The uncontrollable Li electrostripping and plating process that results in dendritic Li growth and huge volume change of Li anode limits the practicality of Li metal batteries(LMBs).To simultaneously address these iss...The uncontrollable Li electrostripping and plating process that results in dendritic Li growth and huge volume change of Li anode limits the practicality of Li metal batteries(LMBs).To simultaneously address these issues,designing three-dimensional(3D),lithiophilic and mechanically robust electrodes seems to be one of the cost-effective strategies.Herein,a new 3D Li-B-C-Al alloy anode is designed and fabricated.The prepared 3D alloy anode exhibits not only superior lithiophilicity that facilitates uniform Li nucleation and growth but also sufficient mechanical stability that maintains its structural integrity.Superior performance of the prepared 3D alloy is demonstrated through comprehensive electrochemical tests.In addition,non-destructive and 3D synchrotron X-ray computed tomography(SX-CT)technique is employed to investigate the underlying working mechanisms of the prepared alloy anode.A unique twofold Li electrostripping and plating mechanism under different electrochemical cycling conditions is revealed.Lastly,improved performance of the full cells built with the 3D alloy anode and LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathode corroborate its potential application capability.Overall,the current work not only showcases the superiority of the 3D alloy as potential anode material for LMBs but also provides fundamental insights into its underlying working mechanisms that may further propel its research and development.展开更多
Superconductivity is one of most intriguing quantum phenomena,and the quest for elemental superconductors with high critical temperature(T_(c))is of great scientific significance due to their relatively simple materia...Superconductivity is one of most intriguing quantum phenomena,and the quest for elemental superconductors with high critical temperature(T_(c))is of great scientific significance due to their relatively simple material composition and the underlying mechanism.Here we report the experimental discovery of densely compressed scandium(Sc)becoming the first elemental superconductor with T_(c)breaking into 30 K range,which is comparable to the T_(c)values of the classic La-Ba-Cu-O or LaFeAsO superconductors.Our results show that T_(c)^(onset)of Sc increases from~3K at around 43GPa to~32K at about 283GPa(T_(c)^(zero)~31 K),which is well above liquid neon temperature.Interestingly,measured T_(c)shows no sign of saturation up to the maximum pressure achieved in our experiments,indicating that T_(c)may be even higher upon further compression.展开更多
High-performance all-solid-state lithium-ion batteries require observation,control,and optimization of the electrode structure.X-ray computational tomography(CT)is an effective nondestructive method for observing the ...High-performance all-solid-state lithium-ion batteries require observation,control,and optimization of the electrode structure.X-ray computational tomography(CT)is an effective nondestructive method for observing the electrode structure in three dimensions.However,the limited availability of synchrotron radiation CT,which offers high-resolution imaging with a high signal-to-noise ratio,makes it difficult to conduct experiments and restricts the use of X-ray CT in battery development.Conversely,laboratory CT systems are widely available,but they use X-rays emitted from a metal target,resulting in lower image quality and resolution compared with synchrotron radiation CT.This study explores a method for achieving comparable resolution in laboratory CT images of all-solid-state batteries to that of synchrotron radiation CT.Our method involves using the synchrotron radiation CT images as training data for machine learning super-resolution.The results demonstrate that,by employing an appropriate machine learning algorithm and activation function,along with a sufficiently deep network,the image quality of laboratory CT becomes equivalent to that of synchrotron radiation CT.展开更多
Understanding the behavior of matter at extreme pressures of the order of a megabar(Mbar)is essential to gain insight into various physical phenomena at macroscales—the formation of planets,young stars,and the cores ...Understanding the behavior of matter at extreme pressures of the order of a megabar(Mbar)is essential to gain insight into various physical phenomena at macroscales—the formation of planets,young stars,and the cores of super-Earths,and at microscales—damage to ceramic materials and high-pressure plastic transformation and phase transitions in solids.Under dynamic compression of solids up to Mbar pressures,even a solid with high strength exhibits plastic properties,causing the induced shock wave to split in two:an elastic precursor and a plastic shock wave.This phenomenon is described by theoretical models based on indirect measurements of material response.The advent of x-ray free-electron lasers(XFELs)has made it possible to use their ultrashort pulses for direct observations of the propagation of shock waves in solid materials by the method of phase-contrast radiography.However,there is still a lack of comprehensive data for verification of theoretical models of different solids.Here,we present the results of an experiment in which the evolution of the coupled elastic-plastic wave structure in diamond was directly observed and studied with submicrometer spatial resolution,using the unique capabilities of the x-ray free-electron laser(XFEL).The direct measurements allowed,for the first time,the fitting and validation of the 2D failure model for diamond in the range of several Mbar.Our experimental approach opens new possibilities for the direct verification and construction of equations of state of matter in the ultra-high-stress range,which are relevant to solving a variety of problems in high-energy-density physics.展开更多
