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
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
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
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
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
Objective:In addition to its positive benefits,caffeine also has harmful consequences.Therefore,it is essential to ascertain its content in various substances.Impact Statement:The present study emphasizes a novel way ...Objective:In addition to its positive benefits,caffeine also has harmful consequences.Therefore,it is essential to ascertain its content in various substances.Impact Statement:The present study emphasizes a novel way of quantification of caffeine in real as well as laboratory samples based on a nanomaterialassisted electrochemical technique.Introduction:Electrochemical sensing is a prominent analytical technique because of its efficiency,speed,and simple preparation and observations.Due to its low chemical potential,SnO_(2)(tin oxide)demonstrates rapid redox reactions when used as an electrode.The presence of shielded 4f levels contributes to its distinctive optical,catalytic,and electrochemical capabilities.Methods:An efficient coprecipitation approach,which is simple and rapid and operates at low temperatures,is utilized to produce zinc-doped tin oxide nanoparticles(Zn–SnO_(2)nanoparticles).Zinc doping is used to modify the optoelectronic characteristics of tin oxide nanoparticles,rendering them very efficient as electrochemical sensors.Results:The crystal structure of samples was analyzed using x-ray diffraction,electronic transitions were calculated using ultraviolet–visible spectroscopy,and surface morphology was analyzed using field emission scanning electron microscopy.The x-ray diffraction investigation revealed that the produced Zn-doped SnO2 nanoparticles exhibit tetragonal phases,and the average size of their crystallites reduces upon doping Zn with SnO2.The bandgap energy calculated using the Tauc plot was found to be 3.77 eV.Conclusion:The fabricated caffeine sensor exhibits a sensitivity of 0.605μAμM−1 cm−2,and its limit of detection was found to be 3μM.展开更多
Silicogermanate(JU110)with an interrupted open-framework has been synthesized by using a hydrothermal method using 1,1’-(1,4-phenylenebis(methylene))bis(1-methylpyrrolidin-1-ium)hydroxide as an organic structure-dire...Silicogermanate(JU110)with an interrupted open-framework has been synthesized by using a hydrothermal method using 1,1’-(1,4-phenylenebis(methylene))bis(1-methylpyrrolidin-1-ium)hydroxide as an organic structure-directing agent(OSDA).Silicon and fluoride anions were introduced to the concentrated-gel synthesis system,and different synthetic parameters influencing the synthesis were discussed.The structure of JU110 was characterised by using rotation electron diffraction(RED)and high-resolution powder X-ray diffraction.JU110 crystallizes in the space group Fm2m(No.42)with a=13.9117(2)Å,b=18.2980(3)Åand c=32.7800(6)Å.The structure is constructed by the sti layers found in the STI framework that are pillared by D4R/Ge7 units to form a large cavity,showing 10-ring openings along[100]and 9-ring openings along[110].Thermal stability studies showed that the framework was maintained with the loss of water molecules,but collapsed with the removal of charge-compensating cations.展开更多
Prussian blue(PB)and its analogues(PBAs)have recently attracted great interest resulting from their varied characteristics as functional materials.^(1)In 1996,a cyanide-bridged CoFe PBA,K_(0.2)Co_(1.4)[Fe(CN)_(6)]...Prussian blue(PB)and its analogues(PBAs)have recently attracted great interest resulting from their varied characteristics as functional materials.^(1)In 1996,a cyanide-bridged CoFe PBA,K_(0.2)Co_(1.4)[Fe(CN)_(6)]·6.9H_(2)O,was reported to show light-induced magnetization from a paramagnetic[ls-Co^(III)-ls-Fe^(II)]phase to a ferrimagnetic[hs-Co^(II)-ls-Fe^(III)]phase(ls=low spin and hs=high spin),where light-induced charge transfer from Fe^(II)to Co^(III)ions caused ls to hs transitions to occur in the Co ions at low temperatures.^(2)This behavior and its thermally induced equivalent are described as the electron transfer-coupled spin transition(ETCST).^(3)展开更多
