Using quantum hydrodynamic approaches, we study the quantum pressure correction to the collective excitation spectrum of the interacting trapped superfluid Fermi gases in the BEC-BCS crossover. Based on a phenomenolog...Using quantum hydrodynamic approaches, we study the quantum pressure correction to the collective excitation spectrum of the interacting trapped superfluid Fermi gases in the BEC-BCS crossover. Based on a phenomenological equation of state, we derive hydrodynamic equations of the system in the whole BEC-BCS crossover regime. Beyond the Thomas-Fermi approximation, expressions of the frequency corrections of collective modes for both spherical and axial symmetric traps excited in the BEC-BCS crossover are given explicitly. The corrections of the eigenfrequencies due to the quantum pressure and their dependence on the inverse interaction strength, anisotropic parameter and particle numbers of the condensate are discussed in detail.展开更多
An effective relativistic continuum massive Proca Lagrangian action is used to account for the Lorentzvector condensation effects on the equation of state of the strongly interacting fermions system.The interior quant...An effective relativistic continuum massive Proca Lagrangian action is used to account for the Lorentzvector condensation effects on the equation of state of the strongly interacting fermions system.The interior quantumfluctuation effects are incorporated as an external field approximation indirectly through a fictive generalized ThomsonProblem counterterm background.The general analytical formulas for the d-dimensional thermodynamics are given nearthe unitary limit region,In the non-relativistic limit for d=3,the universal dimensionless coefficientε=4/9 andenergy gap △/ε_f=5/18 are reasonably consistent with the existing theoretical and experimental results.In the unitarylimit for d=2 and T=0,the universal coefficient can even approach the extreme occasion ξ=0 corresponding to theinfinite effective fermion mass m~*=∞,which can be mapped to the strongly coupled two-dimensional electrons and isquite similar to the three-dimensional Bose-Einstein condensation of ideal boson gas.Instead,for d=1,the universalcoefficient ξ is negative,implying the non-existence of phase transition from superfluidity to normal state.The solutionsmanifest the quantum Ising universal class characteristic of the strongly coupled unitary fermions gas.展开更多
A theoretical study of the BCS-BEC crossover is presented. Starting from a two-channel Boson-Fermion resonance model, the BCS-Bogoiubov mean-field method and the Green＇s function method are adopted. The result shows ...A theoretical study of the BCS-BEC crossover is presented. Starting from a two-channel Boson-Fermion resonance model, the BCS-Bogoiubov mean-field method and the Green＇s function method are adopted. The result shows that we can end up with a BCS-type theory but with a composite order parameter. Calculation shows that the Bose condensate of BCS Cooper pairs is proportional to the molecular BEC of Bose molecules. The resonance superfluid phase is indicated by the energy spectrum with an obvious interpretation of the transition mechanism.展开更多
We observe characteristic atomic behaviors in the Bose-Einstein-condensation-Bardeen-Cooper-Schrieffer(BEC-BCS)crossover,by accurately tuning the magnetic field across the Feshbach resonance of lithium atoms.The magne...We observe characteristic atomic behaviors in the Bose-Einstein-condensation-Bardeen-Cooper-Schrieffer(BEC-BCS)crossover,by accurately tuning the magnetic field across the Feshbach resonance of lithium atoms.The magnetic field is calibrated by measuring the Zeeman shift of the optical transition.A non-monotonic anisotropic expansion is observed across the Feshbach resonance.The density distribution is explored in different interacting regimes,where a condensate of diatomic molecules forms in the BEC limit with the indication of a bimodal distribution.We also measure the three-body recombination atom loss in the BEC-BCS crossover,and find that the magnetic field of the maximum atom loss is in the BEC limit and gets closer to the Feshbach resonance when decreasing the atom temperature,which agrees with previous experiments and theoretical prediction.This work builds up a controllable platform for the study on the strongly interacting Fermi gas.展开更多
We report on the measurement of shear viscosity in an ultracold Fermi gas with variable temperatures and tunable interactions.A quadrupole mode excitation in an isotropic harmonic trap is used to quantify the shear vi...We report on the measurement of shear viscosity in an ultracold Fermi gas with variable temperatures and tunable interactions.A quadrupole mode excitation in an isotropic harmonic trap is used to quantify the shear viscosity of the quantum gas within the hydrodynamic regime.The shear viscosity of the system as a function of temperature has been investigated,and the results closely align with calculations in the high-temperature limit utilizing a new definition of the cutoff radius.Through an adiabatic sweep across the Bardeen–Cooper–Schrieffer(BCS)to Bose–Einstein condensate(BEC)crossover,we find that the minimum value of the shear viscosity,as a function of interaction strength,is significantly shifted toward the BEC side.Furthermore,the behavior of the shear viscosity is asymmetric on both sides of the location of the minimum.展开更多
A predictive model of meiotic crossover engineering would increase precision in crop breeding.We review the biological principles underlying crossover formation and chromosomal distribution,hierarchical control mechan...A predictive model of meiotic crossover engineering would increase precision in crop breeding.We review the biological principles underlying crossover formation and chromosomal distribution,hierarchical control mechanisms enforcing crossover assurance,and an emerging phase-separation model determining crossover interference patterning.展开更多
