Relationships between chemical elements of PM2.5 and O3 in Shanghai atmosphere based on the 1-year monitoring observation

Mass level of fine particles(PM2.5)in main cities in China has decreased significantly in recent years due to implementation of Chinese Clean Air Action Plan since 2013,however,03 pollution is getting worse than before,especially in megacities such as in Shanghai.In this work,O3 and PM2.5 were continuously monitored from May 27,2018 to March 31,2019.Our data showed that the annual average concentration of PM2.5 and O3(O3-8 hr,maximum8-hour moving average of ozone days)was 39.35±35.74 and 86.49±41.65μg/m3,respectively.The concentrations of PM2.5 showed clear seasonal trends,with higher concentrations in winter(83.36±18.66μg/m3)and lower concentrations in summer(19.85±7.23μg/m3),however,the seasonal trends of O3 were different with 103.75±41.77μg/m3 in summer and58.59±21.40μg/m3 in winter.Air mass backward trajectory,analyzing results of potential source contribution function model and concentration weighted trajectory model implied that pollutants from northwestern China contributed significantly to the mass concentration of Shanghai PM2.5,while pollutants from areas of eastern coastal provinces and South China Sea contributed significantly to the mass level of ozone in Shanghai atmosphere.Mass concentration of twenty-one elements in the PM2.5 were investigated,and their relationships with O3 were analyzed.Mass level of ozone had good correlation with that of Ba(r=0.64,p<0.05)and V(r=0.30,p>0.05),suggesting vehicle emission pollutants contribute to the increasing concentration of ozone in Shanghai atmosphere.

Studies on relationships between air pollutants and allergenicity of Humulus Scandens pollen collected from different areas of Shanghai

Pollen pollution and allergy are becoming prominent issues in China.However,few studies on pollinosis have been reported.As an allergen in the atmosphere,allergenic Humulus scandens pollen was collected from four districts of Shanghai,including Wusong(WS),Jiading(KD),Xujiahui(XJH) and Songjiang(SJ).The mass concentrations of SO2,NO2,O3,PM10,and PM2.5(particulate matter with air dynamic diameter less than 10 and 2.5 um,respectively) near the four sampling sites were also recorded during Humulus scandens pollen season.The allergenicity of the Humulus scandens pollen was assessed by using of a rat model and enzyme linked immunosorbent assay(ELISA).Relationships between the allergenicity and air pollutants were correlated.Our results demonstrated that the biological viability of the pollens collected from the four districts exhibited no significant differences.ELISA and dot blotting results further demonstrated that the serum of sensitized rats exhibited much higher immune-reactive response than that of control groups.Western blotting showed that the 15 KD(1 KD=1000 dalton) proteins of Humulus pollen led to the allergic response.The allergenic intensity of Humulus pollen protein from different samples followed the pattern:WS> JD> XJ> SJ.There was a negative relationship between the allergenicity of Humulus pollens and PM10(R=-0.99)/PM2.5(R=-0.73),and a positive relationship with O3(R=0.92).These data clearly showed that PM10 and PM2.5 could enhance Humulus pollen protein release,and 03 could aggravate the allergenicity of the Humulus pollen.

In-situ formed NiS/Ni coupled interface for efficient oxygen evolution and hydrogen evolution

High-performance electrocatalysts for water splitting are desired due to the urgent requirement of clean and sustainable hydrogen production.To reduce the energy barrier,herein,we adopt a facile in-situ surface modification strategy to develop a low-cost and efficient electrocatalyst for water splitting.The synthesized mulberry-like NiS/Ni nanoparticles exhibit excellent catalytic performance for water splitting.Small overpotentials of 301 and 161 mV are needed to drive the current density of 10 mA cm^-2 accompanying with remarkably low Tafel slopes of 46 and 74 mV dec^-1 for oxygen evolution reaction(OER)and hydrogen evolution reaction(HER),respectively.Meanwhile,a robust electrochemical stability is demonstrated.Further high-resolution X-ray photoelectron spectroscopy analyses reveal that the intrinsic HER activity improvement is attributed to the electron-enriched S on the strongly coupled NiS and Ni interface,which simultaneously facilitates the important electron transfer,consistent with the electrochemical impedance results.The post characterizations demonstrate that surface reconstructed oxyhydroxide contributes to the OER activity and NiS/Ni is an OER precatalyst.This structure construction with in-situ formation of active interface provides an effective way to design efficient electrocatalysts for energy conversion.