连铸热坯表面温度可见光谱CCD辐射测温方法

针对连铸坯表面测温现状和存在的问题,建立了双色法(R、G)与单色法(B)相结合的实时测温模型.采用可见光面阵CCD图像传感器进行铸坯表面图像采集,实验研究了不同光圈(F)与积分时间下的R(红)、G(绿)、B(蓝)三基色值随温度的变化规律和动态响应区间.利用计算机图像处理技术建立了连铸热坯表面二维温度场与RGB的关联关系,实现了连铸热坯表面温度场的在线测量.通过控制CCD传感器光积分时间以提高CCD传感器的动态响应范围,为实现连铸坯表面温度场在线测量提供了理论基础和技术支撑.     

氩氧精炼生产中低碳铬铁炉内在线测温技术的试验与探讨

探讨了铁合金生产中在线测温的机理,在氩氧精炼工艺生产中低碳铬铁过程中,对AOD炉在线测温技术进行了工业试验,并根据试验结果,计算出了温度校验曲线,基本实现在线测温,对反应终点的控制及确保设备安全具有重要意义。     

基于CCD三波段发射率迭代的加热炉内温度场软测量研究

通过利用CCD成像R、G、B三个通道的维恩公式,建立非黑体的光谱辐射亮度之比与其温度之间的关系式。针对传统无线测温方式受到检测距离与特定温度的限制并且不适应高温、粉尘、强光等特殊环境的不足,提出了基于CCD三波段发射率迭代的加热炉内温度场软测量的方法。使得炉内高温CCD相机在成像的同时,可以得到炉膛以及板坯温度的实时检测值,极大的提升了CCD相机成像的检测效果和适应性。实践表明,检测结果在高温,粉尘、强光环境下也取得了理想的效果。     

加热炉板坯和炉围表面温度测量的辐射传热反问题的研究

本文构造了加热炉内辐射测温模型 ,并进行了辐射反问题的研究。研究表明 ,炉围表面温度对测量系统影响较大 ,在估计料坯表面温度的同时还需同时处理炉围表面温度。对不同类型的辐射测温计进行了比较分析计算。     

基于红外CCD热成像测温的加热炉钢坯温度场模型研究

将红外CCD热成像测温技术应用到加热炉钢坯表面温度测量,以直接测得的表面温度作为建立钢坯模型的边界条件,并以传热学为基础,建立了加热炉钢坯温度场模型。同时,应用现场数据对模型进行了验证,结果表明:该方法进一步提高了现行温度场模型测量精度,完全符合工业应用的要求。     

CCD逆流洗涤设备选型及计算方法

CCD逆流洗涤是一种重要的浓密分离洗涤工艺,广泛应用于湿法冶炼、选矿等行业.浓密机是CCD逆流洗涤的主要设备,它的选型的准确性决定了投资的大小及生产的稳定.本文介绍了浓密机的选型方法,并利用工艺过程模拟软件Metsim,对CCD逆流洗涤进行模拟计算,计算结果可应用于实际工程项目中,避免了繁琐的计算.     

热成像仪在热轧带钢温度均匀性评价上的应用实践

通过热成像仪在热轧带钢进入精轧机前对其进行测温,利用处理软件对热成像图数据进行分析,计算轧件宽度方向存在的边部温降值和边部温降区域的宽度值以及长度方向头尾位置的低温区长度和温降值。实现了对热轧带钢轧制过程的温度均匀性评价,为现场的在线测温提供了一种有效的补充手段。     

目标距离和视场角变化对红外热像仪测温精度影响的理论分析

红外热像仪进行测温时,目标距离和视场角变化,会大大降低测温精度.根据几何光学和红外目标辐射理论,推导出温度测量误差与目标距离和视场角之间的关系式,并结合研制的一套红外热像仅系统参数,计算了温度测量误差.提出了提高测温精度的方法,采用此方法,对相同条件下的物体测温,测量误差仅为-0.22℃,在很大程度上减小了目标距离和视场角变化对红外热像仪测温精度的影响.     

新型铁水预处理测温取样装置的研制

介绍了鞍钢第一炼钢厂铁水脱硫预处理工程中测温取样装置的结构和技术特点,并对升降传动机构电机减速机功率及测温取样枪的冷却氮气用量进行了计算。生产实践表明,该装置具有结构简单、安全可靠、使用寿命长、投资少等特点,该装置已在鞍钢其他厂推广应用。     

宣钢4号高炉停炉放残铁实践

对宣钢4号高炉停炉放残铁实践进行了总结,重点阐述了根据理论计算和炉壳测温拐点推算相结合确定残铁口位置的方法。为尽可能放净炉缸残铁,要根据高炉炉底耐材侵蚀厚度来确定残铁口的位置标高,实践表明,采用拉姆公式计算炉底侵蚀深度,计算结果较为准确可靠,与炉壳测温拐点推算的结果较接近。4号高炉放残铁方案制订周密可行,操作过程安全有序。     

Surface charges on membranes

The mesial rest-I-bar concept is the most important contribution to clasp partial denture design in the last 30 to 40 years. When used with discernment in situations where it is not contraindicated, it constitutes an excellent design for extension-base removable partial dentures. It has become the design of choice for an increasing number of dentists. Use of the three elements that make up the clasp assembly does not necessarily insure that the clasp will function as intended. There are situations for which it should not be used. Unless adequately adjusted after framework construction as well as during the maintenance program, the beneficial effects may be more imaginary than actual. Strict adherence to the mesial position for the rest is not rational for toothsupported dentures and may be questioned for some extension-base prostheses. I-bars have several advantages as direct retainers. However, no single type of retainer is applicable for all retentive situations, and other types should be selected where conditions are unfavorable for I-bar use. A framework which permits a slight amount of movement toward the edentulous residual ridge is an important consideration in design of extension-base removable partial dentures, particularly for those of the mandibular arch. However, compromise of this principle is sometimes necessary to satisfy other design requirements. Design of the framework is only one of the factors that contribute to a successful removable partial denture. Of at least equal importance is the adequacy of support provided by the denture base and the nature of the occlusion. If meticulous attention is directed to these two factors, the forces transmitted to the teeth through the framework can be kept to a minimum and within physiologic tolerance. Conversely, neglect of these considerations may cause a framework of any design to become destructive.     

