胶凝性.在对钢渣、高炉渣进行化学成分和矿物组成分析的基础上,对高炉渣改性钢渣的可能性进行了热力学计算,结果表明高炉渣中的SiO2与钢渣中f-CaO反应,生成胶凝相,同时降低了钢渣中的f-CaO含量.本文通过研究热态高炉渣改性钢渣,结合X射线衍射、拉曼光谱、扫描电镜及能谱分析等研究方法,对改性钢渣的矿物成分、f-CaO含量、黏度变化等进行了分析.研究发现随着热态高炉渣配比量的增加,改性渣黏度缓慢增加,改性钢渣中f-CaO、RO相含量降低,改性渣的胶凝性能提高.在1550℃下,钢渣中添加10%高炉渣时,改性渣中2CaO·SiO2(C2S)、3CaO·SiO2(C3S)含量显著提高,f-CaO质量分数降至1.64%,稳定性大大提高,符合建材化使用要求.此外,进一步使用焦炭还原改性渣中的铁,轻松实现了渣铁分离,提高改性渣的易磨性.     

煤基固废复合改性剂高温重构钢渣的性能及机理研究

为了促进钢渣和煤基固废的综合利用,研究了煤基固废复合改性剂(CMCSR)(煤气化渣-硅钙渣-煤田区域水库底泥)对高温重构钢渣的胶凝性能和体积稳定性的影响,采用XRD、SEM、EDS等测试方法,对重构钢渣的物相组成、微观结构及高温重构机理进行了分析。发现CMCSR可以提高钢渣的胶凝性能,显著降低了钢渣中f-CaO含量。当重构温度为1250℃,CMCSR掺量为25%时,重构钢渣28d活性指数比原钢渣可提高16.1%,重构钢渣中f-CaO的含量由4.04%降至1.90%,满足GB/T20491-2017《用于水泥和混凝土中的钢渣粉》中f-CaO含量≤3%的要求。CMCSR掺量由15%增加至35%,重构钢渣中形成透辉石(CMS₂)、钙铝黄长石(C₂AS)、C₃A等硅铝基矿物。高温重构过程促使RO相中的FeO转变为镁铁尖晶石(MgFe₂O₄)和磁铁矿(Fe₃O₄)。重构温度为1250℃,掺25% CMCSC的重构钢渣形成结晶良好、粒径可达10μm以上椭圆形的C₂S颗粒。研究表明,掺入煤基固废复合改性剂的高温改性钢渣,其体积稳定性、胶凝活性和易磨性得到了有效改善,从而为钢渣的低能耗细磨加工进行制品开发,或在水泥和混凝土中的直接应用提供了可能,实现了煤基固废与冶金固废的协同利用。     

钢渣粉和钢渣水泥的活性及水化机理研究

利用X射线衍射分析、扫描电子显微镜、化学结合水量测定以及胶砂实验等方法研究了钢渣粉和钢渣水泥复合粉的活性和水化机理,研究结果表明:钢渣硬化浆体中的矿物组成含有水化产物C-S-H凝胶和Ca(OH)2,钢渣残余矿物C2F、Ca2(Fe,Al)2O5、CaCO3和RO相,和一些未反应的胶凝矿物C2S和C3S;钢渣、水泥和钢渣-水泥浆体三者的水化产物种类类似,微观结构形貌存在差异;14 d后掺钢渣水泥净浆试样的化学结合水量与水泥差距缩小,28 d后化学结合水量实测值大于计算值;钢渣掺量(质量分数)小于30%时,钢渣水泥胶砂的28 d强度高于水泥胶砂的28 d强度。     

碱激发钢渣矿渣胶凝材料凝结硬化性能研究

通过对胶凝材料强度、水化热的测定和对水化产物种类及表观形貌的分析,探讨了缓凝剂和钢渣掺量对碱激发钢渣矿渣胶凝材料性能的影响,并对其水化特性进行了研究.结果表明:钢渣掺量为40%、矿渣掺量为60%时,外掺6%水玻璃激发剂和1%的K缓凝剂,所制得的胶凝材料的凝结时间和强度可以达到42.5R普通硅酸盐水泥的技术要求;碱激发钢渣矿渣胶凝材料的放热特性与碱激发矿渣胶凝材料类似,具有放热量小的特点;钢渣与矿渣组合有利于胶凝体系水化进程的发展,两者具有相互促进的作用.     

石灰重构钢渣过程中的物相变化

以石灰作为单一调节材料高温重构钢渣,利用X射线衍射、岩相分析、扫描电子显微镜研究了重构过程中钢渣的矿物组成及RO相的变化,并测定了重构钢渣的安定性和活性指数.结果表明:RO相在CaO作用下优先发生分解反应,其中的FeO随CaO掺量增加依次生成Fe3O4、CF(铁酸一钙)、C2F(铁酸二钙)及Ca2(AlFe)O5(铁铝酸钙)、C4AF(铁铝酸四钙),其中的MgO部分以MgO晶体存在,部分固溶在硅酸盐相和液相中;当CaO/SiO_2摩尔比不够大时,原钢渣中的C3S(硅酸三钙)在重构过程中分解成C2S(硅酸二钙);由于CaO优先与含量较高的铁元素反应,CaO/SiO2摩尔比达到3时仍没有C3S生成,只有当与铁反应完全后多余的CaO才会与C2S反应生成C3S;石灰重构钢渣不会产生安定性不良且胶凝活性明显提高.     

