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On the Directivity of Radiating Quantum Electromagnetic Systems: 《Electromagnetic Science》2024年第3期52-70,共19页Said Mikki; We explore the spatial directivity of radiating quantum source systems,which are defined as any generic source capable of producing photon emission and directing it to specific regions in space.We present a comprehens...; 关键词：Quantum source systems DIRECTIVITY Quantum antennas Quantum technologies

Superdirective Circular Arrays of Electric and Huygens Dipole Elements: 《Electromagnetic Science》2024年第1期38-62,共25页Richard W.Ziokowski; Uniform circular arrays(UCAs)provide both omnidirectional(360°)and directive(sector)coverage of the azimuthal plane.Superdirective versions with unidirectional,high front-to-back ratio(FTBR)properties could provide t...; 关键词：DIRECTIVITY Huygens dipole antennas MULTIPOLES Needle radiation Optimization Superdirective arrays Uniform circular arrays.

High‑permittivity ceramics enabled highly homogeneous zero‑index metamaterials for high‑directivity antennas and beyond被引量：2: 《eLight》2024年第1期262-271,共10页Yueyang Liu Tian Dong Xu Qin Weijia Luo Ning Leng Yujing He Yong Yuan Ming Bai Jingbo Sun Ji Zhou Yue Li Yang Li; supported by the National Key Research and Development Program of China(2021YFB2801600);National Natural Science Foundation of China(62075114),Beijing Natural Science Foundation(4212050,Z220008);Zhuhai Industry University Research Collaboration Project(ZH-22017001210108PWC).; Zero-index metamaterials(ZIMs)can support uniform electromagnetic field distributions at any frequency,but their applications are hampered by the ZIM’s homogenization level—only 3 unit cells per free-space wavelengt...; 关键词：Zero-refractive index METAMATERIALS Antenna

The influence of reflections from the train body and the ground on the sound radiation from a railway rail: 《Railway Sciences》2024年第1期1-17,共17页David J.Thompson Dong Zhao Evangelos Ntotsios Giacomo Squicciarini Ester Cierco Erwin Jansen; supported by the TRANSIT project(funded by EU Horizon 2020 and the Europe’s Rail Joint Undertaking under Grant Agreement 881771).; Purpose – The vibration of the rails is a significant source of railway rolling noise, often forming the dominantcomponent of noise in the important frequency region between 400 and 2000 Hz. The purpose of the paper ...; 关键词：Rolling noise Sound radiation Railway track Boundary elements Ground reflections DIRECTIVITY

Induced noise of impeller stuck and passive rotation state in multi-stage pump without power drive under natural flow conditions: 《Journal of Hydrodynamics》2023年第5期1008-1026,共19页Run-ze Zhou Hou-lin Liu Ru-nan Hua Liang Dong Kim Tiow Ooi Cui Dai Si-yuan Hu; Project supported by the National Natural Science Foundation of China(Grant Nos.52279087,51879122).; The natural flow cooling strategy is commonly employed in modern high-speed vessels and nuclear-powered submarines. These vessels rely on the energy generated by their own speed to drive the cooling system and supply ...; 关键词：Natural flow condition multi-stage pump flow induced noise acoustic power radiation noise directivity

Design of a High-Gain 2 × 1 Array Antenna for S-Band Applications: 《World Journal of Engineering and Technology》2023年第2期293-302,共10页Md. Imran Hossain Md. Ariful Islam Md. Tofail Ahmed Md. Humaun Kabir; Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of strength...; 关键词：Microstrip Patch Antenna Array Antenna Microstrip Feed Rectangular Patch GAIN Efficiency DIRECTIVITY ADS

5G Antenna Gain Enhancement Using a Novel Metasurface: 《Computers, Materials & Continua》2022年第8期3601-3611,共11页Mubashir Ashfaq Shahid Bashir Syed Imran Hussain Shah Nisar Ahmad Abbasi Hatem Rmili Muhammad Abbas Khan; This project was funded by the Deanship of Scientific Research(DSR),King Abdulaziz University,Jeddah,Saudi Arabia under Grant No.(KEP-PhD-13-135-42).; This article presents a Sub-6 GHz microstrip patch antenna(MPA)with enhanced gain using metamaterial(MTM)superstrate.The source MPA operates at 4.8 GHz and has a peak gain of 5.3 dBi at the resonance frequency.A windo...; 关键词：Metasurface 5G GAIN DIRECTIVITY POLARIZATION

Seismic behavior of precast segmental column bridges under near-fault forward-directivity ground motions被引量：2: 《Earthquake Engineering and Engineering Vibration》2022年第2期559-571,共13页Xin Lifeng Li Xiaozhen Fu Peiyao Mu Di; National Natural Science Foundation of China under Grant Nos.U1434205 and 51678490;the Major Research Plan of China National Railway Ministry of China under Grant Nos.2015G002-B and P2018G007;the National Key R&D Program of China under Grant No.2017YFC1500803。; Precast segmental column bridges exhibit various construction advantages in comparison to traditional monolithic column bridges.However,the lack of cognitions on seismic behaviors has seriously restricted their applic...; 关键词：precast segmental column bridge monolithic column bridge seismic behavior near-fault forward-directivity ground motion pounding effect

Low-radioactivity ultrasonic hydrophone used in positioning system for Jiangmen Underground Neutrino Observatory: 《Nuclear Science and Techniques》2022年第6期102-113,共12页Duo Teng Jiang-Lai Liu Guo-Lei Zhu Yue Meng Yuan-yuan Zhang Tao Zhang Kai Luo Rui Li Jia-Qi Hui; supported by the“trategic Priority Research Program”of the Chinese Academy of Sciences(No.XDA10010800);the National Natural Science Foundation of China(No.12074318)。; To satisfy the accurate positioning requirement of the calibration source in the Jiangmen Underground Neutrino Observatory, a Tonpilz-type hydrophone with low radioactivity and high electroacoustics is developed.The r...; 关键词：JUNO Liquid scintillator Tonpilz hydrophone Low radioactivity Sensitivity DIRECTIVITY Finite element

Three-Dimensional Visualization of Shock Cell Structure and Screech Tone Emission in Underexpanded Circular Jet: 《Journal of Flow Control, Measurement & Visualization》2022年第1期1-11,共11页Keita Ozawa Takayuki Yamagata Nobuyuki Fujisawa; The three-dimensional visualization of flow and screech-tone emission from an underexpanded circular jet is first investigated experimentally using high-speed cross-schlieren imaging and microphone measurements in the...; 关键词：Screech Tone Aeroacoustics DIRECTIVITY Frequency Spectrum Underexpanded Circular Jet Schlieren Imaging

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