排序方式: 共有107条查询结果,搜索用时 203 毫秒
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闵国水 《现代城市轨道交通》2013,(5):66-70
根据江苏省沿江城市群城际轨道交通网规划,在深入分析各线客流特征的基础上,结合各线工程条件、技术标准提出了各线独立运营、全部贯通或部分贯通运营等4个方案,并从运能余量、服务水平、客流直达性、运营管理、工程投资等方面对各方案进行了综合比选。 相似文献
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Community-based management (CBM) could be an essential tool to prevent the depletion of marine resources in the Western Indian Ocean region. In Kenya, political pressure to strengthen local governance, has led to adoption of CBM as a way of reducing over-exploitation and managing the competing uses and impacts on the marine environment. Several communities in Kenya have embraced CBM and have set aside or closed previously fished areas to enhance recovery of fisheries and biodiversity. These community fisheries closures (locally called tengefu), despite being degraded, may recover to finfish abundances and biodiversity levels similar to established MPAs or above thresholds for maintaining some ecological services. Communities see their direct involvement and control of these tengefu as more likely to result in benefits flowing directly to them. Community closures are also important for articulating and resolving community values and strengthening their management capacity. Here, we describe the evolution of the tengefu movement in Kenya and combine information from focus group discussions, interviews, underwater surveys and boundary marking to evaluate the current status, opportunities and challenges facing these tengefu. We show that in some cases community closures suffer from slow and incomplete national and local legislative processes, challenges to compliance, and weak management. 相似文献
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冯心宜 《广东交通职业技术学院学报》2008,7(4):4-7
通过设计工作的实践,探讨互通立交平面线形设计的具体步骤、操作方法和注意事项,并对匝道线元参数的取值、线元参数与运行速度的关系、线形设计的连续性与协调性等方面提出了一些见解。 相似文献
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Helene Bareksten Solvang Nikolaos Valantasis-Kanellos Dong-Wook Song 《Maritime Policy and Management》2018,45(4):495-513
This qualitative inductive research explores the potential benefits for the Scandinavian economy and ports through the implementation of the Northern Sea Route (NSR) as an alternative for container shipping to the established Southern route through the Suez Canal. To extract expert’s opinions and address these objectives, we utilised in-depth face-to-face semi-structured interviews through purposive sampling in a single case study setting. The analysis of the data demonstrates that the commercialisation of NSR can yield benefits for the Scandinavian economy (e.g. GDP increase, jobs creation) and reveals the benefits of Scandinavian ports (e.g. ECA’s, flexibility, hinterland, etc.) compared to other ports in North West Europe, which potentially grasp the NSR as an opportunity. However, it is highlighted that this can only be achieved if Scandinavian countries are proactive and secure their involvement. 相似文献
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基于模糊相似度的群决策方案排序 总被引:3,自引:0,他引:3
为解决排序方案多属性特征、决策者对事物认识的局限性以及决策群体中各个体间的矛盾性导致的决策方案排序困难的问题,引入模糊相似度概念,以测度决策专家的偏好差异,用有序加权平均算子集结群体意见,通过与虚拟正、负理想方案比较,实现决策方案排序,并介绍了决策实施步骤. 相似文献
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柴油公交车燃用不同替代燃料的排放特性 总被引:4,自引:0,他引:4
采用OBS-2200车载排放检测系统,分析了柴油公交车实际道路工况的气态排放特性.使用的燃料分别为纯柴油、天然气制油(GTL)与生物柴油,道路工况主要包括市区主干道、次干道和快速路.分析结果表明:公交车燃用各类燃料的CO、HC、NOx和CO2的道路瞬时质量排放率均与瞬态车速变化有良好的跟随特性.公交车燃用各种替代燃料的气态污染物质量排放率随车速增加总体呈上升趋势,其中HC和CO2的质量排放率随车速增大,基本呈线性增加趋势,CO和NOx的质量排放率在中低车速区域随车速上升呈现增加趋势,而在高车速区域有所降低.与主干道、次干道相比,公交车在快速路上燃用各种燃料的气态污染物的排放因子都是最低的.与纯柴油相比,不论是质量排放率还是排放因子,生物柴油和GTL柴油的CO和HC排放都有所下降,且生物柴油的降幅更大一些.从全路况范围来看,纯生物柴油的CO和HC排放最低,纯生物柴油的NOx排放要高于柴油.全路况下,纯天然气制油、体积比为20%天然气制油、体积比为20%生物柴油的CO2排放要低于纯柴油,但纯生物柴油的CO2排放要高一些. 相似文献
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车用代用燃料研究及发展趋势 总被引:3,自引:0,他引:3
较为详细地介绍了车用代用燃料,即液化石油气(LPG)、压缩天然气(CNG)、醇类燃料、生物燃料、二甲醚(DME)、合成柴油、生物柴油、氢能、电能的物理特性、排放、优缺点、水平现状及发展状况。 相似文献
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汶川地震中,位于汶川地震烈度较低区域的西安市大兴路立交发生了较大的破坏。为分析该桥震害原因,采用MIDAS Civil软件建立该桥有限元模型,运用非线性时程方法分析结构的地震响应。分析结果表明:该桥较多滑动支座的支承体系降低了其对主梁变位的约束能力;场地地震动的长周期特性使梁体与支座产生滑移后自振周期延长,导致结构从地震波中吸收了较多能量,加剧了震害。对比2种支承体系修复方案的抗震性能后,推荐支承体系修复方案采用四氟滑板橡胶支座(边墩)、普通板式橡胶支座(中墩)的方案。 相似文献
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为减轻扇区拥挤,科学地利用扇区时隙资源,降低航班延误损失,本文研究了航路资源分配方法,将研究重点放到航路上,并建立了以航班总延误损失最小为目标,以扇区容量为约束的简化数学模型,该模型可以让航空公司灵活、自主地为航班确立优先等级。本文选择航班实际数据进行仿真,并使用优化软件对模型进行求解,算例仿真结果表明,所提方法能够大... 相似文献
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