武汉：13个BT项目总投资405．9亿

近日，武汉市政府召开“武汉市城区交通项目BT融资推介会”，面向“中”字头公司和本市大型建设企业推出了13个重大项目，总投资405．9亿元，都是一两年内要启动的项目。这批重大项目涉及城市交通骨架网、过江通道、地铁和连通城市圈的道路。分别是：鹦鹉洲过江通道、二环线汉口段、江北快速通道、二七长江大桥两岸接线道路、三环线最后9．6公里——东段、     

常泰过江通道桥梁与隧道方案综合比选

常泰过江通道直接联系江苏常州新北区与泰兴市，是《江苏省高速公路网规划（2017-2035）》中15座高速公路过江通道之一，也是《长江经济带立体综合交通走廊规划（2014-2020）》中江苏省14条过江通道之一。项目从国家规划、公路及铁路过江需求、节约过江通道资源等因素出发推荐采用公铁合建形式过江；在跨越长江的位置选择中，推荐从宏锦物流码头上游、录安洲边防站与魏村水厂之间穿过的D过江线位。文章以此为基础，对推荐的D过江线位桥梁方案和隧道方案进行深入研究。经过论证比较，隧道方案在通航、防洪、环保、特殊天气应对方面略有优势；但桥梁方案在功能、运营安全、防灾救援、管养与成本方面桥梁方案优于隧道方案。且由于合建的多功能桥梁方案在过江资源占用上实现了1+1+1<3的集约、节约目标，因此最终推荐多功能合一的桥梁过江方案。     

固原市清水河城区段河道蓄水工程联合运行调度方案研究

固原市规划在清水河城区段河道内建设橡胶坝拦蓄河道径流,形成城市水面,达到改善城市环境的目的。清水河城区段在三里铺桥～火车站桥段4.67km河道内建设橡胶坝蓄水工程6座。清水河汛期洪水峰高流急,来水含沙量较大,如此运行条件,做好6座橡胶坝的联合运行调度、科学运行管理是发挥工程效益和保证工程安全的关键。因此,针对本工程特点,对工程运行各方面进行研究,编制了固原市清水河城区段河道蓄水工程联合运行调度方案。     

CFG桩+泡沫混凝土解决软基桥头跳车的联合应用研究

为了减小路桥过渡段的差异沉降,缓解软土地区的桥头跳车问题,提出了一种采用CFG桩复合地基联合换填泡沫混凝土加固软基的方案。依托实际工程案例,采用有限元软件MIDAS GTS/NX建立了CFG桩复合地基工况模型与原始工况模型,检验了CFG桩复合地基的有效性,然后建立了CFG 桩联合台后换填泡沫混凝土方案的模型进行固结沉降分析,并验证了两者联合应用的优越性。研究结果显示：1）CFG桩复合地基对于软基的加固效果显著,其工期沉降比原始工况减少了18.32 cm;2）CFG桩复合地基加固软基时,台后换填泡沫混凝土使桥台与路面的台阶型差异沉降相较于台后普通路基填土工况减小了0.72 cm,对于桥头跳车问题的治理效果良好;3）模拟结果与工程实测沉降数据对比误差极小,说明了有限元模拟的可靠性。研究结果有效解决了常见的桥头跳车问题,方案具有更安全、环保、可靠的特点,可为软土地区的路桥过渡段工程提供一定的理论参考与借鉴。     

调度自动化系统数据传输通道的比较和选择

变电站实现无人值班以来,调度自动化系统已经成为电网安全稳定运行的不可缺少的技术支持手段,电网运行数据质量的好坏直接关系着电网分析的可靠性,而数据传输通道承载着电力数据的传输,它的优劣影响着数据质量的好坏,下面分别介绍了电力系统中三种常见的传输通道,它们有不同的适用环境,经过多年的发展,网络传输通道是未来发展的方向。     

