This study presents a new method for characterizing the thermal lattice deformation of a monochromator with high precision under service conditions and first reports the operando measurements of nanoscale thermal latt...This study presents a new method for characterizing the thermal lattice deformation of a monochromator with high precision under service conditions and first reports the operando measurements of nanoscale thermal lattice deformation on a double-crystal monochromator at different incident powers.The nanoscale thermal lattice deformation of the monochromator first crystal was obtained by analyzing the intensity of the distorted DuMond diagrams.DuMond diagrams of the 333 diffraction index,sensitive to lattice deformation,were obtained directly using a 2D detector and an analyzer crystal orthogonal to the monochromator.With increasing incident power and power density,the maximum height of the lattice deformation increased from 3.2 to 18.5 nm,and the deformation coefficient of the maximum height increased from 1.1 to 3.2 nm/W.The maximum relative standard deviation was 4.2%,and the maximum standard deviation was 0.1 nm.Based on the measured thermal deformations,the flux saturation phenomenon and critical point for the linear operation of the monochromator were predicted with increasing incident power.This study provides a simple solution to the problem of the lower precision of synchrotron radiation monochromator characterizations compared to simulations.展开更多
This article summarizes the developments of experimental techniques for high pressure x-ray diffraction(XRD) in diamond anvil cells(DACs) using synchrotron radiation. Basic principles and experimental methods for ...This article summarizes the developments of experimental techniques for high pressure x-ray diffraction(XRD) in diamond anvil cells(DACs) using synchrotron radiation. Basic principles and experimental methods for various diffraction geometry are described, including powder diffraction, single crystal diffraction, radial diffraction, as well as coupling with laser heating system. Resolution in d-spacing of different diffraction modes is discussed. More recent progress, such as extended application of single crystal diffraction for measurements of multigrain and electron density distribution, timeresolved diffraction with dynamic DAC and development of modulated heating techniques are briefly introduced. The current status of the high pressure beamline at BSRF(Beijing Synchrotron Radiation Facility) and some results are also presented.展开更多
The ultrahard X-ray multifunctional application beamline(BL12SW)is a phase-II beamline project at the Shanghai Syn-chrotron Radiation Facility.The primary X-ray techniques used at the beamline are high-energy X-ray di...The ultrahard X-ray multifunctional application beamline(BL12SW)is a phase-II beamline project at the Shanghai Syn-chrotron Radiation Facility.The primary X-ray techniques used at the beamline are high-energy X-ray diffraction and imaging using white and monochromatic light.The main scientific objectives of ultrahard X-ray beamlines are focused on two research areas.One is the study of the structural properties of Earth’s interior and new materials under extreme high-temperature and high-pressure conditions,and the other is the characterization of materials and processes in near-real service environments.The beamline utilizes a superconducting wiggler as the light source,with two diamond windows and SiC discs to filter out low-energy light(primarily below 30 keV)and a Cu filter assembly to control the thermal load entering the subsequent optical components.The beamline is equipped with dual monochromators.The first was a meridional bending Laue monochromator cooled by liquid nitrogen,achieving a full-energy coverage of 30-162 keV.The second was a sagittal bending Laue monochromator installed in an external building,providing a focused beam in the horizontal direction with an energy range of 60-120 keV.There were four experimental hutches:two large-volume press experimental hutches(LVP1 and LVP2)and two engineering material experimental hutches(ENG1 and ENG2).Each hutch was equipped with various near-real service conditions to satisfy different requirements.For example,LVP1 and LVP2 were equipped with a 200-ton DDIA press and a 2000-ton dual-mode(DDIA and Kawai)press,respectively.ENG1 and ENG2 provide in situ tensile,creep,and fatigue tests as well as high-temperature conditions.Since June 2023,the BL12SW has been in trial operation.It is expected to officially open to users by early 2024.展开更多
We report here high-pressure investigations on Piplia Kalan eucrite-a member of HED (Howardite -Eucrite-Diogenite) family from asteroid 4-Vesta based on synchrotron X-ray diffraction (up to 16 GPa) and ^57Fe Mossb...We report here high-pressure investigations on Piplia Kalan eucrite-a member of HED (Howardite -Eucrite-Diogenite) family from asteroid 4-Vesta based on synchrotron X-ray diffraction (up to 16 GPa) and ^57Fe Mossbauer spectroscopy (up to 8 GPa). Dominant with anorthite-rich plagioclase, pigeonite-rich pyroxene and clino-ferrosilite, the sample displayed various phase transitions attaining amorphous character at 16 GPa. These phase transitions of individual components could be explained simultaneously through variations in high-pressure XRD patterns and the Mossbauer parameters. Most prominent P21/c to C2/c transition of pigeonite and ferrosilite was exhibited both as sudden variation in Mossbauer parameters and population inversion of Fe^2+ in M1 and M2 sites between 2.9 and 3.8 GPa and variation in intensity profile in XRD patterns at 3.56 GPa. Anorthite seemed to respond more to such impact than other components in the sample. Complete amorphization in anorthite which occurred at lower pressure of - 12 GPa implied residual stress experienced due to shock impact. The presence of high pressure (monoclinic) phase of pigeonite and ferrosilite at ambient condition in this eucrite sample confirmed earlier suggestions of an early shock event. This report is an attempt to emphasize the role of anorthite in the determination of the residual stress due to impact process in the parent body thus to understand the behavioral differences amongst HED members.展开更多
