Abnormal growth of austenite grain of low-carbon steel

Niobium is an important alloying element for the steel. To know further the effect of Nb in the steel, the contrast experiments on the austenite grain growth of the 0.015%Nb and free Nb steels were carried out using Gleeble 1500 thermomechanical simulator. The experimental results indicate that the austenite grain of 0.015%Nb steel is finer than that of Nb free steel at 1150–1230 °C. And when the heating temperature arrives the critical temperature 1240 °C, the austenite grain of Nb steel suddenly grows up, while the austenite grain of Nb free steel changes little. Finally, the austenite grain of Nb steel is obviously coarser than that of Nb free steel. By transmission electron microscopy (TEM) using a carbon extraction replica technique, the precipitates of Nb(C,N) were not observed in the 0.015%Nb steel. It is concluded that the grain-boundary internal adsorption of Nb atoms leads to the result.     

Particularities of condensation of atoms with increased kinetic energy

Novel universal method for measurement of the condensation coefficient α is developed. Using this method, noticeable difference between measured (α≈0.8) and expected (α≈1) values of the condensation coefficient for sputtered Cr atoms was revealed for the first time. The effect is assumed to be a result of considerable elevation of the surface temperature during atomic condensation induced by the energy delivered to the condensation surface by sputtered atoms and from the plasma.     

High temperature piezoelectric materials: Defect chemistry and electro-mechanical properties

Langasite (La₃Ga₅SiO₁₄, LGS) and gallium orthophosphate (GaPO₄) resonators exhibit piezoelectrically exited bulk acoustic waves at temperatures of up to at least 1400^∘C and 900^∘C, respectively. Their mass sensitivity at elevated temperatures has been found to be about as high as that of quartz at room temperature. Within its operation temperature range, GaPO₄ shows significantly lower losses than LGS. Factors restricting application relevant properties of LGS at elevated temperatures, such as the mass resolution, include excessive viscous damping. Therefore, the effective viscosity is determined as a function of the temperature by fitting the calculated complex impedance to the experimental data in the vicinity of the resonance frequency. The viscosity shows an Arrhenius-like behavior if a temperature independent contribution is subtracted. The activation energies of the viscosity for LGS and GaPO₄ correspond to those of the bulk electrical conductivity for each material. Viscosity and conductivity are obviously correlated. Therefore, it is highly likely that the predominant conductivity mechanism also controls the mechanical damping. First attempts to minimize the viscosity of LGS by doping are undertaken. Very light doping does, however, not change the conductivity and viscosity of LGS. Higher doping levels have to be applied and tested. Based on the electromechanical properties given for undoped LGS, the applicability of this material as resonant gas sensor at 600^∘C is demonstrated.     

有限差分法计算HF分子的振动能级和光谱

本文用有限差分法计算了HF分子的振动能级并且把计算的结果用切比雪夫法进行拟合得到了HF的光谱项,将所得结果与黄整等人的用时域有限差分法计算所的结果和实验值进行了比较。     

多元回归分析在电热式平板硫化机热板温度场中的应用

分析电热平板硫化机热板温差大的主要影响因素,重点研究热源分布情况对温差的影响.以400×400电热平板硫化机为例,应用多元回归的二次响应曲面模型及其子模型,对热源间距(电热管间距)与热板表面最大温差之间的函数关系进行预测,检验并分析预测结果(拟合曲线)的可靠程度,从而得出较合理的数学模型,即完整二次响应曲面模型.此模型可为工程设计提供参考依据.     

活性污泥生物吸附性能的研究

探讨了活性污泥生物吸附作用的影响因素。吸附性能随温度升高而降低,在20~30min之间,可达到吸附平衡,且温度越高,达到吸附平衡的时间越长;活性污泥对悬浮性有机物的吸附性能高于对溶解性和胶体性有机物的吸附;对高浓度污水吸附性能高于低浓度污水的吸附性能;抑制剂对污泥的吸附作用有影响。     

从EOS/MODIS数据中提取夜间强对流云团的闪电信息

主要探索用EOS/MODIS极轨卫星监测闪电的可行性,应用大气和云辐射原理以及云中水滴mie散射的原理,从EOS/MODIS的中红外通道及热红外通道中提取夜间强对流云团产生的闪电信息,并可由强对流卫星云图的云顶温度确定可能出现冰雹的区域,对减灾、预警提供宏观信息。     

用于现场测试的温湿度采集系统软件

介绍了用于现场测试的温湿度采集系统软件新的特点、功能及其设计和使用.     

攀钢1450mm热连轧机层流冷却控制系统的开发及应用

阐述了攀钢1 450 mm热连轧机层流冷却控制新系统的开发与应用。该系统采用α机过程控制系统,通过预设定、在线前馈和自适应三大功能,对层流冷却模式、冷却速率和最终卷取温度进行控制,卷取温度控制精度较原系统有较大提高,±20℃的命中率由原来的88.6%提高到现在的96.4%。     

虚拟仪器在温度测控系统中的应用

虚拟仪器是由软件实现的，其软件开发平台是LabVIEW。以间歇式造气炉气化层的温度为例，用LabVIEW构建对造气炉气化层温度进行在线实时测量与控制的系统，从而可以降低操作人员的工作难度和强度，提高效率，达到对造气炉状态的实时控制。