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Magneto‑Dielectric Synergy and Multiscale Hierarchical Structure Design Enable Flexible Multipurpose Microwave Absorption and Infrared Stealth Compatibility

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Nano-Micro Letters 2025年第2期17卷 401-416页

作者： Chen Li Leilei Liang Baoshan Zhang Yi Yang Guangbin Ji School of Electronic Science and Engineering Nanjing UniversityNanjing 210093People’s Republic of China College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR cloaking mechanisms and functional integration ***,we propose a multiscale hierarchical structure design,integrating wrinkled MXene IR shielding layer and flexible Fe_(3)O_(4)@C/PDMS microwave absorption *** top wrinkled MXene layer induces the intensive diffuse reflection effect,shielding IR radiation signals while allowing microwave to pass ***,the permeable microwaves are assimilated into the bottom Fe_(3)O_(4)@C/PDMS layer via strong magneto-electric *** theoretical and experimental optimization,the assembled stealth devices realize a near-perfect stealth capability in both X-band(8–12 GHz)and long-wave infrared(8–14μm)wavelength ***,it delivers a radar cross-section reduction of−20 dB m^(2),a large apparent temperature modulation range(ΔT=70℃),and a low average IR emissivity of ***,the optimal device demonstrates exceptional curved surface conformability,self-cleaning capability(contact angle≈129°),and abrasion resistance(recovery time≈5 s).This design strategy promotes the development of multispectral stealth technology and reinforces its applicability and durability in complex and hostile environments.

关键词： Microwave absorption Radar-infrared compatible stealth Wrinkled MXene Magneto-dielectric synergy Multifunction

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我国未来学习中心建设现状与路径探索

大学图书情报学刊 2025年第1期43卷 37-42,65页

作者：李小涛解玲南京航空航天大学图书馆 210016 南京航空航天大学经济与管理学院 210016

建设未来学习中心,是推进高等教育数字化转型和高校图书馆服务升级的有效途径。调研未来学习中心建设现状及存在问题,可为我国高等院校未来学习中心建设实践提供参考借鉴。文章运用文献调研和网络调查的方法,从顶层设计、建设理念、空... 详细信息

建设未来学习中心,是推进高等教育数字化转型和高校图书馆服务升级的有效途径。调研未来学习中心建设现状及存在问题,可为我国高等院校未来学习中心建设实践提供参考借鉴。文章运用文献调研和网络调查的方法,从顶层设计、建设理念、空间建设、资源建设、服务创新5个维度对全国高等院校未来学习中心建设实践进行调查,并对调查结果进行归类、统计和分析。研究发现,我国未来学习中心建设正处于起步探索期,在具体实践中存在着顶层设计不足、技术应用与教学模式融合不深等问题。针对这些问题,文章提出了相应的建设路径。

关键词：未来学习中心高校图书馆建设现状网络调研

OPERATIONAL MODAL ANALYSIS SCHEMES USING CORRELATION TECHNIQUE

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Acta Mechanica Solida Sinica 2005年第1期18卷 88-94页

作者： ZhengMin ShenFan ChenHuaihai CollegeofCivilAviation NanjingUniversityofAeronauticsandAstronauticsNanjing210016China InstituteofVibrationEngineeringResearch NanjingUniversityofAeronauticsandAstronauticsNanjing210016China

For some large-scale engineering structures in operating conditions, modal param- eters estimation must base itself on response-only data. This problem has received a considerable amount of attention in the past few years. It is well known that the cross-correlation function between the measured responses is a sum of complex exponential functions of the same form as the impulse response function of the original system. So this paper presents a time-domain operating modal identifcation global scheme and a frequency-domain scheme from output-only by cou- pling the cross-correlation function with conventional modal parameter estimation. The outlined techniques are applied to an airplane model to estimate modal parameters from response-only data.

