Halide perovskites have attracted great interest as active layers in optoelectronic devices. Among perovskites with diverse compositions, α-FAPbI_(3) is of utmost importance with great optoelectronic properties and a...Halide perovskites have attracted great interest as active layers in optoelectronic devices. Among perovskites with diverse compositions, α-FAPbI_(3) is of utmost importance with great optoelectronic properties and a decent bandgap of 1.48 eV.However, the α-phase suffers an irreversible transition to the photo-inactive δ-phase, whereas the δ-phase is usually regarded as useless phase with poor optoelectronic properties. Therefore, it is commonly accepted that the thermodynamic stable δ-FAPbI_(3) greatly limits the application of FAPbI_(3). Every coin has two sides, although the δ-phase is difficult to apply as photoelectrical active layers, it is possible to combine δ-FAPbI_(3) with α-FAPbI_(3) to realize functional applications. Firstly, this review analyzes the cause of the contrasting properties between α-and δ-FAPbI_(3), where the stronger electron-phonon coupling in 1D hexagonal δ-FAPbI_(3) restricts its internal carrier and phonon transport. Secondly, the factors affecting the phase transitions and strategies to control phase transition between α-and δ-FAPbI_(3) are presented. Finally, some functional applications of δ-FAPbI_(3) in combination with α-FAPbI_(3) are given according to previous reports. By and large, we hope to introduce δ-FAPbI_(3) from another perspective and give some insights into its unique properties, hopefully providing new strategies for the subsequent advances to FAPbI_(3).展开更多
Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+d...Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.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 longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of...A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of heavy transition metal mononitrides.Here,we systematically investigate the structural evolutionof LaN under high pressure using first-principles calculations combined with angle-dispersive synchrotron X-raydiffraction,identifying the phase transition sequence and corresponding phase boundaries.Analyses of energetics,kinetic barriers,and lattice dynamics reveal distinct mechanisms driving these transitions.These results clarifythe structural stability of LaN and offer guidance for studying other heavy transition metal mononitrides withcomplex electronic behavior under extreme conditions.展开更多
Multiple switchable physical channels within one material or device,encompassing optical,electrical,thermal,and mechanical pathways,can enable multifunctionality in mechanical-thermal-opto-electronic applications.Achi...Multiple switchable physical channels within one material or device,encompassing optical,electrical,thermal,and mechanical pathways,can enable multifunctionality in mechanical-thermal-opto-electronic applications.Achieving integrated encryption and enhanced performance in storage and sensing presents a formidable challenge in the synthesis and functionality of new materials.In an effort to overcome the complexities associated with these multiple physical functions,this study investigates the large-size crystal of DPACdCl_(4)(DPA=diisopropylammonium),revealing significant features in rare multi-channel switches.This compound demonstrates the ability to switch between"OFF/0"and"ON/1"states in the mechanical-thermal-opto-electronic channels.Consequently,DPACd Cl_(4)possesses four switchable physical channels,characterized by a higher phase transition temperature of 440.7 K and a competitive piezo-electric coefficient of 46 pC/N.Furthermore,solid-state NMR analysis indicates that thermally activated molecular vibrations significantly contribute to its multifunctional switching capabilities.展开更多
The phase transition among different solid forms of active pharmaceutical ingredients can significantly influence their physicochemical properties,potentially leading to clinical safety risks.However,phase transition ...The phase transition among different solid forms of active pharmaceutical ingredients can significantly influence their physicochemical properties,potentially leading to clinical safety risks.However,phase transition mechanisms remain under explored,especially in multi-component drugs.Here we report a novel ciprofloxacin-diclofenac salt system and investigate phase transitions among its anhydrate,dihydrate,and methanol solvate forms.The study focused on the influence of water activity and solvent vapor conditions,elucidating the role of vip molecules in driving these transitions.These findings offer new insights into polymorphic phase transitions,advancing our understanding of stability and performance in pharmaceutical formulations.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
It is a key challenge to prepare two-dimensional diamond(2D-diamond).Herein,we develop a method for synthesizing 2D-diamond by depositing monodisperse tantalum(Ta)atoms onto graphene substrates using a hot-filament ch...It is a key challenge to prepare two-dimensional diamond(2D-diamond).Herein,we develop a method for synthesizing 2D-diamond by depositing monodisperse tantalum(Ta)atoms onto graphene substrates using a hot-filament chemical vapor deposition setup,followed by annealing treatment under different temperatures at ambient pressure.The results indicate that when the annealing temperature increases from 700℃ to 1000℃,the size of the 2D-diamond found in the samples gradually increases from close to 20 nm to around 30 nm.Meanwhile,the size and number of amorphous carbon spheres and Ta-containing compounds between the graphene layers gradually increase.As the annealing temperature continues to rise to 1100℃,a significant aggregation of Ta-containing compounds is observed in the samples,with no diamond structure detected.This further confirms that monodisperse Ta atoms play a key role in graphene phase transition into 2D-diamond.This study provides a novel method for the ambient-pressure phase transition of graphene into 2D-diamond.