宽带光纤传送网的分层恢复技术与层间综合自愈策略

宽带光纤传送网中各层的恢复技术都得到了研究和发展 ,各层的恢复技术具有各自的特点 ,为了有效地提高全网的生存性 ,必须以一种综合的方式将各层的恢复技术纳入到一个统一的自愈策略中去。文中在宽带光纤传送网分层模型的基础上 ,分别分析了 SDH层、ATM层和光层恢复技术的特点 ,并提出了一种将串行启动和并行启动有效结合的层间综合自愈策略。     

要闻集锦

要闻集锦·上海信息港工程全面启动，目标为：在继续发展现有电话网、移动通信网、有线电视网、数字数据网等基础上，建设和完善宽带高速光纤传输网、窄带综合业务数字网、异步传输模式、数字移动网等，使该市的信息传输平台的信息传送能力具有宽带、高速、大容量、多媒体...     

城域传送网及宽带接入网的管理与发展策略

在对目前我国通信行业主管部门对城域传送网和宽带接入网管理现状分析的基础上，分析了我国城域传送网和宽带接入网发展现状，讨论了山西移动城域传送网和宽带接入网的健康发展策略。     

SDH自愈环的优化

从SDH自愈环的时隙重复使用原理出发，阐述了C3 SDH传送网的优化思路，并结合网络中的设备和光纤资源情况给出了具体的解决方案。     

具有多优先级虚通道的ATM网络综合自愈策略

在构建以ＡＴＭ技术为核心的宽带综合业务数字网中，对网络的生存性提出了越来越高的要求。分析了ＡＴＭ网络中的各种自愈技术，提出了一种具有多优先级虚通道的综合自愈策略，并对其进行了计算机模拟验证。     

全球光传送网络及设备的发展与趋势

随着宽带多媒体业务的迅猛发展，全球光通信市场还将继续增长。通过介绍全球光传送网设备及市场现状，分析运营商光传送网建设及试验进展策略，进而预测光传送网未来的发展趋势。     

宽带提速环境下城域传送网组网策略及演进分析

在宽带资费下降及免费提速的双重影响下,上网用户数及用户带宽会急剧增长,对城域传送网造成较大的影响和冲击。在此环境下,文章对网元部署及城域传送网的网络结构进行分析,详细探讨了汇聚及接入层的组网策略,并提出演进方案。     

光交叉连接器的光传输中的应用

目前以IP业务为代表的数据业务爆炸式增长,单信道传送速率从2.5Gb/s到10Gb/s到40Gb/s的快速增长,密集波分复用技术的使用,骨干网的电信级大容量快速交换需求,使得对光传送网交换节点的要求越来越高.网络的生存性、网络的恢复和自愈问题都变得非常重要.光交叉连接器(OXC)技术的发展,替代了复杂昂贵的电交叉连接,使空闲光纤数减少.同时,不需要光电转换,提供了比电交叉连接更高的交换效率.OXC能在光层解决网络恢复和自愈问题,极大地提高了网络的生存性和恢复速度.因此,光交叉连接器作为光传送网的关键设备,它的发展将对光传送网起到重大的推动作用.     

中国光纤传送网的发展

本文首先介绍中国光纤传送网建设的现状与特点,从９０年代起中国光纤传送网进入大发展进期,这一发展速度随着电信业务的增长还将继续,但技术层次更高,ＤＷＤＭ技术的极用将使中国光纤传送网的建设进入新阶段。本文还介绍了中国光纤传输系统开发的情况,最后讨论了为适应宽带多媒体业务特别是ＩＰ业务的发展,ＳＤＨ,ＤＷＤＭ系统和光传送网的研究开发和设计需要考虑的一些问题．     

T-MPLS中双重自愈机制及信令扩展研究

作为下一代网络的重要部分,分组传送网当前的热点是源于MPLS技术的T-MPLS。分组传送网对生存性有着比TDM传送网更多的要求,这对T-MPLS是很大挑战。本文提出了一种基于FRR的双重自愈机制,并给出了相应的信令扩展,它能显著改善网络的自愈性能。     

基于反馈机制的自愈算法

提出了一种网络自愈算法,当网络中的节点发生故障或链路出现拥塞时,该算法利用Q学习的反馈机制、多QoS约束的评价函数和基于Boltzmann-Gibbs分布的路径选择策略,自适应地选择恢复路径,降低了选择发生故障和拥塞路径的概率,从而实现了自愈。仿真结果表明,该算法在恢复率、区分业务能力和网络资源优化等方面,表现出了良好的性能。     

