Meteorological normalisation and non-parametric smoothing for quality assessment and trend analysis of tropospheric ozone data

Despite extensive efforts to ensure that sampling and installation and maintenance of instruments are as efficient as possible when monitoring air pollution data, there is still an indisputable need for statistical post processing (quality assessment). We examined data on tropospheric ozone and found that meteorological normalisation can reveal (i) errors that have not been eliminated by established procedures for quality assurance and control of collected data, as well as (ii) inaccuracies that may have a detrimental effect on the results of statistical tests for temporal trends. Moreover, we observed that the quality assessment of collected data could be further strengthened by combining meteorological normalisation with non-parametric smoothing techniques for seasonal adjustment and detection of sudden shifts in level. Closer examination of apparent trends in tropospheric ozone records from EMEP (European Monitoring and Evaluation Programme) sites in Finland showed that, even if potential raw data errors were taken into account, there was strong evidence of upward trends during winter and early spring.     

我国土壤中钛,锆,铪和钽的环境背景值及分布规律

在大量土壤样品分析数据的基础上,讨论了钛、锆、铪和钽在不同土类和地区的环境背景值的分布趋势和主要影响因素.     

Phosphate run-off in the Nevezis River (Lithuania)

The long-term (40 yr) observation results of phosphates–phosphorus concentration and its runoff in the Lithuanian fourth largest river Nevezis are analysed. Amounts and peculiarities of background runoff, agricultural runoff, andpoint source pollution from towns were studied for various periods. It has been determined that phosphates enter into the river Nevezis mainly from towns (76.5%), from agricultureonly up to 16%, and the background runoff for 7.5%.Considerable agricultural influence was observed in 1979–1991,when the phosphate runoff increased to 22 kg P km^-2 a^-1 and formed in 1984 33% of the entire runoff. A relation of the phosphates runoff from agriculture, for the entire study period, was obtained with the number of animals in the river's basin. Since 1990, when the number of animals started to decrease, the runoff of phosphates decreased too. Now the phosphatesrunoff from agriculture formed only 2% of the entire runoff. Water in the river Nevezis is heavily polluted with phosphate,according to the EU general classification of the water quality of rivers, although the Lithuanian pollution norms for effluentsdischarging to surface water are not exceeded. Norms for effluents discharging in the rivers from point-sources pollution should be made stricter and the highest permitted ratiobetween the phosphorus load in the river and its waterdischarge should be established.     

Effects of multitasking on operator performance using computational and auditory tasks

This study investigated the effects of multiple cognitive tasks on human performance. Twenty-four students at North Carolina A&;T State University participated in the study. The primary task was auditory signal change perception and the secondary task was a computational task. Results showed that participants' performance in a single task was statistically significantly different from their performance in combined tasks: (a) algebra problems (algebra problem primary and auditory perception secondary); (b) auditory perception tasks (auditory perception primary and algebra problems secondary); and (c) mean false-alarm score in auditory perception (auditory detection primary and algebra problems secondary). Using signal detection theory (SDT), participants' performance measured in terms of sensitivity was calculated as ?0.54 for combined tasks (algebra problems the primary task) and ?0.53 auditory perceptions the primary task. During auditory perception tasks alone, SDT was found to be 2.51. Performance was 83% in a single task compared to 17% when combined tasks.     

Monitoring atmospheric nitrous oxide background concentrations at Zhongshan Station, east Antarctica

At present,continuous observation data for atmospheric nitrous oxide(N_2O) concentrations are still lacking,especially in east Antarctica.In this paper,nitrous oxide background concentrations were measured at Zhongshan Station(69°22′25″S,76°22′14″E),east Antarctica during the period of 2008–2012,and their interannual and seasonal characteristics were analyzed and discussed.The mean N_2O concentration was 321.9 n L/L with the range of 320.5–324.8 n L/L during the five years,and it has been increasing at a rate of 0.29% year-1.Atmospheric N_2O concentrations showed a strong seasonal fluctuation during these five years.The concentrations appeared to follow a downtrend from spring to autumn,and then increased in winter.Generally the highest concentrations occurred in spring.This trend was very similar to that observed at other global observation sites.The overall N_2O concentration at the selected global sites showed an increasing annual trend,and the mean N_2O concentration in the Northern Hemisphere was slightly higher than that in the Southern Hemisphere.Our result could be representative of atmospheric N_2O background levels at the global scale.This study provided valuable data for atmospheric N_2O concentrations in east Antarctica,which is important to study on the relationships between N2 O emissions and climate change.     

