中国の大都市における硫酸とアミンの新粒子の形成
Lei Yao1, Olga Garmash2, Federico Bianchi2,3
1Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
まとめ
上海の大気中の新粒子の形成は 硫酸・二メチラミン・水の核化によって引き起こされる この過程で最初のクラスターが形成され,有機種は後に都市環境で粒子の成長に貢献します.
科学分野:
- 大気化学
- 環境科学
- エアロゾール科学
背景:
- 大気中の新粒子の形成 (NPF) は,環境要因の影響を受ける重要なグローバルなプロセスです.
- NPFは通常,高硫酸濃度と低既存のエアロゾール負荷を効率的な粒子生成のために必要とします.
研究 の 目的:
- 上海のNPFを分子レベルで調査し,前駆体蒸気と初期クラスタを特定します.
- メガシティ環境でNPFを駆動する主要な化学物種とプロセスを決定します.
主な方法:
- 前駆体蒸気 (硫酸) と初期クラスターの分子レベルでの観察.
- 粒子の形成と成長をモデル化するためのクラスター運動シミュレーション.
- 硫酸ジマーとH2SO4-DMAクラスターを含むNPFマーカーの分析
主要な成果:
- 硫酸二メチラミン水核化マーカーと相関する高いNPF率
- 観測された硫酸濃度は,高濃縮シンクにもかかわらず, ~ 3 nm の初期粒子の成長をサポートしました.
- その後の粒子の成長は有機種の凝縮に起因した.
結論:
- 硫酸-ジメチラミン-水核化は,上海におけるNPFにとって重要な経路である.
- 都市部では有機生物が 新たに形成された粒子の成長に 重要な役割を果たしています
- 都市空気の質,気候影響,中国における二次粒子の緩和に関する政策の策定に役立つ.
関連する概念動画
The Sulfur Cycle
52.0K
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
52.0K
Aldehydes and Ketones with Amines: Imine Formation Mechanism
8.5K
Imine formation involves the addition of carbonyl compounds to a primary amine. It begins with the generation of carbinolamine through a series of steps involving an initial nucleophilic attack and then several proton transfer reactions. The second part includes the elimination of water, as a leaving group, to give the imine.
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
Imines are formed under mildly acidic conditions. A pH of 4.5 is ideal for the reaction.
If the pH is low or the solution is too acidic, the reaction slows down in the...
8.5K
Aldehydes and Ketones with Amines: Enamine Formation Mechanism
7.7K
Enamine formation involves the addition of carbonyl compounds to a secondary amine through a series of reactions. The mechanism begins with the generation of carbinolamine, a nucleophilic attack followed by several proton transfer reactions. The hydroxyl group of the carbinolamine is converted into water to make a better leaving group that can push the reaction forward by eliminating a water molecule. In enamine formation, the last step involves the abstraction of a proton from the α carbon to...
7.7K
Precipitate Formation and Particle Size Control
6.9K
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
6.9K
Amino acids
105.7K
Amino acids are the monomers that comprise proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom. Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. There are 20 common amino acids present in proteins, each with a different R group. Variation in the amino acid sequence is responsible for...
105.7K
Sulfur Assimilation
358
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
358