Trajectory Controlling and Collision Warning Device Based on Self-Healing and Conductive Castor Oil-Based Waterborne Polyurethane in Automated Guided Vehicles

Sustainable castor oil-based waterborne polyurethanes (WPUs) are widely applied in multiple fields, while the strategies to simultaneously realize reprocessing, self-healing, and novel applications are attractive and highly demanded. Herein, a molecular design strategy is proposed to incorporate dynamic oxime-carbamate bonds into the castor oil-based WPUs. The obtained networks exhibit excellent toughness (>44 MPa), adequate stretchability, and wonderful self-healing efficiency (>95% at 80 °C for 8 h), which stand out among the reported cases. Moreover, the WPU film retained almost 100% of the original mechanical properties after consecutive reprocessing. With the incorporation of carbon nanotubes, the films are endowed with good electric conductivity, providing a general platform for fabricating flexible electronic devices. Specifically, wonderful performance in trajectory control and collision warning is displayed, which is expected to be an alternative to minimize the utilization of expensive and complex obstacle sensors in automated guided vehicles. This study contributes to the development of sustainable and self-healing WPU-based flexible material and opens the gate for novel and identified applications.     

Self-healing in wideband packet networks

A brief overview is given of wideband packet technology (WPT), with special attention to the features affecting the feasibility of self-healing, a method for automatic failure recovery proposed herein. The objectives of self-healing are set forth, and the failure detection strategy is described. With this strategy, nondisruptive trunk monitoring (self-monitoring) at the data link layer of an open system interconnection (OSI) reference model is performed to detect facility failure of under 1 s. The bit error rate (BER) on a transmission link is estimated on the basis of counts of the number of packets with cyclic redundancy check (CRC) errors at the data link layer. This failure detection strategy can respond to link failures for any given traffic mix by the provisioning of duration and level of unacceptable sustained BER. The mechanisms used to achieve recovery in frame-relay networks using packet streams to carry users' traffic are discussed. Provisioning of the WPT nodes and the network is addressed     

一种改进AODV重路由算法在无线Mesh网络中的应用

本文在AODV路由协议的基础上提出了一种基于无环替代(LFA)的前摄性重路由机制,旨在提高无线Mesh网络的快速自愈的能力.文中首先介绍了AODV的改进AODV备份路由协议,并指出AODV备份路由协议的不足,然后提出了基于无环替代的AODV路由算法AODV-LFA,最后通过NS仿真实验,比较了AODV、AODV备份路由和AODV-LFA的丢包率、端到端时延等,表明AODV-LFA具有更强的自愈能力.     

Exploration and Application of Self-Healing Strategies in Lithium Batteries

Lithium batteries (LBs) are developed tremendously owing to their excellent energy density as well as cyclic persistence, exhibiting promising applications from portable devices to e-transportation and grid fields. However, with the ever-increasing demand for intelligent wearable electronics, more requests are focused on high safety, good durability, and satisfied reliability of LBs. The self-healing route, which can simulate the ability of organic organisms to repair damage and recover initial function through its intrinsic vitality, is believed to be an efficient strategy to alleviate the unavoidable physical or chemical fatigue and damage issues of LBs, beneficial for the realization of the above mentioned high requests. In this review, the applicability and development of self-healing materials are summarized in electrodes, electrolytes, and interfacial layers in recent years, focusing on exploring the feasibility of different self-healing strategies in LBs, discussing the advantages and disadvantages of existing strategies in different parts of batteries, and indicating the possible research directions for beginners who are interested in this field. Finally, the critical challenges and the future research directions as well as opportunities are prospected.     

