Understanding the phase equilibria of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system is essential for the efficient recycling of stainless steel pickling sludge.The isothermal section of this system at 1473 K under oxygen par...Understanding the phase equilibria of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system is essential for the efficient recycling of stainless steel pickling sludge.The isothermal section of this system at 1473 K under oxygen partial pressure of 0.15 Pa was investigated.Key experiments on the relevant binary systems were conducted using a combination of equilibrium-quenching techniques,X-ray diffraction,high-resolution transmission electron microscope,and electron probe microanalysis.These systems were rigorously assessed using the CALPHAD(CALculation of Phase Diagram)method,incorporating the present experimental data.The liquid phase was modeled using the ionic two-sublattice model,represented as(Ca^(2+),Cr^(3+),Fe^(2+))P(O_(2)^(-),Va,FeO_(1.5))Q,where Va represents vacancy,and P and Q denote the number of sites on the cation and anion sublattices,respectively.To ensure electroneutrality,the values of P and Q adjust according to the composition of the mixture.From this,the isothermal section of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system at 1473 K under the specified oxygen partial pressure was obtained based on the thermodynamic parameters of the binary systems.The present experimental data and calculation results hold significant implications for the comprehensive recycling of stainless steel pickling sludge.展开更多
A single-phase Nd_(2)Fe_(14)B powder was prepared from end-of-life(EOL)wind turbine magnets by a combination of hydrogen processing of magnetic scrap(HPMS)and selective leaching with citric acid.The impact of leaching...A single-phase Nd_(2)Fe_(14)B powder was prepared from end-of-life(EOL)wind turbine magnets by a combination of hydrogen processing of magnetic scrap(HPMS)and selective leaching with citric acid.The impact of leaching time on chemical composition,particle size and magnetic properties was investigated.Due to the low reduction potential of rare earth element(REE),the Nd-rich phase was preferentially leached.The use of an acid concentration of 0.5 mol/L,a solid to liquid ratio of 1/10 and a leaching time of 30 min was sufficient to leach the Nd-rich phase.Atomic resolution transmission electron microscopy was employed to examine the surface structure and chemistry of the leached Nd_(2)Fe_(14)B powder.It is revealed that the leaching process affects not only the Nd-rich phase but also the matrix grains,resulting in the formation of a predominant oxygen-rich amorphous reaction layer,25 nm thick.However,the oxygen content is reduced from 3500 to 2500 ppm and the magnetic saturation is increased by 8%.This method is a promising addition to the HPMS process,as the powder can be mixed with fresh,unoxidized grain boundary phase to produce recycled magnets with high remanence.展开更多
Precipitation-hardening in fcc-based high-entro py alloys(HEAs)have usually been realized by introducing complex intermetallic compounds.In this study,enhanced strength is ascribed to the existence of L1_(2) precipita...Precipitation-hardening in fcc-based high-entro py alloys(HEAs)have usually been realized by introducing complex intermetallic compounds.In this study,enhanced strength is ascribed to the existence of L1_(2) precipitates and B2/bcc conjoint phases in the fcc matrix.The nano-size particles in the Al_(0.5)CoCrFeNi HEA are produced by cold-rolling,followed by intermediate-temperature-annealing at 650℃.For L1_(2) ordering,the initial granular structure has transformed into lamella structure and then kept stable when the holding time prolonged to 200 h.The formation of this conjoint B2/bcc driven by the concentration profiles takes place when the diffusion process of elements is sufficient after long-time aging.Based on the microstructure analysis,changes in mechanical properties are associated with the shape,size scale and volume fraction of the precipitates.The peak ultimate tensile stress reaches 1221.5 MPa,1.97 times compared with the as-cast alloy,remaining plasticity of 21.3%.展开更多
