Simulation of dynamic recrystallization in 23Co13Ni11Cr3Mo steel using a modified cellular automaton简

A modified cellular automaton（CA） program was developed to simulate the process of dynamic recrystallization（DRX） for 23Co13Ni11Cr3Mo ultrahigh strength steel.In this model,influences of deformation parameters on hardening rate and solute drag effect were considered.Moreover,an inverse analysis method was proposed for parameters identification of dislocation model and solute drag effect based on the results of isothermal compression tests on Gleeble-1500.Then,simulated microstructures under different deformation conditions were compared with those of experiments.A good agreement is achieved.Furthermore,influences of deformation parameters on microstructure evolution for 23Co13Ni11Cr3Mo steel were investigated in details.High strain is an effective measure to refine grain and improve homogeneity.Meanwhile,the desired deformation parameters are temperature of 1000-1050 °C and strain rate of 0.008-0.01 s-1 for obtaining grains smaller than 22.5 μm.     

软件定义网络的异构无线网络资源分配框架

针对各种智能设备在移动蜂窝网络中的普及及移动流量需求日益增长的问题,研究控制无线电带宽并将其分配给多个无线电用户设备,提出了一个基于软件定义网络（SDN）的资源分配框架,以及LTE/WLAN多无线电网络中异构资源分配算法。该框架将SDN范式应用到LTE-WLAN集成网络的异构资源分配,并进行了扩展,以整体的方式分配LTE/WLAN多无线电网络中的异构射频带宽。通过将集中式解决方案的功能分解到指定的网络实体的方式,来处理异构资源。模拟实验表明,所提框架可以较好地平衡网络吞吐量和用户公平性,且算法收敛性较好。     

求解0/1背包问题的自适应元胞粒子群算法

对0/1背包问题进行研究,提出一种自适应元胞粒子群算法。在算法设计过程中,重新定义粒子位置和速度的更新方程,引入自适应因子,为有效粒子的主动进化和无效粒子的主动退化提供依据,新的编码方式使得新产生的粒子能够以更大的概率和更快的速度成为有效粒子,将元胞及其邻居引入到算法中保持种群的多样性,利用元胞的演化规则进行局部优化,避免算法陷入局部极值。对多组不同规模的背包问题进行仿真实验,结果表明,该算法不仅可以有效求解0/1背包问题,而且能够以较快的速度搜索到精度较高的次优解甚至全局最优解,具有较好的稳定性。     

元胞自动机与软计算的集成及其应用

介绍了元胞自动机的思想来源和基本原理，对元胞自动机与敦计算的人工智能技术进行比较并加以集成，讨论了近年来它在混沌分形、图像处理、智能材料、机器学习、模拟复杂现象等领域中的应用成果，并对进一步研究进行展望。     

新型细胞微生理计的软件设计与实现

传统的微生理计是用于监测活细胞的功能性变化,检测参数单一,不能全面反映细胞的形态功能变化。我们实验室研发的新型细胞微生理计结合了多参数检测的细胞传感器集成芯片和自动分析控制仪器,可以多通道监测细胞代谢和形态变化,介绍针对该仪器的软件系统的设计和实现,并比较常用的自动检测LAPS工作点的算法后提出简单高效的工作点检测方法,研究了细胞酸化率和药物半数抑制浓度的计算方法。该软件系统可提供三种测量模式供用户检测细胞代谢,实时显示细胞各项参数值,可实时采集、记录、保存数据,自动控制流路通断,在线分析并实时向用户反馈细胞代谢和细胞形态变化。最后采用本软件系统进行了肾细胞酸化率测试实验和活化的肝星状细胞药物作用实验,通过对结果的分析讨论,验证了上述软件系统和算法的有效性。     

Channel capacity per user in a power and rate adaptive hybrid DS/FFH‐CDMA cellular system over Rayleigh fading channels

The theoretically achievable average channel capacity (in the Shannon sense) per user of a hybrid cellular direct sequence/fast frequency hopping code‐division multiple‐access (DS/FFH‐CDMA) system, operating in a Rayleigh fading environment, was examined. The analysis covers the downlink transmission and leads to the derivation of a novel expression between the average channel capacity available to each system's user under simultaneous optimal power and rate adaptation and the system's parameters, providing an optimistic upper bound, useful for practical modulation and coding schemes. The final derived closed‐form expression can be useful for the design of the DS/FFH‐CDMA system because it provides a theoretical tool for the initial quantitative analysis. Finally, avoiding the application of complex theoretical algorithm or lengthy simulation, we theoretically derived numerical results to illustrate the presented analysis. Copyright © 2011 John Wiley & Sons, Ltd.     

