高原型轨道车动力装置及传动方式的选型研究

为配合国家西部大开发 ,更好地为青藏铁路建设和未来青藏铁路运营、维修、抢险提供可靠、适用、便捷的轨道车辆设备。本文就解决轨道车在高海拔、低气压、缺氧、低气温、风沙大等特殊工作环境下其动力装置和传动方式选型的技术问题进行了研究、论证、分析和总结。     

大跨度先张法折线配筋预应力混凝土简支梁预制施工技术

24 m折线配筋先张法预应力混凝土简支梁是国内首次采用的新型结构,是青藏线采用的新技术之一,其技术含量高、施工工艺新、施工难度大、在国内尚属首次生产,根据工艺特点和施工要求,施工中预应力施工工艺、耐久性混凝土施工控制值得推广和研究。     

大跨度悬索桥施工猫道抗风稳定性分析

为了保证大跨度悬索桥施工猫道的抗风安全,通过风洞试验对悬索桥施工猫道进行了动力特性和抗风稳定性分析,结果表明,虽然没有采取设置抗风索的措施来提高猫道的抗风稳定性,但仍然具有良好的抗风稳定能力。     

浅谈铁路电气化工程项目的成本控制

加强工程项目的成本控制,是一个工程企业实现利润最大化、获得理想的经济效益的根本途径。本文分析了项目成本控制的主要环节,结合工程实践提出了项目成本的控制措施、方法及成本控制中应注意的几个问题。     

Bond Graphs for Vehicle Dynamics

For the purposes of analyzing the stability and control properties of aircraft, automobiles, and ships, it is convenient to idealize the vehicle as a rigid body and to use a body-centered coordinate frame. A six-port bond graph is first developed which represents the nonlinear dynamics of a rigid body in a coordinate system rotating with the body. It is then shown how the graph simplifies if only lateral or longitudinal dynamics are studied. Finally, bond graphs for the type of stability studies in which the assumption of small perturbations permits linearization are shown for elementary models of automobiles and aircraft.     

南京地铁暗挖隧道防水设计与施工技术

本文结合工程实际，就南京地铁暗挖隧道防水设计与施工技术进行了探讨，为今后类似工程提供参考。     

Power Requirements for Traversing Uneven Roadways

Vehicles which travel on uneven roadways or rough surfaces require power beyond that associated with air drag, rolling resistance or other sources of friction even though kinetic and potential energy may be conserved on the average. This is true because damped relative motions within the vehicle dissipate energy, and, even for nearly rigid vehicles, energy is lost at impact with the ground whenever the vehicle loses contact with the ground surface due to the finite downward acceleration of gravity.

Using elementary vehicle models, the nature and magnitude of the component of propulsive force associated with these energy loss mechanisms is estimated. In certain speed ranges, this force is found to vary dramatically with speed for several types of periodic roadway profiles studied. While the force due to unevennesss may be small compared to other forces for high-speed vehicles operating on smooth surfaces, it can be the major source of required power for off-road vehicles operating on very rough terrain.     

麦秸秆加筋石灰土抗剪强度影响因素灰色关联度分析

为增强石灰固化滨海盐渍土的强度、塑性和抗变形能力,进行了麦秸秆加筋辅助处理的试验。试验分析结果表明:①麦秸秆加筋作用主要提高土的粘聚力,对内摩擦角的影响很小。②适宜的麦秸秆加筋长度为20mm,约为试样直径的1/3;适宜的加筋率为0.25%。③养护初期麦秸秆加筋作用较强,养护后期,土的强度提高主要依赖石灰的固化作用。④灰色关联度理论分析认为,对加筋土的粘聚力影响程度依次为固化作用、加筋率、加筋长度;对内摩擦角影响程度依次为固化作用、加筋长度、加筋率。固化作用是影响加筋土强度的主要指标。麦秸秆     

点线啮合齿轮二级减速器的速比分配

推导了点线啮合齿轮二级减速器接触强度和弯曲强度相等的公式,计算出其理论值,并推荐了系列减速器的分配方案：对于软齿面和中硬齿面,宜采用接触等强度的系列;对于硬齿面,宜采用弯曲等强度系列.渐开线齿轮推荐的系列并不适用于点线啮合齿轮.     

热挤压与退火处理后SiO2/Mg复合材料的织构研究

采用金相显微镜和XRD衍射技术对Si02/Mg复合材料微观组织和Mg基体的织构在热挤压和退火处理中的演化规律进行了分析.结果表明,SiO2/Mg复合材料在400℃挤压过程中发生再结晶,基体形成〈 1010 〉//ED纤维织构.经450℃×30 min退火后,{0002}极密度最大值由退火前的60提高到72,而{1010}和{ 1120}极密度最大值较退火前略有下降.