城际轨道交通列车故障救援模式的探讨

城际轨道交通系统出现车辆故障失去动力时,尽快进行救援、恢复正常运营是运营管理工作的一项重要内容.从分析城际铁路的运营特点出发,在借鉴城市轨道交通经验的基础上,探讨了城际轨道交通列车故障救援时间、救援速度、救援设备分布之间的关系.对比分析了三种可能的救援模式下救援状态的持续时间以及对正常运营的干扰程度,为城际铁路设计和运...     

锦屏二级水电站特大断面隧洞围岩稳定性研究

以超埋深、高地应力条件下的锦屏二级水电站隧洞施工为背景,对特大断面隧洞开挖围岩稳定性进行研究.依据围岩地质和断面形状与尺寸,结合隧道工程理论与方法,确定了监测断面并在各断面安装埋设了锚杆应力计、多点变位计和反射膜片,通过对TBM组装洞现场监测并对实测数据进行分析,得出了施工过程中围岩应力和位移及其变化规律.结果表明,围岩的应力和变形都在可以接受的范围内,处于稳定状态.说明施工方法、作业顺序和支护形式及其参数是合理的,能够保证在恶劣条件下开挖时围岩的稳定以及地下结构安全.     

物流案例(4)

怀俄莫购买者合作社 怀俄莫购买者合作社设在蒙大拿州的别林斯(Billings,Montana),为当地大约150家食品杂货店提供干杂货和土产,其范围从北面的大瀑布(Great Falls)到百特(Butte),西南面从卡斯伯(Casper)到切亚尼(Cheyenne).所有干杂货都从该合作社(1968年建造在别林斯)的一座20 000平方英尺的仓库和在大瀑布和切亚尼的小型租赁仓库里运出来.在这些仓库里,合作社把某些散装货物,例如土豆、大蒜、橘子等打包成5磅、10磅和20磅重的袋装货.仓库还储存商店用的物品,如肉类包装纸、出纳机纸带、土产塑料袋和各种大小的牛皮纸.     

中国汽车产业国际竞争力实证分析

基于产业国际竞争力理论,从影响因素角度建立了中国汽车产业国际竞争力评价指标体系.通过问卷调查、定性和定量分析方法,评价中国汽车产业国际竞争力处于较低水平,在外部产业环境、资产利润率、产品价格等方面有优势,在人口素质程度、研发、海外市场等方面处于弱势；并且分析了造成中国汽车产业国际竞争力水平较低的主要原因.     

平凡中见英雄

噩耗传来，认识杨庆文的朋友和同事们无不痛心疾首，惋惜之情无以言表。行业和地方媒体先后刊登了杨庆文的事迹报道。一个平凡的海事英雄就这样跃然纸上，他就是我们生活中的英雄。     

加强客车生产过程质量控制

分析客车企业生产过程中质量控制的难点，提出有关控制方法，从而提高产品过程质量。     

《2006年海事劳工公约》解读系列之四海员的就业条件

1、<公约>标题二阐述了哪些要求? 国际劳工组织(简称ILO)在<2006年海事劳工公约>(简称<公约>)标题二中,阐述了海员就业条件的八个方面要求:海员就业协议、工资、工作时间和休息时间、休假的权利、遣返、船舶灭失或沉没时对海员的赔偿、a配员水平、海员职业发展和技能开发及就业机会等.标题二中规则2.1至2.8及相应守则的规定,阐明了ILO各成员国、船东对于海员就业所应承担的责任、义务以及实践的方式,对于规范和发展稳定的海事劳动关系,在国际层面提出有关各方均需遵循的规定.     

基于DSP的嵌入式协议栈的研究和实现

通过分析以DSP为处理器的嵌入式系统中协议栈的应用,给出基于DSP的嵌入式TCP/IP协议栈的实现方案,设计嵌入式通信协议模型、总体结构和各个协议工作的主要流程,在DSP上对TCP/IP协议栈进行了设计,实现ARP,IP,ICMP,UDP协议.     

General Construction Technology Scheme of Tianshan Shengli Tunnel on Urumqi-Yuli Expressway北大核心CSCD

With a total length of about 22 km, Tianshan Shengli Tunnel on Urumqi-Yuli Expressway is currently the longest expressway tunnel under construction in the world. It adopts the construction scheme of "3 tunnels (2 D& B main tunnels and 1 TBM-driven middle pilot tunnel) + 4 shafts", which is characterized by great construction difficulty and high technical standard requirements. The tunnel construction is faced with technical challenges such as TBM passing through large fault fracture zones, long-distance construction ventilation in three tunnels, deep and large shaft construction and logistics organization in two-main tunnel construction assisted by middle pilot tunnel. In the parallel three-tunnel method design of Tianshan Shengli Tunnel, the TBM-driven middle pilot tunnel can not only play the role of advanced pilot tunnel, but also assist the construction of the two main tunnels and speed up the construction progress. For the middle pilot tunnel, the TBM excavation diameter is 8.4 m, and the initial support is designed as 100% force-bearing capacity in construction period, which can meet the requirements for two-way material transportation, ventilation and belt mucking in the pilot tunnel. Vault suspension scheme is adopted for the continuous belt conveyor, which can reduce the impact on the material flow organization in the cross passages. Multifunctional service vehicles (MSVs) independently developed by CCCC Group are used for the transportation of TBM materials and prefabricated inverted arch blocks, which can realize double-headed driving. TBM will pass through two large fault fracture zones F6 and F7. According to the stability of the surrounding rock at the tunnel face, the targeted treatment measures would be adopted. If necessary, the scheme of "steel segment + extruded concrete" shall be used for the initial support. In case of serious machine jamming or rock collapse, the heading expansion excavation method or bypass heading method shall be used. Tianshan Shengli Tunnel adopts phased forced ventilation option, and the ventilation mode is designed in stages with the change of tunnel construction stage. The fans and air pipes used are imported ones, and a ventilation management team is set up to strengthen ventilation management and ensure ventilation quality. Highly mechanized construction is used for the two D& B main tunnels, the application of equipment such as three-arm rock drilling jumbo and wet shotcrete machine is promoted, so as to reduce the number of workers and labor intensity, and improve work efficiency. The deep shafts of Tianshan Shengli Tunnel are constructed by short-section excavation and lining mixed operation method, and the initial support is lined by formwork pouring concrete, so as to realize safe and rapid excavation. According to the research results, the construction technology scheme for Tianshan Shengli Tunnel can meet the needs of tunnel construction. The research results can be directly used to guide the construction of Tianshan Shengli Tunnel, and provide reference for the construction of extra long highway tunnels in high-altitude areas. © 2022, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

雷达数据无损压缩研究

总结雷达信号的特点,对常用的雷达数据压缩方法进行分类,并给出评价指标.介绍雷达无损压缩中的统计、预测、变换编码方法,对每种方法均给出较为典型的实例.最后,结合评价指标,对各种算法进行比较.