奥氏体化温度及冷却方式对20Mn2SiVB钢组织及性能的影响

通过各种试验手段,研究了20Mn2SiVB钢不同奥氏体化温度及不同冷却方式处理后其显微组织及其强度和塑性的变化,确定了最佳的热处理工艺。结果表明:900℃奥氏体化后风冷时钢的强塑性最好;在强塑性最佳时的微观组织是铁素体+粒状贝氏体。     

扩散阻挡层对Cu-Zr纳米合金膜电阻率与残余应力的影响

用磁控溅射和离子束溅射共沉积的方法分别在以单晶硅为基体的TiN,TaN,ZrN扩散阻挡层上沉积了Cu-Zr合金膜,膜在400℃氮气中退火1h.结果表明扩散阻挡层对膜的晶体取向、电阻率和残余应力有很大影响.沉积态的膜具有强的（111）取向,且峰型严重展宽;退火后峰型明显锐化,出现（200）等晶体取向;对应TiN,TaN;ZrN三种扩散阻挡层,膜的电阻率在沉积态时分别达108,327和478μΩ·cm,退火后降至正常的数个μΩ·cm;扩散阻挡层亦可明显降低膜的残余应力,无扩散阻挡层时膜的退火应力达475MPa,有ZrN扩散阻挡层后退火应力降至149MPa.     

碳对马氏体钢显微组织和力学性能的影响

通过固定其它元素的含量，调整碳含量的方式，研究了碳含量对马氏体钢显微组织和力学性能的影响。结果表明，随碳含量增加，马氏体钢的硬度和抗拉强度提高，但冲击韧度下降。     

碳对马氏体钢显微组织和力学性能的影响

通过固定其它元素的含量,调整碳含量的方式,研究了碳含量对马氏体钢显微组织和力学性能的影响。结果表明,随碳含量增加,马氏体钢的硬度和抗拉强度提高,但冲击韧度下降。     

钢筋混凝土阴极保护用高性能涂层钛阳极

通过对传统钛阳极涂液的改性以及烧结工艺的改进,制备出Ru-Ti-Ir新涂层阳极。X射线衍射及扫描电镜分析表明,涂层氧化物晶粒细小、均匀、达到纳米级,涂层表面无龟裂纹。电化学测试分析表明,电极的电催化活性及强化寿命明显优于传统阳极,此电极在钢筋混凝土外加电流阴极保护中具有很好的使用效果。     

On the applicability of diploid genetic algorithms in dynamic environments

Diploid genetic algorithms (DGAs) promise robustness as against simple genetic algorithms which only work towards optimization. Moreover, these algorithms outperform others in dynamic environments. The work examines the theoretical aspect of the concept by examining the existing literature. The present work takes the example of dynamic TSP to compare greedy approach, genetic algorithms and DGAs. The work also implements a greedy genetic approach for the problem. In the experiments carried out, the three variants of dominance were implemented and 115 runs proved the point that none of them outperforms the other.     

上海市不同历时暴雨组合概率研究

基于上海市徐家汇站1960—2011年的日降雨资料,分析上海市年最大1d和3d降水量年际变化和年代际变化特性;择优选择GH Copula函数构建了年最大1 d与3 d降水量的联合分布模型,并推算它们的同现重现期和组合风险概率。结果表明:年最大1 d和3 d降水随时间呈增加趋势,自20世纪70年代开始其均值随年代增加;年最大1 d和3 d设计暴雨同频遭遇风险率在75%~85%之间,且同现风险率随年最大1 d设计暴雨值增大而增加。在设计上海市防洪排涝标准时若考虑最大1 d和3 d降水量的遭遇组合,有利于提升防洪排涝能力,保障防洪安全。     

Design of Barrages with Genetic Algorithm Based Embedded Simulation Optimization Approach

Barrages are hydraulic structures constructed across rivers to divert flow into irrigation canals or power generation channels. The most of these structures are founded on permeable foundation. The optimum cost of these structures is nonlinear function of factors that cause the seepage forces under the structure. There is, however, no procedure to ascertain the basic barrage parameters such as depth of sheet piles or cutoffs and the length and thickness of floor in a cost–effective manner. In this paper, a nonlinear optimization formulation (NLOF), which consists of an objective function of minimizing total cost, is solved using genetic algorithm (GA). The mathematical model that represents the subsurface flow is embedded in the NLOF. The applicability of the approach has been illustrated with a typical example of barrage profile. The results obtained in this study shows drastic cost savings when the proposed NLOF is solved using GA than that of using classical optimization technique and conventional method. A parametric analysis has also been performed to study the effect of varying soil and hydrological conditions on design parameters and on over all cost.     

轴流转桨机组水力过渡过程中的轴向水推力研究

轴流转桨式机组水力过渡过程中出现的抬机现象会直接危及电站的安全稳定运行。本文通过对轴流转桨式水轮机轮叶的受力分析,根据瞬态旋转水力矩推导出轴向水推力计算模型,并将计算模型应用于草街水电站的过渡过程计算中,研究了防抬机的工程措施。     

基于远动系统实现电网地调水调自动化系统的数据通信

针对电网地调水调自动化系统建成过程中小水电厂通道条件差、难以实现水调数据到地调中心站传输这一难题,提出了复用远动系统通道方案,通过数据采集与监控(SCADA)系统远动通道实现水调数据传输,并在浙江丽水水库群调度支持系统中得到实际应用.