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A Novel Full-Band Microwave Absorber Based on Scattering Enhanced Prism-Honeycomb nested structure

ADVANCED FUNCTIONAL MATERIALS 2025年第0期

作者： Liu, Shaokang Zhou, Yanming Zhang, Fangxin Wang, Qingshan Zhao, Xing Chao, Bin Wu, Haihua Cent South Univ Coll Mech & Elect Engn Changsha 410083 Peoples R China Cent South Univ State Key Lab High Performance Complex Mfg Changsha 410083 Peoples R China China Three Gorges Univ Coll Mech & Power Engn Yichang 443002 Peoples R China Cent South Univ Inst Light Alloy Changsha 410083 Peoples R China

With advancements in radar detection technology, electromagnetic stealth has garnered significant attention in military applications. Traditional electromagnetic absorbers typically focus on tuning electromagnetic parameters;however, they are often limited by material constraints, resulting in effective absorption only within narrow frequency bands. This work presents a novel prism-honeycomb nested microwave absorbing structure, inspired by the scattering phenomenon of light waves in a prism, which utilizes an enhanced scattering effect. The varying impedances of electromagnetic waves (EMWs) in different media lead to transmission and reflection that adhere to Snell's law at the interfaces. To optimize the scattering effect, the inner prism is filled with a high transmittance material, while the outer honeycomb structure incorporates a material with high dielectric loss. Consequently, electromagnetic waves experience significant attenuation within the unit. Despite a thickness of only 7 mm, this structure achieves over 90% EMW absorption across a broad frequency range of 1-18 GHz. Additionally, the honeycomb structure exhibits excellent mechanical load-bearing capacity. The nesting of the prism further enhances support points, resulting in a compressive strength of 16.4 MPa. This innovative design not only facilitates full-band absorption but also provides high mechanical load-bearing capabilities, offering valuable insights for applications in electromagnetic stealth and camouflage.

关键词： magneto electric composite microwave absorption nested structure Ni scattering prism

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nested-structure ZrO2-MoSi2-SiC High-Emissivity Coating on the Flexible Fiber Fabric with Enhanced Bonding Strength and Thermal Insulation Performance

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ACS APPLIED MATERIALS & INTERFACES 2025年第14期17卷 21785-21795页

作者： Liang, Zhijie Zhang, Xueying Ma, Xiaohui Liu, Mengjie Du, Haiyan Yan, Liwen Guo, Anran Hou, Feng Liu, Jiachen Tianjin Univ Sch Mat Sci & Engn Key Lab Adv Ceram & Machining Technol Minist Educ Tianjin 300072 Peoples R China

Research on high-emissivity coatings for flexible thermal insulation felts used in aerospace vehicles has achieved substantial progress. However, the bonding strength of these systems remains a critical challenge that necessitates further improvement. Herein, a nested-structure high-emissivity coating, comprising a Zr precursor-based shell integrated with an Al2O3-MoSi2-SiC (AMS) layer, is applied on alumina fiber fabric (AFF). The nested-structure Zr precursor-based shell not only improves interfacial properties through structural design but also effectively enhances thermal insulation by facilitating multiple reflections and absorptions of infrared radiation. The Zr precursor shell penetrates into the interior of the fiber fabric, providing direct thermal protection to the fiber matrix. Simultaneously, at high temperatures, it reacts with the surface high-emissivity coating to form a ZrSiO4-modified mechanical interlocking structure, thereby significantly enhancing the bonding strength. The bonding strength between the nested-structure precursor composite coating (NPCC) and the AFF substrate was measured to be 0.34 MPa at 1300 degrees C, showing an 80% enhancement compared to that of the single-layer AMS coating. Upon continuous heating at 1445 degrees C for 10 min using a butane torch, the temperature on the backside of the NPCC-coated AFF remained relatively stable at 212 degrees C, which is notably decreased by 50 degrees C compared to that of the single-layer AMS-coated AFF. In the wavelength range of 3-8 mu m, the average emissivity of the coating was 0.91. The NPCC significantly enhances both the bonding strength and thermal insulation performance of AFF, offering promising prospects for applications in thermal protection systems.

