SBS改性沥青混合料路面施工质量控制

从SBS改性沥青的概念及基本原理入手,结合河北省SBS改性沥青混合料面层铺筑使用情况,就如何改善SBS改性沥青路面施工质量进行论述.     

基于电控喷射技术的燃气发电机组的研制

天然气作为一种清洁能源,其燃烧产生的碳排放物远低于汽柴油的排放物,目前天然气在家庭生活和汽车等领域已经有了广泛的应用。通过探讨燃气发电机组的研制,对燃气机组的燃气进气方式和电控喷射技术的实现等方面进行了详细的分析,对实施我国环保能源的“绿色行动计划”具有重要的意义[1]。     

不同评价方法在电气检测实验室内部质量监控中的应用

实验室内部质量监控常用的评价方法有归一化误差(|En|值)法、z比分法和t检验法.针对电气检测中最常用的电压检测,分别采用3种评价方法分析检测结果,探讨3种方法的差异和适用范围.结果显示,3种方法对此次比对结果的分析结论基本一致,在实际应用中应根据样品特点和比对目的选择合适的评价方法.     

基于贝叶斯攻击图的CBTC系统安全风险评估

先进的无线通信技术、计算机技术在城市轨道交通中的应用,在促使列控系统快速发展的同时,也使得其面临的信息安全风险日益严峻。目前,应用于传统IT和工控领域的信息安全分析方法不能很好地满足基于通信的列车自动控制系统(Communication Based Train Control System, CBTC)对信息安全分析的需求。为了提出对CBTC系统安全进行评估的方法,在分析传统工控系统信息安全标准后,从资产、脆弱性、威胁源三个角度分析CBTC系统的信息安全风险,将贝叶斯攻击图(Bayesian Attack Graph, BAG)应用到CBTC系统风险评估建模中,并以ATS子系统为例,从入侵的攻击路径和对组件脆弱性的利用方式两个方面进行考虑,构建攻击模型,通过扩充BAG模型的节点来更好地描述系统特点。最终得到ATS子系统最易发生的信息安全事件以及在考虑黑客和内部恶意工作人员的入侵时,CBTC系统的风险等级。从构建的模型可以看出,CBTC系统处于安全状态。     

一种新型交流转辙机控制电路在地铁中的应用

城市轨道交通正线多采用交流转辙机,既有的五线制交流道岔控制电路因为动作电路和表示电路合用,常导致2DQJ在转极的时候发生带电动作,产生拉弧现象。而终端站或折返站因道岔动作次数多.造成2DQJ频繁更换。为此,北京地铁八通线率先在城市轨道交通中.将动作电路和表示电路分开.为交流转辙机控制电路提供新的参考。     

燃气轮机电液伺服泵控IGV位置补偿控制研究

以燃气轮机进口可转导叶(IGV)位置控制为背景,本文提出伺服电机-定量泵-液压缸容积控制方案,形成电液伺服泵控IGV技术。分析IGV位置控制作用与原理,建立电液伺服泵控IGV数学模型,提出位置补偿控制策略,通过对系统流量输出、油液压缩与泄漏、软参数时变等进行实时补偿,实现IGV位置高精度控制。依托燃气轮机电液伺服泵控IGV试验平台展开仿真和试验研究,研究结果表明所提出的补偿控制策略具有良好的控制效果,为电液伺服泵控IGV技术的工程应用与推广奠定理论和技术基础,助力燃气轮机的技术升级与产品优化。     

基于三维体验平台的模型质量管控架构设计研究

针对目前船舶生产设计过程中三维模型质量不统一的问题，对船舶生产设计建模特点进行分析，梳理并整合了各专业设计模型质量检查业务需求。基于三维体验平台，对三维模型质量管控架构设计进行研究，提出了船舶生产设计质量管控方法，并制定了质量管控平台框架式设计方案，并借助开发工具进行了功能开发，对模型实施质量闭环管理，实现了对三维模型质量的有效管控。     

Introduction to Special Issue on Tropical Coastal Management

In 1992, scientists at National Estuarine Research Reserve (NERR) sites proposed establishing a national coordinated monitoring program that would attempt to identify and track short-term variability and long-term changes in representative estuarine ecosystems and coastal watersheds. Known as the NERR System-Wide Monitoring Program (SWMP), it currently consists of monitoring water quality and atmospheric variables over a range of spatial and temporal scales. Additional monitoring of ecological resources and land-water use will follow in subsequent components of the program. Water quality monitoring at NERR sites includes measurements of pH, conductivity, temperature, dissolved oxygen, turbidity, and water level. The NERR sites use data loggers that record at 30-minute intervals and relay measurements to internal memory. Standardized protocols assure that sampling, processing, and data management techniques are comparable among sites. Statistical techniques are being used to identify periodicity in water quality variables. Periodic regression analysis indicated that diel periodicity in dissolved oxygen is a larger source of variation than tidal periodicity at sites with less tidal amplitude. Tidal periodicity, however, is more important at sites with a tidal amplitude greater than 1 m. This finding suggests that natural processes controlling dissolved oxygen levels differ among sites depending upon tidal amplitude. Water quality data from the NERR SWMP have also been used to investigate occurrence of hypoxia. Results from analysis of water quality at several reserves indicate that hypoxia occurs but that the percentage of time that dissolved oxygen was less than 28% saturation varied substantially among sites and between years. Most of the hypoxic events occurred in summer but were also observed in winter and fall when low dissolved oxygen is usually not considered a problem. Without continuous monitoring by the NERR SWMP, many low dissolved oxygen events would have been missed, thus underestimating the duration and potential impact of this type of water quality variability. The NERR SWMP provides a unique opportunity to increase our understanding of how various environmental factors influence estuarine processes. Only by understanding how estuaries function and change naturally over time will we be able to predict how these systems respond to changes in climate and human-induced perturbations.     

International emission regulation in sea transport: Economic feasibility and impact

Emissions from shipping due to the burning of the sulphur content of marine fuels conduce to air pollution in the form of sulphur dioxide and particulate matter. Various international organisations and institutions impose environmental standards on their member states to limit the emission of greenhouse gases. This paper examines both the potential effects of the emerging international maritime emission regulations on the competition between seaports and the potential underlying economic motivations fostering the discussion of introducing Emission Control Areas. It focuses on deepsea shipping. Another novelty is that the environmental issues are addressed from a policy, an economic and a legislative viewpoint. For the policy-related part, it is found that the political theory of public choice suggests that not the green lobby but rather the petrochemical lobby is the major driving factor behind the very strict emission caps. A potential port shift from Northern Europe to Mediterranean ports seems unlikely due to logistics disadvantages and service problems in Southern European ports. Finally, no convincing proof was found that the main liner companies would be unprepared for this legislation and should be persuaded to change their routes in favour of Mediterranean ports solely on account of the various emission regulations. The legal analysis, however, showed that the current enforcement regime of MARPOL Annex VI should be improved in order to rule out the possibility of a low degree of compliance and to protect the competiveness of complying ships.     

轨道交通综合监控系统测试流程及测试方案设计

综合监控系统具有互联子系统多,监控对象多等特点,使得系统测试工作量大且繁杂.结合苏州轨道交通1号线综合监控系统实际情况,对综合监控系统的测试流程进行了介绍.