城市规模、城市结构、产业集聚度与城市能耗

能源是城市经济发展的基础资源,在城市化的进程中,城市的人口、产业、交通、建筑等各要素决定了城市能耗的高低,它们共同形成了不同的城市规模、结构,以及产业结构。本文利用全局主成分析法与固定效应模型,分析发现我国城市发展进程中,东、中、西部城市的规模、结构、产业集聚度的差异所引致的城市能源消耗增长率完全不同。为提高能源利用效率,东部地区应继续发挥产业集聚效应和技术优势,并大力提高城市交通运行效率。同时,中部地区应加快产业结构调整和升级,加强城市用地的合理规划。西部地区则应提高城市密度,改善大而散的城市结构。     

城市规模、城市结构、产业集聚度与城市能耗

能源是城市经济发展的基础资源,在城市化的进程中,城市的人口、产业、交通、建筑等各要素决定了城市能耗的高低,它们共同形成了不同的城市规模、结构,以及产业结构。本文利用全局主成分析法与固定效应模型,分析发现我国城市发展进程中,东、中、西部城市的规模、结构、产业集聚度的差异所引致的城市能源消耗增长率完全不同。为提高能源利用效率,东部地区应继续发挥产业集聚效应和技术优势,并大力提高城市交通运行效率。同时,中部地区应加快产业结构调整和升级,加强城市用地的合理规划。西部地区则应提高城市密度,改善大而散的城市结构。     

基于云计算的城市轨道交通信息化平台研究

随着云计算技术的成熟,城市轨道交通智能化已经成为其未来发展的重要方向。探究云计算与城市轨道交通运营的融合路径,研究城市轨道交通云计算平台的基础架构,特别关注了其计算资源架构,并从知识库和运行大数据分析两个角度为其灾备中心应急处置系统提供了两种故障处理思路,最后对于大型城市中心云计算模式的缺陷提供了边缘云计算思路,为城市轨道交通智能化发展提供借鉴与参考。     

以“供电服务指数”提升客户用电感知

国网四川电力资阳市雁江供电分公司以“供电服务指数”应用为抓手,围绕客户用电感知,充分挖掘数据价值,对供电服务全过程进行精准评价,取得了客户用电感知持续提升、内外部数据有效关联、供用电关系从“供应”转为“共赢”的管理成效。国网四川省电力公司资阳市雁江供电分公司(以下简称“雁江供电公司”)围绕客户用电感知,充分挖掘数据价值,对供电服务全过程进行精准评价,构建风险发现和整改提升实时触发、服务前端和指挥中心纵向畅通、营销服务和运行维护横向协同的客户用电感知生态闭环机制,使供电服务工作有明确目标和内生动力,推动供电服务能力和供电可靠性提高。     

地铁工程施工中的成本管理与控制

随着我国经济的蓬勃发展和城镇化速度加快,作为重要基础设施项目,大中城市的地铁交通建设迎来了新一轮发展机遇。但由于地铁工程规模大、技术复杂,施工建设工期长、风险高等因素,导致地铁工程项目造价长期居高不下,而二级城市往往建设经费有限、设计概算较低,在一定程度上制约着地铁交通的发展。因此,加强地铁工程成本控制,降低工程造价,已经成为我国城市地铁建设面临的主要问题。本文基于施工过程中的社会效益和可持续发展角度,探讨建筑企业在地铁施工过程中如何控制工程项目成本,通过分析影响地铁施工过程项目成本要素,寻找地铁工程项目施工过程成本管理与控制的有效途径。     

京津冀地区主要城市集聚差异研究

本文依据相关理论构建城市集聚测度模型,对京津冀地区主要城市的集聚度进行了测算,并使用传统差异系数研究了京津冀地区内部主要城市间的集聚差异,利用区域特定差异指数判断了京津冀地区空间差异的方向,通过多元回归模型对城市集聚影响要素进行了实证分析。研究结论为：京津冀地区主要城市近10年来的城市集聚程度总体上呈增长趋势,城市间集聚程 度差异明显;中心城市与中心城市外围地区的差异增大,沿海城市与内陆城市差异不明显;出口贸易、固定资产投资及第三产业对城市集聚水平影响显著,是影响城市集聚的重要因素,也是导致城市间集聚加剧的重要直接驱动力。     

Urban food policies in German city regions: An overview of key players and policy instruments