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 deployment of non-precious metal catalysts for the production of COx-free hydrogen via the ammonia decomposition reaction(ADR)presents a promising yet great challenge.In the present study,two crystal structures of...The deployment of non-precious metal catalysts for the production of COx-free hydrogen via the ammonia decomposition reaction(ADR)presents a promising yet great challenge.In the present study,two crystal structures of α-MoC and β-Mo_(2)C catalysts with different Mo/C ratios were synthesized,and their ammonia decomposition performance as well as structural evolution in ADR was investigated.The β-Mo_(2)C catalyst,characterized by a higher Mo/C ratio,demonstrated a remarkable turnover frequency of 1.3 s^(-1),which is over tenfold higher than that ofα-MoC(0.1 s^(-1)).An increase in the Mo/C ratio of molybdenum carbide revealed a direct correlation between the surface Mo/C ratio and the hydrogen yield.The transient response surface reaction indicated that the combination of N*and N*derived from NH_(3) dissociation represents the rate-determining step in the ADR,andβ-Mo2C exhibited exceptional proficiency in facilitating this pivotal step.Concurrently,the accumulation of N*species on the carbide surface could induce the phase transition of molybdenum carbide to nitride,which follows a topological transformation.It is discovered that such phase evolution was affected by the Mo-C surface and reaction temperature simultaneously.When the kinetics of combination of N*was accelerated by rising temperatures and its accumulation on the carbide surface was mitigated,β-Mo_(2)C maintained its carbide phase,preventing nitridation during the ADR at 810℃.Our results contribute to an in-depth understanding of the molybdenum carbides’catalytic properties in ADR and highlight the nature of the carbide-nitride phase transition in the reaction.展开更多
It has been argued that the human brain,as an information-processing machine,operates near a phase transition point in a non-equilibrium state,where it violates detailed balance leading to entropy production.Thus,the ...It has been argued that the human brain,as an information-processing machine,operates near a phase transition point in a non-equilibrium state,where it violates detailed balance leading to entropy production.Thus,the assessment of irreversibility in brain networks can provide valuable insights into their non-equilibrium properties.In this study,we utilized an open-source whole-brain functional magnetic resonance imaging(fMRI)dataset from both resting and task states to evaluate the irreversibility of large-scale human brain networks.Our analysis revealed that the brain networks exhibited significant irreversibility,violating detailed balance,and generating entropy.Notably,both physical and cognitive tasks increased the extent of this violation compared to the resting state.Regardless of the state(rest or task),interactions between pairs of brain regions were the primary contributors to this irreversibility.Moreover,we observed that as global synchrony increased within brain networks,so did irreversibility.The first derivative of irreversibility with respect to synchronization peaked near the phase transition point,characterized by the moderate mean synchronization and maximized synchronization entropy of blood oxygenation level-dependent(BOLD)signals.These findings deepen our understanding of the non-equilibrium dynamics of large-scale brain networks,particularly in relation to their phase transition behaviors,and may have potential clinical applications for brain disorders.展开更多
The slow phase transition from formⅡto formⅠhas always been an important factor that restricts the processing and application of polybutene-1(PB-1).After extensive efforts,a set of effective methods for promoting th...The slow phase transition from formⅡto formⅠhas always been an important factor that restricts the processing and application of polybutene-1(PB-1).After extensive efforts,a set of effective methods for promoting the phase transition rate in PB-1 was established by adjusting the crystallization,nucleation,and growth temperatures.Nevertheless,low-molecular-weight PB-1(LMWPB-1)faces challenges because this method requires a low crystallization temperature,which is difficult to achieve during extrusion processing.In this study,we attempted to increase the phase transition rate in PB-1 by changing the annealing temperature after processing rather than the crystallization temperature in the classical scheme.The results indicated that regardless of low-or high-molecular-weight PB-1,repeated annealing between 0 and 90℃could also promote formⅡto formⅠphase transition.The initial content of formⅠincreased with the heating and cooling cycles.The half-time of the phase transition(t_(1/2))was also shortened after heating/cooling.After 100 heating/cooling cycles,t_(1/2) was reduced to one-quarter of that without annealing,which had almost the same effect as the crystallization temperature at 25℃in promoting the phase transition.This study indicates that annealing after processing is also an important factor affecting the phase transition of PB-1,and should receive sufficient attention.展开更多
Figure 6(a)in the paper[Chin.Phys.B 33074203(2024)]was incorrect due to editorial oversight.The correct figure is provided.This modification does not affect the result presented in the paper.