基于无环替代重路由的无线Mesh网络自愈策略研究

无线Mesh网络的链路不可靠特性容易造成网络的不稳定和转发不连续,前摄性重路由可以解决这一问题。该文对基于无环替代重路由的无线Mesh网络自愈策略进行研究,提出了基于无环替代的AODV路由AODV-LFA,仿真实验表明AODV-LFA比AODV具有更强的自愈性能。     

Self-Healing and Recyclable Polymer Electrolyte Enabled with Boronic Ester Transesterification for Stabilizing Ion Deposition

Damage to solid polymer electrolytes can lead to mechanical degradation, short circuits, or functional failures. Therefore, introducing a self-healing function to solid polymer electrolytes is an ideal strategy to improve the safety and reliability of electrolyte systems. Herein, dynamic boronic ester-based self-healing polymer electrolytes (DB-SHPEs) with excellent mechanical properties and interfacial stability are developed via a thermally initiated ring-opening reaction between thiol and epoxy groups. The DB-SHPEs containing boronic ester bonds can not only alter the topologies via boronic ester transesterification and exhibit good self-healing capability but also enable homogeneous deposition of Li ions on the Li metal through the Lewis acid–base interactions between boron atoms and salt anions. Furthermore, the boronic ester bonds can endow the DB-SHPE with reprocessability and recyclability taking advantage of associative transesterification reaction. More significantly, the Li/DB-SHPE/Li symmetric cells exhibit a stable voltage plateau after cycling for 1200 h and the LiFePO₄/DB-SHPE/Li batteries present excellent cycling performance, suggesting that high-performance self-healing polymer electrolytes with multiple functions are promising materials for the next-generation lithium metal batteries.     

Self-Healing,Robust, and Stretchable Electrode by Direct Printing on Dynamic Polyurea Surface at Slightly Elevated Temperature

Printed electronics on elastomer substrates have found wide applications in wearable devices and soft robotics. For everyday usage, additional requirements exist for the robustness of the printed flexible electrodes, such as the ability to resist scratching and damage. Therefore, highly robust electrodes with self-healing, and good mechanical strength and stretchability are highly required and challenging. In this paper, a cross-linking polyurea using polydimethylsiloxane as the soft segment and dynamic urea bonds is prepared and serves as a self-healing elastomer substrate for coating and printing of silver nanowires (AgNWs). Due to the dynamic exchangeable urea bond at 60 °C, the elastomer exhibits dynamic exchange of the cross-linking network while retaining the macroscopic shape. As a result, the AgNWs are partially embedded in the surface of the elastomer substrate when coated or printed at 60 °C, forming strong interfacial adhesion. As a result, the obtained stretchable electrode exhibits high mechanical strength and stretchability, the ability to resist scratching and sonication, and self-healing. This strategy can be applied to a variety of different conducting electrode materials including AgNWs, silver particles, and liquid metal, which provides a new way to prepare robust and self-healing printed electronics.     

Water-Insensitive Self-Healing Materials: From Network Structure Design to Advanced Soft Electronics

Polymeric materials capable of spontaneously healing physical damages and restoring various functions have been attracting growing interest. Among these, the category of water-insensitive self-healing materials emerges as a promising research focus due to their reliable self-healing and stable mechanical properties in high-humidity environments and even underwater. In this review, an update on the significant advancements in the design of water-insensitive self-healing polymers is presented, which are based on various unique chains. Their advantages and limitations are discussed. Additionally, a series of typical dynamic interactions that are used to enable autonomous self-healing in underwater environments is highlighted. Moving beyond these fundamental designs, the diverse opportunities to leverage recent synthetic advancements in water-insensitive self-healing materials for the progression of soft electronic applications are systematically discussed. Ultimately, the significant challenges and remaining opportunities to present a comprehensive view of the future development of water-insensitive self-healing materials are highlighted. This review aims to stimulate further innovation in this burgeoning and emerging field of intrinsic healable materials, interfacing with dynamic chemistry and soft electronics.     

Atomic Insights of Self-Healing in Silicon Nanowires

The self-healing capability is highly desirable in semiconductors to develop advanced devices with improved stability and longevity. In this study, the automatic self-healing in silicon nanowires is reported, which are one of the most important building blocks for high-performance semiconductor nanodevices. A recovery of fracture strength (10.1%) on fractured silicon nanowires is achieved, which is demonstrated by in situ transmission electron microscopy tensile tests. The self-healing mechanism and factors governing the self-healing efficiency are revealed by a combination of atomic-resolution characterizations and atomistic simulations. Spontaneous rebonding, atomic rearrangement, and van der Waals attraction are responsible for the self-healing in silicon nanowires. Additionally, the self-healing efficiency is affected by the fracture surface roughness, the nanowire size, the nanowire orientation, and the passivation of dangling bonds on fracture surfaces. These new findings shed light on the self-healing mechanism of silicon nanowires and provide new insights into developing high-lifetime and high-security semiconductor devices.