Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(6)
Published: Dec. 12, 2023
The reactions of glyoxal (CHO)
Language: Английский
Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(30), P. 11163 - 11172
Published: July 5, 2023
Optical characteristics and molecular compositions of brown carbon (BrC) were investigated during winter 2019 at a rural site China with focus on nitro-aromatic compounds (NACs) imidazoles (IMs). The abundance gaseous nitrophenols relative to CO the campaign maximized noontime, being similar O3, while particulate NACs haze periods strongly correlated toluene NO2, suggesting that in region are largely formed from gas-phase photooxidation. Strong correlations IMs dry mass ratio EC/PM2.5 concentration levoglucosan observed, indicating events derived biomass burning emissions. However, an increase increasing aerosol liquid water content pH was observed humid events, along much lower abundances K+ PM2.5, mostly aqueous reactions periods. These exponentially increased NH3 owing reaction carbonyls free ammonia. Our findings for first time revealed enhancing effect ammonia BrC formation China, especially
Language: Английский
Citations
45
Advances in Atmospheric Sciences, Journal Year: 2023, Volume and Issue: 40(8), P. 1339 - 1361
Published: April 28, 2023
Atmospheric chemistry research has been growing rapidly in China the last 25 years since concept of "air pollution complex" was first proposed by Professor Xiaoyan TANG 1997. For papers published 2021 on air (only included Web Science Core Collection database were considered), more than 24 000 authored or co-authored scientists working China. In this paper, we review a limited number representative and significant studies atmospheric few years, including (1) sources emission inventories, (2) chemical processes, (3) interactions with meteorology, weather climate, (4) between biosphere atmosphere, (5) data assimilation. The intention not to provide complete all progress made but rather serve as starting point for learning about advances reviewed paper have enabled theoretical framework complex be established, provided robust scientific support highly successful control policies China, created great opportunities education, training, career development many graduate students young scientists. This further highlights that developing low-income countries are heavily affected can benefit from these advances, whilst at same time acknowledging challenges still remain hopefully addressed over next decades.
Language: Английский
Citations
39
Atmospheric chemistry and physics, Journal Year: 2021, Volume and Issue: 21(23), P. 17759 - 17773
Published: Dec. 6, 2021
Abstract. NH3 is the most important alkaline gas in atmosphere and one of key species affecting behaviors atmospheric aerosols. However, impact on secondary organic aerosol (SOA) formation remains poorly understood, especially dynamic evolution chemical compositions SOA process. In this study, a series chamber experiments were performed to probe individual common effects NOx toluene through OH photooxidation. The characterized using Aerodyne high-resolution time-of-flight mass spectrometer (AMS). yield increased from 28.1 % absence 34.7 presence but decreased 19.5 NOx. highest 42.7 lowest carbon oxidation state (OSC) occurred both NOx, indicating that higher-volatility products formed could partition into particle phase when was added. This resulted synergetic effect co-existed. heterogeneous reaction main pathway by which participated photooxidation also observed optical absorption. A peak at 280 nm, characteristic organonitrogen imidazole compounds, NH3, its intensity added chamber. work improves our understanding how synergistic interactions between influence offers new insights mitigating haze pollution.
Language: Английский
Citations
43
Environmental Science & Technology Letters, Journal Year: 2022, Volume and Issue: 9(4), P. 265 - 271
Published: March 23, 2022
As a potential fraction of brown carbon, particulate imidazole compounds may initiate photosensitive reactions and have substantial radiative effects. However, our knowledge the atmospheric processing is still in its nascent stage. On basis single-particle aerosol mass spectrometer measurement, mixing state imidazole-containing particles high-time-resolved variations were investigated Qingdao, China, November December 2019. Five (methylimidazole, ethylimidazole, dimethylimidazole, imidazole-2-carboxaldehyde, 2,2′-biimidazole) identified, overall accounting for ∼10% all detected particles. They are tightly correlated internally mixed with enhanced carbonyls, amines, ammonium, supporting their secondary formation from these precursors. The number exhibited predominant diurnal variations, especially on sunny days. A sharp decrease morning to noon most likely attributed photochemical degradation. This also confirmed by reverse correlation (r = −0.77; p < 0.01) indicators (temperature O3) laboratory experiment exposure sunlight. Multiple linear regression random forest analysis further support hypothesis, precursors (i.e., carbonyls amines/ammonium) O3 being important factors (∼70%) regulating compounds.
