Cloud-to-ground(CG)lightning data and the ECMWF ERA-Interim reanalysis dataset are analyzed to gain insight into the spatiotemporal distribution and synoptic background of winter-season CG flashes between December 201...Cloud-to-ground(CG)lightning data and the ECMWF ERA-Interim reanalysis dataset are analyzed to gain insight into the spatiotemporal distribution and synoptic background of winter-season CG flashes between December 2010 and February 2020 in China.We identify three Winter Lightning Frequent Areas(WLAs):the southwest side of the Yunnan-Guizhou Plateau(WLA1),the east side of the Yunnan-Guizhou Plateau(WLA2),and the Poyang Lake Plain(WLA3).The CG lightning flashes most frequently occur at local midnight and have a monthly peak in February.The CG lightning in WLA1 is mostly generated in non-frontal weather;however,the lightning in WLA2 and WLA3 mostly occurs in frontal systems.The frontal circulation situation is divided into four typical types:transversal trough after high pressure,low vortex,confrontational convergence,and asymptotic convergence.In all typical weather patterns,the lightning occurs downstream of a 500 hPa trough and is accompanied by a southwesterly low-level jet.The convective parameters of winter thunderstorms differ greatly from those of summer thunderstorms.The maximum convective available potential energy(MCAPE)and K-index(KI)are more useful metrics than convective available potential energy(CAPE)and Showalter index(SI)during winter.This study further deepens the understanding of the distribution characteristics of winter CG lightning in China,which motivates further research to improve the ability of winter thunderstorm prediction.展开更多
Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from...Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from the South Yellow Sea.Both bacterial and archaeal communities showed a clear stratified distribution with sediment depth.The microbial communities in the upper layers were distinct from those in the deeper layers;the relative abundances of sequences of Thaumarchaeota,Gammaproteobacteria,and Actinobacteria were higher in the upper than in the deeper sediments,whereas the sequences of Bathyarchaeia,Lokiarchaeota,Euryarchaeota,Chloroflexi,and Deltaproteobacteria were relatively more abundant in the deeper sediments.Sediment depth and total organic carbon(TOC)can significantly influence both the bacterial and archaeal communities.Furthermore,bacterial and archaeal groups potentially involved in nitrogen,sulfur,and methane metabolism were detected in both sites.In our study,both ammonia-oxidizing bacteria(Nitrospira)and ammonia-oxidizing archaea(Candidatus Nitrosopumilus)were responsible for ammonia oxidization.Additionally,sulfur-reducing bacteria SEEP-SRB1 forming consortia with anaerobic methane-oxidizing archaea ANME-2 a-2 b were capable of anaerobic methane oxidation(AOM)in the 3400-02 sediment samples.展开更多
Here,we report the characteristics of bacterial communities in aerosols with different particle sizes during two persistent fog and haze events in December of 2015 and 2016 in Qingdao,China.In the early stage of pollu...Here,we report the characteristics of bacterial communities in aerosols with different particle sizes during two persistent fog and haze events in December of 2015 and 2016 in Qingdao,China.In the early stage of pollution,the accumulation of PM_(2.5) led to the accumulation of microorganisms,thus increasing the bacterial richness and diversity of fine particle sizes.With the persistence and aggravation of pollution,the toxic effect was strengthened,and the bacterial richness and diversity of each particle size decreased.When the particle concentration was highest,the richness and diversity were low for each particle size.Light haze had little influence on bacterial communities.The occurrence of highly polluted humid weather and heavy haze resulted in significant changes in bacterial community diversity,composition and structure,and air pollution exerted a greater influence than particle size on bacterial community structure.During persistent fog and haze events,with the increase of pollutants,bacteria associated with each particle size may be extensively involved in aerosol chemistry,but the degree of participation varies,which requires further study.展开更多
The interaction force between likely charged particles/surfaces is usually repulsive due to the Coulomb interaction.However,the counterintuitive like-charge attraction in electrolytes has been frequently observed in e...The interaction force between likely charged particles/surfaces is usually repulsive due to the Coulomb interaction.However,the counterintuitive like-charge attraction in electrolytes has been frequently observed in experiments,which has been theoretically debated for a long time.It is widely known that the mean field Poisson-Boltzmann theory cannot explain and predict this anomalous feature since it ignores many-body properties.In this paper,we develop efficient algorithm and perform the force calculation between two interfaces using a set of self-consistent equations which properly takes into account the electrostatic correlation and the dielectric-boundary effects.By solving the equations and calculating the pressure with the Debye-charging process,we show that the self-consistent equations could be used to study the attraction between like-charge surfaces from weak-coupling to mediate-coupling regimes,and that the attraction is due to the electrostatics-driven entropic force which is significantly enhanced by the dielectric depletion of mobile ions.A systematic investigation shows that the interaction forces can be tuned by material permittivity,ionic size and valence,and salt concentration,and that the like-charge attraction exists only for specific regime of these parameters.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42075010)the National Key R&D Program of China(Grant No.2018YFC1507304,2018YFC1507402)。
文摘Cloud-to-ground(CG)lightning data and the ECMWF ERA-Interim reanalysis dataset are analyzed to gain insight into the spatiotemporal distribution and synoptic background of winter-season CG flashes between December 2010 and February 2020 in China.We identify three Winter Lightning Frequent Areas(WLAs):the southwest side of the Yunnan-Guizhou Plateau(WLA1),the east side of the Yunnan-Guizhou Plateau(WLA2),and the Poyang Lake Plain(WLA3).The CG lightning flashes most frequently occur at local midnight and have a monthly peak in February.The CG lightning in WLA1 is mostly generated in non-frontal weather;however,the lightning in WLA2 and WLA3 mostly occurs in frontal systems.The frontal circulation situation is divided into four typical types:transversal trough after high pressure,low vortex,confrontational convergence,and asymptotic convergence.In all typical weather patterns,the lightning occurs downstream of a 500 hPa trough and is accompanied by a southwesterly low-level jet.The convective parameters of winter thunderstorms differ greatly from those of summer thunderstorms.The maximum convective available potential energy(MCAPE)and K-index(KI)are more useful metrics than convective available potential energy(CAPE)and Showalter index(SI)during winter.This study further deepens the understanding of the distribution characteristics of winter CG lightning in China,which motivates further research to improve the ability of winter thunderstorm prediction.