Thermoelectric coolers utilizing the Peltier effect have dominated the field of solid-state cooling but their efficiency is hindered by material limitations.Alternative routes based on the Thomson and Nernst effects o...Thermoelectric coolers utilizing the Peltier effect have dominated the field of solid-state cooling but their efficiency is hindered by material limitations.Alternative routes based on the Thomson and Nernst effects offer new possibilities.Here,we present a comprehensive investigation of the thermoelectric properties of 1T-TiSe_(2),focusing on these effects around the charge density wave transition(≈200 K).The abrupt Fermi surface reconstruction associated with this transition leads to an exceptional peak in the Thomson coefficient of 450μVK^(-1) at 184 K,surpassing the Seebeck coefficient.Furthermore,1T-TiSe_(2) exhibits a remarkably broad temperature range(170-400 K)with a Thomson coefficient exceeding 190μV K^(-1),a characteristic highly desirable for the development of practical Thomson coolers with extended operational ranges.Additionally,the Nernst coefficient exhibits an unusual temperature dependence,increasing with temperature in the normal phase,which we attribute to bipolar conduction effects.The combination of solid-solid pure electronic phase transition to a semimetallic phase with bipolar transport is identified as responsible for the unusual Nernst trend and the unusually large Thomson coefficient over a broad temperature range.展开更多
The stretching-induced phase transition of biodegradable poly(butylene succinate)(PBS)was explored using a combination of mechanical testing and in situ wide angle X-ray diffraction characterization.The phase transiti...The stretching-induced phase transition of biodegradable poly(butylene succinate)(PBS)was explored using a combination of mechanical testing and in situ wide angle X-ray diffraction characterization.The phase transition fromαphase toβphase can be effectively triggered by severe stretching,in which the threshold strain is dependent on the PBS crystallites.Interestingly,thisα-βphase transition can be reversed immediately once mechanical stretching begins to be released.It should be pointed out that the finish ofβ-αphase transition reversed,corresponding to the disappearance of the generatedβphase,does not necessarily need the external stretching to completely release.For the relaxation-reversed phase transition,the evolution of the normalizedβ-phase fraction exhibited a similar correlation with the stress released.It was indicated that the decay kinetics followed a stretching-dominant mechanism,and the amount ofβphase generated just prior to relaxation had a negligible influence on the reversed phase transition.展开更多
Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effec...Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effective Hamiltonian method in conjuction with the phase-field model, we have successfully reproduced the thermal hysteresis observed in ferroelectric materials during phase transitions. The computational results regarding the electrocaloric effect from these two different computational scales closely align with experimental measurements. Furthermore, we analyze how the first-order ferroelectric phase transition gradually diminishes with an increasing applied electric field, exhibiting characteristics of second-order-like phase transition. By employing the characteristic parameters of thermal hysteresis, we have established a pathway for calculations across different computational scales, thereby providing theoretical support for further investigations into the properties of ferroelectric materials through concurrent multiscale simulations.展开更多
Laves-phase are among the most abundant groups of alloys with chemical formula AB_(2),known for their hightemperature strength and potential application in hydrogen storage.The Laves-phase generally acts as a strength...Laves-phase are among the most abundant groups of alloys with chemical formula AB_(2),known for their hightemperature strength and potential application in hydrogen storage.The Laves-phase generally acts as a strengthening agent,which enhances the strength and durability of alloys at extreme conditions.Consequently,the properties of Lavesphase alloys at extreme conditions attract wide attention.In this study,we investigated the high-pressure phase diagram of Laves-phase alloy HfZn_(2),and discovered a phase transition from C15(space group Fd3m)phase to C14(space group P63/mmc)phase at a pressure above 20 GPa.Based on ab initio simulations,the mechanical,chemical bonding and superconducting properties of high-pressure phase HfZn_(2)were predicted.The ratio of bulk modulus to shear modulus(B/G),a key indicator of mechanical properties in alloys,increases from 1.86 to 4.09 within the pressure range of 50-250 GPa,indicating excellent ductility of the C14 phase of HfZn_(2)under high pressure.Additionally,Zn gains approximately 0.43 electron from Hf at 10 GPa,and the superconducting critical temperature of HfZn_(2)is estimated to be around 0.55 K at 50 GPa.Given that both C14 and C15 phases are common structures in Laves-phase alloys,elucidating the high-pressure behaviors of C14 and C15 phases of HfZn_(2)will enhance the fundamental understanding of properties and potential applications at extreme conditions of Laves-phase alloys.展开更多
