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Modelling rapid non-destructive test using light weight deflectometer on granular soils across different degrees of saturation

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Journal of Rock Mechanics and Geotechnical engineering 2024年第7期16卷 2732-2748页

作者： Javad Ghorbani Arooran Sounthararajah Troyee Tanu Dutta Jayantha Kodikara ARC Smart Pavements Hub Dept.of Civil EngineeringMonash UniversityVIC3800Australia

This study introduces an advanced finite element model for the light weight deflectometer(LWD),which integrates contact mechanics with fully coupled *** simulating LWD tests on granular soils at various saturation levels,the model accurately reflects the dependence of the LWD modulus on dry density,water content,and effective *** model addresses and overcomes the limitations of previous finite element models for this specific ***,this research presents the first experimentally validated fully coupled contact impact ***,the research provides a comparative assessment of elastoplastic and nonlinear elastic models and contrasts an enriched node-tosegment method(developed in this study)with the more precise mortar technique for contact *** comparisons reveal unique advantages and challenges for each ***,the study underscores the importance of careful application of the LWD modulus,emphasising the need for sophisticated tools to interpret soil behaviour accurately.

关键词： Granular soils Plasticity Finite element analysis Contact mechanics Modulus Degree of saturation

Blindness-free beam scanning antenna with array of array architecture: principle,design,and experiment

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Science China(Information Sciences) 2024年第3期67卷 209-224页

作者： Jianxu SUN Yujian CHENG School of electronic Science and engineering University of electronic Science and Technology of China

This paper presents a 66–76-GHz sparsely-excited phased array antenna with the array of array(Ao A) architecture for eliminating the blindness and suppressing the grating lobe when scanning. For the array antennas printed on the thick dielectric layers with high relative permittivity, scanning blindness appears and seriously impacts the radiation performance. To address this issue, the Ao A topology is developed first. It finds that the scanning blindness appears due to the coupling of the radiating Floquet modes to the non-radiating surface wave(SW) modes. Therefore, the array is divided into two types of domino *** inner-phase distributions are introduced into the domino subarrays to break the one-to-one relationship between the Floquet mode and the SW mode. Then, the blindness inside ±60° scanning volume is eliminated by the aperiodic subarrays. Meanwhile, the aperiodic inner-phase distributions enhance the aperiodicity of the array and contribute to suppressing the grating lobe when scanning. Next, the meta-surface-based dipole with the shorted post is chosen as the unit cell for the proposed aperiodic array. Based on these methods,the array achieves the wide-scanning performance of ±60° in the E-plane and ±30° in the H-plane, without the blindness and the grating lobe. Finally, the 16×16 array is built and simulated with the dimension of32 mm × 32 mm. At the highest operating frequency, the simulated gains are 28.42, 25.17, and 24.01 d Bi when scanning to the broadside, 50° in the E-plane, and 30° in the H-plane, respectively. Compared to the ideal gain, it shows that the simulated radiation efficiency is about 84.13%, 62.08%, and 35.23% when scanning to the broadside, 50° in the E-plane, and 30° in the H-plane, respectively. The worst transmission coefficient, i.e., the worst isolation, is-11.97 d B between the central element and its two adjacent elements in the E-plane. The array prototypes are fabricated, and the experiments are carried out to ver

关键词： 6G communication systems phased array AoA aperiodic subarray wideband wide-scanning surface-wave scanning blindness grating lobe

Watt-level acousto-optically Q-switched Pr:YLF laser at 639 nm

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Chinese Optics Letters 2024年第1期22卷 76-83页

作者：薛喻宸张瑞松戴征东王中玉许惠英蔡志平 Department of electronic engineering School of Electronic Science and Engineering(National Model Microelectronics College)Xiamen UniversityXiamen 361005China

We present a study on a watt-level acousto-optically Q-switched Pr:YLF laser at three different repetition rates(10 kHz,20 kHz,and 50 kHz)for the first time,to the best of our *** corresponding average output powers and pulse widths were measured to be 1.14 W,1.2 W,and 1.32 W,and 40 ns,52 ns,and 80 ns,respectively.A maximum pulse energy of0.11 mJ was obtained,corresponding to a peak power of up to 2.8 kW at a repetition rate of 10 *** simulated dynamics of a fast Q-switched Pr:YLF laser is in agreement with the *** laser's ability to generate stable pulses with high peak power and short pulse width makes it highly desirable for various practical applications,such as laser machining and material processing.

