Decomposition processes of the quenched Zn-Al alloys were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities o...Decomposition processes of the quenched Zn-Al alloys were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (SSS) of Zn-Al alloy and α' phase formed by quenching would reduce with the increase of Zn content and the precipitation of η-Zn phases even when aging at ambient temperature, so that the exothermic precipitation peak in DSC curve would disappear. The activation energy of the η-Zn precipitation and the reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-Zn formation was determined by XRD. The microstructure change during aging was observed by TEM.展开更多
X-ray powder diffraction data and crystal structure of NiSbY compound were studied by X-ray powderdiffraction. The compound belongs to the space group F43 m with MgAgAs structure type, and the parameters Z=4, a=0.6307...X-ray powder diffraction data and crystal structure of NiSbY compound were studied by X-ray powderdiffraction. The compound belongs to the space group F43 m with MgAgAs structure type, and the parameters Z=4, a=0.63075(2) nm.展开更多
The compound PrNiSn was studied by X ray powder diffraction technique. The crystal structure and the X ray diffraction data for this compound at room temperature were reported. The compound PrNiSn is orthorhombic wi...The compound PrNiSn was studied by X ray powder diffraction technique. The crystal structure and the X ray diffraction data for this compound at room temperature were reported. The compound PrNiSn is orthorhombic with lattice parameters a =0.74569(3) nm, b =0.76851(5) nm, c =0.45676(8) nm, V =0.26176 nm 3, Z =4 and D x=8.076 g·cm -3 , space group Pna2 1(33). The figure of merit F N for the compound is F 30 =54 (0.0093, 60).展开更多
The research on the application of X-ray diffraction in the quantitative analysis of Chinese medicines is rare. The main reason is that the technical problems related to the internal standard and the selection of quan...The research on the application of X-ray diffraction in the quantitative analysis of Chinese medicines is rare. The main reason is that the technical problems related to the internal standard and the selection of quantitative peaks are not well solved, and the accuracy and precision of the results are not satisfactory. This study employed the concept of mass absorption coefficient based on the internal standard method, and the full spectrum fitting and quantitative methods were used to solve the above technical problems. The sample was blended. the internal standard substance of zinc oxide was fully ground, and tablets were prepared by positive pressure method. Under certain instrumental conditions, the PXRD pattern was obtained by scanning. The percentage of gypsum fibrosum in Xiaokening tablet was obtained by quantitative analysis of full spectrum fitting internal standard by TOPAS software. The method was investigated by methodology. At the same time, the method was compared by ion chromatography, and SPSS software was used to make a significant t test on the results of the two methods. After the investigation, the average standard recovery rate of CaSO4-2H2O was 99.06%(RSD = 3.02%);and the recovery rate for simulated samples was 96.7%. The method had good specificity. After statistical analysis, there was no significant difference between the new PXRD method and the traditional method of ion chromatography.展开更多
X-ray free-electron lasers(XFELs)can generate bright X-ray pulses with short durations and narrow bandwidths,leading to extensive applica-tions in many disciplines such as biology,materials science,and ultrafast scien...X-ray free-electron lasers(XFELs)can generate bright X-ray pulses with short durations and narrow bandwidths,leading to extensive applica-tions in many disciplines such as biology,materials science,and ultrafast science.Recently,there has been a growing demand for X-ray pulses with high photon energy,especially from developments in“diffraction-before-destruction”applications and in dynamic mesoscale materials science.Here,we propose utilizing the electron beams at XFELs to drive a meter-scale two-bunch plasma wakefield accelerator and double the energy of the accelerated beam in a compact and inexpensive way.Particle-in-cell simulations are performed to study the beam quality degradation under different beam loading scenarios and nonideal issues,and the results show that more than half of the accelerated beam can meet the requirements of XFELs.After its transport to the undulator,the accelerated beam can improve the photon energy to 22 keV by a factor of around four while maintaining the peak power,thus offering a promising pathway toward high-photon-energy XFELs.展开更多
The compound CeNi 5Sn was studied by means of X ray powder diffraction technique and refined by Rietveld method. It has a hexagonal structure with space group P 6 3/ mmc (No.194), Z =4, the lattice constant...The compound CeNi 5Sn was studied by means of X ray powder diffraction technique and refined by Rietveld method. It has a hexagonal structure with space group P 6 3/ mmc (No.194), Z =4, the lattice constants a =0 48912(3) nm, c =1 973(2) nm and D x=8 974 g·cm -3 . The Rietveld structural refinement was performed, leading to R p=0 138 and R wp =0 185. The figure of merit F N for the XRD data is F 30 =82 1(0 0068, 54). The X ray powder diffraction data are presented.展开更多
