Localization and quantification of radical production in cavitating flows with luminol chemiluminescent reactions

Hydrodynamic cavitation experiments in microfluidic systems have been performed with an aqueous solution of luminol as the working fluid. In order to identify where and how much reactive radical species are formed by the violent bubble collapse, the resulting chemiluminescent oxidation reaction of luminol was scrutinized downstream of a constriction in the microchannel. An original method was developed in order to map the intensity of chemiluminescence emitted from the micro-flow, allowing us to localize the region where radicals are produced. Time averaged void fraction measurements performed by laser induced fluorescence experiments were also used to determine the cavitation cloud position. The combination void fraction and chemiluminescence two-dimensional mapping demonstrated that the maximum chemiluminescent intensity area was found just downstream of the cavitation clouds. Furthermore, the radical yield can be obtained with our single photon counting technique. The maximum radical production rates of 1.2*10⁷ OH/s and radical production per processed liquid volume of 2.15*10¹⁰ HO/l were observed. The proposed technique allows for two-dimensional characterisation of radical production in the microfluidic flow and could be a quick, non-intrusive way to optimise hydrodynamic cavitation reactor design and operating parameters, leading to enhancements in wastewater treatments and other process intensifications.     

网格资源管理系统模型研究

网格资源管理系统是网格计算系统的重要组成部分。文章分析了网格资源管理系统的功能需求，具体论述了该模型的原型系统，最后介绍了相关研究工作。     

现代军用通信设备结构设计新理念

科学技术在不断发展，军用通信设备结构设计的内涵也在不断丰富，时代在不断进步，人们对设备的审美要求越来越高，设计人员应顺应时代发展的潮流，积极吸收、采用新的设计理念。本文详细讨论了有关军用通信设备结构设计新理念的主要内容-创新设计、模块化设计、小型化设计、工业设计和超前设计。     

基于多信道预约可冲突避免的多址接入协议

本文为多跳分布多无线网络提出了一套灵活而有效的自适应获取冲突避免（AACA）的多址接入协议。在该协议中，各节点竞争公共信道，利用RTS/CTS对话形式来预约各业务信道，成功预约后的分组传输不会受到其他节点的干扰。它使用任意确定数目信道，以异步方式工作，并且使得各节点利用半双工无线电台就可以灵活、简便地实现资源预约。分析和比较结果说明，所提出的多信道预约协议可以有效地解决隐藏终端、暴露终端以及侵入终端的问题。     

基于双阈值的视频平滑控制方法

在现有的TCP／IP网络中进行多媒体通信，服务质量是人们关注的重要内容。作为服务质量中的一项指标，视频平滑已成为研究和应用开发的一个热点问题。分析当前控制视频平滑的方式，提出一种基于双阈值视频平滑的控制方法。这种方法能够有效地改善视频平滑性能。     

Engset multi‐rate state‐dependent loss models with QoS guarantee

We consider a single link loss system of quasi‐random input, described by the Engset multirate loss model (EnMLM). Blocked calls may once reattempt to be connected to the system requiring less bandwidth; then the system is described by the single retry model for finite sources (f‐SRM). The EnMLM and the f‐SRM are extended with the single threshold finite source model (f‐STM), where calls may attempt to be connected to the system with less bandwidth requirements, according to the link occupancy, before blocking occurs. We focus on CBP equalization in the EnMLM, f‐SRM and f‐STM, under the bandwidth reservation (BR) policy. For this analysis, we apply two approximate methods, the Roberts' method and the method of reverse transition rates (RTR), which lead to a recursive CBP calculation. We evaluate the accuracy of the above models under the BR policy by comparing the analytical with simulation CBP results, based on the relative approximation errors (RAE). The results are highly satisfactory because they show that the proposed models (formulas) lead to small RAE. Copyright © 2005 John Wiley & Sons, Ltd.     

A capacity reservation game for suppliers with multiple blocks of capacity

This paper studies a supplier competition model in which a buyer reserves capacity from a number of suppliers that each have multiple blocks of capacity (e.g., production or power plants). The suppliers each submit a bid that specifies a reservation price and an execution price for every block, and the buyer determines what blocks to reserve. This game involves both external competition between suppliers and internal competition between blocks from each supplier. We characterize the properties of pure-strategy Nash equilibria for the game. Such equilibria may not always exist, and we provide the conditions under which they do.     

一种用于波长路由光网络的分布式快速波长预留协议

波长预留协议用于在光通道建立过程中预留和配置波长.目前已有的波长预留协议都把协议设计的目标定为降低网络阻塞率,没有一种协议设计把目标定为缩短光通道的建立时间和简化协议处理过程.然而更短的建立时间和更小的协议复杂度对于未来极其动态的光网络却是非常重要的.提出了一种新颖的用于波长路由光网络的分布式快速波长预留协议-目的端预留协议,它在保证网络阻塞率可以接受的前提下,不仅可以降低连接建立时间,还可以减少控制节点处理器需要处理的信令消息数量.仿真结果证明了这一点.     

Aeroelastic analysis of swept pre-twisted wings

In this paper, aeroelastic modeling of aircraft wings with variations in sweep angle, taper ratio, and variable pre-twist angle along the span is considered. The wing structure is modeled as a classical beam with torsion and bending flexibility. The governing equations are derived based on Hamilton’s principle. Moreover, Peters’ finite state aerodynamic model which is modified to take into account the effects of the wing finite-span, the wing sweep angle, and the wing pre-twist angle, is used to simulate the aerodynamic loads on the wing. The coupled partially differential equations are discretized to a set of ordinary differential equations using Galerkin’s approach. By solving these equations the aeroelastic instability conditions are derived. The results are compared with some experimental and analytical results of previous published papers and good agreement is attained. Effects of the wing sweep angle, taper ratio, bending to torsional rigidity, and pre-twist angle on the flutter boundary in several cases are studied. Results show that these geometrical and physical parameters have considerable effects on the wing flutter boundary.     

一种基于TDMA的Ad Hoc网络的虚电路建立协议

为了实现网络中端到端的可靠传输,在基于TDMA的Ad Hoc网络里引入一种虚电路建立协议.该协议采用分布式的资源预约方式建立虚电路,对于网络拓扑变化所引起的链路故障,能够及时发现和处理,且具有相对较小的开销和较高的可靠性,比较适合Ad Hoc网络.