P2-type layered oxide cathode materials have attracted extensive attention due to their simple preparation,high specific capacity,adjustable voltage range,and high packing density.However,the harmful phase transitions...P2-type layered oxide cathode materials have attracted extensive attention due to their simple preparation,high specific capacity,adjustable voltage range,and high packing density.However,the harmful phase transitions that occur at high voltage severely limit their practical application.Herein,a novel high-valence tungsten doped P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)cathode material was prepared using the sol–gel method.Through diffusion kinetics analysis and in situ X-ray diffraction(in situ XRD),it has been proven that W^(6+)not only enhances the Na^(+)diffusion coefficient but also reduces the P2–O2 phase transition.The optimized NNMO-W1%delivers a high discharge specific capacity of 163 mAh·g^(-1)at 0.1C,and the capacity retention rate is as high as 77.6%after 1000 cycles at 10C.This is mainly due to that W^(6+)enters the lattice,optimizing the arrangement of primary particles.This work sheds light on the design and construction of high-performance layered oxides cathode materials.展开更多
We investigate the localization and topological properties of the Haldane model under the influence of random flux and Anderson disorder. Our localization analysis reveals that random flux induces a transition from in...We investigate the localization and topological properties of the Haldane model under the influence of random flux and Anderson disorder. Our localization analysis reveals that random flux induces a transition from insulating to metallic states, while Anderson localization only arises under the modulation of Anderson disorder. By employing real-space topological invariant methods, we demonstrates that the system undergoes topological phase transitions under different disorder manipulations, whereas random flux modulation uniquely induces topological Anderson insulator phases, with the potential to generate states with opposite Chern numbers. These findings highlight the distinct roles of disorder in shaping the interplay between topology and localization, providing insights into stabilizing topological states and designing robust topological quantum materials.展开更多
We investigate the boundary effect of quark–gluon plasma(QGP)droplets and the self-similarity effect of hadrons on QGP–hadron phase transition.In intermediate-or low-energy collisions,when the transverse momentum is...We investigate the boundary effect of quark–gluon plasma(QGP)droplets and the self-similarity effect of hadrons on QGP–hadron phase transition.In intermediate-or low-energy collisions,when the transverse momentum is below quantum chromodynamics(QCD)scale,QGP cannot be produced.However,if the transverse momentum changes to a relatively large value,a smallscale QGP droplet is produced.The modified MIT bag model with the multiple reflection expansion method is employed to study the QGP droplet with the curved boundary effect.It is found that the energy density,entropy density and pressure of QGP with the influence are smaller than those without the influence.In the hadron phase,we propose the two-body fractal model(TBFM)to study the self-similarity structure,arising from resonance,quantum correlation and interaction effects.It is observed that the energy density,entropy density and pressure increase due to the self-similarity structure.We calculate the transverse momentum spectra of pions with the self-similarity structure influence,which show good agreement with experimental data.Considering both boundary effect and self-similarity structure influence,our model predicts an increase in the transition temperature compared to the scenarios without these two effects in the High Intensity heavy-ion Accelerator Facility(HIAF)energy region,2.2 GeV to approximately 4.5 GeV.展开更多
基金supported by the National Natural Science Foundation of China (Nos. T2322003, 52172146)the Fundamental Research Funds for the Central Universities (No. 2242024K40017)Shuangchuang Talent of Jiangsu Province (No. JSSCRC2021506)。
文摘Halide perovskites have attracted great interest as active layers in optoelectronic devices. Among perovskites with diverse compositions, α-FAPbI_(3) is of utmost importance with great optoelectronic properties and a decent bandgap of 1.48 eV.However, the α-phase suffers an irreversible transition to the photo-inactive δ-phase, whereas the δ-phase is usually regarded as useless phase with poor optoelectronic properties. Therefore, it is commonly accepted that the thermodynamic stable δ-FAPbI_(3) greatly limits the application of FAPbI_(3). Every coin has two sides, although the δ-phase is difficult to apply as photoelectrical active layers, it is possible to combine δ-FAPbI_(3) with α-FAPbI_(3) to realize functional applications. Firstly, this review analyzes the cause of the contrasting properties between α-and δ-FAPbI_(3), where the stronger electron-phonon coupling in 1D hexagonal δ-FAPbI_(3) restricts its internal carrier and phonon transport. Secondly, the factors affecting the phase transitions and strategies to control phase transition between α-and δ-FAPbI_(3) are presented. Finally, some functional applications of δ-FAPbI_(3) in combination with α-FAPbI_(3) are given according to previous reports. By and large, we hope to introduce δ-FAPbI_(3) from another perspective and give some insights into its unique properties, hopefully providing new strategies for the subsequent advances to FAPbI_(3).
