公务艇技术经济性评价指标分析及论证

根据公务艇的自身特性,参照GB11697—89的相关规定,建立了一套适用于公务艇技术经济性能分析的评价指标体系和计算方法。实践证明：此评价指标体系可对公务艇的技术经济性进行有效分析,并评估其是否达到目标要求,便于指导今后的设计工作;同时,此评价指标体系也是对有关船舶与海洋结构物性能水平等级评价体系国家标准的有益补充。     

舰船电力系统网络结构分析

阐述了单电站三种电力网络、两电站两种电力网络和多电站三种电力网络的设计原理和技术特点,分析不同电力网络形式对舰船电力系统生命力和可靠性的影响;以几种典型电力网络方案为例,计算各电力网络结构的供电概率,提供舰船电力系统网络设计建议。     

Information Required for Integrated Coastal Zone Management: Conclusions from the European Demonstration Programme

This article presents the results of the Thematic Study on "the role of information in delivering Integrated Coastal Zone Management (ICZM) in Europe." It provides a definition of information and discusses the need for, and nature of, information as it influences and supports ICZM. The conclusions from the study are summarized, highlighting the importance of viewing information provision as part of the process of developing effective ICZM. The results of InfoCoast '99, a symposium held in February 1999 on knowledge and information for coastal management, are discussed and some of the practical steps that have and can be taken to meet the information need for ICZM in Europe are considered.     

Biological Status Assessment of Coral Reefs in Southern Puerto Rico: Supporting Coral Reef Protection Under the U.S. Clean Water Act

Abstract

States and other jurisdictions may protect coral reefs using biological water quality standards outlined by the United States Clean Water Act (CWA). Such protection will require long-term, regional monitoring of the resource using biological indicators and a probability-based sampling design. A 60-station survey targeting nearshore linear coral reef was conducted across southern Puerto Rico in December 2011 to document the status of reef inhabitants using a probabilistic, regional sampling design. The quantity, type and condition of stony corals, fish, gorgonians, and sponges were documented from each station, providing a robust representation of linear reef status and composition across the region. Fish represented 106 unique taxa and stony corals 32 unique taxa. Benthic organisms (stony corals, sponges, and gorgonians) averaged nearly 12 colonies per square meter, more than half of which were gorgonians. Assessment results can be used as a baseline to compare with future regional surveys to quantify change in reef condition over time (trend). Both temporal and spatial changes can be expected after large-scale disturbances like hurricanes Maria and Irma in 2017. The indicators and probabilistic sampling design support the long-term regional monitoring envisioned by the Environmental Protection Agency to implement CWA protections in Puerto Rico and elsewhere.     

Tracks to Change or Mixed Signals? A Review of the Anglo-Saxon Literature on the Economic and Spatial Impacts of High-Speed Rail

ABSTRACT

The economic development and spatial impacts of high-speed rail (HSR) are quite varied and mixed. Studies of economic impacts of HSR fall into two categories: predictions and empirical observations. We first review studies that examine predicted HSR impacts related to job growth, real estate development, and other economic effects. These are followed by studies examining observed effects of realized projects using the same categories. Several patterns emerge. Predictive studies are largely optimistic of the rail's positive effects. On the other hand, observational studies tend to identify both benefits and shortfalls. Yet, neither of these patterns are universal and depend on a number of other factors. One consistent pattern is that gains associated with HSR appear to be stronger in first-tier cities. Nevertheless, certain small towns and second-tier cities have undergone noteworthy transformations as a result of HSR, especially where the public sector has actively pursued new investment.     

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为识别区域综合交通系统能耗驱动因子,测算其对系统能耗的贡献度,将驱动因素分为规模效应、结构效应和技术效应,采用ASIF数据构造原理和时序列回归法识别各因子的相关性,运用迪氏分解方法建立扩展LMDI分解模型,计算各因子能耗贡献度.计算表明,规模效应和技术效应的影响程度在逐渐减弱,结构效应的影响程度在逐渐增加;运输结构还需要进一步优化,对系统能耗的影响还有很大下降空间;近年来能耗效率已经得到很大提高,但能耗效率对能耗的贡献正在逐渐减弱,未来提高运输强度对降低能耗有明显效果.经实证检验,计算模型可靠、结论可信,能为区域综合低碳交通政策制定提供更科学的依据.     

城市小汽车尾号限行的经济学分析

随着城市化的加快和经济的飞速发展,我国许多大、中城市出现不同程度的交通拥堵。交通拥堵治理问题已成为当前我国城市发展过程中的一个热门话题和难题。本文对交通拥堵的影响因素分析后,从经济学的视角出发,通过分析城市居民实行尾号限行后对小汽车的需求、停车位需求和汽车业影响,指出用尾号限行来治理交通拥堵只会产生短期效益,对城市经济的长期稳定发展没有一点好处,进而对缓解城市拥挤提出一些建议,以便实现我国城市交通的可持续发展。     

浙江省交通运输发展与区域经济增长的均衡关系分析

通过协整分析并建立误差修正模型探讨浙江省经济发展与交通运输发展间短期和长期的均衡关系,并在此基础上通过Granger因果分析探讨浙江省经济发展与交通运输发展间的因果关系。得出浙江省经济发展与交通运输发展间存在长期均衡关系,浙江省经济的增长与交通运输发展间存在着正相关关系的结论。实践证明,浙江省经济的增长在一定程度上推动交通运输的发展。     

预应力道面在机场工程中的优势与应用前景

通过对预应力混凝土道面和普通混凝土道面结构进行结构性能和经济性能对比分析。结果表明:预应力混凝土道面在改善结构整体性,增强结构抵抗环境温度效应能力等方面优于普通水泥混凝土道面;预应力道面在初期建设费用比普通混凝土道面高出16%,但后期养护及改扩建费用前者比后者低,利用净现值法计算总费用最高可降低27.57%。预应力道面可以节约大量资源,显著提高社会效益,在场道工程中是一种值得大力推广的道面形式。     

高职教育专业设置与区域产业的匹配度研究——以黄冈职业技术学院与黄冈市为例

摘要高职教育专业设置与区域产业结构相匹配,是发展高等职业教育的必须选择,也是区域经济社会发展的迫切需要。