AN INVESTIGATION ON THE EFFECT OF MANGANESE SPECIFICATION IN BASIC OPEN HEARTH PROCESS

本文结合生产研究了鞍钢碱性平爐冶炼重轨和无缝等碳素镇静钢的锰制度.研究结果指出:就上述鋼种而言,熔炼过程中的锰制度对钢中氧、硫含量以及轧制的成品質量並没有实际影响,换句话说,并没有必要规定熔池含锰量高於一定水平(>0.15—0.2%Mn).相反地,熔池含锰较高或在熔炼过程中加入锰铁均使降碳速度趋於缓慢,从而延长了熔炼时间.因此,只要高炉铁水中含硫量能够合乎规定,用低锰生铁作原料对炼钢並无害处.通过高爐生产数据分析,说明在鞍钢的操作条件下完全有可能生产含锰低而含硫合乎上述规定的铁水,应该认为用低锰生鉄冶炼重轨和无缝类型的优質鋼是切实可行的.     

Elastic Moduli and Refractive Indices of Aluminosilicate Glasses Containing Y2O3, La2O3, and TiO2

Glasses in the system Al₂O₃-Y₂O₃-SiO₂, containing TiO₂ and La₂O₃, were investigated. Glasses of high refractive index and elastic modulus were developed. The observed Young's and shear moduli of these glasses show good agreement with theoretical values. Agreement was also found between the observed and calculated values of refractive index when the Appen's empirical coefficients were used.     

PURIFICATION OF AMYLASE FROM TILAPIA BY MAGNETIC PARTICLE

Recent development in magnetic carrier technology involves the use of nonmagnetic substrates attached to superparamagnetic particles forming functionally modified magnetic support to isolate a particular enzyme in a controllable magnetic field. In this study, the superparamagnetic particles were modified by epichlorohydrin and other agents to cross-link with starch to form the purification support. This affinity support was able to bind the amylase and was used in the purification of amylase from Taiwan tilapia. After ammonium sulfate precipitation of amylase from Taiwan tilapia, the modified superparamagnetic particles were able to purify the crude amylase by 20.78-fold with recovery of activity of 75.6%. The molecular weight of the amylase was estimated to be 66.1 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both crude and purified amylase reached an optimum at a pH of 8.0 and temperature of 50C, and the enzyme was stable between 20 and 50C.

PRACTICAL APPLICATIONS

Because of the rapid development of high technology such as carrier supports for enzyme purification, the development, research and application of magnetic carriers are timely needed. The present study demonstrated that the affinity superparamagnetic particles could be used as a carrier support to absorb and purify the amylase and that technology of affinity purification can be widely used in protein purification. Compared with the traditional chromatography used in the purification of proteins, this novel affinity superparamagnetic particle technology is rapid, has low operation cost, requires simple facilities, and involves easy separation and recovery of the enzymes.     

建筑废弃物在建筑材料中的应用

指出建筑废弃物的循环使用是我国建筑业落实科学发展观,实施节能减排,走可持续发展之路的重要方面,结合我国国情和资源节约型、环境友好型社会建设的总体要求,阐述了主要建筑废弃物现状及综合利用现状,以促进资源节约。     

基于CMOS的开关电容DC-DC降压变换器

在标准CMOS工艺的基础上,分析了基本串并电容组合开关电容DC-DC降压变换器的工作原理和集成方法.采用两个单端开关电容变换器反相并联联结,降低了输出电压波纹.利用电路内部节点电压驱动MOS开关管,避免了每个开关管都必须单独驱动.用SPICE软件对电路进行了瞬态分析,给出了分析结果.     

AN INVESTIGATION ON STRATIFIED INCLUSIONS IN MILD STEEL PLATES

本文研究了鞍山钢铁公司生产的沸腾钢中板所含的夹层,发现它们可以按照钢锭的不同部位区分为三种类型。权据夹层的分析结果和生产统计资料,讨论了这三利夹层的生成原因并对它们的防止办法提出了建议。     

System Voltage Control Based on Potential Game Theory Considering PV Output Prediction Error

Recently, in Japan, large‐scale introduction of photovoltaics (PVs) has been under way. This development increases the likelihood of system voltage increase and fluctuations, which can be prevented by employing PV output prediction. In this study, we focus our attention on applying PV output prediction to system operation with the objective of system voltage control. In this paper, 30‐min ahead prediction is assumed according to prior research with prediction error consideration. System voltages of 30 min ahead are estimated and are controlled in advance by using transformer taps and static capacitors. In this paper, voltage control is proposed for coordinating control, which is based on one of the games in the game theory, potential game. The validity of the proposed method is confirmed by running simulations using a modified IEEE 30 bus system. By applying the proposed method, both the voltage deviations and control counts improved considerably compared to a conventional method.     

AN INVESTIGATION OF INTERNAL DEFECTS IN HIGH-CHROMIUM STAINLESS STEEL

在高铬不锈钢的生产中,影响质量最严重的是钢锭中的轴心裂纹和钢材中的髪纹。本文的研究结果指出,这两种缺陷属于同一来源,没有轴心裂纹的钢锭在锻成钢材后也没有髪纹。 钢锭中轴心裂纹是在凝固过程中形成的,因而冷凝条件对它有影响。利用耐火材料做锭模可以得到内部坚实的钢锭,减小锭模模壁厚度,增大钢锭圆锥度或降低浇铸温度等只能减轻而不能完全消除裂纹。 熔炼过程中的脱氧方法对钢中夹杂物的性质和形状分布有影响。改善脱氧方法并采用薄模浇铸,可以大大地减少轴心裂纹和髪纹,从而提高钢的收得率。我们认为夹杂物的性质、多寡及其形状分布可能对钢液的流动性和表面张力有影响;改善钢液的流动性或减小其表面张力可以促进钢液的充填性能,从而弥补凝固过程中由于冷凝收缩而产生的缺陷。 在一定压力以下的真空中熔化和浇铸可以得到内部良好的钢锭。通过真空熔铸所得到的钢锭,其柱状晶区大小缩小,而柱状晶的缩小对避免钢锭中轴心裂纹有利。得到这种效果的原因可能是多方面的,真空有去气作用,在真空中钢锭的凝固散热与在一般情况下有所不同,真空作用使钢液的性质发生变化等等。虽然,上述几方面的理论基础还有待于进一步研究,但从目前实际效果来说,真空熔化和浇铸应该认为是提高不     

Estimation and Kinetic Modeling of Human Arm using Wearable Robot Arm

This paper describes an estimation method for the physical parameters of human arms. The parameters are used in the medical and kinematic analysis fields. Personal differences are important, but some of the conventional methods do not consider personal differences pertaining to inertia in viscoelasticity muscular strength measurements. The remaining conventional methods that consider personal differences require precise measurement devices. The proposed method realizes kinetics modeling and identification of the friction and inertia including the off‐diagonal parameters of human arms by using wearable robots. First, wearable robots are multi‐input devices. In addition, the actuators of wearable robots can be located near human joints and can input M‐sequence torque. Therefore, wearable robots can input signals having a high signal‐to‐noise ratio and ensuring persistently exciting characteristics in each human joint. By employing multi‐input characteristics, the proposed method can reduce patients’ burden by shortening the amount of time for estimation. In addition, we verify the accuracy of the estimated parameters by comparing the responses of the actual machine with those obtained by simulation.