轧钢加热炉改造

针对轧钢加热炉加热能力不足,炉墙冒火,自动化控制水平落后的情况,对加热炉进行了改造,延长了加热炉的长度,更换了单蓄热式空气烧嘴,并对自动控制系统进行了升级改造,从而消除了炉墙冒火的现象,提高了加热能力和自动控制水平,降低了煤气消耗,取得了良好的经济效益。     

TRT顶压控制系统及其安全性的研究与优化

介绍了天钢1~#TRT顶压控制系统,对现有的顶压控制系统进行了分析,在原有差压调节模式的基础上增加了顶压调节模式,将实际操作改为差压调节与顶压调节两种互选模式,提高了系统的发电效率;对旁通阀组的控制进行了优化,优化后极大地提高了系统的安全性,保证了炉顶压力的稳定,延长了设备的使用寿命,产生了较高的经济效益。     

浅议矿脉变化规律与探矿方法

概要介绍了樟东坑矿区的主要地质特征,在前人工作的基础上,对矿床的基本特征(尤其是矿脉的变化特征)进行了分析、探讨和总结;利用这些特性及其变化规律,采用一些新的探矿方法不但找到了一些隐伏盲矿,增加了地质储量,延长了矿山的服务年限,而且降低了探矿费用,减少了采矿的盲目性,节约了成本,增加了经济效益。     

工业机器人在鞍钢型钢生产线的设计与应用

根据鞍钢股份有限公司型钢生产线工艺实际,制定了机器人硬件设计方案和机器人软件实现方案,实现了工业机器人自动贴标喷码技术在型钢生产线的应用.该系统的应用满足了产线工艺要求,提升了产线生产效率,提高了产品标识的准确性和可追溯性,贴标准确率和喷码准确率均达到了99％,实现了危险岗位无人作业,作业周期缩短了25％;同时,实现了产品标识的统一规范性,提升了企业产品形象.     

RTK和全站仪联合采集数据模式在安钢GIS中的应用

介绍了RTK和全站仪联合采集数据模式在安钢GIS中的应用情况,通过两种测绘技术的优势互补,简化了程序,提高了效率,减少了误筹,保证了测绘精度,节省了人力和物力.     

废水处理站自动控制系统的应用

介绍了邯钢冷轧废水站的配套项目废水处理站的自动控制系统,主要从自控设备组成、网络控制系统等方面论述了控制功能的实现,该系统的应用为ERP的数据采集提供了很好的保证,提高了电气控制的集成度和可靠性,简化了控制环节,提高了生产效率.     

提高转炉护炉效果的实践

从转炉耐材的损害机理入手,分析了耐材的损耗机理,探讨了炉渣的优化机制,对炉渣的组成及渣料的使用进行优化,对溅渣的工艺进行了改进,实现了转炉护炉的提升,延长了转炉的使用寿命,降低了耐材的损耗,降低了转炉工序的成本。     

采用Boost技术优化企业数据备份保护架构

为了解决大型制造企业数据中心架构变更后,在数据保护方面所面临的多种难题,对适用的数据保护技术进行了研究探讨.最终实现了企业数据保护平台架构的转型升级,提升了平台自身的安全性,改善了备份数据的传输架构,备份效率提升了10倍以上.实现了备份任务的集中智能管理,节约了备份窗口,实现了备份资源的一次性分配与自动回收,释放了备份...     

ACS6000SD变频器在粗轧机主传动系统中的应用

济钢中厚板厂3500线粗轧机改造主传动系统采用ACS6000SD变频驱动系统,系统的整流侧和逆变侧采用了对称结构,降低了维护难度;采用了IGCT技术,保证了系统的性能响应;使用了DTC技术,提高了系统的鲁棒性。这种交直交系统做到了对电网的最少谐波运行,既减少了对电网的污染,又省去了无功补偿系统的投资。     

镁挤压工业及技术发展概况与趋势

经过近20年的快速发展,我国镁挤压工业与技术获得了跨越式进步,不仅兴建了一批现代化的镁挤压企业,投产了一批3600t左右的现代化镁合金挤压机及其配套设备,而且开发了大批新技术、新工艺和新产品,大幅度降低了生产成本和提高了生产效率,拓展了应用领域,成为世界镁挤压大国。本文详细阐述了挤压成形在轻合金材料加工中的重要地位,指出热挤压成形是镁及镁合金材料最重要的加工方法,介绍了国内外镁挤压工业及技术的发展概况与趋势。     

