Carbon and energy footprints of electric delivery trucks: A hybrid multi-regional input-output life cycle assessment

Due to frequent stop-and-go operation and long idling periods when driving in congested urban areas, the electrification of commercial delivery trucks has become an interesting topic nationwide. In this study, environmental impacts of various alternative delivery trucks including battery electric, diesel, diesel-electric hybrid, and compressed natural gas trucks are analyzed. A novel life cycle assessment method, an environmentally-extended multi-region input-output analysis, is utilized to calculate energy and carbon footprints throughout the supply chain of alternative delivery trucks. The uncertainties due to fuel consumption or other key parameter variations in real life, data ranges are taken into consideration using a Monte Carlo simulation. Furthermore, variations in regional electricity mix greenhouse gas emission are also considered to present a region-specific assessment for each vehicle type. According to the analysis results, although the battery electric delivery trucks have zero tailpipe emission, electric trucks are not expected to have lower environmental impacts compared to other alternatives. On average, the electric trucks have slightly more greenhouse emissions and energy consumption than those of other trucks. The regional analysis also indicates that the percentage of cleaner power sources in the electricity mix plays an important role in the life cycle greenhouse gas emission impacts of electric trucks.     

关于铁路路堑边坡区域地质灾害防治的思考

区域地质灾害是铁路工程建设和运营不可避免的工程难题。通过介绍南广铁路梧州段路堑边坡区域地质灾害防治的基本情况、项目地质灾害危险性评估成果以及相关区域地质灾害防治研究现状,分析从区域地质灾害防治角度开展铁路路堑边坡设计的重要性和必要性,提出将区域地质灾害防治贯穿路堑边坡工程整个寿命周期的观点,从设计、施工、运营维护的角度指出区域地质灾害防治的基本思路。     

Low-cost carriers in Asia: Deregulation, regional liberalization and secondary airports

While the demand for low-cost air transportation is potentially huge in Asia, development of low-cost carriers (LCCs) lags behind the region's overall aviation development, and certainly lags behind the LCC development in North America and Europe. It has been noted that market conditions and the regulatory environment of Asia are different from those of North America and Europe. What are the main differences here; and how do these differences impact market entry and success of Asian LCCs? This paper describes salient features of Asian LCCs and their developments. It examines the impact of Asia's domestic and international airline regulations and airport infrastructure on the performance of its LCCs. We find that the “Southwest effect” may also exist in Asia and that the development of low-cost terminals may compensate, at least partly, the scarcity of secondary airports in the region. The experiences of Thailand and China are investigated as case studies.     

基于改进的灰色BP神经网络的区域物流成本预测

区域物流成本的测量与分析是考察一个地区物流水平的关键问题,合理地计算和预测物流成本可以使各级政府对物流发展采取有效的宏观调控措施。本文提出了适合中国地区的物流成本的较合理的测算方法,以吉林省为例进行了实证分析,并采用改进的灰色BP神经网络模型对吉林省的物流成本进行预测,取得了满意的预测结果。研究表明控制物流成本仍然是振兴区域经济,提高经济效益的源泉。     

Tectonically active sediment dispersal system in SW Taiwan margin with emphasis on the Gaoping (Kaoping) Submarine Canyon

