精炼渣中FeO的活度模型

根据熔渣结构的分子离子共存理论,建立了SiO2-Al2O3-CaO-MgO-FeO-MnO六元渣系的活度计算模型。计算得到了LF精炼渣中FeO的活度值,并分析了炉渣成分Al2O3、FeO以及碱度w(CaO)/w(SiO2)对FeO活度的影响,为帘线钢精炼变渣过程中控制回硫提供指导。     

FeO含量对SiO2-CaO-Al2O3-MgO(-FeO)酸性渣熔化温度的影响

基于熔渣离子理论,利用导电法在高纯氩气保护下测定SiO2-CaO-Al2O3-MgO(-FeO)酸性渣(二元碱度R=0.6)的熔化温度,考察FeO含量对酸性渣熔化温度的影响。结果表明,FeO的加入可以降低酸性母渣SiO2-CaO-Al2O3-MgO的熔化温度,且渣中FeO含量越大,渣样熔化温度越低;当渣中FeO含量低于20%时,随着FeO含量的增加,渣样熔化温度降低幅度较大;当渣中FeO含量高于20%时,随着FeO含量的增加,酸性渣熔化温度降低趋势变缓。     

基于FactSage计算优化转炉脱磷工艺的基础研究

本文将脱磷理论与FactSage软件相结合进行模拟计算,研究CaO、SiO2、P2O5、MgO和FeO含量对熔化性温度的影响,并通过单因素分析、正交实验分析、方差分析和相图分析等找到最佳渣系含量组合. 实验结果表明,SiO2含量增加使熔化性温度降低,CaO含量的增加使熔化温度上升,MgO含量在3%~7.5%之间时完全熔化温度下降,P2O5含量的升高会降低熔化温度;CaO对开始熔化温度影响最大,SiO2和FeO对完全熔化温度影响最大. 开始熔化温度最低, 各因子的最低值为：CaO=26%、SiO2=24%、FeO=21%、P2O5=9.8%、MgO=9%;完全熔化温度最低, 各因子的最低值为：CaO=38%、SiO2=22.5%、FeO=18%、P2O5=5.3%、MgO=3%. 通过分析CaO含量对FeO-SiO2-P2O5相图、FeO含量对CaO-SiO2-P2O5相图以及SiO2含量对CaO-FeO-P2O5相图液相区的影响,我们发现随着CaO含量的增加,FeO-SiO2-P2O5体系中液相区温度升高,其中1800 ℃液相区扩大;FeO含量对CaO-SiO2-P2O5体系液相区影响较明显,尤其在15%~18%的FeO含量范围,1600 ℃温度区间不断扩大,并且增加了1400 ℃与1600 ℃温度区间;SiO2含量的增加使CaO-FeO-P2O5体系的液相区减小,即体系的熔化性温度升高,从而使得渣中P2O5的含量降低,有利于脱磷.     

由FeO—V2O3和V2O3-SiO2二元相图提取活度

本文研究了在正规溶液的假设下,运用由二元相图提取活度的方法,分别计算了FeO—V2O3和V2O3-SiO2渣系相图在2500K温度下的活度。经加权平均计算,计算值和实验值的相对误差分别为13．34％和6．5％．这个精度处于Turkdogan提出的10％-30％的实验误差范围以内,可以作为进一步研究复杂含钒渣系时的热力学参考数据。     

锰在渣/钢之间分配平衡的热力学评估

对不同研究者获得的锰在渣/钢之间分配平衡的相关热力学数据进行了归纳和评估.结果表明,在温度为1 873 K下, 对组成为 (0.2%～36.8%)CaO-(4.0%～69.7%)FetO-(7.5%～31.0%)SiO2-(6.7%～25.0%)MgO-(0.5%～3.4%)P2O5-(3.4%～16.0%)MnO的炼钢渣,利用聚集电子相模型和经验公式计算MnO的活度与实验测定值相吻合,MnO的活度值为0.02～0.20,用正规溶液模型计算的结果低于实验测定值.MnO的活度受渣中FetO含量的影响不明显,随渣中MnO含量和渣碱度的增加而增大.在误差为±20%的范围内,可用经验公式和聚集电子相模型来预测与渣平衡钢中的锰含量.在炼钢温度下,碱度对锰的分配比影响较大,碱度相同的情况下,高FetO渣有较强的脱锰能力.在温度为1 623 K下,锰在渣/铁之间的分配比可以通过测定锰在渣/钢之间的分配比,再通过计算得到.     