Although food is an emerging topic on municipal policy and planning agendas, a systematic examination of policy development, its implementation and the instruments used at the urban level is lacking. This study was carried out with the aim of gaining new insights into the prevalence of certain food policy instruments and capacity of policy action. In order to do so, we developed an analytical framework to investigate urban policy and planning approaches related to food issues and applied it in ten large German cities. First, we identified different actor groups and analysed their role in urban food policy (level of involvement in municipal food projects). We then studied the variety of policy and planning instruments and their application for different elements in the food system. For the empirical study, we employed a case study approach and utilised data gathering methods of qualitative research, i.e. expert interviews and document analysis. Our empirical findings in the studied cities reveal that urban food policy activities are still very fragmented and often based on individual initiatives within the administration. Integrated urban food policies and their implementation through urban food strategies are still an exception in major cities in Germany. We found that municipal actors follow mainly sectoral approaches, using a wide array of steering instruments, i.e. informational instruments and public procurement policies. However, their capacities for policy implementation remain limited due to missing financial and staffing resources. Accordingly, the potential the urban food system offers for sustainable development through multifunctionality and sectoral integration, is still underexploited.The systematic approach developed in this study may contribute to a better understanding of different policy approaches taken. The applied typology of policy instruments might also be useful for identifying effective ways to implement urban food strategies, to understand mismatches between instruments and different policy domains, levels and administrative units, e.g. at the urban-rural interface, and to design of new policy instruments.     

Urban crowdsourcing: Stakeholder selection and dynamic knowledge flows in high and low complexity projects

Urban crowdsourcing is a new form of open innovation that aims to develop smart cities. Due to the heterogeneity of partners in urban planning, knowing the type of knowledge gained from each stakeholder at each stage of the crowdsourcing process needs to be understood for effective collaborations and innovative knowledge flow activation. Using a qualitative approach with experts involved in the Casablanca Smart City project, this research investigates complex multi-stakeholder ecosystems. More specifically, this study identifies and examines the role of external stakeholders at each stage of the innovation process, and the resulting dynamic knowledge flows that help improve the process of urban crowdsourcing in the development of smart city solutions. Depending on the complexity of the innovation project, findings identify three primary stakeholders (citizens, public authorities, and private and public firms) and three secondary stakeholders (NGOs, universities, consulting companies). Results show at which of the four steps of urban crowdsourcing they intervene. Furthermore, the findings reveal a dynamic learning environment composed of two knowledge flows (“learning with” and “learning from” stakeholders).     

液力透平增压泵轴向力数值计算与分析

针对用于合成氨脱碳工艺流程的余压能量回收液力透平增压泵的推力轴承设计缺乏数据支撑的问题,采用全流场数值模拟方法,得到了透平增压泵泵侧和透平侧的外特性及其总效率曲线,并给出了两侧中间面、叶片表面和轴向中间面压力分布情况,进而分析了两侧盖板力、叶片力和内表面力及透平增压泵总轴向力变化趋势。结果表明,泵侧轴向力随着流量的增大先减小后增大,透平侧轴向力则逐渐增大;在工况范围内,总轴向力的方向始终指向泵侧,与理论计算得到的趋势一致。研究结果验证了液力透平增压泵只需在透平侧安装推力轴承的可行性,可为液力透平增压泵的推力轴承结构设计提供轴向力数据参考。     

Conceptualizing digital and physical connectivity: The position of European cities in Internet backbone and air traffic flows

‘Digital’ telecommunication flows and ‘physical’ corporeal flows provide researchers with comprehensive indicators of the economic interactions between cities. However, previous research drawing on telecommunication-based measures of inter-urban connectivity has been hampered by inadequate conceptualizations and data. This paper draws on this observation to devise a new approach for measuring inter-urban connectivity based on a city’s insertion in Internet backbone networks. The straightforward example of air transport flows is thereby used to outline this approach. To investigate telecommunication and air passenger flows, use is made of European statistics on Internet eXchange Points and the MIDT airline database respectively. The approach is illustrated through a systematic comparison of the position of European cities in both types of networks. It is found that European cities assume largely similar hierarchical levels in terms of digital and physical information flows, albeit that the digital connectivity of centrally located European cities is often somewhat higher than that of peripheral cities with a similar levels of physical connectivity.     

