Application of game theory in risk management of urban natural gas pipelines

This paper presents a game theory methodology for risk management of urban natural gas pipelines, which is a collaborative participation mechanism of the stakeholders, including government, pipeline companies, and the public. Firstly, the involvement proportion of stakeholders in risk management under rational conditions is estimated by the static game theory. Subsequently, the system dynamics (SD) simulation is used to establish an evolution game model of stakeholders in risk management under the irrational conditions, in which the stability of the evolution game process is analyzed. The stakeholders’ involvement proportions from the static game model are utilized as the inputs for the evolution game model to simulate the dynamic evolution behavior of risk management strategies with different involvement proportions of stakeholders. Eventually, the dynamic evaluation game can extract an optimal strategy for risk management of urban natural gas pipelines. A case study is used to illustrate the methodology. In essence, this methodology can be extended for implementing risk management of urban infrastructure.     

颗粒污泥的风干过程及其结构特征

采用SBR反应器培养丝状菌颗粒污泥,反应器运行第18、23、27 d依次出现普通好氧活性污泥黄色颗粒、黑色丝状真菌颗粒,及具有光滑表面的白色微丝菌颗粒.对出现的以上3种颗粒污泥进行风干实验,分析了不同类型颗粒表面结合自由水和毛细水的分布特性：丝状菌形成的黑色和白色颗粒表面结合的自由水分别为79%和83%,而传统的以细菌...     

混凝沉淀对净水工艺中仙女虫的控制研究

为有效应对O3-BAC工艺引起的净水工艺中仙女虫污染风险,进行了混凝沉淀对仙女虫控制效果研究.首先进行了自来水厂混凝沉淀单元仙女虫现场采样分析,再结合仙女虫混凝沉淀去除的烧杯实验和沉淀池迁移模拟实验,分析探讨混凝沉淀对仙女虫的去除规律和控制效果.结果表明,自来水厂混凝沉淀和烧杯实验条件下的混凝沉淀均对仙女虫去除效果明显...     

基于微台阶法对连拱隧道稳定性的研究

为研究软弱围岩基于微台阶法连拱隧道合理的掌子面纵向间距、仰拱一次开挖长度和开挖进尺施工参数,确保隧道安全和高效施工,以云南省元蔓高速公路风口山隧道为研究对象,从力学机理上分析了施工参数对隧道稳定的影响,采用数值模拟方法,分析纵向间距对中隔墙水平位移和开挖面叠加效应的影响、仰拱一次开挖长度对拱腰水平位移和中隔墙受力的影响、开挖进尺对围岩变形特征和掌子面剪应力的影响,对连拱隧道微台阶法进行最优化设计。结果表明,掌子面纵向间距2D、仰拱一次开挖长度4 m、开挖进尺2m为宜,可为类似连拱隧道的施工提供指导。     

悬浮态水泥生料固硫效率试验研究

在水泥工业领域,水泥生料作为悬浮预热预分解系统脱硫过程中的固硫剂,为了研究固气比、温度、气体流速、SO2浓度以及水泥生料比表面积对悬浮态水泥固硫效率影响规律,采用水泥工厂的生料,利用悬浮电阻炉对水泥生料固硫效率进行试验研究,研究发现固气比和温度对水泥生料固硫效率影响较大。     

SBR策略控制活性污泥培养

着重分析了在以SBR方式启动的活性污泥自培养过程周期内的氨氮、亚硝酸盐、硝酸盐、SCOD、pH、DO的变化规律。结果表明,在供氧充足的条件下,出现亚硝酸盐的积累是正常的,也是短暂的;不影响培养过程中对污泥量增长的需要,在周期性进出水过程中,COD的去除率达到80%,氨氮的去除率达到100%。通过对这些指标的分析,对于缩短曝气时间,加速反应器的启动有极大的帮助。     

几种工业废水可生化性判定指标的验证与评价

测定了几种工业废水的可生化性指标BOD5/COD比值和相对耗氧速率,根据模拟生物氧化塘的动态运行试验结果,提出以耗氧速率(R％)作为可生化性的判定指标,它比BOD5/COD比值测定快速,方法简便,更接近实际,并得出两个指标与生物塘COD去除率之间相关性的线性回归方程,为选择废水生物塘处理方案、预估其对COD的去除效率提供了理论依据。      

A lagrangian one-layer model of long-range transport of SO2

The daily mean concentrations of SO₂ have been estimated using a simple trajectory model of long-range transport. Seasonal variations in the transformation rate of SO₂ to sulphate are assumed. The mixing height varied from day to day depending on the stability conditions. The dry deposition velocity above the ground varies according to the season, cloud cover and time of day, while a constant value is applied above the sea. Under present model assumptions the variation of pollutant concentration with time at the receptor point arises only due to variable meteorological conditions. During the test period measured concentrations were often higher than estimated. However, the order of magnitude of pollutant concentration was well predicted. In future work, input meteorological data should have a finer resolution. Further, better parameterizations of sulphur dioxide concentrations at the start points of trajectories and wet deposition should be employed.     

同步反硝化聚磷的试验研究

采用SBR反应器和人工合成废水研究了同步反硝化聚磷的条件和影响因素.试验结果表明,厌氧/好氧方式下驯养的生物除磷污泥,在厌氧期之后供给硝酸盐,则污泥可以很快实现同步反硝化聚磷.聚磷前厌氧阶段的存在是实现反硝化聚磷必不可少的重要前提.在没有NO₃^-干扰而且乙酸钠为唯一碳源下,最佳厌氧时间为60min.先于缺氧期微生物接触硝酸盐,会使反硝化聚磷减弱甚至丧失.缺氧段NO₃^--浓度是影响反硝化聚磷效果的因素之一.在厌氧(2h)-缺氧(1h)-好氧(2h)的试验条件下,当NO₃^--N浓度由5mg/L上升至20mg/L时,其反硝化聚磷效率由11.9%上升至48.7%.但NO₃^--N浓度提高到了20mg/L以上时,其效率提高得不很明显.好氧段的存在不会使诱导形成的反硝化聚磷消失,但缩短好氧时间有助于提高DNPA在除磷中的比例.     

砖木旧工业厂房主体结构改造加固的脆弱性评估

为深入评估砖木旧工业厂房改造加固的脆弱性,经过基础理论研究与调研,运用VSD模型（vulnerability scoping diagram）结合该系统4项构成要素,即协同管理、结构特点、施工环境、技术方法,以交叉矩阵形式分析系统脆弱性影响因素。通过SPSS软件进行可靠性检验从而筛选指标,构建以暴露性、敏感性、适应性为核心的评估指标体系。利用熵值法求得指标权重后,结合某砖木结构厂房实例,依据云模型方法建立脆弱性评估模型,运用MATLAB软件计算指标参数,从而量化指标的不确定性。评估结果识别出保护性拆除方案、抗震构件的设置和保护性修复政策3个最脆弱因素及相应控制最有效的3个关键因素,相比灰色关联分析结果更具优越性,为今后旧工业厂房改造加固工程的施工管控提供了借鉴。