The synchrotron radiation X-ray diffraction technique developed for in situ study ahigh pressure and temperature has also been used to investigate microscopic mineral inclusionsin ultrahigh-pressure metamorphic rocks ...The synchrotron radiation X-ray diffraction technique developed for in situ study ahigh pressure and temperature has also been used to investigate microscopic mineral inclusionsin ultrahigh-pressure metamorphic rocks and deep-mantle samples. Present study added twomore examples of successful utilization of synchrotron radiation X-ray diffraction technique for insitu investigations of fine-grained (0.5―30 μm in size) minerals in very thin shock melt veins othe Suizhou meteorite: ( i ) X-ray diffraction measurement of extremely small-sized vein matrixminerals, and (ii) identification of the micron-sized new mineral tuite embedded in the vein matrixIt has been revealed that the fine-grained vein matrix consists of well crystallized garnet, kamacite and troilite, and the powder diffraction pattern consisting of 17 lines with d-values, intensities( I ), relative intensities (I/Io) and Miller indices, as well as the cell parameters for the new mineratuite has also been successfully obtained. The result of present investigations has enriched thecontent of dynamic high-pressure mineralogy and that of Earth’s mantle geochemistry.展开更多
Because the interactions between molecules and atoms in mediums can be dramatically changed by compression, high pressure studies on materials can provide much information on fundamental properties including phase tra...Because the interactions between molecules and atoms in mediums can be dramatically changed by compression, high pressure studies on materials can provide much information on fundamental properties including phase transition and展开更多
The phase evolution and thermal expansion behavior in superalloy during heating play an essential role in controlling the size and distribution of precipitates,as well as optimizing thermomechanical properties.Synchro...The phase evolution and thermal expansion behavior in superalloy during heating play an essential role in controlling the size and distribution of precipitates,as well as optimizing thermomechanical properties.Synchrotron X-ray diffraction is able to go through the interior of sample and can be carried out with in situ environment,and thus,it can obtain more statistics information in real time comparing with traditional methods,such as electron and optical microscopies.In this study,in situ heating synchrotron X-ray diffraction was carried out to study the phase evolution in a typicalγ′phase precipitation strengthened Ni-based superalloy,Waspaloy,from 29 to 1050°C.Theγ′,γ,M_(23)C_(6)and M C phases,including their lattice parameters,misfits,dissolution behavior and thermal expansion coefficients,were mainly investigated.Theγ′phase and M_(23)C_(6)carbides appeared obvious dissolution during heating and re-precipitated when the temperature dropped to room temperature.Combining with the microscopy results,we can indicate that the dissolution of M_(23)C_(6)leads to the growth of grain andγ′phase cannot be completely dissolved for the short holding time above the solution temperature.Besides,the coefficients of thermal expansions of all the phases are calculated and fitted as polynomials.展开更多
Characterizing the microstructure and deformation mechanism associated with the performances and properties of metallic materials is of great importance in understanding the microstructure-property relationship.The pa...Characterizing the microstructure and deformation mechanism associated with the performances and properties of metallic materials is of great importance in understanding the microstructure-property relationship.The past few decades have witnessed the rapid development of characterization techniques from optical microscopy to electron microscopy,although these conventional methods are generally limited to the sample surface because of the intrinsic opaque nature of metallic materials.Advanced synchrotron radiation(SR)facilities can produce X-rays with strong penetrability and high spatiotemporal resolution,and thereby enabling the non-destructive visualization of full-field structural information in three dimensions.Tremendous endeavors were devoted to the 3 rd generation SR over the past three decades,in which X-ray beams have been focused down to 100 nm.In this paper,recent progresses on SR-related characterization technologies were reviewed,with particular emphases on the fundamentals of synchrotron X-ray imaging and synchrotron X-ray diffraction,as well as their applications in the in situ observations of material preparation(e.g.,in situ dendrite growth during solidification)and service under extreme environment(e.g.,in situ mechanics).Future innovations toward next-generation SR and newly emerging SRbased technologies such as dark-field X-ray microscopy and Bragg coherent X-ray diffraction imaging were also advocated.展开更多