基金supported by the National Natural Science Foundation of China(No.21805018)by Sichuan Science and Technology Program(Nos.2022ZHCG0018,2023NSFSC0117 and 2023ZHCG0060)Yibin Science and Technology Program(No.2022JB005)and China Postdoctoral Science Foundation(No.2022M722704).
文摘Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.
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 Natural Science Foundation of China(Grant Nos.T2325013,12474004,and 52288102)the National Key Research and Development Program of China(Grant No.2021YFA1400503)the Program for Jilin University Science and Technology Innovative Research Team。
文摘A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of heavy transition metal mononitrides.Here,we systematically investigate the structural evolutionof LaN under high pressure using first-principles calculations combined with angle-dispersive synchrotron X-raydiffraction,identifying the phase transition sequence and corresponding phase boundaries.Analyses of energetics,kinetic barriers,and lattice dynamics reveal distinct mechanisms driving these transitions.These results clarifythe structural stability of LaN and offer guidance for studying other heavy transition metal mononitrides withcomplex electronic behavior under extreme conditions.
基金financial supported by National Natural Science Foundation of China(No.52303256)Natural Science Foundation of Zhejiang Province(No.LQ23B040004)Jinhua Industrial Major Project(No.2022-1-043)。
文摘Multiple switchable physical channels within one material or device,encompassing optical,electrical,thermal,and mechanical pathways,can enable multifunctionality in mechanical-thermal-opto-electronic applications.Achieving integrated encryption and enhanced performance in storage and sensing presents a formidable challenge in the synthesis and functionality of new materials.In an effort to overcome the complexities associated with these multiple physical functions,this study investigates the large-size crystal of DPACdCl_(4)(DPA=diisopropylammonium),revealing significant features in rare multi-channel switches.This compound demonstrates the ability to switch between"OFF/0"and"ON/1"states in the mechanical-thermal-opto-electronic channels.Consequently,DPACd Cl_(4)possesses four switchable physical channels,characterized by a higher phase transition temperature of 440.7 K and a competitive piezo-electric coefficient of 46 pC/N.Furthermore,solid-state NMR analysis indicates that thermally activated molecular vibrations significantly contribute to its multifunctional switching capabilities.
基金supported by the Young Scientists Promotion Fund of Natural Science Foundation of Guangdong Province(No.2023A1515030128)Natural Science Foundation of Guangdong Province(No.2024A1515011590)+1 种基金National Natural Science Foundation of China(No.81703438)CAMS Innovation Fund for Medical Sciences(No.2022-I2M-1-015).
文摘The phase transition among different solid forms of active pharmaceutical ingredients can significantly influence their physicochemical properties,potentially leading to clinical safety risks.However,phase transition mechanisms remain under explored,especially in multi-component drugs.Here we report a novel ciprofloxacin-diclofenac salt system and investigate phase transitions among its anhydrate,dihydrate,and methanol solvate forms.The study focused on the influence of water activity and solvent vapor conditions,elucidating the role of vip molecules in driving these transitions.These findings offer new insights into polymorphic phase transitions,advancing our understanding of stability and performance in pharmaceutical formulations.
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supported by the Key Project of the National Natural Science Foundation of China(Grant No.U1809210)the International Science Technology Cooperation Program of China(Grant No.2014DFR51160)+3 种基金the One Belt and One Road International Cooperation Project from the Key Research and Development Program of Zhejiang Province,China(Grant No.2018C04021)the National Natural Science Foundation of China(Grant Nos.50972129,50602039,and 52102052)the Fund from Institute of Wenzhou,Zhejiang University(Grant Nos.XMGL-CX-202305 and XMGLKJZX-202307)the Project from Tanghe Scientific&Technology Company(Grant No.KYY-HX-20230024).
