Deciphering urban traffic impacts on air quality by deep learning and emission inventory

Air pollution is a major obstacle to future sustainability, and traffic pollution has become a large drag on the sustainable developments of future metropolises. Here, combined with the large volume of real-time monitoring data, we propose a deep learning model, iDeepAir, to predict surface-level PM_2.5 concentration in Shanghai megacity and link with MEIC emission inventory creatively to decipher urban traffic impacts on air quality. Our model exhibits high-fidelity in reproducing pollutant concentrations and reduces the MAE from 25.355 µg/m³ to 12.283 µg/m³ compared with other models. And identifies the ranking of major factors, local meteorological conditions have become a nonnegligible factor. Layer-wise relevance propagation (LRP) is used here to enhance the interpretability of the model and we visualize and analyze the reasons for the different correlation between traffic density and PM_2.5 concentration in various regions of Shanghai. Meanwhile, As the strict and effective industrial emission reduction measurements implementing in China, the contribution of urban traffic to PM_2.5 formation calculated by combining MEIC emission inventory and LRP is gradually increasing from 18.03% in 2011 to 24.37% in 2017 in Shanghai, and the impact of traffic emissions would be ever-prominent in 2030 according to our prediction. We also infer that the promotion of vehicular electrification would achieve further alleviation of PM_2.5 about 8.45% by 2030 gradually. These insights are of great significance to provide the decision-making basis for accurate and high-efficient traffic management and urban pollution control, and eventually benefit people's lives and high-quality sustainable developments of cities.     

Design and prediction for highly efficient SO2 capture from flue gas by imidazolium ionic liquids

An efficient method for prediction in the capture of SO2 from flue gas by imidazolium ionic liquids was reported, where the concentration of SO2 is 2000 ppm. On the basis of quantitative calculations through a combination of Langmuir simulation, theoretical calculation and quantum chemical method, SO2 absorption and desorption performance from flue gas by twelve kinds of imidazolium ionic liquids with different anions were designed and predicted. Then, among them, five kinds of imidazolium ionic liquids were chosen and prepared to investigate their behavior of SO2 absorption capacity, desorption residue, and available absorption capacity. The results indicated that the experimental values were in good agreement with the predicted values. Thus, an ideal ionic liquid [Emim][Tetz] was obtained through the predictive method for the capture of SO2 of 2000 ppm, which showed high available absorption capacity of 0.24 g SO2 per g ionic liquid and excellent reversibility.     

嘧草醚在水稻中的残留消解动态及膳食风险评估

为了评价嘧草醚在水稻生长过程中使用的安全性,于2018—2019年分别在佳木斯、济宁、南昌、宁波4地进行了为期2年的田间试验,研究了嘧草醚在田水、土壤、稻株中的消解动态及稻米、稻壳、稻杆中的最终残留.结果表明：嘧草醚在田水、土壤及稻株中的消解规律均符合一级动力学模型,在4地田水中的消解半衰期（t_1/2）为1.07~3.48 d,土壤中的消解半衰期（t_1/2）为3.14~5.42 d,稻株中的消解半衰期（t_1/2）为4.47~8.08 d.通过对消解半衰期与土壤性质和气候条件的线性回归分析可得,嘧草醚在不同基质中的消解速率均与土壤有机质含量和平均气温呈显著相关.施用1.5倍或2倍推荐使用剂量的嘧草醚后（90或120 g·hm^-2）,收获的稻米籽实中检测出嘧草醚的残留量均未超过日本和韩国规定的最大残留限量（MRL）值（0.05 mg·kg^-1）.通过计算得出每人每天从稻米中所摄入的嘧草醚为0.0037 mg,其风险商值（RQ）为0.0028,处于安全水平.     

Exploring the impact of new particle formation events on PM2.5 pollution during winter in the Yangtze River Delta, China

New particle formation（NPF） events are an increasingly interesting topic in air quality and climate science. In this study, the particle number size distributions, and the frequency of NPF events over Hefei were investigated from November 2018 to February 2019. The proportions of the nucleation mode, Aitken mode, and accumulation mode were 24.59%,53.10%, and 22.30%, respectively, which indicates the presence of abundant ultrafine particles in Hefei. Forty-six NPF events occurred during the obser...     

