Batteries,fuel cells,and supercapacitors are electrochemical devices already on the market and still need a boost in kinetics to match the high energy density demand of applications.Perovskites have attracted the scie...Batteries,fuel cells,and supercapacitors are electrochemical devices already on the market and still need a boost in kinetics to match the high energy density demand of applications.Perovskites have attracted the scientific community's attention in the last decade due to their electrocatalytic activity,chemical and structural properties,tunability,low cost,and scalability.Efforts have been made to understand the active sites and the operational mechanisms in perovskite oxides to shape them as an electrocatalyst in advanced energy devices.Understanding the role of perovskites is the key to engineering more controlled and efficient electrocatalysts via chemical synthesis,and there is still much to do.This review highlights the use of perovskites in different energy storage and conversion systems.The A,B,and A&B doping-site effects are analyzed to understand the opportunities and challenges related to this class of materials.In addition,the synthesis methods and the properties related to the doping site are described and summarized.展开更多
Low-level radio frequency(LLRF)systems stabilize the electromagnetic field in the RF cavities used for beam acceleration in particle accelerators.Reliable,accurate,and precise detection of RF amplitude and phase is pa...Low-level radio frequency(LLRF)systems stabilize the electromagnetic field in the RF cavities used for beam acceleration in particle accelerators.Reliable,accurate,and precise detection of RF amplitude and phase is particularly important to achieve high field stability for pulsed accelerators of free-electron lasers(FEL).The digital LLRF systems employ analog-to-digital converters to sample the frequency down-converted RF signal and use digital demodulation algorithms to calculate the RF amplitude and phase.Different sampling strategies and demodulation algorithms have been developed for these purposes and are introduced in this paper.This article focuses on advanced topics concerning RF detection,including accurate RF transient measurement,wideband RF detection,and RF detection with an asynchronous trigger,local oscillator,or clock.The analysis is based on the SwissFEL measurements,but the algorithms introduced are general for RF signal detection in particle accelerators.展开更多
A fast, reliable and precise method for the determination of Ba, Zr, Th, U, La, Ce, Eu, Hf and Gd in leaching solutions containing up to 1 mol/L FeCl3 by inductively coupled plasma-atomic emission spectrometry（ICP-AE...A fast, reliable and precise method for the determination of Ba, Zr, Th, U, La, Ce, Eu, Hf and Gd in leaching solutions containing up to 1 mol/L FeCl3 by inductively coupled plasma-atomic emission spectrometry（ICP-AES） was described.Liquid-liquid extraction with diethyl ether was applied for selective and quantitative extraction of the iron with a decontamination factor of 65000.The study has enabled the determination of rare earth elements, U, Th Ba, and Zr, from the solution with high iron content with detection limits in the range of 1-24 ng/ml and a precision of 0.9%-4.6 % relative standard deviation.The developed method was simple and was adopted for implementation in a glove box for handling radioactive materials.展开更多
In this work,we explore the use of an iterative Bayesian Monte Carlo(iBMC)method for nuclear data evaluation within a TALYS Evaluated Nuclear Data Library(TENDL)framework.The goal is to probe the model and parameter s...In this work,we explore the use of an iterative Bayesian Monte Carlo(iBMC)method for nuclear data evaluation within a TALYS Evaluated Nuclear Data Library(TENDL)framework.The goal is to probe the model and parameter space of the TALYS code system to find the optimal model and parameter sets that reproduces selected experimental data.The method involves the simultaneous variation of many nuclear reaction models as well as their parameters included in the TALYS code.The‘best’model set with its parameter set was obtained by comparing model calculations with selected experimental data.Three experimental data types were used:(1)reaction cross sections,(2)residual production cross sections,and(3)the elastic angular distributions.To improve our fit to experimental data,we update our‘best’parameter set—the file that maximizes the likelihood function—in an iterative fashion.Convergence was determined by monitoring the evolution of the maximum likelihood estimate(MLE)values and was considered reached when the relative change in the MLE for the last two iterations was within 5%.Once the final‘best’file is identified,we infer parameter uncertainties and covariance information to this file by varying model parameters around this file.In this way,we ensured that the parameter distributions are centered on our evaluation.The proposed method was applied to the evaluation of p+^(59)Co between 1 and 100 MeV.Finally,the adjusted files were compared with experimental data from the EXFOR database as well as with evaluations from the TENDL-2019,JENDL/He-2007 and JENDL-4.0/HE nuclear data libraries.展开更多