This review summarizes the recent advances on the application of ^(57)Fe Mössbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine st...This review summarizes the recent advances on the application of ^(57)Fe Mössbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine structures of the Ce_(2)Fe_(14)B,(Ce,Nd)_(2)Fe_(14)B and MM_(2)Fe_(14)B phases are well-defined by using the model based on the Wigner-Seitz analysis of the crystal structure. The results show that the isomer shift δ and the quadrupole splitting öEQ of those 2:14:1 phases show minor changes with the Nd content, while the hyperfine field Bhfincreases monotonically with increasing Nd content and its value is influenced by the element segregation and phase separation in the 2:14:1 phase. Then, the hyperfine structures of the low fraction secondary phases are determined by the ^(57)Fe Mössbauer spectrometry due to its high sensitivity. On this basis,the content, magnetic behavior, and magnetization of the REFe_(2) phase, the amorphous grain boundary(GB) phase, and the amorphous worm-like phase, as well as their effects on the magnetic properties, are systematically studied.展开更多
Cyclin-dependent kinase 1 (CDK1) plays an essential role in cell cycle regulation.However,as mouse Cdk1embryos die early,the role of CDK1 in regulating the cell cycle and embryo development remains unclear.Here,we sho...Cyclin-dependent kinase 1 (CDK1) plays an essential role in cell cycle regulation.However,as mouse Cdk1embryos die early,the role of CDK1 in regulating the cell cycle and embryo development remains unclear.Here,we showed that zebrafish cdk1^(-/-)embryos exhibit severe microphthalmia accompanied by multiple defects in S phase entry,M phase progression,and cell differentiation but not in interkinetic nuclear migration.We identified Top2a as a potential downstream target and cyclin A2 and cyclin B1 as partners of Cdk1 in cell cycle regulation via an in silico analysis.While depletion of either cyclin A2 or Top2a led to the decreased S phase entry in zebrafish retinal cells,the depletion of cyclin B1 led to M phase arrest.Moreover,phosphorylation of Top2a at serine 1213 (S1213) was nearly abolished in both cdk1 and ccna2mutants,but not in ccnb1 mutants.Furthermore,overexpression of TOP2A^(S1213D),the phosphomimetic form of human TOP2A,rescued S phase entry and alleviated the microphthalmia defects in both cdk1^(-/-)and ccna2^(-/-)embryos.Taken together,our data suggest that Cdk1 interacts with cyclin A2 to regulate S phase entry partially through Top2a phosphorylation and interacts with cyclin B1 to regulate M phase progression.展开更多
We systematically investigate the effect of pressure on the magnetic properties of GdCo2B2 on the basis of alternating current（AC） susceptibility,AC heat capacity and electrical resistivity measurements under pressu...We systematically investigate the effect of pressure on the magnetic properties of GdCo2B2 on the basis of alternating current（AC） susceptibility,AC heat capacity and electrical resistivity measurements under pressures up to 2.2 GPa.A detailed magnetic phase diagram under pressure is determined.GdCo2B2 exhibits three anomalies that apparently reflect magnetic phase transitions,respectively,at temperatures TC= 20.5 K,T1= 18.0 K and TN= 11.5 K under ambient pressure.Under pressures up to 2.2 GPa,these anomalies are observed to slightly increase at TCand T1,and they coincide with each other above 1.6 GPa.Conversely,they decrease at TN and disappear under pressures higher than 1.4 GPa.The results indicate that the low-temperature magnetic phases can be easily suppressed by pressure.Moreover,the spin-glass-like behavior of GdCo2B2 is examined in terms of magnetization,aging effect and frequency dependence of AC susceptibility.A separation between the zero-field-cooled（ZFC） and field-cooled（FC） magnetization curves becomes evident at a low magnetic field of 0.001 T.A long-time relaxation behavior is observed at 4 K.The freezing temperature Tfincreases with frequency increasing.展开更多
Residues of tetracycline antibiotics(TCs) in environments may be harmful to human.Due to their high polarities,it is extremely challenging to efficiently enrich TCs with low concentrations in natural waters for analys...Residues of tetracycline antibiotics(TCs) in environments may be harmful to human.Due to their high polarities,it is extremely challenging to efficiently enrich TCs with low concentrations in natural waters for analysis.In this work,a magnetic metal-organic framework Fe_(3)O_(4)@[Cu_(3)(btc)_(2)]was synthesized and applied as a dispersive micro-solid phase extraction adsorbent for TCs enrichment.Effects of dispersive micro-solid phase extraction conditions including extraction time,solution p H,and elution solvent on the extraction efficiencies of TCs were investigated.Results show that TCs could be enriched efficiently by Fe_(3)O_(4)@[Cu_(3)(btc)_(2)],and electrostatic interaction between TCs and Fe_(3)O_(4)@[Cu_(3)(btc)_(2)]dominated this process.Combined with liquid