This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial ra...This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial rank no more than k has a lower bound.Furthermore,if k≤1 and normal elements are commuting,then the lower bound will be better.Another result establishes a connection involving the spectrum distance operator Dc between a C^(*)-algebra of stable rank one C^(*)-algebra and its hereditary C^(*)-subalgebra.展开更多
The complex chaotic behavior of a quasi-zero-stiffness(QZS)double-winged system with symmetric impact boundaries is investigated with Melnikov functions and numerical simulations.The analysis reveals the coexistence o...The complex chaotic behavior of a quasi-zero-stiffness(QZS)double-winged system with symmetric impact boundaries is investigated with Melnikov functions and numerical simulations.The analysis reveals the coexistence of multiple attractors.As a key mass parameter varies,the mechanism underlying degenerate singular closed orbits is elucidated,based upon which five distinct types of singular closed orbits are discovered,exhibiting both smooth and discontinuous(SD)characteristics.The chaotic threshold of each singular orbit is obtained by Melnikov functions and verified by numerical simulations.The numerical results further demonstrate the coexistence of SD motions.For zero damping systems,the Kolmogorov-Arnold-Moser(KAM)structures are exhibited to present the complex quasi-periodic and resonant behavior coexisting with chaotic and periodic motions.These findings advance the understanding of chaotic dynamics in nonsmooth multi-well impact systems.展开更多
In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadra...In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadratic and quadratic behaviors simultaneously in different variable components.展开更多
It is known that monotone recurrence relations can induce a class of twist homeomorphisms on the high-dimensional cylinder,which is an extension of the class of monotone twist maps on the annulus or two-dimensional cy...It is known that monotone recurrence relations can induce a class of twist homeomorphisms on the high-dimensional cylinder,which is an extension of the class of monotone twist maps on the annulus or two-dimensional cylinder.By constructing a bounded solution of the monotone recurrence relation,the main conclusion in this paper is acquired:The induced homeomorphism has Birkhoff orbits provided there is a compact forward-invariant set.Therefore,it generalizes Angenent's results in low-dimensional cases.展开更多
Aim To study singular points, closed orbits, stable manifolds and unstable manifolds of a second order autonomous Birkhoff system. Methods Qualitative methods of ordinary differential equation were used. Results and ...Aim To study singular points, closed orbits, stable manifolds and unstable manifolds of a second order autonomous Birkhoff system. Methods Qualitative methods of ordinary differential equation were used. Results and Conclusion The criteria for singular points, closed orbits and hyperbolic equilibrium points of a second order autonomous Birkhoff system are given. Moreover the stability of equilibria, stable manifolds and unstable manifolds are obtained.展开更多
Dear Editor,Idiopathic orbital inflammation(IOI),also known as orbital inflammatory pseudotumor,is a relatively common orbital disorder[1].Its pathogenesis remains unclear,often regarded as a nonspecific immune-mediat...Dear Editor,Idiopathic orbital inflammation(IOI),also known as orbital inflammatory pseudotumor,is a relatively common orbital disorder[1].Its pathogenesis remains unclear,often regarded as a nonspecific immune-mediated response[2].IOI presents with symptoms such as pain,photophobia,proptosis,eyelid swelling,edema,conjunctival congestion,and diplopia,with possible vision loss occurring in some cases.Based on the soft tissue structures involved,IOI can be classified into subtypes such as myositis,optic neuritis,dacryoadenitis,diffuse orbital inflammation,and orbital inflammatory masses[2].展开更多
In contrast to the main stream of studying the chaotic behavior of a given map, constructing chaotic map has attracted much less attention. In this paper, we propose simple analytical method for constructing one dime...In contrast to the main stream of studying the chaotic behavior of a given map, constructing chaotic map has attracted much less attention. In this paper, we propose simple analytical method for constructing one dimensional continuous maps with certain specific periodic points.Further, we obtain results for the existence of chaotic phenomenon in the sense of Li and Yorke. Some examples are also analyzed using the proposed methods.展开更多
The problem of maneuvering for a servicing spacecraft(inspector)to inspect a noncooperative spacecraft(evader)in cislunar space is investigated in this paper.The evader,which may be a malfunctioning or uncontrolled sa...The problem of maneuvering for a servicing spacecraft(inspector)to inspect a noncooperative spacecraft(evader)in cislunar space is investigated in this paper.The evader,which may be a malfunctioning or uncontrolled satellite,introduces uncertainties due to its potential maneuvering capabilities.To address this challenge,the scenario is modeled as a special orbital game,incorporating the unique complexities of the cislunar environment.A variable-duration,turn-based inspection and anti-inspection game model is designed.The model defines both players'rules,constraints,and victory conditions,providing a framework for non-cooperative inspection.Strategies for both players are developed and validated based on their dynamical properties.The inspector's strategy integrates two-body Lambert transfers with shooting methods,while the evader's strategy aims to maximize the inspector's fuel consumption.Simulation results show that the evader's optimal strategy involves deliberate fluctuations in its lunar periapsis altitude,with the inspector's requiredΔV up to eight times greater than the evader's.The impact of game constraints is evaluated,and the effectiveness of deploying the inspector in low lunar orbit is compared with the inspector at the Earth-Moon Lagrange point L1.The strengths and weaknesses of both are shown.These findings provide valuable insights for future orbital servicing and orbital games.展开更多