An overview of the recently renovated high-pressure X-ray diffraction(XRD)BL10XU beamline for the diamond anvil cell at SPring-8 is presented.The renovation includes the replacement of the X-ray source and monochromat...An overview of the recently renovated high-pressure X-ray diffraction(XRD)BL10XU beamline for the diamond anvil cell at SPring-8 is presented.The renovation includes the replacement of the X-ray source and monochromator,enhanced focusing systems for high-energy XRD,and recent progress in the sample environment control techniques that are available for high-pressure studies.Other simultaneous measurement techniques for combination with XRD,such as Raman scattering spectroscopy and Mossbauer spectroscopy,have been developed to obtain complementary information under extreme conditions.These advanced techniques are expected to make significant contributions to in-depth understanding of various and complicated high-pressure phenomena.The experience gained with the BL10XU beamline could help promote high-pressure research in future synchrotron radiation facilities.展开更多
The early Cambrian pentamerous microfossil Olivooides/Punctatus in South China, which is characterized by a diagnostic stellate tubular apex, has been well-known for its almost complete development sequence that can b...The early Cambrian pentamerous microfossil Olivooides/Punctatus in South China, which is characterized by a diagnostic stellate tubular apex, has been well-known for its almost complete development sequence that can be confidently traced from embryos and hatched juveniles, to conical adults. However, its zoological affinity remains highly controversial. Here we describe the internal microanatomic structures of the soft-body inside the peridermal theca of Olivooides multisulcatus Qian, 1977, including interradial pairs of tentacles, adradial and perradial frenula, perradial oral marginal lappets and twins of perradial gastric saccule-like humps as well as a circular velarium with striated coronal muscles. Particularly, one specimen shows bifurcated velarial canals along the bell aperture. Both the components of the soft-body and the external theca (or cyst) are arranged in perfect pentaradial symmetry. These characteristics are more compatible with those of living cubomedusans and co-occurring Cambrian athecate embryonic cubozoans. Concerning the presence of peridermal theca, Olivooides most likely represents an extinct thecate stem-group cubomedusae but devoid of both perradial eyes and specialized pedalia. The well-grown soft body inside the peridermal tube displays a set of mixed features of both polyp and medusa.展开更多
Magnetic properties were investigated for the rare-earth 3d-transition metal oxides with the perovskite structure. Intriguing magnetic phenomena were reviewed for a few systems:magnetization peak effect in the titanat...Magnetic properties were investigated for the rare-earth 3d-transition metal oxides with the perovskite structure. Intriguing magnetic phenomena were reviewed for a few systems:magnetization peak effect in the titanates, magnetization reversal in the chromites and metallic ferromagnetism in the cobaltites. The results suggest an important role of the rare-earth ions for the magnetic properties of such complex oxides.展开更多
Synchrotron radiation x-ray diffraction investigations of iron(Fe)and nickel(Ni)are conducted at pressures up to 354 and 368 GPa,respectively,and the equations of state(EOSs)at 298 K for the two elements are obtained ...Synchrotron radiation x-ray diffraction investigations of iron(Fe)and nickel(Ni)are conducted at pressures up to 354 and 368 GPa,respectively,and the equations of state(EOSs)at 298 K for the two elements are obtained for data extending to pressures as high as those at the center of the Earth,using the latest Pt-EOS pressure scale.From a least-squares fit to the Vinet equation using the observed pressure–volume data,the isothermal bulk modulus K0 and its pressure derivative K′0 are estimated to be 159.27(99)GPa and 5.86(4)for hcp-Fe,and 173.5(1.4)GPa and 5.55(5)for Ni.By comparing the present EOSs and extrapolated EOSs reported in the literature for Fe and Ni,the volumes of Fe and Ni at 365 GPa are found to be 2.3%and 1.5%larger than those estimated from extrapolated EOSs in previous studies,respectively.It is concluded that these discrepancies are due to the pressure scale.The present results suggest that the densities of Fe and Ni at a pressure of 365 GPa corresponding to the center of the Earth are 2.3%and 1.5%,respectively,lower than previously thought.展开更多
Multilayer polarization elements and their applications to polarimetric studies in 20~400 eV region are mainly reviewed. General principle of selecting material combinations to get high linear polarizance multilayers...Multilayer polarization elements and their applications to polarimetric studies in 20~400 eV region are mainly reviewed. General principle of selecting material combinations to get high linear polarizance multilayers of reflection type is given with practical examples,with periodic or non-periodic layer structures depending on the usage. Transmission type is introduced as linear polarizer and phase shifter. Their applications include polarization diagnosis of laboratory optical systems and synchrotron radiation beamlines of linear and circular polarization,magnetic rotation experiments such as Faraday rotation and magnetic Kerr rotation on magnetic films and multilayers,and ellipsometry to measure optical constants of thin films precisely. Polarization analysis of soft X-ray fluorescence using multilayer-coated grating is also mentioned. Finally this review is summarized with outlook of further developments.展开更多
