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Simplified K-linearization and dispersion compensation method for low-cost real-time serial sectioning-swept source optical coherence tomography 认领 引用 被引量：1
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作者 Wei Chen Lingxuan Meng +2 位作者 Xiuhua Zheng Shuaibin Chang Jianbo Tang 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2026年第3期82-89,共8页
Swept-Source Optical Coherence Tomography(SS-OCT)requires linear k-space sampling and dispersion compensation to achieve optimal axial resolution,typically necessitating expensive,high-speed data acquisition hardware.... Swept-Source Optical Coherence Tomography(SS-OCT)requires linear k-space sampling and dispersion compensation to achieve optimal axial resolution,typically necessitating expensive,high-speed data acquisition hardware.Existing numerical methods are computationally intensive,hindering real-time imaging.While phase linearization offers a simpler alternative,its applicability is limited to shallow depths.Here,we demonstrate that for serial sectioning and imaging,where the region of interest is confined to a few hundred micrometers,phase linearization is highly effective.We developed a simplified workflow that enables real-time reconstruction without added processing time.Using a commercial swept source,we maintained a sharp axial point spread function over a 700μm depth,sufficient for visualizing fine brain structures in mice.Our method allows for video-rate display using cost-effective,low-sampling-rate hardware. 展开更多
关键词 K-linearization dispersion compensation phase linearization
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Fixed-Structure Robust Feedback Linearization for Full Relative Degree Nonlinear Systems 认领 引用
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作者 Vlad Mihaly MirceaȘușcă Petru Dobra 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2025年第10期2026-2039,共14页
The exact feedback linearization method implies an accurate knowledge of the model and its parameters.This assumption is an inherent limitation of the method,suffering from robustness issues.In general,the model struc... The exact feedback linearization method implies an accurate knowledge of the model and its parameters.This assumption is an inherent limitation of the method,suffering from robustness issues.In general,the model structure is only partially known and its parameters present uncertainties.The current paper extends the classical exact feedback linearization to the robust feedback linearization by adding an appropriatelydesigned robust control layer.This is then able to ensure robust stability and robust performance for the given uncertain system in a desired region of attraction.We consider the case of full relative degree input-affine nonlinear systems,which are of great practical importance in the literature.The inner loop contains the feedback linearization input for the nominal system and the resulting residual nonlinearities can always be characterized as inverse additive uncertainties.The constructive proofs provide exact representations of the uncertainty models in three considered scenarios:unmatched,fully-matched,and partially-matched uncertainties.The uncertainty model will be a descriptor system,which also represents one of the novelties of the paper.Our approach leads to a simplified control structure and a less conservative coverage of the uncertainty set compared to current alternatives.The end-to-end procedure is emphasized on an illustrative example,in two different hypotheses. 展开更多
关键词 Feedback linearization nonlinear control robustness uncertain nonlinear systems
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Quality-guaranteed Dubins Path Planning for USV Based on Mixed-integer Piecewise linear Programming for Addressing the Extended Minimum-time Intercept Problem 认领 引用 被引量：1
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作者 Xing Zhou Kelin Zhu +3 位作者 Shuang Liu Zhaoqing Li Wenxin Zhang Kang Du 《哈尔滨工程大学学报（英文版）》 CSCD 2026年第1期216-227,共12页
During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive... During the use of robotics in applications such as antiterrorism or combat,a motion-constrained pursuer vehicle,such as a Dubins unmanned surface vehicle(USV),must get close enough(within a prescribed zero or positive distance)to a moving target as quickly as possible,resulting in the extended minimum-time intercept problem(EMTIP).Existing research has primarily focused on the zero-distance intercept problem,MTIP,establishing the necessary or sufficient conditions for MTIP optimality,and utilizing analytic algorithms,such as root-finding algorithms,to calculate the optimal solutions.However,these approaches depend heavily on the properties of the analytic algorithm,making them inapplicable when problem settings change,such as in the case of a positive effective range or complicated target motions outside uniform rectilinear motion.In this study,an approach employing a high-accuracy and quality-guaranteed mixed-integer piecewise-linear program(QG-PWL)is proposed for the EMTIP.This program can accommodate different effective interception ranges and complicated target motions(variable velocity or complicated trajectories).The high accuracy and quality guarantees of QG-PWL originate from elegant strategies such as piecewise linearization and other developed operation strategies.The approximate error in the intercept path length is proved to be bounded to h2/(4√2),where h is the piecewise length. 展开更多