Redox Properties of Gas Phases

In the H₂–O₂–C system, in the general case, two reversible reactions of carbon gasification and the water gas reaction, the gas mixture H₂–H₂O–CO–CO₂ is formed at high temperatures. In this mixture, the very low content of oxygen formed by the dissociation of H₂O and CO₂ is represented by the oxygen potential log (\({p_{{O_2}}}\), atm). Thus, the redox properties may be assessed in terms of the oxygen potential. In any gas mixture containing H₂O and/or CO₂, it may be calculated from the equations

$${\log [{p_{{O_2}}},atm] = 2\log (\frac{{{x_{{H_2}O}}}}{{{x_{{H_2}}}}}) - \frac{{25708}}{T} + 5.563}$$

;

$$\log [{p_{{O_2}}},atm] = 2\log (\frac{{{x_{C{O_2}}}}}{{{x_{CO}}}}) - \frac{{29529}}{T} + 9.149$$

.In the present work, possible compositions of the H₂–O₂–C system at 700–1500 K and a total pressure of 1 atm are considered: H₂–H₂O, CO–CO₂, CO–CO₂–C, H₂O–CO₂–O2, H₂–CO–C, H₂–H₂O–CO–CO₂, and H₂–H₂O–CO–CO₂–C. Analysis yields two nomograms in the following coordinates: log(\({x_{{H_2}O}}\)/\({x_{{H_2}}}\))–log\({p_{{O_2}}}\)–T and log(\({x_{C{O_2}}}\)/xCO)–log\({p_{{O_2}}}\)–T. Using the nomograms and reference information regarding the dissociation pressure of metal oxides, the redox properties of the gas mixtures with respect to those oxides may be assessed. In CO–CO₂ systems without hydrogen that are obtained in the combustion of CO, carbon may be formed as soot. This explains the existence of a limited region of gas-phase compositions and log\({p_{{O_2}}}\) in the corresponding nomogram and hence the limited potential for the reduction of some metal oxides in CO–CO₂–C systems. The introduction of hydrogen permits the creation of gas mixtures with extremely low oxygen pressure and hence increases the thermodynamic probability of reduction for any metal oxide. Hydrogen may be introduced in the system by methods that differ in economic expediency: from the use of pure hydrogen to the production of gas mixtures as a result of the reaction between water vapor and carbon. In the first case, the reduction of the oxide by hydrogen in the MeO–C–H₂ system activates the gasification of carbon by water vapor, the water gas reaction, the reduction of carbon monoxide, and the gasification of carbon dioxide. In the second case, practically pure H₂–CO mixture may be obtained above 1300 K. The utility of representing the results on a three-dimensional diagram based on the H₂–O₂–C concentration triangle is analyzed. If methane formation is taken into account, the equilibrium parameters of gas mixtures are changed markedly only at temperatures below about 900 K.

     

Cementitious Phases in Ladle Slag

Ladle slag is an internal by‐product generated within the steelmaking industry during the refining of steel. The realisation of beneficial inherent properties of ladle slag as a binder supplement or substitute material is believed to be advantageous with respect to both economy and environment for steelmakers. For this reason, the current study has focused on highlighting the properties of ladle slag that are pertinent to the formation of calcium aluminate hydrates. Three fractions of ladle slag, two of which were based on different slag formers, have been characterised using XRF, XRD and calorimetric analysis. Commonly known hydraulic minerals such as mayenite, tricalcium aluminate and dicalcium silicate were detected during analysis. An important aspect in the utilisation of ladle slag is the slag handling methodology. Therefore, this study also highlights and discusses the need to reconsider slag handling procedures concerning unnecessary exposure to weathering and the possible need for further processing of the slag in order to better employ the inherent hydraulic properties of this material.     

Phases and phase transitions of the phosphatidylcholines

LIPIDAT (http://www.lipidat.chemistry.ohio-state.edu) is an Internet accessible, computerized relational database providing access to the wealth of information scattered throughout the literature concerning synthetic and biologically derived polar lipid polymorphic and mesomorphic phase behavior and molecular structures. Here, a review of the data subset referring to phosphatidylcholines is presented together with an analysis of these data. This subset represents ca. 60% of all LIPIDAT records. It includes data collected over a 43-year period and consists of 12,208 records obtained from 1573 articles in 106 different journals. An analysis of the data in the subset identifies trends in phosphatidylcholine phase behavior reflecting changes in lipid chain length, unsaturation (number, isomeric type and position of double bonds), asymmetry and branching, type of chain-glycerol linkage (ester, ether, amide), position of chain attachment to the glycerol backbone (1,2- vs. 1,3-) and head group modification. Also included is a summary of the data concerning the effect of pressure, pH, stereochemical purity, and different additives such as salts, saccharides, amino acids and alcohols, on phosphatidylcholine phase behavior. Information on the phase behavior of biologically derived phosphatidylcholines is also presented. This review includes 651 references.     