This paper proposes a threat assessment framework for non-cooperative satellites by analyzing their motion characteristics,developing a quantitative evaluation methodology,and demonstrating its effectiveness via repre...This paper proposes a threat assessment framework for non-cooperative satellites by analyzing their motion characteristics,developing a quantitative evaluation methodology,and demonstrating its effectiveness via representative scenarios with neural network acceleration.The framework first establishes a threat evaluation model that integrates three core parameters:capability,opportunity,and hidden values.Subsequently,this research systematically investigates the critical role of transfer windows in threat quantification and introduces a transfer window-based threat assessment approach.The proposed methodology is validated through multiple representative scenarios,with simulation results demonstrating superior performance compared to conventional methods relying solely on optimal transfer windows or minimum distance metrics,enabling more nuanced threat ranking in scenarios where traditional techniques prove inadequate.To address computational demands,a neural networkbased approximation system is implemented to achieve a 25,200×speedup(0.005 s vs.baseline 126 s per 1000-sample batch)through parallel processing,maintaining 99.3%accuracy.Finally,the study explores the framework's extensibility to diverse NCS objectives.It identifies discrepancies between intention inference models and threat evaluation paradigms,providing methodological insights for next-generation space domain awareness systems.展开更多
In a superconductor embedded with a quantum magnetic impurity,the Kondo effect is involved,leading to the competition between the Kondo singlet phase and the superconductivity phase.By means of the natural orbitals re...In a superconductor embedded with a quantum magnetic impurity,the Kondo effect is involved,leading to the competition between the Kondo singlet phase and the superconductivity phase.By means of the natural orbitals renormalization group(NORG)method,we revisit the problem of a quantum magnetic impurity coupled with a conventional s-wave superconductor.Here we present a detailed study focusing on the impurity spin polarization and susceptibility,the Kondo screening cloud,as well as the number and structures of the active natural orbitals(ANOs).In the superconducting phase,the impurity spin is partially polarized,indicating that the impurity remains partially screened by the quantum fluctuations.Furthermore,the impurity spin susceptibility becomes divergent,resulting from the presence of residual local moment formed at the impurity site.Correspondingly,a non-integral(incomplete)Kondo cloud is formed,although the ground state is a spin doublet in this phase.In comparison,the Kondo cloud is complete in the Kondo singlet phase as expected.We also quantify the critical point,where the quantum phase transition from a Kondo singlet phase to a superconducting phase occurs,which is consistent with that in previous works.On the other hand,it is illustrated that only one ANO emerges in both quantum phases.The structures of the ANO,projected into both the real space and momentum space,are distinct in the Kondo singlet phase from that in the superconducting phase.More specifically,in the Kondo singlet phase,the ANO keeps fully active with half-occupied,and the superconducting gap has negligible influence on its structure.On the contrary,in the superconducting phase,the ANO tends to be inactive and its structure changes significantly as the superconducting gap increases.Additionally,our investigation demonstrates that the NORG method is reliable and convenient to solve the quantum impurity problems in superconductors as well,which will promote further theoretical studies on the Kondo problems in such systems using numerical methods.展开更多
The design and fabrication of ordered epitaxial MOF-on-MOF heterostructures as highly efficient electrocatalysts for water splitting is crucial but still challenging.In this study,a simple coordination-driven self-ass...The design and fabrication of ordered epitaxial MOF-on-MOF heterostructures as highly efficient electrocatalysts for water splitting is crucial but still challenging.In this study,a simple coordination-driven self-assembly method is used to fabricate controllable MOF-on-MOF multiscale heterostructures,where triangular host MOF(ZIF-67)nanosheets undergo in situ epitaxial growth to form uniform orthogonal vip MOF(CoFe PBA)nanosheets.Phosphorus(P)is further introduced in situ to fabricate CoP and Fe_(2)P heterostructured nanosheets(CoFe-P-NS),which exhibit excellent bifunctional electrocatalytic performance due to the enhancement of intrinsic electrocatalytic activity by p-d orbital hybridization.Specifically,the CoFe-P-NS requires low overpotential of 259 and 307 mV to reach 500 mA cm−2 for HER and OER,respectively.Remarkably,the assembled electrolysis cell maintained a large current density of 300 mA cm−2 for over 360 h with negligible voltage increase during alkaline seawater electrolysis.Experiments and theoretical calculations show that the synergistic catalytic activity of bimetallic phosphides arises from p-d orbital hybridization,where the CoP-P sites enhance HER by optimizing H*adsorption in the Volmer-Heyrovsky steps,while the Fe_(2)P-Fe sites accelerate OER by lowering the energy barrier of the rate-determining step from O*to OOH*.This study provides valuable insights into the design of a controllable MOF-on-MOF-based electrocatalyst toward alkaline seawater splitting.展开更多
AIM:To investigate the clinical features and prognosis of patients with orbital inflammatory myofibroblastic tumor(IMT).METHODS:This retrospective study collected clinical data from 22 patients diagnosed with orbital ...AIM:To investigate the clinical features and prognosis of patients with orbital inflammatory myofibroblastic tumor(IMT).METHODS:This retrospective study collected clinical data from 22 patients diagnosed with orbital IMT based on histopathological examination.The patients were followed up to assess their prognosis.Clinical data from patients,including age,gender,course of disease,past medical history,primary symptoms,ophthalmologic examination findings,general condition,as well as imaging,laboratory,histopathological,and immunohistochemical results from digital records were collected.Orbital magnetic resonance imaging(MRI)and(or)computed tomography(CT)scans were performed to assess bone destruction of the mass,invasion of surrounding tissues,and any inflammatory changes in periorbital areas.RESULTS:The mean age of patients with orbital IMT was 28.24±3.30y,with a male-to-female ratio of 1.2:1.Main clinical manifestations were proptosis,blurred vision,palpable mass,and pain.Bone destruction and surrounding tissue invasion occurred in 72.73%and 54.55%of cases,respectively.Inflammatory changes in the periorbital site were observed in 77.27%of the patients.Hematoxylin and eosin staining showed proliferation of fibroblasts and myofibroblasts,accompanied by infiltration of lymphocytes and plasma cells.Immunohistochemical staining revealed that smooth muscle actin(SMA)and vimentin were positive in 100%of cases,while anaplastic lymphoma kinase(ALK)showed positivity in 47.37%.The recurrence rate of orbital IMT was 27.27%,and sarcomatous degeneration could occur.There were no significant correlations between recurrence and factors such as age,gender,laterality,duration of the disease,periorbital tissue invasion,bone destruction,periorbital inflammation,tumor size,fever,leukocytosis,or treatment(P>0.05).However,lymphadenopathy and a Ki-67 index of 10%or higher may be risk factors for recurrence(P=0.046;P=0.023).CONCLUSION:Orbital IMT is a locally invasive disease that may recur or lead to sarcomatoid degeneration,primarily affecting young and middle-aged patients.The presence of lymphadenopathy and a Ki-67 index of 10%or higher may signify a poor prognosis.展开更多