关键词 Minimum-time intercept problem Dubins vehicle Mixed-integer piecewise-linear program Linearization Approximate error trigonometric function USV
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Sensitivity analysis of vibration characteristics and dynamic responses of a tracked vehicle 认领 引用 被引量：1
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作者 Xun Wang Xue Rui +3 位作者 Jinghong Wang Xiaoting Rui Guoping Wang Pingxin Wang 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2026年第3期323-348,共26页
This study aims to establish an integrated sensitivity analysis framework for optimization and design of the dynamic performance of mechanical systems such as tracked vehicles,by combining the direct differentiation m... This study aims to establish an integrated sensitivity analysis framework for optimization and design of the dynamic performance of mechanical systems such as tracked vehicles,by combining the direct differentiation method(DDM)with the linear multibody system transfer matrix method(linear MSTMM).The rigid-flexible coupled multibody system dynamics model of a tracked vehicle is established using the linear MSTMM and validated through the modal test.Building upon the existing DDM-based eigenvalue sensitivity analysis method within the linear MSTMM,the DDM is embedded into it to enable programmable and efficient computation of dynamic response sensitivities for mechanical systems.The proposed approach is used to quantitatively evaluate the sensitivities of both natural vibration characteristics(e.g.,natural frequencies and mode shapes)and transient dynamic responses of the tracked vehicle with respect to system parameters,successfully identifying critical structural parameters.Compared to conventional finite difference methods,the developed methodology eliminates sensitivity to perturbation step sizes.The contributions of this work lie in establishing a unified theoretical foundation and analysis framework for guiding dynamics optimization and design of mechanical systems,and extending the applicability of the linear MSTMM to sensitivity analysis of transient dynamic responses. 展开更多
关键词 Tracked vehicle Sensitivity analysis Vibration characteristics Dynamic responses Direct differentiation method Linear multibody system transfer matrix method
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A Continuous-Time Framework of Model-Free Adaptive Control for Nonlinear Plants 认领 引用
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作者 Hao Yu Wangjiang Li +2 位作者 Linxin Che Dawei Shi Zhongsheng Hou 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2026年第4期966-982,共17页
Continuous-time model-free adaptive control frameworks are proposed in this paper for solving tracking problems of unknown nonlinear plants described by high-order differential equations.To tackle situations where no ... Continuous-time model-free adaptive control frameworks are proposed in this paper for solving tracking problems of unknown nonlinear plants described by high-order differential equations.To tackle situations where no form or structural information of plant models is present,the first step involves introducing continuous-time dynamic linearization techniques to create data models.Based on different ways for generating control inputs,two kinds of dynamic linearization processes for continuous-time nonlinear plants are established for the first time,where the nonlinear plants are parameterized by a time-varying linear data model.In the first dynamic linearization model(DLM),the control input is calculated by designating its derivative while the second one gives directly control inputs.Then,after acquiring different dynamic linearization models,based on traditional backstepping methods,adaptive laws are proposed to learn the timevarying parameters in DLMs and the corresponding model-free adaptive controllers are designed.The conditions on designable parameters for the proposed controllers are provided to ensure semi-global practical stabilization and arbitrarily desirable ultimate tracking accuracy.Moreover,to eliminate the effects of unknown equilibrium points on tracking accuracy,a continuoustime model-free adaptive controller with pure integral terms is proposed under the second dynamic linearization model.Finally,several practical and numerical examples are simulated to illustrate the feasibility and efficiency of the proposed results. 展开更多
关键词 Backstepping methods continuous-time systems dynamic linearization model-free adaptive control (MFAC) nonlinear systems
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Tunable Redox-Active Anhydride-Based Linear Polymer as Organic Cathodes for Chemically Self-Charging Aqueous Zinc–Ion Batteries 认领 引用
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作者 Yan Wang Bin-He Wang +3 位作者 Lin Fan Mao-Bin Wei Qiong Wu Jing-Hai Yang 《Rare Metals》 SCIE EI CAS CSCD 2026年第3期771-783,共13页
