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221.
根据洋山港自然、地理条件,运用目前在航道论证方面已经比较成熟的船舶操纵模拟器,有针对性地对大风天气下大型船舶撤离洋山港外航道疏浚段的可行性进行研究;根据所选5250TEU和8000TEU大型集装箱船舶的模拟船型撤离外航道疏浚段模拟试验的结果并基于航迹带概率分布对试验数据充分和系统分析的基础上,提出了大型船舶安全撤离外航道疏浚段的可行性,为洋山港大型集装箱船舶在大风天气下安全撤离外航道疏浚段提供比较科学的参考依据。  相似文献   
222.
马伟斌  王志伟  韩自力 《隧道建设》2020,40(8):1113-1122
阐述长大铁路隧道防灾疏散救援体系,其由土建结构设施、机电设备设施、监控系统、管理系统及疏散模式组成。根据一般地区和高海拔地区防灾疏散救援工程相关研究成果,分析火灾燃烧特性与致灾机制、土建结构设计与优化、机电设备设施优化、监控系统的开发以及应急疏散救援5个方面关键问题或技术的研究、实施现状与存在的问题,提出针对高海拔隧道火灾蔓延与热释放速率、土建参数优化、设备设施适用性检验与耐久性保持、监控系统应用于智能疏散等方面需要进一步开展研究。同时着眼于隧道发展,提出针对特长城市地下区间隧道、深埋地下车站与水下(海底)铁路隧道在上述5个方面亟需开展的研究工作。  相似文献   
223.
The focus of this paper is on the development of a methodology to identify network and demographic characteristics on real transportation networks which may lead to significant problems in evacuation during some extreme event, like a wildfire or hazardous material spill. We present an optimization model, called the critical cluster model, that can be used to identify small areas or neighborhoods which have high ratios of population to exit capacity. Although this model in its simplest form is a nonlinear, constrained optimization problem, a special integer-linear programming equivalent can be formulated. Special contiguity constraints are needed to keep identified clusters spatially connected. We present details on how this model can be solved optimally as well as discuss computational experience for several example transportation networks. We describe how this model can be integrated within a GIS system to produce maps of evacuation risk or vulnerability. This model is now being utilized in several research projects, in Europe and the US.  相似文献   
224.
Large-volume sampling of 234Th was conducted to estimate particulate organic carbon (POC) export in conjunction with drifting sediment trap deployments in the northern Barents Sea in July 2003 and May 2005. 234Th-derived POC fluxes averaged 42.3 ± 39.7 mmol C m− 2 d− 1 in 2003 and 47.1 ± 30.6 mmol C m− 2 d− 1 in 2005. Sediment trap POC fluxes averaged 13.1 ± 8.2 mmol C m− 2 d− 1 in 2003 and 17.3 ± 11.4 mmol C m− 2 d− 1 in 2005, but better reflected the transient bloom conditions that were observed at each station within a season. Although 234Th fluxes agreed within a factor 2 at most stations and depths sampled, sediment trap POC fluxes were lower than large-volume POC flux estimates at almost every station. This may represent an under-collection of POC by the drifting sediment traps or, conversely, an over-collection of POC by the large-volume sampling of 234Th. It is hypothesized that the offset between the two methods is partly due to the presence of the prymnesiophyte Phaeocystis pouchetii, which potentially causes a large variation in > 53-μm POC/234Th ratios. Due to the large proportion of dissolved carbon or mucilage released by P. pouchetii, and because it is thought that P. pouchetii does not contribute significantly to the vertical export of biogenic matter in the Barents Sea, the application of large-volume sampling of 234Th may yield relatively high, and possibly inaccurate POC/234Th ratios. Hence, POC fluxes derived from 234Th sampling may be inappropriate and drifting sediment traps might be a more reliable method to measure the vertical export of biogenic matter in regions that have recurrent P. pouchetii blooms, such as the Barents Sea.  相似文献   
225.
针对连云港后云台山互通式立交设计项目,分析比较了互通的功能和形式,提出了2套适用于山海结合部位复杂地形的全定向Y形互通设计方案,并从技术指标、工程规模和占用土地等方面进行了综合比选,探索了复杂因素控制条件下3路互通立交的设计思路和选型问题.  相似文献   
226.
首次报道了基于全共轭高分子材料聚苯撑苯并二恶唑(PBO)作为空穴传导材料及电子给体,富勒烯(C60)作为电子传输层及电子受体的双层异质结器件.研究发现:该结构器件具有明显的光伏响应特征,开路电压达0.76V,短路电流0.07mA/cm^2;而且在正向偏压下,器件还表现出了较强的激基复合物电致发光现象,在7.1V偏压下,器件的亮度达5.3×10^3cd/m^2,而器件的最高发光效率可达1.8cd/A.该研究表明,基于PBO/C60双层异质结的多功能光电器件具有较好的开发价值和应用前景.  相似文献   
227.
李逊 《交通标准化》2012,(6):120-122
轨道交通车站突发事件下乘客的疏散行为对安全疏散具有重要影响。通过对轨道交通车站乘客疏散的个体行为和群体行为及其产生的影响进行细致分析,结合疏散行为特性和疏散行为的负面影响提出了缓解和解决措施。  相似文献   
228.
通过对城市更新理念、方式的研究,回顾了国外城市道路更新的历程.通过分析我国城市道路更新存在的问题,提出节制、平衡、适度、稳定的城市道路更新的方针.  相似文献   
229.
Five coastal counties in Florida were studied to assess the effect of state-mandated local comprehensive plan policies on hurricane evacuation clearance times and public shelter demand. Numbers of residential units in 2002 and at the time of plan approval were estimated from property parcel data. Abbreviated transportation models were used to calculate 2002 evacuation times and shelter demand and to ascertain the impacts of post-plan residential growth within hurricane hazard areas. Calculated increases in clearance times and shelter demand are not in concert with the state's mandate to maintain or reduce clearance times. State law currently limits the leverage of the state planning agency to compel local governments to implement the required comprehensive plan policies. We recommend a concurrency management strategy that parallels the state's requirement to provide adequate transportation facilities to accommodate the impacts of future residential growth. Such a policy could be employed in other states as well.  相似文献   
230.
臭氧氧化难生化降解有机物的研究   总被引:7,自引:0,他引:7  
采用臭氧氧化法处理难生化降解有机物。以酸性染料、活性染料、分散染料、还原染料模拟有机废水,探讨了臭氧氧化技术处理有机废水的影响因素-pH值、初始浓度、臭氧含量等;研究了臭氧氧化法对难生化降解有机物的氧化效果、生化效果。  相似文献   
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