洋山深水港区一期工程航行安全模拟试验研究

运用电子操纵模拟器 ,预演了第六代集装箱船在各种不利航行条件下进出洋山深水港区的航行过程 ,分析了风、浪、流等环境因素对船舶操纵的影响 ,确定了船舶安全进出港所需的航道宽度、船舶安全靠泊条件和掉头操纵水域尺度。大量的模拟试验研究结果证实 :洋山深水港区具有良好的船舶航行条件 ,船舶按一期工程小洋山方案 (一 )、小洋山方案 (二 )以及小洋山～镬盖塘方案进行靠离泊和掉头操纵无本质差异 ,主要不同点在于船舶通过窄口后小洋山方案 (一 )和小洋山方案 (二 )比小洋山～镬盖塘方案有较长的制动水域     

Organic carbon budget for the Gulf of Bothnia

We calculated input of organic carbon to the unproductive, brackish water basin of the Gulf of Bothnia from rivers, point sources and the atmosphere. We also calculated the net exchange of organic carbon between the Gulf of Bothnia and the adjacent marine system, the Baltic Proper. We compared the input with sinks for organic carbon; permanent incorporation in sediments and mineralization and subsequent evasion of CO₂ to the atmosphere. The major fluxes were riverine input (1500 Gg C year^− 1), exchange with the Baltic Proper (depending on which of several possible DOC concentration differences between the basins that was used in the calculation, the flux varied between an outflow of 466 and an input of 950 Gg C year^− 1), sediment burial (1100 Gg C year^− 1) and evasion to the atmosphere (3610 Gg C year^− 1). The largest single net flux was the emission of CO₂ to the atmosphere, mainly caused by bacterial mineralization of organic carbon. Input and output did not match in our budget which we ascribe uncertainties in the calculation of the exchange of organic carbon between the Gulf of Bothnia and the Baltic Proper, and the fact that CO₂ emission, which in our calculation represented 1 year (2002) may have been overestimated in comparison with long-term means. We conclude that net heterotrophy of the Gulf of Bothnia was due to input of organic carbon from both the catchment and from the Baltic Proper and that the future degree of net heterotrophy will be sensible to both catchment export of organic carbon and to the ongoing eutrophication of the Baltic Proper.     

Managing transportation during highway reconstruction: A recommended process

Major highway reconstruction can cause significant disruptions to existing travel patterns and economic activity. Reducing these impacts on travelers, shippers, businesses and residents requires that innovative and effective transportation management actions be developed and implemented. This paper reports the major findings and recommendations of a research study on managing transportation during highway, reconstruction. The primary objectives of the study were

大风低温高对流区超高墩0号梁段施工托架设计

针对大沙沟特大桥处于大风区、低温高对流区施工条件下对超高墩(高达106 m)0号梁段施工托架的设计进行研究分析,确保大沙沟特大桥在复杂施工条件下托架施工的安全性及解决0号梁段施工质量等诸项技术难题。     

南京大胜关长江大桥CPⅢ点位随温度变化的模型研究

以京沪高铁南京大胜关长江大桥CPⅢ高精密测量为工程背景,经过坐标变换后计算得出各个点位的膨胀值,利用概率与统计理论分析处理,得到可用于建模的点对数据(ΔS,ΔT)。根据一定的假设条件,建立了测量点位的位移随环境温度变化的线性回归模型,从而得出大桥CPⅢ位置POS与温度T之间的关系。利用该模型修正并评价测量数据,结果表明其较差完全符合要求,区间预测模型可用。并编程实现了CPⅢ点位位置随环境温度变化的自动化预测,能够方便地为大桥的变形观测、定期复测和实际胀缩效果分析提供一定的参考。     

论轨道交通对珠三角区域经济一体化的促进作用

珠三角区域城市群的崛起扩大了区域内交通需求规模,改变了交通需求结构,需要尽快形成以轨道交通网为骨干的区域快速公交走廊。阐述了轨道交通的建设与发展对区域经济一体化发展具有的经济诱发、开发先导、区位再造和资源创造等四大功能。提出了加强规划协调、创新发展理念、优化体制机制和给予政策支持等四方面的措施建议,以充分发挥轨道交通对珠三角区域经济一体化的促进作用。     

高原富水区域连通河沟段隧道综合施工技术

详细介绍了关角隧道4号斜井施工过程中,穿越与地表河谷连通性密切地段的综合处理技术,其中包括连通试验测定,地表处理等措施。施工实践表明,所介绍的施工方案合理可行,效果较好,经济效益显著。     

沙特南北铁路沙漠路基设计与施工技术

沙特南北铁路有近200 km的线路穿越沙漠地段,风积沙是沙漠段沿线最普遍的材料。介绍了该项目针对沙漠路基进行科学、合理缓解风沙影响和充分利用风积沙作为路基填料的施工图特别设计,通过材料控制、施工工艺试验、施工过程控制和质量检验等手段,保证沙漠路基施工质量的具体方法和取得的良好效果。对沙漠路基工程有效利用风积沙具有深远意义。     

基于节点重要度交通区位布局法的城市群公路网布局研究

在城市群公路网布局研究中,为了加强交通基础设施建设,促进人、物、资金合理流通,加快城市群的协调发展,针对城市群公路网的区位特性,运用交通区位理论,建立了基于遗传算法的公路网布局双层规划模型,提出了节点重要度法与交通区位线法融为一体的城市群公路网规划布局新方法。该方法对于进行城市群公路网的合理布局,推动区域经济社会快速健康协调发展具有一定现实意义。     

一种车牌定位算法的实现

车辆牌照的自动识别是智能交通系统中的一项重要技术,而车辆牌照的定位又是车牌识别的关键点之一。文章依据二值化图像中车牌区域跳变频率高的事实,提出一种算法来确定车辆牌照在原始图像中的水平位置和垂直位置,从而定位车辆牌照。实验结果表明本算法处理速度较快、便于实现。