基本农田划定中的耕地立地条件评价研究

良好的耕地自然质量条件和稳定的立地条件是永久基本农田划定的重要基础条件.目前对基本农田的研究多偏重耕地自然质量条件评价方面,而对耕地立地条件研究较少,基本农田被频繁调整,稳定性差.论文以东港市为研究区域,在保障耕地自然条件良好,均一的基础上,从耕地立地条件角度探讨基本农田划定问题,由耕地区位条件因素和耕作便利条件因素构建耕地立地条件评价体系,采用指数衰减法等计算立地条件因素影响作用分值,利用相关性分析等数学模型分析立地条件因素对基本农田划定影响风险范围以及稳定区域,并以实证分析.研究结果表明:1)立地条件是永久基本农田划定的重要组成部分,对基本农田的稳定性影响较大;2)区位因素对基本农田划定存在一定距离的负向型影响,该距离内被占用风险较大,风险距离外区位因素影响为正向型,并呈同心圆状逐级衰减;3)辽宁省东港市立地条件评价结果分4个等级,其中1,2,3级耕地立地条件较优,面积为89 954 hm²,占耕地总面积的86.3%,区位较优,耕作便利,适宜划入基本农田.     

Pharmaceutical compounds in aquatic environment in China: locally screening and environmental risk assessment

An environmental risk assessment was performed for pharmaceutical compounds present in the aquatic environment of China. Predicted environmental concentration (PEC) of the compounds were calculated according to European Medicines Evaluation Agency (EMEA) guidelines. Available ecotoxicological data compromised by applying a very conservative assessment factor (AF) were employed to calculate the predicted no-effect concentration (PNEC). The screening principle and the risk assessment were based on risk quotient (RQ), which derived from the PEC and related PNEC values. PEC results indicated that all the compounds except sulfadimethoxine and levocarnitine, should carry out phase II risk assessment in EMEA guideline. RQ values suggested that more than 36 pharmaceuticals may be imposed health threats to the aquatic environment; especially the antibiotic therapeutic class including amoxicillin, sulfasalazine, trimethoprim, oxytetracycline and erythromycin showed high RQ values. These substances with high RQ value (RQ≥1) were regarded as top-priority pharmaceuticals for control in the aquatic environment of China. However, the antibiotic substances which had low risk quotient (RQ <1), should be reassessed by its potentially induced resistance under low concentration in future.     

区域空气质量监测网络优化布点方法研究

通过分析区域空气质量监测网络(RAQMN)优化布点的各种限制因素,利用空气质量模型模拟数据构建综合评价浓度,建立以最大贴近度为优化目标,以建设成本、地形、行政区域、人口布局和空间覆盖率等为约束条件的RAQMN优化布点方法.以珠江三角洲为案例背景,利用此方法分析了考虑常规污染物(SO2、NO2和PM10)、区域特征污染物(O3和PM2.5)和同时考虑包括常规、区域特征污染物等多种污染物组合3种情景下的RAQMN的优化布点.结果表明,该方法能够成功地应用于RAQMN的优化选址.与仅考虑常规污染物和仅考虑区域特征污染物的优化结果相比,同时考虑多种污染物优化结果的空间代表性更好,更能满足RAQMN的监测目标与优化布点的要求.     

Optimization of regional hazardous waste management systems: an improved formulation

The planning and design of regional hazardous waste management system (RHWMS) involves selection of treatment and disposal facilities, allocation of hazardous wastes and waste residues from generator to the treatment and disposal sites and selection of the transportation routes. An improved formulation based upon multi-objective integer programming approach is presented to arrive at the optimal configuration of RHWMS components. This formulation addresses important practical issues like unique characteristics of the hazardous wastes reflecting on waste–waste and waste–technology compatibility. A utility function approach is presented to integrate both cost and risk related objectives. An illustrative case example is presented to demonstrate the usefulness of the improved formulation as a tool which can be used by environmental planning agencies in regional planning for hazardous waste management.     