We present new diagnostics for use in optical laser pump-X-ray Free Electron Laser(XFEL)probe experiments to monitor dimensions,intensity profile and focusability of the XFEL beam and to control initial quality and ho...We present new diagnostics for use in optical laser pump-X-ray Free Electron Laser(XFEL)probe experiments to monitor dimensions,intensity profile and focusability of the XFEL beam and to control initial quality and homogeneity of targets to be driven by optical laser pulse.By developing X-ray imaging,based on the use of an LiF crystal detector,we were able to measure the distribution of energy inside a hard X-ray beam with unprecedented high spatial resolution(~1 mm)and across a field of view larger than some millimetres.This diagnostic can be used in situ,provides a very high dynamic range,has an extremely limited cost,and is relatively easy to be implemented in pump-probe experiments.The proposed methods were successfully applied in pump-probe experiments at the SPring-8 Angstrom Compact free electron LAser(SACLA)XFEL facility and its potential was demonstrated for current and future High Energy Density Science experiments.展开更多
The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer,which are usually determined by the structure of catalyst supports,is crucial for the oxygen reduction ...The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer,which are usually determined by the structure of catalyst supports,is crucial for the oxygen reduction reaction(ORR).In this study,an oleic acid-assisted soft-templating approach is developed to synthesize size-controlled nitrogen-doped carbon nanoparticles(ranging from 130 nm to 60 nm and 35 nm,respectively)that feature spiral mesopores on their surface(SMCs).Next,atomically dispersed Fe–Nx sites are fabricated on the size-tunable SMCs(Fe1/SMC-x,where x represents the SMC size)and the size-dependent activity toward ORR is investigated.It is found that the catalytic performance of Fe1/SMCs is significantly influenced by the size of SMCs,where the Fe1/SMC-60 catalyst shows the highest ORR activity with a half-wave potential of 0.90 V vs.RHE in KOH electrolyte,indicating that the gas-liquid-solid three-phase interface on the Fe1/SMC-60 enhances the accessibility of Fe–Nx sites.In addition,when using Fe1/SMC-60 as the cathode catalyst in aqueous zinc-air batteries(ZABs),it delivers a higher open-circuit voltage(1.514 V),a greater power density(223 mW cm−2),and a larger specific capacity/energy than Pt/C-based counterparts.These results further highlight the potential of Fe1/SMC60 for practical energy devices associated with ORR and the importance of size-controlled synthesis of SMCs.展开更多
With exceptional capacity during high-voltage cycling,P3-type Nadeficient layered oxide cathodes have captured substantial attention.Nevertheless,they are plagued by severe capacity degradation over cycling.In this st...With exceptional capacity during high-voltage cycling,P3-type Nadeficient layered oxide cathodes have captured substantial attention.Nevertheless,they are plagued by severe capacity degradation over cycling.In this study,tuning and optimizing the phase composition in layered oxides through Li incorporation are proposed to enhance the high-voltage stability.The structural dependence of layered Na_(2/3)LixNi_(0.25)Mn_(0.75)O_(2)þδoxides on the lithium content(0.0≤x≤1.0)offered during synthesis is investigated systematically on an atomic scale.Surprisingly,increasing the Li content triggers the formation of mixed P2/O3-type or P3/P2/O3-type layered phases.As the voltage window is 1.5-4.5 V,P3-type Na2/3Ni_(0.25)Mn_(0.75)O_(2)(NL0.0NMO,R3m)material exhibits a sequence of phase transformations throughout the process of(de)sodiation,that is,O3⇌P3⇌O30⇌O3″.Such complicated phase transitions can be effectively suppressed in the Na2/3Li_(0.7)Ni_(0.25)Mn_(0.75)O_(2.4)(NL_(0.7)NMO)oxide with P2/P3/O3-type mixed phases.Consequently,cathodes made of NL0.7NMO exhibit a substantially enhanced cyclic performance at high voltages compared to that of the P3-type layered NL0.0NMO cathode.Specifically,NL0.7NMO demonstrates an outstanding capacity retention of 98%after 10 cycles at 1 C within 1.5-4.5 V,much higher than that of NL0.0NMO(83%).This work delves into the intricate realm of bolstering the high-voltage durability of layered oxide cathodes,paving the way for advanced sodium-ion battery technologies.展开更多
A fully coherent free electron laser(FEL) seeded with a higher-order harmonic(HH) pulse from high-order harmonic generation(HHG) is successfully operated for a sufficiently prolonged time in pilot user experiments by ...A fully coherent free electron laser(FEL) seeded with a higher-order harmonic(HH) pulse from high-order harmonic generation(HHG) is successfully operated for a sufficiently prolonged time in pilot user experiments by using a timing drift feedback. For HHG-seeded FELs, the seeding laser pulses have to be synchronized with electron bunches. Despite seeded FELs being non-chaotic light sources in principle, external laser-seeded FELs are often unstable in practice because of a timing jitter and a drift between the seeding laser pulses and the accelerated electron bunches. Accordingly,we constructed a relative arrival-timing monitor based on non-invasive electro-optic sampling(EOS). The EOS monitor made uninterrupted shot-to-shot monitoring possible even during the seeded FEL operation. The EOS system was then used for arrival-timing feedback with an adjustability of 100 fs for continual operation of the HHG-seeded FEL. Using the EOS-based beam drift controlling system, the HHG-seeded FEL was operated over half a day with an effective hit rate of 20%–30%. The output pulse energy was 20 μJ at the 61.2 nm wavelength. Towards seeded FELs in the water window region, we investigated our upgrade plan to seed high-power FELs with HH photon energy of 30–100 e V and lase at shorter wavelengths of up to 2 nm through high-gain harmonic generation(HGHG) at the energy-upgraded SPring-8Compact SASE Source(SCSS) accelerator. We studied a benefit as well as the feasibility of the next HHG-seeded FEL machine with single-stage HGHG with tunability of a lasing wavelength.展开更多