Thermoelectric materials,capable of converting temperature gradients into electrical power,have been traditionally limited by a trade-off between thermopower and electrical conductivity.This study introduces a novel,b...Thermoelectric materials,capable of converting temperature gradients into electrical power,have been traditionally limited by a trade-off between thermopower and electrical conductivity.This study introduces a novel,broadly applicable approach that enhances both the spin-driven thermopower and the thermoelectric figure-of-merit(zT)without compromising electrical conductivity,using temperature-driven spin crossover.Our approach,supported by both theoretical and experimental evidence,is demonstrated through a case study of chromium doped-manganese telluride,but is not confined to this material and can be extended to other magnetic materials.By introducing dopants to create a high crystal field and exploiting the entropy changes associated with temperature-driven spin crossover,we achieved a significant increase in thermopower,by approximately 136μV K^(-1),representing more than a 200%enhancement at elevated temperatures within the paramagnetic domain.Our exploration of the bipolar semiconducting nature of these materials reveals that suppressing bipolar magnon/paramagnon-drag thermopower is key to understanding and utilizing spin crossover-driven thermopower.These findings,validated by inelastic neutron scattering,X-ray photoemission spectroscopy,thermal transport,and energy conversion measurements,shed light on crucial material design parameters.We provide a comprehensive framework that analyzes the interplay between spin entropy,hopping transport,and magnon/paramagnon lifetimes,paving the way for the development of high-performance spin-driven thermoelectric materials.展开更多
The interplay between dimensionality and superconductivity is a central theme in understanding the behavior of low-dimensional superconductors. In this work, we investigate the dimensional crossover from quasi-two-dim...The interplay between dimensionality and superconductivity is a central theme in understanding the behavior of low-dimensional superconductors. In this work, we investigate the dimensional crossover from quasi-two-dimensional(quasi-2D) to three-dimensional(3D) superconductivity in(Li,Fe)OHFeSe_(1-x)S_(x) single crystals driven by sulfur doping.Through detailed structural, electrical, and magnetic characterization, we identify a critical doping level(x = 0.53) where the system transitions from quasi-2D to 3D superconducting behavior. Reduced superconducting fluctuations and nonFermi liquid behavior near this critical point suggest the presence of competition between intralayer and interlayer pairing mechanisms. Fluctuation conductivity analysis reveals that the coherence length along the c-axis, ζ_(c)(0), and the interlayer coupling strength, Γ, increase significantly at x = 0.53, marking the onset of 3D superconductivity. These findings provide new insights into the role of dimensionality and interlayer coupling in modulating superconducting properties, positioning(Li,Fe)OHFeSe_(1-x)S_(x) as a unique platform for exploring crossover physics in iron-based superconductors.展开更多
In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more...In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more Li+during charge and discharge processes due to the increased Ni content in their crystal structure,thereby providing higher energy density.However,a significant challenge associated with Ni-rich layered oxide cathodes is the crossover effect,which arises from the dissolution of Ni^(2+)from the cathode,leading to a rapid decline in battery capacity.Through the delocalization-induced effect of solvent molecules,Ni^(2+)is transformed into a fluorinated transition metal inorganic phase layer,thereby forming a corrosion-resistant Li metal interface.This prevents solvent molecules from being reduced and degraded by Li metal anode.The surface of the Li metal anode exhibits a smooth and flat deposition morphology after long-term cycling.Furthermore,the introduction of Ni^(2+)can enhance the concentration gradient of transition metal ions near the cathode,thereby suppressing the dissolution process of transition metal ions.Even the NCM955 cathode with a mass load of 22 mg cm^(−2)also has great capacity retention after cycling.The Ni^(2+)induced by high electronegative functional groups of solvent under the electron delocalization effect,preventing the Ni ions dissolution of cathode and constructing a corrosion-resistant Li metal interface layer.This work provides new insights into suppressing crossover effects in Li metal batteries with high nickel cathodes.展开更多
This study introduces a novel mathematical model to describe the progression of cholera by integrating fractional derivatives with both singular and non-singular kernels alongside stochastic differential equations ove...This study introduces a novel mathematical model to describe the progression of cholera by integrating fractional derivatives with both singular and non-singular kernels alongside stochastic differential equations over four distinct time intervals.The model incorporates three key fractional derivatives:the Caputo-Fabrizio fractional derivative with a non-singular kernel,the Caputo proportional constant fractional derivative with a singular kernel,and the Atangana-Baleanu fractional derivative with a non-singular kernel.We analyze the stability of the core model and apply various numerical methods to approximate the proposed crossover model.To achieve this,the approximation of Caputo proportional constant fractional derivative with Grünwald-Letnikov nonstandard finite difference method is used for the deterministic model with a singular kernel,while the Toufik-Atangana method is employed for models involving a non-singular Mittag-Leffler kernel.Additionally,the integral Caputo-Fabrizio approximation and a two-step Lagrange polynomial are utilized to approximate the model with a non-singular exponential decay kernel.For the stochastic component,the Milstein method is implemented to approximate the stochastic differential equations.The stability and effectiveness of the proposed model and methodologies are validated through numerical simulations and comparisons with real-world cholera data from Yemen.The results confirm the reliability and practical applicability of the model,providing strong theoretical and empirical support for the approach.展开更多