文摘It is a key challenge to prepare two-dimensional diamond(2D-diamond).Herein,we develop a method for synthesizing 2D-diamond by depositing monodisperse tantalum(Ta)atoms onto graphene substrates using a hot-filament chemical vapor deposition setup,followed by annealing treatment under different temperatures at ambient pressure.The results indicate that when the annealing temperature increases from 700℃ to 1000℃,the size of the 2D-diamond found in the samples gradually increases from close to 20 nm to around 30 nm.Meanwhile,the size and number of amorphous carbon spheres and Ta-containing compounds between the graphene layers gradually increase.As the annealing temperature continues to rise to 1100℃,a significant aggregation of Ta-containing compounds is observed in the samples,with no diamond structure detected.This further confirms that monodisperse Ta atoms play a key role in graphene phase transition into 2D-diamond.This study provides a novel method for the ambient-pressure phase transition of graphene into 2D-diamond.
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 deployment of non-precious metal catalysts for the production of COx-free hydrogen via the ammonia decomposition reaction(ADR)presents a promising yet great challenge.In the present study,two crystal structures of α-MoC and β-Mo_(2)C catalysts with different Mo/C ratios were synthesized,and their ammonia decomposition performance as well as structural evolution in ADR was investigated.The β-Mo_(2)C catalyst,characterized by a higher Mo/C ratio,demonstrated a remarkable turnover frequency of 1.3 s^(-1),which is over tenfold higher than that ofα-MoC(0.1 s^(-1)).An increase in the Mo/C ratio of molybdenum carbide revealed a direct correlation between the surface Mo/C ratio and the hydrogen yield.The transient response surface reaction indicated that the combination of N*and N*derived from NH_(3) dissociation represents the rate-determining step in the ADR,andβ-Mo2C exhibited exceptional proficiency in facilitating this pivotal step.Concurrently,the accumulation of N*species on the carbide surface could induce the phase transition of molybdenum carbide to nitride,which follows a topological transformation.It is discovered that such phase evolution was affected by the Mo-C surface and reaction temperature simultaneously.When the kinetics of combination of N*was accelerated by rising temperatures and its accumulation on the carbide surface was mitigated,β-Mo_(2)C maintained its carbide phase,preventing nitridation during the ADR at 810℃.Our results contribute to an in-depth understanding of the molybdenum carbides’catalytic properties in ADR and highlight the nature of the carbide-nitride phase transition in the reaction.
基金supported by the Fundamental Research Funds for the Central Universities(Grant Nos.lzujbky-2021-62 and lzujbky-2024-jdzx06)the National Natural Science Foundation of China(Grant No.12247101)+1 种基金the Natural Science Foundation of Gansu Province,China(Grant Nos.22JR5RA389 and 23JRRA1740)the‘111 Center’Fund(Grant No.B20063).
文摘It has been argued that the human brain,as an information-processing machine,operates near a phase transition point in a non-equilibrium state,where it violates detailed balance leading to entropy production.Thus,the assessment of irreversibility in brain networks can provide valuable insights into their non-equilibrium properties.In this study,we utilized an open-source whole-brain functional magnetic resonance imaging(fMRI)dataset from both resting and task states to evaluate the irreversibility of large-scale human brain networks.Our analysis revealed that the brain networks exhibited significant irreversibility,violating detailed balance,and generating entropy.Notably,both physical and cognitive tasks increased the extent of this violation compared to the resting state.Regardless of the state(rest or task),interactions between pairs of brain regions were the primary contributors to this irreversibility.Moreover,we observed that as global synchrony increased within brain networks,so did irreversibility.The first derivative of irreversibility with respect to synchronization peaked near the phase transition point,characterized by the moderate mean synchronization and maximized synchronization entropy of blood oxygenation level-dependent(BOLD)signals.These findings deepen our understanding of the non-equilibrium dynamics of large-scale brain networks,particularly in relation to their phase transition behaviors,and may have potential clinical applications for brain disorders.