Chemically self-charging aqueous zinc-ion batteries(AZIBs)have emerged as promising candidates for energy storage technologies owing to their environmental autonomy and structural simplicity.Nonetheless,the self-charg... Chemically self-charging aqueous zinc-ion batteries(AZIBs)have emerged as promising candidates for energy storage technologies owing to their environmental autonomy and structural simplicity.Nonetheless,the self-charging performance is significantly compromised by the limited potential difference between cathodes and oxygen,as well as the unsatisfactory cycling stability.Herein,we synthesized three novel polymeric cathodes(PM-E,NT-E,and PT-E)derived from distinct anhydride precursors for application in both AZIBs and chemical self-charging AZIBs.Combined experimental and density functional theory(DFT)analyses indicate that theπ-conjugated aromatic ring structures in various anhydride derivatives modulate the zinc storage activity of the carbonyl group(C=O).PT-E demonstrates superior electrochemical performance due to its optimal combination of band structure and molecular planarity,maintaining a specific capacity of 97.1 mAh g-1at 1 A g-1after 300cycles for AZIBs.Particularly,the PT-E cathode exhibits rechargeability through direct air oxidation without the external power supply;the discharged chemical self-charging AZIBs can be recharged to 1.28 V after exposure to air for 12 h.Meanwhile,it demonstrates excellent compatibility with combined chemical/galvanostatic charging environments,exhibiting exceptional electrochemical reversibility.This study advances chemical self-charging AZIBs technology while expanding the utilization scope of organic materials in autonomous energy storage systems. 展开更多
关键词 air-rechargeability anhydride aqueous zinc-ion batteries linear polymer organic cathodes
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Synergistic improvement of phytoremediation efficiency of arsenic-contaminated soil with Sedum lineare by phosphate-solubilizing strain P-1 and 2,4-epibrassinolide 认领 引用
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作者 Shaohui Yang Ying Chu +3 位作者 Ziyi Liu Chuhan Zhang Yang Yu Jiehua Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第6期394-406,共13页
Phytoremediation of arsenic(As)-contaminated soils is often hindered by As toxicity,low bioavailability,and the limited growth rate and biomass of remediator plants.To address this,we investigated the synergistic effe... Phytoremediation of arsenic(As)-contaminated soils is often hindered by As toxicity,low bioavailability,and the limited growth rate and biomass of remediator plants.To address this,we investigated the synergistic effects of 24-epibrassinolide(EBR)and the phosphate-solubilizing strain P-1 on enhancing As phytoremediation efficiency using Sedum lineare—a stress-tolerant species.Our results demonstrated that both individual and combined applications significantly improved S.lineare’s physiological performance,alleviating As-induced growth inhibition.The EBR+P-1 co-treatment exhibited the strongest effects,increasing biomasses(shoot and root dry weight by 66.7%and 62.5%,respectively)and total As accumulation(97.3%)compared to the control.This treatment also enhanced antioxidant enzyme activities(superoxide dismutase and catalase),reduced oxidative stress markers(reactive oxygen species and malondialdehyde),and decreased bioavailable As in soil.Partial Least Squares Path Modeling identified antioxidant defense and nutrient uptake as key drivers of As tolerance.Crucially,EBR application uniquely restructured the rhizosphere microbiome,enriching stress-tolerant(Flavobacterium)and metalmobilizing taxa(Patescibacteria),which correlated with improved soil enzyme activities(alkaline phosphatase,sucrase)and contributed significantly to plant resilience and As mobilization.These findings demonstrate that the combined use of EBR and strain P-1,leveraging novel microbiome engineering,offers a highly effective strategy for enhancing S.lineare-based As phytoremediation.It provides a practical approach for the sustainable remediation of moderately to heavily As-contaminated soils,especially in mining-affected or industrial wasteland areas. 展开更多
关键词 Phytoremediation Arsenic(As) Sedum lineare Phosphate-solubilizing bacteria(P-1) 2,4-epibrassinolide(EBR) Rhizosphere microbiome
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Prediction method for stationary crossflow instability transition in supersonic boundary layers based on multi-layer perceptron 认领 引用
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作者 Lei Qiao Xi Jiang +5 位作者 Jiakun Fan Yutian Wang Lu Xie Ningjuan Dong Jiakuan Xu Junqiang Bai 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第7期36-51,共16页
Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory ... Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory predictive capabilities for this kind of transition,its practical implementation faces inherent limitations:the requirement of first-and second-order wallnormal derivatives of boundary layer velocityemperature profiles,the need for initial eigenvalue guesses,and the computational burden of solving eigenvalue problems.To address these challenges,this study develops a multi-layer perceptron(MLP)model tailored for linear stability analysis of three-dimensional compressible boundary layers based on the artificially defined quasi-three-dimensional non-similar boundary layer solutions.The boundary layer edge flow parameters and perturbation characteristics are mapped to eigenvalues or local growth rates of the envelop curves through fully connected layers.This architecture eliminates the need for computing wall-normal derivatives of velocityemperature profiles,initial eigenvalue estimation,and direct eigenvalue problem solving.Extensive validation across varying operational conditions and geometries(airfoils and swept wings)demonstrates exceptional agreement between the MLP’s predictions(eigenvalues and disturbance amplification factors)and traditional LST results.Furthermore,the model’s transition prediction capability is rigorously verified using National Aeronautics and Space Administration’s supersonic swept-wing crossflow-dominated transition benchmark,incorporating both stability analysis and flight test data.Results confirm the model is an efficient and reliable computational framework for transition prediction in three-dimensional finite-span wings. 展开更多
关键词 Supersonic swept wing Boundary layer transition Crossflow instability Linear stability theory eN method Multi-layer perceptron
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Subseasonal Prediction of April Siberian-Arctic Heatwaves Using a Dynamical-Statistical Approach 认领 引用
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作者 Yan XIA Fei XIE +4 位作者 Jianping LI Yongyun HU Yi HUANG Jianchun BIAN Chuanfeng ZHAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2026年第5期907-918,共12页
Siberian-Arctic heatwaves(SAHs)disrupt ecosystems by increasing wildfires,thawing permafrost,and threatening Arctic communities.As SAHs become more frequent and intense,accurate prediction is crucial for preparedness ... Siberian-Arctic heatwaves(SAHs)disrupt ecosystems by increasing wildfires,thawing permafrost,and threatening Arctic communities.As SAHs become more frequent and intense,accurate prediction is crucial for preparedness and mitigating their impacts.We demonstrate that April surface temperatures in the Siberian Arctic can be predicted one month in advance with a skill of 0.75(1979-2022)using a regression model based on Arctic stratospheric ozone,the Arctic Oscillation,and sea ice in the Kara Sea.This model successfully predicts six of seven SAHs,identifying three driven by extreme ozone depletion and three by significant sea-ice loss.Additionally,from 1979 to 1997,warming was primarily caused by ozone depletion,while from 1998 to 2022,sea-ice loss became the main factor.Our findings indicate that SAHs are predictable and recommend this model for real-time monitoring and forecasting,highlighting its potential to enhance preparedness and reduce adverse effects. 展开更多
关键词 subseasonal prediction Siberian-Arctic heatwaves stratospheric Arctic ozone sea ice multiple linear regression
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Open-loop control of combustion instabilities in a full-scale annular ramjet combustor using linear genetic programming 认领 引用
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作者 Jianguo TAN Zheng XU +2 位作者 Yao LIU Dongdong ZHANG Yi HOU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第2期20-28,共9页
The operational demands of a wide range significantly exacerbate combustion instability issues within ramjet combustor.To suppress combustion oscillations,an open-loop control system utilizing Linear Genetic Programmi... The operational demands of a wide range significantly exacerbate combustion instability issues within ramjet combustor.To suppress combustion oscillations,an open-loop control system utilizing Linear Genetic Programming(LGP)has been developed for a full-scale annular ramjet combustor.The LGP is used to generate control laws that include multi-frequency forcing.These laws are then transformed into square waves to actuate the solenoid valve,which modulates the kerosene supply for open-loop control.The results show that the duty cycle has little effect on instability amplitude,whereas an increase in frequency leads to a remarked reduction in combustion amplitude.After five generations evolvements,the pressure amplitude is reduced by 40.6% under the optimal control law generated by LGP.Furthermore,the machine learning process is depicted using a proximity map of control law similarity,with the search pathway visualized by the steepest descent.All individuals go forward to the upper left corner of the map with the evolution process,terminating at the optimal individual of the fifth generation. 展开更多
关键词 Annular ramjet combustor Combustion instabilities Linear genetic programming Machine learning Open-loop control
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Robust self-triggered switching control of autonomous ground vehicles with varying linear parameters 认领 引用
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作者 Yuanlong XIE Shuting WANG +3 位作者 Liquan JIANG Hu LI Hao WU Sheng-quan XIE 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2026年第5期453-465,I0001-I0007,共13页
