A NEW METHOD FOR DIAGRAMMING PACEMAKER/HEART INTERACTION

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校园智能调频广播系统

列出了一种校园智能广播系统的解决方案,并从微机控制的角度,说明实现多种广播功能的机理.     

车用发动机气门电动化的可行性研究

分析了以凸轮为驱动力的配气机构辅以配气相位调整装置所实现的各种配气相位可变控制技术的结构特点及存在的不足,介绍了电动气门的工作方式及性能特点,阐述了汽车电源电压升级的可能性及车用发动机气门电动化的可行性。     

北京至唐山城际铁路建设时机研究

论文首先分析了我国进出关铁路通道的布局、各进出关口的功能及现状运量,然后根据对历史数据和未来发展形势的分析,在获得全国铁路进出关客货运量水平的基础上,对通道各个关口进行分工,得出京唐通道客货运总量预测结果,再将需求预测结果与线网能力进行能力适应分析。经过计算,京哈线北京至唐山段2020年能力利用率为96.8%,已基本饱和;2025年能力利用率为113.9%,能力不足,故2025年前京哈线北京唐山间需要修建新线;通过对替代方案分析,结合京津冀地区土地开发前景,确定结合修建北京枢纽东南环线新建京唐城际的建设方案。     

沥青混合料中沥青含量及矿料级配试验方法分析

根据几年来高速公路材料试验检测的实践,对沥青混合料中沥青含量及矿料级配检测的试验方法、特点及仪器使用情况做了系统分析。     

公路工程预防性养护

介绍了公路工程预防性养护的概念,对比了国内外预防性养护的发展现状,介绍了预防性养护的具体方法及其适用条件,并对现存的以及进一步需要研究的问题进行了阐述和展望。     

干道交织区通行能力最大化的合流车道控制

城市干道交织区内大量的车辆交织将严重降低道路的通行能力,本文根据车辆交织行为及各汇入车道交通量的不均衡性,提出了交织区合流车道信号控制方式.采用交织折减系数,建立了车道控制下的交织区实际通行能力计算模型;随后,以交织区内实际通行能力最大为目标函数,交织区内交织比例和相位控制方案为约束条件,提出了合流车道最优信号配时模型;最后以实际数据进行验证,汇入控制的实际通行能力与模型计算结果的误差仅为2.44%,验证了通行能力计算模型的有效性.模型计算结果表明：随着高峰期间汇入交通量的增加,交织区内存在大幅度的通行能力骤减,采用分车道信号控制后,交织区的实际通行能力与实际过车数得到明显提升.     

CO2和H2对HCCI二甲醚发动机燃烧影响的数值模拟

模拟了燃用DME的HCC I发动机的燃烧过程,研究了进气添加剂CO2和H2对其着火时刻和指示功的影响。结果表明:CO2能延迟着火时刻,降低缸内压力和温度,从而扩大HCC I燃烧运行范围;H2也可推迟着火,并能有效提高发动机的指示功。为了既控制着火始点,又提高发动机指示功,提出进气中同时添加适量CO2和H2,并就此进行了计算。     

Port investments on coastal and marine disasters prevention: Economic modeling and implications

Located along shorelines, seaports are highly vulnerable to coastal and marine natural disasters largely due to climate change. Damage caused by disasters can be prevented or alleviated if sufficient investments are made in a timely manner. However, despite a wide range of investment options and well-developed engineering expertise, port investment on disaster prevention remains a challenging task involving great complexities. This paper develops an integrated economic model for the analysis of disaster-prevention investments at a “landlord” port. It simultaneously considers the uncertainty of disaster occurrence and associated return of prevention investments, the information accumulation and related investment timing, and the benefit spillovers of investment among stakeholders. Our analysis shows that the timing of port investments depends on the probability of disasters. Immediate investment is optimal for disasters with very high probability, while investment should be postponed if such a probability is very low. Optimal timing for cases of intermediate probability cannot be determined analytically, as it is influenced by other factors such as discount rate, information accumulation and efficiency of investments. Positive spillovers between a port and its tenants lead to under-investment, which can be corrected by coordination between stakeholders. However, since there are risks of “overinvestment” (the marginal benefits of investments are zero ex post if there is no disaster), regulatory intervention is not always optimal when the regulator does not have a good understanding of disaster probability distribution. Therefore, scientific research would bring significant economic and strategic value to policy, planning and investment decisions.     

虾峙门口外30万吨级人工航道扩建

针对我国第一条30万吨级人工航道的扩建,从现状航道通航饱和度、核心港区船舶流量上升趋势、船舶大型化及靠泊需求等方面对航道扩建必要性进行阐述,通过对延长航道乘潮历时与航道通航能力的适应性分析,合理确定航道扩建规模和方案,对航道扩建后的水流条件改善、回淤、尺度模拟、船舶进槽和靠泊时机的匹配性等扩建效果进行系统研究,提出在现有航道基础上增深至-23.5 m、拓宽至440 m的扩建方案,通航效果良好,可满足到港船舶安全过槽及一潮靠泊的通航需求。