Prediction of Stabilization of Ship in Random Wave

In this paper we show thc method of energy in part with which we can get the model of random wave,and predict theroll motion of unstabilized ship and stabilized ship using the wave model.The control parameters of fin stabilizer are determinedaccording to the performance index. The simulation of the system is also made in this paper. The comparison of the simulationwith real ship indicates that the method can be used in the prediction of roll motion of a stabilized ship in random wave.     

DF4D型机车飞车故障原因分析及措施

1 问题的提出 自1997年起,我段陆续配属了DF4D型内燃机车投入运输生产,现已成为我段客车运输的主型机车,担负京广线武昌至郴洲区段的全部客运列车及部分郴洲至广州区段的客运列车牵引任务.该型内燃机车投入使用以来,在1998年度共计发生11起柴油机飞车事故.现统计如表1所示.     

IL-1β、IL-6对人冠脉平滑肌细胞表达基质金属蛋白酶-3的影响

目的探讨炎症因子白介素-1β(interleukin-1β,IL-1β)、白介素-6(interleukin-6,IL-6)对人冠脉平滑肌细胞表达基质金属蛋白酶-3(matrix metalloproteinase-3,MMP-3)的影响。方法①采用20μg/L的IL-1β、10μg/L的IL-6各自刺激人冠脉平滑肌细胞,共同培养0、2、4、8、24、36 h后收集细胞;②采用不同质量浓度的IL-1β(0、5、20、40μg/L)、IL-6(0、5、10、50μg/L)刺激人冠脉平滑肌细胞,共同培养6 h后收集细胞。③应用实时荧光定量PCR方法检测细胞内MMP-3基因的表达量。结果①在同剂量IL-1β、IL-6刺激下,MMP-3的表达量在2 h时就开始发生上调,8 h达高峰,而后开始下降;②在不同剂量IL-1β、IL-6刺激下,MMP-3的表达量在实验剂量范围内随着剂量的加大呈上升趋势(IL-1β:r=0.907,P=0.000;IL-6:r=0.919,P=0.000)。各因子不同剂量组MMP-3的表达量均具有显著性差异(IL-1β:F=24.047,P=0.000;IL-6:F=14.081,P=0.001)。IL-1β20μg/L和40μg/L组间MMP-3表达量没有显著性差异(P=0.154),IL-6 5μg/L和10μg/L组间MMP-3表达量没有显著性差异(P=0.292)。结论炎症因子IL-1β、IL-6能促进冠脉平滑肌细胞中斑块稳定相关标记物MMP-3的表达,这可能是炎症在急性冠脉综合征发生发展中的重要作用机制之一。     

Development of efficient stop planning optimization process for high‐speed rail systems

The Taiwan High Speed Rail (THSR) has recently added three additional stations to its original network. Although the three additional stations can improve accessibility to the system, these new stations can present difficulties in the transportation planning process, particularly for planning of train stops. The additional stations may benefit some passengers, but may also lengthen the travel time for the other passengers. Therefore, the main challenge faced by THSR is finding an efficient way to design appropriate stopping patterns. Past studies on stop planning usually adopted meta‐heuristics or decomposition methods to solve this complex problem. Although these solution techniques can improve solution efficiency, none of them can guarantee the optimality of the solution and capture the transfer movement of different stopping patterns. In this research, we proposed an innovative network structure to address complex stop planning problems for high‐speed rail systems. Given its special network structure, two binary integer programming models were developed to simultaneously form and determine the optimal stopping patterns for real‐world THSR stop planning problems. An optimization process was also developed to accurately estimate the station transfer time corresponding to the variation in stopping patterns and passenger flow. Results of the case studies suggest that the proposed binary integer programming models exhibit superior solution quality and efficiency over existing exact optimization models. Consequently, using this stop planning optimization process can help high‐speed rail system planners in designing optimal stopping patterns that correspond to passenger demand. Copyright © 2017 John Wiley & Sons, Ltd.     

小钢管劲性骨架混凝土箱拱施工阶段受力分析

通过有限元程序ANSYS建立箱拱的空间计算模型,采用内力叠加法和应力叠加法计算施工过程中拱桥的应力和位移,对2种方法的计算结果进行了对比,阐述了2种方法的特点和适用范围,并分析了初始应力和截面刚度变化对拱桥受力的影响.     

EPS轻量土弹性波速的超声试验研究

通过超声波测试技术,对EPS轻量土的弹性波速特征进行试验研究,为开发EPS轻量土无损检测技术提供必要的依据.     

汽车主动悬架和四轮转向系统的耦合分析及协调控制

针对汽车转向系统和悬架系统的相互作用,建立了转向动力学子模型、悬架动力学子模型以及考虑两者耦合效应的综合动力学模型.通过仿真分析发现:悬架系统主要通过轮胎动载荷引起轮胎侧偏力变化,从而引起转向特性发生显著变化;而转向系统则主要通过离心力影响簧上质量的侧倾运动,从而引起悬架运动特性发生变化;主动悬架与四轮转向协调控制系统在减小车身侧倾和前轮垂直载荷波动的同时,还能有效地改善车辆横摆响应和质心侧偏角响应.     

用夯实水泥土挤密桩加固客运专线黄土地基

阐述了夯实水泥土挤密桩加固湿陷性黄土地区客运专线路基基底土的作用机理,并以郑西客运专线工程为背景,通过实测资料说明其施工工艺和质量控制方法。     

客车侧倾及侧翻安全性综合评价方法

对客车侧倾及侧翻的试验及评价方法进行介绍和分析,在此基础上提出一种主被动安全综合评价方法,为企业进行客车安全性的设计和评价提供参考。     

车用高压共轨柴油机瞬态工况微粒排放粒度分布的分析

对高压共轨柴油机稳态与瞬态工况下的微粒排放粒度分布进行了实验研究。结果表明,高压共轨柴油机排气微粒粒径大部分处于250nm以内,超细微粒占绝大多数。稳态工况下,随负荷增加微粒数量浓度分布曲线峰值逐渐向大粒径方向移动,大负荷工况下峰值开始进入积聚态区域。在瞬态工况下,微粒粒度分布曲线呈单峰形态,平均数量浓度分布峰值位于核态区域,峰值区间为15~25nm。在同一负荷(当量比0.5)下,稳态工况的核态微粒的数量、表面积和体积浓度均较稳态工况大幅度上升;随着瞬变率的增大,核态微粒数量浓度增加而积聚态微粒数量浓度下降。