Swiss FEL is a free electron laser(FEL) under commissioning at the Paul Scherrer Institut(PSI) in Switzerland. Digital low-level RF(LLRF) systems are used in Swiss FEL to control more than 30 RF stations with either s...Swiss FEL is a free electron laser(FEL) under commissioning at the Paul Scherrer Institut(PSI) in Switzerland. Digital low-level RF(LLRF) systems are used in Swiss FEL to control more than 30 RF stations with either standing wave cavities(e.g. RF gun) or travelling wave structures working at different frequencies. After conditioned to desired power levels, the RF stations need to be setup for beam operation and the LLRF parameters need to be optimized for maximizing the beam stability. Several beam-based algorithms were developed to facilitate the setup, calibration and optimization of the Swiss FEL RF stations for beam operation. The algorithms were implemented as automation procedures in the framework of Experimental Physics and Industrial Control System(EPICS) and were used in commissioning and daily operation of Swiss FEL. In this paper, the algorithms and the implementation will be introduced together with the test results during the commissioning of SwissFEL.展开更多
The compressive deformation behavior of the extruded WZ42(Mg98.5Y1Zn0.5 in at.%)magnesium alloy containing a low amount of long-period stacking ordered(LPSO)phase was studied by in-situ synchrotron radiation diffracti...The compressive deformation behavior of the extruded WZ42(Mg98.5Y1Zn0.5 in at.%)magnesium alloy containing a low amount of long-period stacking ordered(LPSO)phase was studied by in-situ synchrotron radiation diffraction technique.Tests were conducted at temperatures between room temperature and 350℃.Detailed microstructure investigation was provided by scanning electron microscopy,particularly the backscattered electron imaging and electron backscatter diffraction technique.The results show that twinning lost its dominance and kinking of the LPSO phase became more pronounced with increasing deformation temperature.No cracks of the LPSO phase and no debonding r at the interface between the LPSO phase and the Mg matrix were observed at temperatures above 200℃.At 350℃,the LPSO phase lost its strengthening effect and the deformation of the alloy was mainly realized by the dynamic recrystallization of the Mg matrix.展开更多
基金support from FAPESP (Sao Paulo Research Foundation,Grant Numbers 2014/02163-7,2017/11958-1,2020/14968-0)CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico,301486/2016-6)the support given by ANP (Brazil’s National Oil,Natural Gas and Biofuels Agency)through the R&D levy regulation。
文摘Batteries,fuel cells,and supercapacitors are electrochemical devices already on the market and still need a boost in kinetics to match the high energy density demand of applications.Perovskites have attracted the scientific community's attention in the last decade due to their electrocatalytic activity,chemical and structural properties,tunability,low cost,and scalability.Efforts have been made to understand the active sites and the operational mechanisms in perovskite oxides to shape them as an electrocatalyst in advanced energy devices.Understanding the role of perovskites is the key to engineering more controlled and efficient electrocatalysts via chemical synthesis,and there is still much to do.This review highlights the use of perovskites in different energy storage and conversion systems.The A,B,and A&B doping-site effects are analyzed to understand the opportunities and challenges related to this class of materials.In addition,the synthesis methods and the properties related to the doping site are described and summarized.
文摘Low-level radio frequency(LLRF)systems stabilize the electromagnetic field in the RF cavities used for beam acceleration in particle accelerators.Reliable,accurate,and precise detection of RF amplitude and phase is particularly important to achieve high field stability for pulsed accelerators of free-electron lasers(FEL).The digital LLRF systems employ analog-to-digital converters to sample the frequency down-converted RF signal and use digital demodulation algorithms to calculate the RF amplitude and phase.Different sampling strategies and demodulation algorithms have been developed for these purposes and are introduced in this paper.This article focuses on advanced topics concerning RF detection,including accurate RF transient measurement,wideband RF detection,and RF detection with an asynchronous trigger,local oscillator,or clock.The analysis is based on the SwissFEL measurements,but the algorithms introduced are general for RF signal detection in particle accelerators.