石化企业应急能力评估方法与应用

在系统分析目前应急能力评估研究存在问题的基础上,提出了石化企业应急能力评估方法,包括应急准备评估和重大事故情景应对能力评估。应急准备评估为定量评估,设置10个一级指标、26个二级指标、48个三级指标,每个指标依据权重赋值,按照得分情况分为5个等级。重大事故情景应对能力评估为定性评估,基于"情景-应对"的方式、从10个应急功能对现有应急能力进行分析,评估结果分为4个等级。提出的方法在某天然气生产企业进行了应用,结果表明方法科学、合理,可以帮助企业了解现有应急能力存在的不足。     

污染场地河道底泥浸出液对斑马鱼胚胎的毒性效应

为了评价某污染场地河道底泥对水生生物的毒性效应及其潜在生态风险,以斑马鱼(Brachydanio rerio)为受试生物,进行了河道底泥浸出液对斑马鱼胚胎的发育毒性实验。结果表明,5种底泥浸出液(A1、A2、A3、A4、A5)对斑马鱼胚胎的发育均有毒性效应,浸出液对斑马鱼胚胎的死亡率存在一定的剂量-效应关系,随着浸出液体积分数的增加,死亡率显著上升。浸出液对胚胎孵化抑制作用明显,随着浸出液体积分数的增加,孵化率显著下降。且能引起斑马鱼胚胎多种中毒症状,如水肿,鱼体弯曲,发育不全等异常现象,表明该段河道底泥存在潜在的生态风险。因此,在后期的污染场地河道整治中,需对河道底泥进行挖掘清理和无害化处理。     

Activated carbons and amine-modified materials for carbon dioxide capture — a review

Rapidly increasing concentration of CO₂ in the atmosphere has drawn more and more attention in recent years, and adsorption has been considered as an effective technology for CO₂ capture from the anthropogenic sources. In this paper, the attractive adsorbents including activated carbons and amine-modified materials were mainly reviewed and discussed with particular attention on progress in the adsorbent preparation and CO₂ adsorption capacity. Carbon materials can be prepared from different precursors including fossil fuels, biomass and resins using the carbonization-activation or only activation process, and activated carbons prepared by KOH activation with high CO₂ adsorbed amount were reviewed in the preparation, adsorption capacity as well as the relationship between the pore characteristics and CO₂ adsorption. For the amine-modified materials, the physical impregnation and chemical graft of polyethylenimine (PEI) on the different porous materials were introduced in terms of preparation method and adsorption performance as well as their advantages and disadvantages for CO₂ adsorption. In the last section, the issues and prospect of solid adsorbents for CO₂ adsorption were summarized, and it is expected that this review will be helpful for the fundamental studies and industrial applications of activated carbons and amine-modified adsorbents for CO₂ capture.     

天地一体化遥感监测大气污染技术进展

天地一体化遥感监测技术通过地基和卫星融合互补,成为研究大气污染来源、传输和影响的重要方法.但目前国外主导的地基和卫星遥感算法不适应国内复杂大气环境,其数据可靠性尚需验证.为进一步推动国内大气研究自主性,厘清天地一体化遥感监测技术发展现状,对相应的平台建设、算法研发及应用实例进行介绍.结果表明:①可通过地基观测网络实时连续监测大气污染物的浓度（柱总量）/廓线信息,目前国内组建并运行了CNEMC空气质量监测网络和USTC地基遥感网络.②可通过紫外-可见波段卫星载荷获取全球/区域尺度大气污染物的浓度（柱总量）/廓线产品,GF-5搭载的EMI填补了国内该类载荷的空白,基于DOAS（BOAS）的柱总量反演算法、基于OE的垂直廓线反演算法是当下国际主流业务算法.③天地一体化遥感监测技术以高精度、广覆盖、准定位的优势得到快速发展,可为亟需解决的大气污染治理成效评估、作用机理研究、区域传输测算及精准溯源等难题提供技术支持.研究显示,天地一体化遥感监测技术需以应用化和业务化为导向,加快观测平台硬件建设,加强相关反演算法研发,深入融合多平台数据,全面推进大气遥感监测技术的立体化和系统化发展.      

开关柜套管屏蔽线安装方法的分析

在进行35kV开关柜投运前的带电检测中,发现某开关柜特高频信号异常,暂态地电压、超声波幅值与背景值比较,超过带电检测规程要求,随后对开关柜进行停电解体检查,发现套管屏蔽线过长,触碰到套管内壁,导致在进行工频交流耐压试验中,击穿空气,造成绝缘放电。 最后提出了相应的处理措施。     

土壤酸化空间信息模型构建及其在贵州龙里实验区的应用

依托遥感和地理信息系统理论和技术,基于TM数据、气象资料和化学实测数据,将基于能量循环的土壤水平衡模型和基于物质循环的土壤酸化模型相耦合,构建了土壤酸化空间信息模型,解决了土壤化学性质从点尺度到空间尺度的扩展.并以季节尺度模拟了酸沉降对土壤化学性质的影响,分析了贵州省龙里县2007年不同植被类型覆盖土壤受酸沉降影响的定量变化特征,结果表明,①从空间角度来说,在同一季节内,不同植被覆盖类型土壤水的pH值和土壤盐基饱和度的大小关系为:草地混交林灌丛针叶林;②从时间角度来说,土壤水盐基浓度主要与土壤水含量呈负相关性,即浓度随着土壤水含量的增加而降低.不同季节相同指标的浓度由高到低为:春季秋季冬季夏季;③不同植被覆盖类型土壤受相同酸沉降的影响不同,受酸雨影响由大到小为:针叶林灌丛混交林草地.