The effect of cryorolling on the precipitation process of deformed Cu-Ni-Si alloys was investigated through in situ synchrotron X-ray diffraction technique. The results demonstrate that the precipitation process is si...The effect of cryorolling on the precipitation process of deformed Cu-Ni-Si alloys was investigated through in situ synchrotron X-ray diffraction technique. The results demonstrate that the precipitation process is significantly accelerated by cryorolling. Cryorolling produces higher dislocation density, which provides more heterogeneous nucleation sites for Ni2Si precipitates, hence promotes precipitation. In the early stage of aging, the enhanced nucleation of precipitates accelerates the depletion of supersaturation, and finer precipitates are obtained. In addition, recrystallization is promoted as a result of high stored energy in the cryorolled Cu-Ni-Si alloys, which facilitates the formation of discontinuous precipitation in the late stage of aging.展开更多
Diffraction enhanced imaging (DEI) with edge enhancement is suitable for the observation of weakly absorbing objects. The potential ability of the DEI was explored for displaying the microanatomy and pathology of hu...Diffraction enhanced imaging (DEI) with edge enhancement is suitable for the observation of weakly absorbing objects. The potential ability of the DEI was explored for displaying the microanatomy and pathology of human eyeball in this work. The images of surgical specimens from malignant intraocular tumor of hospitalized patients were taken using the hard X-rays from the topography station of Beamline 4W1A at Beijing Synchrotron Radiation Facility (BSRF). The obtained radiographic images were analyzed in correlation with those of pathology. The results show that the anatomic and pathologic details of intraocular tumors in human beings can be observed clearly by DEI for the first time, with good visualization of the microscopic details of eyeball ring such as sclera, choroids and other details of intraocular organelles. And the best resolution of DEI images reaches up to the magnitude of several tens of μm. The results suggest that it is capable of exhibiting clearly the details of intraocular tumor using DEI method.展开更多
The impurity-doping in semiconductors is the way to control their electroinc andphoto-electronic properties. The distribution and amount of the dopant affect their physi-cal properties. The development of the molecula...The impurity-doping in semiconductors is the way to control their electroinc andphoto-electronic properties. The distribution and amount of the dopant affect their physi-cal properties. The development of the molecular beam epitaxy (MBE) and other epitaxytechniques has attracted full atttention to new semiconductor materials, such assuperlattices. Recently, δ-doped semiconductors, which can reduce the scattering ofimpurity in two-dimensional electron (hole) systems, have been showing promisingpotentials for scientific researches and techmological applications.展开更多
A one-dimensional single-wire chamber was developed to provide high position resolution for powder diffraction experiments with synchrotron radiation. A diffraction test using the sample of SiO2 has been accomplished ...A one-dimensional single-wire chamber was developed to provide high position resolution for powder diffraction experiments with synchrotron radiation. A diffraction test using the sample of SiO2 has been accomplished at 1W2B laboratory of Beijing Synchrotron Radiation Source. The data of the beam test were analyzed and some diffraction angles were obtained. The experimental results were in good agreement with standard data from ICDD powder diffraction file. The precision of diffraction angles was 1% to 4.7%. Most of the relative errors between measured values of diffraction angles and existing data were less than 1%. As for the detector, the best position resolution in the test was 138 p.m (a value) with an X-ray tube. Finally, discussions of the results were given. The major factor that affected the precision of measurement was deviation from the flat structure of the detector. The effect was analyzed and the conclusion was reached that it would be the optimal measurement scheme when the distance between the powder sample and detector was from 400 mm to 600 mm.展开更多
Development of inhomogeneous deformation is an interest matter in material engineering. Synchrotron radiation tomography provides 3D distribution map of local strain in polycrystalline aluminum alloy by tracking micro...Development of inhomogeneous deformation is an interest matter in material engineering. Synchrotron radiation tomography provides 3D distribution map of local strain in polycrystalline aluminum alloy by tracking microstructural features. To perform further deep analysis on development of inhomogeneous deformation, crystallographic grain orientation is necessary. Three-dimensional X-ray diffraction technique was developed. A new crystallographic orientation measurement method was described in 3D space, utilizing grain boundary tracking (GBT) information.展开更多
Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogen...Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography(XCT) and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional(3-D) rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy(FE-SEM) to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.展开更多
Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will ...Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will seriously affect the X-ray fluorescence analysis. In order to avoid the influence of diffraction, the best way to solve it is to use the monochromatic source, or to have a collimating slit between sample and Si(Li) detector.展开更多
In-situ high-pressure energy dispersive X-ray diffraction experiments of malachite have been performed using diamond anvil cell and synchrotron radiation. The highest recorded pressure is up to 17.4 GPa. The experimen...In-situ high-pressure energy dispersive X-ray diffraction experiments of malachite have been performed using diamond anvil cell and synchrotron radiation. The highest recorded pressure is up to 17.4 GPa. The experimental results reveal that malachite experienced two phase transitions at 0.7 and 7.8 GPa, and the last one is reversible.展开更多
The multilayer Laue lens (MLL) is a novel diffraction optics which can realize nanometer focusing of hard X-rays with high efficiency. In this paper, a 7.9 μm-thick MLL with the outmost layer thickness of 15 nm is ...The multilayer Laue lens (MLL) is a novel diffraction optics which can realize nanometer focusing of hard X-rays with high efficiency. In this paper, a 7.9 μm-thick MLL with the outmost layer thickness of 15 nm is designed based on dynamical diffraction theory. The MLL is fabricated by first depositing the depth-graded multilayer using direct current (DC) magnetron sputtering technology. Then, the multilayer sample is sliced, and both cross-sections are thinned and polished to a depth of 35–41 μm. The focusing property of the MLL is measured at the Shanghai Synchrotron Facility (SSRF). One-dimensional (1D) focusing resolutions of 205 nm and 221 nm are obtained at E=14 keV and 18 keV, respectively. It demonstrates that the fabricated MLL can focus hard X-rays into nanometer scale.展开更多
A setup of blown film machine combined with in situ synchrotron radiation X-ray diffraction measurements and infrared temperature testing is reported to study the structure evolution of polymers during film blowing. T...A setup of blown film machine combined with in situ synchrotron radiation X-ray diffraction measurements and infrared temperature testing is reported to study the structure evolution of polymers during film blowing. Two homemade auto-lifters are constructed and placed under the blown machine at each end of the beamline platform which move up and down with a speed of 0.05 mm/s bearing the 200 kg weight machine. Therefore, structure development and temperature changes as a function of position on the film bubble can be obtained. The blown film machine is customized to be conveniently installed with precise servo motors and can adjust the processing parameters in a wide range. Meanwhile, the air ring has been redesigned in order to track the structure information of the film bubble immediately after the melt being extruded out from the die exit. Polyethylene(PE) is selected as a model system to verify the feasibility of the apparatus and the in situ experimental techniques. Combining structure information provided by the WAXD and SAXS and the actual temperature obtained from the infrared probe, a full roadmap of structure development during film blowing is constructed and it is helpful to explore the molecular mechanism of structure evolution behind the film blowing processing, which is expected to lead to a better understanding of the physics in polymer processing.展开更多
Transition metal selenides have aroused great attention in recent years due to their high theoretical capacity.However,the huge volume fluctuation generated by conversion reaction during the charge/discharge process r...Transition metal selenides have aroused great attention in recent years due to their high theoretical capacity.However,the huge volume fluctuation generated by conversion reaction during the charge/discharge process results in the significant electrochemical performance reduction.Herein,the carbon-regulated copper(I)selenide(Cu_(2)Se@C)is designed to significantly promote the interface stability and ion diffusion for selenide electrodes.The systematic X-ray spectroscopies characterizations and density functional theory(DFT)simulations reveal that the Cu–Se–C bonding forming on the surface of Cu2Se not only improves the electronic conductivity of Cu_(2)Se@C but also retards the volume change during electrochemical cycling,playing a pivotal role in interface regulation.Consequently,the storage kinetics of Cu_(2)Se@C is mainly controlled by the capacitance process diverting from the ion diffusion-controlled process of Cu2Se.When employed this distinctive Cu_(2)Se@C as anode active material in Li coin cell configuration,the ultrahigh specific capacity of 810.3 mA·h·g^(−1)at 0.1 A·g^(−1)and the capacity retention of 83%after 1,500 cycles at 5 A·g^(−1)is achieved,implying the best Cu-based Li^(+)-storage capacity reported so far.This strategy of heterojunction combined with chemical bonding regulation opens up a potential way for the development of advanced electrodes for battery storage systems.展开更多
基金National Natural Science Foundation of China(No.12205360)Shanghai Pilot Program for Basic Research-Chinese Academy of Science,Shanghai Branch(No.JCYJ-SHFY-2021-010).
