In energy-dispersive X-ray fluorescence spectroscopy,the estimation of the pulse amplitude determines the accuracy of the spectrum measurement.The error generated by the amplitude estimation of the pulse output distor...In energy-dispersive X-ray fluorescence spectroscopy,the estimation of the pulse amplitude determines the accuracy of the spectrum measurement.The error generated by the amplitude estimation of the pulse output distorted by the measurement system leads to false peaks in the measured spectrum.To eliminate these false peaks and achieve an accurate estimation of the distorted pulse amplitude,a composite neural network model is proposed,which embeds long and short-term memory(LSTM)into the UNet structure.The UNet network realizes the fusion of pulse sequence features and the LSTM model realizes pulse amplitude estimation.The model is trained using simulated pulse datasets with different amplitudes and distortion times.For the pulse height estimation,the average relative error of the trained model on the test set was approximately 0.64%,which is 27.37% lower than that of the traditional trapezoidal shaping algorithm.Offline processing of a standard iron source further validated the pulse height estimation performance of the UNet-LSTM model.After estimating the amplitude of the distorted pulses using the model,the false peak area was reduced by approximately 91% over the full spectrum and was corrected to the characteristic peak region of interest(ROI).The corrected peak area accounted for approximately 1.32%of the characteristic peak ROI area.The results indicate that the model can accurately estimate the height of distorted pulses and has substantial corrective effects on false peaks.展开更多
Cadmium(Cd)and lead(Pb)contaminated soils that are used for food production can lead to metal bioaccumulation in the food chain and eventually affect human health.In these agroecosystems,means by which Cd and Pb bioav...Cadmium(Cd)and lead(Pb)contaminated soils that are used for food production can lead to metal bioaccumulation in the food chain and eventually affect human health.In these agroecosystems,means by which Cd and Pb bioavailability can be reduced are desperately required,with biochar as a proxy for bioavailability reductions.Molecular Cd and Pb sorption mecha-nisms within short-(0-2 years)or long-term(8-10 years)time periods following biochar application to a contaminated rice paddy soil were investigated.A combination of Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,and soft X-ray imaging was utilized to discern potential metal sorption mechanisms.Following both short-and long-term biochar applications,soil Cd and Pb bioavailable fractions shifted partially towards metal(hydr)oxide and carbonate pre-cipitates,and partially towards biochar-organic function group associations;oxygen-containing groups,such as C=O and O-H,appeared to bind Cd and Pb.Soft X-ray imaging results suggested that heavy metals were primarily sorbed on biochar exterior surfaces,yet given time and particle disintegration,metals sorbed onto biochar interior pore walls.Findings sug-gest that biochar may play a pivotal role in reducing long-term bioavailable Cd and Pb in contaminated soils.Observations also support previous findings that suggest biochar use can lead to reduced heavy metal transfer to plants and potentially to reduced heavy metal consumption by humans.展开更多
基金supported by the Open Project of Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology(No.NLK2022-05)the Central Government Guidance Funds for Local Scientific and Technological Development,China(No.Guike ZY22096024)+5 种基金the Sichuan Natural Science Youth Fund Project(No.2023NSFSC1366)Key R&D Projects of Sichuan Provincial Department of Science and Technology(No.2023YFG0287)the Open Research Fund of National Engineering Research Center for Agro-Ecological Big Data Analysis&Application,Anhui University(No.AE202209)the National Natural Science Youth Foundation of China(No.12305214)the Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province(No.2023FTSZ03)the Key Laboratory of Interior Layout optimization and Security,Institutions of Higher Education of Sichuan Province(No.2023SNKJ-01)。
文摘In energy-dispersive X-ray fluorescence spectroscopy,the estimation of the pulse amplitude determines the accuracy of the spectrum measurement.The error generated by the amplitude estimation of the pulse output distorted by the measurement system leads to false peaks in the measured spectrum.To eliminate these false peaks and achieve an accurate estimation of the distorted pulse amplitude,a composite neural network model is proposed,which embeds long and short-term memory(LSTM)into the UNet structure.The UNet network realizes the fusion of pulse sequence features and the LSTM model realizes pulse amplitude estimation.The model is trained using simulated pulse datasets with different amplitudes and distortion times.For the pulse height estimation,the average relative error of the trained model on the test set was approximately 0.64%,which is 27.37% lower than that of the traditional trapezoidal shaping algorithm.Offline processing of a standard iron source further validated the pulse height estimation performance of the UNet-LSTM model.After estimating the amplitude of the distorted pulses using the model,the false peak area was reduced by approximately 91% over the full spectrum and was corrected to the characteristic peak region of interest(ROI).The corrected peak area accounted for approximately 1.32%of the characteristic peak ROI area.The results indicate that the model can accurately estimate the height of distorted pulses and has substantial corrective effects on false peaks.
基金This study was partially supported by,the National Natural Science Foundation of China under a grant number of 41501339,21677119Jiangsu Province Science Foundation for Youths under a grant number of BK20140468sponsored by the QingLan Project.
文摘Cadmium(Cd)and lead(Pb)contaminated soils that are used for food production can lead to metal bioaccumulation in the food chain and eventually affect human health.In these agroecosystems,means by which Cd and Pb bioavailability can be reduced are desperately required,with biochar as a proxy for bioavailability reductions.Molecular Cd and Pb sorption mecha-nisms within short-(0-2 years)or long-term(8-10 years)time periods following biochar application to a contaminated rice paddy soil were investigated.A combination of Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,and soft X-ray imaging was utilized to discern potential metal sorption mechanisms.Following both short-and long-term biochar applications,soil Cd and Pb bioavailable fractions shifted partially towards metal(hydr)oxide and carbonate pre-cipitates,and partially towards biochar-organic function group associations;oxygen-containing groups,such as C=O and O-H,appeared to bind Cd and Pb.Soft X-ray imaging results suggested that heavy metals were primarily sorbed on biochar exterior surfaces,yet given time and particle disintegration,metals sorbed onto biochar interior pore walls.Findings sug-gest that biochar may play a pivotal role in reducing long-term bioavailable Cd and Pb in contaminated soils.Observations also support previous findings that suggest biochar use can lead to reduced heavy metal transfer to plants and potentially to reduced heavy metal consumption by humans.
