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Theoretical Calculations of HfSe_(3) Band Characteristics and Its Applications in Pulse Fiber Lasers

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Chinese Physics Letters 2025年第2期42卷 41-47页

作者： Weiwei Feng Ligang Chen institute of Airport Shandong University of AeronauticsBinzhou 256603China institute of Aeronautical Engineering Shandong University of AeronauticsBinzhou 256603China Shandong Engineering Research Center of Aeronautical Materials and Devices Binzhou 256603China

Transition metal trichalcogenides(TMTs)are known for their two-dimensional(2D)characteristics and the presence of quasi one-dimensional *** materials are less vulnerable to edge defects,which makes them suitable for optical and electronic devices with low-dimensional *** study demonstrates the application of HfSe_(3) nanomaterial as an emerging ultrafast photonic device capable of producing mode-locked and Q-switched pulses in fiber *** nonlinear optical absorption properties of a HfSe_(3)-based saturable absorber(SA)were analyzed,revealing a modulation depth of 7% and nonsaturable loss of 35%,*** addition,first principles-based theoretical calculations were performed to explore the optoelectronic properties of bulk HfSe_(3).The integration of the HfSe_(3)-based SA into an Er-doped fiber laser cavity enabled both Q-switched and mode-locked pulse *** the mode-locked operation,the pulse duration was 560 fs,accompanied by a signal-to-noise ratio(SNR)of 71.43 *** the Q-switched regime,the narrowest pulse width recorded was 757.1 ns with an SNR of 75.45 *** study indicates that nanodevices based on 2D TMTs hold promise for efficient ultrafast photonic applications and can be extensively employed in nonlinear optical technologies.

关键词： switched fiber absorber

Prediction of microstructure evolution of ZK61 alloy during hot spinning by internal state variable model

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 126-142页

作者： Jin-qi PAN Wen-cong ZHANG Jian-lei YANG Song-hui WANG Yong WU Huan LI School of Materials Science and Engineering Harbin Institute of Technology WeihaiWeihai 264209China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

An internal state variable(ISV)model was established according to the experimental results of hot plane strain compression(PSC)to predict the microstructure evolution during hot spinning of ZK61 *** effects of the internal variables were considered in this ISV model,and the parameters were optimized by genetic *** validation,the ISV model was used to simulate the evolution of grain size(GS)and dynamic recrystallization(DRX)fraction during hot spinning via Abaqus and its subroutine *** comparing the simulated results with the experimental results,the application of the ISV model was proven to be ***,the strength of the thin-walled spun ZK61 tube increased from 303 to 334 MPa due to grain refinement by DRX and texture ***,some ultrafine grains(0.5μm)that played an important role in mechanical properties were formed due to the proliferation,movement,and entanglement of dislocations during the spinning process.

关键词： internal state variable model hot spinning ZK61 alloy finite element simulation texture evolution

A single-pixel elemental imaging method using neutron-induced gamma-ray activation

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Nuclear Science and Techniques 2025年第1期36卷 1-12页

作者： Can Cheng Yong-Ji Xie Xun-Rong Xia Jia-Yu Gu Dong Zhao Yi-Ze Chen Ai-Yun Sun Xu-Wen Liang Wen-Bao Jia Da-Qian Hei Department of Ionizing Radiation and Medical Engineering Jiangsu Institute of MetrologyNanjing 210023China institute of Nuclear Analytical Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China China Nuclear Power Engineering Co. LtdBeijing 100840China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Neutron-induced gamma-ray imaging is a spectroscopic technique that uses characteristic gamma rays to infer the elemental distribution of an ***,this technique requires the use of large facilities to supply a high neutron flux and a time-consuming detection procedure involving direct collimating *** this study,a new method based on low neutron flux was proposed.A single-pixel gamma-ray detector combined with random pattern gamma-ray masks was used to measure the characteristic gamma rays emitted from the *** of the elemental distribution in the sample,comprising 30×30 pixels,were reconstructed using the maximum-likelihood expectation-maximization *** results demonstrate that the elemental imaging of the sample can be accurately determined using this *** proposed approach,which eliminates the need for high neutron flux and scanning measurements,can be used for in-field imaging applications.