BACKGROUND:Maxillofacial trauma represents a significant challenge in emergency medicine,requiring both diagnostic accuracy and prompt intervention while balancing immediate life-saving interventions with preservation...BACKGROUND:Maxillofacial trauma represents a significant challenge in emergency medicine,requiring both diagnostic accuracy and prompt intervention while balancing immediate life-saving interventions with preservation of function and aesthetics.The complex anatomy of this region,with its proximity to critical structures,demands a thorough understanding of assessment and management principles.This narrative review aims to provide evidence-based guidelines for emergency physicians managing maxillofacial trauma,with particular emphasis on early recognition of critical injuries,airway management strategies,and special population considerations.METHODS:A narrative review was conducted via a comprehensive literature search of the PubMed and Scopus databases,which focused on maxillofacial trauma management in emergency settings.Articles were selected based on relevance to clinical practice,methodological quality,and current management guidelines.The review synthesized evidence from multiple study types,including original research,systematic reviews,and clinical practice guidelines,to provide practical guidance for emergency physicians.RESULTS:Initial assessment following Advanced Trauma Life Support(ATLS)principles is crucial,with airway management being a primary concern due to the risk of dynamic obstruction.Critical time-sensitive emergencies include orbital compartment syndrome,trapdoor fractures(in pediatric patients),and facial nerve injuries.Computed tomography(CT)imaging remains the gold standard for diagnosis.Special considerations are required for pediatric patients,who present unique anatomical challenges and injury patterns,and for elderly patients,who often have complex medical comorbidities and increased complication risks.Management strategies range from conservative treatment to urgent surgical intervention,with decisions based on the injury pattern and associated complications.CONCLUSION:Emergency physicians must maintain a structured yet fl exible approach to maxillofacial trauma,focusing on early recognition of critical injuries,appropriate airway management,and timely specialist consultation.Understanding injury patterns and their potential complications allows for eff ective risk stratifi cation and treatment planning,ultimately improving patient outcomes.展开更多
AIM:To define the prevalence and anatomical patterns of paranasal sinus abnormalities(PSA)in thyroid-associated ophthalmopathy(TAO)and to test the hypothesis that TAO is partially driven by contiguous orbital inflamma...AIM:To define the prevalence and anatomical patterns of paranasal sinus abnormalities(PSA)in thyroid-associated ophthalmopathy(TAO)and to test the hypothesis that TAO is partially driven by contiguous orbital inflammation rather than systemic autoimmunity or generalized orbital pressure.METHODS:Data included ophthalmic assessments and a panel of thyroid function and autoimmune biomarkers.Blinded radiological analysis of orbital computed tomography(CT)scans was performed to quantify sinus abnormalities and extraocular muscles(EOMs)involvement.Patients were categorized into two groups based on CT findings,those with no radiological evidence of sinus abnormalities(non-PSA control group)and those with identifiable PSA.Furthermore,ethmoid sinus mucosal biopsies from a subset of TAO patients and noninflammatory controls were subjected to histopathological analysis.RESULTS:Totally 121 TAO patients(mean age 42.4±12.8y,range 10-78y),male:female=42:79,were included.PSA was identified in 44.6%(n=54)of patients,with a distribution anatomically restricted to the maxillary(50.0%isolated)and ethmoid sinuses(18.5%isolated;29.6%combined).Compared to the non-PSA group(n=67),patients with PSA were significantly older(45.1±11.8 vs 40.3±13.2y;P=0.040)and were more likely to be male(55.6%vs 17.9%;P<0.001).They also had significantly higher proptosis(22.1±3.2 vs 20.7±2.9 mm;P<0.001).Medial/inferior rectus involvement was most frequent(88.4%vs 89.3%).Histopathological analysis of sinus mucosa from PSA patients provided direct evidence of pathology,revealing a dense,chronic lymphoplasmacytic infiltrate and submucosal edema,validating the radiological findings as a true inflammatory process.No significant correlation was found with systemic autoimmune markers,including thyroid-stimulating hormone(TSH)receptor antibodies(TRAb,median 4.86 vs 2.71 IU/L,P=0.104).CONCLUSION:TAO is associated with a high prevalence of PSA in a pattern consistent with the orbital anatomy.The correlation with ipsilateral muscle thickening combined with the lack of association with proptosis laterality or systemic biomarkers lend strong support to a model of contiguous inflammation over systemic autoimmunity,a hypothesis that warrants further validation through longitudinal and mechanistic studies.展开更多
Hard carbon is a vital anode material for sodium-ion batteries;however,the nonuniform growth of solid electrolyte interphase(SEI)film substantially diminishes its initial coulombic efficiency(ICE)and cycle life.The ch...Hard carbon is a vital anode material for sodium-ion batteries;however,the nonuniform growth of solid electrolyte interphase(SEI)film substantially diminishes its initial coulombic efficiency(ICE)and cycle life.The chemical and morphological properties of surface highly influence the electrode/electrolyte interfacial reactions.In this study,we have tuned orbital hybridization states forming an interface enriched with sp^(2) hybridized carbon(sp^(2)-C),which decreases the binding energy to solvent molecules and inhibits excessive solvent decomposition during SEI formation.Benefiting from successfully constructed inorganic-rich SEI,the ICE increased to 91%and sodium storage capacity reached 346 mAh/g.Besides,the capacity retention rate was 90.7%after 700 cycles at 1 A/g higher than pristine electrode(83.8%).展开更多