文摘This study presents a new method for characterizing the thermal lattice deformation of a monochromator with high precision under service conditions and first reports the operando measurements of nanoscale thermal lattice deformation on a double-crystal monochromator at different incident powers.The nanoscale thermal lattice deformation of the monochromator first crystal was obtained by analyzing the intensity of the distorted DuMond diagrams.DuMond diagrams of the 333 diffraction index,sensitive to lattice deformation,were obtained directly using a 2D detector and an analyzer crystal orthogonal to the monochromator.With increasing incident power and power density,the maximum height of the lattice deformation increased from 3.2 to 18.5 nm,and the deformation coefficient of the maximum height increased from 1.1 to 3.2 nm/W.The maximum relative standard deviation was 4.2%,and the maximum standard deviation was 0.1 nm.Based on the measured thermal deformations,the flux saturation phenomenon and critical point for the linear operation of the monochromator were predicted with increasing incident power.This study provides a simple solution to the problem of the lower precision of synchrotron radiation monochromator characterizations compared to simulations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10875142,11079040,and 11075175)The 4W2 beamline of BSRF was supported by the Chinese Academy of Sciences(Grant Nos.KJCX2-SW-N20,KJCX2-SW-N03,and SYGNS04)
文摘This article summarizes the developments of experimental techniques for high pressure x-ray diffraction(XRD) in diamond anvil cells(DACs) using synchrotron radiation. Basic principles and experimental methods for various diffraction geometry are described, including powder diffraction, single crystal diffraction, radial diffraction, as well as coupling with laser heating system. Resolution in d-spacing of different diffraction modes is discussed. More recent progress, such as extended application of single crystal diffraction for measurements of multigrain and electron density distribution, timeresolved diffraction with dynamic DAC and development of modulated heating techniques are briefly introduced. The current status of the high pressure beamline at BSRF(Beijing Synchrotron Radiation Facility) and some results are also presented.
基金National Natural Science Foundation of China(Nos.12334010,42274121).
文摘The ultrahard X-ray multifunctional application beamline(BL12SW)is a phase-II beamline project at the Shanghai Syn-chrotron Radiation Facility.The primary X-ray techniques used at the beamline are high-energy X-ray diffraction and imaging using white and monochromatic light.The main scientific objectives of ultrahard X-ray beamlines are focused on two research areas.One is the study of the structural properties of Earth’s interior and new materials under extreme high-temperature and high-pressure conditions,and the other is the characterization of materials and processes in near-real service environments.The beamline utilizes a superconducting wiggler as the light source,with two diamond windows and SiC discs to filter out low-energy light(primarily below 30 keV)and a Cu filter assembly to control the thermal load entering the subsequent optical components.The beamline is equipped with dual monochromators.The first was a meridional bending Laue monochromator cooled by liquid nitrogen,achieving a full-energy coverage of 30-162 keV.The second was a sagittal bending Laue monochromator installed in an external building,providing a focused beam in the horizontal direction with an energy range of 60-120 keV.There were four experimental hutches:two large-volume press experimental hutches(LVP1 and LVP2)and two engineering material experimental hutches(ENG1 and ENG2).Each hutch was equipped with various near-real service conditions to satisfy different requirements.For example,LVP1 and LVP2 were equipped with a 200-ton DDIA press and a 2000-ton dual-mode(DDIA and Kawai)press,respectively.ENG1 and ENG2 provide in situ tensile,creep,and fatigue tests as well as high-temperature conditions.Since June 2023,the BL12SW has been in trial operation.It is expected to officially open to users by early 2024.