焙烧温度对高铁提钒尾渣煤基直接还原效果的影响

利用X射线衍射(XRD)、扫描电镜(SEM)等手段考察了焙烧温度对提钒尾渣煤基直接还原效果的影响,并利用磨矿-磁选方法对焙烧产物进行了金属铁的分离实验.结果表明:最有利于金属铁析出、兼并、长大以及金属铁和渣相单体解离的焙烧温度是1200℃,在此温度下,提钒尾渣中的Fe2O3基本还原成了金属铁,Fe2TiO5基本转变成了金属铁和TiO2.铁质量分数36.54%、TiO2质量分数9.28%的提钒尾渣,经1200℃焙烧所得产物经过二段磨矿-二段磁选可获得铁质量分数90.90%、TiO2质量分数0.56%的金属铁粉.     

CaO-FeO-Fe2O3-SiO2-Cu2O渣系作用浓度计算模型

基于炉渣结构共存理论,建立1 523～1 733 K时的CaO-FeO-Fe2O3-SiO2-Cu2O五元渣系作用浓度计算模型,对成分(质量分数)波动范围为CaO 5%～20%,FeO 5%～50%,Cu2O 5%～25%,SiO2 5%～45%,Fe2O3 5%～70%的炉渣,计算1 523和1 573 K时的各组元作用浓度,考察碱度和温度对活度系数和的影响,并对所得数据进行非线性回归分析.研究结果表明,理论计算值与文献实测值之间的相对误差小于10%,且随渣含铜增加呈直线上升的趋势一致,说明模型能较好地反映本渣系的结构本质;CaO能降低炉渣的溶铜能力,增强炉渣的溶铁能力.该模型的建立为采用铁酸钙渣系的炼铜新工艺热力学研究提供了理论依据.     

LF炉合成精炼渣成分优化

通过建立二次回归正交设计模型,考察了合成精炼渣碱度w(CaO)/w(SiO2),Al2O3和CaF2质量分数对LF深脱硫效果的影响.结果表明,当渣中w(FeO)为0.5%,w(MgO)为9%时,随渣中w(CaO)/w(SiO2)增加,脱硫率均先增大后减小.当w(CaO)/w(SiO2)不同时,Al2O3和CaF2质量分数对脱硫效果的影响程度不同,主要原因是渣中有效CaO含量变化引起的.随渣中w(FeO)降低和渣量增加,脱硫率明显增大.实验优化的最佳脱硫渣系组成为w(CaO)/w(SiO2)=9~11,w(Al2O3)=27%~29%,w(MgO)=9%,w(CaF2)=8%~10%,w(FeO...     

低碳含铝钢20Mn2精炼渣系CaO-SiO2-Al2O3-MgO-CaF2的优化

通过对低碳含铝钢20Mn2精炼过程的取样分析,得出精炼渣的熔化温度偏高,渣中存在大量固相CaO,并导致钢中含有CaO类夹杂物,精炼渣吸附夹杂物能力差. 利用FactSage热力学计算,从渣的低熔点区域控制和渣-钢反应这两个方面对渣系进行研究与优化. 结果表明,CaO/Al2 O3 质量比在1. 5左右添加质量分数为3% CaF2 可以有效降低渣的熔化温度,渣的熔化温度随着CaF2 含量的升高呈现先降低后升高的趋势,MgO的质量分数控制5%左右低熔点区域面积达到最大. 在SiO2 质量分数大于30%区域,钢中氧含量大体上随着CaO/Al2 O3 质量比的增加而降低,在SiO2 的质量分数低于30%区域随着CaO含量的升高而降低,钢中酸溶铝含量在SiO2 含量高的区域随着Al2 O3/SiO2 质量比的增加而升高,在SiO2 含量低的区域随着CaO/SiO2 质量比的增加而增加. 根据热力学分析结果得出合理的渣系范围:CaO 50% ~60%, Al2 O3 20% ~35%, SiO2 5% ~10%, MgO 5% ~8%, CaF2 0~5%. 优化渣系的实验结果表明,优化后渣系熔化温度降低,钢中夹杂物数量、面积和平均尺寸均有明显下降.     

熔融态高钙高磷钒渣氧化钠化—水浸提钒

采用XRD对钠化高钙高磷钒渣(11.48%V2O3、13.71%Ca O、0.78%P2O5)熟料的物相组成进行了分析,并研究了钒渣熟料提钒的最佳实验参数。结果表明:在Na2CO3加入量相对较少时(35%),V存在于Na4V2O7、Na3VO4、Na1.33V2O5和Na Ca VO4中,随着Na2CO3加入量的增加,Na4V2O7和Na Ca VO4会进一步与Na2CO3反应转化为Na3VO4;钒渣熟料中P存在于水溶性Na3PO4中;当实验条件如下:Na2CO3加入量为40%,液固比为5∶1 m L/g,浸出温度为90℃,浸出时间为4min,搅拌速度为150 r/min,高钙高磷钒渣熟料浸出率可超过90%。可见,熔融态高钙高磷钒渣氧化钠化水浸提钒的方法可行。     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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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