The phase equilibria relationship of the system RbCl-PEG6000-H2O were investigated at temperatures of 288.2,298.2,and 308.2 K,the compositions of solid-liquid equilibria(SLE)and liquid-liquid equilibria(LLE)were deter...The phase equilibria relationship of the system RbCl-PEG6000-H2O were investigated at temperatures of 288.2,298.2,and 308.2 K,the compositions of solid-liquid equilibria(SLE)and liquid-liquid equilibria(LLE)were determined.The complete phase diagrams,binodal curve diagrams,and tie-line diagrams were all plotted.Results show that both solid-liquid equilibria and liquid-liquid equilibria relationships at each studied temperature.The complete phase diagrams at 288.2 K,298.2 K and 308.2 K consist of six phase regions:unsaturated liquid region(L),two saturated solutions with one solid phase of RbCl(L_S),one saturated liquid phase with two solid phases of PEG6000 and RbCl(2S+L),an aqueous two-phase region(2L),and a region with two liquids and one solid phase of RbCl(2L_S).With the increase in temperature,the layering ability of the aqueous two-phase system increases,and both regions(2L)and(2L_S)increase.The binodal curves were fitted using the nonlinear equations proposed by Mistry,Hu,and Jayapal.Additionally,the tie-line data were correlated with the Othmer-Tobias,Bancroft,Hand,and Bachman equations.The liquid-liquid equilibria at 288.2 K,298.2 K and 308.2 K were calculated using the NRTL model.The findings confirm that the experimental and calculated values are in close agreement,demonstrating the model’s effectiveness in representing the system’s behavior.展开更多
The availability of a tremendous amount of seismic data demands seismological researchers to analyze seismic phases efficiently.Recently,deep learning algorithms exhibit a powerful capability of detecting and picking ...The availability of a tremendous amount of seismic data demands seismological researchers to analyze seismic phases efficiently.Recently,deep learning algorithms exhibit a powerful capability of detecting and picking on P-and S-wave phases.However,it remains a challenge to effeciently process enormous teleseismic phases,which are crucial to probe Earth’s interior structures and their dynamics.In this study,we propose a scheme to detect and pick teleseismic phases,such as seismic phase that reflects off the core-mantle boundary(i.e.,PcP)and that reflects off the inner-core boundary(i.e.,PKiKP),from a seismic dataset in Japan.The scheme consists of three steps:1)latent phase traces are truncated from the whole seismogram with theoretical arrival times;2)latent phases are recognized and evaluated by convolutional neural network(CNN)models;3)arrivals of good or fair phase are picked with another CNN models.The testing detection result on 7386 seismograms shows that the scheme recognizes 92.15%and 94.13%of PcP and PKiKP phases.The testing picking result has a mean absolute error of 0.0742 s and 0.0636 s for the PcP and PKiKP phases,respectively.These seismograms were processed in just 5 min for phase detection and picking,demonstrating the efficiency of the proposed scheme in automatic teleseismic phase analysis.展开更多
Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopo...Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopolymers,swimming bacteria,artificial swimmers,and animal herds.In contrast to wet active matter,dry active matter is an active system characterized by the absence of significant hydrodynamic interactions and conserved momentum.In dry active matter,the role of surrounding fluids is providing viscous friction at low Reynolds numbers and can be neglected at high Reynolds numbers.This review offers a comprehensive overview of recent experimental,computational,and theoretical advances in understanding phase transitions and critical phenomena in dry aligning active matter,including polar particles,self-propelled rods,active nematics,and their chiral counterparts.Various ways of determining phase transition points as well as non-equilibrium phenomena,such as collective motion,cluster formation,and creation and annihilation of topological defects are reviewed.展开更多
A phase-field model integrated with the thermodynamic databases was constructed to investigate the impact of Ni content on the precipitation kinetics and phase transformation of the Cu-rich phase in Fe-Cu-Ni alloy at ...A phase-field model integrated with the thermodynamic databases was constructed to investigate the impact of Ni content on the precipitation kinetics and phase transformation of the Cu-rich phase in Fe-Cu-Ni alloy at 773 K.The results demonstrated that the Cu core-Ni shell structures form via the decomposition of Cu-Ni co-clusters,which is consistent with previous experimental results.As the Ni content increases,both the volume fraction and number density of Cu-rich precipitates increase,while their size decreases.With the increase in Ni content,the transformation from a Cu to 9R Cu is accelerated,which is the opposite to the result of increasing Mn content.Magnetic energy can increase the nucleation rate of the Cu-rich phase,but it does not affect the phase transformation driving force required for its crystal structure transformation.展开更多
As an advanced device for observing atmospheric winds,the spaceborne Doppler Asymmetric Spatial Heterodyne(DASH)interferometer also encounters challenges associated with phase distortion,par-ticularly in limb sounding...As an advanced device for observing atmospheric winds,the spaceborne Doppler Asymmetric Spatial Heterodyne(DASH)interferometer also encounters challenges associated with phase distortion,par-ticularly in limb sounding scenarios.This paper discusses interferogram modeling and phase distortion cor-rection techniques for spaceborne DASH interferometers.The modeling of phase distortion interferograms with and without Doppler shift for limb observation was conducted,and the effectiveness of the analytical expression was verified through numerical simulation.The simulation results indicate that errors propagate layer by layer while using the onion-peeling inversion algorithm to handle phase-distorted interferograms.In contrast,the phase distortion correction algorithm can achieve effective correction.This phase correction method can be successfully applied to correct phase distortions in the interferograms of the spaceborne DASH interferometer,providing a feasible solution to enhance its measurement accuracy.展开更多
