烟气排放连续监测技术的发展及应用前景

回顾了烟气排放连续监测系统及其分析技术的发展与应用历程,对直接测量法、抽取测量法和遥感测量法等3种主要连续监测技术的应用情况、技术特点进行了介绍和对比分析。指出烟气连续监测技术有由抽取测量法向直接测量法发展的趋势,进而向遥感测量法发展;分析技术则以光学技术为主导,向全谱分析和线状光谱技术方向发展;测量范围逐渐向低浓度发展,追求更高的准确度和精密度;监测因子更多,除常规烟尘、SO2、NOx外,CO2、H2S、HC l、HF、Hg等物质也将逐步纳入监测范围;技术可靠、系统简洁、操作简便是连续监测技术的发展方向,具有广阔的应用前景。     

重庆市主城区室内氡浓度调查与评价

根据重庆市城市组团式建设特点,采用径迹法对重庆市主城建成区开展室内氡浓度调查。结果表明,各区县室内氡浓度整体水平较低,重庆市主城区室内氡浓度平均值为64.5 Bq/m3,168个采样点均小于国家标准200 Bq/m3;吸入氡及子体对人员产生的年均有效剂量均低于《住房内氡浓度控制标准》和《地下建筑氡及其子体控制标准规定》中规定的室内氡浓度行动水平。     

大气污染影响下凯里植物氮、硫含量分析

对大气污染影响下凯里植物氮、硫质量分数进行测定分析。结果表明:植物的氮质量分数为0.8%～2.8%,平均值为1.5%;硫质量分数为0.4%～1.4%,平均值为0.8%。植物的氮、硫质量分数都高于对照点植物,为对照点植物的1.4倍、1.9倍,表明该区植物已受到了大气污染的影响。不同植物间的氮、硫质量分数差异达到3.5倍和2.5倍。不同类型植物的氮、硫质量分数也存在差异,氮质量分数中:藤本>草本>灌木>乔木,硫质量分数中:藤本>草本>乔木>灌木;落叶植物的氮、硫质量分数>常绿植物的氮、硫质量分数。不同研究点植物的氮、硫质量分数存在差异,均表现为:玻璃厂>火电厂>水泥厂。     

Three-Dimensional Modeling of an Urban Park and Trees by Combined Airborne and Portable On-Ground Scanning LIDAR Remote Sensing

In this study, we confirmed the utility of airborne and portable on-ground scanning light detection and ranging (LIDARs) for three-dimensional visualization of an urban park and quantification of biophysical variables of trees in the park. The digital canopy height model (DCHM) and digital terrain model generated from airborne scanning LIDAR data provided precise images of the ground surface and individual tree canopies. The heights of 166 coniferous and broadleaf trees of 11 species in the park were estimated from the DCHM images with slight underestimation (mean error = −0.14 m, RMSE = 0.30 m). Portable on-ground scanning LIDAR provided images of individual trees with detailed features. Tree height and trunk diameter were estimated to be within 0.31 m and 1 cm, respectively, from the on-ground LIDAR images. We combined airborne and on-ground LIDAR images to overcome blind regions and created a complete three-dimensional model of three standing trees. The model allowed not only visual assessment from all viewpoints but also quantitative estimation of canopy volume, trunk volume, and canopy cross-sectional area.     

文物保存环境调湿净化一体化装置的效果评价

相对湿度是文物保存环境的一个极其重要的参数,NOx耦合水分对于文物的破坏性很大。在前期开发的空气净化器的基础上,研究了空气净化和湿度调节系统集成技术和参数,考察了空气净化器各单元对NOx的去除率,并评价了流量和相对湿度的影响,结果发现不同净化单元的设置合理有效。相对湿度低的情况下,氮氧化物去除率较高,达到96%以上,但在相对湿度较高的情况下则降低为66%。将空气净化器串联了调湿装置后,发现调湿器调湿效果显著,在各种环境湿度的情况下能有效的保持展柜的湿度。但在降湿效果上有待提高,调湿器的结构以及参数需要进一步优化。     

Estimate of the uncertainty in measurement for the determination of mercury in seafood by TDA AAS