基金financially supported by the National Natural Science Foundation of China(No.22175183)。
文摘The slow phase transition from formⅡto formⅠhas always been an important factor that restricts the processing and application of polybutene-1(PB-1).After extensive efforts,a set of effective methods for promoting the phase transition rate in PB-1 was established by adjusting the crystallization,nucleation,and growth temperatures.Nevertheless,low-molecular-weight PB-1(LMWPB-1)faces challenges because this method requires a low crystallization temperature,which is difficult to achieve during extrusion processing.In this study,we attempted to increase the phase transition rate in PB-1 by changing the annealing temperature after processing rather than the crystallization temperature in the classical scheme.The results indicated that regardless of low-or high-molecular-weight PB-1,repeated annealing between 0 and 90℃could also promote formⅡto formⅠphase transition.The initial content of formⅠincreased with the heating and cooling cycles.The half-time of the phase transition(t_(1/2))was also shortened after heating/cooling.After 100 heating/cooling cycles,t_(1/2) was reduced to one-quarter of that without annealing,which had almost the same effect as the crystallization temperature at 25℃in promoting the phase transition.This study indicates that annealing after processing is also an important factor affecting the phase transition of PB-1,and should receive sufficient attention.
文摘Figure 6(a)in the paper[Chin.Phys.B 33074203(2024)]was incorrect due to editorial oversight.The correct figure is provided.This modification does not affect the result presented in the paper.
基金S.A.and M.Z.acknowledge support by NSF,grant number 2230352S.S.D.acknowledges support from the UVA Research Innovation AwardK.S.D.and D.L.work on TMDs has been supported by National Science Foundation Grant No.221949.
文摘Thermoelectric coolers utilizing the Peltier effect have dominated the field of solid-state cooling but their efficiency is hindered by material limitations.Alternative routes based on the Thomson and Nernst effects offer new possibilities.Here,we present a comprehensive investigation of the thermoelectric properties of 1T-TiSe_(2),focusing on these effects around the charge density wave transition(≈200 K).The abrupt Fermi surface reconstruction associated with this transition leads to an exceptional peak in the Thomson coefficient of 450μVK^(-1) at 184 K,surpassing the Seebeck coefficient.Furthermore,1T-TiSe_(2) exhibits a remarkably broad temperature range(170-400 K)with a Thomson coefficient exceeding 190μV K^(-1),a characteristic highly desirable for the development of practical Thomson coolers with extended operational ranges.Additionally,the Nernst coefficient exhibits an unusual temperature dependence,increasing with temperature in the normal phase,which we attribute to bipolar conduction effects.The combination of solid-solid pure electronic phase transition to a semimetallic phase with bipolar transport is identified as responsible for the unusual Nernst trend and the unusually large Thomson coefficient over a broad temperature range.
基金supported by the National Natural Science Foundation of China(No.52273025).
文摘The stretching-induced phase transition of biodegradable poly(butylene succinate)(PBS)was explored using a combination of mechanical testing and in situ wide angle X-ray diffraction characterization.The phase transition fromαphase toβphase can be effectively triggered by severe stretching,in which the threshold strain is dependent on the PBS crystallites.Interestingly,thisα-βphase transition can be reversed immediately once mechanical stretching begins to be released.It should be pointed out that the finish ofβ-αphase transition reversed,corresponding to the disappearance of the generatedβphase,does not necessarily need the external stretching to completely release.For the relaxation-reversed phase transition,the evolution of the normalizedβ-phase fraction exhibited a similar correlation with the stress released.It was indicated that the decay kinetics followed a stretching-dominant mechanism,and the amount ofβphase generated just prior to relaxation had a negligible influence on the reversed phase transition.
基金Project supported financially by the National Natural Science Foundation of China (Grant No. 52372100)the National Key Research and Development Program of China (Grant No. 2019YFA0307900)。
文摘Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effective Hamiltonian method in conjuction with the phase-field model, we have successfully reproduced the thermal hysteresis observed in ferroelectric materials during phase transitions. The computational results regarding the electrocaloric effect from these two different computational scales closely align with experimental measurements. Furthermore, we analyze how the first-order ferroelectric phase transition gradually diminishes with an increasing applied electric field, exhibiting characteristics of second-order-like phase transition. By employing the characteristic parameters of thermal hysteresis, we have established a pathway for calculations across different computational scales, thereby providing theoretical support for further investigations into the properties of ferroelectric materials through concurrent multiscale simulations.
基金supported by the Guangxi Natural Sci-ence Foundation(Grant Nos.2025GXNSFAA069277 and GuikeAD23026204).
