我国大气环境监测质量控制及优化策略研究

随着各地雾霾等大气污染问题反复出现,各种复杂的大气环境质量问题开始在全球集中呈现。大气污染物在环流扰动之下已经开始了长距离传输,不再是过去单纯的点源污染,而是表现出了蔓延速度更加迅速、污染更加复杂的情况,加强大气环境监测工作刻不容缓。因此本文以大气环境质量现状为出发点,对目前我国大气环境质量监测中存在的问题进行了分析,并就此提出了完善我国大气环境质量监测工作的对策,希望能推动我国大气环境质量的进一步改善。     

大气磷干沉降采样方法对比分析

以四川农业大学成都校区为监测点,采用大气主动采样法(AA)、大气干表面法(ADS)及大气湿表面法(AWS)3种常用干沉降采集方法做大气磷干沉降通量对比试验。结果表明,3种采样方法获得的大气磷干沉降通量间具有显著的差异性及相关性(P0.05),三者间可以进行换算统一;AA法适用于较短采样周期的连续性监测研究,ADS法适用于较长采样周期(5 d)的监测研究,而AWS法更适用于在长采样周期(月)内选取一段时间作为干沉降监测的研究。     

A preliminary analysis of the surface chemistry of atmospheric aerosol particles in a typical urban area of Beijing

Atmospheric aerosol particle samples were collected using an Ambient Eight Stage(Non-Viable) Cascade Impactor Sampler in a typical urban area of Beijing from 27 th Sep.to 5th Oct.,2009.The surface chemistry of these aerosol particles was analyzed using Static Time of Flight-Secondary Ion Mass Spectrometry(Static TOF-SIMS).The factors influencing surface compositions were evaluated in conjunction with the air pollution levels,meteorological factors,and air mass transport for the sampling period.The results show that a variety of organic ion groups and inorganic ions/ion groups were accumulated on the surfaces of aerosol particles in urban areas of Beijing;and hydrophobic organic compounds with short-or middle-chain alkyl as well as hydrophilic secondary inorganic compounds were observed.All these compounds have the potential to affect the atmospheric behavior of urban aerosol particles.PM1.1–2.1and PM3.3–4.7had similar elements on their surfaces,but some molecules and ionic groups demonstrated differences in Time of Flight-Secondary Ion Mass Spectrometry spectra.This suggests that the quantities of elements varied between PM1.1–2.1and PM3.3–4.7.In particular,more intense research efforts into fluoride pollution are required,because the fluorides on aerosol surfaces have the potential to harm human health.The levels of air pollution had the most significant influence on the surface compositions of aerosol particles in our study.Hence,heavier air pollution was associated with more complex surface compositions on aerosol particles.In addition,wind,rainfall,and air masses from the south also greatly influenced the surface compositions of these urban aerosol particles.     

廊坊市大气环境质量与环境容量研究

根据廊坊市2003～2008年空气监测数据,采用灰色模型GM(1,1)对该市大气环境质量主导因子PM10、SO2和NO2进行模拟预测,采用宏观总量控制A值法对理想大气容量进行计算分析,最终建议在工业污染源、生活污染源、交通污染源和建筑扬尘污染源4个方面采取必要措施保护廊坊市的大气环境。     

辽宁省大气湿沉降化学特征分析

通过分析降水酸度、化学特征和湿沉降量等酸沉降控制指标,得出2009年辽宁省大气湿沉降化学特征。研究发现,辽宁省总体上酸雨污染并不严重,但区域性污染突出;降水化学污染严重,呈地域分布不平衡特征,重污染城市位于辽宁省西部和中部;湿沉降量的空间分布与降水化学污染不同,沉降量大的城市位于东部和南部沿海,所有离子湿沉降量最大值均出现在夏季。     

The oxidation mechanism of polychlorinated dibenzo-p-dioxins under the atmospheric conditions - A theoretical study