Crystalline ErCl_(3) nanowires have been fabricated in single-walled carbon nanotubes(SWCNTs)with high yield(~90%),and the structural and magnetic properties of the resulting ErCl_(3) nanowires encapsulated in SWCNTs(...Crystalline ErCl_(3) nanowires have been fabricated in single-walled carbon nanotubes(SWCNTs)with high yield(~90%),and the structural and magnetic properties of the resulting ErCl_(3) nanowires encapsulated in SWCNTs(ErCl_(3)@SWCNTs)characterized.Encapsulation under high temperature and vacuum using high quality SWCNTs results in a high fi lling-ratio of ErCl_(3) nanowires in the SWCNTs.The high fi lling-ratio of ErCl_(3) nanowires and the use of highly pure SWCNTs with only a small amount of residual Fe catalyst nanoparticles enabled us to observe the magnetic properties of ErCl_(3)@SWCNTs.Structure determination based on simulated annealing calculations and high-resolution transmission electron microscope(HRTEM)image simulations revealed that the structure of the ErCl_(3) nanowires is unusual with respect to the coordination environment of the Eu3+ions.This work opens up new possibilities to fabricate various metal complex nanowires with high yield and may also be of more general importance in understanding and exploring magnetic properties in low-dimensional magnetic systems.展开更多
Recently we have constructed two facilities for generating photon beams in the MeV and sub-MeV energy regions by means of the Compton backscattering with a laser and an electron beam at SPring-8 and at Kansai Photon S...Recently we have constructed two facilities for generating photon beams in the MeV and sub-MeV energy regions by means of the Compton backscattering with a laser and an electron beam at SPring-8 and at Kansai Photon Science Institute of Japan Atomic Energy Agency(KPSI-JAEA). The MeV-photon source at SPring-8 consists of a continuous-wave optically-pumped far infrared laser with a wavelength of 118.8 μm and an 8 GeV stored electron beam. Present MeV-photon flux is estimated to be 1.3×103 photons/s. On the other hand,the sub-MeV-photon source at KPSI-JAEA consists of a pulse Nd∶YAG laser with a wavelength of 1 064 nm and a 150 MeV electron beam accelerated by microtron. In the first trial of the photon production in this source,backscattered photon flux is estimated to be 20 photons/pulse. Both the Compton backscattered photon sources have possibilities to be used for new tools in various fields such as nuclear physics,materials science,and astronomy.展开更多
This paper provides a review on sample injectors which are provided at SPring-8 Angstrom Compact free electron LAser(SACLA) for conducting serial measurement in a ‘diffract-before-destroy' scheme using an x-ray f...This paper provides a review on sample injectors which are provided at SPring-8 Angstrom Compact free electron LAser(SACLA) for conducting serial measurement in a ‘diffract-before-destroy' scheme using an x-ray free electron laser(XFEL). Versatile experimental platforms at SACLA are able to accept various types of injectors, among which liquidjet, droplet and viscous carrier injectors are frequently utilized. These injectors produce different forms of fluid targets such as a liquid filament with a diameter in the order of micrometer, micro-droplet synchronized to XFEL pulses, and slowly flowing column of highly viscous fluid with a rate below 1 μL min-1. Characteristics and applications of the injectors are described.展开更多
基金supported by the National Natural Science Foundation of China(U1904216).
文摘The uncontrollable Li electrostripping and plating process that results in dendritic Li growth and huge volume change of Li anode limits the practicality of Li metal batteries(LMBs).To simultaneously address these issues,designing three-dimensional(3D),lithiophilic and mechanically robust electrodes seems to be one of the cost-effective strategies.Herein,a new 3D Li-B-C-Al alloy anode is designed and fabricated.The prepared 3D alloy anode exhibits not only superior lithiophilicity that facilitates uniform Li nucleation and growth but also sufficient mechanical stability that maintains its structural integrity.Superior performance of the prepared 3D alloy is demonstrated through comprehensive electrochemical tests.In addition,non-destructive and 3D synchrotron X-ray computed tomography(SX-CT)technique is employed to investigate the underlying working mechanisms of the prepared alloy anode.A unique twofold Li electrostripping and plating mechanism under different electrochemical cycling conditions is revealed.Lastly,improved performance of the full cells built with the 3D alloy anode and LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathode corroborate its potential application capability.Overall,the current work not only showcases the superiority of the 3D alloy as potential anode material for LMBs but also provides fundamental insights into its underlying working mechanisms that may further propel its research and development.