文摘Laves-phase are among the most abundant groups of alloys with chemical formula AB_(2),known for their hightemperature strength and potential application in hydrogen storage.The Laves-phase generally acts as a strengthening agent,which enhances the strength and durability of alloys at extreme conditions.Consequently,the properties of Lavesphase alloys at extreme conditions attract wide attention.In this study,we investigated the high-pressure phase diagram of Laves-phase alloy HfZn_(2),and discovered a phase transition from C15(space group Fd3m)phase to C14(space group P63/mmc)phase at a pressure above 20 GPa.Based on ab initio simulations,the mechanical,chemical bonding and superconducting properties of high-pressure phase HfZn_(2)were predicted.The ratio of bulk modulus to shear modulus(B/G),a key indicator of mechanical properties in alloys,increases from 1.86 to 4.09 within the pressure range of 50-250 GPa,indicating excellent ductility of the C14 phase of HfZn_(2)under high pressure.Additionally,Zn gains approximately 0.43 electron from Hf at 10 GPa,and the superconducting critical temperature of HfZn_(2)is estimated to be around 0.55 K at 50 GPa.Given that both C14 and C15 phases are common structures in Laves-phase alloys,elucidating the high-pressure behaviors of C14 and C15 phases of HfZn_(2)will enhance the fundamental understanding of properties and potential applications at extreme conditions of Laves-phase alloys.
基金supported by the National Natural Science Foundation of China Key Program(No.U22A20420)Changzhou Leading Innovative Talents Introduction and Cultivation Project(No.CQ20230109)the Key Project of Jiangsu Provincial Basic Research Program(No.BK20243032)。
文摘P2-type layered oxide cathode materials have attracted extensive attention due to their simple preparation,high specific capacity,adjustable voltage range,and high packing density.However,the harmful phase transitions that occur at high voltage severely limit their practical application.Herein,a novel high-valence tungsten doped P2-Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)cathode material was prepared using the sol–gel method.Through diffusion kinetics analysis and in situ X-ray diffraction(in situ XRD),it has been proven that W^(6+)not only enhances the Na^(+)diffusion coefficient but also reduces the P2–O2 phase transition.The optimized NNMO-W1%delivers a high discharge specific capacity of 163 mAh·g^(-1)at 0.1C,and the capacity retention rate is as high as 77.6%after 1000 cycles at 10C.This is mainly due to that W^(6+)enters the lattice,optimizing the arrangement of primary particles.This work sheds light on the design and construction of high-performance layered oxides cathode materials.
基金Project supported by the National Key Research and Development Program of China (Grant Nos. 2021YFA1400900, 2021YFA0718300, and 2021YFA1402100)the National Natural Science Foundation of China (Grant Nos. 12174461, 12234012, 12334012, and 52327808)。
文摘We investigate the localization and topological properties of the Haldane model under the influence of random flux and Anderson disorder. Our localization analysis reveals that random flux induces a transition from insulating to metallic states, while Anderson localization only arises under the modulation of Anderson disorder. By employing real-space topological invariant methods, we demonstrates that the system undergoes topological phase transitions under different disorder manipulations, whereas random flux modulation uniquely induces topological Anderson insulator phases, with the potential to generate states with opposite Chern numbers. These findings highlight the distinct roles of disorder in shaping the interplay between topology and localization, providing insights into stabilizing topological states and designing robust topological quantum materials.
基金supported by the National Natural Science Foundation of China under Grant No.12175031Guangdong Provincial Key Laboratory of Nuclear Science under Grant No.2019B121203010。
文摘We investigate the boundary effect of quark–gluon plasma(QGP)droplets and the self-similarity effect of hadrons on QGP–hadron phase transition.In intermediate-or low-energy collisions,when the transverse momentum is below quantum chromodynamics(QCD)scale,QGP cannot be produced.However,if the transverse momentum changes to a relatively large value,a smallscale QGP droplet is produced.The modified MIT bag model with the multiple reflection expansion method is employed to study the QGP droplet with the curved boundary effect.It is found that the energy density,entropy density and pressure of QGP with the influence are smaller than those without the influence.In the hadron phase,we propose the two-body fractal model(TBFM)to study the self-similarity structure,arising from resonance,quantum correlation and interaction effects.It is observed that the energy density,entropy density and pressure increase due to the self-similarity structure.We calculate the transverse momentum spectra of pions with the self-similarity structure influence,which show good agreement with experimental data.Considering both boundary effect and self-similarity structure influence,our model predicts an increase in the transition temperature compared to the scenarios without these two effects in the High Intensity heavy-ion Accelerator Facility(HIAF)energy region,2.2 GeV to approximately 4.5 GeV.
