Cloud vertical structure(CVS)strongly affects atmospheric circulation and radiative transfer.Yet,long-term,groundbased observations are scarce over the Tibetan Plateau(TP)despite its vital role in global climate.This ...Cloud vertical structure(CVS)strongly affects atmospheric circulation and radiative transfer.Yet,long-term,groundbased observations are scarce over the Tibetan Plateau(TP)despite its vital role in global climate.This study utilizes ground-based lidar and Ka-band cloud profiling radar(KaCR)measurements at Yangbajain(YBJ),TP,from October 2021 to September 2022 to characterize cloud properties.A satisfactorily performing novel anomaly detection algorithm(LevelShiftAD)is proposed for lidar and KaCR profiles to identify cloud boundaries.Cloud base heights(CBH)retrieved from KaCR and lidar observations show good consistency,with a correlation coefficient of 0.78 and a mean difference of-0.06 km.Cloud top heights(CTH)derived from KaCR match the FengYun-4A and Himawari-8 products well.Thus,KaCR measurements serve as the primary dataset for investigating CVSs over the TP.Different diurnal cycles occur in summer and winter.The diurnal cycle is characterized by a pronounced increase in cloud occurrence frequency in the afternoon with an early-morning decrease in winter,while cloud amounts remain high all day,with scattered nocturnal increases in summer.Summer features more frequent clouds with larger geometrical thicknesses,a higher multi-layer ratio,and greater inter-cloud spacing.Around 26%of the cloud bases occur below 0.5 km.Winter exhibits a bimodal distribution of cloud base heights with peaks at 0-0.5 km and 2-2.5 km.Single-layer and geometrically thin clouds prevail at YBJ.This study enriches long-term measurements of CVSs over the TP,and the robust anomaly detection method helps quantify cloud macro-physical properties via synergistic lidar and radar observations.展开更多
Aflatoxin B1(AFB1),a potent carcinogen widely prevalent in food commodities,necessitates reliable detection methods.In this study,we developed a novel dual-signal electrochemical aptasensor for AFB1 detection,employin...Aflatoxin B1(AFB1),a potent carcinogen widely prevalent in food commodities,necessitates reliable detection methods.In this study,we developed a novel dual-signal electrochemical aptasensor for AFB1 detection,employing PtCuNi/Apt/Thi and[Fe(CN)6]^(3/4-)as probes in conjunction with a synergistic signal amplification strategy.The hexagonal star-shaped PtCuNi nanomaterial,synthesized via a one-pot hydrothermal method,exhibits an enlarged specific surface area and abundant active sites,thereby enhancing both aptamer conjugation capacity and probe loading efficiency.The AFB1-triggered hybridization chain reaction(HCR)was employed as a signal amplification strategy.Under the combined effect of the three elements,the ternary alloy PtCuNi has better catalytic activity and higher stability compared to binary alloy PtCu and PtNi.The developed aptasensor demonstrated excellent detection performance,featuring a wide linear range from 5 pg/mL to 200 ng/mL with a low detection limit of 0.688 pg/mL.The aptasensor exhibited remarkable specificity,repeatability,and stability.Furthermore,the sensor exhibited excellent detection performance when analyzing real samples such as cornmeal and edible oil.For quality control samples including feed and edible oil,it demonstrated comparable capability to the HPLC method.The dual-signal system improved the detection accuracy and sensitivity by simultaneously measuring two distinct electrochemical signals,enabling mutual calibration and verification.展开更多
基金jointly funded by the Second Tibetan Plateau Scientific Expedition and Research Program of China under Grant 2019QZKK0604the National Natural Science Foundation of China(Grant Nos.92044303 and 42001294).
文摘Cloud vertical structure(CVS)strongly affects atmospheric circulation and radiative transfer.Yet,long-term,groundbased observations are scarce over the Tibetan Plateau(TP)despite its vital role in global climate.This study utilizes ground-based lidar and Ka-band cloud profiling radar(KaCR)measurements at Yangbajain(YBJ),TP,from October 2021 to September 2022 to characterize cloud properties.A satisfactorily performing novel anomaly detection algorithm(LevelShiftAD)is proposed for lidar and KaCR profiles to identify cloud boundaries.Cloud base heights(CBH)retrieved from KaCR and lidar observations show good consistency,with a correlation coefficient of 0.78 and a mean difference of-0.06 km.Cloud top heights(CTH)derived from KaCR match the FengYun-4A and Himawari-8 products well.Thus,KaCR measurements serve as the primary dataset for investigating CVSs over the TP.Different diurnal cycles occur in summer and winter.The diurnal cycle is characterized by a pronounced increase in cloud occurrence frequency in the afternoon with an early-morning decrease in winter,while cloud amounts remain high all day,with scattered nocturnal increases in summer.Summer features more frequent clouds with larger geometrical thicknesses,a higher multi-layer ratio,and greater inter-cloud spacing.Around 26%of the cloud bases occur below 0.5 km.Winter exhibits a bimodal distribution of cloud base heights with peaks at 0-0.5 km and 2-2.5 km.Single-layer and geometrically thin clouds prevail at YBJ.This study enriches long-term measurements of CVSs over the TP,and the robust anomaly detection method helps quantify cloud macro-physical properties via synergistic lidar and radar observations.
基金funded by the Key Scientific and Technological Project of Henan Province(242102320270)Special Project for Collaborative Innovation of Zhengzhou(21ZZXTCX15).
文摘Aflatoxin B1(AFB1),a potent carcinogen widely prevalent in food commodities,necessitates reliable detection methods.In this study,we developed a novel dual-signal electrochemical aptasensor for AFB1 detection,employing PtCuNi/Apt/Thi and[Fe(CN)6]^(3/4-)as probes in conjunction with a synergistic signal amplification strategy.The hexagonal star-shaped PtCuNi nanomaterial,synthesized via a one-pot hydrothermal method,exhibits an enlarged specific surface area and abundant active sites,thereby enhancing both aptamer conjugation capacity and probe loading efficiency.The AFB1-triggered hybridization chain reaction(HCR)was employed as a signal amplification strategy.Under the combined effect of the three elements,the ternary alloy PtCuNi has better catalytic activity and higher stability compared to binary alloy PtCu and PtNi.The developed aptasensor demonstrated excellent detection performance,featuring a wide linear range from 5 pg/mL to 200 ng/mL with a low detection limit of 0.688 pg/mL.The aptasensor exhibited remarkable specificity,repeatability,and stability.Furthermore,the sensor exhibited excellent detection performance when analyzing real samples such as cornmeal and edible oil.For quality control samples including feed and edible oil,it demonstrated comparable capability to the HPLC method.The dual-signal system improved the detection accuracy and sensitivity by simultaneously measuring two distinct electrochemical signals,enabling mutual calibration and verification.