We propose a robust self-triggered switching control scheme for four-wheel-steering autonomous ground vehicles(FAGVs)to enhance tracking precision in the face of significant parameter variations.First,using the polyto... We propose a robust self-triggered switching control scheme for four-wheel-steering autonomous ground vehicles(FAGVs)to enhance tracking precision in the face of significant parameter variations.First,using the polytopic mechanism,the nonlinear dynamics of an FAGV are formulated as a switched linear parameter-varying system to accommodate parametric perturbations.With suitable dwell time,a novel self-triggered switching law is designed using energy density in terms of the tracking accuracy and system robustness;this satisfies the required control criteria while also preventing the Zeno phenomenon caused by traditional high-frequency switching.Through the application of multiple parameter-correlated Lyapunov functions,the resultant closed-loop system is ensured to be asymptotically stable with suitable auto-tuned gains.Finally,the efficacy and superiority of the proposed method are verified through experiments with an FAGV system. 展开更多
关键词 Varying linear parameters Autonomous ground vehicle Switching controller Zeno avoidance Robust control
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Experimental study on damage characteristics of t-shaped stiffened plates subjected to different types of shaped charges:Linear-shaped charge,embowed linear-shaped charge,and embowed linear explosively formed projectile 认领 引用
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作者 Shenhe Zhang Zhifan Zhang +4 位作者 Shuxin Yang Longkan Wang Yutong Sui Guiyong Zhang Zhi Zong 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2026年第2期231-243,共13页
In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-f... In order to investigate the penetration performance of Linear-Shaped Charge(LSC),Embowed LinearShaped Charge(ELSC),and Embowed Linear Explosively Formed Projectile(ELEFP)on T-shaped stiffened plates,a series of near-field air-burst experiments are conducted.The damage modes and characteristics of the target plates are compared and analyzed.Each flat plate section is completely punctured,resulting in a penetration hole.The damage modes induced by the three charge types on the stiffened plate structure are consistent,characterized by shear failure in the central region of the flat plate due to penetration by the penetrator,localized plastic deformation of the flat plate,and local penetration failure resulting from partial perforation of the central stiffener.The penetration lengths caused by ELSC and ELEFP are 45.1%and 46.1% larger than that of LSC,while the half-width of the penetration hole generated by ELEFP is 54.2% and 24.7% smaller than that of ELSC and LSC,respectively.The penetration height caused by ELEFP are 17.5%and 62.1% larger than that of ELSC and LSC,respectively.The stiffener effectively segments the damage area,enhancing the local structural strength and limiting the extent of plastic deformation in the flat plate section.The comparative results show that the ELSC proves to be more effective for efficient large-scale damage,and ELEFP is more suitable for achieving efficient localized damage. 展开更多
关键词 Linear-shaped charge Embowed linear-shaped charge Embowed linear explosively formed projectile Near-filed explosion Penetration performance Stiffened plate
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Effect of loading rate on the brittleness index of granite:An experimental investigation 认领 引用
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作者 YIN Tu-bing LIU Fan +4 位作者 MA Jie-xin DAI Hao LU Jian-fei GUO Wen-xuan LI Xi-bing 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第4期1728-1745,共18页
In deep underground engineering,rock brittleness is closely associated with rockburst and feasibility of hydraulic fracturing.The loading rate plays a crucial role in determining the severity of rockburst and cuttabil... In deep underground engineering,rock brittleness is closely associated with rockburst and feasibility of hydraulic fracturing.The loading rate plays a crucial role in determining the severity of rockburst and cuttability.By conducting uniaxial compression tests and single-cycle loading-unloading experiments,the brittle evolution of four types of granite under different loading rates was investigated.During the uniaxial compression process,acoustic emission parameters were used to characterize the crack evolution patterns.Additionally,the macroscopic failure process of the specimens and the post-failure rock fragments were recorded with a high-speed camera,providing multi-scale validation.This study proposes a quantitative brittleness index based on rock fracture energy,and its validity is verified by analyzing the rock failure process and the macroscopic characteristics of rock fragments.:This work contributes to advancing research on rock brittleness indices considering the coupling between energy evolution and kinematic mechanisms.The research results indicate that as the loading rate increases from 0.1 mm/min to 5 mm/min,the quantitative evaluation index(Bs)for brittleness increases from 0.17 to 0.28,while the qualitative evaluation indices MF(projectile mass ratio)and l(average lumpiness)increase from 0.3261 to 0.4184 and from 32.96 mm to 38.12 mm,respectively.With increasing loading rates,the brittleness of the rock increases significantly.A series of qualitative and quantitative results,including fractal characteristics and acoustic emission parameters,reveal the crack evolution patterns of granite under different loading rates and confirm the rationality of the brittleness index.This study provides theoretical guidance for practical deep underground engineering applications. 展开更多
