基于修正场模型的区域空间结构演变及空间整合〖HT2”SS〗——以泛长江三角洲为例

随着长江三角洲经济发展及其面临问题,长三角泛化已成为必然,研究泛长三角空间结构演变有利于正确认识和把握其空间发展态势,从而为泛长三角区域一体化进程提供问题依据。以场强模型为基石,根据扩散理论,构建了场对数扩散效应模型,从城市场这一新视角分析了泛长三角区域空间演进过程。泛长三角城市影响区自改革开放以来经历了疏点-“之”-“几”-“皮皮虾”-“鳊鱼”5种空间形态;根据这一空间形态极其演变规律提炼出疏点类型、散块类型、条带类型、团块类型、板块类型五种空间结构类型;在此基础上,由“以点建轴,以轴布面”思想,以产业结构整体升级为引导,对泛长三角区域进行空间整合,形成由三级中心城市、三级发展轴线以及内核城市群、邻接城市群和外缘城市群组成的核心-边缘结构三级产业城市群。     

北京冬季雾霾频发期VOCs源解析及健康风险评价

采用低温固体吸附采样、热脱附-气相色谱-质谱联用的方法对北京冬季雾霾频发期空气中挥发性有机物(VOCs)进行了连续监测,对以雾霾期为标志划分的4个阶段的VOCs浓度水平与组成变化特征进行了分析研究,利用正矩阵因数分解模型(positive matrix factorization,PMF)对VOCs的可能来源进行解析,并进行了健康风险评价.结果表明,VOCs的日均浓度为332.34μg·m~(-3),苯系物和卤代烃在研究区域大气环境的VOCs中含量占主导地位;冬季雾霾的主要污染物排放源为溶剂/涂料使用及机动车尾气排放;区域所检出的致癌性VOCs的致癌风险均超过了EPA给出的风险限值.     

循环经济发展评价的生态效率测算模型及应用

生态效率是基于可持续发展的思想,鉴于循环经济发展和实际环境的需求,通过构建循环经济发展评价的生态效率测算模型,针对循环经济中资源和环境2个重要方面,选择实例进行模型的应用。所选择研究对象经过测算,生态效率在"十一五"期间呈现波动上升,在5年时间增长了1.1倍,但仍处于末端治理为主的循环经济发展阶段,较为客观地反映了当地循环经济的发展轨迹。通过相关分析和说明,为循环经济发展评价提供生态效率分析这一方案选择。     

The separation of reinforced cementitious composites with a stream-line cutting tool

The paper provides a model for the cutting of reinforced concrete members with stream-line cutting tools. The model is an extended version of the energy model originally developed by Momber and Kovacevic (1995) for hydro-abrasive machining. The model allows the stepwise calculation of the energy absorbed during the cutting of the two parts of the compound - steel bar and matrix material. Hydro-abrasive cutting tests on different cementitious composites are performed in order to verify the numerical results. It is shown that the cutting process can be subdivided into four cutting stages whose locations depended on the energy locally available at the erosion site.     

Methodology for Developing Flood Rule Curves Conditioned on El Niño‐Southern Oscillation Classification1

Lee, Se‐Yeun, Alan F. Hamlet, Carolyn J. Fitzgerald, and Stephen J. Burges, 2011. Methodology for Developing Flood Rule Curves Conditioned on El Niño‐Southern Oscillation Classification. Journal of the American Water Resources Association (JAWRA) 47(1):81‐92. DOI: 10.1111/j.1752‐1688.2010.00490.x Abstract: Regional climate varies on interannual and decadal time scales that in turn affect annual streamflows, flood risks, and reservoir storage deficits in mid‐summer. However, these variable elements of the climate system are generally not included in water resources operating policies that attempt to preserve a balance between flood risk and other water resources system objectives. A methodology for incorporating El Niño‐Southern Oscillation (ENSO) information in designing flood control curves is investigated. An optimization‐simulation procedure is used to develop a set of ENSO‐conditioned flood control rule curves that relate streamflow forecasts to flood control evacuation requirements. ENSO‐conditioned simulated flood risk and storage deficits under current operating policy are used to calibrate a unique objective function for each ENSO classification. Using a case study for the Columbia River Basin, we demonstrate that ENSO‐conditioned flood control curves constructed using the optimization‐simulation procedure consistently reduce storage deficits at a number of interrelated projects without increasing flood risk. For the Columbia Basin, the overall improvements in reservoir operations are relatively modest, and (in isolation) might not motivate a restructuring of flood control operations. However, the technique is widely applicable to a wide range of water resources systems and/or different climate indices.     