The atmospheric polychlorinated dibenzo-p-dioxins (PCDDs) partition appreciably in the gas phase, where they undergo rapid oxidation. The atmospheric oxidation mechanisms of a few PCDDs, initiated by OH radical, are studied using density functional theory calculations. The oxidations start with OH-addition to the aromatic rings, dominantly at γ-sites, followed by the non-chlorinated β-sites; while additions to the α-sites or chlorinated sites are negligible. For PCDDs with all β-sites being chlorinated, formation of PCDD-γ-OH adducts become virtually the only reaction path. Under the atmospheric conditions, the PCDD-β/γ-OH adducts combine with O₂ slowly at rates <1 s⁻¹. Instead, the PCDD-β-OH adducts will react with O₂ through hydrogen abstraction at rates <50 s⁻¹, forming PCDD-β-ol, and the PCDD-γ-OH adducts will decompose to the substituted phenoxy radicals by fused-ring C-O bond cleavage at rates of 10³ ∼ 10⁵ s⁻¹. The reaction mechanisms of PCDDs are drastically different from the peroxy mechanism for the atmospheric oxidations of benzene and dibenzofuran.     

Review on recent progress in on-line monitoring technology for atmospheric pollution source emissions in China

Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China, and its components, which include ultrafine particles (UFPs), volatile organic compounds (VOCs), and other reactive gases, such as NH₃ and NO_x, are the most harmful to human health. China has released various regulations and standards to address pollution from mobile and stationary sources. Thus, it is urgent to develop online monitoring technology for atmospheric pollution source emissions. This study provides an overview of the main progress in mobile and stationary source monitoring technology in China and describes the comprehensive application of some typical instruments in vital areas in recent years. These instruments have been applied to monitor emissions from motor vehicles, ships, airports, the chemical industry, and electric power generation. Not only has the level of atmospheric environment monitoring technology and equipment been improving, but relevant regulations and standards have also been constantly updated. Meanwhile, the developed instruments can provide scientific assistance for the successful implementation of regulations. According to the potential problem areas in atmospheric pollution in China, some research hotspots and future trends of atmospheric online monitoring technology are summarized. Furthermore, more advanced atmospheric online monitoring technology will contribute to a comprehensive understanding of atmospheric pollution and improve environmental monitoring capacity.     

基于故障物理和数理统计相结合的可靠性加速试验方法

目的 研究通过加速试验在较短时间内对高可靠性、小子样电子产品的可靠性进行评估的方法.方法 分析可靠性加速试验方案的特点,梳理可靠性加速试验方案制定的基本流程,通过结合数理统计和故障物理技术,研究加速应力的确定方法和加速因子的计算模型,给出加速试验条件及试验时间的确定流程以及相应的试验结果评估方法,并进行案例应用.结果 该方法克服了常规可靠性加速试验方案设计中仅依靠经验并需要大样本量的缺点,科学有效地解决了高可靠性、小样本产品的可靠性加速试验方案设计问题,形成了电子设备基于故障物理和数理统计相结合的可靠性加速试验方案设计方法,经验证合理可行.结论 该试验方法能够满足当前可靠性要求高、进度紧、受试样品有限的武器装备研制的需求.     

面向制信息权的核污染扩散预警技术研究

以核电站核污染扩散预警技术为研究对象,基于环保指挥自动化系统C4ISRE,通过整合WRF、HYSPLIT、Unidata IDV、AGI STK、Arc GIS系统等构建核污染扩散单一合成图SIP(Single Integrated Picture),并通过SIP对核污染扩散进行详细分析,进而实现对核污染应急处置的制信息权。研究表明:当研究区实际的天气系统具备了本例模拟的气象特征时,即主体风向为局部区域东北风3~4级,局部区域西北风6~7级,发生与日本福岛核事故同样等级的事故,12个小时后,受影响的居民区主要为谢屯镇、炮台镇、李店镇、普兰店市、无名区1。其中,炮台镇的大部分区域浓度为10 Pbq,面积为2.66 km 2,东北方向部分区域浓度为100 Pbq,面积为0.03 km~2;普兰店市西南部区域浓度为10 Pbq,面积为8.00 km~2,东北部区域浓度为100 Pbq,面积为0.033 km 2;李店镇东北区域浓度为1 Pbq,面积为0.93km~2;无名区1南部区域浓度为1 Pbq,面积为4.50 km~2。     

生态保护红线在实践过程中的问题剖析——以湖北宜昌为例

宜昌市生态保护红线于2015年1月正式颁布实施,文章结合宜昌市生态保护红线的应用情况,剖析了生态功能红线、水环境质量红线及大气环境质量红线在实践过程中存在的主要问题,同时,对生态保护红线管理机制需要解决的重点问题进行了阐述。