Probability Distribution of the Project Payback Period Using the Equivalent Cash Flow Decomposition

For stochastic cash flows, probabilistic approaches to determine a complete distribution of payback period are very limited. The payback analysis based on the net present value (NPV) has several advantages. For annual cash flows, however, the NPV-based method does not provide a complete payback distribution. This article proposes a new technique, the equivalent cash flow decomposition (ECFD), which converts an annual cash flow into an equivalent subannual cash flow at a desired level of precision. The ECFD technique can be used in conjunction with any probabilistic cash flow technique. This article demonstrates that the ECFD technique overcomes the discontinuity limitation of the conventional NPV-based payback period method and generates a complete distribution of the payback period of annual cash flows. Examples indicate that the proposed method is robust with the accuracy comparable to Monte Carlo simulation.     

复杂耦合网络交通动力学模型研究

为了准确反映网络的交通行为,提出一种基于复杂耦合网络的改进交通动力学模型。对双层结构耦合网络的信息产生和传递情况进行分析,并探讨了复杂耦合网络信息交通过程的特征,引入层间控制参数和层内控制参数分别控制不同层之间信息传递的速度和路径选择,重点考虑了层间传递信息的损耗代价情况。在所提动力学模型的基础上,研究了耦合网络中信息交通过程涌现出的统计学特征。结果表明：提出的耦合网络交通动力学模型中所有节点都能够产生和传递信息,随着层内控制参数的增大,网络交通容量出现先增大后减小的变化趋势,当层内控制参数为3.8时,耦合网络交通容量达到最大。研究结果对交通网络中的拥塞问题的缓解具有指导意义,可以通过调整控制参数来增大网络的交通容量。     

Citizen-centered big data analysis-driven governance intelligence framework for smart cities

Sensors and systems within rapidly expanding smart cities produce citizen-centered big data which have potential value to support citizen-centered urban governance decision-making. There exists a wealth of extant conceptual studies, however, further operational studies are needed to establish a specific path towards implementation of such data to governance decision-making with analytical algorithms that are appropriate for each step of the path. This paper proposes a framework for the use of citizen-centered big data analysis to drive governance intelligence in smart cities from two perspectives: urban governance issues and data-analysis algorithms. The framework consists of three layers: 1) A data-merging layer, which builds a citizen-centered panoramic data set for each citizen by merging citizen-related big data from multiple sources in collaborative urban governance via similarity calculation and conflict resolution; 2) a knowledge-discovery layer, which plots the citizen profile and citizen persona at both individual and group levels in terms of urban public service delivery and citizen participation via simple statistical analysis techniques, machine learning, and econometrics methods; and 3) a decision-making layer, which uses ontology models to standardize urban governance-related attributes, personas, and associations to support governance decision-making via data mining and Bayesian Net techniques. Finally, the proposed framework is validated in a case study on blood donation governance in China. This research highlights the value of citizen-centered big data, pushes data-to-decision research from conceptual to operational, synthesizes previously published frameworks for citizen-centered big data analysis in smart cities, and enhances the mutual supplement cross multiple disciplinaries.     

螺杆泵试验转速和黏度对水力特性检测的影响

螺杆泵水力特性检测．一方面可以为螺杆泵科研项目的研究开发提供依据,另一方面可以实现产品质量检验,控制不合格品进入市场？应用螺杆泵水力特性检测装置,开展了水力特性试验并对实验结果进行了转速、黏度校正。通过对校正前后的结果对比分析表明：螺杆泵的试验转速、试验介质黏度偏差对螺杆泵水力特性参数如排量、客积效率、轴功率、总效率存在影响且不可忽略．并随泵型增大而偏差越来越大．在水力特性检测中应给予足够的重视：提出了校正方法。     

国内外深隧排水系统建设状况及其启示

目前中国城市内涝问题难以控制,排水系统建设历史欠账太多,难以突破。对比发达国家,深层隧道排水技术是中国的盲点。从用途进行分类,详细阐述国内外发达城市发展过程中遇到的防洪排涝问题,以及深层隧道排水工程在城市排水系统中的地位和作用,为中国未来的深层隧道排水规划提供参考。