There are two kinds of China- made X- ray thickness gaugemeters i.e. dual beam- dual detector system and single beam- single detector system- SM series, the latter is used dominantly in Chinese steel industries. The p...There are two kinds of China- made X- ray thickness gaugemeters i.e. dual beam- dual detector system and single beam- single detector system- SM series, the latter is used dominantly in Chinese steel industries. The performance comparison between domestic and foreign instruments as well as its developments and applications is presented in this paper.展开更多
To evaluate the residual stress in TiAl based alloys by X ray diffraction, X ray elastic constants (REC) of a γ TiAl alloy were determined. From these results, the stress state of a given phase in a duplex TiAl based...To evaluate the residual stress in TiAl based alloys by X ray diffraction, X ray elastic constants (REC) of a γ TiAl alloy were determined. From these results, the stress state of a given phase in a duplex TiAl based alloy under a uniaxial tensile loading has been characterized by X ray diffraction. The results show that the X ray elastic constants and the microscopic stresses of the given phase are different from the apparent elastic constants and the macroscopic stresses of the alloy. The reason of the different distribution of the alloy was also discussed. [展开更多
Machine learning is attracting surging interest across nearly all scientific areas by enabling the analysis of large datasets and the extraction of scientific information from incomplete data.Data-driven science is ra...Machine learning is attracting surging interest across nearly all scientific areas by enabling the analysis of large datasets and the extraction of scientific information from incomplete data.Data-driven science is rapidly growing,especially in X-ray methodologies,where advanced light sources and detection technologies produce vast amounts of data that exceed meticulous human inspection capabilities.Despite the increasing demands,the full application of machine learning has been hindered by the need for data-specific optimizations.In this study,we introduce a new deep-learning-based phase retrieval method for imperfect diffraction data.This method provides robust phase retrieval for simulated data and performs well on partially damaged and noisy single-pulse diffraction data from X-ray free-electron lasers.Moreover,the method significantly reduces data processing time,facilitating real-time image reconstructions that are crucial for high-repetition-rate data acquisition.This approach offers a reliable solution to the phase problem to be widely adopted across various research areas confronting the inverse problem.展开更多
Photoelectron diffraction(PED)is a powerful technique for resolving surface structures with subangstrom precision.At high photon energies,angle-resolved photoemission spectroscopy(ARPES)reveals PED effects,often chall...Photoelectron diffraction(PED)is a powerful technique for resolving surface structures with subangstrom precision.At high photon energies,angle-resolved photoemission spectroscopy(ARPES)reveals PED effects,often challenged by small cross-sections,momentum transfer,and phonon scattering.X-ray PED(XPD)is not only an advantageous approach but also exhibits unexpected effects.We present a PED implementation for the spin-polarized relativistic Korringa-Kohn-Rostoker(SPRKKR)package to disentangle them,employing multiple scattering theory and a one-step photoemission model.Unlike conventional real-space approaches,our method uses a k-space formulation via the layer-KKR method,offering efficient and accurate calculations across a wide energy range(20-8000 eV)without angular momentum or cluster size convergence issues.Additionally,the alloy analogymodel enables simulations of finite-temperature XPDand effects in soft/hard X-ray ARPES.Applications includemodeling circular dichroism in angular distributions(CDAD)in core-level photoemission of Si(100)2p and Ge(100)3p,excited by 6000 eV photons with circular polarization.展开更多
Visualization of internal deformation fields in crystalline materials helps bridge the gap between theoretical models and practical applications.Applying Bragg coherent diffraction imaging under X-ray dynamical diffra...Visualization of internal deformation fields in crystalline materials helps bridge the gap between theoretical models and practical applications.Applying Bragg coherent diffraction imaging under X-ray dynamical diffraction conditions provides a promising approach to the longstanding challenge of investigating the deformation fields in micron-sized crystals.Here,we present an automatic differentiation-based reconstruction method that integrates dynamical scattering theory to accurately reconstruct deformation fields in large crystals.Using this forward model,our simulated and experimental results demonstrate that three-dimensional local strain information inside a large crystal can be accurately reconstructed under coherent X-ray dynamical diffraction conditions with Bragg coherent X-ray diffraction imaging.These findings open an avenue for extending the investigation of local deformation fields to microscale crystals while maintaining nanoscale resolution,leveraging the enhanced coherence and brightness of advanced X-ray sources.展开更多