The grain boundary diffusion process(GBDP)has proven to be an effective method for enhancing the coercivity of sintered Nd-Fe-B magnets.However,the limited diffusion depth and thicker shell struc-ture have impeded the...The grain boundary diffusion process(GBDP)has proven to be an effective method for enhancing the coercivity of sintered Nd-Fe-B magnets.However,the limited diffusion depth and thicker shell struc-ture have impeded the further development of magnetic properties.Currently,the primary debates re-garding the mechanism of GBDP with Tb revolve around the dissolution-solidification mechanism and the atomic substitution mechanism.To clarify this mechanism,the microstructure evolution of sintered Nd-Fe-B magnets during the heating process of GBDP has been systematically studied by quenching at different tem peratures.In this study,it was found that the formation of TbFe_(2) phase is related to the dis-solution of _(2)Fe_(14)B grains during GBDP with Tb.The theory of mixing heat and phase separation further confirms that the Nd_(2)Fe_(14)B phase dissolves to form a mixed phase of Nd and TbFe_(2),which then solidifies into the(Nd,Tb)_(2)Fe_(14)B phase.Based on the discovery of the TbFe_(2) phase,the dissolution-solidification mechanism is considered the primary mechanism for GBDP.This is supported by the elemental content of the two typical core-shell structures observed.展开更多
The field of Neurorestoratology is steadily growing.The developmental phases and current key tasks are presented below:Neurorestoratology development divides into four phases,Preparation,Incubation,Growth,and Maturity...The field of Neurorestoratology is steadily growing.The developmental phases and current key tasks are presented below:Neurorestoratology development divides into four phases,Preparation,Incubation,Growth,and Maturity.1 The characteristics of the Preparation phase.展开更多
Organic ferroelastics with metal free features and intrinsically light weight are highly desirable for future applications in flexible,smart and biocompatible devices.However,organoferroelastics with plastic phase tra...Organic ferroelastics with metal free features and intrinsically light weight are highly desirable for future applications in flexible,smart and biocompatible devices.However,organoferroelastics with plastic phase transition have rarely been reported yet.Herein,we discovered ferroelasticity in a pair of organic enantiomers,(1S and/or 1R)-2,10-camphorsultam(S-and R-CPS),which undergoes a high-T_(c)plastic phase transition.Both large entropies change of∼45 J mol^(-1)K^(-1)and evidently ductile deformation process confirm the plastic phase feature.Strip-like ferroelastic domain patterns and bidirectional domain movements have been observed via polarized light microscopy and nanoindentation technique,respectively.This work highlights the discovery of organic ferroelastic combining the features of enantiomers and plastic phase transition,which contributes insights into exploration of organic multifunctional materials.展开更多
In this paper,three magnetrons with each of them having specifically designed multiple coupling ports,which deliver specific power distribution for developing a magnetron array based on efficient phase locking between...In this paper,three magnetrons with each of them having specifically designed multiple coupling ports,which deliver specific power distribution for developing a magnetron array based on efficient phase locking between them,are proposed to produce high powerμs-level pulses.To demonstrate the effectiveness of the magnetron with one and two coupling ports as a unit for efficient phase locking,we designed experimentally the coupling ports delivering~10%(the power distribution ratio)of the output power of the magnetron for coupling with other magnetron units.The effect of one and two coupling ports on the operating capability,including the power distribution ratio,anode current and frequency,is demonstrated by establishing an equivalent experimental model which can characterize an ideal operation of the array.The experimental results show that the power distribution ratio is~9%for the magnetron with one coupling port,and~12.5%(coupling port 1,2)for the magnetron with two coupling ports.This shows good uniformity of the coupling capability of the two coupling ports and provides guidance for optimizing the power distribution ratio of multiport magnetron units,which are critical for efficient phase locking in the proposed array in future and higher power arrays.展开更多
TiAl alloys with the(α2+γ)lamellar structure are highly valued for their excellent high-temperature strength and creep resistance.Understanding the formation mechanism of the lamellar structure is crucial for tuning...TiAl alloys with the(α2+γ)lamellar structure are highly valued for their excellent high-temperature strength and creep resistance.Understanding the formation mechanism of the lamellar structure is crucial for tuning the microstructure and properties.This work investigates the formation of lamellar structure in Ti-48AI-7Nb-2.5V-1Cr alloy,revealing the presence of hcp-based long-period superstructure(hcp-LPS)as a metastable phase during lamellar formation.The identification of hcp-LPS demonstrates that the necessary solute enrichment for the formation ofγlamellae occurs on the hexagonalαmatrix,implying that phase separation ofα→Al-richαlamellae+Al-depletedαlamellae is the first step of lamellar formation.Once phase separation is completed,all subsequent phase transitions occur within the Al-richαlamellae.Additionally,the formation of twin lamellae is further discussed.The formation of the twin lamellae occurs sequentially.Pre-existing lamella promotes the formation of later lamella by inducing so-lute enrichment in its surrounding region,and then the successive slip of Shockley partial dislocations with opposite Burgers vectors ensures special stacking of later lamellae.These findings not only con-tribute to the fundamental understanding of spinodal mechanisms in hexagonal crystals,but also provide novel insights into the formation of twin lamellae.展开更多
Mg-Zn-Mn alloys have the advantages of low cost,excellent mechanical properties,and high corrosion resistance.To clarify the phase equilibria of Mg-Zn-Mn alloy in the Mg-rich corners,the present work experimentally in...Mg-Zn-Mn alloys have the advantages of low cost,excellent mechanical properties,and high corrosion resistance.To clarify the phase equilibria of Mg-Zn-Mn alloy in the Mg-rich corners,the present work experimentally investigated the phase equilibria in the Mg-rich corner at 300-400°C with equilibrated alloy method using electron probe micro analyzer(EPMA),X-ray diffractometer(XRD),transmission electron microscopy(TEM),and differential scanning calorimeter(DSC).Mn atoms were found to dissolve into MgZn_(2) to form a ternary solid-solution type compound,in which Mn content can be up to 15.1at%at 400°C.Three-phase equilibrium ofα-Mg+MgZn_(2)+α-Mn and liquid+α-Mg+MgZn_(2) were confirmed at 400°C.Subsequently,thermodynamic modeling of the Mg-Zn-Mn system was carried out using the CALPHAD method based on the experimental data of this work and literature data.The calculated invariant reaction Liquid+α-Mn→α-Mg+MgZn_(2) at 430°C shows good agreement with the DSC results.In addition,the results of solidification path calculations explain the microstructure in the ascast and annealed alloys well.The agreement between the calculated results and experimental data proves the self-consistency of the thermodynamic database,which can provide guidance for the compositional design of Mg-Zn-Mn alloys.展开更多