关键词： nested structure high-emissivity coating bonding strength thermal insulation alumina fiberfabric

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nested structure in parameterized rough reduction

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INFORMATION SCIENCES 2013年 248卷 130-150页

作者： Zhao, Suyun Wang, Xizhao Chen, Degang Tsang, Eric C. C. Renmin Univ China MOE Key Lab Data Engn & Knowledge Engn Beijing 100872 Peoples R China Hebei Univ Sch Math & Comp Sci Baoding Peoples R China North China Elect Power Univ Dept Math & Phys Beijing Peoples R China Macau Univ Sci & Technol Taipa Macau Peoples R China

In this paper, by strict mathematical reasoning, we discover the relationship between the parameters and the reducts in parameterized rough reduction. This relationship, named the nested reduction, shows that the reducts act as a nested structure with the monotonically increasing parameter. We present a systematic theoretical framework that provides some basic principles for constructing the nested structure in parameterized rough reduction. Some specific parameterized rough set models in which the nested reduction can be constructed are pointed out by strict mathematical reasoning. Based on the nested reduction, we design several quick algorithms to find a different reduct when one reduct is already given. Here 'different' refers to the reducts obtained on the different parameters. All these algorithms are helpful for quickly finding a proper reduct in the parameterized rough set models. The numerical experiments demonstrate the feasibility and the effectiveness of the nested reduction approach. (C) 2013 Elsevier Inc. All rights reserved.

关键词： Parameterized rough sets Attribute reduction Variable precision nested structure

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Microstructure and tribological characterization of magnetron sputtered MOS₂ film deposited using nested structure material

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SURFACE & COATINGS TECHNOLOGY 2006年第3-4期201卷 1006-1011页

作者： Xia, Z. Z. Tu, J. P. Lai, D. M. Zhang, L. L. Wang, Q. Chen, L. M. Chen, W. X. Zhejiang Univ Dept Mat Sci & Engn Hangzhou 310027 Peoples R China Zhejiang Univ Dept Chem Hangzhou 310027 Peoples R China

The MoS2 films were deposited on aluminum alloy substrate by magnetron sputtering the nested structure MoS2 synthesized by spray-drying method. The morphology and microstructure of the film were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscope and transmission electron microscope. The film deposited using nested MoS2 had shorter and more disorderly lamellar structure. The tribological properties of the MoS2 films were investigated using a ball-on-disk tribometer in vacuum and in humid air. The MoS2 film deposited with nested material showed lower friction coefficient and higher wear resistance compared with the layered structure (2H) MoS2 film in different environments. The superior tribological performance of film with nested material is due to its unique structure, which is in favor of both inhibition of reaction with oxygen and formation of immediate lubricant. (c) 2006 Elsevier B.V. All rights reserved.

关键词： MoS2 film nested structure tribological properties spray-drying method environment

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How does the nested structure affect policy innovation?: Empirical research on China's low carbon pilot cities

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ENERGY POLICY 2020年 144卷 111695-111695页

作者： Song, Qijiao Qin, Ming Wang, Ruichen Qi, Ye Hong Kong Univ Sci & Technol Inst Publ Policy Hong Kong Peoples R China Hong Kong Univ Sci & Technol Div Publ Policy Hong Kong Peoples R China Chongqing Technol & Business Univ Sch Accounting Chongqing Peoples R China

