Dynamic Multicast Session Provisioning in WDM Optical Networks with Sparse Splitting Capability

In this work, we study dynamic provisioning of multicast sessions in a wavelength-routed sparse splitting capable WDM network with an arbitrary mesh topology where the network consists of nodes with full, partial, or no wavelength conversion capabilities and a node can be a tap-and-continue (TaC) node or a splitting and delivery (SaD) node. The objectives are to minimize the network resources in terms of wavelength-links used by each session and to reduce the multicast session blocking probability. The problem is to route the multicast session from each source to the members of every multicast session, and to assign an appropriate wavelength to each link used by the session. We propose an efficient online algorithm for dynamic multicast session provisioning. To evaluate the proposed algorithm, we apply the integer linear programming (ILP) optimization tool on a per multicast session basis to solve off-line the optimal routing and wavelength assignment given a multicast session and the current network topology as well as its residual network resource information. We formulate the per session multicast routing and wavelength assignment problem as an ILP. With this ILP formulation, the multicast session blocking probability or success probability can then be estimated based on solving a series of ILPs off-line. We have evaluated the effectiveness of the proposed online algorithm via simulation in terms of session blocking probability and network resources used by a session. Simulation results indicate that our proposed computationally efficient online algorithm performs well even when a fraction of the nodes are SaD nodes.     

氧气顶吹转炉溅渣护炉试验研究

采用水力模型研究方法 ,针对马钢 2 0t转炉进行溅渣护炉冷态模拟试验 ,得出最佳工艺参数为 :枪位 1680mm ,氮气流量为 110 0 0m3/h ,大流渣量 ,渣粘度适中。此外 ,在满足炼钢生产的条件下 ,采用夹角为 13°的喷头溅渣效果好     

ETR Ⅱ-30调速器液压控制系统

ETRⅠ-30调速器是瑞士爱舍维斯工厂生产的具有PID调节规律的电液调速器。本文对其液压控制系统作了较详细的介绍,供有关人员参考。     

用保形样条方法求解非定常对流扩散方程

在欧拉-拉格朗日分裂方法的基础上,本文发展了一种固定网格上的欧拉-拉格朗日分裂方法.保形样条方法(SPSM)被用来解决倒特征线插值问题.通过求解几个有精确解的例子,说明SPSM方法的解是单调无振荡的,并且数值耗散也是比较小的.     

AHMED experiments on hygroscopic and inert aerosol behaviour in LWR containment conditions: experimental results

Hygroscopic NaOH, CsI, CsOH and inert Ag aerosol behaviour at different temperatures and relative humidities (RH) has been studied in a well instrumented and controlled vessel of 1.81 m³ total free volume. Homogeneous thermal-hydraulic conditions for aerosol measurement in the vessel were achieved. The aerosol number and mass concentration were measured continuously during the experiments using a Condensation Nucleus Counter and a Tapered Element Oscillating Microbalance. The particle size distribution and chemical composition in the test conditions were measured by Berner low pressure impactors. In the case of NaOH the half life of the aerosol mass concentration was more than four times longer at low RH (22%) as compared to high RH (96%). The half lives of the CsOH and CsI aerosols were only twice as long at low RH as compared to high RH. Thus at high RH (96–97%) the half lives of CsOH and CsI were twice as long as the half life for the NaOH aerosol. The faster decay of the NaOH aerosol is due to the smaller density decrease of NaOH during water condensation. CsOH particles grew rapidly to their equilibrium size at all humidities. The measured equilibrium size for CsOH aerosol agree well with the calculated particle size at different RHs. Experimental results were also compared with calculations obtained by severe accident computer codes. These calculated results will be presented in a later paper.     

水力喷砂割缝增产增注技术的作用原理及展望

本文对从俄罗斯引进的水力喷砂割缝技术的发展过程、工作原理及该技术在大庆油田的试验情况做了详细的阐述。并对它的改进及其将来的推广与发展前景做了展望。     

6m焦炉移动设备故障分析及处理

对6m焦炉移动设备运行特点及损坏原因进行了分析，并对6m焦炉移动设备PLC系统，液压系统的故障及其处理方法进行了探讨。     

液压转向助力系统能耗特性的分析和比较

 为了提高汽车转向系统的工作效率，利用在典型路面条件下获得的实验统计数据，分析了中位开式和中位闭式两种液压转向助力系统的能量消耗． 经过对4种不同工作原理的转向系统的经济性和环境适应性的评价，指出电动中位闭式系统在节能方面具有明显的优势，但在工程应用中仍有不少技术问题需要进一步解决．     

落脚河水电站引水发电系统的调节保证计算分析

水轮发电机组在运行中遇到启动、正常停机、增减负荷、事故甩负荷等工况变化时，经常会引起引水发电系统的水力过渡过程，所以在设计中必须通过调节保证计算以选择合适的导叶调节规律及其调节时间，从而优化压力引水系统的运行工况，使水电站的水工建筑物布置既经济合理又安全可靠。     

河道溃堤与溃堤波的一、二维耦合计算数值模拟

建立了一维河道溃堤与二维溃堤波耦合计算的水力模型、其中，河道的计算采用一维明渠非恒定流Saint—Venant方程组，求解的过程与溃口的数值模拟耦合；溃堤按渐溃计算，将溃口模拟为梯形，随时间线性增大；溃堤波的计算采用在有限体积无结构网格上建立的TVD—MUSCL格式．模拟算例表明，建立的河道溃堤与溃堤波的一、二维耦合计算水力模型模拟结果比较接近真实溃堤过程．