chromatography-tandem mass spectrometry,four TCs residues (oxytetracycline,tetracycline,chlortetracycline,and doxycycline) in natural waters were determined.The detection limits (LOD,S/N=3) of the four antibiotics were 0.01-0.02μg/L,and the limits of quantitation (LOQ,S/N=10)were 0.04-0.07μg/L.The recoveries obtained from river water and aquaculture water spiked with three TCs concentration levels ranged from 70.3%to 96.5%with relative standard deviations of 3.8%-12.8%.Results indicate that the magnetic metal-organic framework based dispersive micro-solid phase extraction is simple,rapid and high-loading for antibiotics enrichment from water,which further expand the practical application of metal-organic frameworks in sample pretreatment for environmental pollutant analysis.展开更多
Adding Al is an important strategy to obtain ultrahigh specific strength in BCC refractory high-entropy alloys(RHEAs).However,the main structure typically transitions from disordered BCC to ordered B2 with increasing ...Adding Al is an important strategy to obtain ultrahigh specific strength in BCC refractory high-entropy alloys(RHEAs).However,the main structure typically transitions from disordered BCC to ordered B2 with increasing Al concentration,leading to poor ductility.In the present study,a phase inversion in a high-Al-content B2-RHEA(Zr_(40)Ti_(28)Nb_(12)Al_(20))was systematically studied through thermo-mechanical treatment.The grains of the single B2 phase transformed inversely to the BCC+B2 microstructure with a dispersion of spherical B2 precipitates in the BCC grains.The evolution of the microstructure began with the decomposition of the B2 phase into Al-rich and Al-poor regions.The subsequent coarsening of the Al-rich B2 precipitates continuously consumes Al and Zr atoms from the solution.The depletion of Al and Zr in the matrix drives it to gradually form the disordered BCC structure and eventually transform to a single BCC phase matrix.This phase inversion enhanced tensile ductility of the RHEA while still maintaining its high specific strength.The current study provides a novel idea for inhibiting Al-induced brittleness of RHEAs at high Al content.展开更多
The melting behavior,solid state phase transformation and structure of pseudo-ternary compounds Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B were studied using differential thermal analysis,optical microscopy...The melting behavior,solid state phase transformation and structure of pseudo-ternary compounds Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B were studied using differential thermal analysis,optical microscopy X-ray diffraction,and electron probe micro-analysis techniques.At high temperature,eutectoid decomposition R_2(Ni,M)_(17)→R(Ni,M)_5+x-Ni(M) takes place in these two pseudo-ternary compounds,in the composition range x=0.6～1.0 and y=0.3～1.0,respectively.When x(or y)≤0.2,both Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B are single phase tetragonal.The phase constitutents of these two systems at room tempera- ture are similar in the composition range 0.6≤x(or y)≤1.0.展开更多
Based on the observation of temperature variation of both domain structure and magnetic con- trast.the thermal demagnetization and randomness of domain nucleation was discussed.
Bronze phase titanium dioxide(TiO_(2)(B))could be a promising high-power anode for lithium ion battery.However,TiO_(2)(B)is a metastable material,so the as-synthesized samples are inevitably accompanied by the existen...Bronze phase titanium dioxide(TiO_(2)(B))could be a promising high-power anode for lithium ion battery.However,TiO_(2)(B)is a metastable material,so the as-synthesized samples are inevitably accompanied by the existence of anatase phases.It has been found that the TiO_(2)(B)'s purity is positively correlated with its electrochemical performance.Herein,we have established an accurate quantification of the TiO_(2)(B)/anatase ratio,by figuring out the function between the purity of TiO_(2)(B)phase in the high purity range and its Raman spectra features in combination of the calibration by the synchrotron radiation X-ray diffraction(XRD).Compared with the time-consuming electrochemical method,the rapid,sensitive and non-destructive features of Raman spectroscopy have made it a promising candidate for determining the purity of TiO_(2)(B).Further,the correlations developed in this work should be instructive in synthesizing pure TiO_(2)(B)and furthermore optimizing its electrochemical charge storage properties.展开更多
基金supports on the Project 52274306 from the National Natural Science Foundation of China are gratefully acknowledged.