Recent advancements in computational and database technologies have led to the exponential growth of large-scale medical datasets,significantly increasing data complexity and dimensionality in medical diagnostics.Effi...Recent advancements in computational and database technologies have led to the exponential growth of large-scale medical datasets,significantly increasing data complexity and dimensionality in medical diagnostics.Efficient feature selection methods are critical for improving diagnostic accuracy,reducing computational costs,and enhancing the interpretability of predictive models.Particle Swarm Optimization(PSO),a widely used metaheuristic inspired by swarm intelligence,has shown considerable promise in feature selection tasks.However,conventional PSO often suffers from premature convergence and limited exploration capabilities,particularly in high-dimensional spaces.To overcome these limitations,this study proposes an enhanced PSO framework incorporating Orthogonal Initializa-tion and a Crossover Operator(OrPSOC).Orthogonal Initialization ensures a diverse and uniformly distributed initial particle population,substantially improving the algorithm’s exploration capability.The Crossover Operator,inspired by genetic algorithms,introduces additional diversity during the search process,effectively mitigating premature convergence and enhancing global search performance.The effectiveness of OrPSOC was rigorously evaluated on three benchmark medical datasets—Colon,Leukemia,and Prostate Tumor.Comparative analyses were conducted against traditional filter-based methods,including Fast Clustering-Based Feature Selection Technique(Fast-C),Minimum Redundancy Maximum Relevance(MinRedMaxRel),and Five-Way Joint Mutual Information(FJMI),as well as prominent metaheuristic algorithms such as standard PSO,Ant Colony Optimization(ACO),Comprehensive Learning Gravitational Search Algorithm(CLGSA),and Fuzzy-Based CLGSA(FCLGSA).Experimental results demonstrated that OrPSOC consistently outperformed these existing methods in terms of classification accuracy,computational efficiency,and result stability,achieving significant improvements even with fewer selected features.Additionally,a sensitivity analysis of the crossover parameter provided valuable insights into parameter tuning and its impact on model performance.These findings highlight the superiority and robustness of the proposed OrPSOC approach for feature selection in medical diagnostic applications and underscore its potential for broader adoption in various high-dimensional,data-driven fields.展开更多
SrRuO_(3)is a canonical itinerant ferromagnet,yet its properties in the extreme two-dimensional limit on a(111)crystal plane remain largely unexplored.Here,we demonstrate a complete transformation of its ground state ...SrRuO_(3)is a canonical itinerant ferromagnet,yet its properties in the extreme two-dimensional limit on a(111)crystal plane remain largely unexplored.Here,we demonstrate a complete transformation of its ground state driven by dimensional reduction.As the thickness of(111)-oriented SrRuO_(3)films is reduced to a few unit cells,the system transitions from a metallic ferromagnet to a semiconducting antiferromagnet.This emergent antiferromagnetism is evidenced by a vanishing magnetic remanence and most strikingly,by the appearance of an unconventional twelve-fold anisotropic magnetoresistance.First-principles calculations confirm that an A-type antiferromagnetic order is the stable ground state in the ultrathin limit.Our findings establish(111)dimensional engineering as a powerful route to manipulate correlated electron states and uncover novel functionalities for antiferromagnetic spintronics.展开更多
Background:Whether lactated Ringer's solution is clinically superior to normal saline for routine intravenous administration of fluids is uncertain.Methods:In an open-label,two-period,two-sequence,cross-sectional,...Background:Whether lactated Ringer's solution is clinically superior to normal saline for routine intravenous administration of fluids is uncertain.Methods:In an open-label,two-period,two-sequence,cross-sectional,cluster-randomized,crossover trial,we assigned hospitals in Ontario,Canada,to use either lactated Ringer's solution or normal saline hospital-wide for a period of 12 weeks.展开更多
We investigate the mixed-state entanglement between two spins embedded in the XXZ Heisenberg chain under thermal equilibrium.By deriving an analytical expression for the entanglement of two-spin thermal states and ext...We investigate the mixed-state entanglement between two spins embedded in the XXZ Heisenberg chain under thermal equilibrium.By deriving an analytical expression for the entanglement of two-spin thermal states and extending this analysis to larger spin chains,we demonstrate that mixed-state entanglement is profoundly shaped by both disorder and temperature.Our results reveal a sharp distinction between many-body localized and ergodic phases,with entanglement vanishing above diferent fnite temperature thresholds.Furthermore,by analyzing non-adjacent spins,we uncover an approximate exponential decay of entanglement with separation.This work advances the understanding of the quantum-to-classical transition by linking the entanglement properties of small subsystems to the broader thermal environment,ofering an explanation for the absence of entanglement in macroscopic systems.These fndings provide critical insights into quantum many-body physics,bridging concepts from thermalization,localization,and quantum information theory.展开更多
Transducing thermal energy into mechanical movements via molecular reconfigurations offers a cutting-edge approach to thermal actuating materials,which could be applied to sensors,energy harvesting and storage devices...Transducing thermal energy into mechanical movements via molecular reconfigurations offers a cutting-edge approach to thermal actuating materials,which could be applied to sensors,energy harvesting and storage devices[1].Thermal expansion is a pivotal aspect in solid state chemistry,intricately intertwined with various factors such as crystal structure,chemical composition,electronic configuration,microstructure,and defects.Most materials undergo isotropic and positive thermal expansion(PTE)because of the disharmonic vibrational amplitudes of their chemical bonds.Moreover,anisotropic thermal expansion(ATE)and negative thermal expansion(NTE)are fascinating physical attributes of solids,which can originate from electronic or magnetic mechanisms,as well as through a transverse phonon mechanism in insulating lattice solids.展开更多
