预冷冻浓缩系统与气相色谱-质谱法测定空气中苯的测量不确定度评定

根据 Top－down技术中的控制图法,运用预冷冻浓缩系统与气相色谱－质谱联用对苯标准样气进行多次测定。通过计算和评定,得出当苯的测定浓度为100×10^－9时,不确定度为5．1×10^－9。     

A model of the air traffic controller's picture

This paper reviews the development of a model of the air traffic controller's mental image, ‘picture’, or situation awareness, used for controlling air traffic. The computerised model's development, origins and theoretical basis are outlined, and the model is described in some detail in the context of current air traffic operations. The model can be utilised to explore the potential impacts of future automation on the cognitive performance of the air traffic controller. The general potential contributions of the area of cognitive modelling to system design and training in accelerating industries such as air traffic control, are also discussed.     

美国加州空气质量政府管理模式及对中国的启示

中国城市空气污染呈区域化和恶化趋势,亟需突破当前空气质量管理模式的制约.从管理体制和管理内容两方面对美国空气质量政府管理模式的先进经验进行了分析,并与北京市空气质量管理模式进行了初步比较,得出中国空气质量政府管理模式缺乏外部性的考虑;政府部门内部机构按照行政管理过程划分,导致管理成本偏高;决策机制与执行机制未分离,影响行政效率;对污染源的管理不专业;缺乏信息公开和公众参与等问题.建议成立空气质量管理分局,对固定源实行排污许可证管理,对移动源实行统一综合管理,细化面源的管理,建立空气质量管理信息公开平台.     

Residues of 2,4‐D in air samples from Saskatchewan: 1966–1975

Abstract

Residues of 2,4‐D (2,4‐dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966–68 and 1970–75 periods were determined by gas‐liquid Chromatographic techniques. Initially, individual esters of 2,4‐D were characterized by retention times and confirmed further by co‐injection and dual column procedures. Since 1973, however, only total 2,4‐D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible.

Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4‐D, with butyl esters being found most frequently. The daily 24‐hr mean atmospheric concentrations of 2,4‐D ranged from 0.01 to 1.22 μg/m³, 0.01 to 13.50 μg/m³, and 0.05 to 0.59 μg/m for the iso‐propyl, mixed butyl and iso‐octyl esters, respectively. Even when the samples were analysed for the total 2,4‐D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 μg/m. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 μg/m³ of 2,4‐D. In another 40% of the samples, the levels of 2,4‐D ranged from 0.01 to 0.099 yg/m. Only about 30% of the samples contained 2,4‐D concentrations higher than 0.1 μg/m³, with only 10% or less exceeding 1 μg/m³.

None of the samples, obtained with the high volume particu‐late sampler, showed any detectable levels of 2,4‐D, indicating little or no transport of 2,4‐D adsorbed on dust particles or as crystals of amine salts.     

城市空气污染分布不均匀特征分析

运用空气质量数据统计分析方法研究了广东省城市间空气污染的分布特征,同时以广州和佛山为例,根据主要工业污染源分布、常规监测站点监测数据及路边空气质量监测实验分析了城市内部空气污染分布特征。研究结果表明,城市间与城市内部的空气污染分布存在不均匀性,空气污染分布不均匀的特点使得少数监测站点的空气质量监测结果难以全面代表整个城市的空气质量。     

Typical atmospheric haze during crop harvest season in northeastern China: A case in the Changchun region

This study presents the mass concentrations of PM_(2.5),O_3,SO_2 and NOxat one urban,one suburban and two rural locations in the Changchun region from September 25 to October 272013. Major chemical components of PM_(2.5)at the four sites were daily sampled and analyzed. Most of daily concentrations of SO_2(7–82 μg/m~3),O_3(27–171 μg/m~3) and NOx(14–213 μg/m~3) were below the limits of the National Ambient Air Quality Standard(NAAQS)in China. However,PM_(2.5)concentrations(143–168 μg/m~3) were 2-fold higher than NAAQS.Higher PM_(2.5)concentrations(~ 150 μg/m~3) were measured during the pre-harvest and harvest at the urban site,while PM_(2.5)concentrations significantly increased from 250 to400 μg m~(-3) at suburban and rural sites with widespread biomass burning. At all sites,PM_(2.5)components were dominated by organic carbon(OC) and followed by soluble component sulfate(SO_4~(2-)),ammonium(NH_4~+) and nitrate(NO_3~-). Compared with rural sites,urban site had a higher mineral contribution and lower potassium(K~+and K) contribution to PM_(2.5).Severe atmospheric haze events that occurred from October 21 to 23 were attributed to strong source emissions(e.g.,biomass burning) and unfavorable air diffusion conditions.Furthermore,coal burning originating from winter heating supply beginning on October 18 increased the atmospheric pollutant emissions. For entire crop harvest period,the Positive Matrix Factorization(PMF) analysis indicated five important emission contributors in the Changchun region,as follows: secondary aerosol(39%),biomass burning(20%),supply heating(18%),soil/road dust(14%) and traffic(9%).     

广西重点城市空气质量预报系统

介绍了应用数值预报和统计预报相结合的集成预报技术建立的广西重点城市空气质量预报系统。指出该系统可根据影响大气污染物的天气系统类型修正预报结果，提高预报的准确率；建立的气象和环保部门的预报会商平台，使气象与环保部门实现了每天异地技术会商、信息资源共享等功能；系统的运行环境要求较低，只需终端用户具有拨号或专线上网或局域网联网功能；系统能用于多城市空气质量预报，对城市环境天气服务中的中小尺度短期(24h-48h)的天气预报也有参考价值。     

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。     

经济发展与环境保护双赢政策初探——从临沂治污事件谈起

新环保法实施以来,环境治理工作取得成效显著。但在一些地区具体环保工作的开展中也出现了一些争议。作为争议焦点事件的临沂治霾工作,引发了地方经济发展与环境保护工作二者关系问题的讨论。实现经济发展与环境保护双赢政策,需要建立环保长效机制,完善法律体系,优化管理机制。更好发挥以环境财税体制和排污权交易为代表的经济杠杆作用,实现污染末端治理与源头治理及产业结构优化调整并举,推进环境微观管理与宏观决策的协调统一,同时做好严格执法与完善立法的最优响应工作。     

Rice and Bricks: Environmental Issues and Mapping of the Unusual Crop Rotation Pattern in the Kathmandu Valley,Nepal

The Kathmandu Valley in Nepal has experienced a very rapid increase in population resulting in considerable land use/land cover change and also a series of environmental problems. One of the results of the population increase is an expansion of brick manufacturing within the Valley because most structures are brick. The brick kilns are intense in several locations of the Valley and have an interesting pattern of using the same lands for bricks during the dry season and then conversion to rice during the wet, summer monsoon months. The increase in brick production has contributed to environmental problems including decreased soil productivity, lowered ground water levels, and particularly air pollution. Brick manufacturing has little, if any, effective regulation. There is a lack of current, accurate data on brick production that could be resolved by remote sensing methods. Controls should be established and more information acquired on the location and impacts of brick production.