能效设计指数EEDI功率曲线的直接计算方法

船舶能效规则强制生效后，所有适用船舶必须满足Attained EEDI≤Requied EEDI的条件，因此准确估算或预报功率曲线从而计算得到Attained EEDI将对适用船型具有极为重要的意义。根据国内外关于功率-转速-航速预报的最新进展，依据螺旋桨敞水性能图谱，采用KT/J^2系数，给出了功率曲线的直接计算方法，经实际算例验证，该方法相对传统的间接计算方法更为清晰简便，且结果准确可靠。     

通信网络运维保障转变研究

通过多个方面对通信企业通信网络运维保障发展转变进行研究,对通信网络运维保障转变进行分析和总结,并从中寻找未来通信网络运维保障的发展趋势。     

施工作业对沥青混凝土路面质量的影响及对策

结合实践,分析沥青混凝土路面摊铺中易出现波浪、离析等缺陷的原因,提出相应的防治对策,对提高路面施工质量和作业水平,具有一定的指导作用。     

寒冷地区公路隧道节能照明设计

鉴于快速发展的公路隧道在设计及运营管理过程中暴露出的许多不足,如由于我国照明设计规范中的设计照明参数值较大,公路隧道照明耗电负荷大于90 k W/km,高耗电现象较多,故导致很多隧道运营时往往只使用设计照明负荷的1/2或1/3,甚至很多低等级公路隧道干脆不开照明灯,给隧道运营带来了安全隐患。文章就完善公路隧道节能照明设计展开分析,力求对公路隧道节能照明设计提供借鉴。     

一种摆式列车未平衡加速度测量仪的研究

介绍了一在于单摆的高精度数字测量仪，采用磁电涡流阻尼和光电编码器摆角的结构，它适合于测量车体的理论与实际倾斜角的误差，从而测量对应的未平衡加速度。对测量原理进行了分析，同时介绍了实验室条件下试验的结果。     

Mitigating the effect of impact loading on a vehicle using an essentially nonlinear absorber

The aim of this study is to investigate the ability of an essentially nonlinear vibration absorber to mitigate the large accelerations transmitted to a passenger compartment of a vehicle which is subjected to shock-type transient loading at the chassis. For such problems, the induced vibration typically attains its maximum value shortly after the application of the loading; thus, it may be impossible to dissipate a major portion of the input energy prior to the occurrence of the peak response. Here, a class of absorbers possessing a form of discontinuous essential stiffness nonlinearity is employed to achieve the desired mitigation. In this paper, we apply a single vibro-impact (VI) absorber to the chassis and examine whether the resulting energy transfer mechanism is an effective way to reduce the peak value of the inertial force measured at the passenger compartment. The influence of the absorber parameters is first studied based on a practical impulsive force, and the optimal design of the absorber is then obtained. Next, an asymmetric clearance arrangement of the absorber is suggested to facilitate the mitigation. Finally, an impulsive acceleration excitation is applied to the system to examine the robustness and efficacy of the optimised absorber. Results of numerical simulations demonstrate that a properly designed VI absorber can significantly decrease the maximum inertial force at the passenger compartment, generated by external impulsive excitations.     

Comparing rail fuel efficiency with truck and waterway

This paper presents a railroad energy efficiency model used to estimate the fuel economies for classes of trains transporting various commodities. Comparable procedures are used to estimate truck and waterway fuel consumption. The results show that coal unit trains are 4.5–5.0 times more energy efficient than movements in the largest trucks allowed in the eastern and western regions of the US, unit grain train movements in the central US are 4.6 times more fuel efficient, soda ash unit train and non-unit train shipments are 4.9 and 3.2 times more efficient, and ethanol unit train and non-unit train movements are 4.8 and 3.0 times more efficient. In terms of barge traffic, coal unit train and non-unit train are 1.3 and 0.9 times as energy efficient in the eastern US, grain unit train and non-unit train movements are 1.7 and 1.0 times more efficient from Minneapolis to the Gulf of Mexico, and grain unit train and non-unit train movements are 1.0 and 0.7 times more fuel efficient from the Upper Ohio River to the Gulf of Mexico.     

基于卷积型小波包变换的船用水位调节器故障辨识

以某型蒸汽船的主冷凝器水位调节器为研究对象,应用卷积型小波包变换提取各种故障信号分解后的相对小波包能量,建立水位调节器标准故障库,并引进Euclidean空间距离公式作为判据进行故障识别。实验结果表明,该方法可以对水位调节器的典型故障进行快速、正确分类,降低了其故障定位与维修的盲目性。     

论高速公路区域经济综合开发

高速公路与区域经济存在着相互依存、相互促进的辩证关系。将高速公路投资经营与区域经济相结合,可以实现高速公路区域经济一体化协调发展。     

造船企业的经营风险及防范措施

由于金融风暴的影响，造船行业进入了下行通道，造船企业很有必要正视潜在的风险，探索应对措施。本文对造船企业的合同风险、市场风险、汇率风险进行了初步分析，并提出了相应的防范措施。