High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Exten...High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Extensive studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural materials.Synchrotron X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on materials.Recently,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation processes.In this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are discussed.The factors that influence the deformation mechanisms of HEAs are also outlined.This review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress changes.Perspectives on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed.展开更多
Shales are a major sink for K into seawater delivered from continental weathering,and are potential recorders of K cycling.High precision K isotope analyses reveal a[0.6%variation in δ^41K values(41K/39K relative to ...Shales are a major sink for K into seawater delivered from continental weathering,and are potential recorders of K cycling.High precision K isotope analyses reveal a[0.6%variation in δ^41K values(41K/39K relative to NIST SRM 3141a)from a set of well characterized postArchean Australian shale(PAAS)samples.By contrast,loess samples have relatively homogenous δ^41K values(-0.5±0.1%),which may represent the average K composition of upper continental crust.Most of the shales analyzed in this study have experienced K enrichment relative to average continental crust,and the majority of them define a trend of decreasing δ^41K value(from-0.5to-0.7%)with increasing K content and K/Na ratio,indicating cation exchange in clays minerals is accompanied by K isotope fractionation.Several shale samples do not follow the trend and have elevated δ^41K values up to-0.1%,and these samples are characterized by variable Fe isotope compositions,which reflect post-depositional processes.The K isotope variability observed in shales,in combination with recent findings about K isotope fractionation during continental weathering,indicates that K isotopes fractionate during cycling of K between different reservoirs,and K isotopes in sediments may be used to trace geological cycling of K.展开更多
With its more sustainable production mode and higher healthy food supplying,cultivated meat is gradually regarded as the promising alternative meat food in future by human beings.Most of the countries in the planet ha...With its more sustainable production mode and higher healthy food supplying,cultivated meat is gradually regarded as the promising alternative meat food in future by human beings.Most of the countries in the planet had participated in the cut-throat competition for sustainable protein searching,especially for the regions with low food self-sufficiency rate.In this paper,by reviewing the commercial market participation,product development stage,and technical research progress related to cultivated meat in detail,we demonstrated the industrialization progress of cultivated meat and explored the challenges of cultivated meat in the near future.1)Seeded cell and serum free medium were the basic raw materials,which were directly related to the food safety regulation,production cost control and productivity improvement;2)Bioreactor and regulation were the cornerstone of industrialization,which were closely related to the capacity expansion,product marketing;3)Technological improvements in taste,texture,safety,scale,cost were the foundation of realizing product iterative upgrade and market acceptance.展开更多
We develop a new ultrastrong medium Mn steel with a density reduced to 7.39 g cm^(-3).It has a novel tri-phase microstructure comprising a hierarchical martensitic matrix(α’),dispersed ultra-fine-retained austenite ...We develop a new ultrastrong medium Mn steel with a density reduced to 7.39 g cm^(-3).It has a novel tri-phase microstructure comprising a hierarchical martensitic matrix(α’),dispersed ultra-fine-retained austenite grains(γ),and both compressed and{200}orientedδ-ferrite lamellas,the latter’s formation is due to the alloying of high Al and Si contents for reducing density.As a result,both ultrahigh ultimate tensile strength of 2.1 GPa and good ductility of 16%are achieved after an extraordinary plastic strain hardening increment of about 1.4 GPa.The in-situ synchrotron-based high-energy(HE)X-ray diffraction(XRD)examinations during the tensile deformation revealed that the initial presence of residual com-pressive stress inδ-ferrite could increase the stress required to initiate the plastic tensile deformation of the specimen,leading to the isolatedδ-ferrite lamellas mostly deformed elastically to coordinate the plastic deformation of the martensitic matrix during yielding.During the plastic deformation,the gradual release of residual compressive stress inδandα’,the dislocation multiplication in all the three phases and the successiveγ-to-α’transformation all contribute to such a prominent work hardening increment.This study facilitates the development of novel strategies for fabricating ultrastrong but light steels.展开更多
