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Actively Reconfigurable Valley Topological Edge and Corner States in Photonic Crystals Based on Phase Change Material Ge2Sb2Te5

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激光与光电子学进展 2024年第5期61卷 557-571页

作者： Li Wei peng yuxiang Su Peihao Li Jianbo Wang Kaijun Liu Exian Liu Jianqiang He Mengdong College of Science Hunan Province Key Laboratory of Materials Surface&Interface Science and TechnologyCentral South University of Forestry and TechnologyChangsha 410004HunanChina College of Science Jiujiang UniversityJiujiang 332005JiangxiChina

The immunity of topological states against backscattering and structural defects provides them with a unique advantage in the exploration and design of high-precision low-loss optical ***,the operating bandwidth of the topological states in certain photonic structures is difficult to actively tune and flexibly *** this study,we propose a valley topological photonic crystal(TPC)comprising two inverse honeycomb photonic crystals,consisting of hexagonal silicon and Ge2Sb2Te5(GST)*** GST transitions from the amorphous phase to the crystalline phase,the edge band of the TPC appears as a significant redshift and is inversed from a“∪”to an“∩”shape with topological phase transition,which enables active tuning of the operating bandwidth and propagation direction of topological edge *** the topological edge and corner states in a triangular structure constructed using TPCs can be simultaneously adjusted and reconfigured via GST phase transition,along with a change in the group number of corner *** the adjustability of topological edge states and electromagnetic coupling between two different topological bearded interfaces,we develop a multichannel optical router with a high tuning degree of freedom,where channels can be actively reconfigured and their on/off states can be freely *** study provides a strategy for the active regulation of topological states and may be beneficial for the development of reconfigurable topological optical devices.

关键词： topological edge states topological corner states phase change material active reconfiguration topological photonic crystal

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燃料电池废热驱动弹热制冷装置性能分析

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汽车工程 2024年第4期46卷 662-668页

作者：彭钰祥余庆华敖瑞颜伏伍武汉理工大学现代汽车零部件技术湖北省重点实验室湖北省新能源与智能网联车工程技术研究中心武汉430070

热驱动弹热制冷是利用形状记忆合金被加热变形来驱动弹热材料相变从而产生制冷效应的新型固态制冷技术。本文设计了一种将弹热制冷装置与燃料电池相结合的组合系统,利用燃料电池产生的废热来驱动弹热制冷装置,以提高能量利用效率,并产... 详细信息

热驱动弹热制冷是利用形状记忆合金被加热变形来驱动弹热材料相变从而产生制冷效应的新型固态制冷技术。本文设计了一种将弹热制冷装置与燃料电池相结合的组合系统,利用燃料电池产生的废热来驱动弹热制冷装置,以提高能量利用效率,并产生制冷效果。基于燃料电池和弹热制冷的工作原理,采用Simulink建立了全系统动态耦合仿真模型,研究了组合系统的动态工作特性,并分析了运行参数对系统性能的影响规律。结果表明:增加弹热制冷装置能提高整个系统的能量利用效率,电堆工作温度为80℃时该系统可产生1.76 kW的制冷功率,调整电堆工作压强至2.5 atm可最大化系统的综合输出功率和运行效率,电堆电流密度对组合系统的输出功率和运行效率呈现相反的影响趋势。

关键词：质子交换膜燃料电池弹热制冷废热回收

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盾构预拌砂浆运输中离析程度分析及优化

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广西科技大学学报 2024年第3期35卷 41-47页

作者：周红梅张毅翔彭昱翔广西科技大学土木建筑工程学院广西柳州545006

由于盾构预拌砂浆在使用移动筒仓运输的过程中容易产生离析,因此,对已在实际生产中使用的盾构预拌砂浆在不同条件下的离析程度进行研究。在竖直振动模拟条件下,结合颗粒物质理论,以4种不同粒径的颗粒为材料,研究振动时长、砂粒径和分隔... 详细信息

