Do changes in the residential location lead to changes in travel attitudes? A structural equation modeling approach

Transportation - Numerous studies have found that travel attitudes might not only affect travel behavior, but also the residential location choice as people might choose a residential location...     

高大建筑空间采暖方式的分析

从传热机理出发，对高大建筑空间的采暖方式进行分析，指出各种采暖方式的优缺点，并着重介绍了横向热风幕分层采暖方式的数值模拟和现场实测结果，说明在高大厂房中采用该采暖方式可获得较高的热舒适性。     

低流量下蒸汽发生器倒U型管内流动传热的数值模拟

针对自然循环工况下蒸汽发生器部分倒U型传热管存在倒流现象,利用CFD软件对倒U型传热管内单相水流动传热特性进行研究。通过建立不同管长的倒U型管水动力曲线,分析了管长对倒流的影响,得出长管处易发生倒流的结论;通过对长管重位压降和摩擦压降随雷诺数变化情况进行分析,对倒流现象的出现进行了的理论解释。该文所得结果对倒流管空间分布的研究具有一定的意义。     

Bottom slamming on heaving point absorber wave energy devices

Oscillating point absorber buoys may rise out of the water and be subjected to bottom slamming upon re-entering the water. Numerical simulations are performed to estimate the power absorption, the impact velocities and the corresponding slamming forces for various slamming constraints. Three buoy shapes are considered: a hemisphere and two conical shapes with deadrise angles of 30° and 45°, with a waterline diameter of 5 m. The simulations indicate that the risk of rising out of the water is largely dependent on the buoy draft and sea state. Although associated with power losses, emergence occurrence probabilities can be significantly reduced by adapting the control parameters. The magnitude of the slamming load is severely influenced by the buoy shape. The ratio between the peak impact load on the hemisphere and that on the 45° cone is approximately 2, whereas the power absorption is only 4–8% higher for the 45° cone. This work illustrates the need to include slamming considerations aside from power absorption criteria in the buoy shape design process and the control strategy.     

Advances in port studies: the contribution of 40 years Maritime Policy & Management

Port economics, management and policy have progressively emerged as a distinctive research field, and a core part of maritime economics. This paper provides an analysis of all the 267 port studies published in Maritime Policy & Management (MPM) since its inception in 1973. This paper provides a content analysis for seven interrelated research theme categories including main research topics and methods, authorship distribution and citation counts. It is demonstrated that MPM played, and continues to play, a key role in publishing research on seaports. The published research increasingly applies established analytical frameworks to ports. The paper concludes with a discussion on current challenges for port-related research.     

Value creation in the port: opening the boundaries to the market

In the era of fierce competition among ports as elements of value chain systems, the opening of the boundaries to the market represents a crucial challenge that port authority has to cope with, in order to guarantee a lasting economic and social development of the port and its hinterland. We propose a theoretical framework to analyse value creation in the port and its hinterland through two core concepts: resource allocation and interaction. We illustrate such framework with the case of the port of Naples and, specifically, the contribution of the port authority and other port business operators to the value creation process of Garofalo, an export-oriented firm located in its hinterland. A discussion and suggestions for future research are provided in the last section.     

Au40 Pd20合金原子团簇惰性气体氛围凝聚动力学行为研究

采用蒙特卡洛方法,结合Tight-binding和Lennard-Jones作用势,对Ar原子氛围中初始随机分布的40个Au原子和20个Pd原子体系的凝聚动力学行为进行了研究．Ar原子氛围对合金团簇的形成过程及其形貌尺寸有重要影响,计算表明：不同的Ar原子氛围得到的Au40 Pd20合金原子团簇凝聚结构形貌不同;在降温退火过程中, Ar原子密度大时,得到的Au40 Pd20合金原子团簇结构更加紧凑,且Au40 Pd20合金团簇凝聚相变温度更高;而恒温退火过程中,则发现较高温度时能得到较为紧凑的合金团簇结构,Ar原子密度越大,系统到达平衡的动力学时间更短．模拟结果能为惰性气体冷凝方法中实现合金团簇结构与形貌可控制备提供参考．     

Wave Scattering by Porous Bottom Undulation in a Two Layered Channel

The scattering of plane surface waves by bottom undulations in channel flow consisting of two layers is investigated by assuming that the bed of the channel is composed of porous material. The upper surface of the fluid is bounded by a rigid lid and the channel is unbounded in the horizontal directions. There exists only one wave mode corresponding to an internal wave. For small undulations, a simplified perturbation analysis is used to obtain first order reflection and transmission coefficients in terms of integrals involving the shape function describing the bottom. For sinusoidal bottom undulations and exponentially decaying bottom topography, the first order coefficients are computed. In the case of sinusoidal bottom the first order transmission coefficient is found to vanish identically. The numerical results are depicted graphically in a number of figures.     

蓝牙协议一致性测试技术的研究

蓝牙协议一致性测试不仅可以验证一个开发商开发的蓝牙协议是否符合蓝牙特别兴趣小组规范的一种协议一致性测试,它还可以验证一个蓝牙协议实现的能力和行为.主要介绍蓝牙体系结构,并以服务发现协议(SDP)为例,对蓝牙协议一致性测试提出一套解决方案,便于蓝牙测试仪以及自动化测试工具的实现.     

蓝牙耳机系统及其实现

介绍蓝牙及其协议栈体系结构;讨论了蓝牙耳机的基本概念及其应用模型,最后详细阐述了该蓝牙耳机系统的设计和具体实现.