文摘Understanding the phase equilibria of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system is essential for the efficient recycling of stainless steel pickling sludge.The isothermal section of this system at 1473 K under oxygen partial pressure of 0.15 Pa was investigated.Key experiments on the relevant binary systems were conducted using a combination of equilibrium-quenching techniques,X-ray diffraction,high-resolution transmission electron microscope,and electron probe microanalysis.These systems were rigorously assessed using the CALPHAD(CALculation of Phase Diagram)method,incorporating the present experimental data.The liquid phase was modeled using the ionic two-sublattice model,represented as(Ca^(2+),Cr^(3+),Fe^(2+))P(O_(2)^(-),Va,FeO_(1.5))Q,where Va represents vacancy,and P and Q denote the number of sites on the cation and anion sublattices,respectively.To ensure electroneutrality,the values of P and Q adjust according to the composition of the mixture.From this,the isothermal section of the Fe_(3)O_(4)-Cr_(2)O_(3)-CaO system at 1473 K under the specified oxygen partial pressure was obtained based on the thermodynamic parameters of the binary systems.The present experimental data and calculation results hold significant implications for the comprehensive recycling of stainless steel pickling sludge.
基金Project supported by the German Federal Ministry of Education and Research as part of the program"FH-Kooperativ"the European Commission under the Horizon Europe Research and Innovation Program(101058598)。
文摘A single-phase Nd_(2)Fe_(14)B powder was prepared from end-of-life(EOL)wind turbine magnets by a combination of hydrogen processing of magnetic scrap(HPMS)and selective leaching with citric acid.The impact of leaching time on chemical composition,particle size and magnetic properties was investigated.Due to the low reduction potential of rare earth element(REE),the Nd-rich phase was preferentially leached.The use of an acid concentration of 0.5 mol/L,a solid to liquid ratio of 1/10 and a leaching time of 30 min was sufficient to leach the Nd-rich phase.Atomic resolution transmission electron microscopy was employed to examine the surface structure and chemistry of the leached Nd_(2)Fe_(14)B powder.It is revealed that the leaching process affects not only the Nd-rich phase but also the matrix grains,resulting in the formation of a predominant oxygen-rich amorphous reaction layer,25 nm thick.However,the oxygen content is reduced from 3500 to 2500 ppm and the magnetic saturation is increased by 8%.This method is a promising addition to the HPMS process,as the powder can be mixed with fresh,unoxidized grain boundary phase to produce recycled magnets with high remanence.
基金supported financially by the National Natural Science Foundation of China(Nos.51774240 and 51571161)the fund of the State Key Laboratory of Solidification Processing in NWPU(No.2019-TS-04)the National Training Program of Innovation and Entrepreneurship for Undergraduates(No.201910699109)。
文摘Precipitation-hardening in fcc-based high-entro py alloys(HEAs)have usually been realized by introducing complex intermetallic compounds.In this study,enhanced strength is ascribed to the existence of L1_(2) precipitates and B2/bcc conjoint phases in the fcc matrix.The nano-size particles in the Al_(0.5)CoCrFeNi HEA are produced by cold-rolling,followed by intermediate-temperature-annealing at 650℃.For L1_(2) ordering,the initial granular structure has transformed into lamella structure and then kept stable when the holding time prolonged to 200 h.The formation of this conjoint B2/bcc driven by the concentration profiles takes place when the diffusion process of elements is sufficient after long-time aging.Based on the microstructure analysis,changes in mechanical properties are associated with the shape,size scale and volume fraction of the precipitates.The peak ultimate tensile stress reaches 1221.5 MPa,1.97 times compared with the as-cast alloy,remaining plasticity of 21.3%.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LY20E010002,LR18E010001,and LD19E010001)the National Natural Science Foundation of China(Grant Nos.U1704253 and 51801047)+2 种基金Liaoning Revitalization Talents Program(Grant No.XLYC1807177)the Key Research and Development plan of Zhejiang Province,China(Grant No.2020C05014)Ten Thousand Talents Plan of Zhejiang Province,China(Grant No.2018R52003)。
文摘This review summarizes the recent advances on the application of ^(57)Fe Mössbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine structures of the Ce_(2)Fe_(14)B,(Ce,Nd)_(2)Fe_(14)B and MM_(2)Fe_(14)B phases are well-defined by using the model based on the Wigner-Seitz analysis of the crystal structure. The results show that the isomer shift δ and the quadrupole splitting öEQ of those 2:14:1 phases show minor changes with the Nd content, while the hyperfine field Bhfincreases monotonically with increasing Nd content and its value is influenced by the element segregation and phase separation in the 2:14:1 phase. Then, the hyperfine structures of the low fraction secondary phases are determined by the ^(57)Fe Mössbauer spectrometry due to its high sensitivity. On this basis,the content, magnetic behavior, and magnetization of the REFe_(2) phase, the amorphous grain boundary(GB) phase, and the amorphous worm-like phase, as well as their effects on the magnetic properties, are systematically studied.