基金Council of Scientific and Industrial Research(CSIR),PLANEX program of India Space Research Organization,Department of Space(Government of India),CSR-SHORE-PSC-02005 and ISRO projects(GP)for funding, CSIR for providing Emeritus Scientist Fellowship(UC)
文摘We report here high-pressure investigations on Piplia Kalan eucrite-a member of HED (Howardite -Eucrite-Diogenite) family from asteroid 4-Vesta based on synchrotron X-ray diffraction (up to 16 GPa) and ^57Fe Mossbauer spectroscopy (up to 8 GPa). Dominant with anorthite-rich plagioclase, pigeonite-rich pyroxene and clino-ferrosilite, the sample displayed various phase transitions attaining amorphous character at 16 GPa. These phase transitions of individual components could be explained simultaneously through variations in high-pressure XRD patterns and the Mossbauer parameters. Most prominent P21/c to C2/c transition of pigeonite and ferrosilite was exhibited both as sudden variation in Mossbauer parameters and population inversion of Fe^2+ in M1 and M2 sites between 2.9 and 3.8 GPa and variation in intensity profile in XRD patterns at 3.56 GPa. Anorthite seemed to respond more to such impact than other components in the sample. Complete amorphization in anorthite which occurred at lower pressure of - 12 GPa implied residual stress experienced due to shock impact. The presence of high pressure (monoclinic) phase of pigeonite and ferrosilite at ambient condition in this eucrite sample confirmed earlier suggestions of an early shock event. This report is an attempt to emphasize the role of anorthite in the determination of the residual stress due to impact process in the parent body thus to understand the behavioral differences amongst HED members.
基金the National Natural Science Foundation of China(Grant No.40272028).
文摘The synchrotron radiation X-ray diffraction technique developed for in situ study ahigh pressure and temperature has also been used to investigate microscopic mineral inclusionsin ultrahigh-pressure metamorphic rocks and deep-mantle samples. Present study added twomore examples of successful utilization of synchrotron radiation X-ray diffraction technique for insitu investigations of fine-grained (0.5―30 μm in size) minerals in very thin shock melt veins othe Suizhou meteorite: ( i ) X-ray diffraction measurement of extremely small-sized vein matrixminerals, and (ii) identification of the micron-sized new mineral tuite embedded in the vein matrixIt has been revealed that the fine-grained vein matrix consists of well crystallized garnet, kamacite and troilite, and the powder diffraction pattern consisting of 17 lines with d-values, intensities( I ), relative intensities (I/Io) and Miller indices, as well as the cell parameters for the new mineratuite has also been successfully obtained. The result of present investigations has enriched thecontent of dynamic high-pressure mineralogy and that of Earth’s mantle geochemistry.
文摘Because the interactions between molecules and atoms in mediums can be dramatically changed by compression, high pressure studies on materials can provide much information on fundamental properties including phase transition and
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.11805009 and 51921001)the Fundamental Research Funds for the Central Universities(Grant No.06111020)。
文摘The phase evolution and thermal expansion behavior in superalloy during heating play an essential role in controlling the size and distribution of precipitates,as well as optimizing thermomechanical properties.Synchrotron X-ray diffraction is able to go through the interior of sample and can be carried out with in situ environment,and thus,it can obtain more statistics information in real time comparing with traditional methods,such as electron and optical microscopies.In this study,in situ heating synchrotron X-ray diffraction was carried out to study the phase evolution in a typicalγ′phase precipitation strengthened Ni-based superalloy,Waspaloy,from 29 to 1050°C.Theγ′,γ,M_(23)C_(6)and M C phases,including their lattice parameters,misfits,dissolution behavior and thermal expansion coefficients,were mainly investigated.Theγ′phase and M_(23)C_(6)carbides appeared obvious dissolution during heating and re-precipitated when the temperature dropped to room temperature.Combining with the microscopy results,we can indicate that the dissolution of M_(23)C_(6)leads to the growth of grain andγ′phase cannot be completely dissolved for the short holding time above the solution temperature.Besides,the coefficients of thermal expansions of all the phases are calculated and fitted as polynomials.
基金financially supported by the National Key Research and Development Plan(Grant Nos.2020YFA0405900,2017YFA0403803)the National Natural Science Foundation of China(Grant No.51927801)the Natural Science Foundation of Jiangsu Province(Grant No.BK20202010)。
文摘Characterizing the microstructure and deformation mechanism associated with the performances and properties of metallic materials is of great importance in understanding the microstructure-property relationship.The past few decades have witnessed the rapid development of characterization techniques from optical microscopy to electron microscopy,although these conventional methods are generally limited to the sample surface because of the intrinsic opaque nature of metallic materials.Advanced synchrotron radiation(SR)facilities can produce X-rays with strong penetrability and high spatiotemporal resolution,and thereby enabling the non-destructive visualization of full-field structural information in three dimensions.Tremendous endeavors were devoted to the 3 rd generation SR over the past three decades,in which X-ray beams have been focused down to 100 nm.In this paper,recent progresses on SR-related characterization technologies were reviewed,with particular emphases on the fundamentals of synchrotron X-ray imaging and synchrotron X-ray diffraction,as well as their applications in the in situ observations of material preparation(e.g.,in situ dendrite growth during solidification)and service under extreme environment(e.g.,in situ mechanics).Future innovations toward next-generation SR and newly emerging SRbased technologies such as dark-field X-ray microscopy and Bragg coherent X-ray diffraction imaging were also advocated.
