English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Particulate matter (PM) pollution on the peripheries of Chinese megacitiescan be as serious as in cities themselves. Given the substantial vehicularemissions in inner-city areas, the direct transport of primary PM (e.g.,black carbon and primary organics) and effective formation of secondary PMfrom precursors (e.g., NOx and volatile organic compounds)can contribute to PM pollution in <q>buffer</q> zones between cities. Toinvestigate how traffic emissions in inner-city areas impact these adjacentbuffer zones, a suite of real-time instruments were deployed in Panyu,downwind from central Guangzhou, from November to December 2014. Nitrate massfraction was higher on high-PM days, with the average nitrate-to-sulfateratio increasing from around 0.35 to 1.5 as the PM mass concentrationincreased from 10 to 160 µg m−3. Particulate nitrate wasstrongly correlated with excess ammonium(([NH4+] ∕ [SO42−] − 1.5)  ×  [SO42−]), with higher concentrations in December than inNovember due to lower temperatures. The organic mass fraction was the highestacross all PM1 levels throughout the campaign. While organic aerosols(OA) were dominated by secondary organic aerosols (SOA  =  semi-volatileoxygenated organic aerosols + low-volatility oxygenated organic aerosols)as a campaign average, freshly emitted hydrocarbon-like organic aerosols(HOA) contributed up to 40 % of OA during high-OA periods, whichtypically occurred at nighttime and contributed 23.8 to 28.4 % onaverage. This was due to daytime traffic restrictions on heavy-duty vehiclesin Guangzhou, and HOA almost increased linearly with total OA concentration.SOA increased as odd oxygen(Ox  =  O3 + NO2) increased duringthe day due to photochemistry. A combination of nighttime traffic emissionsand daytime photochemistry contributed to the buildup of PM in Panyu. Themitigation of PM pollution in inner-city areas by reducing vehicular trafficcan potentially improve air quality in peripheral areas

Impacts of traffic emissions on atmospheric particulate nitrate and organics at a downwind site on the periphery of Guangzhou, China