This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using d...This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.展开更多
The effect of plasma and charged particle interaction with spacecraft in a low Earth orbit(LEO)environment leads to ion focusing and the formation of an ion void in the downstream region as a result of charging.Simula...The effect of plasma and charged particle interaction with spacecraft in a low Earth orbit(LEO)environment leads to ion focusing and the formation of an ion void in the downstream region as a result of charging.Simulations and investigations using a fixed potential imposed on the spacecraft showed the nonsignificance of geophysical parameter changes to ion focusing.Variation of the temperature ratio(T_(r))contributed only to local ion focusing and manifested as two-ion streamers dispersed at the upper and lower edges of the spacecraft-the outermost layers of the satellite structure at the top and bottom,respectively.A simulation involving changing the ambient plasma density(N_(p))also showed the formation of local ion focusing,in which ions were more concentrated as the density increased.Furthermore,auroral electron density(N_(ae))variation had no clear impact on ion focusing,as indicated by static two-ion structures in the wake field.However,variation of the object potential(ϕ)strongly affected ion focusing formation,leading to distortion of the initial ion void region behind the spacecraft.The formation of ion focusing in this study was subject to the electric field produced by the object potential and the ambipolar electric field resulting from plasma expansion in the downstream region.展开更多
Motivated by the recent discovery of superconductivity in the kagome metal CsCr_(3)Sb_(5) under pressure,we theoretically investigate the superconducting pairing symmetry and the impact of spin–orbit coupling(SOC)in ...Motivated by the recent discovery of superconductivity in the kagome metal CsCr_(3)Sb_(5) under pressure,we theoretically investigate the superconducting pairing symmetry and the impact of spin–orbit coupling(SOC)in this system.By employing an effective four-orbital tight-binding model and solving the linearized gap equation within the random phase approximation,we find that the large inter-orbital spin fluctuations enhanced by Hund’s coupling promote a superconducting gap function with E_(2g)symmetry.The inclusion of SOC further stabilizes this gap symmetry.Our analysis also reveals that the d_(x^(2)-y^(2))orbital plays the dominant role in forming the superconducting pairs.展开更多
Developing high-performance Ni cathodes and understanding the relationship between electron states of Ni 3d orbital and energy storage mechanism from an atomic-orbital perspective are crucial yet challenging for alkal...Developing high-performance Ni cathodes and understanding the relationship between electron states of Ni 3d orbital and energy storage mechanism from an atomic-orbital perspective are crucial yet challenging for alkaline nickel-zinc batteries.Herein,we innovatively design P-NiMoO_(4)/NiSe_(2)heterostructures with rich oxygen vacancy via a selective component segregation.The P substitution in NiMoO_(4)activate Ni atoms,leading to the spin-state transition of Ni-3d orbitals from high-spin to low-spin,which promote the uniform and rapid nucleation of NiSe_(2)on the surface of NiMoO_(4)during subsequent selenization process.After selenization,the in situ formed P-NiMoO_(4)/NiSe_(2)heterostructures exhibits continuous increased unoccupied states of Ni 3d-orbitals and higher Ni valence state.The synergistic effect of P doping and selenization modulate the d-band center(ɛd)level of Ni 3d,thereby promoting d-p orbital hybridization between Ni 3d and O 2p of OH−as well as OH−adsorption ability.Consequently,the P-NiMoO_(4)/NiSe_(2)exhibits a top-level specific capacity of 390.7 mA h g^(−1)at 1 A g^(−1),2.8-fold higher than that of pristine NiMoO_(4),accompanied by remarkable rate capability and structural stability.Moreover,the assembled pouch-type battery and flexible devices demonstrate the practical application potential.This work provides fundamental insights into orbital-level engineering of battery materials for enhanced redox kinetics and cycling stability.展开更多
With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on pre...With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on predetermined refueling duration;however,the precise mission scheduling solution will be difficult to apply due to uncertain refueling duration caused by orbital transfer deviations and stochastic actuator faults during actual on-orbit service.Therefore,this paper proposes a robust mission scheduling strategy for geosynchronous orbit spacecraft on-orbit refueling missions with uncertain refueling duration.Firstly,a robust mission scheduling model is constructed by introducing the budget uncertainty set to describe the uncertain refueling duration.Secondly,a hybrid harris hawks optimization algorithm is designed to explore the optimal mission allocation and refueling sequences,which combines cubic chaotic mapping to initialize the population,and the crossover in the genetic algorithm is introduced to enhance global convergence.Finally,the typical simulation examples are constructed with real-mission scenarios in three aspects to analyze:performance comparisons with various algorithms;robustness analyses via comparisons of different on-orbit refueling durations;investigations into the impacts of different initial population strategies on algorithm performance,demonstrating the proposed mission scheduling framework's robustness and effectiveness by comparing it with the exact mission scheduling.展开更多
基金Supported by Zhejiang Provincial Natural Science Foundation of China(No.ZCLQN25A0103)。
文摘This paper studies certain estimates for the lower bound of distance between unitary orbits of normal elements.We show that the distance between unitary orbits of normal elements of simple C^(*)-algebras of tracial rank no more than k has a lower bound.Furthermore,if k≤1 and normal elements are commuting,then the lower bound will be better.Another result establishes a connection involving the spectrum distance operator Dc between a C^(*)-algebra of stable rank one C^(*)-algebra and its hereditary C^(*)-subalgebra.
