Ports in Proximity – Competition and Coordination among Adjacent Seaports,edited by Theo Notteboom,Cesar Ducruet,and Peter de Langen

The summer minimum extent of Arctic sea ice shrank drastically in these years, and the opportunity on Arctic international shipping emerged. The Northern Sea Route (NSR), formerly blocked by permanent ice, was completely ice-free in September in the past 3 years. Because this route is much shorter than conventional Asia–Europe shipping lane, many maritime countries have paid attention to exploit the enormous potential of the Arctic Ocean from economical consideration. This study measured the economical advantage of the seasonal NSR by calculating the shipping cost saved.     

不同无机质对球磨脱氯的影响及中间产物的研究

基于提高脱氯效率的目的,向研磨反应中分别掺杂九种不同的无机质,并对脱氯结果进行比较,结果表明,在过量氧化钙的环境中,二氧化硅的加入有利于脱氯反应的进行,并能大大提高脱氯率,远高于其他八种物质;另外,金属碱性的强弱是影响脱氯效果的一个重要因素;水分的加入不利于脱氯反应的进行.对于研磨后样品随研磨时间的变化,本实验也通过XRD,TG,DTG和FTIR等手段进行了表征,观察发现在5 h之后,脱氯率没有明显变化,但大分子有机质仍然会进行反应,生成小分子有机物质.     

基于加权相对熵的二阶马尔可夫模型的进化树重构

利用加权相对熵的二阶马尔可夫模型的基本原理,对DNA序列进行比较.DNA序列由4个字符A、T、C、G构成的序列,将其视为一个马尔可夫链,取状态空间Ι={A,T,C,G},使用二阶转移概率矩阵来描述DNA序列,得到DNA序列的特征值,进而利用特征值定义DNA序列的相似性度量,得到能够对DNA序列进行比较的新方法,并利用这个方法对30个物种的线粒体DNA序列进行分类,通过加权相对熵得到距离矩阵的非比对方法构建的进化树划分更加清晰,准确度更高.     

A nested logit model of mode choice for inland movement of export shipments: A case study of containerised export cargo from India

Predominance of containerised mode of transport for export of general cargo has influenced the mode choices on the inland segment. Prior to containerisation the general cargo for export moved to ports invariably on road in break bulk form. Growth of containerisation led to development of inland terminals enabling an exporter to obtain export clearance at the inland points. This process facilitated an exporter to move cargo either in break bulk or in containerised form, and as inland terminals facilitated aggregation an exporter could move cargo either by road or rail. Thus containerisation increased the inland transport options for an exporter from one to three. The paper develops discrete choice models in the Indian context for inland movement of containerised export cargo. Primary data was collected from 124 export firms through a structured questionnaire. This data is supplemented with data from transport firms and terminal operators. Using the above data, a nested logit model with rail container and road truck in one branch was found to predict the mode choice behaviour best. Amongst the transport attributes, total cost and total transit time were found to be influencing the mode choices significantly. The study however did not find the effect of reliability and loss and damage significant. In addition, the model also predicts that non transport attributes - like the percentage of letters of credit that materialise with inland way bills and the value of export benefits that materialise after export - are important in the mode choice decision.     

高职院校计算机专业与IT培训机构办学模式之比较

近年来,高职院校与IT培训机构在计算机专业教育上都面临着许多困难。本文从招生宣传、教学体系、学生管理、就业指导这四个方面,对高职院校计算机专业与IT培训机构办学模式进行比较。以求为高职院校计算机专业与IT培训机构联合办学找到结合点和突破点。     

基于认知负荷理论的二维教学动画设计

文章阐述了二维教学动画的内涵及其特点,从认知负荷的三种角度分析了影响二维教学动画中的认知负荷影响因素,提出了有效控制二维教学动画的认知负荷的设计原则,并在此基础上进行了案例分析,为二维教学动画的设计提供了参考。     

