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Lower Bound of Distance Between Unitary Orbits of Normal Elements in C^(*)-algebras of Tracial Rank One
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作者 WANG Ruofei LUO Zheng 《数学进展》 北大核心 2026年第1期171-182,共12页
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
关键词 unitary orbit hereditary C^(*)-subalgebra tracial rank one lower bound
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Tocilizumab as an effective treatment option for idiopathic orbital inflammation:a case report and literature review
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作者 Hai-Yang Zhang Hui-Jie Zhang Hui-Fang Zhou 《International Journal of Ophthalmology(English edition)》 2026年第1期199-201,共3页
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
关键词 soft tissue structures idiopathic orbital inflammation orbital disorder its vision loss myositisoptic neuriti orbital inflammatory pseudotumoris orbital inflammation ioi also orbital inflammatory pseudotumor
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Game-theoretic maneuvering strategies for orbital inspection of non-cooperative spacecraft in cislunar space
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作者 Hongyu HAN Zhaohui DANG 《Chinese Journal of Aeronautics》 2026年第1期385-397,共13页
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
关键词 Cislunar Impulsive maneuver Non-cooperative target orbital game orbital transfer
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Numerical study of a quantum spin in an s-wave superconductor using the natural orbitals renormalization group method
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作者 Wen-Jing Zhang Ru Zheng +1 位作者 Rong-Qiang He Zhong-Yi Lu 《Chinese Physics B》 2026年第2期538-547,共10页
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
关键词 Kondo effect SUPERCONDUCTOR natural orbitals renormalization group active natural orbitals
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p-d Orbital hybridization enhanced MOF-on-MOF derived CoP/Fe_(2)P bimetallic phosphide electrocatalyst for stable water electrolysis
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作者 Enhong Liu Yunqiao Guo +4 位作者 Jiayang Zhao Haotian Zhang Yongjian Zhao Pengfei Yuan Rui Song 《Journal of Energy Chemistry》 2026年第1期198-207,I0005,共11页
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
关键词 MOF-on-MOF heterostructures CoFe-P-NS Bifunctional electrocatalyst Seawater electrolysis p-d orbital hybridization
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Clinical features and prognosis of orbital inflammatory myofibroblastic tumor
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作者 Jing Li Liang-Yuan Xu +9 位作者 Nan Wang Rui Liu Shan-Feng Zhao Ting-Ting Ren Qi-Han Guo Bin Zhang Hong Zhang Hai-Han Yan Yu-Fei Zhang Jian-Min Ma 《International Journal of Ophthalmology(English edition)》 2026年第1期105-114,共10页
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
关键词 inflammatory myofibroblastic tumor orbital disease clinical features PROGNOSIS
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Contiguous orbital inflammation from paranasal sinus abnormalities in etiology of thyroid-associated ophthalmopathy
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作者 Xin-Xin Hao Yang-Xu Tao +2 位作者 Xiang Xu Ming-Ming Liu Yang Li 《International Journal of Ophthalmology(English edition)》 2026年第1期97-104,共8页
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
关键词 thyroid-associated ophthalmopathy paranasal sinus abnormalities PROPTOSIS orbital inflammation
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Orbital hybridization states of carbon assisted robust inorganic-rich solid electrolyte interphase towards high initial coulombic efficiency hard carbon anode
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作者 Zeren Zhou Yixiang Zhang +4 位作者 Qixian Zhang Qiaoyan Lin Yong Shuai Zhijiang Wang Lishuang Fan 《Chinese Chemical Letters》 2026年第2期540-544,共5页
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
关键词 Sodium-ion battery Hard carbon orbital hybridization Solid electrolyte interphase Initial Coulombic efficiency
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Singular closed orbits and chaotic behavior of a double-winged quasi-zero-stiffness system
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作者 Xinyi HUANG S.LENCI Qingjie CAO 《Applied Mathematics and Mechanics(English Edition)》 2026年第3期509-534,I0005-I0006,共28页