基金supported by grants from the National Key Research and Development Program of China (2017YFA0104600)the National Natural Science Foundation of China (31970767, 31771597 and 31571515)+1 种基金the National Basic Research Program of China (973 Program 2012CB966601 and 2013CB945300)the Ministry of Science and Technology of the People’s Republic of China (2011DFB30010)。
文摘Cyclin-dependent kinase 1 (CDK1) plays an essential role in cell cycle regulation.However,as mouse Cdk1embryos die early,the role of CDK1 in regulating the cell cycle and embryo development remains unclear.Here,we showed that zebrafish cdk1^(-/-)embryos exhibit severe microphthalmia accompanied by multiple defects in S phase entry,M phase progression,and cell differentiation but not in interkinetic nuclear migration.We identified Top2a as a potential downstream target and cyclin A2 and cyclin B1 as partners of Cdk1 in cell cycle regulation via an in silico analysis.While depletion of either cyclin A2 or Top2a led to the decreased S phase entry in zebrafish retinal cells,the depletion of cyclin B1 led to M phase arrest.Moreover,phosphorylation of Top2a at serine 1213 (S1213) was nearly abolished in both cdk1 and ccna2mutants,but not in ccnb1 mutants.Furthermore,overexpression of TOP2A^(S1213D),the phosphomimetic form of human TOP2A,rescued S phase entry and alleviated the microphthalmia defects in both cdk1^(-/-)and ccna2^(-/-)embryos.Taken together,our data suggest that Cdk1 interacts with cyclin A2 to regulate S phase entry partially through Top2a phosphorylation and interacts with cyclin B1 to regulate M phase progression.
基金Project supported by JSPS KAKENHI(Grant No.24540366,Grant-in-Aid for Scientific Research(C))
文摘We systematically investigate the effect of pressure on the magnetic properties of GdCo2B2 on the basis of alternating current（AC） susceptibility,AC heat capacity and electrical resistivity measurements under pressures up to 2.2 GPa.A detailed magnetic phase diagram under pressure is determined.GdCo2B2 exhibits three anomalies that apparently reflect magnetic phase transitions,respectively,at temperatures TC= 20.5 K,T1= 18.0 K and TN= 11.5 K under ambient pressure.Under pressures up to 2.2 GPa,these anomalies are observed to slightly increase at TCand T1,and they coincide with each other above 1.6 GPa.Conversely,they decrease at TN and disappear under pressures higher than 1.4 GPa.The results indicate that the low-temperature magnetic phases can be easily suppressed by pressure.Moreover,the spin-glass-like behavior of GdCo2B2 is examined in terms of magnetization,aging effect and frequency dependence of AC susceptibility.A separation between the zero-field-cooled（ZFC） and field-cooled（FC） magnetization curves becomes evident at a low magnetic field of 0.001 T.A long-time relaxation behavior is observed at 4 K.The freezing temperature Tfincreases with frequency increasing.
基金supported by the National Natural Science Foundation of China(No.21607003).
文摘Residues of tetracycline antibiotics(TCs) in environments may be harmful to human.Due to their high polarities,it is extremely challenging to efficiently enrich TCs with low concentrations in natural waters for analysis.In this work,a magnetic metal-organic framework Fe_(3)O_(4)@[Cu_(3)(btc)_(2)]was synthesized and applied as a dispersive micro-solid phase extraction adsorbent for TCs enrichment.Effects of dispersive micro-solid phase extraction conditions including extraction time,solution p H,and elution solvent on the extraction efficiencies of TCs were investigated.Results show that TCs could be enriched efficiently by Fe_(3)O_(4)@[Cu_(3)(btc)_(2)],and electrostatic interaction between TCs and Fe_(3)O_(4)@[Cu_(3)(btc)_(2)]dominated this process.Combined with liquid chromatography-tandem mass spectrometry,four TCs residues (oxytetracycline,tetracycline,chlortetracycline,and doxycycline) in natural waters were determined.The detection limits (LOD,S/N=3) of the four antibiotics were 0.01-0.02μg/L,and the limits of quantitation (LOQ,S/N=10)were 0.04-0.07μg/L.The recoveries obtained from river water and aquaculture water spiked with three TCs concentration levels ranged from 70.3%to 96.5%with relative standard deviations of 3.8%-12.8%.Results indicate that the magnetic metal-organic framework based dispersive micro-solid phase extraction is simple,rapid and high-loading for antibiotics enrichment from water,which further expand the practical application of metal-organic frameworks in sample pretreatment for environmental pollutant analysis.