基金Project supported by the National Natural Science Foundation of China(No.11732006)the China Scholarship Council。
文摘The complex chaotic behavior of a quasi-zero-stiffness(QZS)double-winged system with symmetric impact boundaries is investigated with Melnikov functions and numerical simulations.The analysis reveals the coexistence of multiple attractors.As a key mass parameter varies,the mechanism underlying degenerate singular closed orbits is elucidated,based upon which five distinct types of singular closed orbits are discovered,exhibiting both smooth and discontinuous(SD)characteristics.The chaotic threshold of each singular orbit is obtained by Melnikov functions and verified by numerical simulations.The numerical results further demonstrate the coexistence of SD motions.For zero damping systems,the Kolmogorov-Arnold-Moser(KAM)structures are exhibited to present the complex quasi-periodic and resonant behavior coexisting with chaotic and periodic motions.These findings advance the understanding of chaotic dynamics in nonsmooth multi-well impact systems.
基金supported by the NSFC(12301138)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2021L377)+1 种基金the Doctoral Scientific Research Foundation of Shanxi Datong University(2018-B-15)The second author’s work was supported by the NSFC(12171108).
文摘In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadratic and quadratic behaviors simultaneously in different variable components.
基金Supported by the National Natural Science Foundation of China(12201446)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB110005)the Shuangchuang Program of Jiangsu Province(JSSCBS20220898)。
文摘It is known that monotone recurrence relations can induce a class of twist homeomorphisms on the high-dimensional cylinder,which is an extension of the class of monotone twist maps on the annulus or two-dimensional cylinder.By constructing a bounded solution of the monotone recurrence relation,the main conclusion in this paper is acquired:The induced homeomorphism has Birkhoff orbits provided there is a compact forward-invariant set.Therefore,it generalizes Angenent's results in low-dimensional cases.
文摘Aim To study singular points, closed orbits, stable manifolds and unstable manifolds of a second order autonomous Birkhoff system. Methods Qualitative methods of ordinary differential equation were used. Results and Conclusion The criteria for singular points, closed orbits and hyperbolic equilibrium points of a second order autonomous Birkhoff system are given. Moreover the stability of equilibria, stable manifolds and unstable manifolds are obtained.
基金Supported by the National Natural Science Foundation of China(No.82388101,No.81930024)the Science and Technology Commission of Shanghai(No.22YS1400400,No.20DZ2270800).
文摘Dear Editor,Idiopathic orbital inflammation(IOI),also known as orbital inflammatory pseudotumor,is a relatively common orbital disorder[1].Its pathogenesis remains unclear,often regarded as a nonspecific immune-mediated response[2].IOI presents with symptoms such as pain,photophobia,proptosis,eyelid swelling,edema,conjunctival congestion,and diplopia,with possible vision loss occurring in some cases.Based on the soft tissue structures involved,IOI can be classified into subtypes such as myositis,optic neuritis,dacryoadenitis,diffuse orbital inflammation,and orbital inflammatory masses[2].
文摘In contrast to the main stream of studying the chaotic behavior of a given map, constructing chaotic map has attracted much less attention. In this paper, we propose simple analytical method for constructing one dimensional continuous maps with certain specific periodic points.Further, we obtain results for the existence of chaotic phenomenon in the sense of Li and Yorke. Some examples are also analyzed using the proposed methods.
基金supported by the National Key R&D Pro-gram of China:Gravitational Wave Detection Project(Nos.2021YFC2026,2021YFC2202601,2021YFC2202603)the National Natural Science Foundation of China(Nos.12172288 and 12472046)。
文摘The problem of maneuvering for a servicing spacecraft(inspector)to inspect a noncooperative spacecraft(evader)in cislunar space is investigated in this paper.The evader,which may be a malfunctioning or uncontrolled satellite,introduces uncertainties due to its potential maneuvering capabilities.To address this challenge,the scenario is modeled as a special orbital game,incorporating the unique complexities of the cislunar environment.A variable-duration,turn-based inspection and anti-inspection game model is designed.The model defines both players'rules,constraints,and victory conditions,providing a framework for non-cooperative inspection.Strategies for both players are developed and validated based on their dynamical properties.The inspector's strategy integrates two-body Lambert transfers with shooting methods,while the evader's strategy aims to maximize the inspector's fuel consumption.Simulation results show that the evader's optimal strategy involves deliberate fluctuations in its lunar periapsis altitude,with the inspector's requiredΔV up to eight times greater than the evader's.The impact of game constraints is evaluated,and the effectiveness of deploying the inspector in low lunar orbit is compared with the inspector at the Earth-Moon Lagrange point L1.The strengths and weaknesses of both are shown.These findings provide valuable insights for future orbital servicing and orbital games.