This paper introduces a deep learning (DL)-based method for phase retrieval tailored to single-shot, multiple-frame coherent X-ray diffraction imaging (CXDI), designed specifically for visualizing local nanostructural...This paper introduces a deep learning (DL)-based method for phase retrieval tailored to single-shot, multiple-frame coherent X-ray diffraction imaging (CXDI), designed specifically for visualizing local nanostructural dynamics within a larger sample. Current phase retrieval methods often struggle with achieving high spatiotemporal resolutions, handling dynamic imaging, and managing computational costs, which limits their applicability in observing nanostructural dynamics. This study addresses these gaps by developing a novel method that leverages a feedforward architecture with a physics-informed strategy utilizing measurement settings, enabling the reconstruction of dynamic “movies" from time-evolving diffraction images of the illuminated area. The method incorporates key enhancements, such as temporal convolution blocks to capture spatiotemporal correlations and a unified TV regularization applied to the reconstructed object, resulting in improved noise reduction and spatial smoothness. An expanded evaluation framework, including multiple metrics and systematic sensitivity analysis, is employed to comprehensively assess the method’s performance and robustness. Proof-of-concept experiments, including numerical simulations and imaging experiments of a moving Ta test chart and colloidal gold particles (dispersed in aqueous polyvinyl alcohol solutions) with synchrotron hard X-rays, validate the high imaging performance of this method. Experimental results demonstrate that structures in the sample have been successfully reconstructed at short exposure times, significantly outperforming both traditional methods and current DL-based methods. The proposed method provides efficient and reliable reconstruction of dynamic images with low computational costs, making it suitable for exploring fast-evolving phenomena in synchrotron- or free-electron laser-based applications requiring high spatiotemporal resolutions.展开更多
Combinatorial synthesis and high-throughput characterization have become powerful tools to accelerate the discovery and design of novel materials.Correctly extracting information about the constituent phases and gaini...Combinatorial synthesis and high-throughput characterization have become powerful tools to accelerate the discovery and design of novel materials.Correctly extracting information about the constituent phases and gaining materials insight from high-throughput X-ray diffraction data of combinatorial libraries is a crucial step in establishing the composition–structure–property relationship.Basic information includes the number,identity,and fraction of present phases in all the samples,while advanced information includes the lattice change,texture information,solid solution behavior,etc.Encoding domain-specific knowledge,such as crystallography,X-ray diffraction,thermodynamics,kinetics,and solid-state chemistry,into automated algorithms is crucial for the development of automated phase mapping algorithms.In this study,we present an unsupervised optimization-based solver to tackle the phase mapping challenge in high-throughput X-ray diffraction datasets.Besides leveraging robust fitting abilities of neural-network optimization algorithms,we integrated various material information,including first-principles calculated thermodynamic data,crystallography,X-ray diffraction,and texture into our automated solver.Our approach exhibits robust performance across multiple experimental datasets.We emphasize the importance of correctly integrating material information for automated solvers,contributing to the development of future automated characterization tools.展开更多
A series of GaAs/InAs/GaAs samples were studied by double crystal X ray diffraction and the X ray dynamic theory was used to analyze the X ray diffraction results. As the thickness of InAs layer exceeds 1.7 monolayer,...A series of GaAs/InAs/GaAs samples were studied by double crystal X ray diffraction and the X ray dynamic theory was used to analyze the X ray diffraction results. As the thickness of InAs layer exceeds 1.7 monolayer, 3 dimensional InAs islands appear. Pendellosung fringes shifted. A multilayer structure model is proposed to describe the strain status in the InAs islands of the sample and a good agreement is obtained between the experimental and theoretical curves.展开更多