Stochastic gravity models for modeling lake invasions

Freshwater aquatic systems in North America are being invaded by many different species, ranging from fish, mollusks, cladocerans to various bacteria and viruses. These invasions have serious ecological and economic impacts. Human activities such as recreational boating are an important pathway for dispersal. Gravity models are used to quantify the dispersal effect of human activity. Gravity models currently used in ecology are deterministic. This paper proposes the use of stochastic gravity models in ecology, which provides new capabilities both in model building and in potential model applications. These models allow us to use standard statistical inference tools such as maximum likelihood estimation and model selection based on information criteria. To facilitate prediction, we use only those covariates that are easily available from common data sources and can be forecasted in future. This is important for forecasting the spread of invasive species in geographical and temporal domain. The proposed model is portable, that is it can be used for estimating relative boater traffic and hence relative propagule pressure for the lakes not covered by current boater surveys. This makes our results broadly applicable to various invasion prediction and management models.     

江苏省空气质量预报与实测结果比对研究

选取2015年1—8月江苏地区NAQPMS、CMAQ、CAMx、WRF-Chem 4个模式预报结果与实测值进行比对分析,结果表明,标准化分数偏差(MFB)为-0.066 5~0.201 1,标准化分数误差(MFE)最大值为0.381 8,均在理想范围内,其中CAMx预报效果相对较好,WRF-Chem有一定误差。4个模式相比,NAQPMS对于PM_(10)的模拟性能较好,各模式对PM_(2.5)模拟性能相近,CMAQ和CAMx对O_3模拟较好,WRF-Chem对CO模拟较好,各模式对SO_2和NO_2的模拟都需进一步优化。     

基于遥感-过程耦合模型的地表蒸散量应用研究

作为陆面过程中地气相互作用的重要过程之一,蒸散发(Evapotranspiration,ET)在地球的大气圈-水圈-生物圈中发挥着重要作用。利用遥感-过程耦合模型BEPS,以中分辨率成像光谱仪(MODIS)数据和NCEP/NCAR再分析资料为主要输入,模拟分析了2007-2009年美国区域的地表ET,同时利用通量观测网AmeriFlux的站点观测数据验证该模型在ET模拟研究中的可靠性与适应。结果表明：12个站点通量实测值与BEPS模型模拟的ET值的相关系数为0.7297(P<0.05),表明BEPS模型能够较好的模拟研究区的地表ET。ET在1年内呈现明显的单峰趋势,5-9月ET值较高,可达60 mm·mon-1以上,最小值在1月份,值为8.39 mm·mon-1,最大值在7月份,值为118.04 mm·mon-1。该区域ET的平均年总量为505 mm·a-1。受地形、气候的影响,ET最高值对应于南部区域,这些地区ET的年总量普遍在600 mm·a-1以上,最高值为1667 mm·a-1,对应的主要覆被类型为草地和农田;中北部和东部的大部分区域ET年总量为400~600 mm·a-1;ET最小值在西部区域,年总量小于400 mm·a-1,对应覆被类型为疏林地和混交林。降水量与ET差值呈现从东向西逐渐递减的趋势,最小值主要分布在西部沙漠。整个研究区域ET与降水量之比的平均值为0.72,由东向西基本呈现增加趋势,在西部以及中北部的部分地区比值达到最大。