基金supported by the National Key R&D Programof China:Gravitational Wave Detection Project(Grant Nos.2021YFC2026,2021YFC2202601,2021YFC2202603)the Na-tional Natural Science Foundation of China(Grant Nos.12172288and 12472046)。
文摘This paper proposes a threat assessment framework for non-cooperative satellites by analyzing their motion characteristics,developing a quantitative evaluation methodology,and demonstrating its effectiveness via representative scenarios with neural network acceleration.The framework first establishes a threat evaluation model that integrates three core parameters:capability,opportunity,and hidden values.Subsequently,this research systematically investigates the critical role of transfer windows in threat quantification and introduces a transfer window-based threat assessment approach.The proposed methodology is validated through multiple representative scenarios,with simulation results demonstrating superior performance compared to conventional methods relying solely on optimal transfer windows or minimum distance metrics,enabling more nuanced threat ranking in scenarios where traditional techniques prove inadequate.To address computational demands,a neural networkbased approximation system is implemented to achieve a 25,200×speedup(0.005 s vs.baseline 126 s per 1000-sample batch)through parallel processing,maintaining 99.3%accuracy.Finally,the study explores the framework's extensibility to diverse NCS objectives.It identifies discrepancies between intention inference models and threat evaluation paradigms,providing methodological insights for next-generation space domain awareness systems.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12104247 and 11934020)。
文摘In a superconductor embedded with a quantum magnetic impurity,the Kondo effect is involved,leading to the competition between the Kondo singlet phase and the superconductivity phase.By means of the natural orbitals renormalization group(NORG)method,we revisit the problem of a quantum magnetic impurity coupled with a conventional s-wave superconductor.Here we present a detailed study focusing on the impurity spin polarization and susceptibility,the Kondo screening cloud,as well as the number and structures of the active natural orbitals(ANOs).In the superconducting phase,the impurity spin is partially polarized,indicating that the impurity remains partially screened by the quantum fluctuations.Furthermore,the impurity spin susceptibility becomes divergent,resulting from the presence of residual local moment formed at the impurity site.Correspondingly,a non-integral(incomplete)Kondo cloud is formed,although the ground state is a spin doublet in this phase.In comparison,the Kondo cloud is complete in the Kondo singlet phase as expected.We also quantify the critical point,where the quantum phase transition from a Kondo singlet phase to a superconducting phase occurs,which is consistent with that in previous works.On the other hand,it is illustrated that only one ANO emerges in both quantum phases.The structures of the ANO,projected into both the real space and momentum space,are distinct in the Kondo singlet phase from that in the superconducting phase.More specifically,in the Kondo singlet phase,the ANO keeps fully active with half-occupied,and the superconducting gap has negligible influence on its structure.On the contrary,in the superconducting phase,the ANO tends to be inactive and its structure changes significantly as the superconducting gap increases.Additionally,our investigation demonstrates that the NORG method is reliable and convenient to solve the quantum impurity problems in superconductors as well,which will promote further theoretical studies on the Kondo problems in such systems using numerical methods.
基金financial support of the National Natural Science Foundation of China (21875247,21072221, 21172252)the Project of Talent Cultivation for Carbon Peak and Carbon Neutrality of the University of Chinese of Academy of Science
文摘The design and fabrication of ordered epitaxial MOF-on-MOF heterostructures as highly efficient electrocatalysts for water splitting is crucial but still challenging.In this study,a simple coordination-driven self-assembly method is used to fabricate controllable MOF-on-MOF multiscale heterostructures,where triangular host MOF(ZIF-67)nanosheets undergo in situ epitaxial growth to form uniform orthogonal vip MOF(CoFe PBA)nanosheets.Phosphorus(P)is further introduced in situ to fabricate CoP and Fe_(2)P heterostructured nanosheets(CoFe-P-NS),which exhibit excellent bifunctional electrocatalytic performance due to the enhancement of intrinsic electrocatalytic activity by p-d orbital hybridization.Specifically,the CoFe-P-NS requires low overpotential of 259 and 307 mV to reach 500 mA cm−2 for HER and OER,respectively.Remarkably,the assembled electrolysis cell maintained a large current density of 300 mA cm−2 for over 360 h with negligible voltage increase during alkaline seawater electrolysis.Experiments and theoretical calculations show that the synergistic catalytic activity of bimetallic phosphides arises from p-d orbital hybridization,where the CoP-P sites enhance HER by optimizing H*adsorption in the Volmer-Heyrovsky steps,while the Fe_(2)P-Fe sites accelerate OER by lowering the energy barrier of the rate-determining step from O*to OOH*.This study provides valuable insights into the design of a controllable MOF-on-MOF-based electrocatalyst toward alkaline seawater splitting.
基金Supported by the National Key R&D Program of China(No.2023YFC2410203)Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support(No.ZLRK202503).
文摘AIM:To investigate the clinical features and prognosis of patients with orbital inflammatory myofibroblastic tumor(IMT).METHODS:This retrospective study collected clinical data from 22 patients diagnosed with orbital IMT based on histopathological examination.The patients were followed up to assess their prognosis.Clinical data from patients,including age,gender,course of disease,past medical history,primary symptoms,ophthalmologic examination findings,general condition,as well as imaging,laboratory,histopathological,and immunohistochemical results from digital records were collected.Orbital magnetic resonance imaging(MRI)and(or)computed tomography(CT)scans were performed to assess bone destruction of the mass,invasion of surrounding tissues,and any inflammatory changes in periorbital areas.RESULTS:The mean age of patients with orbital IMT was 28.24±3.30y,with a male-to-female ratio of 1.2:1.Main clinical manifestations were proptosis,blurred vision,palpable mass,and pain.Bone destruction and surrounding tissue invasion occurred in 72.73%and 54.55%of cases,respectively.Inflammatory changes in the periorbital site were observed in 77.27%of the patients.Hematoxylin and eosin staining showed proliferation of fibroblasts and myofibroblasts,accompanied by infiltration of lymphocytes and plasma cells.Immunohistochemical staining revealed that smooth muscle actin(SMA)and vimentin were positive in 100%of cases,while anaplastic lymphoma kinase(ALK)showed positivity in 47.37%.The recurrence rate of orbital IMT was 27.27%,and sarcomatous degeneration could occur.There were no significant correlations between recurrence and factors such as age,gender,laterality,duration of the disease,periorbital tissue invasion,bone destruction,periorbital inflammation,tumor size,fever,leukocytosis,or treatment(P>0.05).However,lymphadenopathy and a Ki-67 index of 10%or higher may be risk factors for recurrence(P=0.046;P=0.023).CONCLUSION:Orbital IMT is a locally invasive disease that may recur or lead to sarcomatoid degeneration,primarily affecting young and middle-aged patients.The presence of lymphadenopathy and a Ki-67 index of 10%or higher may signify a poor prognosis.
