Factors affecting mortality of vertebrates on the roads in the Czech Republic

This paper summarizes the results of monitoring animals killed by vehicles on selected roads in the Czech Republic as well as the circumstances of these accidents. Relationships between species of road-killed animals and factors associated with these accidents were evaluated, such as type of road and traffic density, distance from the built-up area, state of vegetation around the road, terrain topology with regard to the road, and the impact of the month/season.     

船船水动力相互作用的CFD分析研究（英文）

A numerical study of ship-to-ship interaction forces is performed using a commercial CFD code, and the results are compared with experimental data and with the results of a panel method analysis. Two ship models have been used in the interaction forces analysis: a tug and a tanker, advancing parallel to each other with different lateral distances and two different values of the fluid depth. Computations are carried out with four different flow models: inviscid and viscous flow with the free surface modeled as a rigid wall and inviscid and viscous flow with the deformable free surface. A fair agreement was obtained with available experimental data and results obtained by panel method. The influence of viscosity in the computations is found to be comparatively weak, while the wavemaking effects may be important, at small magnitude of the horizontal clearance.     

Contributors to this issue

Contributors to this issue     

对标国际营商环境评价构建城市公交KPI考核体系

立足为优化国际营商环境贡献城市公交之智、发挥城市公交之力,以考核城市公交企业绩效目标为研究视角.本文在国内外研究基础之上,结合现行国家行业规范标准及实地调研结果,对标国际营商环境内涵特征构建城市公交KPI考核体系,并引入熵值法、层次分析法综合计算城市公交KPI考核指标权重,找出公交行业的关键事项或活动,为城市公交发展提供事前预防、事中控制和事后治理的科学决策参考,以提升城市公交运营管理效率和服务质量水平.     

Small Vibrations of Nonlinear Dynamic Systems Containing Non-Rigid Bodies Excited by Stationary Stochastic Processes

From a vibrational point of view, real vehicles form dynamic systems containing non-rigid bodies and nonlinear two-force elements, often excited by stationary random processes. Their theoretical investigation in a broader frequency range is practically possible in the frequency domain only. In the treatment of nonlinearities second-order stochastical linearization methods can be used advantageously. The amount of necessary computations can be vastly reduced by using known receptance matrices of all bodies in the system in its equations of motion after Fourier transformation. The article describes the receptance properties of non-rigid bodies, their use for the determination of the dynamic system's transfer functions and the determination of the output processes' spectral density matrix under stationary random external excitation using stochastical second-order linearization of the nonlinearities.     

The influence of route choice and operating conditions on fuel consumption and CO<Subscript>2</Subscript> emission of ships

The influence of various parameters, such as ship initial speed (full ahead and lower engine loads), loading condition, heading angle and weather conditions on ship fuel consumption and CO₂ emission is presented. A reliable methodology for estimating the attainable ship speed, fuel consumption and CO₂ emission in different sea states is described. The speed loss is calculated by taking into account the engine and propeller performance in actual seas as well as the mass inertia of the ship. The attainable ship speed is obtained as time series. Correlation of speed loss with sea states allows predictions of propulsive performance in actual seas. If the computation is used for weather routing purposes, values for various ship initial speed, loading conditions and heading angles for each realistic sea‐state must be provided. The voluntary speed loss is taken into account. The influence of the ship speed loss on various parameters such as fuel consumption and CO₂ emissions is presented. To illustrate the presented concept, the ship speed and CO₂ emissions in various routes of the Atlantic Ocean are calculated using representative environmental design data for the track of the routes where the ship will sail.     

New routes on old railways: increasing rail’s mode share within the constraints of the existing railway network

This paper describes an integrated methodology for identifying potential ‘quick wins’ for mode shift from road to passenger rail transport. Firstly, a procedure for analysing rail’s relative competitiveness in the market for passenger transport between large urban areas is developed and then applied to a UK case study. The purpose of such analysis is to allow the identification of flows where rail is currently relatively uncompetitive (in terms of journey time in particular) and to assess the reasons for this poor performance, so that the issues which suppress rail use may be addressed. In parallel, a framework, methodology and tool for the assessment of existing and potential capacity (trains, seats, TEUs, etc.) is developed for both passenger and freight traffic, to identify and address network constraints. An illustrative example of the use of these demand and capacity assessment tools is then presented, with the tools used to identify and evaluate flows where rail demand is suppressed by poor service quality and where spare capacity exists which would allow the passenger rail service to be improved without requiring significant investments in infrastructure. The effects of such improvements on demand are predicted, and the cost implications of operating such additional services are discussed. The analysis suggests that there may be significant potential for increasing rail’s mode share by providing additional inter-urban services where rail currently offers an inferior service.     

铜陵公铁两用长江大桥桁片式钢桁梁立体试拼装工艺

铜陵公铁两用长江大桥为五跨连续钢桁梁三索面斜拉桥,钢桁梁采用板桁结合形式,由3片主桁、上层正交异性公路板式桥面、下层正交异性铁路钢箱桥面及横联构成。钢桁梁采用整体焊接式桁片结构,每2个节间的主桁上、下弦杆,斜杆,竖杆通过整体节点焊接成桁片上桥安装。为验证制造工艺和精度并指导实桥施工,选取3．5个连续节间钢桁梁在工厂内一次完成立体试拼装。由于主桁桁片采用水平拼装制作工艺,采用800 t龙门吊机2×200 t吊钩提升加横移对桁片进行90°转体翻身后试拼装。试拼装过程中设置了抗推拉刚性斜撑增强桁片与铁路桥面的稳定性;在斜杆件加垫片,通过调整间隙控制桥梁预拱度。试拼装过程中设置了测量控制网,检测结果满足设计和验收标准,达到了立体试拼装目的。     

智慧治理理念下公交都市创建路径探究——以湛江市为例

"公交都市"是为了缓解小汽车的快速增长和交通拥堵问题所采取的城市交通战略.本文以湛江市为例,分析得出该市公交发展还存在着基础服务水平低、城市建设与公交发展不协调、公交优先战略未真正落实、智慧公交驱动力不足等问题,阻碍着城市与交通体系建设的有序发展.本文将智慧治理理念与公交都市创建在价值层面与技术层面进行结合,并借鉴新加坡与山东青岛的公交都市发展经验,从理念层面、技术层面与智慧管理层面提出适合湛江市公交都市创建的路径,推动城市公交的人性化、智慧化发展.     

国内外公交社区规划研究及经验借鉴

本文通过研究国内外相关文献,对公交社区涵义进行解读和界定,依据国内外公交社区的分类和形式,研究国内外公交社区的发展状况,尤其一些经典的优秀案例,最后总结公交社区规划的三大要素。