柔性轧制Q390C和Q420C钢板生产实践

目前市场对中厚板的订单具有个性化和多样化的特点，而对于不同强度级别的钢板，化学成分设计往往是不同的，这样会增加不同钢坯冶炼之间衔接的时间及化学成分控制的难度，导致冶炼成本增加，工序复杂化。结合市场需求与生产实际，采用同一Q390低合金高强度钢板坯，通过不同的控轧控冷工艺，对Q390C和Q420C两种强度级别热轧钢板进行了试制。结果表明，通过控轧控冷技术，可以充分发挥细晶强化作用，采用同一Q390低合金高强度钢板坯实现了Q390C和Q420C两个强度级别热轧钢板的柔性生产。试制生产的两种钢板，强塑性及0 ℃冲击功均满足标准要求，Q420C钢板屈服强度达441 MPa以上，抗拉强度达579 MPa以上。采用柔性轧制技术，降低了Q420C高强钢板的生产成本。     

Influence of Rare-earth Elements on Mechanical Properties of Palladium

The influence of 0.1-0.6 at.-%RE additions (RE= La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb) on themechanical properties of Pd was studied. All above RE additions increased not only the strengthproperties at ambient temperature but also the tensile strength, creep rupture time and activation en-ergy at high temperatures, simultaneously increased the elongation of Pd. In the range of dilute con-centration, the strength properties of Pd-RE alloy enhanced linearly with RE concentration. Whenthe strength properties of Pd-RE alloys were normalized at 0.1 at.-%RE, it was found that light REelements had stronger effect on the properties of Pd than heavy RE, whereas Eu, Yb, Ce had anoma-lous effect. In all Pd-RF alloys, Pd-Eu alloy had the highest strength properties, successively Pd-Yband Pd-Ce alloy. The effect mechanisms of RE in alloy, such as purifying impurities, increasingrecrystallization temperature, refining grain size. expanding crystal lattice, increasing dislocation den-sity and decreasing stacking fault energy, forming stable RE oxidation by internal oxidation, and soon, were observed. They were strengthening sensitive factors. The influence of the factors onstrength properties and elongation of Pd was discussed.     

Study on Numerical Simulation of Mold Filling and Solidification Processes under Pressure Conditions

The mold filling and solidification simulation for the high pressure die casting (HPDC) and low pressure die casting (LPDC) processes were studied.A mathematical model considering the turbulent flow and heat transfer phenomenon during the HPDC process has been established and paralled computation technique was used for the mold filling simulation of the process.The laminar flow characteristics of the LPDC process were studied and a simplified model for the mold filling process of wheel castings has been developed.For the solidification simulation under pressure conditions,the cyclic characteristics and the complicated boundary conditions were considered and techniques to improve the computational efficiency are discussed.A new criterion for predicting shrinkage porosity of Al alloy under low pressure condition has been developed in the solidification simulation process.     

钛合金表面激光熔凝一步制备复合生物陶瓷涂层

在经过渡层预处理的ＴＣ４钛合金表面上预置设定配比的ＣａＨＰＯ４·２Ｈ２Ｏ、ＣａＣＯ３混合粉末，比较少量Ｙ２Ｏ３粉末对合成与涂覆生物陶瓷涂层的影响。经优化激光工艺处理后，成功地实现了一步激光束合成与涂覆生物陶瓷涂层。该涂层具有优良的力学性能，且改善了值入材料弹性模量与生物硬组织的匹配性。Ｙ２Ｏ３对生物陶瓷涂层的合成及性能改善均有重要作用。     

iViewer:利用数据服务即时生成跨域数据视图

越来越多的企业和组织选择通过广域、开放的互联网作为其协作平台,业务决策者往往需要即时汇聚并综合分析来自多个部门的资源信息以进行临机决策。如何即时构建满足用户需求的跨组织数据视图,动态维护视图和数据源之间的一致性是需要求解的一个关键问题。提出了一种互联网环境下跨组织业务数据视图的动态生成方法iViewer,利用数据服务来封装自治、异构和动态变化的数据源;通过可视化和易用的数据服务组合操作来动态构建数据视图;提出了一种基于轮询的视图动态更新算法,维护数据源和数据视图的一致性,从而使得数据视图能够随数据源的变化而自主变化;详述了iViewer方法的原理和过程,并通过一个火灾应急处置场景中,面向指挥中心的跨部门火灾救援设备数据视图的动态生成过程例证了iViewer方法的效果。     

A new DSmT combination rule in open frame of discernment and its application

A new combination rule based on Dezert-Smarandache theory (DSmT) is proposed to deal with the conflict evidence resulting from the non-exhaustivity of the discernment frame. A two-dimensional measure factor in Dempster-Shafer theory (DST) is extended to DSmT to judge the conflict degree between evidence. The original DSmT combination rule or new DSmT combination rule can be selected for fusion according to this degree. Finally, some examples in simultaneous fault diagnosis of motor rotor are given to illustrate the effectiveness of the proposed combination rule.     

基于Simulink的永磁同步电机矢量控制系统研究

根据永磁同步电机(PMSM)在d-q坐标系下的数学模型,在Matlab/Simulink环境下,构建了永磁同步电机磁场定向矢量控制的仿真模型,并对PMSM控制系统进行了仿真研究,同时用仿真结果表明了该仿真模型的有效性以及控制算法的正确性,为永磁同步电机控制系统设计和调试提供了理论基础。     

基于局部积分均值的经验模态分解改进算法

端点效应和模态混叠现象是经验模态分解算法应用中存在的主要问题。在介绍标准经验模态分解算法的基础上,阐述了基于局部积分均值经验模态分解算法的基本原理,提出自适应的端点局部积分均值拟合线的拟合方法。改进算法通过距离相关度函数在待分解信号内部寻找与端点处信号变化趋势相关度最高的一段波形,并用此段波形的局部积分均值拟合线来重新刻画端点处的局部积分均值拟合线,将修正后的局部积分均值拟合线应用于EMD算法筛选过程中。仿真实验结果表明,改进算法有效抑制了模态混叠和端点效应现象,提高了分解的精度和可靠性。     

Kaman协议的形式化验证

Kaman协议是移动Ad Hoc网络安全认证机制,然而,协议设计者未对该协议的安全性作严格的形式化分析。协议复合逻辑PCL是验证协议安全属性的形式化方法,PCL逻辑能够简化协议安全分析过程。本文在协议复合逻辑PCL中描述Kaman协议并分析Kaman协议的安全属性,证明Kaman协议能够实现其安全目标。