基于集对分析的空中交通管制运行风险评价

为了对空中交通管制运行风险进行有效的分析,首先根据SHEL模型确立管制运行风险评价指标体系,它由人的因素、硬件因素、软件因素、环境因素4个方面的17个因素组成;使用熵权法与超标倍数赋权法综合分析确定各指标权重;针对管制运行风险各评价指标的不确定性,利用集对分析理论进行分析,确定评价样本与指标之间的联系度,并对样本进行"同一""差异""对立"的集对分析来确定评价样本风险等级。结果表明,提出的集对分析模型对风险指标的处理结果与实际情况基本相符,可以用于空中交通管制运行风险评价。     

Coffee,its roasted form,and their residues cause birth failure and shorten lifespan in dengue vectors

Environmental Science and Pollution Research - In dengue mosquitoes, successful embryonic development and long lifespan are key determinants for the persistence of both virus and vector. Therefore,...     

Effects of pre-oxidation and adsorption on haloacetonitrile and trichloronitromethane formation during subsequent chlorination

In this study, the effects of pre-oxidants permanganate (PM), persulfate (PS), hydrogen peroxide (PO), and ozone (OZ)) and/or adsorption on pseudoboemite-chitosan shell magnetic nanoparticles (ACMNs) on haloacetonitrile (HAN) and trichloronitromethane (TCNM) formation from aspartic acid (Asp; positive charge) and/or histidine (His; negative charge) were compared. Asp and His apparently do not interact in aqueous solution during chlorination. Asp and/or His can undergo partially oxidation by PM, but are recalcitrant to direct oxidation by PS and PO. Pre-oxidation with OZ decreases the formation of HANs but increases the formation of TCNM. ACMN prefers to adsorb Asp over His in the competitive sorption of coexisting Asp and His because of attractive electrostatic interactions. The rank order for the effect of the pre-oxidants and ACMN adsorption on dichloroacetonitrile and trichloroacetonitrile formation is OZ and ACMN adsorption > PM and ACMN adsorption > PS and ACMN adsorption > PO and ACMN adsorption; that for the effect of the pre-oxidants and ACMN adsorption on TCNM formation is PM and ACMN adsorption > PS and ACMN adsorption > PO and ACMN adsorption > OZ and ACMN adsorption. The favored adsorption of Asp over His by ACMN is weakened by pre-oxidation.

     

Fine particle migration and collection in a wet electrostatic precipitator

Electrostatic precipitation is considered as an effective technology for fine particle removal. A lab-scale wet electrostatic precipitator (ESP) with wire-to-plate configuration was developed to study particle migration and collection. The performance of the wet ESP was evaluated in terms of the corona discharge characteristics, total removal efficiency and fractional removal efficiency. The corona discharge characteristics and particle removal abilities of the wet ESP were investigated and compared with dry ESP. Particle removal efficiency was influenced by discharge electrode type, SO₂ concentration, specific collection area (SCA) and particle/droplet interaction. Results showed that the particle removal efficiency of wet ESP was elevated to 97.86% from 93.75% of dry ESP. Three types of discharge electrodes were investigated. Higher particle removal efficiency and larger migration velocity could be obtained with fishbone electrode. Particle removal efficiency decreased by 2.87% when SO₂ concentration increased from 0 ppm to 43 ppm as a result of the suppression of corona discharge and particle charging. The removal efficiency increased with higher SCA, but it changed by only 0.71% with the SCA increasing from 25.0 m²/(m³/s) to 32.5 m²/(m³/s). Meanwhile, the increasing of particle and droplet concentration was favorable to the particle aggregation and improved particle removal efficiency.

Implications: This work tends to study the particle migration and collection under spraying condition. The performance of a wet electrostatic precipitator (ESP) is evaluated in terms of the corona discharge characteristics, total particle removal efficiency, and fractional particle removal efficiency. The effects of water droplets on particle removal, especially on removal of particles with different sizes, is investigated. The optimization work was done to determine appropriate water consumption, discharge electrode type, and specific collection area, which can provide a basis for wet ESP design and application.     

Medium-scale gasification of oil palm empty fruit bunch for power generation

Journal of Material Cycles and Waste Management - This paper focuses on the performance of oil palm empty fruit bunch (EFB) gasification using a medium-scale downdraft gasifier for power...     

混凝土生态膜污水处理工艺生物相变化研究

通过试验方法,研究了混凝土生态膜污水处理工艺的循环挂膜过程,综合考察了混凝土膜片表面生物膜的生长变化情况,细菌数量及其微型动物的组成演化。同时在挂膜一定时间后投加生活污水,考察对COD、NH3-N的去除率。     

最优环境工程方案遴选模型的建立与应用

根据层次分析法的原理,建立了遴选最优环境工程方案的层次结构模型。模型兼顾了效益与投资,不仅简化了专家或决策者的判断难度,而且判断结果直观,各方案的优劣对比清晰。给合某啤酒废水治理工程项目,介绍了层次分析模型应用于工程方案遴选中的计算过程。结果表明,应用此模型对环境工程方案进行优选比较科学、简便。     

基于文献计量的过去30 a稀土开发环境效应研究综述

稀土开发环境效应是地球环境及可持续发展领域的重要课题,过去30 a以来,全球稀土产量增加了400%,但稀土开发环境效应研究一直缺乏系统综述。以Web of Science核心合集和中国知网（CNKI）数据库为基础,基于定量分析与定性认知相结合的判读方法,对过去30 a以来稀土开发环境效应研究文献进行计量分析并开展讨论,揭示稀土环境效应研究发展特点与发展趋势。研究表明：稀土开发环境效应研究文献从2011年开始呈现快速增长,但研究团体具有明显地方性且协作程度较低;中文文献侧重于稀土开发的宏观环境问题研究,而外文文献则侧重于微观机理研究;中国是重要的知识创造中心,美国是国际合作网络中心;研究主题主要包含环境效应来源、影响因素、环境后果以及技术方法等。未来需要加强稀土开发环境效应的全过程生命周期研究,提升中国合作中心地位,强化对稀土开发的深度认知和数据积累。     

中国固体废物的环境管理与环境监测技术现状

为加强中国固体废物的环境管理和环境监测技术,回顾了中国自１９８５年以来制定的固体放心物环境管理法规制度以及１９８４年至１９９８年颁布的２０多年家或行业的固体废物处置标准体系等固体废物的环境管理状况,着重论述了中国固体废物环境监测技术的发展历史与现状。指出经过２０多年的努力,在固体废物环境监测技术与方法上初步形成了该领域框架体系,有固体废物的采样与制样技术;危险废物的有害特性试验鉴别方法,固体废物具