关键词 linear energy storage law brittleness index fracture mechanism projectile mass ratio average lumpiness
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Neural Network Based Feedback Linearization Control of an Unmanned Aerial Vehicle 认领 引用 被引量：3
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作者 Dan Necsulescu Yi-Wu Jiang Bumsoo Kim 《International Journal of Automation and computing》 2007年第1期71-79,共9页
This paper presents a flight control design for an unmanned aerial vehicle （UAV） using a nonlinear autoregressive moving average （NARMA-L2） neural network based feedback linearization and output redefinition techn... This paper presents a flight control design for an unmanned aerial vehicle （UAV） using a nonlinear autoregressive moving average （NARMA-L2） neural network based feedback linearization and output redefinition technique. The UAV investigated is non- minimum phase. The output redefinition technique is used in such a way that the resulting system to be inverted is a minimum phase system. The NARMA-L2 neural network is trained off-line for forward dynamics of the UAV model with redefined output and is then inverted to force the real output to approximately track a command input. Simulation results show that the proposed approaches have good performance. 展开更多
关键词 Nonlinear unmanned aerial vehicle （UAV） flight control non-minimum phase output redefinition neural network basedfeedback linearization.
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Design and commissioning of a multiharmonic bunching system for the high‑intensity heavy‑ion accelerator facility 认领 引用
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作者 Zheng‑Rong Wu Long‑Bo Shi +7 位作者 Zheng‑Long Zhu Ke‑An Jin Guo‑Dong Jiang Zhen Gao Feng Qiu Yao Yang Gui‑Rong Huang Lie‑Peng Sun 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第8期68-81,共14页
The high-intensity heavy ion accelerator facility(HIAF)is currently under construction in China for multidiscipline research.The front-end section has been completed and is currently undergoing commissioning.To optimi... The high-intensity heavy ion accelerator facility(HIAF)is currently under construction in China for multidiscipline research.The front-end section has been completed and is currently undergoing commissioning.To optimize beam quality,an external multiharmonic buncher(MHB)that reduces longitudinal emittance has been installed before the radio frequency quadrupole.The MHB system includes both cavity and low-level radio frequency(LLRF)system designs.The cavity consists of a quarter-wave resonator and a half-wave resonator,with a single grid-less gap,capable of providing the required voltage of 1.5 kV.With the newly developed multiharmonic LLRF control system,precise individual control of the four-harmonic components can be achieved,enabling flexible synthesis of various waveform configurations.The buncher can generate a 1st+2nd+3rd+4th harmonic bunching electric field with a fundamental frequency of 40.625 MHz,or a 1st+2nd harmonic bunching electric field with a fundamental frequency of 81.25 MHz.In addition,the first O6+beam commissioning results of front-end accelerator are presented herein,providing insights into the contribution of the MHB. 展开更多
关键词 Heavy-ion Buncher Linear accelerator Multiharmonic signal
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Linear relationship between reactivity and the reciprocal of uranium concentration in thermal‑spectrum molten salt reactors 认领 引用
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作者 Chang-Qing Yu Gui-Feng Zhu +7 位作者 Shu-Yang Jia Yang Zou Rui Yan Jian Guo Ya-Fen Liu Bo Zhou Xue-Chao Zhao Xiao-Han Yu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第2期208-222,共15页
Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain... Knowing the precise relationship between fuel loading and reactivity is essential for guiding reactor criticality extrapolation and online refueling in molten salt reactors(MSRs).This study aims to explore and explain the linear relationship between reactivity and the reciprocal of uranium concentration in thermal-spectrum MSRs.By applying neutron balance theory,we analyzed the neutron absorption cross sections of various nuclides in single-lattice models with varying fuel concentrations.Our findings reveal a simple linear correlation between reactivity and the reciprocal of uranium concentration,which can be explained from the perspective of nuclear reaction cross sections that adhere to the 1/v law in the thermal neutron spectrum.Furthermore,we identified that the neutron absorption single-group cross sections of structural materials and carrier salts exhibit an approximately linear relationship with the fission single-group cross section of 235 U;similarly,the reciprocal of 235U’s fission cross section exhibits an approximately linear relationship with uranium concentration.This linear relationship deviates as the volume fraction of molten salt increases,due to a greater proportion of neutrons being captured in the resonance energy spectrum.However,it remains valid for molten salt volume fractions up to 25%and demonstrates broad applicability in the physical design and operation of thermal molten salt reactors. 展开更多