The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 9...The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 925 ℃. Below 925 ℃, the volume fraction of secondary Laves phases increases with the rise of the temperature, and its morphology changes from granular to thin-film;above 925 ℃, the volume fraction of secondary Laves phases shows an opposite trend to temperature, and its morphology changes from thin-film to granular. A detailed explanation through linear density (ρ) is provided that the influence of secondary Laves phases at the grain boundaries (GBs) on notch sensitivity depends on the coupling competition effect of their size, quantity, and morphology. Notably, the granular Laves phases are more beneficial to improving the notch sensitivity of the alloy compared with thin-film Laves phases. Granular secondary Laves phases can promote the formation of γ′ phases depletion zone to improve the ability of GBs to accommodate high strain localization, and effectively inhibit the crack initiation and propagation.展开更多
A novel approach for fabricating multi-principal element alloys with adjustable phase configurations and mechanical properties was developed using laser-aided additive manufacturing(LAAM),combining FCC-structured(face...A novel approach for fabricating multi-principal element alloys with adjustable phase configurations and mechanical properties was developed using laser-aided additive manufacturing(LAAM),combining FCC-structured(face-centered cubic)CoCrNi and BCC-structured(body-centered cubic)CoCrNiAl0.6TiFe feedstocks.During fabrication,CoCrNi powders and CoCrNiAl0.6TiFe powders were simultaneously fed into the melt pool at individually adjustable rates,allowing for controlled phase transitions.The resulting phase evolution demonstrated a gradual transition from a single FCC structure CoCrNi(A10.6TiFe)x(x=0,0.1,0.2,0.3)to a dual FCCB2 structure CoCrNi(Al0.6TiFe)x(x=0.4,0.5)as the proportion of BCC-structured powders increased.The B2 phase,enriched in Ti and Al due to their larger atomic radii and negative segregation enthalpy,precipitated around the FCC matrix,with volume fractions of 0.5%and 5.7%for CoCrNi(A10.6TiFe)0.4 and CoCrNi(A10.6TiFe)0.5,respectively.This phase transition resulted in significant mechanical enhancements.Yield and ultimate tensile strengths increased from 486.0 and 781.2 MPa(CoCrNi)to 887.2 and 1165.2 MPa(CoCrNi(A10.6TiFe)0.5).Dislocation-mediated hardening prevailed in single-phase FCC alloys,exhibiting a characteristic dislocation density of 2.5×10^(15)m^(-2)for CoCrNi(A10.6TiFe)0.3 alloy.Once the B2 phase precipitated,precipitation strengthening became dominant,as observed in transmission electron microscopy(TEM),where dislocations accumulated around B2 precipitates.This study presents an innovative alloy fabrication strategy that enables precise tuning of FCC-BCC dualphase structures,facilitating the direct fabrication of components with spatially customized properties.These findings provide valuable insights for developing multiprincipal element alloys with heterogeneous microstructures for advanced engineering applications.展开更多
Phase imprinting enables the dynamic generation of superflow in bosonic atoms,effectively overcoming traditional limitations such as vortex number constraints and heating effects.However,the mechanisms underlying supe...Phase imprinting enables the dynamic generation of superflow in bosonic atoms,effectively overcoming traditional limitations such as vortex number constraints and heating effects.However,the mechanisms underlying superflow formation remain insufficiently understood.In this work,we reveal these mechanisms by studying the time evolution of the transferred total angular momentum and the quantized current throughout the phase imprinting process,achieved through numerically solving the time-dependent Schrodinger and Gross-Pitaevskii equations.We demonstrate that the Bose gas dynamically acquires angular momentum through the density depletion induced by the phase imprinting potential,whereas quantized currents emerge from azimuthal phase slips accompanied by complete density depletions.Regarding the impact of system parameters,such as interactions,we find that interactions hinder superflow formation,as the azimuthal density distribution becomes less susceptible to the phase imprinting potential.Our findings offer microscopic insights into the dynamic development of superflow during the phase imprinting process and provide valuable guidance for ongoing experimental efforts.展开更多
To explain the precipitation mechanism ofχphase in Co-based superalloys,the microstructural evolution of Co−Ti−Mo superalloys subjected to aging was investigated by X-ray diffraction(XRD),scanning electron microscope...To explain the precipitation mechanism ofχphase in Co-based superalloys,the microstructural evolution of Co−Ti−Mo superalloys subjected to aging was investigated by X-ray diffraction(XRD),scanning electron microscope(SEM)and transmission electron microscope(TEM).The results show that the needle-likeχphase is mainly composed ofD0_(19)-Co_(3)(Ti,Mo),which is transformed from L1_(2-γ′)phase,and a specific orientation relationship exists between them.χphase is nucleated through the shearing ofγ′phase due to the influence of stacking fault.The crystal orientation relationship between L1_(2) andD0_(19)can be confirmed as{111}L1_(2)//{0001}_(D0_(19)),and<112>_(L1_(2))//<1100>_(D0_(19)).The growth ofD0_(19-χ)phase depends on the diffusions of Ti and Mo,and consumes a large number of elements.This progress leads to the appearance ofγ′precipitation depletion zone(PDZ)aroundD0_(19-χ)phase.The addition of Ni improves the stability of L1_(2-γ′)phase and the mechanical properties of Co-based superalloys.展开更多
