CRH6A-A型短编城际动车组牵引变流器设计

短编(通常为4辆)城际动车组相较于标准8辆动车组动车数较少,牵引变流器故障损失动力时会对车辆运营造成更严重的影响。首先介绍一种采用主辅充一体化设计理念的大功率水冷牵引变流器,包括其主电路设计、工作原理和总体结构。然后对可单重运行四象限整流器、冷却系统等重点技术进行分析。试验与实际运营表明,该牵引变流器的技术性能能够满足大功率短编城际动车组的应用要求。     

从电缆中拾取信号的工艺方法

本文提出了一种从连接在装备上的封闭的电缆中,拾取每一根导线中流经的电信息的工艺方法。详细介绍了电缆绝缘信息环的"一环两套"的组成、制作的具体工艺流程和原理样品的实物图片。该发明直接在电缆上搭建了一个对流经电缆的各种信号可随时进行检测、监控的平台,工艺方法新颖、简单、实用,普遍适用于从电缆中进行动态信号的采集。     

Study on J-integral with SENB specimensin a condenser material

A series of tests was performed with three-point single-edge-notched-bend (SENB) specimens in a condenser material (Titanium alloy). Results show that the J-integral values of welded joint and HAZ are obviously smaller than those of the base metal. It signifies that the welding process can result in a reduced toughness of Titanium alloy and the effect of crack orientation on toughness value is not negligible for engineering applications. Besides, the J-integral values of L-T direction specimens are much higher than those of LS ones. The J-integral values of rolled ring are: J_(C-R)>J_(C-L)>J_(L-R).     

自进式锚杆超前短管棚施工技术

结合大河湾隧道自进式锚杆超前短管棚施工技术的成功应用,通过和长大管棚的对比,阐述了在块(碎)石、砾石土层中施工时,自进式锚杆作为超前支护的优点。     

高海拔条件下气压焊焊接工艺的探讨

在青藏线铺设无缝线路,对提高行车质量、减少线路维修更具现实意义。通过在海拔高度4300m处的一系列施焊试验,确定了适合低气压、低含氧量处的氧气、乙炔流及加热器的火焰强度等焊接参数。     

内燃机车管系统切割的优化组合

东风4型内燃机车的管系统由燃油、机油、冷却水、空气制动等子系统组成.其材料规格多,数量多,用经验法切割下料,原材料平均利用率仅为86.5%;采用优化组合方法进行切割,可使原材料平均利用率提高到99.1%.     

以活性磷酸钙为分散剂制备苯乙烯白球

以活性磷酸钙(TCP)为主分散剂悬浮聚合制备苯乙烯白球,研究了磷酸钙用量及投加方式对白球粒度的影响,采用磷酸钙-有机高分子复合分散体系制得外观质量较好的白球珠粒。     

潜艇模拟密闭舱大气控制实验室温湿度的检测

潜艇模拟密闭舱室大气控制系统是艇员的生命支持系统,温湿度的控制显得尤为重要。通过对潜艇模拟密闭舱实验室温、湿度的检测,发现了模拟密闭舱保温结构上存在的一些问题,针对问题提出了加强保温结构的改进措施,以保证模拟密闭舱满足设计指标。     

Law enforcement in the ocean

The combating of the present great variety of criminal activities occurring at sea mainly involves measures to be taken on land, in particular in ports.However, also actual enforcement at sea will continue to play an essential (complementary) role. This article surveys the rules of international law governing law enforcement measures at sea. These rules are complex, because distinctions have to be made between the various jurisdictional zones at sea and between the positions of the flag state, the coastal state and the port state. Traditionally, ships in the high seas (all sea areas beyond a narrow band of territorial sea) were under the exclusive jurisdiction of the flag state. In an increasing number of situations, the coastal state now has law enforcement authority over foreign ships in expanded areas up to 200 nautical miles offshore. But apart from these situations, flag state jurisdiction still prevails beyond the territorial sea. This makes effective law enforcement difficult. In practice, many obstacles can be overcome by making more effective use of the authority of the port state, and by concluding new international agreements providing for specific enforcement systems.     

袋装砂井法在滨海软土地基加固中的应用

结合朔黄铁路肃黄DK589 700~DK590 400段盐渍土软土地基施工,介绍采用袋装砂井和砂垫层进行排水固结,效果良好,运营后路基稳固,线路状态良好,为今后类似工程提供借鉴经验。