面向10G城域以太网带宽管理的RPR技术

弹性分组环(RPR：resilient packet ring)是当前比较热门的组网技术，它为10G城域以太网提供了一个很好的组网方案。从RPR在10G城域以太网带宽管理方面的优势出发，介绍了其技术特点、标准化及产业化现状，讨论了城域以太网的RPR提案中有利于带宽管理的各种关键技术。     

10 G城域以太网的RPR组网及其带宽管理技术

随着现今网络应用的快速发展,用户对带宽的需求日益增大,骨干网和接入网的技术革新又使旧城域网成为网络发展的瓶颈,因此建设新一代城域网已成为各个设备制造商抢占市场的先机, 是运营商拓展业务的重中之重。在介绍了城域网进行改革性建设的必要性、紧迫性以及弹性分组环（RPR）组网技术后, 阐述了10 G以太网作为新一代的全光城域网络传送技术的优势和RPR在10 G城域网以太网组网建设中的优势,探索了RPR的带宽管理技术,并提出了RPR环路带宽共享接入策略和公平接入的构想。     

10G城域以太网的RPR组网及其带宽管理技术

随着现今网络应用的快速发展，用户对带宽的需求日益增大，骨干网和接入网的技术革新又使旧城域网成为网络发展的瓶颈，因此建设新一代城域网已成为各个设备制造商抢占市场的先机，是运营商拓展业务的重中之重。在介绍了城域网进行改革性建设的必要性、紧迫性以及弹性分组环（RPR）组网技术后，阐述了10G以太网作为新一代的全光城域网络传送技术的优势和RPR在10G城域网以太网组网建设中的优势．探索了RPR的带宽管理技术，并提出了RPR环路带宽共享接入策略和公平接入的构想。     

基于高速以太网技术的应用探讨

高速以太网技术以其速度快、带宽高且兼容性好,比传统标准以太网更具有强大的功能,是目前计算机高速网络的一个新的领域.本文针对高速以太网技术的重要方面,着重讨论了千兆以太网和万兆以太网相互存在的技术特点,及10 GbE与弹性分组数据环(RPR)结合产生的10 G RPR技术,为高速以太网的组网提供了依据.     

城域传输网的技术特点及演进方案

为适应目前多业务传送的需要,升级以SDH为基础的城域传输网,采用对比优缺点的方法,分析了城域传送网的组网现状,以及光纤直连组网,多业务传送平台技术(MSTP)、城域波分DWDM以及弹性分组环RPR的优点和局限性,阐明了采用以MSTP设备为主,城域DWDM设备为辅．逐步发展RPR设备的组网方案,实现了网络的平滑升级,有效地保护运营商的当前投入。     

基于城域网的弹性分组环技术

弹性分组环(RPR)技术结合以太网技术和SDH技术所带来的组合优势,适合于城域网的组网。文章介绍了RPR的网络体系结构、MAC层机制,分析了RPR的技术特点,用实例说明了RPR技术在校园城域网中的优势。     

面向3G和全业务运营的绍兴移动PTN组网研究与实现

PTN组网是城域传输网实现3G及全业务统一承载的先进组网模型,目前已成为各大移动运营商建设下一代中小型城域传输网的重要解决方案。提出了面向3G和全业务运营的绍兴移动PTN+OTN组网思路和实现方案。     

RPR业务分类在传输网管中的实现

RPR是一种新的MAC层协议和城域网技术,具有空间复用、带宽动态分配、支持业务级别等主要特点,实现采用的是三层结构.讨论了传输网管系统中实现RPR业务分类涉及到的3条Qx接口命令的处理：设置数据板以太网业务属性、设置数据板静态目的站点地址、设置RPR端口环选择.     

弹性分组环技术（RPR）

弹性分组环(RPR)技术是一种基于以太网技术和标记交换技术相结合的，多业务共存的业务特性的新一代城域网解决方案。主要介绍了弹性分组环(RPR)的MAC协议帧结构，探讨了RPR的基本原理、关键技术和光以太网RPR，并对RPR技术在未来通信网中的发展趋势进行了分析。     

两级10G EPON系统物理层方案研究

文中主要探讨了一种基于10G EPON的TDM/WDM混合组网方案：在原OLT和ONU之间插入Sub-OLT,在OLT和Sub-OLT之间采用WDM-PON技术,以10G对称速率组网;考虑到节约成本和实现推迟ONU升级的目的,在Sub-OLT和ONU之间则仍采用标准的1G EPON（TDM/TDMA技术）组网.OptiSystem的建模仿真结果表明,该方案既能保持与IEEE802.3/802.3av最大的兼容性,又能够在满足带宽增长的前提下取得成本-效益的最大化.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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