Identification of ocean eddies from a large amount of ocean data provided by satellite measurements and numerical simulations is crucial,while the academia has invented many traditional physical methods with accurate ...Identification of ocean eddies from a large amount of ocean data provided by satellite measurements and numerical simulations is crucial,while the academia has invented many traditional physical methods with accurate detection capability,but their detection computational efficiency is low.In recent years,with the increasing application of deep learning in ocean feature detection,many deep learning-based eddy detection models have been developed for more effective eddy detection from ocean data.But it is difficult for them to precisely fit some physical features implicit in traditional methods,leading to inaccurate identification of ocean eddies.In this study,to address the low efficiency of traditional physical methods and the low detection accuracy of deep learning models,we propose a solution that combines the target detection model Faster Region with CNN feature(Faster R-CNN)with the traditional dynamic algorithm Angular Momentum Eddy Detection and Tracking Algorithm(AMEDA).We use Faster R-CNN to detect and generate bounding boxes for eddies,allowing AMEDA to detect the eddy center within these bounding boxes,thus reducing the complexity of center detection.To demonstrate the detection efficiency and accuracy of this model,this paper compares the experimental results with AMEDA and the deep learningbased eddy detection method eddyNet.The results show that the eddy detection results of this paper are more accurate than eddyNet and have higher execution efficiency than AMEDA.展开更多
Rational regulation of stable graphitic carbon nitride(CN)for superior peroxymonosulfate(PMS)activation is important in the catalytic degradation of water contaminants.In this work,the copper oxide and oxygen co-doped...Rational regulation of stable graphitic carbon nitride(CN)for superior peroxymonosulfate(PMS)activation is important in the catalytic degradation of water contaminants.In this work,the copper oxide and oxygen co-doped graphitic carbon nitride(Cu O/O-CN)was prepared via one-step synthesis and applied in activating PMS for oxytetracycline(OTC)degradation,displaying superior catalytic performance.Systematic characterization and theoretical calculations indicated that the synergistic effect between the oxygen site of CN and CuO can modulate the electronic structure of the whole composite further facilitating the formation of non-radical^(1)O_(2)and various reactive radicals.Results of the influencing factor experiments revealed that CuO/O-CN has a strong resistance to the environmental impact.The degradation efficiency of OTC in the real water environment even exceeded that in the deionized water.After four successive runs of the optimal catalyst,the OTC removal rate was still as high as 91.3%.This work developed a high-efficiency PMS activator to remove refractory pollutants via both radical pathway and non-radical pathway,which showed a promising potential in the treatment of wastewaters.展开更多
The formation, composition and evolution of the oldest continental crust is the logical starting point for discussing the differentiation and development of the crust-mantle system and the tectonic evolution of the Ea...The formation, composition and evolution of the oldest continental crust is the logical starting point for discussing the differentiation and development of the crust-mantle system and the tectonic evolution of the Earth. Searching for and identifying the oldest continental crust and investigating the processes and periodicity of crust formation and its subsequent development into cratons is a primary scientific topic of worldwide research [1]. The other important issues related to early Precambrian evolution include identifying tectonic divisions and determining the onset of plate tectonics. However, the rarity of preserved ancient continental crust due to its long-term reworking makes this research extremely challenging. Thus, finding and identifying the oldest rocks and zircons is the beginning of very exciting and important research. The occurrence of >3.8 Ga rocks in northern and eastern Canada, West Greenland and eastern Antarctica are difficult to access and so it is important to identify other occurrences of such rocks.展开更多
The amount of zircon U-Pb geochronological data for China has grown rapidly in recent years.Nearly 410,000 items of zircon U-Pb geochronological data,representing more than 7,000 relevant articles in the Elsevier Scie...The amount of zircon U-Pb geochronological data for China has grown rapidly in recent years.Nearly 410,000 items of zircon U-Pb geochronological data,representing more than 7,000 relevant articles in the Elsevier Science Database,have been collected to a database in this research.Statistics on the ages and absolute errors of these collated data,yielded smallest standard errors for(206Pb/238U),(207Pb/235U),and(207Pb/206Pb)ages within respective time intervals of<1388.96 Ma,1388.96–3282.52 Ma,and>3282.52 Ma.The ages and their absolute errors were determined using three main geochronology methods,based on laser ablation inductively coupled mass spectrometer(LA-ICP-MS),sensitive high-resolution ion microprobe(SHRIMP),and secondary ion mass spectrometer(SIMS)measurements.We compared the influence of these different methods on errors for each age interval.In addition,using a Gaussian model of multi-peak fitting of zircon U-Pb age frequencies,we identified seven growth peaks in zircons from the Chinese continental crust,which are 48.60 Ma,131.49 Ma,249.91 Ma,444.27 Ma,835.95 Ma,1860.65 Ma,and 2505.54 Ma.It is clear that there are correspondences between these ages and various geological events,namely,the Wutai movement,Lvliang movement,Jinning movement,Caledonian movement,Indo-China movement,Yanshan movement,and Himalayaorogeny movement,respectively.The time and spatial distributions of these zircons correspond to distinct geological events on the Chinese continent,reflecting its crustal evolution.展开更多