文摘BACKGROUND:Maxillofacial trauma represents a significant challenge in emergency medicine,requiring both diagnostic accuracy and prompt intervention while balancing immediate life-saving interventions with preservation of function and aesthetics.The complex anatomy of this region,with its proximity to critical structures,demands a thorough understanding of assessment and management principles.This narrative review aims to provide evidence-based guidelines for emergency physicians managing maxillofacial trauma,with particular emphasis on early recognition of critical injuries,airway management strategies,and special population considerations.METHODS:A narrative review was conducted via a comprehensive literature search of the PubMed and Scopus databases,which focused on maxillofacial trauma management in emergency settings.Articles were selected based on relevance to clinical practice,methodological quality,and current management guidelines.The review synthesized evidence from multiple study types,including original research,systematic reviews,and clinical practice guidelines,to provide practical guidance for emergency physicians.RESULTS:Initial assessment following Advanced Trauma Life Support(ATLS)principles is crucial,with airway management being a primary concern due to the risk of dynamic obstruction.Critical time-sensitive emergencies include orbital compartment syndrome,trapdoor fractures(in pediatric patients),and facial nerve injuries.Computed tomography(CT)imaging remains the gold standard for diagnosis.Special considerations are required for pediatric patients,who present unique anatomical challenges and injury patterns,and for elderly patients,who often have complex medical comorbidities and increased complication risks.Management strategies range from conservative treatment to urgent surgical intervention,with decisions based on the injury pattern and associated complications.CONCLUSION:Emergency physicians must maintain a structured yet fl exible approach to maxillofacial trauma,focusing on early recognition of critical injuries,appropriate airway management,and timely specialist consultation.Understanding injury patterns and their potential complications allows for eff ective risk stratifi cation and treatment planning,ultimately improving patient outcomes.
基金Supported by The National Natural Science Foundation of China(No.82101180)the Fund for Beijing Science&Technology Development of TCM(No.BJZYYB-2023-17)the Beijing Municipal Natural Science Foundation grant(No.7252093).
文摘AIM:To define the prevalence and anatomical patterns of paranasal sinus abnormalities(PSA)in thyroid-associated ophthalmopathy(TAO)and to test the hypothesis that TAO is partially driven by contiguous orbital inflammation rather than systemic autoimmunity or generalized orbital pressure.METHODS:Data included ophthalmic assessments and a panel of thyroid function and autoimmune biomarkers.Blinded radiological analysis of orbital computed tomography(CT)scans was performed to quantify sinus abnormalities and extraocular muscles(EOMs)involvement.Patients were categorized into two groups based on CT findings,those with no radiological evidence of sinus abnormalities(non-PSA control group)and those with identifiable PSA.Furthermore,ethmoid sinus mucosal biopsies from a subset of TAO patients and noninflammatory controls were subjected to histopathological analysis.RESULTS:Totally 121 TAO patients(mean age 42.4±12.8y,range 10-78y),male:female=42:79,were included.PSA was identified in 44.6%(n=54)of patients,with a distribution anatomically restricted to the maxillary(50.0%isolated)and ethmoid sinuses(18.5%isolated;29.6%combined).Compared to the non-PSA group(n=67),patients with PSA were significantly older(45.1±11.8 vs 40.3±13.2y;P=0.040)and were more likely to be male(55.6%vs 17.9%;P<0.001).They also had significantly higher proptosis(22.1±3.2 vs 20.7±2.9 mm;P<0.001).Medial/inferior rectus involvement was most frequent(88.4%vs 89.3%).Histopathological analysis of sinus mucosa from PSA patients provided direct evidence of pathology,revealing a dense,chronic lymphoplasmacytic infiltrate and submucosal edema,validating the radiological findings as a true inflammatory process.No significant correlation was found with systemic autoimmune markers,including thyroid-stimulating hormone(TSH)receptor antibodies(TRAb,median 4.86 vs 2.71 IU/L,P=0.104).CONCLUSION:TAO is associated with a high prevalence of PSA in a pattern consistent with the orbital anatomy.The correlation with ipsilateral muscle thickening combined with the lack of association with proptosis laterality or systemic biomarkers lend strong support to a model of contiguous inflammation over systemic autoimmunity,a hypothesis that warrants further validation through longitudinal and mechanistic studies.
基金support from the Heilongjiang Province"Double First Class"Discipline Collaborative Innovation Project(No.LJGXCG2023-061).
文摘Hard carbon is a vital anode material for sodium-ion batteries;however,the nonuniform growth of solid electrolyte interphase(SEI)film substantially diminishes its initial coulombic efficiency(ICE)and cycle life.The chemical and morphological properties of surface highly influence the electrode/electrolyte interfacial reactions.In this study,we have tuned orbital hybridization states forming an interface enriched with sp^(2) hybridized carbon(sp^(2)-C),which decreases the binding energy to solvent molecules and inhibits excessive solvent decomposition during SEI formation.Benefiting from successfully constructed inorganic-rich SEI,the ICE increased to 91%and sodium storage capacity reached 346 mAh/g.Besides,the capacity retention rate was 90.7%after 700 cycles at 1 A/g higher than pristine electrode(83.8%).