由于盾构预拌砂浆在使用移动筒仓运输的过程中容易产生离析,因此,对已在实际生产中使用的盾构预拌砂浆在不同条件下的离析程度进行研究。在竖直振动模拟条件下,结合颗粒物质理论,以4种不同粒径的颗粒为材料,研究振动时长、砂粒径和分隔空间百分比等3种不同因素对离析程度的影响,用粗料含量变化来表征离析发生的规律,结果表明:振动时间超过60s时,离析程度显示为无明显变化的平缓曲线;粗颗粒粒径越大,分隔空间越大,离析程度越大。使用Design-expert11对试验结果进行综合分析,结果表明:各因素对盾构预拌砂浆离析指数的影响由大到小依次为振动时长、分隔空间百分比、砂粒径;当振动时长为180 s,砂粒径为0.3mm,分隔空间为25%时,离析程度最小,即为最佳方案。

关键词：盾构预拌砂浆移动筒仓离析

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SeedLink地震数据实时传输服务器搭建

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华南地震 2024年第1期44卷 111-118页

作者：吕帅杨周胜粟毅彭钰翔刘鹏飞云南省地震局昆明650224 中国地质大学(北京)信息工程学院北京100083

利用运营商网络将地震监测数据实时传输至本地数据中心进行在线处理是全球各地地震台网的通用做法,IRIS和GFZ等机构提供了基于SeedLink协议的地震数据共享服务器,用户既能通过互联网快速获取数据到本地,又能通过Seiscomp和Earthworm等... 详细信息

利用运营商网络将地震监测数据实时传输至本地数据中心进行在线处理是全球各地地震台网的通用做法,IRIS和GFZ等机构提供了基于SeedLink协议的地震数据共享服务器,用户既能通过互联网快速获取数据到本地,又能通过Seiscomp和Earthworm等系统进行实时地震监测。目前国内测震台网使用NetSeis/IP协议和Http协议进行数据分发,通过Jopens MSDP软件进行在线处理。由于国内外采用不一样的数据传输协议,国内数据流不能直接接入Seiscomp和Earthworm等系统使用。为解决这个问题,介绍了NetSeis/IP和SeedLink等国内外主流地震数据实时传输协议,对协议指令及数据请求方式进行了详细描述,提出了一种基于RingServer快速搭建轻量级SeedLink实时数据流服务器的方法,可实现SeedLink服务器功能,一方面满足Seiscomp和Earthworm等国际地震监测系统的数据接入需要,另一方面为我国地震数据在线共享提供参考。

关键词：传输协议 Seedlink 地震数据 RingServer NetSeis/IP

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Research on a multi‑dimensional image information fusion algorithm based on NSCT transform

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Frontiers of Optoelectronics 2024年第1期17卷 29-44页

作者： yuxiang Su Xi Liang Danhua Cao Zhenyu Yang Yuanlong peng Ming Zhao School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China State Grid Information and Telecommunication Branch Beijing 100761China

Traditional inspection cameras determine targets and detect defects by capturing images of their light intensity,but in complex environments,the accuracy of inspection may *** based on polarization of light can characterize various features of a material,such as the roughness,texture,and refractive index,thus improving classification and recognition of *** paper uses a method based on noise template threshold matching to denoise and preprocess polarized *** also reports on design of an image fusion algorithm,based on NSCT transform,to fuse light intensity images and polarized *** results show that the fused image improves both subjective and objective evaluation indicators,relative to the source image,and can better preserve edge information and help to improve the accuracy of target *** study provides a reference for the comprehensive application of multi-dimensional optical information in power inspection.

关键词： Power inspection Object detection Polarization imaging Image fusion Image denoising

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Modulating charge separation and transfer for high-performance photoelectrodes via built-in electric field

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1126-1146页

作者： Houyan Cheng peng Liu Yuntao Cui Ru Ya yuxiang Hu Jinshu Wang Key Laboratory of Advanced Functional Materials of Education Ministry of China Faculty of Engineering and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of Cryogenic Science and Technology and Beijing Key Lab of Cryo-Biomedical Engineering Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Inner Mongolia Academy of Science and Technology Hohhot 010020China

Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical ***,considerable efforts have been devoted to this *** review systematically summarizes the impact of built-in electric fields on enhancing charge separation and transfer mechanisms,focusing on the modulation of built-in electric fields in terms of depth and ***,mechanisms and tuning strategies for built-in electric fields are ***,the state-of-the-art works regarding built-in electric fields for modulating charge separation and transfer are summarized and categorized according to surface and interface ***,current strategies for constructing bulk built-in electric fields in photoelectrodes are explored,and insights into future developments for enhancing charge separation and transfer in high-performance photoelectrochemical applications are provided.