Quantitative phase imaging(QPI)enables non-invasive cellular analysis by utilizing cell thickness and refractive index as intrinsic probes,revolutionizing label-free microscopy in cellular research.Differential phase ...Quantitative phase imaging(QPI)enables non-invasive cellular analysis by utilizing cell thickness and refractive index as intrinsic probes,revolutionizing label-free microscopy in cellular research.Differential phase contrast(DPC),a non-interferometric QPI technique,requires only four intensity images under asymmetric illumination to recover the phase of a sample,offering the advantages of being label-free,non-coherent and highly robust.Its phase reconstruction result relies on precise modeling of the phase transfer function(PTF).However,in real optical systems,the PTF will deviate from its theoretical ideal due to the unknown wavefront aberrations,which will lead to significant artifacts and distortions in the reconstructed phase.We propose an aberration-corrected DPC(ACDPC)method that utilizes three intensity images under annular illumination to jointly retrieve the aberration and the phase,achieving high-quality QPI with minimal raw data.By employing three annular illuminations precisely matched to the numerical aperture of the objective lens,the object information is transmitted into the acquired intensity with a high signal-to-noise ratio.Phase retrieval is achieved by an iterative deconvolution algorithm that uses simulated annealing to estimate the aberration and further employs regularized deconvolution to reconstruct the phase,ultimately obtaining a refined complex pupil function and an aberration-corrected quantitative phase.We demonstrate that ACDPC is robust to multi-order aberrations without any priori knowledge,and can effectively retrieve and correct system aberrations to obtain high-quality quantitative phase.Experimental results show that ACDPC can clearly reproduce subcellular structures such as vesicles and lipid droplets with higher resolution than conventional DPC,which opens up new possibilities for more accurate subcellular structure analysis in cell biology.展开更多
1.Introduction Phase Ⅱ trials are typically designed to identify promising treatment therapies that warrant further investigation in subsequent phase Ⅲ con-firmatory trials,playing a vital role in evidence generatio...1.Introduction Phase Ⅱ trials are typically designed to identify promising treatment therapies that warrant further investigation in subsequent phase Ⅲ con-firmatory trials,playing a vital role in evidence generation of drug de-velopment.The basic design features of phase II trials include interim go/no-go decisions to prevent exposing too many patients to poten-tially ineffective treatments.Appropriate go/no-go decisions and effi-cient trial designs can shorten the research duration and increase trial success rates.展开更多
This study demonstrates simultaneous enhancement of magnetic and mechanical properties in NdFeB magnets through Ti addition.The coercivity increases by 1.1 kOe without compromising remanence,while bending strength imp...This study demonstrates simultaneous enhancement of magnetic and mechanical properties in NdFeB magnets through Ti addition.The coercivity increases by 1.1 kOe without compromising remanence,while bending strength improves by 159.05%.Analytical results reveal that Ti predominantly combines with free B atoms to form TiB_(2)phases,which reduce the brittleness of grain boundary(GB)phase and impede dislocation motion.The superposition of stress fields around dislocations generates reactive forces that counteract external loads,thereby enhancing GB strength.Concurrently,B depletion in GB phases induces amorphous transformation,further enhancing boundary strength.A minor fraction of Ti incorporates into the main phase,enhancing covalent bond strength and forming a reinforced main phase.Additionally,Ti addition promotes grain refinement and increases GB density,significantly improving bending strength.The synergistic effects of heterogeneous phase formation,amorphous transformation,main phase reinforcement,and grain refinement collectively enable coordinated strengthening between the main phase and GBs.This multi-mechanism approach provides novel insights for mechanical property optimization in Nd FeB magnets.展开更多
In the energy industry landscape,thermal power generation stands as a critical energy supply method,and the safety of its construction and operation is paramount.Currently,all stages of the life cycle of construction ...In the energy industry landscape,thermal power generation stands as a critical energy supply method,and the safety of its construction and operation is paramount.Currently,all stages of the life cycle of construction projects have garnered widespread attention.Among these,the infrastructure construction and operation phases of thermal power generation enterprises pose numerous issues worthy of in-depth study in terms of safety production management.This article starts by examining safety production management during these two phases,analyzing characteristics such as management models,legal bases,and responsible entities.It explores the reasons behind these characteristics and elaborates on key management priorities,providing a comprehensive and insightful reference for safety production management in thermal power generation enterprises.展开更多
Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the p...Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the phase formation mechanism has become the key bottleneck to the practical applications for Cr_(2)AlC synthesis with high purity at low temperatures.In this work,we fabricated the amorphous Cr-Al-C coating by a hybrid magnetron sputtering/cathodic arc deposition technique,in which the in-situ heating transmission electron microscopy(TEM)was conducted in a temperature range of 25-650℃ to address the real-time phase transformation for Cr_(2)AlC coating.The results demonstrated that increas-ing the temperature from 25 to 370℃ led to the structural transformation from amorphous Cr-Al-C to the crystalline Cr_(2)Al interphases.However,the high-purity Cr_(2)AlC MAX phase was distinctly formed at 500℃,accompanied by the diminished amorphous feature.With the further increase of temperature to 650℃,the decomposition of Cr_(2)AlC to Cr_(7)C_(3)impurities was observed.Similar phase evolution was also evidenced by the Ab-initio molecular dynamics calculations,where the bond energy of Cr-Cr,Cr-Al,and Cr-C played the key role in the formed crystalline stability during the heating process.The observa-tions not only provide fundamental insight into the phase formation mechanism for high-purity Cr_(2)AlC coatings but also offer a promising strategy to manipulate the advanced MAX phase materials with high tolerance to high-temperature oxidation and heavy ion radiations.展开更多
基金supported by the National Natural Science Foundation of China(U1507111).