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
关键词 chaotic behavior Melnikov function singular closed orbit Kolmogorov-Arnold-Moser(KAM)structure RESONANCE
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Case studies of ion focusing in the downstream region of a modeled low Earth orbit spacecraft
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作者 Nizam Ahmad Hideyuki Usui +4 位作者 Yohei Miyake Slamet Supriadi Hanif Fakhrurroja Hilman Syaeful Alam Harry Bangkit 《Earth and Planetary Physics》 2026年第1期136-143,共8页
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
关键词 ion focusing spacecraft potential low Earth orbit environment
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Pressure-induced superconductivity in kagome metal CsCr_(3)Sb_(5):Role of spin–orbit coupling and inter-orbital spin fluctuations
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作者 Wei Wang Shun-Li Yu Jian-Xin Li 《Chinese Physics B》 2026年第2期247-256,共10页
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
关键词 kagome lattice CsCr_(3)Sb_(5) superconductivity spin–orbit coupling
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Enhancing energy storage of nickel-zinc battery through comprehensive d-p orbital hybridization regulation
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作者 Guochang Li Xiaokang Fu +5 位作者 Yifan Tang Shuangxing Cui Yuhui Wang Yitao Xu Yaoping Hu Lei Han 《Journal of Energy Chemistry》 2026年第1期945-954,I0020,共11页
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
关键词 P-NiMoO_(4)/NiSe_(2) Ni 3d-orbital Nickel-Zinc battery d-p orbital hybridization
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On-orbit refueling robust mission scheduling with uncertain duration for geosynchronous orbit spacecraft
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作者 Shuai YIN Chuanjiang LI +3 位作者 Edoardo FADDA Yanning GUO Guangtao RAN Paolo BRANDIMARTE 《Chinese Journal of Aeronautics》 2026年第1期410-424,共15页
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
关键词 Geosynchronous orbit(GEO) Hybrid Harris Hawks Optimization algorithm(HHHO) Mission scheduling On-orbit refueling Robust optimization
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基于UPLC-Q-Exactive Orbitrap MS技术的华山参化学成分分析
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作者 张玉茹 张红 +4 位作者 孟雪 崔小敏 张瑜 王娣 陈娟 《中华中医药杂志》 北大核心 2025年第6期3104-3110,共7页
目的:采用液质联用技术对华山参的化学成分进行快速鉴定与分析。方法:采用超高效液相色谱-静电场轨道阱高分辨质谱(UPLC-Q-Exactive Orbitrap MS)对华山参成分进行分析,采用Thermo Acclaim^(TM)RSLC 120 C_(18)色谱柱,以甲醇-0.1%甲酸... 目的:采用液质联用技术对华山参的化学成分进行快速鉴定与分析。方法:采用超高效液相色谱-静电场轨道阱高分辨质谱(UPLC-Q-Exactive Orbitrap MS)对华山参成分进行分析,采用Thermo Acclaim^(TM)RSLC 120 C_(18)色谱柱,以甲醇-0.1%甲酸水溶液为流动相进行梯度洗脱,流速0.3mL/min,柱温30℃。质谱分析采用正、负离子检测模式和电喷雾HESI离子源,扫描范围m/z80~1200。结果:从华山参中共鉴定出45个化学成分,其中,12个成分采用对照品进行比对。结论:本方法能系统、快速地对华山参中的化学成分进行识别,为华山参的物质基础研究、质量控制及资源开发提供科学依据。 展开更多
关键词 华山参 泡囊草属 托品烷类生物碱 轨道阱高分辨质谱 化学成分
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Spatial correlation singularities and orbital angular momentum spectra of partially coherent beams with noncanonical vortex pairs 被引量:1
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作者 MEI Chao CHENG Ke +2 位作者 YI Xiao-wen FU Cai-ying ZENG Ti-xian 《中国光学(中英文)》 北大核心 2025年第5期1243-1254,共12页
By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integra... By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integral. The effect of noncanonical strength, off-axis distance and vortex sign on spatial correlation singularities in far field is stressed. Furthermore, far-field OAM spectra and densities are also investigated, and the OAM detection and crosstalk probabilities are discussed. The results show that the number of dislocations of SCS always equals the sum of absolute values of topological charges for canonical or noncanonical vortex pairs. Although the sum of the product of each OAM mode and its power weight equals the algebraic sum of topological charges for canonical vortex pairs, the relationship no longer holds in the noncanonical case except for opposite-charge vortex pairs. The changes of off-axis distance, noncanonical strength or coherence length can lead to a more dominant power in adjacent mode than that in center detection mode, which also indicates that crosstalk probabilities of adjacent modes exceed the center detection probability. This work may provide potential applications in OAM-based optical communication, imaging, sensing and computing. 展开更多
