Heterogeneous uptake of NO2 on soils under variable temperature and relative humidity conditions

Heterogeneous reactions of nitrogen dioxide (NO₂) on soils collected from Dalian (S1) and Changsha (S2) were investigated over the relative humidity (RH) range of 5%-80% and temperature range of 278-328 K using a horizontal coated-wall flow tube. The initial uptake coefficients of NO₂ on S2 exhibited a decreasing trend from (10 ± 1.3) × 10^-8 to (3.1 ± 0.5) × 10^-8 with the relative humidity increasing from 5% to 80%. In the temperature effect studies, the initial uptake coefficients of S1 and S2 decreased from (10 ± 1.2) × 10^-8 to (3.8 ± 0.5) × 10^-8 and from (16 ± 2.2) × 10^-8 to (3.8 ± 0.4) × 10^-8 when temperature increased from 278 to 288 K for S1 and from 278 to 308 K for S2, respectively. As the temperature continued to increase, the initial uptake coefficients of S1 and S2 returned to (7.9 ± 1.1) × 10^-8 and (20 ± 3.1) × 10^-8 at 313 and 328 K, respectively. This study shows that relative humidity could influence the uptake kinetics of NO₂ on soil and temperature would impact the heterogeneous chemistry of NO₂.     

天津市颗粒物散射消光特征及化学组分贡献研究

为研究天津大气颗粒物光学特征及不同化学成分贡献水平,对颗粒物散射系数进行了在线观测,同时对全年1,4,7,10 4个典型月份进行PM2.5采样,并分析其化学成分.观测发现,天津市散射消光系数表现为秋、冬季高,春、夏季低,冬季PM2.5的干散射效率最高,为5.18m2/g.当风速大于3m/s时,对污染物的清除扩散作用较为明显,散射系数较低;相对湿度较高时,其对散射系数的增长作用显著.多元线性回归分析结果表明,天津市细颗粒中有机碳和硫酸盐是影响天津市能见度的主要组分.根据IMPROVE法核算化学组分对散射消光的贡献,得出有机物的贡献最大,为38.51%.     

防静电服带电电荷量测试方法探讨

通过对现行防静电服带电电荷量检测相关标准对比分析,发现存在一些操作难点,在实验的基础上,提出了改进建议。试验表明,宜选用尺寸略大、配有腈纶摩擦标准布的自动式滚筒摩擦机作为摩擦装置,选择自动式试验方法。控制试验中试样的耐洗涤程序,洗涤次数为100次,测试环境温湿度据不同行业要求选择,温度的偏差≤±1℃。     

调湿涂层性能试验研究

湿度是载人航天器舱内环境质量的重要参数之一。调湿涂层是一项新的技术,文中对调湿涂层的吸湿性能进行了试验验证。试验结果表明,研制的调湿涂料可以在40 min内使密闭环境的相对湿度由92.5%下降到79.5%,在13 h内可由92.5%下降到66%,试验结果表明研制的调湿涂层具有良好的吸湿性能。     

上海市青浦区PM_(10)污染与气象要素的关系

利用2006年-2010年上海市青浦区PM10和同期地面气象要素的监测资料,定量分析PM10的季节变化规律以及PM10与降雨量、大气湿度和风速之间的关系。分析结果表明:PM10浓度在夏季处于低值,冬季处于高值;5 mm/d以上的降雨对PM10有显著的清除作用,且春夏季降雨的清除作用大于秋冬季节。PM10浓度与大气湿度基本呈负相关关系。风速在一定范围内有利于PM10的扩散但不至造成扬尘,春季的适宜风速是1.5～3.5m/s,冬季的适宜风速是1.5～2.5 m/s。     

北方城市冬季室内环境空气中正负离子浓度分布特征

使用ITC201A空气负离子测量仪测定了中国北方地区冬季室内正负离子浓度水平,按照空气质量评价标准评价了室内空气质量等级,研究了室内空间的正负离子浓度日变化,讨论了正负离子浓度与室内温度湿度之间的相关关系。研究结果表明:①中国东北地区冬季室内正负离子浓度水平极低,负离子平均为浓度46.9个/cm3,正离子平均浓度为52.0个/cm3,室内空气质量等级为中度和重度污染。②室内正负离子平均浓度在中午时刻均达到全天中的峰值阶段,全天中大部分时间正离子浓度高于负离子浓度;在室内人群活动和环境因子等因素复杂的影响下,正负离子平均浓度此消彼长的发生波动变化。③研究期间室内正负离子浓度变化与空气温度和湿度间未发现显著线性相关关系,环境因子的综合作用影响着室内正负离子的浓度变化水平。     

气候试验箱内部条件不确定度计算(上)

提供了对温度和湿度气候试验箱内部环境条件进行不确定度分析的方法。首先介绍了测量的不确定度概念,然后讨论容差的意义。考虑到湿度和温度测量是采用确定和合成不确定度。结合校准空载试验箱和有负载试验箱的条件测量的案例。最后,逐条整理成为范本用于分析结果以给出规范的不确定度评估依据。     

气候(温度/湿度)和力学动态(振动/冲击)组合试验

在汽车、轨道交通和空间领域都存在温度、湿度和振动或冲击的组合环境。通过实验室内受控地在参量范围内模拟环境下暴露样品进行评估。用严酷的环境参量强化试验,通常可在相对较短的时间内获得有效的结果。     

A Study on the Environmental Degradation of Pesticides Azinphos Methyl and Parathion Methyl

Abstract

The effect of environmental parameters (temperature and relative humidity) on the degradation rate of azinphos methyl and parathion methyl was studied. Proprietary emulsifiable concentrates were diluted and added to each of 90 glass Petri dishes for each pesticide and were left overnight to dry. Petri dishes were placed in 18 air-tight containers (9 for each pesticide) in which were created environments with relative humidity (RH) of 60, 82, and 96%. The containers were stored at 0, 20, and 40°C. From the experimental results best fit curves, kinetic equations, rate constants, and half-lives were calculated. Half-lives of azinphos methyl for the RH studied were, from 124 to 267 days at 0°C, from 89 to 231 days at 20°C, and from 25 to 71 days at 40°C. Corresponding half-lives for parathion methyl were from 48 to 57 days at 0°C, from 9.2 to 10.5 days at 20°C and from 1.3 to 1.5 days at 40°C. The results were correlated with relevant results from the decomposition of the same or similar pesticides on apples both, on the trees and during refrigerated storage. These correlations are suggesting that biological factors strongly affected the decomposition rate of azinphos methyl. On the contrary the decomposition of parathion methyl was mainly affected by environmental rather than biological factors.     

秦皇岛探测环境变化对气象要素的影响

为分析秦皇岛地面气象探测环境变化对气象要素的影响，采用距平百分率和线性倾向估计及趋势系数等方法，对秦皇岛气象站（54449）新、旧站址搬迁前后1989—1998、1999—2008年各10年，与没有迁站的昌黎站做同期资料比较，结果表明：秦皇岛探测环境变化对气象要素有显著影响：年平均气温、年极端气温较迁站前显著下降，相对湿度增大，日照时数明显减少，雾日增多。指出气象要素变化除具有随时间变化的共同差异外，主要受探测环境变化的影响。