The pilot project of low-carbon cities is an important effort to align China's national goals for climate change governance with local governments' low-carbon behavior. The purpose of such pilot project is to promote low-carbon development and encourage policy innovation, but the role of nested structure has not been fully appreciated. Based on the survey data of low-carbon pilot cities, this paper finds that nested structure has a positive impact on policy innovation and discusses the impact on policy innovation from three dimensions: the nested pilot, the nested policy and the nested department. Heckman selection Model and Possion Model are used to make an empirical analysis of the factors influencing policy innovation and used a case study to explore the mechanism. The results show that the nested structure has a positive effect on policy innovation in pilot projects of low-carbon cities with weak incentives and weak constraints. Specifically, the participation of local governments in low-carbon related pilot projects, the number of low-carbon policies introduced by local governments, and the participation of local government departments in the process of low-carbon governance have a positive impact on policy innovation. nested structure promotes policy innovation mainly through coordination mechanism and funding mechanism.

关键词： nested structure Policy innovation Low-carbon city pilot Local government

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Design, analysis and experiment of finger soft actuator with nested structure for rehabilitation training

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ADVANCES IN MECHANICAL ENGINEERING 2020年第11期12卷

作者： Ning Meng Wang Kun Li Mingxin Yu Ke Wu Zhi Jiangnan Univ Jiangsu Key Lab Adv Food Mfg Equipment & Technol Sch Mech Engn 1800 Lihu Ave Wuxi 214122 Jiangsu Peoples R China

Compared with the rigid hand rehabilitation robot, the soft hand rehabilitation robot has the advantages of good flexibility, which is of great significance to its research. In order to make the soft hand rehabilitation robot have the advantages of high stiffness and simple manufacturing process, a nested structure is proposed for finger soft actuator in this paper. The nested structure consists of outer restraint structure and inner core structure. The inner core structure can realize deformation under the action of air pressure. The outer restraint structure can improve bending efficiency by restraining deformation in non-functional direction of inner core structure. On this basis, the processing technology of nested structure is designed, and the effect of structural parameters on performance is analyzed. In order to illustrate the advantages of nested structure, the performance of nested structure and fiber-constrained structure is compared by simulation, which includes bending angle, gripping force and expansion amount (by measuring the deformation of the cross section). The simulation results show the advantages of the nested structure. A prototype of the soft hand rehabilitation robot is developed with nested structure as finger soft actuator, and the experimental results prove the feasibility of design. The results of this study provide a reference for the structure design of soft hand rehabilitation robot.

关键词： Hand rehabilitation finger soft actuator nested structure comparison study experiment

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The Space-time Adaptive Processing Method in Airborne MIMO Radar with nested structure 4

The Space-time Adaptive Processing Method in Airborne MIMO R...

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4th IEEE International Conference on Signal and Image Processing (ICSIP)

作者： Zhou, Yan Li, Yanyan Wang, Lin Northwest Univ Sch Informat Sci & Technol Xian Peoples R China

ISBN: (纸本)9781728136608

The space-time adaptive processing (STAP) in the airborne multiple-input multiple-output (MIMO) radar with nested structure is studied. According to the special structures of arrays and transmitting pulse interval, a virtual space-time snapshot vector with longer length is constructed. Both the virtual antenna array and the virtual pulse train formed by the nested array and nested pulse train are successive and hole-free. Then a Hermitian matrix is built to estimate the full rank clutter covariance matrix in airborne MIMO radar with nested structure. For the increasing DoFs, the STAP method can achieve higher upper bound in the airborne MIMO radar with nested structure than the STAP in the traditional airborne MEMO radar, which facilitates the clutter suppression and target detection. Simulation results verify the proposed STAP method.