关键词： red pulsed laser Pr:YLF diode pump acousto-optical Q switching

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Wearable Triboelectric Nanogenerators Based on Printed Polyvinylidene Fluoride Films Incorporated with Cobalt-Based Metal-Organic Framework for Self-Powered Mobile electronics

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Energy & Environmental Materials 2024年第4期7卷 396-403页

作者： Myeong-Hyeon Kim Sang-Joon Park Tae-Jun Ha Department of electronic Materials engineering Kwangwoon University

In this study,wearable triboelectric nanogenerators comprising bar-printed polyvinylidene fluoride (PVDF) films incorporated with cobalt-based metalorganic framework (Co-MOF) were *** enhanced output performance of the TENCs was attributed to the phase transition of PVDF from α-crystals to β-crystals,as facilitated by the incorporation of the MOF.

关键词： bar printing phase transition polyvinylidene fluoride incorporated with cobalt-based metal–organic framework self-powered mobile electronics wearable triboelectric nanogenerators

engineering applications and technical challenges of active array microsystems

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Frontiers of Information Technology & electronic engineering 2024年第3期25卷 342-368页

作者： Jiaguo LU Haoran ZHU East China Research Institute of electronic engineering Hefei 230039China School of electronic and Information engineering Anhui UniversityHefei 230601China

In the post-Moore era,the development of active phased array antennas will inevitably trend towards active array *** this paper,the characteristics and composition of the active array antenna are briefly *** to the high efficiency,low profile,and light weight of the active array microsystems,the application prospects and advantages in the engineering of multi-functional airborne radar,spaceborne radar,and communication systems are ***,according to the characteristics of the post-Moore era of integrated circuits,scientific and technological problems in the active array microsystems are presented,including multi-scale,multi-signal,and multi-physics field *** challenges are also discussed,such as new architectures and algorithms,miniaturization of passive components,novel materials and processes,ultra-wideband technology,and new interdisciplinary technological *** paper is expected to inspire in-depth research on active array microsystems.

关键词： Microelectronics Heterogeneous integration Packaging materials Antenna array microsystems Multi-functional radar Communication

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Influence of extraction voltage on electron and ion behavior characteristics

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Chinese Physics B 2024年第4期33卷 553-559页

作者：徐翱甘娉娉石元杰陈磊 Institute of electronic engineering China Academy of Engineering PhysicsMianyang 621999China

The characteristics of the extracted ion current have a significant impact on the design and testing of ion source *** this paper,a 2D in space and 3D in velocity space particle in cell(2D3V PIC)method is utilized to simulate plasma motion and ion extraction characteristics under various initial plasma velocity distributions and extraction voltages in a Cartesian coordinate *** plasma density is of the order of 10^(15)m^(-3)-10^(16)m^(-3)and the extraction voltage is of the order of 100 V-1000 *** study investigates the impact of various extraction voltages on the velocity and density distributions of electrons and positive ions,and analyzes the influence of different initial plasma velocity distributions on the extraction *** simulation results reveal that the main reason for the variation of extraction current is the spacecharge force formed by the relative aggregation of positive and negative net *** lays the foundation for a deeper understanding of extraction beam characteristics.

关键词： extraction voltage plasma ion beam ion current

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Visible Light Indoor Positioning System Based on Pisarenko Harmonic Decomposition and Neural Network

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Chinese Journal of electronics 2024年第1期33卷 195-203页

作者： Li ZHAO Yi REN Qi WANG Lange DENG Feng ZHANG School of electronic Information engineering Xi’an Technological University

Visible-light indoor positioning is a new generation of positioning technology that can be integrated into smart lighting and optical communications. The current received signal strength(RSS)-based visible-light positioning systems struggle to overcome the interferences of background and indoor-reflected noise. Meanwhile, when ensuring the lighting, it is impossible to use the superposition of each light source to accurately distinguish light source information; furthermore, it is difficult to achieve accurate positioning in complex indoor environments. This study proposes an indoor positioning method based on a combination of power spectral density detection and a neural network. The system integrates the mechanism for visible-light radiation detection with RSS theory, to build a back propagation neural network model fitting for multiple reflection channels. Different frequency signals are loaded to different light sources at the beacon end, and the characteristic frequency and power vectors are obtained at the location end using the Pisarenko harmonic decomposition method. Then, a complete fingerprint database is established to train the neural network model and conduct location tests. Finally, the location effectiveness of the proposed algorithm is verified via actual positioning experiments. The simulation results show that, when four groups of sinusoidal waves with different frequencies are superimposed with white noise, the maximum frequency error is 0.104 Hz and the maximum power error is 0.0362 W. For the measured positioning stage, a 0.8 m × 0.8 m × 0.8 m solid wood stereoscopic positioning model is constructed, and the average error is 4.28 cm. This study provides an effective method for separating multi-source signal energies, overcoming background noise, and improving indoor visible-light positioning accuracies.