文摘The phase equilibria relationship of the system RbCl-PEG6000-H2O were investigated at temperatures of 288.2,298.2,and 308.2 K,the compositions of solid-liquid equilibria(SLE)and liquid-liquid equilibria(LLE)were determined.The complete phase diagrams,binodal curve diagrams,and tie-line diagrams were all plotted.Results show that both solid-liquid equilibria and liquid-liquid equilibria relationships at each studied temperature.The complete phase diagrams at 288.2 K,298.2 K and 308.2 K consist of six phase regions:unsaturated liquid region(L),two saturated solutions with one solid phase of RbCl(L_S),one saturated liquid phase with two solid phases of PEG6000 and RbCl(2S+L),an aqueous two-phase region(2L),and a region with two liquids and one solid phase of RbCl(2L_S).With the increase in temperature,the layering ability of the aqueous two-phase system increases,and both regions(2L)and(2L_S)increase.The binodal curves were fitted using the nonlinear equations proposed by Mistry,Hu,and Jayapal.Additionally,the tie-line data were correlated with the Othmer-Tobias,Bancroft,Hand,and Bachman equations.The liquid-liquid equilibria at 288.2 K,298.2 K and 308.2 K were calculated using the NRTL model.The findings confirm that the experimental and calculated values are in close agreement,demonstrating the model’s effectiveness in representing the system’s behavior.
文摘The availability of a tremendous amount of seismic data demands seismological researchers to analyze seismic phases efficiently.Recently,deep learning algorithms exhibit a powerful capability of detecting and picking on P-and S-wave phases.However,it remains a challenge to effeciently process enormous teleseismic phases,which are crucial to probe Earth’s interior structures and their dynamics.In this study,we propose a scheme to detect and pick teleseismic phases,such as seismic phase that reflects off the core-mantle boundary(i.e.,PcP)and that reflects off the inner-core boundary(i.e.,PKiKP),from a seismic dataset in Japan.The scheme consists of three steps:1)latent phase traces are truncated from the whole seismogram with theoretical arrival times;2)latent phases are recognized and evaluated by convolutional neural network(CNN)models;3)arrivals of good or fair phase are picked with another CNN models.The testing detection result on 7386 seismograms shows that the scheme recognizes 92.15%and 94.13%of PcP and PKiKP phases.The testing picking result has a mean absolute error of 0.0742 s and 0.0636 s for the PcP and PKiKP phases,respectively.These seismograms were processed in just 5 min for phase detection and picking,demonstrating the efficiency of the proposed scheme in automatic teleseismic phase analysis.
基金granted by the National Natural Science Foundation of China(No.12047503)Wenzhou Institute,University of Chinese Academy of Sciences(No.WIUCASQD2023009)。
文摘Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopolymers,swimming bacteria,artificial swimmers,and animal herds.In contrast to wet active matter,dry active matter is an active system characterized by the absence of significant hydrodynamic interactions and conserved momentum.In dry active matter,the role of surrounding fluids is providing viscous friction at low Reynolds numbers and can be neglected at high Reynolds numbers.This review offers a comprehensive overview of recent experimental,computational,and theoretical advances in understanding phase transitions and critical phenomena in dry aligning active matter,including polar particles,self-propelled rods,active nematics,and their chiral counterparts.Various ways of determining phase transition points as well as non-equilibrium phenomena,such as collective motion,cluster formation,and creation and annihilation of topological defects are reviewed.
基金supported by the National Natural Science Foundation of China(Grant No.51871086).
文摘A phase-field model integrated with the thermodynamic databases was constructed to investigate the impact of Ni content on the precipitation kinetics and phase transformation of the Cu-rich phase in Fe-Cu-Ni alloy at 773 K.The results demonstrated that the Cu core-Ni shell structures form via the decomposition of Cu-Ni co-clusters,which is consistent with previous experimental results.As the Ni content increases,both the volume fraction and number density of Cu-rich precipitates increase,while their size decreases.With the increase in Ni content,the transformation from a Cu to 9R Cu is accelerated,which is the opposite to the result of increasing Mn content.Magnetic energy can increase the nucleation rate of the Cu-rich phase,but it does not affect the phase transformation driving force required for its crystal structure transformation.
文摘As an advanced device for observing atmospheric winds,the spaceborne Doppler Asymmetric Spatial Heterodyne(DASH)interferometer also encounters challenges associated with phase distortion,par-ticularly in limb sounding scenarios.This paper discusses interferogram modeling and phase distortion cor-rection techniques for spaceborne DASH interferometers.The modeling of phase distortion interferograms with and without Doppler shift for limb observation was conducted,and the effectiveness of the analytical expression was verified through numerical simulation.The simulation results indicate that errors propagate layer by layer while using the onion-peeling inversion algorithm to handle phase-distorted interferograms.In contrast,the phase distortion correction algorithm can achieve effective correction.This phase correction method can be successfully applied to correct phase distortions in the interferograms of the spaceborne DASH interferometer,providing a feasible solution to enhance its measurement accuracy.
基金supported by the National Key Research and Development Program of China(2022YFB3505503)the National Natural Science Foundation of China(52201230)+2 种基金the Key R&D Program of Shandong Province(2022CXGC020307)the China Postdoctoral Science Foundation(2022M71204)the Beijing NOVA Program(Z211100002121092).
文摘The grain boundary diffusion process(GBDP)has proven to be an effective method for enhancing the coercivity of sintered Nd-Fe-B magnets.However,the limited diffusion depth and thicker shell struc-ture have impeded the further development of magnetic properties.Currently,the primary debates re-garding the mechanism of GBDP with Tb revolve around the dissolution-solidification mechanism and the atomic substitution mechanism.To clarify this mechanism,the microstructure evolution of sintered Nd-Fe-B magnets during the heating process of GBDP has been systematically studied by quenching at different tem peratures.In this study,it was found that the formation of TbFe_(2) phase is related to the dis-solution of _(2)Fe_(14)B grains during GBDP with Tb.The theory of mixing heat and phase separation further confirms that the Nd_(2)Fe_(14)B phase dissolves to form a mixed phase of Nd and TbFe_(2),which then solidifies into the(Nd,Tb)_(2)Fe_(14)B phase.Based on the discovery of the TbFe_(2) phase,the dissolution-solidification mechanism is considered the primary mechanism for GBDP.This is supported by the elemental content of the two typical core-shell structures observed.
文摘The field of Neurorestoratology is steadily growing.The developmental phases and current key tasks are presented below:Neurorestoratology development divides into four phases,Preparation,Incubation,Growth,and Maturity.1 The characteristics of the Preparation phase.