In eukaryotes, crossovers together with sister chromatid cohesion maintain physical association between homologous chromosomes, ensuring accurate chromosome segregation during meiosis I and resulting in exchange of ge...In eukaryotes, crossovers together with sister chromatid cohesion maintain physical association between homologous chromosomes, ensuring accurate chromosome segregation during meiosis I and resulting in exchange of genetic information between homologues. The Arabidopsis PTD （Parting Dancers） gene affects the level of meiotic crossover formation, but its functional relationships with other core meiotic genes, such as AtSP011-1, AtRAD51, and AtMSH4, are unclear; whether PTD has other functions in meiosis is also unknown. To further analyze PTD function and to test for epistatic relationships, we compared the meiotic chromosome behaviors ofAtspoll-1 ptd and Atrad51 ptd double mutants with the relevant single mutants. The results suggest that PTD functions downstream of AtSP011-1 and AtRAD51 in the meiotic recombination pathway. Furthermore, we found that meiotic defects in rck pM and Atmsh4 ptd double mutants showed similar meiotic phenotypes to those of the relevant single mutants, providing genetic evidences for roles of PTD and RCK in the type I crossovers pathway. Moreover, we employed a pollen tetrad-based fluorescence method and found that the meiotic crossover frequencies in two genetic intervals were significantly reduced from 6.63% and 22.26% in wild-type to 1.14% and 6.36%, respectively, in the ptd^2 mutant. These results revealed new aspects of PTD function in meiotic crossover formation.展开更多
Repairing DNA double-strand breaks(DSBs)with homologous chromosomes as templates is the hallmark of meiosis.The critical outcome of meiotic homologous recombination is crossovers,which ensure faithful chromosome segre...Repairing DNA double-strand breaks(DSBs)with homologous chromosomes as templates is the hallmark of meiosis.The critical outcome of meiotic homologous recombination is crossovers,which ensure faithful chromosome segregation and promote genetic diversity of progenies.Crossover patterns are tightly controlled and exhibit three characteristics:obligatory crossover,crossover interference,and crossover homeostasis.Aberrant crossover patterns are the leading cause of infertility,miscarriage,and congenital disease.Crossover recombination occurs in the context of meiotic chromosomes,and it is tightly integrated with and regulated by meiotic chromosome structure both locally and globally.Meiotic chromosomes are organized in a loop-axis architecture.Diverse evidence shows that chromosome axis length determines crossover frequency.Interestingly,short chromosomes show different crossover patterns compared to long chromosomes.A high frequency of human embryos are aneuploid,primarily derived from female meiosis errors.Dramatically increased aneuploidy in older women is the well-known“maternal age effect.”However,a high frequency of aneuploidy also occurs in young women,derived from crossover maturation inefficiency in human females.In addition,frequency of human aneuploidy also shows other age-dependent alterations.Here,current advances in the understanding of these issues are reviewed,regulation of crossover patterns by meiotic chromosomes are discussed,and issues that remain to be investigated are suggested.展开更多
Digital nerve injuries are the mostly detected nerve injury in the upper extremity. However, since the clinical phenomenon of crossover innervation at some degree from uninjured digital nerve to the in- jured side occ...Digital nerve injuries are the mostly detected nerve injury in the upper extremity. However, since the clinical phenomenon of crossover innervation at some degree from uninjured digital nerve to the in- jured side occurs after digital nerve injuries is sustained, one could argue that this concept might even result in the overestimation of the outcome of the digital nerve repair. With this knowledge in mind, this study aimed to present novel, pure, focused and valuable clinical data by comparing the outcomes of bilateral and unilateral digital nerve repair. A retrospective review of 28 fingers with unilateral or bilateral digital nerve repair using end-to-end technique in 19 patients within 2 years was performed. Weber＇s two-point discrimination, sharp/dull discrimination, warm/cold sensation and Visual Analog Scale scoring were measured at final 12-month follow ups in all patients. There was no significant difference in recovery of sensibility after unilateral and bilateral digital nerve repairs. Though there is crossover innervation microscopically, it is not important in the clinical evaluation period. According to clinical findings from this study, crossover innervations appear to be negligible in the estimation of outcomes of digital neurorrhaphy.展开更多
In order to improve the tracking performance in this paper following TBD(Track before Detection) framework multi-level crossover and matching operator is presented.In data association stage the greedy principle is ado...In order to improve the tracking performance in this paper following TBD(Track before Detection) framework multi-level crossover and matching operator is presented.In data association stage the greedy principle is adopted to handle time complexity in DPA and at the same time crossover mathing operator is given to construct candidate trajectory.In addition the corresponding strategy is introduced in preprocessing and postprocessing to remove clutter and suppress false alarm rate.By the experimental comparison and analysis it can be found that the method is more perfer to strengthen the tracking performance of targets with SNR < 2.0 dB.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos 10574028, 10775032 and J0730310)
文摘Using quantum hydrodynamic approaches, we study the quantum pressure correction to the collective excitation spectrum of the interacting trapped superfluid Fermi gases in the BEC-BCS crossover. Based on a phenomenological equation of state, we derive hydrodynamic equations of the system in the whole BEC-BCS crossover regime. Beyond the Thomas-Fermi approximation, expressions of the frequency corrections of collective modes for both spherical and axial symmetric traps excited in the BEC-BCS crossover are given explicitly. The corrections of the eigenfrequencies due to the quantum pressure and their dependence on the inverse interaction strength, anisotropic parameter and particle numbers of the condensate are discussed in detail.