The zircon U-Pb chronology database provides a good opportunity to obtain important zircon growth peak periods in the Earth’s history so as to study the origin and evolution of the crust.It should be noted that resea...The zircon U-Pb chronology database provides a good opportunity to obtain important zircon growth peak periods in the Earth’s history so as to study the origin and evolution of the crust.It should be noted that research preference affects the objectivity of zircon sampling,leading to hot data in the database and age statistics.To evaluate the influence of hot data on statistical results,the W and Y indexes are introduced.Using a Gaussian model of multipeak fitting of zircon U-Pb age frequencies,we identify seven major growth peaks in zircons from the Chinese continental crust,which are 2498.95,1855.82,828.88,444.29,249.46,131.96,and 58.21 Ma.Due to differences in the time scales of zircon growth peaks,these peaks can be divided into two categories:first-order zircon growth peaks(Ⅰ)and second-order zircon growth peaks(Ⅱ),which represent longer and shorter time scales,perhaps due to different kinds of geological dynamics,respectively.In addition,there are clear correspondences between these ages and various geological events recognized by most scholars,namely,the Wutai orogeny,Lvliang orogeny,Jinning orogeny,Caledonian orogeny,Indosinian orogeny,Yanshanian orogeny,and Himalayan orogeny,respectively.展开更多
Single_zircon evaporation method was employed in the present study to determine the age of the iron_bearing rock series in Precambrian strata in the western sector of the northern Qilian Mountains. Three zircon ages f...Single_zircon evaporation method was employed in the present study to determine the age of the iron_bearing rock series in Precambrian strata in the western sector of the northern Qilian Mountains. Three zircon ages from the diabase of the Aoyougou ophiolite previously put into Upper Lithologic Formation of the Zhulongguan Group are (1 840±2), (1 783±2) and (1 784±2) Ma respectively, whereas the zircon ages from the welded breccias in the Zhulongguan Group are (733±7), (738±4) and (604±6) Ma respectively. These results show that they should belong to the bottom of the middle Proterozoic and the upper part of upper Proterozoic respectively.展开更多
基金the National Science Foundation of China(No.42175194)the National Natural Science Foundation of China(No.41976165)for funding this work.
文摘Identification of ocean eddies from a large amount of ocean data provided by satellite measurements and numerical simulations is crucial,while the academia has invented many traditional physical methods with accurate detection capability,but their detection computational efficiency is low.In recent years,with the increasing application of deep learning in ocean feature detection,many deep learning-based eddy detection models have been developed for more effective eddy detection from ocean data.But it is difficult for them to precisely fit some physical features implicit in traditional methods,leading to inaccurate identification of ocean eddies.In this study,to address the low efficiency of traditional physical methods and the low detection accuracy of deep learning models,we propose a solution that combines the target detection model Faster Region with CNN feature(Faster R-CNN)with the traditional dynamic algorithm Angular Momentum Eddy Detection and Tracking Algorithm(AMEDA).We use Faster R-CNN to detect and generate bounding boxes for eddies,allowing AMEDA to detect the eddy center within these bounding boxes,thus reducing the complexity of center detection.To demonstrate the detection efficiency and accuracy of this model,this paper compares the experimental results with AMEDA and the deep learningbased eddy detection method eddyNet.The results show that the eddy detection results of this paper are more accurate than eddyNet and have higher execution efficiency than AMEDA.
基金financially supported by the program for the National Natural Science Foundation of China(Nos.52170162,51809090,52100182,52100180)the Natural Science Foundation of Hunan Province,China(Nos.2022JJ10016,2019JJ50077,2021JJ40087)+4 种基金the Science and Technology Innovation Program of Hunan Province(No.2021RC3049)the Fundamental Research Funds for the Central Universities(No.531118010114)the China National Postdoctoral Program for Innovative Talents(No.BX20200119)the Project Funded by China Postdoctoral Science Foundation(No.2021M690961)the Fundamental Research Funds for the Central Universities(No.531118010114)。
文摘Rational regulation of stable graphitic carbon nitride(CN)for superior peroxymonosulfate(PMS)activation is important in the catalytic degradation of water contaminants.In this work,the copper oxide and oxygen co-doped graphitic carbon nitride(Cu O/O-CN)was prepared via one-step synthesis and applied in activating PMS for oxytetracycline(OTC)degradation,displaying superior catalytic performance.Systematic characterization and theoretical calculations indicated that the synergistic effect between the oxygen site of CN and CuO can modulate the electronic structure of the whole composite further facilitating the formation of non-radical^(1)O_(2)and various reactive radicals.Results of the influencing factor experiments revealed that CuO/O-CN has a strong resistance to the environmental impact.The degradation efficiency of OTC in the real water environment even exceeded that in the deionized water.After four successive runs of the optimal catalyst,the OTC removal rate was still as high as 91.3%.This work developed a high-efficiency PMS activator to remove refractory pollutants via both radical pathway and non-radical pathway,which showed a promising potential in the treatment of wastewaters.
