常规货船直升机作业区设计和布置要求

根据航运船舶直升机作业区的相关规范、规则,阐述了常规货船直升机操作的分类、直升机作业区的布置位置、直升机作业区的具体要求。此外,还介绍了直升机作业区域内风速及风向的指示、脱险通道、排水设施、障碍物限制、通信信号设施、照明灯光设施、消防设备等其他方面的要求。     

2000吨级斯特林发动机AIP潜艇方案论证研究

对采用斯特林发动机作为主动力装置的2000 t级排水量非核动力潜艇进行了方案论证研究,给出了潜艇动力装置功率、最大水下航速、经济航速、低噪声航速、水下不间断续航力、自持力等主要技战术性能指标,提出了不同的斯特林发动机动力装置方案并进行了比较。研究表明,2000 t级排水量非核动力潜艇采用斯特林发动机作为主动力装置,其主要技战术性能指标均超过现役非核动力潜艇。     

Excel在沥青路面厚度检测数据分析中的应用

与钻孔取心和挖检相比,地质雷达检测是一种能够连续采样的路面厚度无损检测手段。但是,需要对大量的试验数据进行统计分析,人工处理费时,且容易出错。因此,以电子表格＂Ex-cel＂自编程序,统计分析路面厚度的平均值、标准差、代表值、变异系数等,探讨了一种路面厚度检测数据处理的有效途径。     

非航海毕业生海员培训需注意的几个问题

文中通过对辽宁海事局辖区非航海毕业生海员培训情况统计,根据非航海毕业生海员培训适任评估和考试结果,系统分析了非航海毕业生培训中存在的问题,并有针对性地提出了相关建议。     

首都道路交通管理信息化应用成果综述

从近年来北京市公安交通管理信息化应用现状出发,对北京市道路交通管理信息化建设工作进行了全面、深入的调查研究,总结归纳了近年来全市道路交通管理在挖潜科技系统效能、构建信息化应用体系、提升路面交通管理水平所取得的成绩,并对未来信息化建设的发展完善进行了展望。     

Has the transport-led economic growth effect reached a peak in China? A panel threshold regression approach

Using China’s province-level panel data from 1987 to 2010, this study explores the optimal level of transport infrastructure accumulation maximizing the growth rate. We investigate under what circumstances can additional transportation infrastructure capacity positively affect economic growth, based on panel threshold regression models. Our empirical findings suggest that there is a non-monotonic relationship between the stock of transport infrastructure and the long-run growth rate. The magnitude of transport-led economic growth effect significantly depends on the level of the existing transport network. The empirical results identify two endogenous cut-off points of efficiency of transport-led economic growth effect. When the highway network density is lower than 0.17 km/km², an insignificant positive relationship between highway infrastructure accumulation and economic growth was found. When the highway density is estimated between 0.17 and 0.38 km/km² or higher than 0.38 km/km², expanding the highway network has a significant positive effect on economic growth, but the magnitude of the impact is weaker in the latter, with the estimated coefficients equal to 0.23 and 0.09 respectively. Although China still enjoys a positive economic growth effect led by building more large-scale highway infrastructure, the magnitude of the effects of most provinces in China has already passed the saturation point and continuously expanding the highway network is not very productive.     

海洋救助拖船救助功能与配置研究

海洋救助拖船是对海上遇险人员和船舶实施有效救助的专用船舶.为对接我国海洋战略发展需求,要适应在深远海大风浪恶劣海况条件下对海上遇险人员和船舶的有效救助.针对海洋救助拖船适应深远海救助需求的基本功能设置,就船舶救助和人命救生的拖曳救助作业、对外消防灭火、海面人命救生、海面搜救、获救人员救治及保障等主要设备及设施配置作技术探讨.     

Are there bubbles in the shipping freight market?

ABSTRACT

This paper addresses the reconsideration of price bubbles specific to the shipping freight market based on the method of the Generalized Supremum Augmented Dickey–Fuller (GSADF). This approach offers the opportunity to recognize multiple bubbles and set their corresponding original and final dates. Empirical results reveal that four bubbles existed in the shipping freight market between October 1988 and February 2018 in which freight deviated from fundamental values. Strong demand (especially in China), the supply capacity, crude oil prices and U.S. dollar fluctuations are potential explanations for the first three bubbles. The global financial crisis that burst in 2008 is the major factor results in the last bubble. Hence, we must distinguish the potential reasons of bubbles in different periods and take measures such as promoting economic multipolarization, strengthening the bargaining power of China, building an effective information transfer system, employing financial derivatives and accelerating the consolidation of the shipping industry to alleviate the negative influences on global seaborne trade.     

城市轨道交通换乘站运行效率评价

通过对城市轨道交通换乘系统的分析,分别从基础设施、运营、信息化等方面选取具有代表性的指标,建立了城市轨道交通换乘站运行效率评价指标体系;结合灰色系统理论,建立了基于综合灰色关联度加权法的城市轨道交通换乘站运行效率评价模型;以重庆轨道交通的换乘站为例,计算了换乘车站的多项指标并排序,得到评价结果。结果表明:该评价模型具有可操作性和实用性。     

激光焊接技术在车身高强钢小焊缝焊接中的应用

高强钢将是未来应用最为广泛的钢材种类,尤其在汽车领域,对汽车的安全起着重要的作用,而焊接工艺直接影响到整车的碰撞能力,以及减重降耗。激光在车身高强钢焊接中,线能量密度高度集中、热影响区小,并且激光束具有可以在大气中焊接的优点,既可以对大型高强钢构件作深度熔焊,又可以进行微型精密焊接。文中通过试验研究激光在车身高强钢小焊缝情况下焊接速度与焊缝深度以及焊缝宽度的关系。