| 2 | Quantifying the impacts of emissions and meteorology on the interannual variations of air pollutants in major Chinese cities from 2015 to 2021显示文摘Air pollutant concentration is a function of emission rates and meteorology.To accurately evaluate the effect of control measures,the meteorological covariate must be corrected from the observations.This study quantified the impacts of emission abatement and meteorological condition on the interannual variations of SO_(2),NO_(2),CO,O_(3),PM_(10) and PM_(2.5) concentrations in 31 major Chinese cities using an optimized machine learning-based meteorological normalization technique.Overall,the annual average concentrations of SO_(2),NO_(2),CO,PM_(10)and PM_(2.5)were reduced by 86%,51%,99%,86% and 88%from 2015 to 2020,respectively,in the studied cities,attributable to their emission reductions.However,the concentration of O_(3) was found with no significant decrease with the reduction of precursors.Emission abatement notably improved air quality between 2015 and 2018.Such a decline in emissions tended to progressively slow down since 2018.Overall,the meteorological conditions in 2016–2017 and 2018–2019 were unfavorable for a better air quality,while it became favorable in 2020–2021.Specifically,emission abatement in 2021 further lowered the concentrations of SO_(2),NO_(2),CO,and PM_(2.5),while the emission of PM_(10) increased.And changes in precursors emissions worsened O_(3) air quality.To meet the demand of improving air quality,more aggressive abatement measures need to be formulated to synergistically reduce NOx,volatile organic compounds,and coarse particles. | Qili DAI Tianjiao DAI Linlu HOU Linxuan LI Xiaohui BI Yufen ZHANG Yinchang FENG | 2023 | Science China Earth Sciences2023，66，8： | 0 |
| 3 | Improving the band alignment at PtSe_(2)grain boundaries with selective adsorption of TCNQ显示文摘Grain boundaries in two-dimensional(2D)semiconductors generally induce distorted band alignment and interfacial charge,which impair their electronic properties for device applications.Here,we report the improvement of band alignment at the grain boundaries of PtSe_(2),a 2D semiconductor,with selective adsorption of a presentative organic acceptor,tetracyanoquinodimethane(TCNQ).TCNQ molecules show selective adsorption at the PtSe_(2)grain boundary with strong interfacial charge.The adsorption of TCNQ distinctly improves the band alignment at the PtSe_(2)grain boundaries.With the charge transfer between the grain boundary and TCNQ,the local charge is inhibited,and the band bending at the grain boundary is suppressed,as revealed by the scanning tunneling microscopy and spectroscopy(STM/S)results.Our finding provides an effective method for the advancement of the band alignment at the grain boundary by functional molecules,improving the electronic properties of 2D semiconductors for their future applications. | Yanhui Hou Ziqiang Xu Yan Shao Linlu Wu Zhongliu Liu Genyu Hu Wei Ji Jingsi Qiao Xu Wu Hong-Jun Gao Yeliang Wang | 2023 | Nano Research2023，16，2： | 0 |
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