关键词： modal analysis operating mode global identifcation cross-correlation

ON NONLINEAR STABILITY IN NONPARALLEL BOUNDARY LAYER FLOW

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Journal of Hydrodynamics 2004年第3期16卷 301-307页

作者： TANGDeng-bin WANGWei-zhi CollegeofAerospaceEngineering NanjingUniversityofAeronauticsandAstronauticsNanjing210016China

The nonlinear stability problem in nonparallel boundary layer flow fortwo-dimensional disturbances was studied by using a newly presented method called ParabolicStability Equations (PSE). A series of new modes generated by the nonlinear interaction ofdisturbance waves were tabu-lately analyzed, and the Mean Flow Distortion (MFD) was numericallygiven. The computational techniques developed, including the higher-order spectral method and themore effective algebraic mapping, increased greatly the numerical accuracy and the rate ofconvergence. With the predictor-corrector approach in the marching procedure, the normalizationcondition was satisfied, and the stability of numerical calculation could be ensured. With differentinitial amplitudes, the nonlinear stability of disturbance wave was studied. The results ofexamples show good agreement with the data given by the DNS using the full Navier-Stokes equations.

关键词： nonlinear stability boundary layer nonparallel flow parabolic stabilityequations (PSE) harmonic

PRINCIPAL PARAMETRIC AND THREE-TO-ONE INTERNAL RESONANCES OF FLEXIBLE BEAMS UNDERGOING A LARGE LINEAR MOTION

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Acta Mechanica Sinica 2003年第4期19卷 355-364页

作者：冯志华胡海岩 InstituteofVibrationEngineeringResearch NanjingUniversityofAeronauticsandAstronauticsNanjing210016China

A set of nonlinear differential equations is established by using Kane's method for the planar oscillation of flexible beams undergoing a large linear motion. In the case of a simply supported slender beam under certain average acceleration of base, the second natural frequency of the beam may approximate the tripled first one so that the condition of 3: i internal resonance of the beam holds true. The method of multiple scales is used to solve directly the nonlinear differential equations and to derive a set of nonlinear modulation equations for the principal parametric resonance of the first mode combined with 3: 1 internal resonance between the first two modes. Then, the modulation equations are numerically solved to obtain the steady-state response and the stability condition of the beam. The abundant nonlinear dynamic behaviors, such as various types of local bifurcations and chaos that do not appear for linear models, can be observed in the case studies. For a Hopf bifurcation,the 4-dimensional modulation equations are reduced onto the central manifold and the type of Hopf bifurcation is determined. As usual, a limit cycle may undergo a series of period-doubling bifurcations and become a chaotic oscillation at last.

关键词： flexible beam nonlinear dynamics method of multiple scales principal parametric resonance internal resonance

A Modified Mean Field Theory for Spin Systems with Orbital Degeneracy

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Chinese Physics Letters 2003年第5期20卷 735-737页

作者： SHIDa-Ning CollegeofScience NanjingUniveristyofAeronauticsandAstronauticsNanjing210016

In order to understand the ground state of spin systems with orbital degeneracy, we present a modified mean-field theory that includes four order parameters. Our mean-field results suggest that for a small Hund interaction, the flavour liquid state is still stable against the solid state, but long-range orders may be attained in the system with sufficient deviation from the SU(4) limit. Finally, the implications for the experimental observations on the system LaMnO3 are discussed.

关键词： LaMnO_3 锰酸镧旋转体系轨道退化修正均值域理论 Hund相互作用磁性

NUMERICAL SIMULATION OF TURBULENT SPOTS IN INCLINED OPEN-CHANNEL FLOW

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Journal of Hydrodynamics 2005年第2期17卷 179-185页

作者： ZHANGLi TANGDeng-bin CollegeofAerospaceEngineering NanjingUniversityofAeronauticsandAstronauticsNanjing210016China