基金supported by the National Natural Science Foundation of China(No.22271131)the Department of Science and Technology in Jiangxi Province(No.20225BCJ23029).
文摘Organic ferroelastics with metal free features and intrinsically light weight are highly desirable for future applications in flexible,smart and biocompatible devices.However,organoferroelastics with plastic phase transition have rarely been reported yet.Herein,we discovered ferroelasticity in a pair of organic enantiomers,(1S and/or 1R)-2,10-camphorsultam(S-and R-CPS),which undergoes a high-T_(c)plastic phase transition.Both large entropies change of∼45 J mol^(-1)K^(-1)and evidently ductile deformation process confirm the plastic phase feature.Strip-like ferroelastic domain patterns and bidirectional domain movements have been observed via polarized light microscopy and nanoindentation technique,respectively.This work highlights the discovery of organic ferroelastic combining the features of enantiomers and plastic phase transition,which contributes insights into exploration of organic multifunctional materials.
基金This work is supported in part by National Natural Science Foundation of China(No.62401125)Natural Science Foundation of Sichuan Province(No.2023NSFSC1376)Fundamental Research Funds for the Central Universities(No.ZYGX2024J008)。
文摘In this paper,three magnetrons with each of them having specifically designed multiple coupling ports,which deliver specific power distribution for developing a magnetron array based on efficient phase locking between them,are proposed to produce high powerμs-level pulses.To demonstrate the effectiveness of the magnetron with one and two coupling ports as a unit for efficient phase locking,we designed experimentally the coupling ports delivering~10%(the power distribution ratio)of the output power of the magnetron for coupling with other magnetron units.The effect of one and two coupling ports on the operating capability,including the power distribution ratio,anode current and frequency,is demonstrated by establishing an equivalent experimental model which can characterize an ideal operation of the array.The experimental results show that the power distribution ratio is~9%for the magnetron with one coupling port,and~12.5%(coupling port 1,2)for the magnetron with two coupling ports.This shows good uniformity of the coupling capability of the two coupling ports and provides guidance for optimizing the power distribution ratio of multiport magnetron units,which are critical for efficient phase locking in the proposed array in future and higher power arrays.
基金supported by the National Science and Technology Major Project of China(No.J2019-VI-0011-0125)ND Basic Research Funds of China(No.G2022WD)Shaanxi Province Innovation Capability Support Program(No.2023-CX-TD-47).
文摘TiAl alloys with the(α2+γ)lamellar structure are highly valued for their excellent high-temperature strength and creep resistance.Understanding the formation mechanism of the lamellar structure is crucial for tuning the microstructure and properties.This work investigates the formation of lamellar structure in Ti-48AI-7Nb-2.5V-1Cr alloy,revealing the presence of hcp-based long-period superstructure(hcp-LPS)as a metastable phase during lamellar formation.The identification of hcp-LPS demonstrates that the necessary solute enrichment for the formation ofγlamellae occurs on the hexagonalαmatrix,implying that phase separation ofα→Al-richαlamellae+Al-depletedαlamellae is the first step of lamellar formation.Once phase separation is completed,all subsequent phase transitions occur within the Al-richαlamellae.Additionally,the formation of twin lamellae is further discussed.The formation of the twin lamellae occurs sequentially.Pre-existing lamella promotes the formation of later lamella by inducing so-lute enrichment in its surrounding region,and then the successive slip of Shockley partial dislocations with opposite Burgers vectors ensures special stacking of later lamellae.These findings not only con-tribute to the fundamental understanding of spinodal mechanisms in hexagonal crystals,but also provide novel insights into the formation of twin lamellae.
基金financial support by the National Key Research and Development Program of China(No.2023YFB3809101)the National Natural Science Foundation of China(Nos.52371010 and 52422407)+1 种基金the Science and Technology Committee of Shanghai,China(No.21ZR1423600)the Open Project of State Key Laboratory of Baiyunobo Rare Earth Resources Researches and Comprehensive Utilization,China.
文摘Mg-Zn-Mn alloys have the advantages of low cost,excellent mechanical properties,and high corrosion resistance.To clarify the phase equilibria of Mg-Zn-Mn alloy in the Mg-rich corners,the present work experimentally investigated the phase equilibria in the Mg-rich corner at 300-400°C with equilibrated alloy method using electron probe micro analyzer(EPMA),X-ray diffractometer(XRD),transmission electron microscopy(TEM),and differential scanning calorimeter(DSC).Mn atoms were found to dissolve into MgZn_(2) to form a ternary solid-solution type compound,in which Mn content can be up to 15.1at%at 400°C.Three-phase equilibrium ofα-Mg+MgZn_(2)+α-Mn and liquid+α-Mg+MgZn_(2) were confirmed at 400°C.Subsequently,thermodynamic modeling of the Mg-Zn-Mn system was carried out using the CALPHAD method based on the experimental data of this work and literature data.The calculated invariant reaction Liquid+α-Mn→α-Mg+MgZn_(2) at 430°C shows good agreement with the DSC results.In addition,the results of solidification path calculations explain the microstructure in the ascast and annealed alloys well.The agreement between the calculated results and experimental data proves the self-consistency of the thermodynamic database,which can provide guidance for the compositional design of Mg-Zn-Mn alloys.
文摘The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 925 ℃. Below 925 ℃, the volume fraction of secondary Laves phases increases with the rise of the temperature, and its morphology changes from granular to thin-film;above 925 ℃, the volume fraction of secondary Laves phases shows an opposite trend to temperature, and its morphology changes from thin-film to granular. A detailed explanation through linear density (ρ) is provided that the influence of secondary Laves phases at the grain boundaries (GBs) on notch sensitivity depends on the coupling competition effect of their size, quantity, and morphology. Notably, the granular Laves phases are more beneficial to improving the notch sensitivity of the alloy compared with thin-film Laves phases. Granular secondary Laves phases can promote the formation of γ′ phases depletion zone to improve the ability of GBs to accommodate high strain localization, and effectively inhibit the crack initiation and propagation.