基金supported by the National Key R&D Program of China(Grant No.2021YFA1401800,2022YFA1403800,and 2022YFA1403900)the National Natural Science Foundation of China(Grant Nos.11921004 and U2032220)+1 种基金Chinese Academy of Sciences(Grant No.XDB33010200)NSERC Canada for a Discovery Grant。
文摘Superconductivity is one of most intriguing quantum phenomena,and the quest for elemental superconductors with high critical temperature(T_(c))is of great scientific significance due to their relatively simple material composition and the underlying mechanism.Here we report the experimental discovery of densely compressed scandium(Sc)becoming the first elemental superconductor with T_(c)breaking into 30 K range,which is comparable to the T_(c)values of the classic La-Ba-Cu-O or LaFeAsO superconductors.Our results show that T_(c)^(onset)of Sc increases from~3K at around 43GPa to~32K at about 283GPa(T_(c)^(zero)~31 K),which is well above liquid neon temperature.Interestingly,measured T_(c)shows no sign of saturation up to the maximum pressure achieved in our experiments,indicating that T_(c)may be even higher upon further compression.
基金The synchrotron radiation measurements were performed at BL20XU at SPring-8,with the approval of the Japan Syn-chrotron Radiation Research Institute(JASRI,proposal numbers 2022B1020,2022A1003,2021B1005,2021B1004,2021A1017,2020A1782).
文摘High-performance all-solid-state lithium-ion batteries require observation,control,and optimization of the electrode structure.X-ray computational tomography(CT)is an effective nondestructive method for observing the electrode structure in three dimensions.However,the limited availability of synchrotron radiation CT,which offers high-resolution imaging with a high signal-to-noise ratio,makes it difficult to conduct experiments and restricts the use of X-ray CT in battery development.Conversely,laboratory CT systems are widely available,but they use X-rays emitted from a metal target,resulting in lower image quality and resolution compared with synchrotron radiation CT.This study explores a method for achieving comparable resolution in laboratory CT images of all-solid-state batteries to that of synchrotron radiation CT.Our method involves using the synchrotron radiation CT images as training data for machine learning super-resolution.The results demonstrate that,by employing an appropriate machine learning algorithm and activation function,along with a sufficiently deep network,the image quality of laboratory CT becomes equivalent to that of synchrotron radiation CT.
基金We thank the technical staff of SACLA for their support during the experiment.The experiment was performed at BL3 of SACLA with the approval of the Japan Synchrotron Radiation Research Institute(Proposal Nos.2021A8004 and 2021B8002).The high-power drive laser installed in SACLA EH5 was developed with the cooperation of Hamamatsu Photonics.The installation of diffractive optical elements to improve the smoothness of the drive laser-pattern was supported by the SACLA Basic Development ProgramThe work was carried out with the financial support of the Russian Federation represented by the Ministry of Science and Higher Education of the Russian Federation(Grant No.075-15-2021-1352)This work was supported by KAKENHI(Grant Nos.17K05729 and 21K03499)from the Japan Society for the Promotion of Science(JSPS).
文摘Understanding the behavior of matter at extreme pressures of the order of a megabar(Mbar)is essential to gain insight into various physical phenomena at macroscales—the formation of planets,young stars,and the cores of super-Earths,and at microscales—damage to ceramic materials and high-pressure plastic transformation and phase transitions in solids.Under dynamic compression of solids up to Mbar pressures,even a solid with high strength exhibits plastic properties,causing the induced shock wave to split in two:an elastic precursor and a plastic shock wave.This phenomenon is described by theoretical models based on indirect measurements of material response.The advent of x-ray free-electron lasers(XFELs)has made it possible to use their ultrashort pulses for direct observations of the propagation of shock waves in solid materials by the method of phase-contrast radiography.However,there is still a lack of comprehensive data for verification of theoretical models of different solids.Here,we present the results of an experiment in which the evolution of the coupled elastic-plastic wave structure in diamond was directly observed and studied with submicrometer spatial resolution,using the unique capabilities of the x-ray free-electron laser(XFEL).The direct measurements allowed,for the first time,the fitting and validation of the 2D failure model for diamond in the range of several Mbar.Our experimental approach opens new possibilities for the direct verification and construction of equations of state of matter in the ultra-high-stress range,which are relevant to solving a variety of problems in high-energy-density physics.
基金This work was partially supported by RIKEN,Japan,and MEXT/JSPS KAKENHI GrantsNos.JP24000005 and JP16H06285(to K.H.),JP26000006(to K.S.),and JP22000002 and JP15H05748(to E.O.).This work was performed under SPring-8 proposals.43 Comments from anonymous reviewers were helpful in improving the manuscript.
