内河航道横流对船舶航行的影响

为了使船舶能安全通过航道内的横流区域,利用水槽进行遥控自航船模试验,提出了内河航道横流对船舶航行横漂速度、漂角、航迹带宽度和漂距影响的经验公式,分析了Ⅳ与Ⅴ级航道横向流速的限值范围。分析结果表明:横流对船舶航行的影响程度主要与对岸航速成反比,与横流的大小及区域长度成正比,与船型大小(航道等级)成反比,同时与驾驶员的航行经验和初始船位有关;在限制航路航行方式过程中,Ⅳ与Ⅴ级航道对岸航速为2、3、4m·s-1时,可克服的一个船长内横流限值为0.48、0.58、0.70m·s-1。     

Measurements of car-body lateral vibration induced by high-speed trains negotiating complex terrain sections under strong wind conditions

Assessment of the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions is very important for research into the operation safety and comfort of passengers on high-speed trains. To assess the vibration of high-speed trains negotiating complex sections of terrain under strong wind conditions, we performed a field measurement when the train passes through typical sections of complex terrain along the Lanzhou–Xinjiang high-speed railway in China. We selected the lateral vibration conditions, including the roll angle and lateral displacement of car-body gravity centre through two typical representative sections (embankment–tunnel–embankment and embankment–rectangular transition–cutting) for analysis. The results show that the severe car-swaying phenomenon occurs when the high-speed train moves through the test section, and the car-body lateral vibration characteristic is related significantly to the state of the terrain and topography along the railway. The main causes for this car-swaying phenomenon may be the transitions between different windproof structures, and the greater the scale of the transition region between different windproof structures or landform changes, the more obvious the car-swaying phenomenon becomes. The lateral vibration of the car-body is relatively steady when the train is running through terrain with minor changes in topography, such as the windbreak installed on the bridge and embankment, but the tail car sways more violently than the head car. When the vehicle runs from the windbreak installed on the embankment into the tunnel (or in the opposite direction), the tail car sways more intensely than the head car, and the head car runs relatively stable in the tunnel.     

Effect of handling characteristics on minimum time cornering with torque vectoring

In this paper, the effect of both passive and actively-modified vehicle handling characteristics on minimum time manoeuvring for vehicles with 4-wheel torque vectoring (TV) capability is studied. First, a baseline optimal TV strategy is sought, independent of any causal control law. An optimal control problem (OCP) is initially formulated considering 4 independent wheel torque inputs, together with the steering angle rate, as the control variables. Using this formulation, the performance benefit using TV against an electric drive train with a fixed torque distribution, is demonstrated. The sensitivity of TV-controlled manoeuvre time to the passive understeer gradient of the vehicle is then studied. A second formulation of the OCP is introduced where a closed-loop TV controller is incorporated into the system dynamics of the OCP. This formulation allows the effect of actively modifying a vehicle's handling characteristic via TV on its minimum time cornering performance of the vehicle to be assessed. In particular, the effect of the target understeer gradient as the key tuning parameter of the literature-standard steady-state linear single-track model yaw rate reference is analysed.     

共轨柴油机燃烧纯生物柴油的试验研究

对一台国产涡轮增压直喷柴油机燃烧0#柴油和纯生物柴油的动力性、燃油经济性和排放性能进行对比试验研究。试验结果表明,在柴油机不进行任何调整的情况下,燃烧纯生物柴油会降低其动力性和燃油经济性,但可大幅度改善CO、HC和PM的排放性能。     

无人机技术在长江海事监管中的应用

为了打造长江干线全方位覆盖、全天候运行、具备快速反应能力的现代化水上安全监管和应急救助体系,将无人机技术引入海事监管过程当中。分析无人机应用于海事监管的优势,并研究其应用于海事监管的可行性。拓展无人机在海事监管业务中的应用,提出长江海事无人机系统建设思路。系统的建设分为实验阶段、大规模实施阶段和网络建设和应用阶段,目标是建成水-岸-空海事立体监管系统,提升长江海事监管水平。     

超前地质预报在隧道施工中的应用

超前地质预报作为隧道工程施工过程中规避施工风险的一项重要保证手段，已被广泛运用。结合宜万铁路复杂隧道的超前地质预报工作实施情况，讨论了超前预报重点、方法选择、预报效果及应注意的问题。     

大鼠糖尿病痛过敏模型的建立

用腹腔注射链尿佐菌素（ＳＴＺ）建立糖尿病大鼠模型，然后观察其体重、血糖和运动神经传导速度（ＭＮＣＶ）的变化，并以伤害性爪回缩反射和甩尾反射为痛指标测量痛阈。结果表明：腹腔注射ＳＴＺ后，大鼠血糖升高（血糖＞１１．１ｍｍｏｌ／Ｌ），体重增长迟缓，ＭＮＣＶ减慢；实验至第１周时，甩尾反射潜伏期（ＴＦＬ）显著缩短，第２周时，伤害性爪回缩阈值（ＮＰＷＴ）明显降低。上述结果提示，大鼠已产生糖尿病，并处于痛过敏状态。     

基于机会约束条件下舰艇航线动态规划模型研究

从舰艇出航隐蔽性要求出发，根据舰艇在海上不同航段被敌方探测发现的概率不同，建立基于机会约束条件下动态规划航线数学模型，实现从多条航线中选择满足不被探测发现置信水平下的最短航程航线，从而为指挥员迅速选择最优航线提供辅助决策。     

西康铁路增建二线太峪滑坡勘察

太峪滑坡是西康二线控制线路方案的重要工点，在勘察中运用物探、钻探等综合勘探手段，查明了太峪滑坡的特征，进行了滑坡成因分析，评价其稳定性，为地质选线提供了依据。     

现代船舶生活污水处理技术现状与展望

随着海洋环境保护的加强,船舶生活污水的处理要求越来越高。本文主要介绍了现在船舶生活污水处理的现状、存在的主要问题以及一些船舶生活污水的新处理技术的应用和发展趋势。