基金financially supported by the following sources:Guangdong Basic and Applied Basic Research Foundation(No.2023B1515120045)Yangjiang City Key Industry Talent Revitalization Plan Project for Alloy Materials and Hardware Scissors(No.RCZX202302)+7 种基金GDAS'Project of Science and Technology Development(Nos.2022GDASZH-2022010108,2022GD ASZH-2022010107 and 2024GD ASZH-2024010102)GDAS'Young Talent Project(No.2024GDASQNRC-0314)Guangzhou Basic and Applied Basic Research Foundation(No.2023A04J1628)the National Key R&D Program of China(No.2022YFB4600700)National Natural Science Foundation of China(No.52371110)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011510)Shenzhen Science and Technology Program(Nos.JCYJ20220530115011026 and JCYJ20230807093410021)Shanxi Province Key R&D Project(No.202302050201011)
文摘A novel approach for fabricating multi-principal element alloys with adjustable phase configurations and mechanical properties was developed using laser-aided additive manufacturing(LAAM),combining FCC-structured(face-centered cubic)CoCrNi and BCC-structured(body-centered cubic)CoCrNiAl0.6TiFe feedstocks.During fabrication,CoCrNi powders and CoCrNiAl0.6TiFe powders were simultaneously fed into the melt pool at individually adjustable rates,allowing for controlled phase transitions.The resulting phase evolution demonstrated a gradual transition from a single FCC structure CoCrNi(A10.6TiFe)x(x=0,0.1,0.2,0.3)to a dual FCCB2 structure CoCrNi(Al0.6TiFe)x(x=0.4,0.5)as the proportion of BCC-structured powders increased.The B2 phase,enriched in Ti and Al due to their larger atomic radii and negative segregation enthalpy,precipitated around the FCC matrix,with volume fractions of 0.5%and 5.7%for CoCrNi(A10.6TiFe)0.4 and CoCrNi(A10.6TiFe)0.5,respectively.This phase transition resulted in significant mechanical enhancements.Yield and ultimate tensile strengths increased from 486.0 and 781.2 MPa(CoCrNi)to 887.2 and 1165.2 MPa(CoCrNi(A10.6TiFe)0.5).Dislocation-mediated hardening prevailed in single-phase FCC alloys,exhibiting a characteristic dislocation density of 2.5×10^(15)m^(-2)for CoCrNi(A10.6TiFe)0.3 alloy.Once the B2 phase precipitated,precipitation strengthening became dominant,as observed in transmission electron microscopy(TEM),where dislocations accumulated around B2 precipitates.This study presents an innovative alloy fabrication strategy that enables precise tuning of FCC-BCC dualphase structures,facilitating the direct fabrication of components with spatially customized properties.These findings provide valuable insights for developing multiprincipal element alloys with heterogeneous microstructures for advanced engineering applications.
基金supported by the National Natural Science Foundation of China(Grants Nos.12104406 and 12204105)the Natural Science Foundation Zhejiang Province,China(Grant No.ZCLMS25A0401)+1 种基金the Startup Grant of Zhejiang SciTech University(Grant No.21062338-Y)the Natural Science Foundation of Fujian Province,China(Grant No.2022J05116)。
文摘Phase imprinting enables the dynamic generation of superflow in bosonic atoms,effectively overcoming traditional limitations such as vortex number constraints and heating effects.However,the mechanisms underlying superflow formation remain insufficiently understood.In this work,we reveal these mechanisms by studying the time evolution of the transferred total angular momentum and the quantized current throughout the phase imprinting process,achieved through numerically solving the time-dependent Schrodinger and Gross-Pitaevskii equations.We demonstrate that the Bose gas dynamically acquires angular momentum through the density depletion induced by the phase imprinting potential,whereas quantized currents emerge from azimuthal phase slips accompanied by complete density depletions.Regarding the impact of system parameters,such as interactions,we find that interactions hinder superflow formation,as the azimuthal density distribution becomes less susceptible to the phase imprinting potential.Our findings offer microscopic insights into the dynamic development of superflow during the phase imprinting process and provide valuable guidance for ongoing experimental efforts.
基金The financial supports from the National Natural Science Foundation of China(Nos.52171107,52201203)the National Natural Science Foundation of China-Joint Fund of Iron and Steel Research(No.U1960204)the“333”Talent Project of Hebei Province,China(No.B20221001)are gratefully acknowledged.
文摘To explain the precipitation mechanism ofχphase in Co-based superalloys,the microstructural evolution of Co−Ti−Mo superalloys subjected to aging was investigated by X-ray diffraction(XRD),scanning electron microscope(SEM)and transmission electron microscope(TEM).The results show that the needle-likeχphase is mainly composed ofD0_(19)-Co_(3)(Ti,Mo),which is transformed from L1_(2-γ′)phase,and a specific orientation relationship exists between them.χphase is nucleated through the shearing ofγ′phase due to the influence of stacking fault.The crystal orientation relationship between L1_(2) andD0_(19)can be confirmed as{111}L1_(2)//{0001}_(D0_(19)),and<112>_(L1_(2))//<1100>_(D0_(19)).The growth ofD0_(19-χ)phase depends on the diffusions of Ti and Mo,and consumes a large number of elements.This progress leads to the appearance ofγ′precipitation depletion zone(PDZ)aroundD0_(19-χ)phase.The addition of Ni improves the stability of L1_(2-γ′)phase and the mechanical properties of Co-based superalloys.
