新《海安法》下集装箱检验和监管对策研究

介绍了新修订的《海上交通安全法》以及国际公约和其他国内法律法规对集装箱检验和监管的要求,分析了外贸和内贸集装箱检验现状以及监管方面存在的问题,提出了相关对策和建议。     

A coupled numerical approach to simulate the effect of earthquake frequency content on seismic behavior of submarine tunnel

Roughly 90% of all natural vibrations have epicenters in offshore zones and may cause destruction of submarine and floating structures. Such excitations can influence the safe performance of facilities set up on the seabed, like tunnels, jacket legs and subsea oil pipelines. Some researches on this theme have been carried out to demonstrate the importance of seaquake analyses and their effects have been underlined. The present study intends to numerically simulate a two-dimensional fluid-structure interaction (FSI) problem in order to examine the dynamic response of submarine tunnel under real horizontal earthquakes. Pressure is considered as independent nodal variables to represent the fluid flow effects and the induced time-dependent acceleration in porous medium equation is incorporated in the analysis and the tunnel shell is considered as flexible. This work highlights the importance of the input ground motion frequency content that governs the development of the induced seismic stress/strain around the lining of the tunnel. The results demonstrate that for deep sea the increment rate of the circumferential stress caused by surface gravity waves is below 7% when compared to the no-wave interface condition. Moreover, it is confirmed that long-period record may amplify the overall response of the system (up to 60%) specially the lateral and vertical displacements, as well as the principal stress to a lesser extent. The developed numerical model can attend to further analysis of tunnels embedded in a half-space in conjunction with fluid undergoing the severe long-period earthquakes.     

铁路牵引供电系统安全防护与优化技术方案硏究

为了提高铁路牵引供电系统安全防护等级,加强防范强电侵入的能力,减少雷击事故对铁路运输以及设备维护造成的经济损失,本文分析了牵引变电所常见的强电侵入类型及途径,针对现有问题逐一提出了优化技术方案,并阐述了研究思路及方案具体实施方法。     

基于STAR-CCM+的螺旋桨水动力性能分析

文章运用公式将P4119螺旋桨二维坐标型值转换成三维坐标型值,导入Gambit2. 4软件建立几何模型。基于STAR-CCM+软件对该桨进行网格划分,设置边界条件和数值,仿真模拟不同进速系数下的转矩系数、推力系数、敞水效率和桨叶表面压力分布。经与试验值比较,误差均在10%以内,验证了计算结果的准确性,能够满足工程需要。     

福塔纤维沥青混凝土性能研究

福塔纤维（FORTA AR）是一种新型的聚合物有机纤维，它由聚丙烯（Pnlypropylene）和芳纶（Keylar）按照质量比3：1混合而成。对掺加0．045％福塔纤维、0．3％的德兰尼特纤维（Dolanit）以及不加纤维的沥青混合料的高温稳定性、低温抗裂性、以及水稳定性等路用性能进行了研究，结果表明福塔纤维沥青混合料具有优良的路用性能；继而对福塔纤维改善沥青混合料路用性能的机理进行了分析。     

单轴转向架在城轨车辆中的应用前景分析

单轴转向架具有重量轻、曲线通过能力强、低噪声和运行稳定性较差等特点。文章详细分析了单轴转向架的运行性能,并对单轴转向架在城轨车辆中的应用可行性进行了探讨,认为其可满足城轨车辆的运行要求。     

Determination of Critical Slip Surface of Soil Slope

A new complex method is presented considering not only the improvement upon the ＂bad ＂design point, but also the diversity of the newly generated complex, which is obtained by replacing the ＂bad ＂design point with the better design point located at the line between the ＂bad ＂design point and the ceotroid of the remaining design points of the old complex. The new complex method is applied to searching for the critical slip surface of two non-homogeneous soil slopes. The comparison of the results obtained by the new complex method with that by the basic complex method shows that the new complex method is much more likely to find the true critical surface for the randomly generated initial complex.     

铁路桥梁用超细粉煤灰高性能混凝土的试验研究

我国铁路桥梁工程建设中较少掺用粉煤灰,但粉煤灰混凝土在其他工程领域的应用已经证明其具有优良的耐久性能及长期性能。在本文研究中,突破现行规范,从材性试验的角度以30%左右的超细粉煤灰(UFA)等量取代水泥配制了铁路桥梁用的超细粉煤灰高性能混凝土,并对其力学性能、部分长期性能、水化产物以及水泥石形貌等进行了试验研究。试验结果表明,混凝土早期强度主要取决于W/C和UFA掺量,而后期则主要取决于W/B和UFA掺量;通过应力-应变全曲线分析可知,UFA高性能混凝土可采用现行规范设计;混凝土干缩、抗渗、抗裂性能等均优于基准混凝土;同时在微观测试分析基础上,综合考虑施工及养护条件等因素的变异,认为在实际应用中,UFA掺量以不超过30%为宜。     

工程机械柴油机的匹配选择

为选择适应工程机械使用特点的柴油机，对工程机械配套的柴油机选型方式进行了概括分析，着重介绍在柴油机对比选择时的关键性能参数。说明了工程机械用柴油机抗过载能力的特殊要求，总结出通过性能参数和曲线的对比来匹配选择柴油机的方法。