关键词： Elemental imaging Neutron-induced gamma-ray activation Single-pixel imaging

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Targets capture by distributed active swarms via bio-inspired reinforcement learning

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 206-217页

作者： Kun Xu Yue Li Jun Sun Shuyuan Du Xinpeng Di Yuguang Yang Bo Li institute of Biomechanics and Medical Engineering Applied Mechanics LaboratoryDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Shanghai Aerospace Control Technology institute Shanghai 201109China Shanghai Key Laboratory of Aerospace Intelligent Control Technology Shanghai 201109China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Natural swarms arranged from cells to herds are usually decentralized but display intriguing collective intelligence in coordinating individuals across large scales to efficiently achieve their common *** from nature may provide new strategies for controlling collective dynamics of synthetic swarms to accomplish specific ***,we present a bioinspired computational framework that steers distributed active swarms to collectively capture and merge targets via reinforcement *** exploit collective milling structures of natural herds to cage the targets,and adopt a switching control policy inspired by sperms’chiral dynamics to optimize the trajectories of individuals,through which the active swarms can selforganize to enclose single or multiple distant targets in a dynamical,adaptive and scalable *** exists a critical swarm size,beyond which the excessive competition between agents would generate large mechanical forces,leading to capture instability but enabling the transition from short-distance to long-distance merging capture of multiple *** work provides physical insights into distributed active swarms and could offer a multilevel,decentralized strategy toward controlling swarm robotics in wide applications such as bio-medical devices,machine immunity,and target clearance.

关键词： swarm intelligence robotics multi-tasks artificial intelligence bionics

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Dynamic properties of low-density expandable polystyrene concrete materials

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Defence Technology(防务技术) 2025年第1期43卷 94-108页

作者： Jue Han Hualin Fan Army Engineering University of PLA Nanjing 210007China Research Center of Lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Aerospace StructuresNanjing University of Aeronautics and AstronauticsNanjing 210016China Henan International Joint Laboratory of Dynamics of Impact and Disaster of Engineering Structures Department of Civil EngineeringNanyang Institute of TechnologyNanyang 473004China

Expanded polystyrene(EPS)concrete,known for its environmental friendliness,energy absorption capacity,and low impedance,has significant potential application in the fields of wave absorption and vibration *** study designed and prepared EPS concrete materials with four levels of ***-static uniaxial compression and Split Hopkinson Pressure Bar(SHPB)impact tests were conducted to obtain stress-strain curves,elastic moduli,failure modes,energy absorptions,and strain rate effects of the EPS concrete under quasi-static and dynamic loading *** influences of density on various performance indicators were *** combining the Zhu-Wang-Tang(ZWT)constitutive model with a modified elastic-brittle model,a modified dynamic constitutive model was *** accuracy of the model was validated by the experimental *** results indicate that the addition of EPS particles enhances the ductility of the EPS *** EPS concrete has significant strain rate effect,which gets stronger as density *** modifiedconstitutive model accurately characterizes the dynamic stress-strain curves of the EPS concrete.

关键词： EPS concrete Impact behavior Constitutive model SHPB test

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Research on Transport Characteristics of the Gradient Structure Wick

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Frontiers in Heat and Mass Transfer 2025年第1期23卷 231-248页

作者： Shenghua Li Kehan Liu Bangxing Qian Ziwei Wen Bo Shi Lanzhou institute of Physics Lanzhou 730000 China College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Phase change heat transfer devices like heat pipes are widely utilized in temperature control and heat transfer. However, the traditional single uniform wick makes it hard to meet the requirements of capillary pressure and permeability for high-performance heat pipes, thus limiting the improvement of heat transfer performance. In this paper, a gradient structure wick sintered by 316 L stainless steel powder is designed. The capillary performance is tested and characterized through permeability test experiments and capillary rise infrared test experiments. Moreover, the influence of different particle sizes of sintered powder on the capillary performance of the wick structure is studied. The experimental results indicate that the capillary pressure and permeability of the gradient structure wick are significantly improved compared with the traditional single structure wick. Its capillary performance parameter S (K ⋅ ∆Pcap) is enhanced by more than 30%, providing an effective alternative for the wick of two-phase heat exchange devices.