关键词： photoelectrochemical water splitting bulk built-in electric field cation intercalation charge separation and transfer

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Realtime observation of “spring fracture” like AlGaN/GaN HEMT failure under bias

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Science China(Information Sciences) 2024年第1期67卷 303-305页

作者： Qing ZHU Zhenni WANG yuxiang WEI Ling YANG Xiaoli LU Jiejie ZHU peng ZHONG Yimin LEI Xiaohua MA School of Microelectronics Xidian University State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology Xidian University School of Advanced Materials and Nanotechnology Xidian University

The AlGaN/GaN HEMTs have been considered promising candidates for high-frequency and high-power applications,while the reliability issues greatly limit the commercialization of AlGaN/GaN HEMTs. In the past, the research on the reliability of devices was often based on Raman spectroscopy, cathodoluminescence, and TEM after failure of the devices, which is often considered to be the laborious and complicated “archaeological” kind of analysis [1].

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Characterization of multi-scale ionospheric irregularities using ground-based and space-based GNSS observations

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Satellite Navigation 2021年第1期2卷 192-212页

作者： yuxiang peng Wayne A Scales Michael D Hartinger Zhonghua Xu Shane Coyle Center for Space Science and Engineering Research Virginia TechBlacksburgVA 24061USA Bradley Department of Electrical and Computer Engineering Virginia TechBlacksburgVA 24061USA Space Science Institute BoulderCO 80301USA National Institute of Aerospace HamptonVA 23666USA Center for Space Science and Engineering Research Virginia TechBlacksburgVA 24061USA.

Ionospheric irregularities can adversely affect the performance of Global Navigation Satellite System (GNSS). How-ever, this opens the possibility of using GNSS as an effective ionospheric remote sensing tool. Despite ionospheric monitoring has been undertaken for decades, these irregularities in multiple spatial and temporal scales are still not fully understood. This paper reviews Virginia Tech’s recent studies on multi-scale ionospheric irregularities using ground-based and space-based GNSS observations. First, the relevant background of ionospheric irregularities and their impact on GNSS signals is reviewed. Next, three topics of ground-based observations of ionospheric irregulari-ties for which GNSS and other ground-based techniques are used simultaneously are reviewed. Both passive and active measurements in high-latitude regions are covered. Modelling and observations in mid-latitude regions are considered as well. Emphasis is placed on the increased capability of assessing the multi-scale nature of ionospheric irregularities using other traditional techniques (e.g., radar, magnetometer, high frequency receivers) as well as GNSS observations (e.g., Total-Electron-Content or TEC, scintillation). Besides ground-based observations, recent advances in GNSS space-based ionospheric measurements are briefly reviewed. Finally, a new space-based ionospheric observa-tion technique using GNSS-based spacecraft formation flying and a differential TEC method is demonstrated using the newly developed Virginia Tech Formation Flying Testbed (VTFFTB). Based on multi-constellation multi-band GNSS, the VTFFTB has been developed into a hardware-in-the-loop simulation testbed with external high-fidelity global ionospheric model(s) for 3-satellite formation flying, which can potentially be used for new multi-scale ionospheric measurement mission design.

