转炉煤气制备碳化铁的基础研究

根据热力学分析结果，在550～700℃范围内选择相应条件进行转炉煤气还原铁矿石的实验，研究温度及时间对碳化铁生成率的影响，并论述二者对于还原、析碳的影响，探索利用转炉煤气还原铁矿石生产碳化铁的可行性。     

气体种类对煤制气制备碳化铁的影响

主要研究了以煤制气为还原剂制备碳化铁过程中气体种类对还原度、金属化率、碳化铁率的影响.研究结果表明:CO+CO2混合气体还原铁矿石可以生成碳化铁,随CO/CO2比值的增加碳化铁率也增加;还原气体中氢气的含量在10%～20 %范围为宜.     

气体种类对煤制气制备碳化铁的影响

主要研究了以煤制气为还原剂制备碳化铁过程中气体种类对还原度，金属化率，碳化铁率的影响，研究结果表明：CO＋CO2混合气体还原铁矿石可以生成碳化铁，随CO／CO2比值的增加碳化铁率也增加，还原气体中氢气的含量在10％－20％范围为宜。     

Fe_3C生成机理及物相分析

在热力学计算的基础上,探讨了铁矿石在流化床内还原生产Fe3C的生成机理和途径·结果表明,700℃时铁氧化物还原符合逐级还原理论,碳化铁由生成的铁经CO渗碳得到;反应温度介于586℃和628℃之间,碳化铁主要由反应产生的FeO与CO反应得到,另一部分碳化铁由矿石中还原出的金属铁与CO反应得到;温度低于586℃时,产物中的碳化铁主要由Fe3O4与CO反应得到,产物中磁铁矿含量较高·同时利用穆斯堡尔谱和X衍射分析手段验证了产物中碳化铁的存在,所有这些研究成果为Fe3C的工业化生产提供理论基础·     

炉顶煤气循环氧气高炉一维气固换热与反应动力学模型

结合风口回旋区燃烧和炉外煤气预热、脱除和循环的平衡关系,建立了氧气高炉一维气固换热与反应动力学模型,并采用传统高炉的运行和解剖数据对模型进行了验证分析.通过模型研究了氧气含量和上部循环煤气流量对氧气高炉炉内过程变量的影响规律.结果表明：氧气含量偏低和上部循环煤气流量不足时,会降低铁矿石还原效果,炉渣内出现大量未还原铁氧化物;氧气含量和上部循环煤气流量的提高可以有效提高炉内CO含量和铁矿石还原速度,但提高上部循环煤气流量会大幅提升炉顶煤气温度,增大热量损失.与传统高炉相比,氧气高炉内CO含量提高1.0~1.5倍,炉内气体还原性更强;铁矿石还原完成位置提高1.49 m,全炉还原反应速度更快;直接还原度降低55.2%~79.2%,炉内直接还原反应消耗的碳量更少.     

重点钢铁厂铁矿石还原及焦炭气化的藕合反应

通过在模拟高炉温度和煤气成分变化的条下,对我国重点钢铁厂铁矿石还原及焦炭气化的藕合反应研究,阐明了焦炭气化与铁矿石还原与反应历程有关。分析预测高炉冶炼效果除考虑恒定温度和恒定煤气成分下焦炭与铁矿石冶金性能外,还应考虑焦炭与铁矿石藕合反应过程CO过剩量。研究表明宝钢、首钢、本钢、鞍钢CO过剩系数ηc较小,煤气利用好;包钢、重钢和梅山冶金公司ηco较大,煤气利用较差。     

温度对煤造气制备碳化铁的影响

研究了以煤造气为还原剂制备碳化铁过程中温度对还原度、金属化率、碳化铁率的影响,实验条件为压力0.3 MPa、反应时间180 min、还原气体中CO/CO2分别为3和1.5,反应温度在550～700℃之间变化.通过实验研究得到如下结论:产物的还原度、金属化率随温度的升高而逐渐增大;碳化铁率在600℃时最小;在气体成分达到一定还原势(CO/CO2=3)的条件下,700℃时碳化铁率最高;而在CO/CO2=1.5时,高温下不利于碳化铁的生成.     

铁矿石在回转窑和固定床中还原速度式的推导与分析

导出并分析了铁矿石在回转窑和固定床中的还原速度式,确定了加快还原速度的条件,并提出提高煤气利用率的措施。     

温度对煤造气制备碳化铁的影响

研究了以煤造气为还原剂制备碳化铁过程中温度对还原度、金属化率、碳化铁率的影响，实验条件为压力0.3MPa、反应时间180min、还原气体中CO／CO2分别为3和1.5，反应温度在550－700℃之间变化。通过实验研究得到如下结论：产物的还原度、金属化率随温度的升高而逐渐增大；碳化铁率在600℃时最小；在气体成分达到一定还原势（CO/CO2=3)的条件下，700℃时碳化铁率最高；而在CO／CO2=1.5时，高温下不利于碳化铁的生成。     

利用催化剂促进碳化铁生成速度的基础性研究

传统的碳化铁生产工艺存在反应时间较长的难题,为此通过在流化床入炉矿石中配加部分添加剂的还原实验研究,以寻求该反应可能的催化剂,缩短反应时间,提高碳化铁生产效率和经济效益·采用CaCl2和K2CO3作为反应的催化剂,利用反应所测数据,与对比实验相比较,并结合动力学分析,得出CaCl2和K2CO3可以加速碳化铁还原反应进行的结论·     

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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