An in situ high-energy X-ray diffraction(HE-XRD) technique was mainly used to investigate the micromechanical behavior of medium-Mn Fe-0.12 C-10.16 Mn-1.87 Al(in wt%) transformation-induced plasticit(TRIP) steel subje...An in situ high-energy X-ray diffraction(HE-XRD) technique was mainly used to investigate the micromechanical behavior of medium-Mn Fe-0.12 C-10.16 Mn-1.87 Al(in wt%) transformation-induced plasticit(TRIP) steel subjected to intercritical annealing at 625℃, 650℃, 675℃ and 700℃ for 1 h. As the intercritical annealing temperature increased, the volume fraction of retained austenite(RA) and ultimate tensilstress(UTS) increased, while the Lüders strain and yield stress(YS) decreased. The incremental workhardening exponent of experimental steel increased with increasing intercritical annealing temperatureThe overall trend of the transformation kinetics of the RA with respect to the true strain followed thsigmoidal shape predicted by the Olson and Cohen(OC) model. Load partitioning occurred among the ferrite, austenite and martensite immediately after entering the yielding stage. Because the stability of thRA decreased with increasing intercritical annealing temperature, the load undertaken by the martensitincreased. The moderate transformation kinetics of the RA and effective load partitioning among constituent phases were found to contribute to a favorable combination of strength and ductility for thimedium-Mn TRIP steel.展开更多
First-principle calculations,especially by the density functio nal theory(DFT),is used to study the structure and properties of oxygen/metal interfaces.Adsorption of oxygen molecules or atoms on metal surfaces plays a...First-principle calculations,especially by the density functio nal theory(DFT),is used to study the structure and properties of oxygen/metal interfaces.Adsorption of oxygen molecules or atoms on metal surfaces plays a key role in surface science and technology.This review is dedicated to the adsorption of oxygen molecules or atoms on metal surfaces and diffusion behavior from first-principle investigation.We hope that this review can provide some useful contributions to understa nd the study of adsorption properties and diffusion behavior on a metal surface at an atomic-scale,especially for those interested in catalytic oxidation and application of corrosion.展开更多
In this study, we performed an integrated investigation of K and Mg isotopes in hydrothermally altered rocks from the giant Dexing porphyry Cu deposit in China. Both the altered porphyry intrusion and the surrounding ...In this study, we performed an integrated investigation of K and Mg isotopes in hydrothermally altered rocks from the giant Dexing porphyry Cu deposit in China. Both the altered porphyry intrusion and the surrounding wall rocks exhibit large variations in K and Mg isotope compositions, with δ41K values ranging between-1.02‰ and 0.38‰, and δ26Mg values ranging between-0.49‰ and 0.32‰. The δ41K and δ26Mg values of the majority of altered samples are higher than the isotopic baseline values for upper continental crust. We attribute the general increase in δ41 K and δ26Mg in altered rocks to hydrothermal alteration,which caused preferential incorporation of heavy K and Mg isotopes in alteration products, particularly phyllosilicates. However,a few altered samples show anomalously low δ41K and δ26Mg values. The δ41K and δ26Mg values do not correlate with K and Mg concentrations, or mineralogy of altered samples. The variable K-Mg isotope data likely reflect fluids of different physicalchemical properties, or different isotopic compositions. Based on the combined K-Mg isotope data, at least three groups of hydrothermal fluids are distinguished from the Dexing porphyry deposit. Therefore, K-Mg isotopes are potentially a novel tracer for fingerprinting fluids in complex hydrothermal systems.展开更多
Cultured meat produced through in vitro cell culture technology is regarded as a technical revolution.In this study,three-dimensional(3D)bioprinting technology was used to mimic the growth environment in vivo and cons...Cultured meat produced through in vitro cell culture technology is regarded as a technical revolution.In this study,three-dimensional(3D)bioprinting technology was used to mimic the growth environment in vivo and construct a 3D culture system in vilro.Hydroge1 bioinks,namely,sodium alginate-gelatin and gelatin-methacrylate(GelMA)-silk fbroin,produced using two different curing processes were blended,and their rheological properties,mechanical properties,and biocompatibilities were compared.The 4%GelMA-20%silk fibroin hydroge1(GS2)demonstrated good performance and was hybridized with porcine skeleta1 muscle satellite cells for 3D printing to construct network structures of size 15 mm×15 mm and porosity 1000 um in 4-,6-,and 8-1ayer struchures.After 16 days of culture,4-and 6-1ayer grid structures formed compact muscle fbers organized by multinucleated myotubes.These results suggested that 3D bioprinting and GeIMA-silk fbroin hydrogels have great potential in fabricating porcine skeleta1 muscle tissue for use as cultured meat.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52171098 and 51921001)the State Key Laboratory for Advanced Metals and Materials(No.2022Z-02)+1 种基金the National High-level Personnel of Special Support Program(No.ZYZZ2021001)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-20-03C2 and FRF-BD-20-02B).