基金supported by the National Natural Science Foundation of China(41472169)the Key Program of the Ministry of Nature and Resources of China(121201102000150012)
文摘The formation, composition and evolution of the oldest continental crust is the logical starting point for discussing the differentiation and development of the crust-mantle system and the tectonic evolution of the Earth. Searching for and identifying the oldest continental crust and investigating the processes and periodicity of crust formation and its subsequent development into cratons is a primary scientific topic of worldwide research [1]. The other important issues related to early Precambrian evolution include identifying tectonic divisions and determining the onset of plate tectonics. However, the rarity of preserved ancient continental crust due to its long-term reworking makes this research extremely challenging. Thus, finding and identifying the oldest rocks and zircons is the beginning of very exciting and important research. The occurrence of >3.8 Ga rocks in northern and eastern Canada, West Greenland and eastern Antarctica are difficult to access and so it is important to identify other occurrences of such rocks.
基金This work was supported by the National Key R&D Program,focused special funding[2017YFC0601203]the National Innovation Training Program for Undergraduate Students[Grant 201810001028].
文摘The amount of zircon U-Pb geochronological data for China has grown rapidly in recent years.Nearly 410,000 items of zircon U-Pb geochronological data,representing more than 7,000 relevant articles in the Elsevier Science Database,have been collected to a database in this research.Statistics on the ages and absolute errors of these collated data,yielded smallest standard errors for(206Pb/238U),(207Pb/235U),and(207Pb/206Pb)ages within respective time intervals of<1388.96 Ma,1388.96–3282.52 Ma,and>3282.52 Ma.The ages and their absolute errors were determined using three main geochronology methods,based on laser ablation inductively coupled mass spectrometer(LA-ICP-MS),sensitive high-resolution ion microprobe(SHRIMP),and secondary ion mass spectrometer(SIMS)measurements.We compared the influence of these different methods on errors for each age interval.In addition,using a Gaussian model of multi-peak fitting of zircon U-Pb age frequencies,we identified seven growth peaks in zircons from the Chinese continental crust,which are 48.60 Ma,131.49 Ma,249.91 Ma,444.27 Ma,835.95 Ma,1860.65 Ma,and 2505.54 Ma.It is clear that there are correspondences between these ages and various geological events,namely,the Wutai movement,Lvliang movement,Jinning movement,Caledonian movement,Indo-China movement,Yanshan movement,and Himalayaorogeny movement,respectively.The time and spatial distributions of these zircons correspond to distinct geological events on the Chinese continent,reflecting its crustal evolution.
基金supported by the National Key R&D Program of China,focused special funding[grant number 2017YFC0601203].
文摘The zircon U-Pb chronology database provides a good opportunity to obtain important zircon growth peak periods in the Earth’s history so as to study the origin and evolution of the crust.It should be noted that research preference affects the objectivity of zircon sampling,leading to hot data in the database and age statistics.To evaluate the influence of hot data on statistical results,the W and Y indexes are introduced.Using a Gaussian model of multipeak fitting of zircon U-Pb age frequencies,we identify seven major growth peaks in zircons from the Chinese continental crust,which are 2498.95,1855.82,828.88,444.29,249.46,131.96,and 58.21 Ma.Due to differences in the time scales of zircon growth peaks,these peaks can be divided into two categories:first-order zircon growth peaks(Ⅰ)and second-order zircon growth peaks(Ⅱ),which represent longer and shorter time scales,perhaps due to different kinds of geological dynamics,respectively.In addition,there are clear correspondences between these ages and various geological events recognized by most scholars,namely,the Wutai orogeny,Lvliang orogeny,Jinning orogeny,Caledonian orogeny,Indosinian orogeny,Yanshanian orogeny,and Himalayan orogeny,respectively.
文摘Single_zircon evaporation method was employed in the present study to determine the age of the iron_bearing rock series in Precambrian strata in the western sector of the northern Qilian Mountains. Three zircon ages from the diabase of the Aoyougou ophiolite previously put into Upper Lithologic Formation of the Zhulongguan Group are (1 840±2), (1 783±2) and (1 784±2) Ma respectively, whereas the zircon ages from the welded breccias in the Zhulongguan Group are (733±7), (738±4) and (604±6) Ma respectively. These results show that they should belong to the bottom of the middle Proterozoic and the upper part of upper Proterozoic respectively.