The effect of physical configuration on the performance of laboratory-scale oxidation ponds

This study describes an investigation into the effect of configuration and scale on the performance of oxidation pond systems. Laboratory studies with a synthetic milk wastewater used large and small series systems, and a large single pond. The performance of these systems was investigated using organic loadings in the range of 50–300 kg BOD₅/ha/d and detention times which ranged from 3.25 to 13 days at a temperature of 20°C. The differences between the performance of the three pond systems were analysed and it was shown that there was no significant difference between a series of four ponds and a large pond of equal total area and volume, and also between different scales of pond. The mathematical relationships developed suggest that the performance of the laboratory-scale system was comparable to that of a full-scale system.     

A novel tracer technique for the assessment of fine sediment dynamics in urban water management systems

Urban storm water run off can reduce the quality of receiving waters due to high sediment load and associated sediment-bound contaminants. Consequently, urban water management systems, such as detention ponds, that both modify water quantity through storage and improve water quality through sediment retention are frequently-used best management practices. To manage such systems effectively and to improve their efficiency, there is a need to understand the dynamics (transport and settling) of sediment, and in particular the fine sediment fraction (<63 μm) and its associated contaminants within urban storm water management systems. This can be difficult to achieve, as modelling the transport behaviour of fine-grained and cohesive sediment is problematic and field-based measurements can be costly, time-consuming and unrepresentative.The aim of this study was to test the application of a novel cohesive sediment tracer and to determine fine sediment transport dynamics within a storm water detention pond. The cohesive sediment tracer used was a holmium labelled montmorillonite clay which flocculated and had similar size and settling velocity to the natural pond sediment it was intended to mimic. The tracer demonstrated that fine sediment was deposited across the entire pond, with the presence of reed beds and water depth being important factors for maximising sediment retention. The results of the sediment tracer experiment were in good agreement with those of a mathematical sediment transport model. Here, the deposited sediment tracer was sampled by collecting and analysing surface pond sediments for holmium. However, analysis and sampling of the three dimensional suspended tracer ‘cloud’ may provide more accurate information regarding internal pond sediment dynamics.     

尾矿库在线监测预警系统降雨量预警阈值研究与应用

尾矿库在线监测预警系统设计中,降雨量预警阈值设定是关系到尾矿库防洪安全的重要问题。目前常采用的降雨量阈值确定方法计算的阈值,漏报概率大、空报率高,不能满足实际需求。本研究在对比常用方法的基础上,提出了基于地区水文特征的降雨量预警阈值确定方法,该方法充分考虑了土壤湿度和地区产汇流特性,大大提高了预警准确率,为尾矿库在线监测预警系统降雨量预警阈值的设定提供参考。     

折流式BAF/稳定塘工艺处理小城镇污水的效果分析

以三峡库区某小城镇污水处理厂为例,介绍了折流曝气生物滤池/稳定塘工艺的设计特点和运行效果.当进水量为800 m<'3>/d,进水COD、NH<,4>><'+>-N、TN和TP值分别为(14～315)、(1.00～41.72)、(4.90～50.16)、(0.30～3.79)mg/L时,出水水质优于GB 18918-2002的一级B标准.该工艺对低浓度进水水质与水质的波动具有良好的适应性.季节和温度变化对系统去除COD和TP的影响不明显,但冬季的NH<,4><'+>-N和TN去除率明显偏低.稳定塘能进一步净化曝气生物滤池出水,起到了良好的水质保障作用.