文摘High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Extensive studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural materials.Synchrotron X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on materials.Recently,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation processes.In this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are discussed.The factors that influence the deformation mechanisms of HEAs are also outlined.This review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress changes.Perspectives on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed.
基金supported by the National Key R&D Program of China (Project No. 2017YFC0602801)National Science Foundation of China (Grant Nos. 41622301, 41873004)+1 种基金supported by the NASA Astrobiology Institute (NNA13AA94A to BLB)the National Science Foundation (1741048-EAR to BLB)
文摘Shales are a major sink for K into seawater delivered from continental weathering,and are potential recorders of K cycling.High precision K isotope analyses reveal a[0.6%variation in δ^41K values(41K/39K relative to NIST SRM 3141a)from a set of well characterized postArchean Australian shale(PAAS)samples.By contrast,loess samples have relatively homogenous δ^41K values(-0.5±0.1%),which may represent the average K composition of upper continental crust.Most of the shales analyzed in this study have experienced K enrichment relative to average continental crust,and the majority of them define a trend of decreasing δ^41K value(from-0.5to-0.7%)with increasing K content and K/Na ratio,indicating cation exchange in clays minerals is accompanied by K isotope fractionation.Several shale samples do not follow the trend and have elevated δ^41K values up to-0.1%,and these samples are characterized by variable Fe isotope compositions,which reflect post-depositional processes.The K isotope variability observed in shales,in combination with recent findings about K isotope fractionation during continental weathering,indicates that K isotopes fractionate during cycling of K between different reservoirs,and K isotopes in sediments may be used to trace geological cycling of K.
基金the National Key Research and Development Program of China(2021YFC2101400)the Strategic Research and Consulting Project of Chinese Academy of Engineering(2022-XY-22)+1 种基金the Beijing Science and Technology Program(Z221100006422011)the Beijing Postdoctoral Science Foundation(2018-ZZ-119).
文摘With its more sustainable production mode and higher healthy food supplying,cultivated meat is gradually regarded as the promising alternative meat food in future by human beings.Most of the countries in the planet had participated in the cut-throat competition for sustainable protein searching,especially for the regions with low food self-sufficiency rate.In this paper,by reviewing the commercial market participation,product development stage,and technical research progress related to cultivated meat in detail,we demonstrated the industrialization progress of cultivated meat and explored the challenges of cultivated meat in the near future.1)Seeded cell and serum free medium were the basic raw materials,which were directly related to the food safety regulation,production cost control and productivity improvement;2)Bioreactor and regulation were the cornerstone of industrialization,which were closely related to the capacity expansion,product marketing;3)Technological improvements in taste,texture,safety,scale,cost were the foundation of realizing product iterative upgrade and market acceptance.
基金Haiwen Luo and Bin Hu acknowledge financial support from the National Natural Science Foundation of China(Nos.51831002,51904028 and 52233018)Fundamental Research Funds for the Central Universities(No.06500151)The present work is re-lated to awarded patents(No.201910244716.9 in China and No.US 10793932 in the USA).
文摘We develop a new ultrastrong medium Mn steel with a density reduced to 7.39 g cm^(-3).It has a novel tri-phase microstructure comprising a hierarchical martensitic matrix(α’),dispersed ultra-fine-retained austenite grains(γ),and both compressed and{200}orientedδ-ferrite lamellas,the latter’s formation is due to the alloying of high Al and Si contents for reducing density.As a result,both ultrahigh ultimate tensile strength of 2.1 GPa and good ductility of 16%are achieved after an extraordinary plastic strain hardening increment of about 1.4 GPa.The in-situ synchrotron-based high-energy(HE)X-ray diffraction(XRD)examinations during the tensile deformation revealed that the initial presence of residual com-pressive stress inδ-ferrite could increase the stress required to initiate the plastic tensile deformation of the specimen,leading to the isolatedδ-ferrite lamellas mostly deformed elastically to coordinate the plastic deformation of the martensitic matrix during yielding.During the plastic deformation,the gradual release of residual compressive stress inδandα’,the dislocation multiplication in all the three phases and the successiveγ-to-α’transformation all contribute to such a prominent work hardening increment.This study facilitates the development of novel strategies for fabricating ultrastrong but light steels.