基金support from the National Key Research and Development Program of China (No.2017YFB0702003)the National Natural Science Foundation of China (No.51871217)+2 种基金Yong Zhang thanks the Guangdong Basic and Applied Basic Research Foundation (No.2019B1515120020)the State Key Laboratory for Advanced Metals and Materials in the University of Science and Technology Beijing (No.2020Z-08)the Funds for Creative Research Groups of China (No.51921001).
文摘Adding Al is an important strategy to obtain ultrahigh specific strength in BCC refractory high-entropy alloys(RHEAs).However,the main structure typically transitions from disordered BCC to ordered B2 with increasing Al concentration,leading to poor ductility.In the present study,a phase inversion in a high-Al-content B2-RHEA(Zr_(40)Ti_(28)Nb_(12)Al_(20))was systematically studied through thermo-mechanical treatment.The grains of the single B2 phase transformed inversely to the BCC+B2 microstructure with a dispersion of spherical B2 precipitates in the BCC grains.The evolution of the microstructure began with the decomposition of the B2 phase into Al-rich and Al-poor regions.The subsequent coarsening of the Al-rich B2 precipitates continuously consumes Al and Zr atoms from the solution.The depletion of Al and Zr in the matrix drives it to gradually form the disordered BCC structure and eventually transform to a single BCC phase matrix.This phase inversion enhanced tensile ductility of the RHEA while still maintaining its high specific strength.The current study provides a novel idea for inhibiting Al-induced brittleness of RHEAs at high Al content.
基金the National Natural Science Fundation of China.
文摘The melting behavior,solid state phase transformation and structure of pseudo-ternary compounds Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B were studied using differential thermal analysis,optical microscopy X-ray diffraction,and electron probe micro-analysis techniques.At high temperature,eutectoid decomposition R_2(Ni,M)_(17)→R(Ni,M)_5+x-Ni(M) takes place in these two pseudo-ternary compounds,in the composition range x=0.6～1.0 and y=0.3～1.0,respectively.When x(or y)≤0.2,both Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B are single phase tetragonal.The phase constitutents of these two systems at room tempera- ture are similar in the composition range 0.6≤x(or y)≤1.0.
文摘Based on the observation of temperature variation of both domain structure and magnetic con- trast.the thermal demagnetization and randomness of domain nucleation was discussed.
基金This work was financially supported by the National Natural Science Foundation of China(22075074)Outstanding Young Scientists Research Funds from Hunan Province(2020JJ2004)+3 种基金Major Science and Technology Program of Hunan Province(2020WK2013)Natural Science Foundation of Hunan Province(2020JJ5035)National Natural Science Foundation of China(Grant No.11704185)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(SKL201802SIC).
文摘Bronze phase titanium dioxide(TiO_(2)(B))could be a promising high-power anode for lithium ion battery.However,TiO_(2)(B)is a metastable material,so the as-synthesized samples are inevitably accompanied by the existence of anatase phases.It has been found that the TiO_(2)(B)'s purity is positively correlated with its electrochemical performance.Herein,we have established an accurate quantification of the TiO_(2)(B)/anatase ratio,by figuring out the function between the purity of TiO_(2)(B)phase in the high purity range and its Raman spectra features in combination of the calibration by the synchrotron radiation X-ray diffraction(XRD).Compared with the time-consuming electrochemical method,the rapid,sensitive and non-destructive features of Raman spectroscopy have made it a promising candidate for determining the purity of TiO_(2)(B).Further,the correlations developed in this work should be instructive in synthesizing pure TiO_(2)(B)and furthermore optimizing its electrochemical charge storage properties.