Language: Английский
Citations
30
TrAC Trends in Analytical Chemistry, Journal Year: 2024, Volume and Issue: 172, P. 117614 - 117614
Published: Feb. 21, 2024
Language: Английский
Citations
7
ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(5), P. 426 - 437
Published: April 9, 2024
Light-absorbing secondary organic aerosols (SOAs), also known as brown carbon (BrC), are major components of wildfire smoke that can have a significant impact on the climate system; however, how environmental factors such relative humidity (RH) influence their formation is not fully understood, especially for heterocyclic precursors. We conducted chamber experiments to investigate BrC from nighttime oxidation furan and pyrrole, two primary precursors in wildfires, presence pre-existing particles at RH < 20% ∼ 50%. Our findings revealed increasing significantly affected size distribution dynamics both SOAs, with pyrrole SOA showing stronger potential generate ultrafine via intensive nucleation processes. Higher led increased mass fractions oxygenated compounds suggesting enhanced gas-phase and/or multiphase under humid conditions. Moreover, higher reduced absorption coefficients BrC, contrasting those homocyclic precursors, due non-absorbing high-molecular-weight decreasing molecular chromophores. Overall, our demonstrate unique dependence which may critically modulate radiative effects change.
Language: Английский
Citations
7
Journal of Environmental Sciences, Journal Year: 2024, Volume and Issue: 151, P. 310 - 330
Published: April 14, 2024
Language: Английский
Citations
5
Atmospheric Environment, Journal Year: 2024, Volume and Issue: 329, P. 120536 - 120536
Published: April 26, 2024
Language: Английский
Citations
5
ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(7), P. 617 - 627
Published: May 9, 2024
Imidazole produced by the interaction of glyoxal with nitrogen-containing chemicals in atmospheric particles can yield secondary organic aerosol (SOA) due to oxidation. However, knowledge about aqueous phase reaction mechanism imidazole formation and its oxidation is still very limited. This work investigated aqueous-phase oxidative degradation reactions hydroxyl radical (•OH), nitrate (NO3•), ozone (O3). Results showed that involves many dehydration favorable under moderate- or low-RH conditions. The calculated lifetimes 14.05, 0.27, 3.45 h for •OH, NO3•, O3, respectively, suggest efficient tropospheric Formamide oxamide are main products presence O2, nitro-imidazoles also be formed NO2. optical properties evolve significantly, attributable nitro-imidazoles, resulting a red shift absorption peak UVA UVB region.
Language: Английский
Citations
4
Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(12), P. 6987 - 6999
Published: June 18, 2024
Abstract. While aqueous-phase processing is known to contribute the formation of nitrogen-containing organic compounds (NOCs), specific pathways involved remain poorly understood. In this study, we aimed characterize NOCs present in both pre-fog aerosols and fog water collected at a suburban site northern China. Fourier-transform ion cyclotron resonance mass spectrometry was utilized analyze molecular composition negative positive modes electrospray ionization (ESI− ESI+). samples, constituted significant portion, accounting for over 60 % all assigned formulas ESI− more than 80 ESI+. By comparing originating from biomass burning, coal combustion, vehicle emissions, identified that 72.3 were attributed primary anthropogenic sources (pNOCs), while remaining categorized as secondary formed within (saNOCs). Unique found classified (sfNOCs). Through comprehensive “precursor–product pair” screening involving 39 reaction pathways, observed nitration reaction, amine pathway, intramolecular N-heterocycle pathway NH3 addition reactions contributed 43.6 %, 22.1 11.6 saNOCs, respectively. contrast, these 26.8 28.4 29.7 sfNOCs, This disparity likely influenced by diverse precursors, aqueous acidity, gas-phase species partitioning. Correspondingly, saNOCs contain higher abundance carbohydrate-like highly oxygenated with two nitrogen atoms compared pNOCs. Conversely, sfNOCs exhibited content lipid-like fewer oxygen atoms. These results underscore distinct processes contributing diversity water, which may lead their different climate effects.
Language: Английский
Citations
4