光亮表面镀锡板及DI材的表面粗糙度试验研究

镀锡板表面粗糙度试验研究结果表明,生产光亮表面镀锡板时,提高平整辊粗糙度,可延长平整辊的使用寿命和提高原板的粗度,显著降低镀 锡板木纹、锡结晶、锡层及原反擦划伤等表面缺陷,并提高了镀锡板的使用性能,通过优化DI材平整辊配置,使DI材粗糙度得到稳定控制并养活了平整辊种类,提高了其利用率。     

Impact of Membrane Surface Modification on the Treatment of Surface Water

New polyethersulfone (PES) based membranes for ultrafiltration (UF) were developed by blending a surface-modifying macromolecule (SMM) in the casting solution, in an attempt to minimize the impact of fouling. Fouling was evaluated using concentrated Ottawa River water (CORW), either unfractionated or fractionated via UF. These membranes also included some polyvinylpyrrolidone (PVP), a pore forming additive. A statistical analysis was conducted to evaluate the impact of some variables on the treatment of the surface water. The independent variables included PVP/PES ratio in the casting solution, with and without SMM, and the nature of the feed CORW [low molecular weight (LMW) fraction, unfractionated, high molecular weight (HMW) fraction]. The performance variables studied were total organic carbon (TOC) removal, the foulant accumulation at the membrane surface after filtration, the flux reduction, and the final permeate flux. The most important variable was the feed water. Filtration of LMW had a higher final flux, less fouling, but slightly lower TOC removal. The SMM did not significantly impact the membrane performance. TOC removal was high, compared with results reported in the literature for UF membranes.     

Study on Surface Treatments on CdSe Wafers

The surface treatments on CdSe wafers were studied by means of SEM, XPS and micro-current test instrument. The relations between electrical properties of CdSe wafers and surface topography, composition and structure were analyzed. The results show that the change of surface composition by etching is beneficial to decrease leakage current. Meanwhile, the increase of oxygen on surface caused by passivation can largely decrease leakage current. When passivating time is 40 min, the wafers surface appears smooth and compact, which will decrease the density of surface state, the optimal electrical property of the wafer is therefore obtained.     

Effects of Interaction Between Surface Active Elements on the Surface Tension of Iron

Abstract

Surface tension data at 1650°C have been measured for the Fe + S + O ternary system and the two binary systems, Fe + O and Fe + S using the levitated drop technique. The results indicate that the reductions in surface tension due to oxygen and to sulphur are essentially additive in the ternary system. Excess concentrations (Γ) for both oxygen and sulphur have been calculated for both binary and ternary systems; an empirical rule for calculating Γ values for the ternary system from Γ values for the binaries has been proposed. The temperature dependencies (dγ/dT) for both ternary alloys and for a stainless steel were found to be positive. Surface analysis of the samples has been determined using electron spectroscopy (ESCA); the results indicated a considerable enhancement in the concentration of the surface active elements, O and S in the surface layers. The effects of additions of deoxidizers and desulphurizers like Al and Ce upon the surface tension have been investigated. The significance of the surface tension upon the welding characteristics of steels is discussed and the models for their interdependency evaluated in the light of the data obtained in this investigation.

Résumé

Les mesures de tensions superficielles ont été effectuées à 1650°C pour le système ternaire Fe-S-O et les systemes bin aires Fe-O et Fe-S au moyen de la technique de lévitation. Les résultats indiquent que les réductions de la tension superficielle sont essentiellement additifs dans le système ternaire. La concentration en excès (Γ) en oxygène et en sulfure a été calculée pour les systèmes bin aires et ternaires. Une règle empirique du calcul des valeurs de Γ pour le système ternaire a été établie à partir des valeurs des systèmes binaires. Les dépendances avec la température (dγ/dT) des alliages ternaires et de l'acier inox se sont révélées positives. L'analyse superficielle des échantillons a été éffectuée par spectroscopie électronique (ESCA). Les reésultats ont montré un enrichissement considérable dans la concentration des éléments actifs, O et S dans les couches superficielles. L'effet de désoxydation et désulfuration (Al et Ce) sur la tension superficielle a été étudié. L'effet de la tension superficielle des aciers sur la soudabilité est discuté et le modèle de leur interdépendance est évalué à la lumière des résultats de cette recherche.     

中间包内自由表面的实验研究

结合柳钢的生产实际，根据相似原理，通过相似比例为１：３的水模型实验，系统地研究了中间包水口流速，坝高，堰深及坝堰间距对中间包液面波动的影响，用浪高仪测定了不同情况下的自由表面形状，找出了影响中间包表面波动的敏感因素，实验结果对生产实际具有指导意义。     

Surface oxide on fcc iron-nickel alloys

Metallurgical and Materials Transactions A -