关键词 Molten salt reactor Reactivity Uranium concentration Cross sections Linear
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Robust connectivity in time-frequency dual fading channels for the 6G satellite IoT:chirp and FRFT 认领 引用
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作者 Wenliang Lin Xinghao Cao +6 位作者 Ke Wang Zhongliang Deng Yishan He Kejia Cui Yaohua Deng Da Wan Zhiwei He 《Digital Communications and Networks》 SCIE EI CSCD 2026年第2期375-387,共13页
With the development of Sixth-Generation(6G)mobile communication technologies,Low Earth Orbit(LEO)satellite communication systems have become extremely important in mobile communications owing to their large coverage,... With the development of Sixth-Generation(6G)mobile communication technologies,Low Earth Orbit(LEO)satellite communication systems have become extremely important in mobile communications owing to their large coverage,high efficiency,and low cost.However,the high dynamic LEO satellite channels cause serious time-frequency dual selective fading,significantly impairing the performance of conventional single time or frequency domain synchronization algorithms and limiting their applicability.To address these challenges,this paper proposes a synchronization algorithm based on Linear Frequency Modulation(LFM)signals and the Fractional Fourier Transform(FRFT).Exploiting the inherent robustness of LFM signals against frequency deviations and multipath effects,coupled with their energy concentration property in the optimal fractional Fourier domain,the proposed algorithm enables efficient synchronization with enhanced resilience to time-frequency variations.Furthermore,LFM preamble sequences are optimally designed for diverse channel conditions.This work presents a theoretical analysis of the time-frequency nonstationary characteristics of LEO satellite channels and discusses the performance limitations of traditional synchronization algorithms.The proposed integrated FRFTLFM synchronization framework and sequence optimization scheme are rigorously evaluated via comprehensive simulations.The results demonstrate substantial improvements in synchronization accuracy and computational efficiency compared with conventional methods,particularly under time-frequency dual selective fading LEO satellite channels.The algorithm provides a robust and reliable solution for time-frequency synchronization in LEO satellite communication systems,thereby enhancing overall system performance and reliability. 展开更多
关键词 Time-frequency synchronization Linear frequency modulation Fractional fourier transform Low earth orbit satellite communications Nonstationary channel
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Progress in local-variable-based transition-turbulence models for subsonic and transonic boundary layers 认领 引用
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作者 Jiakuan XU Xi JIANG +3 位作者 Yutian WANG Ningjuan DONG Lei QIAO Junqiang BAI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第4期26-53,共28页
The accurate prediction of boundary layer transition represents a persistent and extensively studied challenge in fluid mechanics and aircraft aerodynamic design.It is well recognized that,due to the limitations in co... The accurate prediction of boundary layer transition represents a persistent and extensively studied challenge in fluid mechanics and aircraft aerodynamic design.It is well recognized that,due to the limitations in computational efficiency and shape complexity,high-resolution numerical simulation techniques and classical stability theory are hard to be applied in the numerical simulation and optimization of complex aircraft designs.The classical correlation-based Langtry and Menter model and laminar kinetic energy model,incorporating stability analysis results,offer efficient solution strategies under the Reynolds-averaged Navier-Stokes framework.Nonetheless,these models rely heavily on the range of available experimental data,which significantly restricts their applicability.Therefore,the Amplification Factor Transport(AFT)transition model anchored in linear stability theory foundations was derived from the findings of Coder and Maughmer and has since been adopted for transition prediction across a variety of complex geometries.This model not only incorporates the analytical foundation of linear stability theory,but also predicts the maximum envelope N value through a transport equation.It enables all non-local variables to be solved locally,ensuring compatibility with massively parallel computational fluid dynamics solvers.This paper systematically introduces the modeling concepts and key variable solution strategies of the currently prevalent transition-turbulence models based on local variables.It emphasizes the evolution of AFT transition frameworks,highlighting their progression from applications in the transition from 2D to 3D compressible boundary layer Tollmien-Schlichting waves,together with the formation of stationary crossflow vortices.In conclusion,this paper addresses the remaining challenges of the amplification factor transport transition model and explores potential directions for its future development. 展开更多