基金the supports of National Key Research and Development Program of China(No.2017YFA0403803)the National Natural Science Foundation of China(Nos.51525401,51774065,51690163 and 51601028)the Dalian Support Plan for Innovation of High-level Talents(Top and Leading Talents,2015R013)
文摘The effect of cryorolling on the precipitation process of deformed Cu-Ni-Si alloys was investigated through in situ synchrotron X-ray diffraction technique. The results demonstrate that the precipitation process is significantly accelerated by cryorolling. Cryorolling produces higher dislocation density, which provides more heterogeneous nucleation sites for Ni2Si precipitates, hence promotes precipitation. In the early stage of aging, the enhanced nucleation of precipitates accelerates the depletion of supersaturation, and finer precipitates are obtained. In addition, recrystallization is promoted as a result of high stored energy in the cryorolled Cu-Ni-Si alloys, which facilitates the formation of discontinuous precipitation in the late stage of aging.
基金Supported by National Natural Science Foundation (10490195)Key Project of Chinese National Programs for Fundamental Research and Development (973 program) (2006cb500700)Natural Science and Technology Foundation of Guangdong Province(04009356,2008B030301320)
文摘Diffraction enhanced imaging (DEI) with edge enhancement is suitable for the observation of weakly absorbing objects. The potential ability of the DEI was explored for displaying the microanatomy and pathology of human eyeball in this work. The images of surgical specimens from malignant intraocular tumor of hospitalized patients were taken using the hard X-rays from the topography station of Beamline 4W1A at Beijing Synchrotron Radiation Facility (BSRF). The obtained radiographic images were analyzed in correlation with those of pathology. The results show that the anatomic and pathologic details of intraocular tumors in human beings can be observed clearly by DEI for the first time, with good visualization of the microscopic details of eyeball ring such as sclera, choroids and other details of intraocular organelles. And the best resolution of DEI images reaches up to the magnitude of several tens of μm. The results suggest that it is capable of exhibiting clearly the details of intraocular tumor using DEI method.
基金Project spported partially by the major project "Applications of Experimental Synchrotron Radiation Methods" from Chinese Academy of Sciences.
文摘The impurity-doping in semiconductors is the way to control their electroinc andphoto-electronic properties. The distribution and amount of the dopant affect their physi-cal properties. The development of the molecular beam epitaxy (MBE) and other epitaxytechniques has attracted full atttention to new semiconductor materials, such assuperlattices. Recently, δ-doped semiconductors, which can reduce the scattering ofimpurity in two-dimensional electron (hole) systems, have been showing promisingpotentials for scientific researches and techmological applications.
基金National Natural Science Foundation of China (11275224)
文摘A one-dimensional single-wire chamber was developed to provide high position resolution for powder diffraction experiments with synchrotron radiation. A diffraction test using the sample of SiO2 has been accomplished at 1W2B laboratory of Beijing Synchrotron Radiation Source. The data of the beam test were analyzed and some diffraction angles were obtained. The experimental results were in good agreement with standard data from ICDD powder diffraction file. The precision of diffraction angles was 1% to 4.7%. Most of the relative errors between measured values of diffraction angles and existing data were less than 1%. As for the detector, the best position resolution in the test was 138 p.m (a value) with an X-ray tube. Finally, discussions of the results were given. The major factor that affected the precision of measurement was deviation from the flat structure of the detector. The effect was analyzed and the conclusion was reached that it would be the optimal measurement scheme when the distance between the powder sample and detector was from 400 mm to 600 mm.
文摘Development of inhomogeneous deformation is an interest matter in material engineering. Synchrotron radiation tomography provides 3D distribution map of local strain in polycrystalline aluminum alloy by tracking microstructural features. To perform further deep analysis on development of inhomogeneous deformation, crystallographic grain orientation is necessary. Three-dimensional X-ray diffraction technique was developed. A new crystallographic orientation measurement method was described in 3D space, utilizing grain boundary tracking (GBT) information.
基金supported by the Chinese Ministry of Science and Technology(No.2008AA062503)the National Natural Science Foundation Committee of China(Nos.41421064,20637020)the China Postdoctoral Science Foundation(No.20100470166)
文摘Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography(XCT) and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional(3-D) rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy(FE-SEM) to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.
文摘Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will seriously affect the X-ray fluorescence analysis. In order to avoid the influence of diffraction, the best way to solve it is to use the monochromatic source, or to have a collimating slit between sample and Si(Li) detector.