An approach for the estimate of the uncertainty in measurement considering the individual sources related to the different steps of the method under evaluation as well as the uncertainties estimated from the validation data for the determination of mercury in seafood by using thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) is proposed. The considered method has been fully optimized and validated in an official laboratory of the Ministry of Agriculture, Livestock and Food Supply of Brazil, in order to comply with national and international food regulations and quality assurance. The referred method has been accredited under the ISO/IEC 17025 norm since 2010. The approach of the present work in order to reach the aim of estimating of the uncertainty in measurement was based on six sources of uncertainty for mercury determination in seafood by TDA AAS, following the validation process, which were: Linear least square regression, Repeatability, Intermediate precision, Correction factor of the analytical curve, Sample mass, and Standard reference solution. Those that most influenced the uncertainty in measurement were sample weight, repeatability, intermediate precision and calibration curve. The obtained result for the estimate of uncertainty in measurement in the present work reached a value of 13.39%, which complies with the European Regulation EC 836/2011. This figure represents a very realistic estimate of the routine conditions, since it fairly encompasses the dispersion obtained from the value attributed to the sample and the value measured by the laboratory analysts. From this outcome, it is possible to infer that the validation data (based on calibration curve, recovery and precision), together with the variation on sample mass, can offer a proper estimate of uncertainty in measurement.     

Does Divergence of Nutrient Load Measurements Matter for Successful Mitigation of Marine Eutrophication?

Successful implementation of an international nutrient abatement agreement, such as the Baltic Sea Action Plan (BSAP), requires consistent understanding of the baseline nutrient loads, and a perception of acceptable costs and fairness in targeted reductions of these base line loads. This article presents a general framework for identifying the implications of divergence between different nutrient load quantification approaches, with regard to both cost and fairness criteria outcomes, for the international agreement to decrease nutrient loads into the Baltic Sea as presented in the BSAP. The results indicate that even relatively small divergence in the nutrient load quantification translates into relatively large differences in abatement cost for different Baltic Sea countries. A robust result, irrespective of differences in nutrient load assessments, is a conflict between abatement cost effectiveness and fairness, with relatively poor countries facing heavy abatement cost burdens for cost-effective international load abatement.     

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.     

The influence of neighborhood traffic density on the respiratory health of elementary schoolchildren

Background

Several studies have found that living near major roadways is associated with an increase in respiratory illness but few studies have measured the volume and type of traffic.

Objective

We investigated the relation between traffic volume and respiratory health of 2328 children 9 to 11 years old in the city of Windsor, Canada.

Methods

We identified the roadways within a 200 meter radius of the child's neighborhood using the latitude and longitude of the residential postal code. Traffic exposure was defined as the sum of the annual volume of vehicles on all of these roadways. Volume was calculated using sensors to detect passing vehicles (simple traffic counts), and by counts and direction of traffic at intersections (turning movement counts). Ventilatory lung function was measured by spirometry and airway inflammation by exhaled nitric oxide (eNO).

Results

The odds ratio between an interquartile increase in truck turning movement counts and chest congestion was 1.20 (1.06-1.35). The percentage of predicted FVC declined 0.68%, (95% CI 1.32, 0.03) for an interquartile increase in simple traffic counts (33,787 vehicles daily). Among those with self-reported asthma, effect sizes were larger. Percentage predicted FEV₁ declined 1.84% (95% CI 0.07, 3.61) associated with an interquartile range increase in turning movement counts. No statistically significant change was detected between traffic measures and exhaled nitric oxide.

Conclusions

Our findings provide further support for the hypothesis that neighborhood exposure to traffic-related air pollution increases respiratory symptoms and reduces ventilatory function in children, especially those with self-reported asthma.     

高低温试验能力验证常见不满意原因分析

测量审核和实验室间比对是能力验证计划的有效补充形式,是实验室或者检查机构用于实验室质量控制及申请CNAS认可的重要手段。本文随机抽取2010年～2012年低温试验测量审核与高温试验实验室间比对结果为不满意的报告各8份作为样本,进行原因分析,并给出技术建议,旨在让参加实验室在以后的相关试验中能规避常见问题,提高测试能力。