基金the Scientific Starting Research Fund of Central China Normal UniversityNational Natural Science Foundation of China under Grant No.10675052
文摘An effective relativistic continuum massive Proca Lagrangian action is used to account for the Lorentzvector condensation effects on the equation of state of the strongly interacting fermions system.The interior quantumfluctuation effects are incorporated as an external field approximation indirectly through a fictive generalized ThomsonProblem counterterm background.The general analytical formulas for the d-dimensional thermodynamics are given nearthe unitary limit region,In the non-relativistic limit for d=3,the universal dimensionless coefficientε=4/9 andenergy gap △/ε_f=5/18 are reasonably consistent with the existing theoretical and experimental results.In the unitarylimit for d=2 and T=0,the universal coefficient can even approach the extreme occasion ξ=0 corresponding to theinfinite effective fermion mass m~*=∞,which can be mapped to the strongly coupled two-dimensional electrons and isquite similar to the three-dimensional Bose-Einstein condensation of ideal boson gas.Instead,for d=1,the universalcoefficient ξ is negative,implying the non-existence of phase transition from superfluidity to normal state.The solutionsmanifest the quantum Ising universal class characteristic of the strongly coupled unitary fermions gas.
文摘A theoretical study of the BCS-BEC crossover is presented. Starting from a two-channel Boson-Fermion resonance model, the BCS-Bogoiubov mean-field method and the Green＇s function method are adopted. The result shows that we can end up with a BCS-type theory but with a composite order parameter. Calculation shows that the Bose condensate of BCS Cooper pairs is proportional to the molecular BEC of Bose molecules. The resonance superfluid phase is indicated by the energy spectrum with an obvious interpretation of the transition mechanism.
基金the National Key Research and Development Program of China(Grant No.2016YFA0301503)the National Natural Science Foundation of China(Grant Nos.11674358,11434015,and 11974384)+1 种基金Chinese Academy of Sciences(Grant No.YJKYYQ20170025)K.C.Wong Education Foundation(Grant No.GJTD-2019-15).
文摘We observe characteristic atomic behaviors in the Bose-Einstein-condensation-Bardeen-Cooper-Schrieffer(BEC-BCS)crossover,by accurately tuning the magnetic field across the Feshbach resonance of lithium atoms.The magnetic field is calibrated by measuring the Zeeman shift of the optical transition.A non-monotonic anisotropic expansion is observed across the Feshbach resonance.The density distribution is explored in different interacting regimes,where a condensate of diatomic molecules forms in the BEC limit with the indication of a bimodal distribution.We also measure the three-body recombination atom loss in the BEC-BCS crossover,and find that the magnetic field of the maximum atom loss is in the BEC limit and gets closer to the Feshbach resonance when decreasing the atom temperature,which agrees with previous experiments and theoretical prediction.This work builds up a controllable platform for the study on the strongly interacting Fermi gas.
基金supported by the National Key R&D Program(Grant No.2022YFA1404102)the National Natural Science Foundation of China(Grant Nos.U23A2073,12374250,and 12121004)+1 种基金Chinese Academy of Sciences(Grant No.YJKYYQ20170025)Hubei Province(Grant No.2021CFA027).
文摘We report on the measurement of shear viscosity in an ultracold Fermi gas with variable temperatures and tunable interactions.A quadrupole mode excitation in an isotropic harmonic trap is used to quantify the shear viscosity of the quantum gas within the hydrodynamic regime.The shear viscosity of the system as a function of temperature has been investigated,and the results closely align with calculations in the high-temperature limit utilizing a new definition of the cutoff radius.Through an adiabatic sweep across the Bardeen–Cooper–Schrieffer(BCS)to Bose–Einstein condensate(BEC)crossover,we find that the minimum value of the shear viscosity,as a function of interaction strength,is significantly shifted toward the BEC side.Furthermore,the behavior of the shear viscosity is asymmetric on both sides of the location of the minimum.
基金funded by the National Natural Science Foundation of China(U2102219 and 32370901)the Project of Zhongshan Biological Breeding Laboratory(ZSBBL-KY2023-06-3).
文摘A predictive model of meiotic crossover engineering would increase precision in crop breeding.We review the biological principles underlying crossover formation and chromosomal distribution,hierarchical control mechanisms enforcing crossover assurance,and an emerging phase-separation model determining crossover interference patterning.