The crystal structure of new compound Ba 3BPO 7 has been solved by X ray powder diffraction technique. As a new structure type, the positions of barium, boron and phosphate atoms have been determined by single crystal...The crystal structure of new compound Ba 3BPO 7 has been solved by X ray powder diffraction technique. As a new structure type, the positions of barium, boron and phosphate atoms have been determined by single crystal direct method after profile decomposition from Ba 3BPO 7 X ray powder diffraction patterns. The positions of oxygen atoms have been determined by the interpretation of their vibration spectra which indicate that in this crystal the boron and phosphorus atoms form BO 3 and PO 4 polyhedra. The structure has been refined by Rietveld technique based on the above model.展开更多
Structural determination plays a pivotal role in chemical research by providing detailed insights into molecular architecture and functionality.Single-crystal X-ray diffraction(SCXRD)is widely regarded as the premier ...Structural determination plays a pivotal role in chemical research by providing detailed insights into molecular architecture and functionality.Single-crystal X-ray diffraction(SCXRD)is widely regarded as the premier technique for achieving precise three-dimensional structural elucidation[1].The persistent challenge of determining atomic-level structures for non-crystalline or conformationally flexible molecules has driven transformative innovations in crystallographic methodologies[2-5].展开更多
High-pressure research has emerged as a pivotal approach for advancing our understanding and development of optoelectronic materials,which are vital for a wide range of applications,including photovoltaics,light-emitt...High-pressure research has emerged as a pivotal approach for advancing our understanding and development of optoelectronic materials,which are vital for a wide range of applications,including photovoltaics,light-emitting devices,and photodetectors.This review highlights various in situ characterization methods employed in high-pressure research to investigate the optical,electronic,and structural properties of optoelectronic materials.We explore the advances that have been made in techniques such as X-ray diffraction,absorption spectroscopy,nonlinear optics,photoluminescence spectroscopy,Raman spectroscopy,and photoresponse measurement,emphasizing how these methods have enhanced the elucidation of structural transitions,bandgap modulation,performance optimization,and carrier dynamics engineering.These insights underscore the pivotal role of high-pressure techniques in optimizing and tailoring optoelectronic materials for future applications.展开更多
文摘Decomposition processes of the quenched Zn-Al alloys were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (SSS) of Zn-Al alloy and α' phase formed by quenching would reduce with the increase of Zn content and the precipitation of η-Zn phases even when aging at ambient temperature, so that the exothermic precipitation peak in DSC curve would disappear. The activation energy of the η-Zn precipitation and the reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-Zn formation was determined by XRD. The microstructure change during aging was observed by TEM.
文摘X-ray powder diffraction data and crystal structure of NiSbY compound were studied by X-ray powderdiffraction. The compound belongs to the space group F43 m with MgAgAs structure type, and the parameters Z=4, a=0.63075(2) nm.
文摘The compound PrNiSn was studied by X ray powder diffraction technique. The crystal structure and the X ray diffraction data for this compound at room temperature were reported. The compound PrNiSn is orthorhombic with lattice parameters a =0.74569(3) nm, b =0.76851(5) nm, c =0.45676(8) nm, V =0.26176 nm 3, Z =4 and D x=8.076 g·cm -3 , space group Pna2 1(33). The figure of merit F N for the compound is F 30 =54 (0.0093, 60).
文摘The research on the application of X-ray diffraction in the quantitative analysis of Chinese medicines is rare. The main reason is that the technical problems related to the internal standard and the selection of quantitative peaks are not well solved, and the accuracy and precision of the results are not satisfactory. This study employed the concept of mass absorption coefficient based on the internal standard method, and the full spectrum fitting and quantitative methods were used to solve the above technical problems. The sample was blended. the internal standard substance of zinc oxide was fully ground, and tablets were prepared by positive pressure method. Under certain instrumental conditions, the PXRD pattern was obtained by scanning. The percentage of gypsum fibrosum in Xiaokening tablet was obtained by quantitative analysis of full spectrum fitting internal standard by TOPAS software. The method was investigated by methodology. At the same time, the method was compared by ion chromatography, and SPSS software was used to make a significant t test on the results of the two methods. After the investigation, the average standard recovery rate of CaSO4-2H2O was 99.06%(RSD = 3.02%);and the recovery rate for simulated samples was 96.7%. The method had good specificity. After statistical analysis, there was no significant difference between the new PXRD method and the traditional method of ion chromatography.