文摘An overview of the recently renovated high-pressure X-ray diffraction(XRD)BL10XU beamline for the diamond anvil cell at SPring-8 is presented.The renovation includes the replacement of the X-ray source and monochromator,enhanced focusing systems for high-energy XRD,and recent progress in the sample environment control techniques that are available for high-pressure studies.Other simultaneous measurement techniques for combination with XRD,such as Raman scattering spectroscopy and Mossbauer spectroscopy,have been developed to obtain complementary information under extreme conditions.These advanced techniques are expected to make significant contributions to in-depth understanding of various and complicated high-pressure phenomena.The experience gained with the BL10XU beamline could help promote high-pressure research in future synchrotron radiation facilities.
基金supported by the Natural Science Foundation of China(NSFC grant 41272019,41372021)the "973 project" of the Ministry of Science and Technology of China"(2013CB835002, 2013CB837100)+1 种基金the "111 project" of the Programs of Introducing Talents of Discipline to Universities(No: W20136100061)the MOST Special Fund from the State Key Laboratory of Continental Dynamics,Northwest University,China
文摘The early Cambrian pentamerous microfossil Olivooides/Punctatus in South China, which is characterized by a diagnostic stellate tubular apex, has been well-known for its almost complete development sequence that can be confidently traced from embryos and hatched juveniles, to conical adults. However, its zoological affinity remains highly controversial. Here we describe the internal microanatomic structures of the soft-body inside the peridermal theca of Olivooides multisulcatus Qian, 1977, including interradial pairs of tentacles, adradial and perradial frenula, perradial oral marginal lappets and twins of perradial gastric saccule-like humps as well as a circular velarium with striated coronal muscles. Particularly, one specimen shows bifurcated velarial canals along the bell aperture. Both the components of the soft-body and the external theca (or cyst) are arranged in perfect pentaradial symmetry. These characteristics are more compatible with those of living cubomedusans and co-occurring Cambrian athecate embryonic cubozoans. Concerning the presence of peridermal theca, Olivooides most likely represents an extinct thecate stem-group cubomedusae but devoid of both perradial eyes and specialized pedalia. The well-grown soft body inside the peridermal tube displays a set of mixed features of both polyp and medusa.
文摘Magnetic properties were investigated for the rare-earth 3d-transition metal oxides with the perovskite structure. Intriguing magnetic phenomena were reviewed for a few systems:magnetization peak effect in the titanates, magnetization reversal in the chromites and metallic ferromagnetism in the cobaltites. The results suggest an important role of the rare-earth ions for the magnetic properties of such complex oxides.
基金JSPS KAKENHI Grant Nos.JP17·6708,JP19740332,and JP19K04051 to N.H.and Grant No.JP17K05550 to Y.A.the SPring-8 facility with the approval of the JASRI(Proposal Nos.2005B0272,2005B0307,2006A1077,2006A1307,2006A1792,2007A1277,2007A1286,2008B1247,2009A1444,2018B1144,and 2020A1194).
文摘Synchrotron radiation x-ray diffraction investigations of iron(Fe)and nickel(Ni)are conducted at pressures up to 354 and 368 GPa,respectively,and the equations of state(EOSs)at 298 K for the two elements are obtained for data extending to pressures as high as those at the center of the Earth,using the latest Pt-EOS pressure scale.From a least-squares fit to the Vinet equation using the observed pressure–volume data,the isothermal bulk modulus K0 and its pressure derivative K′0 are estimated to be 159.27(99)GPa and 5.86(4)for hcp-Fe,and 173.5(1.4)GPa and 5.55(5)for Ni.By comparing the present EOSs and extrapolated EOSs reported in the literature for Fe and Ni,the volumes of Fe and Ni at 365 GPa are found to be 2.3%and 1.5%larger than those estimated from extrapolated EOSs in previous studies,respectively.It is concluded that these discrepancies are due to the pressure scale.The present results suggest that the densities of Fe and Ni at a pressure of 365 GPa corresponding to the center of the Earth are 2.3%and 1.5%,respectively,lower than previously thought.
文摘Multilayer polarization elements and their applications to polarimetric studies in 20~400 eV region are mainly reviewed. General principle of selecting material combinations to get high linear polarizance multilayers of reflection type is given with practical examples,with periodic or non-periodic layer structures depending on the usage. Transmission type is introduced as linear polarizer and phase shifter. Their applications include polarization diagnosis of laboratory optical systems and synchrotron radiation beamlines of linear and circular polarization,magnetic rotation experiments such as Faraday rotation and magnetic Kerr rotation on magnetic films and multilayers,and ellipsometry to measure optical constants of thin films precisely. Polarization analysis of soft X-ray fluorescence using multilayer-coated grating is also mentioned. Finally this review is summarized with outlook of further developments.