关键词 Boundary layer transition Computational fluid dynamics Linear stability theory Local variable Transition-turbulence model
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Short-period dense linear array ambient noise tomography of shallow crustal structure across the Haichenghe fault zone,China 认领 引用
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作者 Mingruo Jiao Liang Wang +9 位作者 Hongyu Ni Haiyan Wang Lanshu Bai Shuo Liu Zhihong Zhang Zhenpeng Yang Zhengdong Cui Qingshan Sun Rui Qian Mengying Li 《Earthquake Science》 CAS CSCD 2026年第2期220-234,共15页
The Haicheng region,Liaoning,China,likely hosts a conjugate fault system comprising the NW-trending Haichenghe fault and NE-trending secondary faults.On February 4,1975,at 19:36 CST,an earthquake of MS7.3 and inten... The Haicheng region,Liaoning,China,likely hosts a conjugate fault system comprising the NW-trending Haichenghe fault and NE-trending secondary faults.On February 4,1975,at 19:36 CST,an earthquake of MS7.3 and intensity(MMI)IX hit the city of Haicheng,Liaoning,China.Although deep seismic profiling was previously conducted along the Haichenghe fault,the limited horizontal resolution in the shallow part prevented the recognition of kilometer-scale anomalies.The velocity structure characteristics of the Haichenghe fault and its NE-trending conjugate faults remain unclear.Using the extended range phase shift method,the high-resolution S-wave velocity structures are obtained by deploying a long,dense linear array of 55 short-period seismometers across the fault and NE-trending conjugate faults.The array length was 32 km and inter-station spacing was approximately 600 m,facilitating the collection of approximately 22 days of continuous waveform data.Employing the Extended Range Phase Shift(ERPS)method enabled the extraction of broadband 0.2–5 s Rayleigh wave phase velocity dispersion curves.The broadband dispersion data were used for inversion of the high-resolution S-wave velocity structure to a depth of 8 km from the surface.The velocity structure characteristics and seismicity of the Haichenghe fault and NE-trending conjugate faults were analyzed and compared with nearby fault gas measurements.Results show(1)shallow S-wave velocities show a low-high-low horizontal distribution,corresponding to basin-uplift-basin topography;(2)significant velocity contrasts occur across the Haichenghe fault:its SW segment(0–17 km)exhibits high velocities consistent with Paleoproterozoic crystalline basement(Pt1),while the NE segment(17–32 km)shows low velocities related to Yanshanian intrusions(γ5)and Quaternary sediments.NE-trending conjugate faults display sharp velocity gradients marking fracture locations,with all faults being near-vertical to~8 km depth;(3)seismicity at 1–6 km depth mainly clusters in high-velocity zones;at 6–8 km depth,it concentrates beneath the Haichenghe fault in low-velocity areas and along NE-trending faults;(4)the seismic activity characteristics and fault zone width of the Haicheng he fault reflected by velocity imaging results are basically consistent with those obtained by the fault gas measurement method. 展开更多
关键词 dense linear array ambient noise tomography extended range phase shift method S-wave velocity structure Haichenghe fault
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State Estimation With Model Uncertainty Using Structure Variational Bayesian and Transfer Learning 认领 引用
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作者 Shuang Gao Xiaoli Luan +2 位作者 Biao Huang Shunyi Zhao Fei Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2026年第3期715-727,共13页
This paper proposes a novel approach to address parameter uncertainties for state estimation in Markovian jump linear systems by leveraging transfer learning.Assume that the source domain model is available and reliab... This paper proposes a novel approach to address parameter uncertainties for state estimation in Markovian jump linear systems by leveraging transfer learning.Assume that the source domain model is available and reliable,and the target domain model has significant model parameter uncertainties.To enhance estimation performance in the target domain,the proposed method transfers model knowledge from the source domain and adjusts it using a tuning factor before incorporating it into the target domain estimator.More specifically,this approach involves transferring the modified probability density functions of state prediction from the source domain to the target domain and determining the tuning factor via structure variational Bayesian inference using measurements in the target domain.Using numerical examples and a 1-DOF torsion system,we showcase the competitiveness of the proposed state estimator compared to the existing robust state estimation methods when dealing with parameter uncertainties.The results highlight its capability to improve estimation accuracy in practical scenarios,showcasing its potential for real-world applications. 展开更多
关键词 Markovian jump linear systems parameter uncertainty state estimation structure variational inference transfer learning
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