Precipitation of Second Phases in High-Interstitial-Alloyed Austenitic Steel

The precipitation reaction of an austenitic stainless steel containing N + C was investigated using transmission electron microscopy. The main precipitate formed during isothermal aging at 1123 K (850 °C) was M₂₃C₆ carbide, and its morphology gradually changed in a sequence of intergranular (along grain boundary) → cellular (or discontinuous) → intragranular (within grain interior) form with aging time. Irrespective of different morphologies, the M₂₃C₆ was consistently related to austenite matrix in accordance with the cube-on-cube orientation relationship. Based on the analysis of electron diffraction, two variants of intragranular M₂₃C₆ were identified, and they were related to each other by twin relation. Prolonged aging produced other types of precipitates—the rod-shaped Cr₂N and the coarse irregular intermetallic sigma phase. The similarities and differences in precipitation behavior between N only and N + C alloyed austenitic stainless steels are briefly discussed.     

Entropy of Alloy Phases: A Macroscopic Perspective

This study presents a comprehensive analysis of the entropy of condensed phases, its temperature, pressure, and composition dependence on a macroscopic correlative platform. Two principal contributions to total nonconfiguration entropy (S_T) are outlined. They are: (i) the pure thermal (S_th) contribution arising from the isochoric temperature dependence of Gibbs energy (G_T) and (ii) the elastic contribution (S_el) representing the dilatational volume effects. It is then argued that entropy variation among a group of alloy phases can be exclusively related to molar volume, only when both thermal pressure (p_th) and thermal entropy terms assume common values for all members. This argument is extended to establish a linear relationship between transformation entropy (ΔS_tr) and transformation-induced volumetric strain (ΔV_tr/V). The temperature and pressure dependencies of entropy have been discussed in terms of the complementing roles of S_th and S_el and simple approximations to these effects are suggested. A macroscopic power law relation for systematizing the standard entropy variation using a composite scaling parameter (MV^2/3/T_m) has been proposed, and its validity is demonstrated for both solid and liquid metals. This power law correlation has been exploited to deduce the following outcome: (i) a simple approximation for the initial slope (dp/dT_m) of p–T_m melting curve, (ii) self-consistent correlation of entropy with specific heat and Debye temperature, (iii) estimation of entropy of metastable phases, and (iv) correlating dilute solution entropy with volume effects of alloying.

     

关于我国现代教育发展阶段问题的探讨

清晰定位当前我国教育发展所处的具体历史阶段,准确把握现阶段的主要矛盾,是我国教育改革与发展的现实要求.与人类教育发展的一般历程相近,我国教育发展经历了古代教育与现代教育两个大阶段.清末"兴学校""废科举"是我国教育从古代教育演化为现代教育的基本标志.20世纪以来我国教育的发展探索,是不断确立完善中国现代教育体系的实践过程.我国现代教育百余年的发展历程,依据教育发展主要矛盾的变化,可以区分为体系创建、规模扩张、质量提升三个基本阶段.当前,我国教育发展正处在由规模扩张阶段向质量提升阶段过渡的特殊时期,为迎接质量提升时代到来而精心准备,是当前教育理论与实践探索的共同使命.     

碳热还原辉钼矿过程的物相变化规律研究

通过X衍射分析法研究了碳热还原辉钼矿过程的物相变化规律。不使用还原剂直接用CaO处理辉钼矿反应的最终产物为:CaS、Ca MoO4、Ca5Mo18O29和Mo;该反应过程中会出现Ca Mo6S8相,但在1 100℃下加热6 h时,Ca Mo6S8基本消失。使用炭粉作还原剂时,炭粉还原钼的中间产物由易至难的顺序为:Ca MoO4、Ca5Mo18O29和Ca Mo6S8;当温度≤1 150℃,炭粉配比小于4.0时的最终产物物相是Mo和CaS;当温度为1 150℃,炭粉配比为6.0时产物有少量的Mo2C生成。