基金The XFEL experiments were performed at the BL3 of SACLA with the approval of the Japan Synchrotron Radiation Research Institute(JASRI)(Proposals Nos.2014A8045,and 2014B8068)This research was partially supported by grants from Grants-in-Aid for Scientific Research(Kakenhi Grant Nos.15H02153 and 17K05729)+1 种基金the Core-to-Core Program on International Alliance for Material Science in Extreme States with High Power Laser of the Japan Society for the Promotion of Science(JSPS),from the X-ray Free Electron Laser Priority Strategy Program of the MEXT,contract 12005014,and within the state assignment of FASO of Russia(theme N01201357846)The part of work was supported by the Agence Nationale de la Recherche in the frame of the ANR project TurboHEDP(ANR-15-CE30-0011).
文摘We present new diagnostics for use in optical laser pump-X-ray Free Electron Laser(XFEL)probe experiments to monitor dimensions,intensity profile and focusability of the XFEL beam and to control initial quality and homogeneity of targets to be driven by optical laser pulse.By developing X-ray imaging,based on the use of an LiF crystal detector,we were able to measure the distribution of energy inside a hard X-ray beam with unprecedented high spatial resolution(~1 mm)and across a field of view larger than some millimetres.This diagnostic can be used in situ,provides a very high dynamic range,has an extremely limited cost,and is relatively easy to be implemented in pump-probe experiments.The proposed methods were successfully applied in pump-probe experiments at the SPring-8 Angstrom Compact free electron LAser(SACLA)XFEL facility and its potential was demonstrated for current and future High Energy Density Science experiments.
基金supported by Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant(ZR2022ZD30)Qingdao New Energy Shandong Laboratory Open Project(Grant:QNESL OP 202307)+2 种基金Natural Science Foundation of Shandong Province(ZR2023QB103)China Postdoctoral Science Foundation(2023M733609)Qingdao Postdoctoral Applied Research Project(QDBSH20230202075).
文摘The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer,which are usually determined by the structure of catalyst supports,is crucial for the oxygen reduction reaction(ORR).In this study,an oleic acid-assisted soft-templating approach is developed to synthesize size-controlled nitrogen-doped carbon nanoparticles(ranging from 130 nm to 60 nm and 35 nm,respectively)that feature spiral mesopores on their surface(SMCs).Next,atomically dispersed Fe–Nx sites are fabricated on the size-tunable SMCs(Fe1/SMC-x,where x represents the SMC size)and the size-dependent activity toward ORR is investigated.It is found that the catalytic performance of Fe1/SMCs is significantly influenced by the size of SMCs,where the Fe1/SMC-60 catalyst shows the highest ORR activity with a half-wave potential of 0.90 V vs.RHE in KOH electrolyte,indicating that the gas-liquid-solid three-phase interface on the Fe1/SMC-60 enhances the accessibility of Fe–Nx sites.In addition,when using Fe1/SMC-60 as the cathode catalyst in aqueous zinc-air batteries(ZABs),it delivers a higher open-circuit voltage(1.514 V),a greater power density(223 mW cm−2),and a larger specific capacity/energy than Pt/C-based counterparts.These results further highlight the potential of Fe1/SMC60 for practical energy devices associated with ORR and the importance of size-controlled synthesis of SMCs.
基金Distinguished Young Foundation of Sichuan Province,Grant/Award Number:2020JDJQ0027National Natural Science Foundation of China,Grant/Award Numbers:22108218,20A20145,21878195+2 种基金German Research Foundation,Grant/Award Number:390874152“Young Talent Support Plan”of Xi'an Jiaotong University,Grant/Award Number:HG6J016Qinchuangyuan Innovative Talent Project,Grant/Award Number:QCYRCXM-2022-137。
文摘With exceptional capacity during high-voltage cycling,P3-type Nadeficient layered oxide cathodes have captured substantial attention.Nevertheless,they are plagued by severe capacity degradation over cycling.In this study,tuning and optimizing the phase composition in layered oxides through Li incorporation are proposed to enhance the high-voltage stability.The structural dependence of layered Na_(2/3)LixNi_(0.25)Mn_(0.75)O_(2)þδoxides on the lithium content(0.0≤x≤1.0)offered during synthesis is investigated systematically on an atomic scale.Surprisingly,increasing the Li content triggers the formation of mixed P2/O3-type or P3/P2/O3-type layered phases.As the voltage window is 1.5-4.5 V,P3-type Na2/3Ni_(0.25)Mn_(0.75)O_(2)(NL0.0NMO,R3m)material exhibits a sequence of phase transformations throughout the process of(de)sodiation,that is,O3⇌P3⇌O30⇌O3″.Such complicated phase transitions can be effectively suppressed in the Na2/3Li_(0.7)Ni_(0.25)Mn_(0.75)O_(2.4)(NL_(0.7)NMO)oxide with P2/P3/O3-type mixed phases.Consequently,cathodes made of NL0.7NMO exhibit a substantially enhanced cyclic performance at high voltages compared to that of the P3-type layered NL0.0NMO cathode.Specifically,NL0.7NMO demonstrates an outstanding capacity retention of 98%after 10 cycles at 1 C within 1.5-4.5 V,much higher than that of NL0.0NMO(83%).This work delves into the intricate realm of bolstering the high-voltage durability of layered oxide cathodes,paving the way for advanced sodium-ion battery technologies.
