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Antenna Decoupling Based on Characteristic Modes Cancellation

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Chinese Journal of Electronics 2022年第6期31卷 1138-1145页

作者： CHU Qingxin zeng Wenfeng School of Electronic and Information Engineering South China University of Technology

The demand for a high transmission data rate in 5G leads to the wide application of the multi-input, multi-output(MIMO) technique. However, the narrow design space in mobile phone causes severe unexpected coupling between antenna units and deteriorate the system performance dramatically. In this paper, we focus on the antenna coupling within the MIMO system. Some decoupling techniques are summarized, such as neutralization line, decoupling network, common/differential mode cancellation, etc. Finally, new decoupling research developments of modal currents cancellation based on the theory of characteristic mode are elaborated. Two design examples are shown to validate the benefit of the proposed decoupling method. The-6 dB impedance bandwidth of the head-to-head antenna pair can cover 3.4–3.6 *** isolation level is improved from more than 3.7 dB to more than 13 dB. The tail-to-tail antenna pair can cover 3.3–5 GHz and the isolation level is improved from more than 5 dB to more than 10 dB in the whole operating bandwidth. Both antenna pairs can achieve an envelop correlation coefficient of less than 0.2 and the antenna efficiencies are more than 40%.

关键词： neutralization line severe unexpected coupling mobile phone antenna pairs 3.3-5 GHz antenna units antenna radiation patterns narrow design space high transmission data rate mobile handsets multiinput MIMO system multioutput technique 5G mobile communication characteristic mode decoupling method 6 dB impedance bandwidth antenna efficiencies antenna coupling MIMO communication system performance antenna decoupling modal currents cancellation characteristic modes cancellation isolation level tail-to-tail antenna pair head-to-head antenna pair decoupling research developments decoupling techniques

Structural transition dynamics of the formation of warm dense gold: From an atomic scale view

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Science China(Physics,Mechanics & Astronomy) 2020年第6期63卷 33-41页

作者： QiYu zeng JiaYu Dai Department of Physics National University of Defense TechnologyChangsha 410073China

With the highly optimized embedded-atom-method(EAM)potential and electron-phonon coupling factor obtained from experimental data,the dynamics of the formation of warm dense gold and the nuclear response of gold foils upon intense laser excitation were investigated using two-temperature molecular dynamics *** laser energy densities ranging from 0.18 to 1.17 MJ/kg,we provide a microscopic picture of the formation of warm dense gold.A threshold(0.19 MJ/kg)for the laser energy density was determined,identifying two different melting *** an energy density below 0.19 MJ/kg,the melting of the foil is controlled by the propagation of melt fronts from external surfaces,which results in heterogeneous melting on the time scale of hundreds of *** an energy density above 0.19 MJ/kg,homogeneous nucleation and growth of liquid regions inside the foil play the leading role,and homogeneous melting occurs with several *** with previous simulations and experimental measurements,the evaluated different threshold value indicates that the improvement in the electron heat capacity for the two-temperature model by including the kinetic information of electrons may predict better laser-matter interactions under such extreme non-equilibrium conditions.

关键词： molecular dynamics numerical methods solid-liquid transitions laser ablation of solids

The midas touch on copper into palladium

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Science China Chemistry 2020年第12期63卷 1740-1741页

作者： Jie zeng Hefei National Laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China

The catalytic semi-hydrogenation of alkynes(C≡C) to alkenes(C=C) has long been a crucial and challenging step in industry as it restrains the tendency of over-hydrogenation towards substrates [1]. Up to now, Pd-based catalysts show ultrahigh activity and selectivity towards the semihydrogenation of alkynes and are commonly used in industry, while metals such as Cu, Ag and Au exhibit relatively low activity due to their poor hydrogen activation ability.

关键词： hydrogenation palladium semi

An overview on integrated localization and communication towards 6G

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Science China(Information Sciences) 2022年第3期65卷 5-50页

作者： Zhiqiang XIAO Yong zeng National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories

While the fifth generation(5 G) cellular system is being deployed worldwide, researchers have started the investigation of the sixth generation(6 G) mobile communication networks. Although the essential requirements and key usage scenarios of 6 G are yet to be defined, it is believed that 6 G should be able to provide intelligent and ubiquitous wireless connectivity with Terabits per second(Tbps) data rate and submillisecond(sub-ms) latency over three-dimensional(3 D) network coverage. To achieve such goals, acquiring accurate location information of the mobile terminals is becoming extremely useful, not only for locationbased services but also for improving wireless communication performance in various ways such as channel estimation, beam alignment, medium access control, routing, and network optimization. On the other hand, the advancement of communication technologies also brings new opportunities to greatly improve the localization performance, as exemplified by the anticipated centimeter-level localization accuracy in 6 G by extremely large-scale multiple-input multiple-output(MIMO) and millimeter wave(mm Wave) *** this regard, a unified study on integrated localization and communication(ILAC) is necessary to unlock the full potential of wireless networks for dual purposes. While there are extensive studies on wireless localization or communications separately, the research on ILAC is still in its infancy. Therefore, this article aims to give a tutorial overview on ILAC towards 6 G wireless networks. After a holistic survey on wireless localization basics, we present the state-of-the-art results on how wireless localization and communication inter-play with each other in various network layers, together with the main architectures and techniques for localization and communication co-design in current two-dimensional(2 D) and future 3 D networks with aerial-ground integration. Finally, we outline some promising future research directions for ILAC.

