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路局高速信息网实际上是构建一个铁路局内部专用的“互联网”,该网络在物理上和国际互联网隔绝,充分利用互联网技术接口标准、开放、简单、便于扩容、接入成本低廉等特点为铁路信息化建设提供通道承载服务。路局高速信息网组网基于TCP/IP技术,用于实现铁路各站段到各中间站、车间、班组的办公联网系统、视频会议系统、远程监视、监测、控制系统等不同系统的接入。 相似文献
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中国政府和学术界较早地认识到建设信息高速公路对经济发展的重要作用。中国科学院院士、北京邮电大学名誉校长叶培大教授,中国科学院院士、著名通信专家陈俊亮教授,国家863高科技计划通信专家组组长、北京邮电大学副校长钟义信等教授、学者,1993年初联合向有关方面提出了“中国高速信息网计划”的构想,并把它取了一个更有特色的代号——CHINA。即“中国高速信息网计划”的英文 China High-speed Information NetworkApproach的缩写。 相似文献
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在当今信息高速发展的时代,为了适应现代网络的高速发展,公司决定独立架设企业信息网,以更快捷,更安全,更简便的方式实现信息的共享及现代智能化办公。本文对某公司的网络进行了设计。 相似文献
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百灵信息网的最大特点是“宽带、高速、无缝、稳定、安全”。在用户的接入方式上,它采用光缆到楼,双绞线入户的方式,取代了传统的电话拨号方式,用户最少可以得到10M的共享速度,有效消除了“通讯瓶颈”,622M主干、155M接入带宽使信息传输真正实现了质的飞跃。极强的兼容性可使各种网络在稳定、安全的前提下,实现高速互连、无缝接入,并使虚拟网服务得以实现,从而为社会节省巨额的网络建设费和大量的维护人 相似文献
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高校财务信息网是财务信息资源、服务与财务信息使用者之间的桥梁,是信息服务的重要工具,是提高财务工作服务水平和管理能力的基本要求.基于计算机网络技术的高校财务信息网,在高校财务管理中发挥着越来越重要的作用.本文就高校如何建设财务信息网进行了研究,探悉了财务信息网建设的内容和实际作用. 相似文献
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近年来,世界上一些发达国家掀起了建设信息高速公路热潮。我国于1993年由中国科学院院士叶培大教授等专家提出建设“中国高速信息网计划”。与此同时,邮电部门加快了通信网的建设,“八五”期间全国建成了22条国家一级干线光缆(总长达3.2万公里)、20条数字微波干线和20个大中型卫星通信地面站。全国分组交换公用数据网进行了扩容,网络覆盖了包括267个城市,拥有2万端口,通达21个省、市的高速数字数据骨干网(DDN)已投入运行,并与世界20个国家和37个分组 相似文献
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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. 相似文献
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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。 相似文献
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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. 相似文献
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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- 相似文献
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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- 相似文献
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Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
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 相似文献
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Michael Springborg 《华南师范大学学报(自然科学版)》2014,(6):136
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 相似文献
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Zhu Chaoyuan 《华南师范大学学报(自然科学版)》2014,46(6):140-140
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of 相似文献
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《上海师范大学学报(自然科学版)》2014,(5):550
<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 相似文献