用销钉式冷喂料挤出机作钢丝压延机供胶系统

本文论述了采用销钉式冷喂料挤出机作钢丝压延供胶系统的多种优点，并对销钉式冷喂料挤出机与开炼机的对比数据进行了分析。指出我国轮胎行业必须努力开发具有自主知识产权的新技术、新工艺设备和高新技术产品，此新型供胶系统是全钢载重子午线轮胎生产设备发展的方向。     

感应电动机的一种全局稳定控制方法

本文提出了使感应电动机系统为全局渐近稳定的状态反馈方法。按照本文的主要定理，可以对感应电动机系统构造多种状态反馈，所得闭环系统均是全局渐近稳定的。     

Influence of the mass flow rate of secondary air on the gas/particle flow characteristics in the near-burner region of a double swirl flow burner

The influence of the mass flow rate of secondary air on the gas/particle flow characteristics of a double swirl flow burner, in the near-burner region, was measured by a three-component particle-dynamics anemometer, in conjunction with a gas/particle two-phase test facility. Velocities, particle volume flux profiles, and normalized particle number concentrations were obtained. The relationship between the gas/particle flows and the combustion characteristics of the burners was discussed. For different mass flow rates of secondary air, annular recirculation zones formed only in the region of r/d=0.3–0.6 at x/d=0.1–0.3. With an increasing mass flow rate of secondary air, the peaks of the root mean square (RMS) axial fluctuating velocities, radial mean velocities, RMS radial fluctuating velocities, and tangential velocities all increased, while the recirculation increased slightly. There was a low particle volume flux in the central zone of the burner. At x/d=0.1–0.7, the profiles of particle volume flux had two peaks in the secondary air flow zone near the wall. With an increasing mass flow rate of secondary air, the peak of particle volume flux in the secondary air flow zone decreased, but the peak of particle volume flux near the wall increased. In section x/d=0.1–0.5, the particle diameter in the central zone of the burner was always less than the particle diameter at other locations.     

海藻酸钠的流变性及其纤维性能研究

选用黏均分子量分别为1.59×105和3.27×105的海藻酸钠(A)和海藻酸钠(B),用旋转黏度计研究了两种海藻酸钠溶液的流变性,用热重分析(TGA)、扫描电子显微镜(SEM)研究了海藻纤维的热性能及形态结构。结果表明:海藻酸钠溶液的流变行为具有一般非牛顿流体的基本特征;随剪切速率的增加,溶液黏度下降;温度升高,溶液黏度下降,溶液的非牛顿指数、黏流活化能、结构黏度指数(η)都发生变化;海藻酸钠B的η比海藻酸钠A的较低,可纺性较好;海藻纤维具有良好的热稳定性,其表面具有沟槽结构,较好的吸湿性。     

Preparation of Organic/Inorganic Composite Phenolic Resin and Application in Al2O3‐C Refractories

An organic/inorganic composite phenolic resin (CPR) was synthesized via silicon particles in situ composite with water‐soluble lignin–phenolic resin. It was observed that silicon particles were uniformly dispersed in the organic matrix. The oxidation activation energies of the pyrolytic products from CPR and commercial phenol formaldehyde resin (PF) were calculated as 173.3 kJ/mol and 102.4 kJ/mol, respectively, by nonisothermal kinetics method. Dumbbell‐shaped silicon carbide nanowires were formed on the surface of the pyrolytic carbon from CPR at high temperature. The oxidation resistance and mechanical properties of the Al₂O₃‐C refractories bonded with CPR were improved.     

The 600?°C and 700?°C Isothermal Sections of the Zn-Fe-Bi Ternary System

The 600 and 700?°C isothermal sections of the Zn-Fe-Bi phase diagram were determined by scanning electron microscopy coupled with energy dispersive x-ray spectroscopy and x-ray powder diffraction. Two three-phase regions have been confirmed in the 600?°C isothermal section, and one three-phase region has been identified in the 700?°C isothermal section. Bi is almost insoluble in the Fe-Zn binary compounds and ??-Fe, and the solubility of Fe in the L phase is limited.     

The Zn-Rich Corner of the Zn-Al-Fe-V Quaternary System at 450?°C

The 450?°C isothermal section of the Zn-Al-Fe-V quaternary system with Zn fixed at 93?at.% has been studied experimentally using x-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy. Zn-Al-Fe and Zn-Fe-V ternary phases T(Al) and T(V) have been found in this section. The maximum solubility of V in T(Al) is 4.7?at.% and that of Al in T(V) is limited. The addition of V can increase the solubility of Al in T(Al). The maximum solubility of Al in T(Al) is 8.4?at.%. Six four-phase regions have been confirmed experimentally. The liquid domain in the Zn-rich corner of the quaternary system at 450?°C is schematically constructed. No true quaternary compound is found in the present work.     

Effect of vanadium on galvanizing Si-containing steels

In the present study, the effect of V additions to the galvanizing bath on the microstructure and growth kinetics of the galvanized coating on Si-containing steels was experimentally investigated. Three different steels with effective Si contents of 0.158, 0.242 and 0.363 wt.%, were immersed for 0.5 to 8 min in Zn baths with four levels of V, ranging from 0 to 0.16 wt.%. The results indicated that V additions could adequately suppress the Si reactivity of all three steels. The potency of V increased with its increasing content in the bath. Crystallites of a ternary compound were found at the ζ/liquid interface.Based on the isotherms of Zn-Fe-V and Zn-Fe-Si-V systems at 450 °C, a diffusion path model was proposed to interpret the effect of V on galvanizing pure Fe or Si-containing steels. V in the bath introduced a new equilibrium state between the liquid and a ternary phase T and made the equilibrium state between the liquid-ζ phases metastable. Furthermore, the greater solubility of Si in T made the diffusion path more difficult to enter the (ζ + T + Liq. + FeSi) region and, thus, protected the integrity of a normal coating.     

A New Equation for Temperature Dependent Solute Impurity Diffusivity in Liquid Metals

An equation to predict the temperature dependence of solute impurity diffusivity in liquid metals has been derived by combining the Sutherland-Einstein formula with Kaptay’s unified equation on the dynamic viscosity of liquid metals. It has been demonstrated that consideration of the temperature dependence of the atomic radius of the diffusing species results in better agreement of the predicted diffusivities with the experimental data compared to when the temperature independent Goldschmidt atomic radius is used. Due to the simple-parameter nature of the equation, it could be very useful in predicting the solute impurity diffusivity in liquid metal when experimental data are scarce.