LF钢水成分与温度控制模型

以钢水、渣、包衬为研究体系,建立了钢水成分与温度控制模型.温度控制精度在±3℃以内,在补加系数法的基础上考虑了合金的收得率,推导出合金添加计算公式,使计算精度进一步提高.     

运用主成分分析和深度神经网络预测钢包炉合金元素收得率的研究

钢包炉（ladle furnace,LF）精炼的核心任务之一是进行钢水合金化过程,以保证钢包到达连铸平台后满足钢水成分要求。钢水合金化也是较为复杂的物理化学反应过程,其不仅对钢水温度有影响,而且对钢水质量、合金料消耗量均有影响。因此,实现LF精炼过程中合金元素收得率的精准预测具有重要意义。本研究首先采用主成分分析法（principal component analysis,PCA）对模型输入变量进行处理,用于简化实际生产数据结构;然后,融合SGDM算法和L2正则化方法,构建了深度神经网络（deep neural network,DNN）;最后,采用主成分分析和深度神经网络相结合的方法,建立了合金元素收得率预测模型。结果表明,Si元素收得率命中率在±1%, ±3%和 ±5%误差范围内分别为54.0%、93.8%和98.8%;Mn元素收得率命中率在±1%, ±2%和 ±3%误差范围内分别为77.0%、96.3%和99.5%。此外,PCA–DNN模型的预测精度优于参考炉次法、多元线性回归模型、改进BP神经网络模型和DNN模型,有助于实现钢水成分的“窄窗口”控制。本研究中合金元素收得率预测模型的建立,也可为LF智能精炼合金化控制模型的开发提供支撑。     

硅钢钢水真空处理时的脱硫反应

硅钢钢水用部分钢水提升法(即D-H法)真空处理时有脱硫现象。在鞍钢钢厂生产实践中的进行的试验表明,硅钢钢水的硫的脱除不是如流行观点所说藉加入硅钙合金而达到。按钢水部份提升法操作条件所作的热化学计算结果,表明通常操作所加入的硅钙合金中的钙是钢水的冷却剂,而不是钢水的脱硫剂。取消硅钙合金后的真空处理生产实践结果(同时控制真空室内残余压力),钢水中硫的脱除量增加、提升次数减少、处理时间缩短、钢水温升增加。真空处理钢水时,硫的脱除是藉生成SiS气体而达到的。     

钢水用Al－Si合金终脱氧的探讨

钢水用Ａｌ－Ｓｉ合金终脱氧的探讨关于采用Ａｌ－Ｓｉ合金代替Ａｌ终脱氧的几点看法是：①Ａｌ－Ｓｉ合金熔点比较高，在钢水中保持固态时间长，受钢水急热产生内应力的爆发作用，有利于合金的钢水内部分散和脱氧；②Ａｌ－Ｓｉ合金是显微组织中Ｓｉ的初晶枝状α体，包围...     

用回归分析方法探讨氧气转炉炼钢终点命中率

本文对某钢厂氧气转炉炼钢的日常生产原始数据进行了回归分析,分别得出了反映终点钢水碳含量与终点钢水温度控制状况的氧耗增量与铁矿石增量的多元回归与逐步回归方程。并根据实际计算结果,提出了提高终点命中率的途径。     

转炉连铸区段精细化控制节能潜力研究

针对转炉连铸区段钢水温度和操作时间不同控制精度所蕴含节能潜力的问题,建立基于生产实践的钢水温度和操作时间精细化控制模型,提出相应的计划额外能耗和实绩额外能耗的概念和计算方法。并以某钢厂生产钢种SPHC-W的生产实绩数据为例,对目前钢水温度和操作时间控制水平的节能潜力进行计算,得到计划潜在温度损失为7.25 ℃,实绩潜在温度损失特征值为10.10 ℃。进一步分析,得知在现有控制水平下,温度控制精度提高1 ℃,实绩潜在温度损失特征值降低0.33 ℃,时间控制精度提高1 min,计划潜在温度损失降低1.76 ℃,实绩潜在温度损失降低1.62 ℃。     

RH-MFB精炼过程中钢水温度预测模型

建立了RH-MFB精炼过程中钢水温度的数学模型,通过Delphi程序计算了精炼过程中钢水的温度.结果表明,RH-MFB精炼开始阶段,钢水温度急剧下降,前10 min降温速率约为3℃·min-1,加Al吹氧、加合金和真空室内壁初始温度对钢水温度影响较大.采用该模型预测了精炼结束时刻的钢水温度,与生产中钢水温度平均误差在±5℃以内的占80%.     

模糊线性规划在转炉合金模型中的应用

转炉炼钢中需加入一定量合金以使钢水中元素含量达标 基于普通线性规划的转炉合金最小成本控制模型在解决元素含量严格约束问题时 ,可有效求出成本最低的合金配比 ,但在元素含量约束模糊化的情况下 ,原模型求得的结果并非最优 文章对利用模糊线性规划解决此类问题的可行性、有效性作了探讨 ,进行了以生产数据及工业现场过程计算机软硬件环境为背景的数字仿真 结果表明 ,模糊线性规划能够在保证钢水品质的同时 ,最大限度地降低投入合金成本 ,可在一定程度上改善普通线性规划合金模型的实用性 ,优化控制效果     

精炼技术在提高钢水质量方面的研究

系统分析了钢水中存在的非金属氧化夹杂物对于高锰合金钢辙叉的影响程度,对于采用稀土硅合金可以提高高锰合金钢性能方面进行了详细地阐述,把线状稀土硅合金和铝丝采取喂线吹氩方式进行了实验,结果表明,力学性能和金相组织都有所变化,从而达到了精炼钢水的目的.     

模糊线性规划在转炉合金模型中的应用

转炉炼钢中需加入一定量合金以使钢水中元素含量达标，基于普通线性规划的转炉合金最小成本控制模型在解决元素含量严格约束问题时，可有效求出成本最低的合金配比，但在元素含量的约束模糊化的情况下，原模型求得的结果并非最优。文章对利用模糊线性规划解决此类问题的可行性，有效性作了探讨，进行了以生产数据及工业现场过程计算机软硬件环境为背景的数字仿真，结果表明，模糊线性规划能够在保证钢水品质的同时，最大限度地降低投入合金成本，可在一定程度上改善普通线性规划合金模型的实用性，优化控制效果。     

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     

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

正~~     

Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has