关键词： GNSS Ionospheric irregularities Remote sensing Active experiment Spacecraft formation flying

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Elucidating and manipulating pressure-induced water intrusion–extrusion in tunable hydrophobic Co/Zn bimetallic ZIFs:Roles of pore size and hydrogen bond

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Nano Research 2024年第1期17卷 344-353页

作者： Diyi Fang Chuanlei Liu Yu Chen Qilong peng Kongguo Wu yuxiang Chen Hao Jiang Yuan Wu Benxian Shen Qiumin Wu Di Wu Hui Sun International Joint Research Center of Green Energy Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China Alexandra Navrotsky Institute for Experimental Thermodynamics The Gene and Linda Voiland School of Chemical Engineering and BioengineeringMaterials Science and Engineeringand Department of ChemistryWashington State UniversityWashington 99163USA

Porous heterogeneous lyophobic systems(HLSs)find potential applications in energy restoring,dissipating,and ***,the development of controllable HLSs still lacks rational structure design of nanoporous materials matching the molecular sizes of adopted *** that,thoroughly understanding the underlying transportation mechanism in the confined nano channels is greatly *** this work,a series of Co/Zn bimetallic zeolitic imidazolate frameworks(ZIFs)with tunable structures were synthesized via regulating the Co to Zn ratios and employed to investigate the intrusion–extrusion of liquid water in confined *** characterizations confirm the heterometallic coordination in the Co/Zn-doped *** intrusion–extrusion experiments unlock the relationship between the intrusion pressure and the nanopore size and realize the evolution of the HLSs between molecular spring and *** addition,cycling tests indicate the reversible structure change of Co/Zn ZIFs encountering pressure-induced water *** combination with molecular dynamics simulations,we present that the water multimers intrude into nanopores of ZIFs in chain-like forms along with dissociation of hydrogen bonds(HBs).Water molecules in the pre-intrusion state exhibit reduced HBs in response to the increase of pressure and linear structure with 1.6–3.0 HBs on *** transition to the post-intrusion situation,the associative configuration of water tends to exhibit the tetrahedral ***,we highlight the roles of pore size and HB in synergically dominating the pressure-induced intrusion–extrusion of liquid water in hydrophobic ***,the present work can also guide the development of functional guest–host systems based on porous architectures.

关键词： heterometallic zeolitic imidazolate frameworks nanopore intrusion hydrogen bonds

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近场水下爆炸瞬态强非线性流固耦合无网格数值模拟研究

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力学学报 2022年第8期54卷 2194-2209页

作者：王平平张阿漫彭玉祥孟子飞哈尔滨工程大学船舶工程学院哈尔滨150001 中山大学海洋工程与技术学院广东珠海519000

近场水下爆炸涉及多相流体的掺杂耦合以及结构的大变形、损伤和断裂等瞬态强非线性现象,传统的网格算法在模拟近场水下爆炸时面临结构网格畸变、多相界面捕捉精度不足等难题,鉴于此,本文建立了完全无网格的近场水下爆炸冲击波和气泡全... 详细信息

近场水下爆炸涉及多相流体的掺杂耦合以及结构的大变形、损伤和断裂等瞬态强非线性现象,传统的网格算法在模拟近场水下爆炸时面临结构网格畸变、多相界面捕捉精度不足等难题,鉴于此,本文建立了完全无网格的近场水下爆炸冲击波和气泡全物理过程瞬态强非线性流固耦合动力学模型.流体采用基于黎曼求解器的光滑粒子流体动力学(SPH)方法求解,结构采用重构核粒子法(RKPM)求解,并基于法向通量边界条件实现流固耦合.为提高SPH对流场间断的求解精度,引入黎曼问题思想并结合MUSCL重构算法,为解决流场粒子体积变化剧烈导致的精度下降问题,应用了自适应粒子分割与合并方法.为模拟水下爆炸对结构造成的损伤断裂,基于退化实体几何表述,采用Lemaitre损伤算法,建立了RKPM壳结构断裂损伤模型.依据所建立的SPH-RKPM流固耦合模型,对近场水下爆炸冲击波传播、气泡脉动与射流以及结构毁伤进行了模拟,将得到的冲击波载荷、气泡演化以及结构响应与实验值和其他数值解对比,验证了当前建立的SPH-RKPM流固耦合模型的有效性和精度,并给出了水下爆炸载荷特性及其对结构的流固耦合毁伤机制与规律,旨在为近场水下爆炸载荷预报提供理论和基础性技术支撑,为毁伤威力评估和舰船防护结构设计提供参考.

关键词：水下爆炸光滑粒子流体动力学重构核函数粒子法流固耦合结构毁伤

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