High-speed rail's potential for the reduction of carbon dioxide emissions from short haul aviation: a longitudinal study of modal substitution from an energy generation and renewable energy perspective

Abstract

This paper quantifies and evaluates, utilising a ‘bottom-up’ approach, the effect on CO₂ emissions of a modal shift from short-haul air travel to high-speed rail (HSR), based on projected passenger movements, between Sydney and Melbourne, Australia during the period 2010–2030. To date, peer-reviewed studies assessing the CO₂ emissions from these competing modes of high-speed transportation have been restricted principally to a cross-sectional assessment, with a Eurocentric bias. This present comparative study seeks to address a gap in the literature by assessing, longitudinally, the CO₂ emissions associated with the proposed operation of HSR against the ‘business-as-usual’ air scenario between Sydney and Melbourne. Under the assumed 50/50 modal shift, and the Australian government's current renewable electricity target, an annual reduction in CO₂ emissions of approximately 14% could be achieved when compared with a ‘business-as-usual’ air scenario. This percentage reduction represents a 62 kt reduction in base year, 2010, and a 114 kt reduction in the final year, 2030. In total, the overall reduction achieved by such a modal shift, under the assumed conditions, during the period 2010–2030, equates to approximately 1.87 Mt of CO₂. Importantly, if the electrical energy supply for HSR operations was further ‘decarbonised’, then it follows that a greater emission reduction would be achieved.     

南充下中坝嘉陵江大桥机制砂钢管混凝土设计试验与研究

以南充市下中坝嘉陵江大桥为依托工程,对利用机制砂配制C60微膨胀混凝土并用于钢管拱肋进行研究。探讨膨胀剂掺量、砂率对混凝土工作性能、力学性能和体积变形性能的影响,研制符合C60机制砂钢管混凝土指标要求的专用减水剂,并对设计混凝土配合比进行优化,以制备满足工程技术要求的拱肋钢管核心混凝土。     

Real-Time Transportation Mode Detection Using Smartphones and Artificial Neural Networks: Performance Comparisons Between Smartphones and Conventional Global Positioning System Sensors

Traditionally, traffic monitoring requires data from traffic cameras, loop detectors, or probe vehicles that are usually operated by dedicated employees. In efforts to reduce the capital and operational costs associated with traffic monitoring, departments of transportation have explored the feasibility of using global positioning system (GPS) data loggers on their probe vehicles that are postprocessed for analyzing the traffic patterns on desired routes. Furthermore, most cell phones are equipped with embedded assisted-GPS (AGPS) chips, and if the mode of transportation the phone is in can be anonymously identified, the phones can be treated as if they are probe vehicles that are voluntarily hovering throughout the city, at minimal additional costs. Emerging cell phones known as “smartphones” are equipped with additional sensors including an accelerometer and magnetometer. The accelerometer can directly measure the acceleration values, as opposed to having acceleration values derived from speed values in conventional GPS sensors. The magnetometer can measure mode-specific electromagnetic levels. Smartphones are subscribed with roadside Internet data plans that can provide an essential platform for real-time traffic monitoring. In this article, neural network-based artificial intelligence is used to identify the mode of transportation by detecting the patterns of distinct physical profile of each mode that consists of speed, acceleration, number of satellites in view, and electromagnetic levels. Results show that newly available values in smartphones improve the mode detection rates when compared with using conventional GPS data loggers. When smartphones are in known orientations, they can provide three-dimensional (3-D) acceleration values that can further improve mode detection accuracies.     

焊后退火工艺对S355J2W钢焊接接头力学性能的影响

通过显微硬度试验、室温冲击试验和冲击试样显微断口形貌分析,对空冷和退火两种处理的S355J2W钢焊接接头进行了性能研究．结果表明：适当的退火工艺可以降低焊接接头的硬度,消除其残余应力,使焊接接头的组织分布更加均匀,提高焊接接头各微区的冲击性能．