Since the first discovery and description of materials,whose structures are not periodic,enormous efforts have been made in studying these aperiodic structures.With these efforts including the development of superspac...Since the first discovery and description of materials,whose structures are not periodic,enormous efforts have been made in studying these aperiodic structures.With these efforts including the development of superspace group theory and structure solution algorithms,numerous incommensurately modulated structures which represent the vast majority of known aperiodic structures have been determined with single crystal X-ray diffraction data.However,the determination of modulated structures remains very difficult for polycrystalline materials.Powder X-ray diffraction and electron microscopy techniques yield remarkable information for polycrystalline materials.By combining these two methods,modulated structures of polycrystalline materials that impede solution by conventional methods can be determined.The power of these methods is illustrated with the examples of the determination of modulated structures of polycrystalline materials.展开更多
The assembly–disassembly–organisation–reassembly (ADOR) approach extends the synthesis of new zeolites. Understanding the disassembly and organisation mechanism is important to optimise the post-treatment process o...The assembly–disassembly–organisation–reassembly (ADOR) approach extends the synthesis of new zeolites. Understanding the disassembly and organisation mechanism is important to optimise the post-treatment process on germanosilicate zeolites. In situ synchrotron X-ray diffraction technique was applied to study the mechanism of these two steps in HCl vapour,which it is often unfeasible to capture using conventional ex situ characterisation. Three germanosilicate zeolites with different pore systems,i.e. UTL,UOV and IWR,were selected as models to compare the reaction behaviours. Three key steps,including fast hydrolysis of d4r units (ca. 1 min),further disassembly (ca. 3–5 min),and self-organisation after disassembly (ca. 2–3 min),were observed in the HCl acid vapour. An unusual lattice expansion of the intralayer was observed at the very beginning of the hydrolysis process in IWR,while the UTL and UOV showed continuous shrinkage. Owing to the diffusion differences related to the structural features,extra-large-pore UTL zeolite showed faster kinetics than the other two large-pore zeolites,although UTL zeolite has much larger crystals. These findings potentially guide further modification of the treatment parameters in the ADOR process to prepare new zeolites.展开更多
The silicon-containing poly (amic acid)s were synthesized from bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride (SIDA), pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (4,4'-ODA) in N, N-dimethylacetam...The silicon-containing poly (amic acid)s were synthesized from bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride (SIDA), pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (4,4'-ODA) in N, N-dimethylacetamide (DMAc). The poly (amic acid) films were obtained by solution-cast method from DMAc solutions and thermally converted into transparent, flexible and tough polyimide films. The wide-angle X-ray diffraction diagrams revealed that all the polyimides possessed amorphous character, and the regulation of those polyimides were decreased with the increase of the molar ratio of SIDA to PMDA. Differential scanning calorimeter measurements showed that the introduction of SIDA to polyimide backbone would make glass transition temperature shift to lower temperature. Thermogravimetric analyses indicated that the silicon-containing polyimides lowered decomposition temperature as compared with PMDA/4, 4′-ODA polyimides. However, UV-visible transmission and reflection spectra showed that the optical transparency of silicon-containing polyimide thin films was superior to that of PMDA/4, 4'-ODA polyimide thin films.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
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
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
Industrial grade multi-walled carbon nanotubes(IG-MWCNTs) are a low-cost substitute for commercially purified multi-walled carbon nanotubes(P-MWCNTs). In this work, IG-MWCNTs were functionalized with tetraethylenepent...Industrial grade multi-walled carbon nanotubes(IG-MWCNTs) are a low-cost substitute for commercially purified multi-walled carbon nanotubes(P-MWCNTs). In this work, IG-MWCNTs were functionalized with tetraethylenepentamine(TEPA) for CO2capture. The TEPA impregnated IG-MWCNTs were characterized with various experimental methods including N2adsorption/desorption isotherms, elemental analysis, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. Both the adsorption isotherms of IGMWCNTs-n and the isosteric heats of different adsorption capacities were obtained from experiments. TEPA impregnated IG-MWCNTs were also shown to have high CO2adsorption capacity comparable to that of TEPA impregnated P-MWCNTs. The adsorption capacity of IG-MWCNTs based adsorbents was in the range of 2.145 to 3.088 mmol/g, depending on adsorption temperatures. Having the advantages of low-cost and high adsorption capacity, TEPA impregnated IG-MWCNTs seem to be a promising adsorbent for CO2capture from flue gas.展开更多