关键词： Space-tune adaptive processing (STAP) nested structure sparse array airborne MIMO radar

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Design of MEMS based three-axis motion stage by incorporating a nested structure

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JOURNAL OF MICROMECHANICS AND MICROENGINEERING 2014年第7期24卷 1-1页

作者： Kim, Y-S Dagalakis, N. G. Gupta, S. K. Univ Maryland Dept Mech Engn College Pk MD 20742 USA Univ Maryland Syst Res Inst College Pk MD 20742 USA Natl Inst Stand & Technol Intelligent Syst Div Engn Lab Gaithersburg MD 20899 USA

A new design of three degrees-of-freedom (DOF) translational motion stage (XYZ stage) is presented in this paper. This XYZ stage is based on MEMS and designed by combining three existing one-DOF motion stages through a nested structure. By utilizing the previously developed stages, this approach can reduce the effort for the design and analysis steps and ensure reasonable reliability. For successful implementation, electrical connection to the engaged stages, electrical isolation among them, and additional floating frames are introduced for the chosen one-DOF motion stages. With these features, the presented XYZ stage is successfully fabricated and demonstrates the range of motion of 53.98, 49.15, and 22.91 mu m along X, Y, and Z axes, respectively. The coupled motion errors among the engaged stages can be reduced to be less than 1 mu m with the proposed compensation method.

关键词： MEMS three-axis motion stage nested structure serial kinematic mechanism

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Design and analysis of a nested structure micro-displacement amplification mechanism for a galfenol-based actuator

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SMART MATERIALS AND structureS 2019年第9期28卷 095026-095026页

作者： Li, Renqiang Zhu, Yuchuan Wang, Rui Li, Yuyang Niyomwungeri, Bruno Nanjing Univ Aeronaut & Astronaut Natl Key Lab Sci & Technol Helicopter Transmiss Nanjing 210016 Jiangsu Peoples R China

In this paper, two galfenol rods are arranged in a nested structure to amplify the qmicro-displacement of an actuator. First, a finite element model of the actuator is developed to analyze the magnetization process of the actuator for different material of the sleeves. Secondly, the mathematical model of the actuator is established using the theory of magnetization, magnetostriction, and structural dynamics to describe the output displacement characteristics of the actuator at different frequencies;the hysteretic behavior of the actuator is taken into consideration and is modeled according to Jiles-Atherton hysteresis model. The experiments and results show that the output displacement of the dual galfenol rods-based actuator is significantly larger than that of a single galfenol rod-based actuator under the same experimental conditions, in addition to that, the proposed nested structure exhibits the advantages of occupying small volume and maintaining response dynamics even at high frequencies. Finally, using the established mathematical model, studies are carried out to analyze the feasibility of further amplification of the output displacement using more than two galfenol rods in a nested structure.

关键词： galfenol nested structure micro-displacement amplification magnetic field hysteresis

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Energy Use Forecasting with the Use of a nested structure Based on Fuzzy Cognitive Maps and Artificial Neural Networks

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ENERGIES 2022年第20期15卷 7542-7542页

作者： Poczeta, Katarzyna Papageorgiou, Elpiniki, I Kielce Univ Technol Dept Appl Comp Sci PL-25314 Kielce Poland Univ Thessaly Fac Technol Dept Energy Syst Geopolis 41500 Larisa Greece

The aim of this paper is to present a novel approach to energy use forecasting. We propose a nested fuzzy cognitive map in which each concept at a higher level can be decomposed into another fuzzy cognitive map, multilayer perceptron artificial neural network or long short-term memory network. Historical data related to energy consumption are used to construct a nested fuzzy cognitive map in order to better understand energy use behavior. Through the experiments, the usefulness of the nested structure in energy demand prediction is demonstrated, by calculating three popular metrics: Mean Square Error, Mean Absolute Error and the correlation coefficient. A comparative analysis is performed, applying classic multilayer perceptron artificial neural networks, long short-term memory networks and fuzzy cognitive maps. The results confirmed that the proposed approach outperforms the classic methods in terms of prediction accuracy. Moreover, the advantage of the proposed approach is the ability to present complex time series in the form of a clear nested structure presenting the main concepts influencing energy consumption on the first level. The second level allows for more detailed problem analysis and lower forecast errors.

关键词： nested structure energy use forecasting fuzzy cognitive maps artificial neural networks long short-term memory networks

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