关键词： wireless localization integrated localization and communication cellular networks B5G 6G

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The Invertibility of Rational Univariate Representations

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Journal of Systems Science & Complexity 2022年第6期35卷 2430-2451页

作者： XIAO Shuijing zeng Guangxing Department of Mathematics Nanchang UniversityNanchang 330031China

In this paper,the so-called invertibility is introduced for rational univariate representations,and a characterization of the invertibility is *** is shown that the rational univariate representations,obtained by both Rouillier’s approach and Wu’s method,are ***,the ideal created by a given rational univariate representation is *** results on invertible rational univariate representations and created ideals are *** on these results,a new approach is presented for decomposing the radical of a zero-dimensional polynomial ideal into an intersection of maximal ideals.

关键词： Invertibility polynomial ideal rational univariate representation(RUR) Wu’s method zero-dimensional

Single metal atom decorated photocatalysts:Progress and challenges

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Nano Research 2021年第4期14卷 934-944页

作者： Lei zeng Can Xue School of materials science and engineering Nanyang Technological University50 Nanyang avenueSingapore 639798Singapore

Photocatalysis has attracted intense attention due to its potential to solve the energy resource problem and environmental *** single metal atom decorated photocatalysts as a rising star become more and more popular because of the unique advantages of superior catalytic activities and ultrahigh atom utilization *** key function of single metal atom catalysts in photocatalytic reactions is boosting surface redox reactions by utilizing photogenerated charges,and has been verified by various spectroscopic and microscopic ***,the activities of the single metal atoms highly depend on the binding environment in the host photocatalyst that affect the adsorption and activation of reactants as well as the reaction energy ***,this mini review summarizes recent progress on single metal atom decorated photocatalysts,and discusses the roles of the single metal atom catalysts in different types of host photocatalysts including organic,carbon-based and inorganic *** remaining challenges and future perspectives on the stability and activities of single atom catalysts in photocatalytic processes are elaborated in the *** believe that this mini review will provide valuable overview on synthetic methods of different single atom photocatalysts for researchers towards future development of highly efficient photocatalysts.

关键词： photocatalysis solar fuels hydrogen generation CO_(2)reduction artificial photosynthesis solar energy conversion

Heilbronn's Problem of Eight Points in the Square

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Journal of Systems Science & Complexity 2022年第6期35卷 2452-2480页

作者： DEHBI Lydia zeng Zhenbing School of Software Engineering East China Normal UniversityShanghai 200062China Department of Mathematics Shanghai UniversityShanghai 200444China

In this work the authors consider the problem of optimally distributing 8 points inside a unit square so that the smallest area of the(38)triangles formed by them is *** computations are employed to reduce the problem... 详细信息

关键词： Global search Heilbronn’s problem optimal configuration smallest triangle’s area symbolic computations

Systems Theory-Driven Framework for AI Integration into the Holistic Material Basis Research of Traditional Chinese Medicine

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Engineering 2024年第9期40卷 28-50页

作者： Jingqi zeng Xiaobin Jia School of Traditional Chinese Pharmacy China Pharmaceutical UniversityNanjing 211198China State Key Laboratory of Natural Medicines China Pharmaceutical UniversityNanjing 210009China

This paper introduces a systems theory-driven framework to integration artificial intelligence(AI)into traditional Chinese medicine(TCM)research,enhancing the understanding of TCM’s holistic material basis while adhering to evidence-based *** the System Function Decoding Model(SFDM),the research progresses through define,quantify,infer,and validate phases to systematically explore TCM’s material *** employs a dual analytical approach that combines top-down,systems theory-guided perspectives with bottom-up,elements-structure-function methodologies,provides comprehensive insights into TCM’s holistic material ***,the research examines AI’s role in quantitative assessment and predictive analysis of TCM’s material components,proposing two specific AIdriven technical *** interdisciplinary effort underscores AI’s potential to enhance our understanding of TCM’s holistic material basis and establishes a foundation for future research at the intersection of traditional wisdom and modern technology.

关键词： Artificial intelligence Systems theory Traditional Chinese medicine Material basis Bottom-up

Expansion Strategies and Evolution Paths of Hotel Groups in China

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Chinese Geographical Science 2010年第4期20卷 372-380页

作者： zeng Guojun School of Tourism Management SUN Yat-Sen University Guangzhou 510275 China

The organizational structure change of enterprises should be subject to the change of strategy,and strategy change is the reaction to the environment *** paper studied the expansion strategies and evolution paths of hotel groups in China by a survey in 2007,in which the research objects were 91 hotel groups listed by China Tourist Hotels *** conclusions are drawn:based on the two dimensions of unification management function scope and the unification management degree,hotel groups can be divided into four strategic types,including strategically concentrated group,close function group,widespread alliance group and loose union *** there are three different expansion paths:stability path,growth path and undulation *** 72.5% of Chinese hotel groups have a stability or growth expansion path.

关键词： expansion strategy evolution path hotel group China