基金supported by the National Grand Instrument Project No. SQ2019YFF01014400the Natural Science Foundation of China (Grant Nos. 12375147, 12435011, 12075030)+2 种基金the Beijing Outstanding Young Scientist Project, Project for Young Scientists in Basic Research of Chinese Academy of Sciences (YSBR-115)the Beijing Normal University Scientific Research Initiation Fund for Introducing Talents No. 310432104the Fundamental Research Funds for the Central Universities, Peking University
文摘X-ray free-electron lasers(XFELs)can generate bright X-ray pulses with short durations and narrow bandwidths,leading to extensive applica-tions in many disciplines such as biology,materials science,and ultrafast science.Recently,there has been a growing demand for X-ray pulses with high photon energy,especially from developments in“diffraction-before-destruction”applications and in dynamic mesoscale materials science.Here,we propose utilizing the electron beams at XFELs to drive a meter-scale two-bunch plasma wakefield accelerator and double the energy of the accelerated beam in a compact and inexpensive way.Particle-in-cell simulations are performed to study the beam quality degradation under different beam loading scenarios and nonideal issues,and the results show that more than half of the accelerated beam can meet the requirements of XFELs.After its transport to the undulator,the accelerated beam can improve the photon energy to 22 keV by a factor of around four while maintaining the peak power,thus offering a promising pathway toward high-photon-energy XFELs.
文摘The compound CeNi 5Sn was studied by means of X ray powder diffraction technique and refined by Rietveld method. It has a hexagonal structure with space group P 6 3/ mmc (No.194), Z =4, the lattice constants a =0 48912(3) nm, c =1 973(2) nm and D x=8 974 g·cm -3 . The Rietveld structural refinement was performed, leading to R p=0 138 and R wp =0 185. The figure of merit F N for the XRD data is F 30 =82 1(0 0068, 54). The X ray powder diffraction data are presented.
文摘There are two kinds of China- made X- ray thickness gaugemeters i.e. dual beam- dual detector system and single beam- single detector system- SM series, the latter is used dominantly in Chinese steel industries. The performance comparison between domestic and foreign instruments as well as its developments and applications is presented in this paper.
文摘To evaluate the residual stress in TiAl based alloys by X ray diffraction, X ray elastic constants (REC) of a γ TiAl alloy were determined. From these results, the stress state of a given phase in a duplex TiAl based alloy under a uniaxial tensile loading has been characterized by X ray diffraction. The results show that the X ray elastic constants and the microscopic stresses of the given phase are different from the apparent elastic constants and the macroscopic stresses of the alloy. The reason of the different distribution of the alloy was also discussed. [
基金supported by the National Research Foundation of Korea(Grant Nos.RS-2022-NR068223 and RS-2024-00346711).
文摘Machine learning is attracting surging interest across nearly all scientific areas by enabling the analysis of large datasets and the extraction of scientific information from incomplete data.Data-driven science is rapidly growing,especially in X-ray methodologies,where advanced light sources and detection technologies produce vast amounts of data that exceed meticulous human inspection capabilities.Despite the increasing demands,the full application of machine learning has been hindered by the need for data-specific optimizations.In this study,we introduce a new deep-learning-based phase retrieval method for imperfect diffraction data.This method provides robust phase retrieval for simulated data and performs well on partially damaged and noisy single-pulse diffraction data from X-ray free-electron lasers.Moreover,the method significantly reduces data processing time,facilitating real-time image reconstructions that are crucial for high-repetition-rate data acquisition.This approach offers a reliable solution to the phase problem to be widely adopted across various research areas confronting the inverse problem.
基金supported by the project Quantum materials for applications in sustainable technologies(QM4ST),funded as project No.CZ.02.01.01/00/22_008/0004572 by Program Johannes Amos Commenius,call Excellent Research(T.-P.V.,J.M.,A.P.)the Czech Science Foundation Grant No.GAČR 23-04746S(T.-P.V.)+3 种基金In addition,T.-P.V.,S.T.,D.S.,A.P.,and J.M.acknowledge partial funding from Horizon Europe MSCA Doctoral network grant n.101073486,EUSpecLab,funded by the European UnionThis work was also supported by the Deutsche Forschungsgemeinschaft,Grant No.TRR288–422213477(Project B04)by the Federal Ministry of Education and Research(BMBF,Project 05K22UM2)A.W.was supported by the Polish National Science Center(NCN),grant no.2020/37/B/ST5/03669.