城市大气环境监测优化布点模糊优选模型及应用实例

文章根据城市大气环境监测优化布点的模糊性,提出了一种模糊环境条件下的模糊聚类与模糊识别理论模型,并且在山东省肥城等市成功应用。结合统计方法确定出的大气监测优化点位,不但具有代表性和整体性,而且具有较高的分辨率,能快速准确地、最大范围地反映出该区域的环境空气质量状况、大气污染扩散规律、污染源分布特点、污染气象及地理位置特征,为环境管理和政府决策提供可靠依据。     

城市消防站选址布局优化及对雄安新区的启示

安全是雄安新区建设发展的重要保障和基础底线。消防救援队伍,承担火灾防范、火灾扑救、抢险救援等工作,是提升新区城市救援能力,保障城市安全的有生力量。消防站是消防救援队伍工作（执勤备战）的场所,优化消防站选址布局意义重大。面向雄安新区消防安全提升和应急救援能力提升需求,针对我国目前消防站建设过程中覆盖率低及消防站建设投资巨大等问题,建立位置集合覆盖模型和最大覆盖模型联合使用的选址方法,增加补充性约束条件对模型进行改进,提出基于GIS的选址模型应用流程,并通过实际案例应用研究,提出雄安新区消防站规划建设的启示建议。     

基于稳态模型的井下抽采主管道泄漏检测方法研究*

为准确检测煤矿井下瓦斯抽采主管道泄漏位置,提出基于稳态模型的管道泄漏检测与定位方法,采用Comsol数值模拟及地面相似实验研究压力梯度法对煤矿井下抽采管道泄漏检测与定位的可行性及准确性。研究结果表明:管道未泄漏时,管内沿线压力呈均匀分布,当管道突发泄漏时,管内压力分布呈现明显弯折现象,弯折处即为管道漏点位置,并对管道阻力计算公式进行修正,提高了检测准确性;随着管道泄漏程度的加大,湍流效应显著增强,漏点处速度、压力产生明显突变,且当其他条件恒定时,随着管道泄漏孔径的扩大,管道的漏入量越大,定位的相对误差越小;在宏岩矿开展地面相似实验,实验结果绝对误差为4.5 m,相对误差为6%;在阳煤五矿井下8421抽采巷进行现场应用,绝对误差134 m,相对误差约7.95%。     

1种结合图像处理及深度校正模型的室内早期火灾定位方法

(1.南京信息工程大学 大气物理学院,江苏 南京 210044;2.南京信息工程大学 地理科学学院,江苏 南京 210044;3.南京信息工程大学 应用气象学院,江苏 南京 210044)     

基于改进逼近理想解排序(TOPSIS)法的应急系统优化选址模型研究

通过分析影响应急系统选址的各种因素,建立衡量应急系统地址优劣的指标体系,并利用层次分析法确定各指标的权重。依据改进逼近理想解排序(TOPSIS)法的基本思路,建立应急系统优化选址模型。通过具体的实例说明,将改进TOPSIS法引入选址模型是解决应急系统优化选址问题的有效方法,是选址方法体系的一种创新思路。     

Tidal salt marsh sediment in California, USA: part 3. Current and historic toxicity potential of contaminants and their bioaccumulation

To assess potential health risks to benthic organisms from exposure to toxic contaminants, sediment chemistry data from five salt marshes along the coast of California were compared with threshold effects levels (TELs) and probable effects levels (PELs). As an integrated estimate of toxicity potential of multiple contaminants, mean PEL quotients (mPELQs) were used to categorize sampling stations into three groups: high (>0.5), medium (0.1–0.5) and low (<0.1). In all sediments from Stege Marsh located in San Francisco Bay, at least one contaminant exceeded PELs by up to 18-fold and mPELQs were higher than 0.7. Mean PELQs in two core sediments from eastern Stege Marsh ranged from 0.7 to 2.1, indicating that benthic organisms in Stege Marsh may have been adversely affected for several decades. To investigate bioavailability and bioaccumulation of contaminants in sediments, longjaw mudsuckers (Gillichthys mirabilis) were transplanted to six Stege Marsh stations for 60 days. Body burdens of organic contaminants clearly showed that they were readily available for benthic organisms. Measured concentrations of organic contaminants in mudsuckers were similar to estimated levels computed using a theoretical bioaccumulation potential model. Levels of PCBs and arsenic in mudsuckers were higher than screening values set as guidelines for the protection of humans and levels of PCBs and DDTs were higher than criteria for wildlife. The results of this study indicate that the levels of contaminants in Stege Marsh sediments may not fully support the well-being of benthic organisms and also may provoke adverse effects on fish-eating animals and humans through trophic transfer.