高硅型铁尾矿对混凝土碳化及抗硫酸盐腐蚀性能的影响

将某高硅型铁尾矿进行机械力化学活化,将其作为辅助胶凝材料部分取代水泥制备混凝土,取代量(质量分数)分别为10%,20%,30%及40%,开展高硅型铁尾矿对混凝土碳化及抗硫酸盐腐蚀性能影响的试验研究.结果表明,掺加尾矿的混凝土抗碳化性能低于基准混凝土,随着取代量的增加,混凝土抗碳化性能呈下降趋势,但能满足混凝土结构工程的实际要求;随着取代量的增加,混凝土抗硫酸盐腐蚀性能呈上升趋势,取代量为20%,30%及40%时,混凝土抗硫酸盐腐蚀性能优于基准混凝土.经过机械力化学活化,某高硅型铁尾矿作为混凝土辅助胶凝材料部分取代水泥制备混凝土,就混凝土抗碳化性能及抗硫酸盐腐蚀性能而言是可行的.     

改性脱硫灰掺加矿渣粉煤灰制备生态型胶凝材料

分析了钢铁企业产生的脱硫灰的特性,通过实验进行了改性脱硫灰掺加矿渣粉煤灰等固体废弃物制备生态型胶凝材料的研究。研究结果表明：钢铁企业烧结工序产生的脱硫灰经高温改性后在制备胶凝材料过程中起到了替代石膏的作用;实验最优配比（质量分数）为粉煤灰4％、改性灰159／6、熟料18％、矿渣61％,再适当地辅以掺加激发剂和减水剂,可获得性能良好的具有较高强度的胶凝材料。     

化学-机械耦合效应对铁尾矿粉胶凝活性的影响

采用CaSO_4·2H_2O为活化剂,粉磨2.0h的铁尾矿粉具有火山灰活性.当其掺量为0.5%时,7d、28d活性指数与抗折强度比为最大,最大程度激发了铁尾矿粉的胶凝活性.并采用红外光谱法与微量热法研究了活化机理,研究结论表明:在化学-机械耦合作用下,铁尾矿粉中无序物质增多;而且该铁尾矿粉的掺加促进了水泥铝相的二次水化,显著提高了胶凝活性.     

钢渣-水泥复合胶凝材料的水化放热和动力学研究

通过测定钢渣掺量（质量分数）分别为0、20%、30%、40%的水泥基复合胶凝材料的水化放热速率,根据Krstulovi?-Dabi?动力学模型得到几何晶体生长指数n、反应速率常数K、各阶段转换时的水化度α,进而研究钢渣掺量对钢渣水泥复合胶凝材料水化放热与动力学的影响。结果表明：随着钢渣掺量的增加,各阶段水化放热速率变化趋势不同,钢渣掺量30%和40%时,出现第3放热峰,水化放热量随着钢渣掺量的增加而降低;钢渣掺量0、20%、30%时,水化历程由结晶成核与晶体生长(NG)到相边界反应(I)再到扩散过程(D);钢渣掺量40%时,模拟曲线偏离实际水化速率曲线,水化过程不符合Krstulovi?-Dabi?动力学模型;钢渣掺量0~30%范围内KNG、KI、KD均随着钢渣掺量的增加而降低;相对于钢渣掺量20%试样而言,纯水泥与钢渣掺量30%试样的I过程水化度范围较大;钢渣掺量0~30%的试样,水化12h已经成型,然而相同条件下,钢渣掺量40%的试样仍然不能硬化成型。为避免水化速率过低,钢渣最大掺量应为30%。     

基于混料实验研究矿物外加剂对氯氧镁水泥性能的影响

目的研究矿物外加剂对氯氧镁水泥(简称镁水泥)强度和耐水性的影响,以解决镁水泥耐水性差、浸水后强度严重损失的问题.方法以粉煤灰、硅灰和铁尾矿为矿物外加剂,利用SEM和XRD观察分析改性后的镁水泥的微观结构和相组成;运用单纯形重心混料设计分析矿物外加剂复掺对镁水泥抗压强度和软化系数的影响;通过回归模型分析矿物外加剂对MgO-MgCl_2-H_2O三元体系抗压强度和软化系数影响的显著性.结果随着粉煤灰掺量的增加,镁水泥的抗压强度逐渐降低,软化系数逐渐提高;随着硅灰掺量的增加,镁水泥抗压强度逐渐降低,软化系数先升高后降低,当硅灰掺量为15%时,软化系数为0.85;随着铁尾矿掺量的增加,镁水泥抗压强度基本保持不变,软化系数降低;当m(粉煤灰)∶m(硅灰)=0.51∶0.49时,镁水泥抗压强度为39.99 MPa,软化系数为0.73.结论矿物外加剂能有效地改善镁水泥的耐水性,提高软化系数;矿物外加剂对镁水泥的改性机理基本相同;混料设计能够有效的分析复掺条件下各组分对镁水泥性能的影响.     

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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