基金funding support by the National Science Foundation(NSF)under grant numbers CBET-2110603the Air Force Office of Scientific Research(AFOSR)under contract number FA9550-12-1-0225supported by the State of North Carolina and the National Science Foundation(award number ECCS-2025064).
文摘Thermoelectric materials,capable of converting temperature gradients into electrical power,have been traditionally limited by a trade-off between thermopower and electrical conductivity.This study introduces a novel,broadly applicable approach that enhances both the spin-driven thermopower and the thermoelectric figure-of-merit(zT)without compromising electrical conductivity,using temperature-driven spin crossover.Our approach,supported by both theoretical and experimental evidence,is demonstrated through a case study of chromium doped-manganese telluride,but is not confined to this material and can be extended to other magnetic materials.By introducing dopants to create a high crystal field and exploiting the entropy changes associated with temperature-driven spin crossover,we achieved a significant increase in thermopower,by approximately 136μV K^(-1),representing more than a 200%enhancement at elevated temperatures within the paramagnetic domain.Our exploration of the bipolar semiconducting nature of these materials reveals that suppressing bipolar magnon/paramagnon-drag thermopower is key to understanding and utilizing spin crossover-driven thermopower.These findings,validated by inelastic neutron scattering,X-ray photoemission spectroscopy,thermal transport,and energy conversion measurements,shed light on crucial material design parameters.We provide a comprehensive framework that analyzes the interplay between spin entropy,hopping transport,and magnon/paramagnon lifetimes,paving the way for the development of high-performance spin-driven thermoelectric materials.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 52272268, 52250308, and 52102338)Beijing National Laboratory for Condensed Matter Physics (Grant No. 2024BNLCMPKF016)Fundamental Research Funding of Universities directly under the Chinese Central Government (Grant No. 2-9-2022-038)。
文摘The interplay between dimensionality and superconductivity is a central theme in understanding the behavior of low-dimensional superconductors. In this work, we investigate the dimensional crossover from quasi-two-dimensional(quasi-2D) to three-dimensional(3D) superconductivity in(Li,Fe)OHFeSe_(1-x)S_(x) single crystals driven by sulfur doping.Through detailed structural, electrical, and magnetic characterization, we identify a critical doping level(x = 0.53) where the system transitions from quasi-2D to 3D superconducting behavior. Reduced superconducting fluctuations and nonFermi liquid behavior near this critical point suggest the presence of competition between intralayer and interlayer pairing mechanisms. Fluctuation conductivity analysis reveals that the coherence length along the c-axis, ζ_(c)(0), and the interlayer coupling strength, Γ, increase significantly at x = 0.53, marking the onset of 3D superconductivity. These findings provide new insights into the role of dimensionality and interlayer coupling in modulating superconducting properties, positioning(Li,Fe)OHFeSe_(1-x)S_(x) as a unique platform for exploring crossover physics in iron-based superconductors.
基金the support from Yunnan Fundamental Research Projects(202301BE070001-029,202401CF070129,202501CF070181)National Natural Science Foundation of China(22209012,22479067)Kunming University of Science and Technology Analysis and Testing Fund Support Project(2023T20220172)。
文摘In order to maximize the advantages of high energy density in Li metal batteries,it is necessary to match cathode materials with high specific capacities.Ni-rich layered oxides have been shown to reversibly embed more Li+during charge and discharge processes due to the increased Ni content in their crystal structure,thereby providing higher energy density.However,a significant challenge associated with Ni-rich layered oxide cathodes is the crossover effect,which arises from the dissolution of Ni^(2+)from the cathode,leading to a rapid decline in battery capacity.Through the delocalization-induced effect of solvent molecules,Ni^(2+)is transformed into a fluorinated transition metal inorganic phase layer,thereby forming a corrosion-resistant Li metal interface.This prevents solvent molecules from being reduced and degraded by Li metal anode.The surface of the Li metal anode exhibits a smooth and flat deposition morphology after long-term cycling.Furthermore,the introduction of Ni^(2+)can enhance the concentration gradient of transition metal ions near the cathode,thereby suppressing the dissolution process of transition metal ions.Even the NCM955 cathode with a mass load of 22 mg cm^(−2)also has great capacity retention after cycling.The Ni^(2+)induced by high electronegative functional groups of solvent under the electron delocalization effect,preventing the Ni ions dissolution of cathode and constructing a corrosion-resistant Li metal interface layer.This work provides new insights into suppressing crossover effects in Li metal batteries with high nickel cathodes.
文摘This study introduces a novel mathematical model to describe the progression of cholera by integrating fractional derivatives with both singular and non-singular kernels alongside stochastic differential equations over four distinct time intervals.The model incorporates three key fractional derivatives:the Caputo-Fabrizio fractional derivative with a non-singular kernel,the Caputo proportional constant fractional derivative with a singular kernel,and the Atangana-Baleanu fractional derivative with a non-singular kernel.We analyze the stability of the core model and apply various numerical methods to approximate the proposed crossover model.To achieve this,the approximation of Caputo proportional constant fractional derivative with Grünwald-Letnikov nonstandard finite difference method is used for the deterministic model with a singular kernel,while the Toufik-Atangana method is employed for models involving a non-singular Mittag-Leffler kernel.Additionally,the integral Caputo-Fabrizio approximation and a two-step Lagrange polynomial are utilized to approximate the model with a non-singular exponential decay kernel.For the stochastic component,the Milstein method is implemented to approximate the stochastic differential equations.The stability and effectiveness of the proposed model and methodologies are validated through numerical simulations and comparisons with real-world cholera data from Yemen.The results confirm the reliability and practical applicability of the model,providing strong theoretical and empirical support for the approach.