基金supported by the Program "Training and Researchers" of the European Commission
文摘A fast, reliable and precise method for the determination of Ba, Zr, Th, U, La, Ce, Eu, Hf and Gd in leaching solutions containing up to 1 mol/L FeCl3 by inductively coupled plasma-atomic emission spectrometry（ICP-AES） was described.Liquid-liquid extraction with diethyl ether was applied for selective and quantitative extraction of the iron with a decontamination factor of 65000.The study has enabled the determination of rare earth elements, U, Th Ba, and Zr, from the solution with high iron content with detection limits in the range of 1-24 ng/ml and a precision of 0.9%-4.6 % relative standard deviation.The developed method was simple and was adopted for implementation in a glove box for handling radioactive materials.
基金Funding Open Access funding provided by Lib4RI–Library for the Research Institutes within the ETH Domain:Eawag,Empa,PSI&WSLthe Paul Scherrer Institute through the NES/GFA-ABE Cross Project.
文摘In this work,we explore the use of an iterative Bayesian Monte Carlo(iBMC)method for nuclear data evaluation within a TALYS Evaluated Nuclear Data Library(TENDL)framework.The goal is to probe the model and parameter space of the TALYS code system to find the optimal model and parameter sets that reproduces selected experimental data.The method involves the simultaneous variation of many nuclear reaction models as well as their parameters included in the TALYS code.The‘best’model set with its parameter set was obtained by comparing model calculations with selected experimental data.Three experimental data types were used:(1)reaction cross sections,(2)residual production cross sections,and(3)the elastic angular distributions.To improve our fit to experimental data,we update our‘best’parameter set—the file that maximizes the likelihood function—in an iterative fashion.Convergence was determined by monitoring the evolution of the maximum likelihood estimate(MLE)values and was considered reached when the relative change in the MLE for the last two iterations was within 5%.Once the final‘best’file is identified,we infer parameter uncertainties and covariance information to this file by varying model parameters around this file.In this way,we ensured that the parameter distributions are centered on our evaluation.The proposed method was applied to the evaluation of p+^(59)Co between 1 and 100 MeV.Finally,the adjusted files were compared with experimental data from the EXFOR database as well as with evaluations from the TENDL-2019,JENDL/He-2007 and JENDL-4.0/HE nuclear data libraries.
文摘Swiss FEL is a free electron laser(FEL) under commissioning at the Paul Scherrer Institut(PSI) in Switzerland. Digital low-level RF(LLRF) systems are used in Swiss FEL to control more than 30 RF stations with either standing wave cavities(e.g. RF gun) or travelling wave structures working at different frequencies. After conditioned to desired power levels, the RF stations need to be setup for beam operation and the LLRF parameters need to be optimized for maximizing the beam stability. Several beam-based algorithms were developed to facilitate the setup, calibration and optimization of the Swiss FEL RF stations for beam operation. The algorithms were implemented as automation procedures in the framework of Experimental Physics and Industrial Control System(EPICS) and were used in commissioning and daily operation of Swiss FEL. In this paper, the algorithms and the implementation will be introduced together with the test results during the commissioning of SwissFEL.
基金The authors acknowledge the Deutsches Elektronen-Synchrotron for the provision of facilities within the framework of the proposal I-20170459 ECThe authors are also grateful for support from the Grant Agency of the Charles University,grant number 1262217+3 种基金the grant SVV-2019-260442the Czech Science Foundation under grant 17-21855Sthe Operational Programme Research,Development and Education,The Ministry of Education,Youth and Sports(OP RDE,MEYS),grant number CZ.02.1.01/0.0/0.0/16_013/0001794GG thanks the support of the Spanish Ministry of Economy and Competitiveness,grant number MAT2016-78850-R.
文摘The compressive deformation behavior of the extruded WZ42(Mg98.5Y1Zn0.5 in at.%)magnesium alloy containing a low amount of long-period stacking ordered(LPSO)phase was studied by in-situ synchrotron radiation diffraction technique.Tests were conducted at temperatures between room temperature and 350℃.Detailed microstructure investigation was provided by scanning electron microscopy,particularly the backscattered electron imaging and electron backscatter diffraction technique.The results show that twinning lost its dominance and kinking of the LPSO phase became more pronounced with increasing deformation temperature.No cracks of the LPSO phase and no debonding r at the interface between the LPSO phase and the Mg matrix were observed at temperatures above 200℃.At 350℃,the LPSO phase lost its strengthening effect and the deformation of the alloy was mainly realized by the dynamic recrystallization of the Mg matrix.