关键词 spatial correlation singularity orbital angular momentum noncanonical vortex partially coherent beam
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Chinese satellite frequency and orbit entity relation extraction method based on dynamic integrated learning 被引量:2
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作者 Yuanzhi He Zhiqiang Li Zheng Dou 《Digital Communications and Networks》 2025年第3期787-794,共8页
Given the scarcity of Satellite Frequency and Orbit(SFO)resources,it holds paramount importance to establish a comprehensive knowledge graph of SFO field(SFO-KG)and employ knowledge reasoning technology to automatical... Given the scarcity of Satellite Frequency and Orbit(SFO)resources,it holds paramount importance to establish a comprehensive knowledge graph of SFO field(SFO-KG)and employ knowledge reasoning technology to automatically mine available SFO resources.An essential aspect of constructing SFO-KG is the extraction of Chinese entity relations.Unfortunately,there is currently no publicly available Chinese SFO entity Relation Extraction(RE)dataset.Moreover,publicly available SFO text data contain numerous NA(representing for“No Answer”)relation category sentences that resemble other relation sentences and pose challenges in accurate classification,resulting in low recall and precision for the NA relation category in entity RE.Consequently,this issue adversely affects both the accuracy of constructing the knowledge graph and the efficiency of RE processes.To address these challenges,this paper proposes a method for extracting Chinese SFO text entity relations based on dynamic integrated learning.This method includes the construction of a manually annotated Chinese SFO entity RE dataset and a classifier combining features of SFO resource data.The proposed approach combines integrated learning and pre-training models,specifically utilizing Bidirectional Encoder Representation from Transformers(BERT).In addition,it incorporates one-class classification,attention mechanisms,and dynamic feedback mechanisms to improve the performance of the RE model.Experimental results show that the proposed method outperforms the traditional methods in terms of F1 value when extracting entity relations from both balanced and long-tailed datasets. 展开更多
关键词 Knowledge graph Relation extraction One-class classification Satellite frequency and orbit resources BERT
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Impulsive thrust strategy for orbital pursuit-evasion games based on impulse-like constraint 被引量:1
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作者 Hongbo WANG Yao ZHANG +1 位作者 Hao LIU Kunpeng ZHANG 《Chinese Journal of Aeronautics》 2025年第1期520-536,共17页
This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the in... This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the interpretability of impulsive thrust strategy by integrating it within the framework of differential game in traditional continuous systems.First,this paper introduces an impulse-like constraint,with periodical changes in thrust amplitude,to characterize the impulsive thrust control.Then,the game with the impulse-like constraint is converted into the two-point boundary value problem,which is solved by the combined shooting and deep learning method proposed in this paper.Deep learning and numerical optimization are employed to obtain the guesses for unknown terminal adjoint variables and the game terminal time.Subsequently,the accurate values are solved by the shooting method to yield the optimal continuous thrust strategy with the impulse-like constraint.Finally,the shooting method is iteratively employed at each impulse decision moment to derive the impulsive thrust strategy guided by the optimal continuous thrust strategy.Numerical examples demonstrate the convergence of the combined shooting and deep learning method,even if the strongly nonlinear impulse-like constraint is introduced.The effect of the impulsive thrust strategy guided by the optimal continuous thrust strategy is also discussed. 展开更多
关键词 orbital pursuit-evasion game Differential game Impulsive thrust Deep learning Shooting method
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A model predictive Stackelberg solution to orbital pursuit-evasion game 被引量:1
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作者 Yuchen LIU Chaoyong LI +1 位作者 Jun JIANG Yonghe ZHANG 《Chinese Journal of Aeronautics》 2025年第2期244-255,共12页