关键词： Neural networks Measurement uncertainty Position measurement Harmonic analysis Light emitting diodes Frequency estimation Indoor positioning systems

Asymmetric Zn-N4 atomic sites embedded hollow fibers as stable Zn anode for high-performance Zn-ion hybrid capacitor

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Journal of Energy Chemistry 2024年第10期97卷 460-469页

作者： Yukun Liu Bing Li Jin Wang Caiyun Li Hongrui Yang Yang Song Sen Zhang Chao Deng Key Laboratory for Photonic and electronic Bandgap Materials Ministry of Education College of Physics and Electronic Engineering Harbin Normal University College of Material Science and Chemical engineering Harbin Engineering University

Zn based electrochemical energy storage systems（EES） have attracted tremendous interests owing to their low cost and high intrinsic ***,the uncontrolled growth of Zn dendrites and the side reactions of Zn metal anodes（ZMAs） severely restrict their *** address these issues,we design the asymmetric Zn-N4atomic sites embedded hollow fibers（AS-IHF） as the flexible host for stable *** introducing different nitrogen resources in the synthesis,two kinds of coordination,i,***-N（pyridinic） and Zn-N（pyrrolic）,are introduced in the Zn-N4atomic module *** asymmetric Zn-N4module with regulated micro-environment facilitates the superior zincophilic features and promotes the Zn ***,the highly porous structure of the hollow fiber effectively reduces local current density,homogenize Zn ion flux,and alleviate structure *** the advantages endow the high efficiency and good stability for Zn plating/*** theoretical and experimental results demonstrate the high reversibility,low nucleation overpotential,and dendritefree behavior of the AS-IHF@Zn anode,which afford the high stability in high-rate and long-term ***,the solid-state Zn-ion hybrid capacitor（ZIHC） based on AS-IHF@Zn anode shows the high flexibility,reliability,and superior long-term cycling capability in a wide-range of temperatures（-20-25℃）.Therefore,the present work not only gives a new strategy for modulating local environments of single atomic sites,but also propels the development of flexible power sources for diverse electronics.

关键词： Asymmetric coordination Dendrite free behavior Single atomic sites Zincophilic sites Zn-ion hybrid capacitor

Tunable topological polaritons by dispersion tailoring of an active metasurface

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Advanced Photonics 2024年第4期6卷 59-69页

作者： Shaojie Wang Ke Chen Shufang Dong Tian Jiang Junming Zhao Yijun Feng Nanjing University School of Electronic Science and Engineering

Hyperbolic polaritons are known to exist in materials with extreme anisotropy, exhibiting exotic optical properties that enable a plethora of unusual phenomena in the fields of polaritonics and ***, achieving simultaneous low-dimensionality, high-speed controllability, and on-demand reconfigurability of the polaritons remains unexplored despite their excellent potential in light–matter interactions, photonic integrated circuits, and optoelectronic devices. Here, we propose a metasurface approach to integrating artificially engineered electromagnetic anisotropy with fast-controllable electronic elements, offering a new route to realize active topological polaritons. Experiments showcase the proposed reconfigurable metasurface can support real-time transitions of designer polaritons from elliptical to flat, and then to hyperbolic and circular isofrequency contours. Correspondingly, the in-plane surface wavefront undergoes the transitions from convex to collimating, concave, and eventually back to convex. By exploiting the topological variations in polariton dispersions, we observe intriguing phenomena of controllable field canalization and tunable planar focusing. Furthermore, we report the concept of a planar reconfigurable integrated polariton circuit by spatially tailoring the distributions of polariton isofrequency contours, unveiling rich dispersion engineering possibilities and active control capabilities. We may provide an inspiring platform for developing planar active plasmonic devices with potential applications in subdiffraction-resolution imaging,sensing, and information processing.

关键词： active tuning anisotropic polaritons dispersion engineering hyperbolic metasurface topological transitions