基金supported by the NationalNatural Science Foundation of China(No.40672024)the Knowledge Innovation Project of the Chinese Academyof Sciences(No.KJCX2-SW-N20,KJCX2-SW-N03)
文摘In-situ high-pressure energy dispersive X-ray diffraction experiments of malachite have been performed using diamond anvil cell and synchrotron radiation. The highest recorded pressure is up to 17.4 GPa. The experimental results reveal that malachite experienced two phase transitions at 0.7 and 7.8 GPa, and the last one is reversible.
基金Supported by National Natural Science Foundation of China (10825521)973 Project (2011CB922203)Natural Science Foundation of Shanghai (09ZR1434300)
文摘The multilayer Laue lens (MLL) is a novel diffraction optics which can realize nanometer focusing of hard X-rays with high efficiency. In this paper, a 7.9 μm-thick MLL with the outmost layer thickness of 15 nm is designed based on dynamical diffraction theory. The MLL is fabricated by first depositing the depth-graded multilayer using direct current (DC) magnetron sputtering technology. Then, the multilayer sample is sliced, and both cross-sections are thinned and polished to a depth of 35–41 μm. The focusing property of the MLL is measured at the Shanghai Synchrotron Facility (SSRF). One-dimensional (1D) focusing resolutions of 205 nm and 221 nm are obtained at E=14 keV and 18 keV, respectively. It demonstrates that the fabricated MLL can focus hard X-rays into nanometer scale.
基金financially supported by the National Key R&D Plan of China(2016YFB0302501)
文摘A setup of blown film machine combined with in situ synchrotron radiation X-ray diffraction measurements and infrared temperature testing is reported to study the structure evolution of polymers during film blowing. Two homemade auto-lifters are constructed and placed under the blown machine at each end of the beamline platform which move up and down with a speed of 0.05 mm/s bearing the 200 kg weight machine. Therefore, structure development and temperature changes as a function of position on the film bubble can be obtained. The blown film machine is customized to be conveniently installed with precise servo motors and can adjust the processing parameters in a wide range. Meanwhile, the air ring has been redesigned in order to track the structure information of the film bubble immediately after the melt being extruded out from the die exit. Polyethylene(PE) is selected as a model system to verify the feasibility of the apparatus and the in situ experimental techniques. Combining structure information provided by the WAXD and SAXS and the actual temperature obtained from the infrared probe, a full roadmap of structure development during film blowing is constructed and it is helpful to explore the molecular mechanism of structure evolution behind the film blowing processing, which is expected to lead to a better understanding of the physics in polymer processing.
基金financially supported in part by the National Key Research and Development Program of China(No.2020YFA0405800)the National Natural Science Foundation of China(NSFC,Nos.U1932201 and U2032113)+4 种基金Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS)(No.2022457)CAS Collaborative Innovation Program of Hefei Science Center(No.2020HSC-CIP002)CAS International Partnership Program(No.211134KYSB20190063)the Fundamental Research Funds for the Central Universities(No.WK2060000039)L.S.acknowledges the support from the Institute of Energy,Hefei Comprehensive National Science Center,University Synergy Innovation Program of Anhui Province(No.GXXT-2020-002).
文摘Transition metal selenides have aroused great attention in recent years due to their high theoretical capacity.However,the huge volume fluctuation generated by conversion reaction during the charge/discharge process results in the significant electrochemical performance reduction.Herein,the carbon-regulated copper(I)selenide(Cu_(2)Se@C)is designed to significantly promote the interface stability and ion diffusion for selenide electrodes.The systematic X-ray spectroscopies characterizations and density functional theory(DFT)simulations reveal that the Cu–Se–C bonding forming on the surface of Cu2Se not only improves the electronic conductivity of Cu_(2)Se@C but also retards the volume change during electrochemical cycling,playing a pivotal role in interface regulation.Consequently,the storage kinetics of Cu_(2)Se@C is mainly controlled by the capacitance process diverting from the ion diffusion-controlled process of Cu2Se.When employed this distinctive Cu_(2)Se@C as anode active material in Li coin cell configuration,the ultrahigh specific capacity of 810.3 mA·h·g^(−1)at 0.1 A·g^(−1)and the capacity retention of 83%after 1,500 cycles at 5 A·g^(−1)is achieved,implying the best Cu-based Li^(+)-storage capacity reported so far.This strategy of heterojunction combined with chemical bonding regulation opens up a potential way for the development of advanced electrodes for battery storage systems.