The sediment dispersal system in southwestern Taiwan margin consists of two main parts: the subaerial drainage basin and the offshore receiving marine basin. In plan view, this sediment dispersal system can be further divided into five geomorphic units: (1) the Gaoping (formerly spelled Kaoping) River drainage basin, (2) the Gaoping (Kaoping) Shelf, (3) the Gaoping (Kaoping) Slope, (4) the Gaoping (Kaoping) Submarine Canyon and (5) the Manila Trench in the northernmost South China Sea. The Gaoping River drainage basin is a small (3250 km²), tectonically active and overfilled foreland basin, receiving sediments derived from the uprising Central Range of Taiwan with a maximum elevation of 3952 m. The Gaoping Submarine Canyon begins at the mouth of the Gaoping River, crosses the narrow Gaoping Shelf (~ 10 km) and the Gaoping Slope, and finally merges into the northern termination of the Manila Trench over a distance of ~ 260 km. The SW Taiwan margin dispersal system is characterized by a direct river-canyon connection with a narrow shelf and frequent episodic sediment discharge events in the canyon head.In a regional source to sink scheme, the Gaoping River drainage basin is the primary source area, the Gaoping Shelf being the sediment bypass zone and the Gaoping Slope being the temporary sink and the Manila Trench being the ultimate sink of the sediment from the Taiwan orogen. It is inferred from seismic data that the outer shelf and upper slope region can be considered as a line source for mass wasting deposits delivered to the lower Gaoping Slope where small depressions between diapiric ridges are partially filled with sediment or are empty.At present, recurrent hyperpycnal flows during the flood seasons are temporarily depositing sediments mainly derived from the Gaoping River in the head of the Gaoping Submarine Canyon. On the decadal and century timescales, sediments temporarily stored in the upper reach are removed over longer timescales probably by downslope-eroding sediment flows within the canyon. Presently, the Gaoping Submarine Canyon serves as the major conduit for transporting terrestrial sediment from the Taiwan orogen to the marine sink of the Manila Trench. Seismic data indicate that the Gaoping Submarine Canyon has been eroding the Gaoping Slope intensely by presumed hyperpycnal flows and transporting sediments from the canyon head to the middle and lower reaches of the canyon. The middle reach is a sediment bypass zone whereas the lower reach serves as either a temporary sediment sink or a sediment conduit, depending on relative prevalence to deposition or erosion during canyon evolution. Contrast differences in channel gradient and travel length between the Gaoping and Amazon sediment dispersal systems suggest that the Gaoping (Kaoping) River-Canyon system is an active sediment dispersal system for transporting terrestrial materials to the deep sea. The fate of the Gaoping River sediment is the northern Manila Trench.     

尘肺X线胸片的计算机辅助诊断

用模拟和数字两种方法增强图象，以突出病灶，然后运用新颖的区域生长法识别、测量单个尘肺小阴影，通过统计运算进行尘肺病的诊断和分期。此种辅助诊断方法，提供信息直观可靠。３０例Ｘ线胸片密集度测定结果，与矽肺病期级别相一致。     

The role of the air transport service in interregional long-distance students’ mobility in Italy

This study investigates the role of air transport service in the attractiveness of universities to national students, examining how it might stimulate local economic development by attracting highly skilled labor. Examining the flow of Italian university students at the provincial level in 2003–2012, we find that the air transport service affects university attractiveness for long-distance students living at least 300 km from their university. Specifically, accessibility increases with the proximity of universities to airports, when low-cost carriers serve university routes and more alternative airports exist at the origin. Further, our results suggest that, over the last decade, air transport service has facilitated mobility of long-distance students from southern areas to universities in the north of Italy, where students generally move to increase their future prospects.     

区域计算机联锁站间安全通信的实现

阐述了区域联锁站间通信的技术要求，该通信使用的传输设备、传输媒介、通信协议、安全通信网络的拓扑结构等，描述了安全通信在实际区域联锁中的应用。     

基于网络均衡的运输通道客流分配模型

根据各运输方式的经济技术特征,构建了运输通道的时空运营网络来描述各运输方式的竞争性。认为旅客的时间价值(VOT)服从某种分布,旅客的广义出行费用取决于票价和时间两个参数。运用城市交通分配网络均衡思想,提出基于网络的区域运输通道多交通模式客流分配模型,建立了用户最优和系统最优两个目标函数,并给出了模型的求解方法。用一数值示例验证了模型的有效性。     

试析扬泰机场对泰州经济社会发展的影响

文章在分析扬泰机场运营环境和条件的基础上,探究扬泰机场运营对泰州地区经济社会发展的影响,并提出相应的对策建议,具有一定的指导意义。