两用型铁水车研制

介绍了两用型铁水车的技术参数、结构特点及其应用情况。     

基于混合补偿的同相牵引供电系统

为解决异相牵引供电方式存在的电能质量和电力机车过分相问题,将有源补偿和无源对称补偿技术相结合,提出基于平衡变压器接线方式的混合式同相牵引供电系统结构。文中给出混合式同相供电的统一补偿理论、无源补偿系统的无源元件参数计算方法、有源补偿的控制策略、无源和有源补偿的协调控制策略。最后,以采用YNvd接线方式的平衡变压器为例,采用MATLAB软件仿真验证该系统方案和控制策略的正确性。     

回龙观东站～立水桥站区间下穿城铁夯管施工技术

北京回龙观东站～立水桥站污水工程下穿城铁、国铁，所处位置特殊，地质条件复杂，地下水较为丰富，施工沉降要求高，难度大。采用夯管法施工后，有效的提高了施工质量和进度，保证了城铁、国铁的正常运营，创造了良好的经济效益。夯管法比暗挖法和顶管法更为简单快捷，更能保证施工安全。介绍了夯管法施工的特点和施工方法要点及施工中的关键问题（如夯管方向偏差、地表沉降、夯进停滞不前等）及其处理措施。     

基于区位论和城市GIS的物流园区布局研究

根据区位论和城市地理信息系统的基本内容，从市场、交通、竞争环境以及其他因素等四个方面分析影响物流园区布局的区位因素，提出基于区位论和城市GIS的物流园区区位布局二阶段模型，以某市物流园区选址布局规划为例进行实证分析并得出相关的研究结论。     

含裂纹结构剩余疲劳寿命循环J积分工程评估方法

以弹塑性断裂理论为基础,利用EPR I工程方法计算ΔJ,拟合出16Mn钢的疲劳裂纹扩展率公式,并推导出含裂纹结构剩余疲劳寿命评估的循环J积分工程计算公式,为含裂纹结构在塑性应变条件下剩余疲劳寿命评估提供一种计算方法。     

冶金企业石碴车的研制与应用

简要介绍了冶金企业厂内铁道线路铺设用的石碴及建筑废料的专用运输车辆,分析了石碴运输、装卸特点,提出了石碴车的设计思路.     

超级电容在地铁制动能量回收中的应用研究

针对机车启动、制动对直流母线电压的影响,提出一种基于超级电容的储能装置,该装置通过双向DC-DC变换器为列车提供牵引或者吸收再生制动过程的暂态能量,分析了超级电容储能系统充放电控制策略,搭建了一个750V直流电气化铁路仿真平台,仿真结果验证了超级电容储能系统能够维持直流母线电压稳定,有效地防止城市轨道交通供电系统中电力负荷波动和避免再生制动能量的浪费。     

Effect of oil shale on Na+ solidification of red mud-fly ash cementitious material

Red mud-fly ash based cementitious material mixed with different contents of oil shale calcined at 700°C is investigated in this paper. The effect of active Si and Al content on the solidification of Na⁺ during the hydration process is determined by using X-ray diffraction (XRD), ²⁷Al and ²⁹Si magic-angle-spinning nuclear magnetic resonance (MAS-NMR), infrared (IR), scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It is shown that the content of oil shale has a remarkable effect on the solidified content of Na⁺. The hydration process generates a highly reactive intermediate gel phase formed by co-polymerisation of individual alumina and silicate species. This kind of gel is primarily considered as 3D framework of SiO₄ and AlO₄ tetrahedra interlinked by the shared oxygen atoms randomly. The negative charges and four-coordinated Al inside the network are mainly charge-balanced by Na⁺. The solidifying mechanism of Na⁺ is greatly attributed to the forming of this kind of gel.     

三相V/V牵引变压器励磁涌流的识别

牵引变压器差动保护的关键问题是如何有效识别励磁涌流与故障电流.等效瞬时电感算法能从本质上反映变压器的运行状态,能够准确识别励磁涌流与故障电流.对于三相V/V牵引变压器,其接线形式特殊,运行环境恶劣,二次谐波制动判据往往不能有效闭锁.目前,等效瞬时电感算法已经很普遍地应用于电力变压器,但该算法还没有应用于三相V/V牵引变压器识别励磁涌流和故障电流.本文对现有的等效瞬时电感算法的计算条件和运算单元进行修正,通过计算非饱和区等效瞬时电感的平均值识别三相V/V牵引变压器的励磁涌流与故障电流.通过动模实验验证算法的有效性,实现对励磁涌流与匝间短路的可靠识别,并具有抗电流互感器饱和的特性.     

Phase transitions relating to the pozzolanic activity of electrolytic manganese residue during calcination

Electrolytic manganese residue（EMR） is generated from electrolytic manganese metal（EMM） industry, and its disposal is currently a serious problem in China.The EMR were calcined in the interval 100—900℃to enhance their pozzolanic activity and characterized by the differential thermal analysis-thermogravimetry（TGDTA）, X-ray diffraction（XRD）,infra-red（IR） and chemical analysis techniques with the aim to correlate phase transitions and structural features with the pozzolanic activity of calcined EMR.Prom the phase analysis and compressive strength results,it is found that the EMR calcined within 700—800℃had the best pozzolanic activity due to the decomposition of poorly-crystallized CaSO₄ under the reducing ambient created by the decomposition of（NH₄）₂SO₄.The appearance of reactive CaO mainly contributes to the good pozzolanic activity of EMR calcined within 700—800℃.The crystallinity of Mn₃CO₄ increases leading an unfavourable effect on the pozzolanic behaviour of EMR calcined at 900℃.The developed pozzolanic material containing 30%（mass fraction） EMR possesses compressive strength properties at a level similar to 42.5^# normal Portland cement,in the range of 41.5—50.5 MPa.Besides,leaching results show that EMR blend cement pastes have excellent effect on the solidification of heavy metals.