Gallium-titanium-zinc oxide(GTZO) transparent conducting oxide(TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic prope...Gallium-titanium-zinc oxide(GTZO) transparent conducting oxide(TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic properties of GTZO thin films on Ar gas pressure were observed. The X-ray diffraction(XRD) and scanning electron microscopy(SEM) results show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. With the increment of Ar gas pressure, the microstructure and optoelectronic properties of GTZO thin films will be changed. When Ar gas pressure is 0.4 Pa, the deposited films possess the best crystal quality and optoelectronic properties.展开更多
The residual stress in a 20%SiC w/6061Al composite as extruded was investigated by using X ray stress measurement method. It was found that, high residual stress existed in the composite and residual stress distributi...The residual stress in a 20%SiC w/6061Al composite as extruded was investigated by using X ray stress measurement method. It was found that, high residual stress existed in the composite and residual stress distribution in each direction are not uniform. Relaxation process of residual stress in the composite was dynamically measured during annealing at high temperature. It is verified that the relaxation of residual stress obeys the power law at high temperature. With the creep mechanism, the relaxation behavior of residual stresses at high temperature was analyzed. The results show that, the stress exponent and activation energy for stress relaxation of the composite are obviously higher than those of the matrix alloy.展开更多
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.
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Dr.Gaurav Bhanjana is thankful to CSIR,Government(Govt.)of India,for providing CSIR-SRA(No.B-12998 dated 2023 March 31)Mr.Ravinder Lamba is thankful to UGC,Govt.of India,for providing SRF vide letter number 1399/(CSIR-UGC NET JUNE 2019)dated 2019 December 16.Sandeep Kumar thanks Punjab Engineering College(Deemed to Be University)for providing a research initiation grant(No.PEC/DSR&IC/54 dated 2024 April 10)+1 种基金the Department of Science and Technology,Govt.of India,for a DST-PURSE grant(No.SR/PURSE/2024/350 dated 2024 October 14)The authors thank MoE,Govt.of India,for research grant vide letter no.SPARC/2019-2020/P2065/SL dated 2023 July 28.
文摘Objective:In addition to its positive benefits,caffeine also has harmful consequences.Therefore,it is essential to ascertain its content in various substances.Impact Statement:The present study emphasizes a novel way of quantification of caffeine in real as well as laboratory samples based on a nanomaterialassisted electrochemical technique.Introduction:Electrochemical sensing is a prominent analytical technique because of its efficiency,speed,and simple preparation and observations.Due to its low chemical potential,SnO_(2)(tin oxide)demonstrates rapid redox reactions when used as an electrode.The presence of shielded 4f levels contributes to its distinctive optical,catalytic,and electrochemical capabilities.Methods:An efficient coprecipitation approach,which is simple and rapid and operates at low temperatures,is utilized to produce zinc-doped tin oxide nanoparticles(Zn–SnO_(2)nanoparticles).Zinc doping is used to modify the optoelectronic characteristics of tin oxide nanoparticles,rendering them very efficient as electrochemical sensors.Results:The crystal structure of samples was analyzed using x-ray diffraction,electronic transitions were calculated using ultraviolet–visible spectroscopy,and surface morphology was analyzed using field emission scanning electron microscopy.The x-ray diffraction investigation revealed that the produced Zn-doped SnO2 nanoparticles exhibit tetragonal phases,and the average size of their crystallites reduces upon doping Zn with SnO2.The bandgap energy calculated using the Tauc plot was found to be 3.77 eV.Conclusion:The fabricated caffeine sensor exhibits a sensitivity of 0.605μAμM−1 cm−2,and its limit of detection was found to be 3μM.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFB0701100)the National Natural Science Foundation of China(Grant No.:21320102001 and 21621001)+2 种基金the 111 Project(B17020)financial support from the Swedish Research Council(VR),the Swedish Governmental Agency for Innovation Systems(VINNOVA)the Knut and Alice Wallenberg Foundation through the project grant 3DEM-NATUR.