The generation and evolution of turbulent spots in the open-channel flow are simulated numerically by using the Navier-Stokes equations. An effective numerical method with high accuracy and high resolution is developed. The fourth-order time splitting methods with high accuracy is proposed. Three-dimensional coupling difference methods are presented for the spatial discretization of the Poisson equation of pressure and Hemholtz equations of velocity, therefore, the fourth-order three-dimensional coupling central difference schemes are constituted. The fourth-order explicit upwind-biased compact difference schemes are designed to overcome the difficulty for the general higher-order central difference scheme which is inadaptable in the boundary neighborhood. The iterative algorithm and overall time marching is used to enhance efficiency. The method is applied in the numerical simulation of turbulent spots at various complex boundary conditions and flow domains. The generation and the developing process of turbulent spots are given, and the basic characteristics of turbulent spots are shown by simulating the evolution of the wall pulse in inclined open-channel flow.

关键词： turbulent spot Navier-Stokes equation numerical simulation three-dimensional coupling difference scheme wall pulse

Preparation of Nickel‑Cobalt/Carborundum Carbide Composite Coatings by Supergravity Field‑Enhanced Electrodeposition

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Chinese Journal of Mechanical Engineering 2020年第4期33卷 175-184页

作者： Xiaoyun Hu Ningsong Qu Nanjing University of Aeronautics and Astronautics Nanjing 210016China Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing 210016China

Nickel-cobalt/silicon carbide(Ni-Co/SiC)composite coatings were fabricated by supergravity field-enhanced *** surface morphology and the distribution of the SiC particles in the coatings were examined by scanning electron microscope and energy dispersive X-ray *** preferred orientations of the coatings were measured by X-ray *** wear resistance and microhardness were measured by a reciprocating tribometer and a microhardness instrument,*** results revealed that the use of the supergravity field enhanced the smoothness of the as-deposited Ni-Co/SiC coatings,and the SiC nanoparticles were uniformly distributed in comparison with that for conventional *** the rotation speed of the cathode,which provided the supergravity field,was 800 r/min,the SiC content in the coating reached a maximum of 8.1 wt%,which was a much higher content than the 2.2 wt%value obtained under conventional *** highest coating microhardness of 680 HV was also observed at this rotation *** addition,the wear resistance of the as-prepared Ni-Co/SiC coatings exhibited improved performance relative to that prepared under normal gravity.A minimum wear weight loss of 1.4 mg together with an average friction coefficient of 0.13 were also realized at a rotation speed of 800 r/min,values which were much lower than those for normal gravity.

关键词： Supergravity field Electrodeposition Microhardness Wear resistance

Electrochemical machining of a convex strips structure on a revolving part by using site directed power interruption

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Chinese Journal of Aeronautics 2018年第10期31卷 2049-2056页

作者： Yongcheng GE Zengwei ZHU Di ZHU Dengyong WANG Nanjing University of Aeronautics and Astronautics Nanjing 210016China Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing 210016China

Revolving parts with complex surface structures are widely used in machinery and mechanical equipment. The ECM process provides its adequacy to cut hard materials with different shapes, and its applications are widely increased, due to its outstanding advantages. In this paper, a new method for machining a convex strips structure on a cylinder by using site directed power interruption（SDPI） in the ECM process is presented. A variable correction value of the power-off time was defined and optimized to obtain the ideal interval for better machining accuracy and *** electric field distribution and the simulated convex profiles show that the stray current density can be reduced effectively by using the proposed method. The correction value has an important influence on the machining accuracy. A suitable correction value in the range of 0.6–1.2 s can effectively improve the machining accuracy of the convex strips structure. Experiments were also conducted to verify the proposed method. Results have confirmed that the stray corrosion on the convex strips surface is significantly reduced and the machining accuracy of convex strips structure is remarkably improved by using the proposed method with a suitable correction value in the ECM process. Finally, a convex strip with a height of 2 mm on a thin-wall revolving part was also produced successfully using a correction value of 0.9.

关键词： Convex strips structure Electrochemical machining Revolving part Site directed power interruption Stray corrosion