系统分析青藏铁路自然条件对高原铁路大型养路机械的影响

借鉴施工人员现场试验和文献资料,归纳总结青藏铁路特殊气候条件,分析在电气系统、发动机、供氧系统、液压系统等方面必须解决的难点和为改善舒适性、安全性和可靠性所要面对的问题,提出在设计中采用改进高原大型养路机械的有效措施。可对我国高原铁路的养护设计与装备的研究开发提供参考价值和指导作用。     

新建地铁线穿越运营地铁线的评估方法研究

通过对新建地铁线穿越运营地铁线的评估内容、思路、步骤以及计算假定的系统研究,建立了新建地铁线路穿越运营地铁线路的评估方法,并将该方法应用于某新建地铁站换乘厅侧穿地铁运营区间喇叭口结构的评估中.评估结果表明:该方法在评估新建地铁线穿越运营地铁线中具有一定的适用性,并可为新建地铁线穿越周边建筑物、桥梁或管线等评估提供参考.     

QS-650型全断面道砟清筛机提速动力转向架的研制

介绍了QS-650型全断面道砟清筛机120 km/h提速动力转向架技术改造,在设计过程中对提速动力转向架的零部件强度进行了理论计算,对配装提速动力转向架的QS-650型清筛机进行了线路动力学试验,结果表明该转向架具有较好的运用可靠性和整车动力学性能.     

高速客车车体钢结构模态分析探讨

有限元技术的日益成熟和发展,为高速客车车体钢结构的开发、设计提供了可靠的模态参数,为车身设计具有良好动态特性提供了保障。本文论述了有限元法在车体钢结构模态分析和车体动态特性研究中的应用;详细介绍有限元模态分析的理论基础和车体钢结构有限元模型的建立准则;通过对有限元模型计算结果的分析,解决模态分析中存在的问题参数,从而提高车体钢结构的动态性能。     

EFFECTS OF FILTER MEMBRANES ADSORBING INFLAMMATORY MEDIATORS IN HEMOFILTRATION

Sepsisischaracterizedbyreleaseofexcessiveamountofproinflammatorycytokinesinthecircu lation ,leadingtoa generalizedanduncontrolledhostresponse .Aconsiderablenumberofexperimen talandclinicalinvestigatorshavereportedemploy inghemofiltration (HF)toeliminatecytokinesandchemokines .Thisexcessiveinflammatoryresponsecouldbedownregulatedwithremovalofcytokinesandothermediators .Thesedatashowedthatthemechanismofmediatorseliminationwaslinkedtoconvectionandadsorptionbyhemofiltration .Ad sorptionappearstob…     

隧道坡度因素对柴油车烟雾排放量的影响

通过发动机台架模拟 ,控制吸入气缸一定废气量而营造隧道污染环境 ,进行柴油车在实际道路坡度运行时动态烟雾排放测试 ,以及在实际隧道环境下 ,柴油车坡度运行时动态烟雾排放测试 ,获得在不同坡度环境下柴油车烟雾排放的道路实测数据。结果分析表明 ,随着道路坡度的增加 ,柴油车烟雾排放量急剧上升 ,而在相同坡度下 ,车速越高烟雾排放量越大 ,且隧道内坡度每增加1 % ,柴油车烟雾排放量大约增加 70 %～ 1 2 0 %。     

LEISHMANIA PROMASTIGOTES EVADE INTERLEUKIN 12 INDUCTION BY MACROPHAGES AND STIMULATE A BROAD RANGE OF CYTOKINES FROM CD_（4）~（＋

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Modeling delay at signalized intersections with channelized right‐turn lanes considering the impact of blockage

This paper presents a probabilistic delay model for signalized intersections with right‐turn channelization lanes considering the possibility of blockage. Right‐turn channelization is used to improve the capacity and to reduce delay at busy intersections with a lot of right‐turns. However, under heavy traffic conditions the through vehicles will likely block the channelization entrance that accrues delay to right‐turn vehicles. If the right‐turn channelization gets blocked frequently, its advantage in reducing the intersection delay is neglected and as a result the channelization lane becomes inefficient and redundant. The Highway Capacity Manual (HCM) neglects the blockage effect, which may be a reason for low efficiency during peak hours. More importantly, using HCM or other standard traffic control methods without considering the blockage effects would lead to underestimation of the delay. To overcome this issue, the authors proposed delay models by taking into account both deterministic and random aspects of vehicles arrival patterns at signalized intersections. The proposed delay model was validated through VISSIM, a microscopic simulation model. The results showed that the proposed model is very precise and accurately estimates the delay. In addition, it was found that the length of short‐lane section and proportion of right‐turn and through traffic significantly influence the approach delay. For operational purposes, the authors provided a step‐by‐step delay calculation process and presented approach delay estimates for different sets of traffic volumes, signal settings, and short‐lane section lengths. The delay estimates would be useful in evaluating adequacy of the current lengths, identifying the options of extending the short‐lane section length, or changing signal timing to reduce the likelihood of blockage. Copyright © 2016 John Wiley & Sons, Ltd.     

A survey of wheel–rail contact models for rail vehicles

Accurate and efficient contact models for wheel–rail interaction are essential for the study of the dynamic behaviour of a railway vehicle. Assessment of the contact forces and moments, as well as contact geometry provide a fundamental foundation for such tasks as design of braking and traction control systems, prediction of wheel and rail wear, and evaluation of ride safety and comfort. This paper discusses the evolution and the current state of the theories for solving the wheel–rail contact problem for rolling stock. The well-known theories for modelling both normal contact (Hertzian and non-Hertzian) and tangential contact (Kalker's linear theory, FASTSIM, CONTACT, Polach's theory, etc.) are reviewed. The paper discusses the simplifying assumptions for developing these models and compares their functionality. The experimental studies for evaluation of contact models are also reviewed. This paper concludes with discussing open areas in contact mechanics that require further research for developing better models to represent the wheel–rail interaction.