Evolution of textures and microstructures in IF-steel sheets during continuous confined strip shearing and subsequent recrystallization annealing

Interstitial free (IF) steel sheets were deformed by continuous confined strip shearing (CCSS) based on the equal channel angular pressing (ECAP). The samples were deformed by CCSS up to three passages and subsequently recrystallized at 700°C for 1 h. The strain history of IF steel sheets in the CCSS die-channel was tackled by finite element method (FEM) simulations. The deformation by CCSS led to the shear deformation and consequently the formation of shear texture components. With increasing number of CCSS passages, the intensity of the deformation texture was hardly increased. The recrystallization texture resembled the deformation texture. The orientation stability was discussed by mean of Taylor deformation model and the formation of recrystallization textures was discussed by occurrence of the discontinuous recrystallization. Observations by transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD) revealed the formation of ultra-fine grains in IF sheets deformed by CCSS.     

基于人工神经网络的中厚板控冷温度预测

基于BP神经网络建立轧后控制冷却主要参数和目标参量之间的关系并对模型进行训练 ,实现轧后控制冷却终冷温度和冷却速度的预测。利用现场实测数据仿真表明 ,模型有效提高了预测精度。     

凌钢高炉风口攻关实践

分析了风口破损的原因 ,并采取了缩小进风面积、提高标准风速 ,推广使用斜长风口 ,减少原燃料入炉粉末 ,活跃炉缸工作 ,提高冷却强度等措施 ,大大减少了风口破损数量。与 2 0 0 2年相比 ,风口 (小套 )破损率下降了 45 %以上。     

硫酸法生产钛白粉水洗工艺真空系统设计改造方案与思路

讨论了水洗真空度对水洗工艺的影响，提出水洗真空系统的改造原则，并对真空系统改造设计思路和方案进行了详细的探讨。通过改进和优化能够提高设备的使用率，最终达到缩短水洗时间，提高本工序产能的目的。     

氟化钡晶体质子辐照损伤分布的计算

根据经典辐射理论，描述质子辐照BaF2晶体的能量损失，讨论受照晶体的辐照损伤分布，用Monte Carlo方法模拟碰撞过程，具体用TRIM程序分别计算出能量为1．5Mev和2．0Mev质子辐照BaF2晶体所产生的辐照损伤，对计算结果进行讨论，将这两种能量情况下的BaF2晶体辐照损伤分布进行比较。得到的结论与实验结果基本相符。     

Effects of surface treatment of field emitter arrays on electrical characteristics of active matrix cathode

The effects of a wet chemical surface treatment of molybdenum-tip (Mo-tip) emitters on the electrical characteristics of an active matrix cathode composed of hydrogenated amorphous silicon thin film transistors and Mo-tip emitters are described. X-Ray photoelectron spectroscopy measurements showed that the surface treatment removed MoO₃ from the surface of the e-beam evaporated Mo film. In addition, the surface roughness of the Mo film was increased as the result of the surface treatment. The surface-treated active matrix cathode showed stable emission characteristics and immunity from emitter failures during its operation. The response time of the active matrix cathode was decreased by the surface treatment of the Mo-tip emitters. A change in surface composition and surface roughness appear to be responsible for the enhancement of the active matrix cathode.     

循环温度场下氢对TC4钛合金组织和性能的影响

由于TC4钛合金工件在冶炼、锻造、机械加工、热处理及周围环境中渗入一定数量的氢,含有氢的TC4工件在空间承受较大温差的循环作用,TC4工件的力学性能、组织状态及应力状态有可能发生变化,本文研究在空间温度场中氢含量对TC4工件的组织和力学性能的影响.     

Generalized Linear Quadratic Gaussian Techniques for the Wind Benchmark Problem

This paper presents a comprehensive study of the stage-3 benchmark problem for response control of wind-excited tall buildings based on the linear quadratic gaussian (LQG) approach, and on its generalization, the k-cost-cumulant control method. For control design, the original nodal building model is first transformed into balanced modal space. The Hankel singular values (HSVs) and the power spectral density of the wind disturbances are calculated; and, based on them, a reduced-order model is derived by keeping the first six low-frequency modes. A balanced LQG (BLQG) controller is then determined by adopting the HSVs as a basis to choose the design weights. The main results of the paper are that the BLQG control design is able to come within 5–10% of the performance of the sample LQG controller supplied with the benchmark, but with control actions on the order of one-third less than the sample LQG, and with stability improvement features of a substantial nature over the range of stiffness perturbations specified in the benchmark. Finally, if the low authority BLQG controller is regarded as a one-cost-cumulant design, then with the appropriate use of the second-cost cumulant, the latter methodology is able to demonstrate how higher-authority controllers can give certain improvements in performance, but at the expense of significant investment in control action.     

Estimation of break location and size for loss of coolant accidents using neural networks

In this work, a probabilistic neural network (PNN) that has been applied well to the classification problems is used in order to identify the break locations of loss of coolant accidents (LOCA) such as hot-leg, cold-leg and steam generator tubes. Also, a fuzzy neural network (FNN) is designed to estimate the break size. The inputs to PNN and FNN are time-integrated values obtained by integrating measurement signals during a short time interval after reactor scram. An automatic structure constructor for the fuzzy neural network automatically selects the input variables from the time-integrated values of many measured signals, and optimizes the number of rules and its related parameters. It is verified that the proposed algorithm identifies very well the break locations of LOCAs and also, estimate their break size accurately.     

声表面波谐振器无源无线传感虚拟仪器系统

分析了在通用硬件平台上结合软件设计的声表面波谐振器无源无线传感虚拟仪器系统。该系统通过设计虚拟仪器实现部分硬件功能,控制闭环系统实现自动检测,并采用数字信号处理方法提高检测系统的精度,从而避免了通常的复杂硬件系统,降低硬件成本,并使检测更灵活。本文介绍了设计原理和系统构成,并对系统的误差进行了分析。实验表明:该仪器系统能够达到5m的无线检测距离。