The Bei Dou satellite system(BDS)has progressed with the full operationalization of the secondgeneration regional system(BDS-2)and the third-generation global system(BDS-3).This technology plays a crucial role in dete...The Bei Dou satellite system(BDS)has progressed with the full operationalization of the secondgeneration regional system(BDS-2)and the third-generation global system(BDS-3).This technology plays a crucial role in determining Earth Rotation Parameters(ERPs).In this study,we determine the ERPs based on the observations of BDS-2,BDS-3 and BDS-2+BDS-3,with the time spanning from August18,2022,to August 18,2023.The IERS EOP 20C04 series is used as a reference to evaluate the accuracy of the ERP estimates.We analyze the impact of different numbers of reference stations,polyhedron volumes,observation arc lengths,satellite types,and satellite systems on solving ERPs using BDS-2 and BDS-3 observation data provided by the International GNSS Service(IGS)stations.When selecting a specific satellite type,it is necessary to choose an appropriate observation arc length based on different numbers of reference stations while maximizing the volume of the formed polyhedron to achieve optimal efficiency and accuracy in parameter estimation.When both the number of reference stations and observation arc length are fixed,higher precision of the ERPs can be achieved using observations from MEO than MEO+IGSO and MEO+IGSO+GEO.Moreover,when considering only IGSO and MEO satellites as options for analysis purposes,BDS-3 provides higher accuracy compared to BDS-2.In summary,when using BDS for ERP estimation and MEO satellite observations with the same observation arc length,selecting stations from reference stations with larger polyhedral volumes can significantly improve the efficiency and accuracy of parameter estimation.展开更多
The contamination of nitric oxide presents a significant environmental challenge,necessitating the development of efficient photocatalysts for remediation.Conventional heterojunctions encounter obstacles such as large...The contamination of nitric oxide presents a significant environmental challenge,necessitating the development of efficient photocatalysts for remediation.Conventional heterojunctions encounter obstacles such as large contact barriers,sluggish charge transport,and compromised redox capacity.Here,we introduce an innovative S-type heterostructure photocatalyst,UiO-66-NH_(2)/ZnS(en)_(0.5),designed specifically to overcome these challenges.The synthesis,employing a unique microwave solvothermal method,strategically aligns the lowest unoccupied molecular orbital of UiO-66-NH_(2)with the highest occupied molecular orbital of ZnS(en)_(0.5),fostering the formation of a stepped heterojunction.The resulting intimate interface contact generates a built-in electric field,facilitating charge separation and migration,as evidenced by time-resolved photoluminescence spectroscopy and photoelectrochemical tests.The abundant active sites in the porous UiO-66-NH_(2)counterpart provide adsorption and activation sites for nitrogen monoxide(NO)oxidation.Performance evaluation reveals exceptional photocatalytic NO removal,achieving 70%efficiency and 99%selectivity toward nitrates under simulated solar illumination.Evidence from X-ray photoelectron spectroscopy and trapping experiments supports the effectiveness of the S-type heterostructure,showcasing refined reactive oxygen species,particularly superoxide.Thus,this study introduces a new perspective on advanced NO oxidation and unlocks the potential of S-scheme heterojunctions to refine reactive oxygen species for NO remediation.展开更多
基金received financial support from the National Natural Science Foundation of China(Grant No.42030105,No.42204006,No.42274011,No.42304095)Funded by State Key Laboratory of Geo-Information Engineering and Key Laboratory of Surveying and Mapping Science and Geospatial Information Technology of MNR,CASM(Grant No.2024-01-01)+2 种基金Open Fund of Hubei Luojia Laboratory(Grant No.230100020,230100019)the China Postdoctoral Science Foundation(Certificate Number:2023M743580)the Key Project of Natural Science Research in Universities of Anhui Province(No.2023AH051634)。
文摘The Bei Dou satellite system(BDS)has progressed with the full operationalization of the secondgeneration regional system(BDS-2)and the third-generation global system(BDS-3).This technology plays a crucial role in determining Earth Rotation Parameters(ERPs).In this study,we determine the ERPs based on the observations of BDS-2,BDS-3 and BDS-2+BDS-3,with the time spanning from August18,2022,to August 18,2023.The IERS EOP 20C04 series is used as a reference to evaluate the accuracy of the ERP estimates.We analyze the impact of different numbers of reference stations,polyhedron volumes,observation arc lengths,satellite types,and satellite systems on solving ERPs using BDS-2 and BDS-3 observation data provided by the International GNSS Service(IGS)stations.When selecting a specific satellite type,it is necessary to choose an appropriate observation arc length based on different numbers of reference stations while maximizing the volume of the formed polyhedron to achieve optimal efficiency and accuracy in parameter estimation.When both the number of reference stations and observation arc length are fixed,higher precision of the ERPs can be achieved using observations from MEO than MEO+IGSO and MEO+IGSO+GEO.Moreover,when considering only IGSO and MEO satellites as options for analysis purposes,BDS-3 provides higher accuracy compared to BDS-2.In summary,when using BDS for ERP estimation and MEO satellite observations with the same observation arc length,selecting stations from reference stations with larger polyhedral volumes can significantly improve the efficiency and accuracy of parameter estimation.
基金National Natural Science Foundation of China,Grant/Award Numbers:22106105,22201180Innovation Program of Shanghai Municipal Education Commission,Grant/Award Number:2019‐01‐07‐00‐E00015+3 种基金Shanghai Scientific and Technological Innovation Project,Grant/Award Number:21DZ1206300Central Guidance on Local Science and Technology Development Fund of Shanghai,Grant/Award Number:YDZX20213100003002Science and Technology Commission of Shanghai Municipality,Grant/Award Number:20060502200Program for Professor of Special Appointment,Shanghai Sailing Program,Grant/Award Number:20YF1432200。
文摘The contamination of nitric oxide presents a significant environmental challenge,necessitating the development of efficient photocatalysts for remediation.Conventional heterojunctions encounter obstacles such as large contact barriers,sluggish charge transport,and compromised redox capacity.Here,we introduce an innovative S-type heterostructure photocatalyst,UiO-66-NH_(2)/ZnS(en)_(0.5),designed specifically to overcome these challenges.The synthesis,employing a unique microwave solvothermal method,strategically aligns the lowest unoccupied molecular orbital of UiO-66-NH_(2)with the highest occupied molecular orbital of ZnS(en)_(0.5),fostering the formation of a stepped heterojunction.The resulting intimate interface contact generates a built-in electric field,facilitating charge separation and migration,as evidenced by time-resolved photoluminescence spectroscopy and photoelectrochemical tests.The abundant active sites in the porous UiO-66-NH_(2)counterpart provide adsorption and activation sites for nitrogen monoxide(NO)oxidation.Performance evaluation reveals exceptional photocatalytic NO removal,achieving 70%efficiency and 99%selectivity toward nitrates under simulated solar illumination.Evidence from X-ray photoelectron spectroscopy and trapping experiments supports the effectiveness of the S-type heterostructure,showcasing refined reactive oxygen species,particularly superoxide.Thus,this study introduces a new perspective on advanced NO oxidation and unlocks the potential of S-scheme heterojunctions to refine reactive oxygen species for NO remediation.