基金supported by the National Key Research and Development Program of China (No. 2017YFA0403804)the National Natural Science Foundation of China (NSFC) (Nos. 51471032 and 51527801)+3 种基金the Fundamental Research Funds for the Central Universities (Nos. 06111020 and 06111040)the State Key Laboratory for Advanced Metals and Materials (Nos. 2016Z-01, 2016Z-12, and 2016Z-19)financial support from the Chinese Scholarship Council (CSC)supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences (No. DE-AC02-06CH11357)
文摘An in situ high-energy X-ray diffraction(HE-XRD) technique was mainly used to investigate the micromechanical behavior of medium-Mn Fe-0.12 C-10.16 Mn-1.87 Al(in wt%) transformation-induced plasticit(TRIP) steel subjected to intercritical annealing at 625℃, 650℃, 675℃ and 700℃ for 1 h. As the intercritical annealing temperature increased, the volume fraction of retained austenite(RA) and ultimate tensilstress(UTS) increased, while the Lüders strain and yield stress(YS) decreased. The incremental workhardening exponent of experimental steel increased with increasing intercritical annealing temperatureThe overall trend of the transformation kinetics of the RA with respect to the true strain followed thsigmoidal shape predicted by the Olson and Cohen(OC) model. Load partitioning occurred among the ferrite, austenite and martensite immediately after entering the yielding stage. Because the stability of thRA decreased with increasing intercritical annealing temperature, the load undertaken by the martensitincreased. The moderate transformation kinetics of the RA and effective load partitioning among constituent phases were found to contribute to a favorable combination of strength and ductility for thimedium-Mn TRIP steel.
基金supported by the National Key R&D Program of China(Nos.2017YFB0305600 and 2017YFB0306000)the Fok Ying Tung Education Foundation(No.171101)the Youth Innovation Team of Shaanxi Universities(No.2019-2022)。
文摘First-principle calculations,especially by the density functio nal theory(DFT),is used to study the structure and properties of oxygen/metal interfaces.Adsorption of oxygen molecules or atoms on metal surfaces plays a key role in surface science and technology.This review is dedicated to the adsorption of oxygen molecules or atoms on metal surfaces and diffusion behavior from first-principle investigation.We hope that this review can provide some useful contributions to understa nd the study of adsorption properties and diffusion behavior on a metal surface at an atomic-scale,especially for those interested in catalytic oxidation and application of corrosion.
基金supported by the National Key R & D Program of China (Grant No. 2018YFC0604106)the National Natural Science Foundation of China (Grant Nos. 41622301, 41873004)
文摘In this study, we performed an integrated investigation of K and Mg isotopes in hydrothermally altered rocks from the giant Dexing porphyry Cu deposit in China. Both the altered porphyry intrusion and the surrounding wall rocks exhibit large variations in K and Mg isotope compositions, with δ41K values ranging between-1.02‰ and 0.38‰, and δ26Mg values ranging between-0.49‰ and 0.32‰. The δ41K and δ26Mg values of the majority of altered samples are higher than the isotopic baseline values for upper continental crust. We attribute the general increase in δ41 K and δ26Mg in altered rocks to hydrothermal alteration,which caused preferential incorporation of heavy K and Mg isotopes in alteration products, particularly phyllosilicates. However,a few altered samples show anomalously low δ41K and δ26Mg values. The δ41K and δ26Mg values do not correlate with K and Mg concentrations, or mineralogy of altered samples. The variable K-Mg isotope data likely reflect fluids of different physicalchemical properties, or different isotopic compositions. Based on the combined K-Mg isotope data, at least three groups of hydrothermal fluids are distinguished from the Dexing porphyry deposit. Therefore, K-Mg isotopes are potentially a novel tracer for fingerprinting fluids in complex hydrothermal systems.
文摘Cultured meat produced through in vitro cell culture technology is regarded as a technical revolution.In this study,three-dimensional(3D)bioprinting technology was used to mimic the growth environment in vivo and construct a 3D culture system in vilro.Hydroge1 bioinks,namely,sodium alginate-gelatin and gelatin-methacrylate(GelMA)-silk fbroin,produced using two different curing processes were blended,and their rheological properties,mechanical properties,and biocompatibilities were compared.The 4%GelMA-20%silk fibroin hydroge1(GS2)demonstrated good performance and was hybridized with porcine skeleta1 muscle satellite cells for 3D printing to construct network structures of size 15 mm×15 mm and porosity 1000 um in 4-,6-,and 8-1ayer struchures.After 16 days of culture,4-and 6-1ayer grid structures formed compact muscle fbers organized by multinucleated myotubes.These results suggested that 3D bioprinting and GeIMA-silk fbroin hydrogels have great potential in fabricating porcine skeleta1 muscle tissue for use as cultured meat.