关键词： Flat heat pipe gradient structure wick capillary performance permeability

Theoretical Calculations of HfSe3 Band Characteristics and Its Applications in Pulse Fiber Lasers

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Chinese Physics Letters 2025年第2期 39-45页

作者： Weiwei Feng Ligang Chen institute of Airport Shandong University of Aeronautics institute of Aeronautical Engineering Shandong University of Aeronautics Shandong Engineering Research Center of Aeronautical Materials and Devices

Transition metal trichalcogenides(TMTs) are known for their two-dimensional(2D) characteristics and the presence of quasi one-dimensional chains. These materials are less vulnerable to edge defects, which makes them s...

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Recent advances in photopolymerization 3D printing of alumina-ceramic

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Progress in Natural Science:Materials International 2025年第01期 1-30页

作者： M.Irfan Hussain Min Xia XiaoNa Ren Zhen Shen Muhammad Jamil Changchun Ge institute of Powder Metallurgy and Advanced Ceramics School of Material Science and Engineering University of Science and Technology Beijing State Key Laboratory of Multimodal Artificial Intelligence Systems Beijing Engineering Research Center of Intelligent Systems and Technology Institute of AutomationChinese Academy of Sciences College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

Digital light processing(DLP) 3D printing has a huge potential for manufacturing intricate and customized ceramic parts with high precision and cost-effectiveness. Research in this field contributes to material innovation,opening the avenues for new process designs in both scientific and industrial sectors. However, the implementation of DLP 3D printing technology in ceramic research has not yet reached the maturity level as that in polymer and tissue engineering. Necessarily, a holistic in-depth literature reporting the successful integration of alumina ceramics within DLP 3D printing technology is urgently needed. This review, systematic examines recent progress in DLP technology, focusing on photopolymer resins that incorporate UV-sensitive monomers, photoinitiators, and dispersants, as well as their synergistic effects on achieving high-quality printing, desirable material properties, and enhanced performance. Further, the review discusses key factors including post-processing characteristics such as debinding and sintering, which influence microstructure, and defect formation including microcracks, porosity and voids. Finally, the challenges associated with printing and sintering are highlighted,aiming to identify focused focused development pathways and potential solution to optimize outcomes. This analysis clarifies existing challenges and also propsoes future applications for DLP technology in the aluminaceramic field.

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High-precision trajectory tracking control of helicopter based on ant colony optimization-slime mould algorithm

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Chinese Journal of aeronautics 2025年第1期38卷 395-408页

作者： Binwu REN Siliang DU Zhuangzhuang CUI Yousong XU Qijun ZHAO National Key Laboratory of Helicopter Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China Faculty of Mechanical&Material Engineering HuaiYin Institute of TechnologyHuaian 223003China

To achieve high-precision trajectory following during helicopter maneuver tasks and reduce the disruptive influences of unknown variabilities,this study introduces a cascaded-loop helicopter trajectory tracking controller,whose parameters are set using an Ant Colony OptimizationSlime Mould Algorithm(ACO-SMA).Initially,a nonlinear flight dynamics model of the helicopter is *** gain functions and nonlinear feedback from a vibrational suppression function to improve the tracking performance of the controller,addressing issues in disturbance estimation and compensation of the Active Disturbance Rejection Control(ADRC).Simultaneously,a cascaded loop system,comprising an internal attitude loop and an external position loop,is created,and the ant colony-slime mold hybrid algorithm optimizes the system parameters of the trajectory tracking ***,helicopter trajectory tracking simulation experiments are conducted,including spiral ascending and“8”shape climbing *** findings indicate that the ADRC employed for helicopter trajectory tracking exhibits outstanding performance in rejecting disturbances caused by gusts and accurately tracking *** trajectory tracking controller,whose parameters are optimized by the ACO-SMA,shows higher tracking precision compared to the conventional PID and ADRC,thereby substantially improving the precision of maneuver tasks.

关键词： Flight control systems Helicopter ADRC Trajectory tracking ACO-SMA Spiral ascent "8"shape climbing