基金Supported by the National Key Research and Development Program of China(No.2017YFC1404402)the National Natural Science Foundation of China(Nos.41620104001,41806131)+1 种基金the Scientific and Technological Innovation Project of the Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ02)the China Postdoctoral Science Foundation(No.2018M632722)。
文摘Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from the South Yellow Sea.Both bacterial and archaeal communities showed a clear stratified distribution with sediment depth.The microbial communities in the upper layers were distinct from those in the deeper layers;the relative abundances of sequences of Thaumarchaeota,Gammaproteobacteria,and Actinobacteria were higher in the upper than in the deeper sediments,whereas the sequences of Bathyarchaeia,Lokiarchaeota,Euryarchaeota,Chloroflexi,and Deltaproteobacteria were relatively more abundant in the deeper sediments.Sediment depth and total organic carbon(TOC)can significantly influence both the bacterial and archaeal communities.Furthermore,bacterial and archaeal groups potentially involved in nitrogen,sulfur,and methane metabolism were detected in both sites.In our study,both ammonia-oxidizing bacteria(Nitrospira)and ammonia-oxidizing archaea(Candidatus Nitrosopumilus)were responsible for ammonia oxidization.Additionally,sulfur-reducing bacteria SEEP-SRB1 forming consortia with anaerobic methane-oxidizing archaea ANME-2 a-2 b were capable of anaerobic methane oxidation(AOM)in the 3400-02 sediment samples.
基金by the National Natural Science Foundation of China(Grant No.41775148)the Fundamental Research Funds for the Central Universities,China(No.201762006)the Shandong Provincial Natural Science Foundation,China(No.ZR2016CB47).
文摘Here,we report the characteristics of bacterial communities in aerosols with different particle sizes during two persistent fog and haze events in December of 2015 and 2016 in Qingdao,China.In the early stage of pollution,the accumulation of PM_(2.5) led to the accumulation of microorganisms,thus increasing the bacterial richness and diversity of fine particle sizes.With the persistence and aggravation of pollution,the toxic effect was strengthened,and the bacterial richness and diversity of each particle size decreased.When the particle concentration was highest,the richness and diversity were low for each particle size.Light haze had little influence on bacterial communities.The occurrence of highly polluted humid weather and heavy haze resulted in significant changes in bacterial community diversity,composition and structure,and air pollution exerted a greater influence than particle size on bacterial community structure.During persistent fog and haze events,with the increase of pollutants,bacteria associated with each particle size may be extensively involved in aerosol chemistry,but the degree of participation varies,which requires further study.
基金The authors acknowledge the financial support from the Natural Science Foundation of China(Grant Numbers:11101276,and 91130012),Youth Talents Program by Chinese Organization Department,and the HPC center of Shanghai Jiao Tong University.
文摘The interaction force between likely charged particles/surfaces is usually repulsive due to the Coulomb interaction.However,the counterintuitive like-charge attraction in electrolytes has been frequently observed in experiments,which has been theoretically debated for a long time.It is widely known that the mean field Poisson-Boltzmann theory cannot explain and predict this anomalous feature since it ignores many-body properties.In this paper,we develop efficient algorithm and perform the force calculation between two interfaces using a set of self-consistent equations which properly takes into account the electrostatic correlation and the dielectric-boundary effects.By solving the equations and calculating the pressure with the Debye-charging process,we show that the self-consistent equations could be used to study the attraction between like-charge surfaces from weak-coupling to mediate-coupling regimes,and that the attraction is due to the electrostatics-driven entropic force which is significantly enhanced by the dielectric depletion of mobile ions.A systematic investigation shows that the interaction forces can be tuned by material permittivity,ionic size and valence,and salt concentration,and that the like-charge attraction exists only for specific regime of these parameters.