文摘Photoelectron diffraction(PED)is a powerful technique for resolving surface structures with subangstrom precision.At high photon energies,angle-resolved photoemission spectroscopy(ARPES)reveals PED effects,often challenged by small cross-sections,momentum transfer,and phonon scattering.X-ray PED(XPD)is not only an advantageous approach but also exhibits unexpected effects.We present a PED implementation for the spin-polarized relativistic Korringa-Kohn-Rostoker(SPRKKR)package to disentangle them,employing multiple scattering theory and a one-step photoemission model.Unlike conventional real-space approaches,our method uses a k-space formulation via the layer-KKR method,offering efficient and accurate calculations across a wide energy range(20-8000 eV)without angular momentum or cluster size convergence issues.Additionally,the alloy analogymodel enables simulations of finite-temperature XPDand effects in soft/hard X-ray ARPES.Applications includemodeling circular dichroism in angular distributions(CDAD)in core-level photoemission of Si(100)2p and Ge(100)3p,excited by 6000 eV photons with circular polarization.
基金Shanghai Advanced Research Institute was funded by the '100 Talents Project' of the Chinese Academy of SciencesWork at Brookhaven National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012704+1 种基金Measurements were conducted at the Advanced Photon Source (APS) beamline 34-ID-C, which was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357The beamline 34-ID-C was built with U.S. National Science Foundation grant DMR-9724294.
文摘Visualization of internal deformation fields in crystalline materials helps bridge the gap between theoretical models and practical applications.Applying Bragg coherent diffraction imaging under X-ray dynamical diffraction conditions provides a promising approach to the longstanding challenge of investigating the deformation fields in micron-sized crystals.Here,we present an automatic differentiation-based reconstruction method that integrates dynamical scattering theory to accurately reconstruct deformation fields in large crystals.Using this forward model,our simulated and experimental results demonstrate that three-dimensional local strain information inside a large crystal can be accurately reconstructed under coherent X-ray dynamical diffraction conditions with Bragg coherent X-ray diffraction imaging.These findings open an avenue for extending the investigation of local deformation fields to microscale crystals while maintaining nanoscale resolution,leveraging the enhanced coherence and brightness of advanced X-ray sources.
基金supported by the JSPS KAKENHI Grants 20K05301,JP19H05815,20K05068,and JP23H05403the JST-CREST Program(Innovative Measurement and Analysis),Japan.
文摘This paper introduces a deep learning (DL)-based method for phase retrieval tailored to single-shot, multiple-frame coherent X-ray diffraction imaging (CXDI), designed specifically for visualizing local nanostructural dynamics within a larger sample. Current phase retrieval methods often struggle with achieving high spatiotemporal resolutions, handling dynamic imaging, and managing computational costs, which limits their applicability in observing nanostructural dynamics. This study addresses these gaps by developing a novel method that leverages a feedforward architecture with a physics-informed strategy utilizing measurement settings, enabling the reconstruction of dynamic “movies" from time-evolving diffraction images of the illuminated area. The method incorporates key enhancements, such as temporal convolution blocks to capture spatiotemporal correlations and a unified TV regularization applied to the reconstructed object, resulting in improved noise reduction and spatial smoothness. An expanded evaluation framework, including multiple metrics and systematic sensitivity analysis, is employed to comprehensively assess the method’s performance and robustness. Proof-of-concept experiments, including numerical simulations and imaging experiments of a moving Ta test chart and colloidal gold particles (dispersed in aqueous polyvinyl alcohol solutions) with synchrotron hard X-rays, validate the high imaging performance of this method. Experimental results demonstrate that structures in the sample have been successfully reconstructed at short exposure times, significantly outperforming both traditional methods and current DL-based methods. The proposed method provides efficient and reliable reconstruction of dynamic images with low computational costs, making it suitable for exploring fast-evolving phenomena in synchrotron- or free-electron laser-based applications requiring high spatiotemporal resolutions.