基金supported by the National Natural Science Foundation of China(62305162,62227818,62361136588)China Postdoctoral Science Foundation(2023TQ0160,2023M731683)+5 种基金Nanjing University of Science and Technology independent research project(30923010305)National Key Research and Development Program of China(2024YFE0101300)Biomedical Competition Foundation of Jiangsu Province(BE2022847)Key National Industrial Technology Cooperation Foundation of Jiangsu Province(BZ2022039)Fundamental Research Funds for the Central Universities(2023102001)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense(JSGP202105,JSGP202201,JSGPCXZNGZ202401)。
文摘Quantitative phase imaging(QPI)enables non-invasive cellular analysis by utilizing cell thickness and refractive index as intrinsic probes,revolutionizing label-free microscopy in cellular research.Differential phase contrast(DPC),a non-interferometric QPI technique,requires only four intensity images under asymmetric illumination to recover the phase of a sample,offering the advantages of being label-free,non-coherent and highly robust.Its phase reconstruction result relies on precise modeling of the phase transfer function(PTF).However,in real optical systems,the PTF will deviate from its theoretical ideal due to the unknown wavefront aberrations,which will lead to significant artifacts and distortions in the reconstructed phase.We propose an aberration-corrected DPC(ACDPC)method that utilizes three intensity images under annular illumination to jointly retrieve the aberration and the phase,achieving high-quality QPI with minimal raw data.By employing three annular illuminations precisely matched to the numerical aperture of the objective lens,the object information is transmitted into the acquired intensity with a high signal-to-noise ratio.Phase retrieval is achieved by an iterative deconvolution algorithm that uses simulated annealing to estimate the aberration and further employs regularized deconvolution to reconstruct the phase,ultimately obtaining a refined complex pupil function and an aberration-corrected quantitative phase.We demonstrate that ACDPC is robust to multi-order aberrations without any priori knowledge,and can effectively retrieve and correct system aberrations to obtain high-quality quantitative phase.Experimental results show that ACDPC can clearly reproduce subcellular structures such as vesicles and lipid droplets with higher resolution than conventional DPC,which opens up new possibilities for more accurate subcellular structure analysis in cell biology.
基金funded by Beijing Nova Program(grant number:20230484277)National Natural Science Foundation of China(grant number:82303955).
文摘1.Introduction Phase Ⅱ trials are typically designed to identify promising treatment therapies that warrant further investigation in subsequent phase Ⅲ con-firmatory trials,playing a vital role in evidence generation of drug de-velopment.The basic design features of phase II trials include interim go/no-go decisions to prevent exposing too many patients to poten-tially ineffective treatments.Appropriate go/no-go decisions and effi-cient trial designs can shorten the research duration and increase trial success rates.
基金financially supported by the National Natural Science Foundation of China(No.52361033)National Key Research and Development Program(No.2022YFB3505400)+6 种基金Ministry of Industry and Information Technology Heavy Rare Earth Special use of Sintered NdFeB Project(No.TC220H06J)Academic and Technical Leaders in Major Disciplines in Jiangxi Province(No.20225BCJ23007)Jiangxi Natural Science Foundation Youth Fund(No.20232BAB214011)the Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)Research Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(No.E255J001)Science and Technology Major Project of Ganzhou(No.202101064871)Program for Excellent Young Talents(No.JXUSTQJYC2024003)
文摘This study demonstrates simultaneous enhancement of magnetic and mechanical properties in NdFeB magnets through Ti addition.The coercivity increases by 1.1 kOe without compromising remanence,while bending strength improves by 159.05%.Analytical results reveal that Ti predominantly combines with free B atoms to form TiB_(2)phases,which reduce the brittleness of grain boundary(GB)phase and impede dislocation motion.The superposition of stress fields around dislocations generates reactive forces that counteract external loads,thereby enhancing GB strength.Concurrently,B depletion in GB phases induces amorphous transformation,further enhancing boundary strength.A minor fraction of Ti incorporates into the main phase,enhancing covalent bond strength and forming a reinforced main phase.Additionally,Ti addition promotes grain refinement and increases GB density,significantly improving bending strength.The synergistic effects of heterogeneous phase formation,amorphous transformation,main phase reinforcement,and grain refinement collectively enable coordinated strengthening between the main phase and GBs.This multi-mechanism approach provides novel insights for mechanical property optimization in Nd FeB magnets.
文摘In the energy industry landscape,thermal power generation stands as a critical energy supply method,and the safety of its construction and operation is paramount.Currently,all stages of the life cycle of construction projects have garnered widespread attention.Among these,the infrastructure construction and operation phases of thermal power generation enterprises pose numerous issues worthy of in-depth study in terms of safety production management.This article starts by examining safety production management during these two phases,analyzing characteristics such as management models,legal bases,and responsible entities.It explores the reasons behind these characteristics and elaborates on key management priorities,providing a comprehensive and insightful reference for safety production management in thermal power generation enterprises.
基金supported by the financial support of the National Science Fund for Distinguished Young Scholars of China(No.52025014)the National Natural Science Foundation of China(Nos.52101109 and 52171090)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LD24E010003 and LZJWY23E090001)the Natural Science Foundation of Ningbo(Nos.2023J410).
文摘Cr_(2)AlC,a representative MAX phase,gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments.However,the lack of the phase formation mechanism has become the key bottleneck to the practical applications for Cr_(2)AlC synthesis with high purity at low temperatures.In this work,we fabricated the amorphous Cr-Al-C coating by a hybrid magnetron sputtering/cathodic arc deposition technique,in which the in-situ heating transmission electron microscopy(TEM)was conducted in a temperature range of 25-650℃ to address the real-time phase transformation for Cr_(2)AlC coating.The results demonstrated that increas-ing the temperature from 25 to 370℃ led to the structural transformation from amorphous Cr-Al-C to the crystalline Cr_(2)Al interphases.However,the high-purity Cr_(2)AlC MAX phase was distinctly formed at 500℃,accompanied by the diminished amorphous feature.With the further increase of temperature to 650℃,the decomposition of Cr_(2)AlC to Cr_(7)C_(3)impurities was observed.Similar phase evolution was also evidenced by the Ab-initio molecular dynamics calculations,where the bond energy of Cr-Cr,Cr-Al,and Cr-C played the key role in the formed crystalline stability during the heating process.The observa-tions not only provide fundamental insight into the phase formation mechanism for high-purity Cr_(2)AlC coatings but also offer a promising strategy to manipulate the advanced MAX phase materials with high tolerance to high-temperature oxidation and heavy ion radiations.
