Self-Catalytic Reaction of SO₃ and NH₃ To Produce Sulfamic Acid and Its Implication to Atmospheric Particle Formation

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(35), P. 11020 - 11028

Published: Aug. 8, 2018

Sulfur trioxide (SO3) is one of the most active chemical species in atmosphere, and its atmospheric fate has profound implications to air quality human health. The dominant gas-phase loss pathway for SO3 generally believed be reaction with water molecules, resulting sulfuric acid. latter viewed as a critical component new particle formation (NPF). Herein, competitive presence abundant ammonia (NH3) identified. Specifically, between NH3, which produces sulfamic acid, can self-catalyzed by reactant (NH3). In dry heavily polluted areas relatively high concentrations effective rate constant bimolecular SO3-NH3 sufficiently fast through this become conventional water. Furthermore, study shows that final product reaction, namely, enhance fastest possible NPF from acid dimethylamine (DMA) about factor 2. An alternative source stabilizer acid-base clustering atmosphere suggested, mechanism potential improve modeling highly regions.

Language: Английский

---

Enhanced growth rate of atmospheric particles from sulfuric acid

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(12), P. 7359 - 7372

Published: June 25, 2020

Abstract. In the present-day atmosphere, sulfuric acid is most important vapour for aerosol particle formation and initial growth. However, growth rates of nanoparticles (<10 nm) from remain poorly measured. Therefore, effect stabilizing bases, contribution ions impact attractive forces on molecular collisions are under debate. Here, we present precise rate measurements uncharged particles 1.8 to 10 nm, performed atmospheric conditions in CERN (European Organization Nuclear Research) CLOUD chamber. Our results show that evaporation above 2 nm negligible, proceeds kinetically even at low ammonia concentrations. The experimental exceed hard-sphere kinetic limit condensation acid. We demonstrate this van der Waals between molecules disentangle it charge–dipole interactions. magnitude enhancement depends assumed hydration collision kinetics but increasingly smaller sizes, resulting a steep rise observed with decreasing size. Including global model, find enhanced increases predicted number concentrations upper free troposphere by more than 50 %.

Language: Английский

---

On the connotation, challenge and significance of China's “energy independence” strategy

Petroleum Exploration and Development, Journal Year: 2020, Volume and Issue: 47(2), P. 449 - 462

Published: April 1, 2020

The world's energy is in the "third major transformation period" from fossil to new energy, and all countries world have formulated development strategies. Through advanced deployment, United States about achieve "energy independence" relying on "unconventional oil gas revolution". China's faced with four challenges: (1) population base economic scale determine "totally huge amount" of consumption; (2) "coal rich but insufficient" resource structure determines "unclean" consuming structure; (3) increasing dependence imported "unsafe" supply; (4) unconventional endowment makes it impossible independence by copying American model. From perspective trend unique situation we put forward a "three-step" strategy for China independence": 2020 2035, supply security" will be addressed "cleaning coal, stabilizing production vigorously developing alternative energy"; 2035 2050, vision "production realized "domestic overseas mining rights"; 2050 2100, "intelligent energy" help realize independence". two important signs are that domestic accounts more than 90% consumption clean 70%, security realizes "independence self-control" "long-term security". strategic significance ensure national security, drive relevant industries, management reform, implement environmental protection goal zero carbon emissions. mission, might fulfilled future growth state's power, even when does not catch up consumption. Perhaps technological revolution exceed expectations, dream eventually come true.

Language: Английский

---

How well can we predict cluster fragmentation inside a mass spectrometer?

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(42), P. 5946 - 5949

Published: Jan. 1, 2019

We measured the fragmentation of clusters inside an MS and we developed a model to describe predict their fragmentation.

Language: Английский

---

On the Relationship Between Aerosol and Boundary Layer Height in Summer in China Under Different Thermodynamic Conditions

Earth and Space Science, Journal Year: 2019, Volume and Issue: 6(5), P. 887 - 901

Published: April 30, 2019

Abstract The observed relationships between boundary layer height (BLH) and PM 2.5 on a national scale remain unclear due to the dearth of observations. Here we investigated this relationship from unique perspective thermodynamic stability in planetary (PBL), using summertime (June–August) soundings China for period 2014 2017. For all three times (0800, 1400, 2000 Beijing time [BJT]), positive (negative) concentrations anomalies were found correlate with negative (positive) BLHs relative daily means. correlation was strongest at 1400 BJT, followed by BJT 0800 BJT. Overall, nonuniformly anticorrelate BLH across anticorrelation occurred North Plain sharp contrast much weaker other regions characterized less polluted regions. averaged neutral layers higher than that convective (CBLs). CBL, where strongest, conducive dissipating more aerosol heavily area layer. CBL formed under low cloud cover, surface humidity, strong wind speed favorable dispersion aerosol, stable happen highest cover. Also, seen . findings call attention thermodynamical condition PBL should be considered when examining aerosol‐PBL interactions.

Language: Английский

---