文摘Silicogermanate(JU110)with an interrupted open-framework has been synthesized by using a hydrothermal method using 1,1’-(1,4-phenylenebis(methylene))bis(1-methylpyrrolidin-1-ium)hydroxide as an organic structure-directing agent(OSDA).Silicon and fluoride anions were introduced to the concentrated-gel synthesis system,and different synthetic parameters influencing the synthesis were discussed.The structure of JU110 was characterised by using rotation electron diffraction(RED)and high-resolution powder X-ray diffraction.JU110 crystallizes in the space group Fm2m(No.42)with a=13.9117(2)Å,b=18.2980(3)Åand c=32.7800(6)Å.The structure is constructed by the sti layers found in the STI framework that are pillared by D4R/Ge7 units to form a large cavity,showing 10-ring openings along[100]and 9-ring openings along[110].Thermal stability studies showed that the framework was maintained with the loss of water molecules,but collapsed with the removal of charge-compensating cations.
文摘Prussian blue(PB)and its analogues(PBAs)have recently attracted great interest resulting from their varied characteristics as functional materials.^(1)In 1996,a cyanide-bridged CoFe PBA,K_(0.2)Co_(1.4)[Fe(CN)_(6)]·6.9H_(2)O,was reported to show light-induced magnetization from a paramagnetic[ls-Co^(III)-ls-Fe^(II)]phase to a ferrimagnetic[hs-Co^(II)-ls-Fe^(III)]phase(ls=low spin and hs=high spin),where light-induced charge transfer from Fe^(II)to Co^(III)ions caused ls to hs transitions to occur in the Co ions at low temperatures.^(2)This behavior and its thermally induced equivalent are described as the electron transfer-coupled spin transition(ETCST).^(3)
基金supported by the Natural Science Foundation of China(21321001 and 21527803)the National Basic Research Program of China(2013CB8933402).
文摘Since the first discovery and description of materials,whose structures are not periodic,enormous efforts have been made in studying these aperiodic structures.With these efforts including the development of superspace group theory and structure solution algorithms,numerous incommensurately modulated structures which represent the vast majority of known aperiodic structures have been determined with single crystal X-ray diffraction data.However,the determination of modulated structures remains very difficult for polycrystalline materials.Powder X-ray diffraction and electron microscopy techniques yield remarkable information for polycrystalline materials.By combining these two methods,modulated structures of polycrystalline materials that impede solution by conventional methods can be determined.The power of these methods is illustrated with the examples of the determination of modulated structures of polycrystalline materials.
基金support from the BL14B station of the Shanghai Synchrotron Radiation Facility is sincerely acknowledged.This work was supported by the National Natural Science Foundation of China(no.12175235)supported by Charles University.M.O.acknowledges the Czech Science Foundation for supporting this work through project 20-12099S.