基金the funding support from the Research Center for Industries of the Future(RCIF)from Westlake University,and computation resources from the High-Performance Computing Center(HPC)at Westlake UniversityS.G.and C.W.acknowledge the funding support from US AFOSR Multidisciplinary University Research Initiative(MURI)under award FA9550-18-1-0136T.L.was supported by funding from the Toyota Research Institute.The DFT calculations were performed on Quest computing facility at Northwestern University,which is jointly supported by the Office of the Provost,the Office for Research,and Northwestern University Information Technology.
文摘Combinatorial synthesis and high-throughput characterization have become powerful tools to accelerate the discovery and design of novel materials.Correctly extracting information about the constituent phases and gaining materials insight from high-throughput X-ray diffraction data of combinatorial libraries is a crucial step in establishing the composition–structure–property relationship.Basic information includes the number,identity,and fraction of present phases in all the samples,while advanced information includes the lattice change,texture information,solid solution behavior,etc.Encoding domain-specific knowledge,such as crystallography,X-ray diffraction,thermodynamics,kinetics,and solid-state chemistry,into automated algorithms is crucial for the development of automated phase mapping algorithms.In this study,we present an unsupervised optimization-based solver to tackle the phase mapping challenge in high-throughput X-ray diffraction datasets.Besides leveraging robust fitting abilities of neural-network optimization algorithms,we integrated various material information,including first-principles calculated thermodynamic data,crystallography,X-ray diffraction,and texture into our automated solver.Our approach exhibits robust performance across multiple experimental datasets.We emphasize the importance of correctly integrating material information for automated solvers,contributing to the development of future automated characterization tools.
文摘A series of GaAs/InAs/GaAs samples were studied by double crystal X ray diffraction and the X ray dynamic theory was used to analyze the X ray diffraction results. As the thickness of InAs layer exceeds 1.7 monolayer, 3 dimensional InAs islands appear. Pendellosung fringes shifted. A multilayer structure model is proposed to describe the strain status in the InAs islands of the sample and a good agreement is obtained between the experimental and theoretical curves.
文摘The crystal structure of new compound Ba 3BPO 7 has been solved by X ray powder diffraction technique. As a new structure type, the positions of barium, boron and phosphate atoms have been determined by single crystal direct method after profile decomposition from Ba 3BPO 7 X ray powder diffraction patterns. The positions of oxygen atoms have been determined by the interpretation of their vibration spectra which indicate that in this crystal the boron and phosphorus atoms form BO 3 and PO 4 polyhedra. The structure has been refined by Rietveld technique based on the above model.
文摘Structural determination plays a pivotal role in chemical research by providing detailed insights into molecular architecture and functionality.Single-crystal X-ray diffraction(SCXRD)is widely regarded as the premier technique for achieving precise three-dimensional structural elucidation[1].The persistent challenge of determining atomic-level structures for non-crystalline or conformationally flexible molecules has driven transformative innovations in crystallographic methodologies[2-5].
基金supported by the National Nature Science Foundation of China(NSFC)(Grant Nos.22275004,62274040,and 62304046)the Shanghai Science and Technology Committee(Grant No.22JC1410300)+2 种基金the Shanghai Key Laboratory of Novel Extreme Condition Materials(Grant No.22dz2260800)the National Key Research and Development Program of China(Grant No.2022YFE0137400)the Shanghai Science and Technology Innovationaction Plan(Grant No.24DZ3001200).
文摘High-pressure research has emerged as a pivotal approach for advancing our understanding and development of optoelectronic materials,which are vital for a wide range of applications,including photovoltaics,light-emitting devices,and photodetectors.This review highlights various in situ characterization methods employed in high-pressure research to investigate the optical,electronic,and structural properties of optoelectronic materials.We explore the advances that have been made in techniques such as X-ray diffraction,absorption spectroscopy,nonlinear optics,photoluminescence spectroscopy,Raman spectroscopy,and photoresponse measurement,emphasizing how these methods have enhanced the elucidation of structural transitions,bandgap modulation,performance optimization,and carrier dynamics engineering.These insights underscore the pivotal role of high-pressure techniques in optimizing and tailoring optoelectronic materials for future applications.