文摘Recent advancements in computational and database technologies have led to the exponential growth of large-scale medical datasets,significantly increasing data complexity and dimensionality in medical diagnostics.Efficient feature selection methods are critical for improving diagnostic accuracy,reducing computational costs,and enhancing the interpretability of predictive models.Particle Swarm Optimization(PSO),a widely used metaheuristic inspired by swarm intelligence,has shown considerable promise in feature selection tasks.However,conventional PSO often suffers from premature convergence and limited exploration capabilities,particularly in high-dimensional spaces.To overcome these limitations,this study proposes an enhanced PSO framework incorporating Orthogonal Initializa-tion and a Crossover Operator(OrPSOC).Orthogonal Initialization ensures a diverse and uniformly distributed initial particle population,substantially improving the algorithm’s exploration capability.The Crossover Operator,inspired by genetic algorithms,introduces additional diversity during the search process,effectively mitigating premature convergence and enhancing global search performance.The effectiveness of OrPSOC was rigorously evaluated on three benchmark medical datasets—Colon,Leukemia,and Prostate Tumor.Comparative analyses were conducted against traditional filter-based methods,including Fast Clustering-Based Feature Selection Technique(Fast-C),Minimum Redundancy Maximum Relevance(MinRedMaxRel),and Five-Way Joint Mutual Information(FJMI),as well as prominent metaheuristic algorithms such as standard PSO,Ant Colony Optimization(ACO),Comprehensive Learning Gravitational Search Algorithm(CLGSA),and Fuzzy-Based CLGSA(FCLGSA).Experimental results demonstrated that OrPSOC consistently outperformed these existing methods in terms of classification accuracy,computational efficiency,and result stability,achieving significant improvements even with fewer selected features.Additionally,a sensitivity analysis of the crossover parameter provided valuable insights into parameter tuning and its impact on model performance.These findings highlight the superiority and robustness of the proposed OrPSOC approach for feature selection in medical diagnostic applications and underscore its potential for broader adoption in various high-dimensional,data-driven fields.
基金supported by the National Natural Science Foundation of China(Grant Nos.12204521,12250710675,and 12504198)the National Key R&D Program of China(Grant No.2022YFA1403000)。
文摘SrRuO_(3)is a canonical itinerant ferromagnet,yet its properties in the extreme two-dimensional limit on a(111)crystal plane remain largely unexplored.Here,we demonstrate a complete transformation of its ground state driven by dimensional reduction.As the thickness of(111)-oriented SrRuO_(3)films is reduced to a few unit cells,the system transitions from a metallic ferromagnet to a semiconducting antiferromagnet.This emergent antiferromagnetism is evidenced by a vanishing magnetic remanence and most strikingly,by the appearance of an unconventional twelve-fold anisotropic magnetoresistance.First-principles calculations confirm that an A-type antiferromagnetic order is the stable ground state in the ultrathin limit.Our findings establish(111)dimensional engineering as a powerful route to manipulate correlated electron states and uncover novel functionalities for antiferromagnetic spintronics.
文摘Background:Whether lactated Ringer's solution is clinically superior to normal saline for routine intravenous administration of fluids is uncertain.Methods:In an open-label,two-period,two-sequence,cross-sectional,cluster-randomized,crossover trial,we assigned hospitals in Ontario,Canada,to use either lactated Ringer's solution or normal saline hospital-wide for a period of 12 weeks.
基金supported by the National Natural Science Foundation of China(Grant Nos.92365202,12475011,and 11921005)the National Key R&D Program of China(Grant No.2024YFA1409002)Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)。
文摘We investigate the mixed-state entanglement between two spins embedded in the XXZ Heisenberg chain under thermal equilibrium.By deriving an analytical expression for the entanglement of two-spin thermal states and extending this analysis to larger spin chains,we demonstrate that mixed-state entanglement is profoundly shaped by both disorder and temperature.Our results reveal a sharp distinction between many-body localized and ergodic phases,with entanglement vanishing above diferent fnite temperature thresholds.Furthermore,by analyzing non-adjacent spins,we uncover an approximate exponential decay of entanglement with separation.This work advances the understanding of the quantum-to-classical transition by linking the entanglement properties of small subsystems to the broader thermal environment,ofering an explanation for the absence of entanglement in macroscopic systems.These fndings provide critical insights into quantum many-body physics,bridging concepts from thermalization,localization,and quantum information theory.
基金supported by the National Natural Science Foundation of China(22171155)Natural Science Foundation of Shandong Province(ZR2022YQ07)Taishan Scholar Program(tsqn202306166).