成都市黑碳气溶胶污染特征及与气象因子的关系

为系统了解成都市黑碳气溶胶(BC)的污染特征,利用四川省环境监测站提供的成都市人民南路四段2013年9月至2014年7月逐时BC监测数据,对其浓度进行了统计分析。结果表明:1)BC小时平均浓度变化范围较大,介于0.01~57.83μg/m3,浓度中值(5.17μg/m3)小于平均值(7.32μg/m3),即BC小时浓度具有偏态分布特征。2)BC日均浓度变化范围为2~28.2μg/m3,其浓度日变化在四季均呈明显的单谷型,谷值出现在16:00时附近,表现为从凌晨到10:00时变化较平稳,10:00—16:00时浓度急剧下降,16:00到夜间浓度急剧上升;浓度季变化呈现出冬高夏低,春秋平稳的基本特征。3)秋、冬、春、夏四季BC本底浓度值分别为2.49,5.05,2.89,2.43μg/m3。4)BC质量浓度与PM2.5和PM10变化趋势一致,BC浓度相对颗粒物浓度变化较快,在0.01水平上与PM2.5和PM10均呈显著正相关,相关系数分别为0.657、0.638,与温度、降水和风速均呈负相关,相关系数分别为-0.334,-0.338,-0.202。     

A Digital Filter for the State Estimation of Impulsive Noise Under the Existence of a Background Noise and its Experiment in the Work Environment

In the actual work environment, a specific objective noise, like machine and industrial noises, shows impulsive fluctuation form. Furthermore, it often occurs that a specific noise is partially or completely contaminated by background noise. In that case, the fluctuation wave form of the specific noise has to be estimated moment by moment in order to evaluate and/or improve the work environment. In this study, a digital filter for estimating an impulsively fluctuating specific noise is proposed. More specifically, after introducing a generalized time series regressive model of the specific noise, a method for estimating the impulsive noise based on an observation contaminated by the background noise is theoretically derived. Furthermore, the proposed method is applied to the actual task of estimating an industrial impact noise.     

工业企业厂界噪声测量问题探讨

围绕现行的GB12348—2008《工业企业厂界环境噪声排放标准》在厂界噪声测量中测量指标不明确、方法简单、测点位置未细化等问题,通过对增压站、集输站等进行厂界噪声测量,对存在问题进行分析探讨,提出解决这些问题的方法与改进建议。     

阿尔金山保护区地表水部分重金属背景值调查与分析

根据实地考察,采集了阿尔金山保护区主要地表水体的水质样本。受考察期限和水质样本保存要求与期限限制,只对样本中铜、锌、镉等重金属指标进行了检测,分析了各指标与《地表水环境质量标准》中不同标准限值的关系,及其在地理空间上的分布规律。本次考察分析的结果可作为后期水质考察的背景信息,是进一步开展保护区水环境调查和研究的基础。     

背景溶液对纳米氧化铁吸附病毒的影响

以噬菌体X174为病毒替代,通过等温静态批量吸附实验,研究了4种纳米氧化铁(α-Fe2O3、γ-Fe2O3-B、γ-Fe2O3-N、Fe3O4)对病毒在不同背景溶液中的吸附行为及其影响因素.结果表明,在模拟地下水中,4种纳米氧化铁对病毒均具有较高的吸附比例,其中α-Fe2O3对病毒吸附比例最高,在病毒初始浓度比较低(约1E+03PFU.mL-1)时可达100%.经Langmuir和Freundlich吸附等温线方程对上述吸附结果进行拟合表示,纳米氧化铁对病毒的吸附均为有利吸附(favorable adsorption),并可能存在多层吸附,吸附比例均随着病毒初始浓度的增加而减少.纳米氧化铁对病毒的吸附比例随着背景溶液离子强度的增加而降低,表示其吸附行为以电性吸附为主.背景溶液中阴离子存在显著降低了病毒的吸附量,这可能与阴离子竞争病毒吸附位点有关,其中HPO24-比HCO3-表现得更为明显.结果同时显示背景溶液中多价阳离子的存在(比如Ca2+和Mg2+)比单价阳离子(比如Na+和K+)更有利于纳米氧化铁对病毒的吸附.综上可知,纳米氧化铁是一种潜在的病毒净化理想材料,应用时需考虑其环境因素的影响.