基金supported by the Ministry of Business, Innovation and Employment Catalyst Fund (MAUX 1609)the University of Auckland Faculty Research Development Fund+1 种基金the MacDiarmid Institute for Advanced Materials and Nanotechnologya generous philanthropic donation from Greg and Kathryn Trounson。
文摘A fully coherent free electron laser(FEL) seeded with a higher-order harmonic(HH) pulse from high-order harmonic generation(HHG) is successfully operated for a sufficiently prolonged time in pilot user experiments by using a timing drift feedback. For HHG-seeded FELs, the seeding laser pulses have to be synchronized with electron bunches. Despite seeded FELs being non-chaotic light sources in principle, external laser-seeded FELs are often unstable in practice because of a timing jitter and a drift between the seeding laser pulses and the accelerated electron bunches. Accordingly,we constructed a relative arrival-timing monitor based on non-invasive electro-optic sampling(EOS). The EOS monitor made uninterrupted shot-to-shot monitoring possible even during the seeded FEL operation. The EOS system was then used for arrival-timing feedback with an adjustability of 100 fs for continual operation of the HHG-seeded FEL. Using the EOS-based beam drift controlling system, the HHG-seeded FEL was operated over half a day with an effective hit rate of 20%–30%. The output pulse energy was 20 μJ at the 61.2 nm wavelength. Towards seeded FELs in the water window region, we investigated our upgrade plan to seed high-power FELs with HH photon energy of 30–100 e V and lase at shorter wavelengths of up to 2 nm through high-gain harmonic generation(HGHG) at the energy-upgraded SPring-8Compact SASE Source(SCSS) accelerator. We studied a benefit as well as the feasibility of the next HHG-seeded FEL machine with single-stage HGHG with tunability of a lasing wavelength.
基金by the JST CREST Program for novel carbon nanotube materialsThe XAS experiments were performed at BL25SU in SPring-8 with the approval of JASRT(Proposal No.2007B1732).
文摘Crystalline ErCl_(3) nanowires have been fabricated in single-walled carbon nanotubes(SWCNTs)with high yield(~90%),and the structural and magnetic properties of the resulting ErCl_(3) nanowires encapsulated in SWCNTs(ErCl_(3)@SWCNTs)characterized.Encapsulation under high temperature and vacuum using high quality SWCNTs results in a high fi lling-ratio of ErCl_(3) nanowires in the SWCNTs.The high fi lling-ratio of ErCl_(3) nanowires and the use of highly pure SWCNTs with only a small amount of residual Fe catalyst nanoparticles enabled us to observe the magnetic properties of ErCl_(3)@SWCNTs.Structure determination based on simulated annealing calculations and high-resolution transmission electron microscope(HRTEM)image simulations revealed that the structure of the ErCl_(3) nanowires is unusual with respect to the coordination environment of the Eu3+ions.This work opens up new possibilities to fabricate various metal complex nanowires with high yield and may also be of more general importance in understanding and exploring magnetic properties in low-dimensional magnetic systems.
基金Japan Societyfor Promotion of Science under Grant-and Aid for Scientific Research(14205018)Ministry of Educa-tion,Science,Sports and Culture of Japan under Grant-and-Aid for Specially Promoted Research (15002013)
文摘Recently we have constructed two facilities for generating photon beams in the MeV and sub-MeV energy regions by means of the Compton backscattering with a laser and an electron beam at SPring-8 and at Kansai Photon Science Institute of Japan Atomic Energy Agency(KPSI-JAEA). The MeV-photon source at SPring-8 consists of a continuous-wave optically-pumped far infrared laser with a wavelength of 118.8 μm and an 8 GeV stored electron beam. Present MeV-photon flux is estimated to be 1.3×103 photons/s. On the other hand,the sub-MeV-photon source at KPSI-JAEA consists of a pulse Nd∶YAG laser with a wavelength of 1 064 nm and a 150 MeV electron beam accelerated by microtron. In the first trial of the photon production in this source,backscattered photon flux is estimated to be 20 photons/pulse. Both the Compton backscattered photon sources have possibilities to be used for new tools in various fields such as nuclear physics,materials science,and astronomy.
基金supported by the X-ray FreeElectron Laser Priority Strategy Program (MEXT)JSPS KAKENHI Grant Number 15K05407
文摘This paper provides a review on sample injectors which are provided at SPring-8 Angstrom Compact free electron LAser(SACLA) for conducting serial measurement in a ‘diffract-before-destroy' scheme using an x-ray free electron laser(XFEL). Versatile experimental platforms at SACLA are able to accept various types of injectors, among which liquidjet, droplet and viscous carrier injectors are frequently utilized. These injectors produce different forms of fluid targets such as a liquid filament with a diameter in the order of micrometer, micro-droplet synchronized to XFEL pulses, and slowly flowing column of highly viscous fluid with a rate below 1 μL min-1. Characteristics and applications of the injectors are described.