In this paper,we investigate analytical numerical iterative strategies for the pursuit-evasion game involving spacecraft with leader–follower information.In the proposed problem,the interplay between two spacecraft g... In this paper,we investigate analytical numerical iterative strategies for the pursuit-evasion game involving spacecraft with leader–follower information.In the proposed problem,the interplay between two spacecraft gives rise to a dynamic and real-time game,complicated further by the presence of perturbation.The primary challenge lies in crafting control strategies that are both efficient and applicable to real-time game problems within a nonlinear system.To overcome this challenge,we introduce the model prediction and iterative correction technique proposed in model predictive static programming,enabling the generation of strategies in analytical iterative form for nonlinear systems.Subsequently,we proceed by integrating this model predictive framework into a simplified Stackelberg equilibrium formulation,tailored to address the practical complexities of leader–follower pursuit-evasion scenarios.Simulation results validate the effectiveness and exceptional efficiency of the proposed solution within a receding horizon framework. 展开更多
关键词 Model predictive control Pursuit-evasion problem Leader-follower game Stackelberg game orbital game
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Modulating d-d orbitals coupling in PtPdCu medium-entropy alloy aerogels to boost pH-general methanol electrooxidation performance 被引量:1
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作者 Kaili Wang Pengcheng Liu +7 位作者 Mingzhe Wang Tianran Wei Jitao Lu Xingling Zhao Zaiyong Jiang Zhimin Yuan Xijun Liu Jia He 《Chinese Chemical Letters》 2025年第4期221-228,共8页
Unraveling the essence of electronic structure effected by d-d orbital coupling of transition metal and methanol oxidation reaction(MOR)performance can fundamentally guide high efficient catalyst design.Herein,density... Unraveling the essence of electronic structure effected by d-d orbital coupling of transition metal and methanol oxidation reaction(MOR)performance can fundamentally guide high efficient catalyst design.Herein,density functional theory(DFT)calculations were performed at first to study the d–d orbital interaction of metallic Pt Pd Cu,revealing that the incorporation of Pd and Cu atoms into Pt system can enhance d-d electron interaction via capturing antibonding orbital electrons of Pt to fill the surrounding Pd and Cu atoms.Under the theoretical guidance,Pt Pd Cu medium entropy alloy aerogels(Pt Pd Cu MEAAs)catalysts have been designed and systematically screened for MOR under acid,alkaline and neutral electrolyte.Furthermore,DFT calculation and in-situ fourier transform infrared spectroscopy analysis indicate that Pt Pd Cu MEAAs follow the direct pathway via formate as the reactive intermediate to be directly oxidized to CO_(2).For practical direct methanol fuel cells(DMFCs),the Pt Pd Cu MEAAs-integrated ultra-thin catalyst layer(4–5μm thickness)as anode exhibits higher peak power density of 35 m W/cm^(2) than commercial Pt/C of 20 m W/cm^(2)(~40μm thickness)under the similar noble metal loading and an impressive stability retention at a 50-m A/cm^(2) constant current for 10 h.This work clearly proves that optimizing the intermediate adsorption capacity via d-d orbital coupling is an effective strategy to design highly efficient catalysts for DMFCs. 展开更多
关键词 Medium-entropy alloys aerogels d-d orbitals coupling pH-general Methanol oxidation reaction Ultra-thin catalyst layer
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Orbital ATK公司高轨在轨服务卫星功能分析及启示
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作者 王彪 宋旭民 +1 位作者 王伟林 王少成 《航天器工程》 北大核心 2025年第2期113-119,共7页
诺斯罗普·格鲁曼创新系统公司(Orbital ATK,Inc.现)是高轨在轨服务卫星领域的重要公司,其技术演进路径具有重要研究价值。首先系统梳理Orbital ATK公司在不同阶段研发的高轨在轨服务卫星体系。然后对比分析各卫星相关技术功能,得... 诺斯罗普·格鲁曼创新系统公司(Orbital ATK,Inc.现)是高轨在轨服务卫星领域的重要公司,其技术演进路径具有重要研究价值。首先系统梳理Orbital ATK公司在不同阶段研发的高轨在轨服务卫星体系。然后对比分析各卫星相关技术功能,得出“微卫星技术试验”(MiTEx)、“局部空间自动导航与制导试验”(ANGEL)、“地球同步轨道空间态势感知计划”(GSSAP)等卫星在星上导航和态势感知技术上的发展脉络;“ESPA增强静止轨道实验室实验平台”(EAGLE)与“持久推进ESPA”(LDPE)系列卫星通过应用运载火箭次级有效载荷适配器(ESPA)环平台创新了"主星+多载荷"的模块化架构,形成载荷快速迭代更新能力;“任务扩展飞行器”(MEV)则开创了航天器延寿服务新范式。最后总结Orbital ATK公司卫星发展过程,对未来高轨在轨服务卫星的发展提出了启示。 展开更多
关键词 高轨卫星 orbital ATK公司:在轨服务 功能特点
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