基金supported by the National Natural Science Foundation of China(32302258,32172317)the Science and Technology Innovation Program of Hunan Province(2024RC3185)+1 种基金Hunan Provincial Natural Science Foundation of China(2023JJ40317)Changsha Municipal Natural Science Foundation(kq2202223).
文摘This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.
基金Kobe Universitythe National Research and Innovation Agency (BRIN)
文摘The effect of plasma and charged particle interaction with spacecraft in a low Earth orbit(LEO)environment leads to ion focusing and the formation of an ion void in the downstream region as a result of charging.Simulations and investigations using a fixed potential imposed on the spacecraft showed the nonsignificance of geophysical parameter changes to ion focusing.Variation of the temperature ratio(T_(r))contributed only to local ion focusing and manifested as two-ion streamers dispersed at the upper and lower edges of the spacecraft-the outermost layers of the satellite structure at the top and bottom,respectively.A simulation involving changing the ambient plasma density(N_(p))also showed the formation of local ion focusing,in which ions were more concentrated as the density increased.Furthermore,auroral electron density(N_(ae))variation had no clear impact on ion focusing,as indicated by static two-ion structures in the wake field.However,variation of the object potential(ϕ)strongly affected ion focusing formation,leading to distortion of the initial ion void region behind the spacecraft.The formation of ion focusing in this study was subject to the electric field produced by the object potential and the ambipolar electric field resulting from plasma expansion in the downstream region.
基金supported by the National Key Research and Development of China(Grant Nos.2024YFA1408104 and 2021YFA1400400)the National Natural Science Foundation of China(Grant Nos.12374137,12434005,12074175,92165205,12004191,and 12550405)the Natural Science Foundation of Jiangsu Province(Grant No.BK20233001)。
文摘Motivated by the recent discovery of superconductivity in the kagome metal CsCr_(3)Sb_(5) under pressure,we theoretically investigate the superconducting pairing symmetry and the impact of spin–orbit coupling(SOC)in this system.By employing an effective four-orbital tight-binding model and solving the linearized gap equation within the random phase approximation,we find that the large inter-orbital spin fluctuations enhanced by Hund’s coupling promote a superconducting gap function with E_(2g)symmetry.The inclusion of SOC further stabilizes this gap symmetry.Our analysis also reveals that the d_(x^(2)-y^(2))orbital plays the dominant role in forming the superconducting pairs.
基金supported by the National Natural Science Foundation of China (Grant no. 22209083)
文摘Developing high-performance Ni cathodes and understanding the relationship between electron states of Ni 3d orbital and energy storage mechanism from an atomic-orbital perspective are crucial yet challenging for alkaline nickel-zinc batteries.Herein,we innovatively design P-NiMoO_(4)/NiSe_(2)heterostructures with rich oxygen vacancy via a selective component segregation.The P substitution in NiMoO_(4)activate Ni atoms,leading to the spin-state transition of Ni-3d orbitals from high-spin to low-spin,which promote the uniform and rapid nucleation of NiSe_(2)on the surface of NiMoO_(4)during subsequent selenization process.After selenization,the in situ formed P-NiMoO_(4)/NiSe_(2)heterostructures exhibits continuous increased unoccupied states of Ni 3d-orbitals and higher Ni valence state.The synergistic effect of P doping and selenization modulate the d-band center(ɛd)level of Ni 3d,thereby promoting d-p orbital hybridization between Ni 3d and O 2p of OH−as well as OH−adsorption ability.Consequently,the P-NiMoO_(4)/NiSe_(2)exhibits a top-level specific capacity of 390.7 mA h g^(−1)at 1 A g^(−1),2.8-fold higher than that of pristine NiMoO_(4),accompanied by remarkable rate capability and structural stability.Moreover,the assembled pouch-type battery and flexible devices demonstrate the practical application potential.This work provides fundamental insights into orbital-level engineering of battery materials for enhanced redox kinetics and cycling stability.
基金co-supported by the National Natural Science Foundation of China(Nos.62473110,62403166)the Fundamental Research Funds for the Central Universities,China(No.2023FRFK02043)+1 种基金the Natural Science Foundation of Heilongjiang Province,China(No.LH2022F023)the National Key Laboratory of Space Intelligent Control Foundation,China(No.2023-JCJQ-LB-006-19)。
文摘With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on predetermined refueling duration;however,the precise mission scheduling solution will be difficult to apply due to uncertain refueling duration caused by orbital transfer deviations and stochastic actuator faults during actual on-orbit service.Therefore,this paper proposes a robust mission scheduling strategy for geosynchronous orbit spacecraft on-orbit refueling missions with uncertain refueling duration.Firstly,a robust mission scheduling model is constructed by introducing the budget uncertainty set to describe the uncertain refueling duration.Secondly,a hybrid harris hawks optimization algorithm is designed to explore the optimal mission allocation and refueling sequences,which combines cubic chaotic mapping to initialize the population,and the crossover in the genetic algorithm is introduced to enhance global convergence.Finally,the typical simulation examples are constructed with real-mission scenarios in three aspects to analyze:performance comparisons with various algorithms;robustness analyses via comparisons of different on-orbit refueling durations;investigations into the impacts of different initial population strategies on algorithm performance,demonstrating the proposed mission scheduling framework's robustness and effectiveness by comparing it with the exact mission scheduling.
