国外高速铁路弓网关系及磨耗试验台介绍

京津城际铁路的开通标志着我国已进入高速铁路时代,对高速电气化铁路弓网关系的基础理论研究和产品试验研发迫在眉睫,为此急需建立我国的高速弓网关系及磨耗试验台。通过对国外试验台的介绍,希望对国内同行有所帮助,建好中国铁路的高速弓网关系及磨耗试验台。     

HXD1B型机车转向架构架制造工艺分析

对HXD1B型六轴机车转向架构架梁体焊接工艺补偿量、侧梁焊接和构架整体加工等构架制造工艺的难点和重点进行介绍、分析,制定了可行的六轴机车转向架构架制造工艺,有效的确保了HXD1B型六轴机车转向架构架制造质量。     

解析列车冒进信号或越过警冲标事故构成条件

列车冒进信号或越过警冲标事故的构成条件在《铁路交通事故调查处理规则》中有明确规定,但是在分析某一具体情况是否构成本项事故时,还需要紧扣《铁路技术管理规程》,以相关条文为依据,才能准确定性。     

复合锚杆桩在大跨地下通道穿越桥桩中的应用

北京CBD地区银泰-航华地下过街通道主通道(以下简称主通道)穿越既有国贸桥南段,主通道的施工不可避免地会对邻近既有桥梁桩基产生扰动.为保证既有桥梁结构的正常使用和结构安全,对影响范围的国贸桥桩采取复合锚杆桩的保护措施,从而严格控制主通道施工引起桥梁结构的附加沉降.通过计算分析主通道的施工对既有国贸桥桥桩的影响,并结合主通道施工的实际监测资料,表明采用复合锚杆桩加固国贸桥桩基的措施是安全可靠的.     

Initial pre-stress finding and structural behaviors analysis of cable net based on linear adjustment theory

The tensile cable-strut structure is a self-equilibrate pre-stressed system. The initial pre-stress calculation is the fundamental structural analysis. A new numerical procedure was developed. The force density method is the cornerstone of analytical formula, and then introduced into linear adjustment theory;the least square least norm solution, the optimized initial pre-stress, is yielded. The initial pre-stress and structural performances of a particular single-layer saddle-shaped cable-net structure were analyzed with the developed method, which is proved to be efficient and correct. The modal analyses were performed with respect to various pre-stress levels. Finally, the structural performances were investigated comprehensively.     

绵阳机场强夯影响深度及有效加固深度研究

通过绵阳南郊机场强夯加固处理机理的分析,提出了卵砾石填筑地基强夯影响深度及有效加固深度的经验计算公式。研究结果表明:强夯法适用于处理卵砾石填土地基,所提出的经验公式计算卵砾石土层的强夯有效加固深度具有很好的适用性。     

大容量快速公交系统(BRT)路面结构组合方案研究

该文结合北京市南中轴路大容量快速公交系统示范工程的实例,对其路面结构组合设计、施工、运营使用等情况进行跟踪总结。从多方面分析车站沥青路面出现车辙的原因,有针对性地提出所采取的处理措施和具体方案,并提出建议的路面结构组合方案,对类似工程的建设具有一定的参考价值。     

Prospective randomized trial of surgery combined with preoperative and postoperative radiotherapy for rectal carcinoma

Objective To assess the effect of surgery combined with preoperative and postoperative radiotherapy ("sandwich" treatment) in rectal carcinoma. Methods From October 1990 to January 2002, 260 patients with stage Ⅱ (117 patients) and stage Ⅲ (143 patients) rectal carcinoma were randomly divided into three groups: "sandwich" group (92 patients, group A), postoperative radiotherapy group (98 patients, Group B) and operation group (70 patients, Group C). The preoperative accelerated hyperfractionation (15 Gy/6f/3d) was given for "sandwich" group which was followed by conventional postoperative fractionation (DT 35 - 40 Gy/3.5 - 4 weeks). Patients in Group B were given postoperative radiotherapy (Dr 50 Gy/5 weeks). Patients treated with surgery alone served as control. Results The local recurrence rates of Group A, B and C were 5.4% (5/92), 16.3% (16/98) and 64.3% (45/70), respectively (X2 =5.726, P=0.017); and the distant metastasis rates were 6.5% (6/92), 28. 6%(28/98) and 31.4%(22/70), respectively (X2 =15. 703, P= 0. 001). The 3-ycar survival rate was 86. 9%(80/92), 62.2%(61/98) and 51.4%(36/70), respectively (X2 =15. 141, P=0. 001). The 5-year survival rate was 68. 5%(63/92), 54.1%(54/98)and 41.4%(29/70), respectively (X2 =4. 218, P=0.04). The Ⅰ and Ⅱ grades of radiation entero-colitis in Group A and Group B were 7.6% (7/92) and 6.1% (6/98), respectively (X2 = 0. 164, P= 0. 685). Conclusion Surgery combined with preoperative and postoperative radiotherapy can improve the survival rate and reduce the local recurrence rate in rectal carcinoma patients with stage Duke's B (Ⅱ) and C (Ⅲ).     

北京市动态交通信息服务系统建设及制约因素

为探讨当前我国动态交通信息服务的制约因素和发展方向,在北京市实际研究和建设经验的基础上,结合采集交通信息准确性验证、交通信息发布内容以及标准化和产业化建设这三个制约动态交通信息服务发展的因素,分别阐述其发展现状及存在的问题,重点提出浮动车数据验证方法及北京市部分验证结论、动态交通信息发布内容基本原则和发展思路、标准化和产业化建设的机制,为我国动态交通信息采集、处理、发布技术的研发和信息服务系统的建设提供参考。