文摘The assembly–disassembly–organisation–reassembly (ADOR) approach extends the synthesis of new zeolites. Understanding the disassembly and organisation mechanism is important to optimise the post-treatment process on germanosilicate zeolites. In situ synchrotron X-ray diffraction technique was applied to study the mechanism of these two steps in HCl vapour,which it is often unfeasible to capture using conventional ex situ characterisation. Three germanosilicate zeolites with different pore systems,i.e. UTL,UOV and IWR,were selected as models to compare the reaction behaviours. Three key steps,including fast hydrolysis of d4r units (ca. 1 min),further disassembly (ca. 3–5 min),and self-organisation after disassembly (ca. 2–3 min),were observed in the HCl acid vapour. An unusual lattice expansion of the intralayer was observed at the very beginning of the hydrolysis process in IWR,while the UTL and UOV showed continuous shrinkage. Owing to the diffusion differences related to the structural features,extra-large-pore UTL zeolite showed faster kinetics than the other two large-pore zeolites,although UTL zeolite has much larger crystals. These findings potentially guide further modification of the treatment parameters in the ADOR process to prepare new zeolites.
文摘The silicon-containing poly (amic acid)s were synthesized from bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride (SIDA), pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (4,4'-ODA) in N, N-dimethylacetamide (DMAc). The poly (amic acid) films were obtained by solution-cast method from DMAc solutions and thermally converted into transparent, flexible and tough polyimide films. The wide-angle X-ray diffraction diagrams revealed that all the polyimides possessed amorphous character, and the regulation of those polyimides were decreased with the increase of the molar ratio of SIDA to PMDA. Differential scanning calorimeter measurements showed that the introduction of SIDA to polyimide backbone would make glass transition temperature shift to lower temperature. Thermogravimetric analyses indicated that the silicon-containing polyimides lowered decomposition temperature as compared with PMDA/4, 4′-ODA polyimides. However, UV-visible transmission and reflection spectra showed that the optical transparency of silicon-containing polyimide thin films was superior to that of PMDA/4, 4'-ODA polyimide thin films.
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.
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 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financially supported by the National Key Basic Research Program of China(No.2014CB643403)the National Science Fund for Distinguished Young Scholars(No.51225401)
基金supported by Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ12E08002)
文摘Industrial grade multi-walled carbon nanotubes(IG-MWCNTs) are a low-cost substitute for commercially purified multi-walled carbon nanotubes(P-MWCNTs). In this work, IG-MWCNTs were functionalized with tetraethylenepentamine(TEPA) for CO2capture. The TEPA impregnated IG-MWCNTs were characterized with various experimental methods including N2adsorption/desorption isotherms, elemental analysis, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. Both the adsorption isotherms of IGMWCNTs-n and the isosteric heats of different adsorption capacities were obtained from experiments. TEPA impregnated IG-MWCNTs were also shown to have high CO2adsorption capacity comparable to that of TEPA impregnated P-MWCNTs. The adsorption capacity of IG-MWCNTs based adsorbents was in the range of 2.145 to 3.088 mmol/g, depending on adsorption temperatures. Having the advantages of low-cost and high adsorption capacity, TEPA impregnated IG-MWCNTs seem to be a promising adsorbent for CO2capture from flue gas.
基金supported by the National Natural Science Foundation of China(No.11504436)the Natural Science Foundation of Hubei Province(No.2015CFB364)the Fundamental Research Funds for the Central Universities(Nos.CZW14019 and CZW15045)
文摘Gallium-titanium-zinc oxide(GTZO) transparent conducting oxide(TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic properties of GTZO thin films on Ar gas pressure were observed. The X-ray diffraction(XRD) and scanning electron microscopy(SEM) results show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. With the increment of Ar gas pressure, the microstructure and optoelectronic properties of GTZO thin films will be changed. When Ar gas pressure is 0.4 Pa, the deposited films possess the best crystal quality and optoelectronic properties.
文摘The residual stress in a 20%SiC w/6061Al composite as extruded was investigated by using X ray stress measurement method. It was found that, high residual stress existed in the composite and residual stress distribution in each direction are not uniform. Relaxation process of residual stress in the composite was dynamically measured during annealing at high temperature. It is verified that the relaxation of residual stress obeys the power law at high temperature. With the creep mechanism, the relaxation behavior of residual stresses at high temperature was analyzed. The results show that, the stress exponent and activation energy for stress relaxation of the composite are obviously higher than those of the matrix alloy.
