The authors report the results of aethalometer black carbon(BC)aerosol measurements carried out over a rural(pristine)site,Panchgaon,Haryana State,India during the winter months of 2021-2022 and 2022-2023.They are com...The authors report the results of aethalometer black carbon(BC)aerosol measurements carried out over a rural(pristine)site,Panchgaon,Haryana State,India during the winter months of 2021-2022 and 2022-2023.They are compared with collocated and concurrent observations from the Air Quality Monitoring Station(AQMS),which provides synchronous air pollution and surface meteorological parameters.Secular variations in BC mass concentration are studied and explained with variations in local meteorological parameters.The biomass burning fire count retrievals from NASA-NOAA VIIRS satellite,and backward airmass trajectories from NOAA-ERL HYSPLIT Model analysis have also been utilized to explain the findings.They reveal that the north-west Indian region contributes maximum to the BC mass concentration over the study site during the study period.Moreover,the observed BC mass concentrations corroborate the synchronous fire count,primary and secondary pollutant concentrations.The results were found to aid the development of mitigation methods to achieve a sustainable climate system.展开更多
对DP590双相钢点焊接头进行正交试验,研究不同工艺因素对点焊接头失效载荷和焊核直径的影响,确定最优点焊工艺参数,并探讨点焊接头压痕深度的超声测量方法.采用超声波水浸聚焦入射法对1.5 mm厚的DP590双相钢点焊接头进行超声C扫描,获得...对DP590双相钢点焊接头进行正交试验,研究不同工艺因素对点焊接头失效载荷和焊核直径的影响,确定最优点焊工艺参数,并探讨点焊接头压痕深度的超声测量方法.采用超声波水浸聚焦入射法对1.5 mm厚的DP590双相钢点焊接头进行超声C扫描,获得接头焊核直径,利用超声A扫信号,计算点焊接头压痕深度,并与实际测量结果对比.研究表明:焊接参数对DP590点焊接头的失效载荷与焊核直径的显著性影响一致,从大到小依次为焊接电流、焊接时间、电极压力;DP590点焊接头最优的焊接工艺参数为:焊接时间70 ms,焊接电流15.0 k A,电极压力6.5 k N,在此参数下接头的抗拉强度为9 521.4 N;超声A扫信号计算得到的点焊接头表面压痕率与实际压痕率的误差在2.5%~9.7%,超声计算所得压痕深度与实际测量压痕率较为接近.展开更多
文摘The authors report the results of aethalometer black carbon(BC)aerosol measurements carried out over a rural(pristine)site,Panchgaon,Haryana State,India during the winter months of 2021-2022 and 2022-2023.They are compared with collocated and concurrent observations from the Air Quality Monitoring Station(AQMS),which provides synchronous air pollution and surface meteorological parameters.Secular variations in BC mass concentration are studied and explained with variations in local meteorological parameters.The biomass burning fire count retrievals from NASA-NOAA VIIRS satellite,and backward airmass trajectories from NOAA-ERL HYSPLIT Model analysis have also been utilized to explain the findings.They reveal that the north-west Indian region contributes maximum to the BC mass concentration over the study site during the study period.Moreover,the observed BC mass concentrations corroborate the synchronous fire count,primary and secondary pollutant concentrations.The results were found to aid the development of mitigation methods to achieve a sustainable climate system.
文摘对DP590双相钢点焊接头进行正交试验,研究不同工艺因素对点焊接头失效载荷和焊核直径的影响,确定最优点焊工艺参数,并探讨点焊接头压痕深度的超声测量方法.采用超声波水浸聚焦入射法对1.5 mm厚的DP590双相钢点焊接头进行超声C扫描,获得接头焊核直径,利用超声A扫信号,计算点焊接头压痕深度,并与实际测量结果对比.研究表明:焊接参数对DP590点焊接头的失效载荷与焊核直径的显著性影响一致,从大到小依次为焊接电流、焊接时间、电极压力;DP590点焊接头最优的焊接工艺参数为:焊接时间70 ms,焊接电流15.0 k A,电极压力6.5 k N,在此参数下接头的抗拉强度为9 521.4 N;超声A扫信号计算得到的点焊接头表面压痕率与实际压痕率的误差在2.5%~9.7%,超声计算所得压痕深度与实际测量压痕率较为接近.