文摘Transducing thermal energy into mechanical movements via molecular reconfigurations offers a cutting-edge approach to thermal actuating materials,which could be applied to sensors,energy harvesting and storage devices[1].Thermal expansion is a pivotal aspect in solid state chemistry,intricately intertwined with various factors such as crystal structure,chemical composition,electronic configuration,microstructure,and defects.Most materials undergo isotropic and positive thermal expansion(PTE)because of the disharmonic vibrational amplitudes of their chemical bonds.Moreover,anisotropic thermal expansion(ATE)and negative thermal expansion(NTE)are fascinating physical attributes of solids,which can originate from electronic or magnetic mechanisms,as well as through a transverse phonon mechanism in insulating lattice solids.
基金supported by funds from Fudan Universityfunds from Rijk Zwaan,the Netherlands,and the Biology Department and the Huck Institutes of the Life Sciences at the Pennsylvania State University in USA
文摘In eukaryotes, crossovers together with sister chromatid cohesion maintain physical association between homologous chromosomes, ensuring accurate chromosome segregation during meiosis I and resulting in exchange of genetic information between homologues. The Arabidopsis PTD （Parting Dancers） gene affects the level of meiotic crossover formation, but its functional relationships with other core meiotic genes, such as AtSP011-1, AtRAD51, and AtMSH4, are unclear; whether PTD has other functions in meiosis is also unknown. To further analyze PTD function and to test for epistatic relationships, we compared the meiotic chromosome behaviors ofAtspoll-1 ptd and Atrad51 ptd double mutants with the relevant single mutants. The results suggest that PTD functions downstream of AtSP011-1 and AtRAD51 in the meiotic recombination pathway. Furthermore, we found that meiotic defects in rck pM and Atmsh4 ptd double mutants showed similar meiotic phenotypes to those of the relevant single mutants, providing genetic evidences for roles of PTD and RCK in the type I crossovers pathway. Moreover, we employed a pollen tetrad-based fluorescence method and found that the meiotic crossover frequencies in two genetic intervals were significantly reduced from 6.63% and 22.26% in wild-type to 1.14% and 6.36%, respectively, in the ptd^2 mutant. These results revealed new aspects of PTD function in meiotic crossover formation.
基金This work is supported by grants from the National Key R&D Program of China(2018YFC1003700,2018YFC1003400)National Natural Science Foundation of China(31671293,31801203,and 31890782).
文摘Repairing DNA double-strand breaks(DSBs)with homologous chromosomes as templates is the hallmark of meiosis.The critical outcome of meiotic homologous recombination is crossovers,which ensure faithful chromosome segregation and promote genetic diversity of progenies.Crossover patterns are tightly controlled and exhibit three characteristics:obligatory crossover,crossover interference,and crossover homeostasis.Aberrant crossover patterns are the leading cause of infertility,miscarriage,and congenital disease.Crossover recombination occurs in the context of meiotic chromosomes,and it is tightly integrated with and regulated by meiotic chromosome structure both locally and globally.Meiotic chromosomes are organized in a loop-axis architecture.Diverse evidence shows that chromosome axis length determines crossover frequency.Interestingly,short chromosomes show different crossover patterns compared to long chromosomes.A high frequency of human embryos are aneuploid,primarily derived from female meiosis errors.Dramatically increased aneuploidy in older women is the well-known“maternal age effect.”However,a high frequency of aneuploidy also occurs in young women,derived from crossover maturation inefficiency in human females.In addition,frequency of human aneuploidy also shows other age-dependent alterations.Here,current advances in the understanding of these issues are reviewed,regulation of crossover patterns by meiotic chromosomes are discussed,and issues that remain to be investigated are suggested.
文摘Digital nerve injuries are the mostly detected nerve injury in the upper extremity. However, since the clinical phenomenon of crossover innervation at some degree from uninjured digital nerve to the in- jured side occurs after digital nerve injuries is sustained, one could argue that this concept might even result in the overestimation of the outcome of the digital nerve repair. With this knowledge in mind, this study aimed to present novel, pure, focused and valuable clinical data by comparing the outcomes of bilateral and unilateral digital nerve repair. A retrospective review of 28 fingers with unilateral or bilateral digital nerve repair using end-to-end technique in 19 patients within 2 years was performed. Weber＇s two-point discrimination, sharp/dull discrimination, warm/cold sensation and Visual Analog Scale scoring were measured at final 12-month follow ups in all patients. There was no significant difference in recovery of sensibility after unilateral and bilateral digital nerve repairs. Though there is crossover innervation microscopically, it is not important in the clinical evaluation period. According to clinical findings from this study, crossover innervations appear to be negligible in the estimation of outcomes of digital neurorrhaphy.
基金Sponsored by the Young Talent Program of Fujian Province (Grant No.2007F3097)
文摘In order to improve the tracking performance in this paper following TBD(Track before Detection) framework multi-level crossover and matching operator is presented.In data association stage the greedy principle is adopted to handle time complexity in DPA and at the same time crossover mathing operator is given to construct candidate trajectory.In addition the corresponding strategy is introduced in preprocessing and postprocessing to remove clutter and suppress false alarm rate.By the experimental comparison and analysis it can be found that the method is more perfer to strengthen the tracking performance of targets with SNR < 2.0 dB.
