检索结果-南通市图书馆

Nonlinear control of photonic higher-order topological bound states in the continuum

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2021年第9期10卷 1726-1735页

作者： Zhichan Hu Domenico Bongiovanni Dario Jukić Ema Jajtić shiqi xia Daohong Song Jingjun Xu Roberto Morandotti Hrvoje Buljan Zhigang Chen The MOE Key Laboratory of Weak-Light Nonlinear Photonics TEDA Applied Physics Institute and School of PhysicsNankai University300457TianjinChina INRS-EMT 1650 Boulevard Lionel-BouletVarennesQCJ3X 1S2Canada Faculty of Civil Engineering University of ZagrebA.Kačića Miošića 2610000ZagrebCroatia Department of Physics Faculty of ScienceUniversity of ZagrebBijenička c.3210000ZagrebCroatia Collaborative Innovation Center of Extreme Optics Shanxi University030006TaiyuanShanxiChina Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China610054ChengduSichuanChina Department of Physics and Astronomy San Francisco State UniversitySan FranciscoCA94132USA

Higher-order topological insulators(HOTIs)are recently discovered topological phases,possessing symmetry-protected corner states with fractional *** unexpected connection between these states and the seemingly unrelated phenomenon of bound states in the continuum(BICs)was recently *** nonlinearity is added to the HOTI system,a number of fundamentally important questions *** example,how does nonlinearity couple higher-order topological BICs with the rest of the system,including continuum states?In fact,thus far BICs in nonlinear HOTIs have remained *** we unveil the interplay of nonlinearity,higher-order topology,and BICs in a photonic *** observe topological corner states that are also BICs in a laser-written second-order topological lattice and further demonstrate their nonlinear coupling with edge(but not bulk)modes under the proper action of both self-focusing and defocusing ***,we calculate the eigenvalue spectrum and analog of the Zak phase in the nonlinear regime,illustrating that a topological BIC can be actively tuned by nonlinearity in such a photonic *** studies are applicable to other nonlinear HOTI systems,with promising applications in emerging topology-driven devices.

关键词： topological nonlinearity nonlinear

Topologically tuned terahertz confinement in a nonlinear photonic chip

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第6期11卷 1296-1303页

作者： Jiayi Wang shiqi xia Ride Wang Ruobin Ma Yao Lu Xinzheng Zhang Daohong Song Qiang Wu Roberto Morandotti Jingjun Xu Zhigang Chen The MOE Key Laboratory of Weak-Light Nonlinear Photonics TEDA Institute of Applied Physics and School of PhysicsNankai UniversityTianjin 300457China Innovation Laboratory of Terahertz Biophysics National Innovation Institute of Defense Technology100071 BeijingChina Collaborative Innovation Center of Extreme Optics Shanxi University030006 TaiyuanShanxiChina INRS-EMT 1650 Blvd.Lionel-BouletVarennesQC J3X 152Canada

Compact terahertz(THz)functional devices are greatly sought after for high-speed wireless communication,biochemical sensing,and non-destructive ***,controlled THz generation,along with transport and detection,has remained a challenge especially for chip-scale devices due to low-coupling efficiency and unavoidable absorption ***,based on the topological protection of electromagnetic waves,we demonstrate nonlinear generation and topologically tuned confinement of THz waves in an engineered lithium niobate chip forming a wedge-shaped Su-Schrieffer-Heeger *** measured band structures provide direct visualization of the THz localization in the momentum space,while robustness of the confined mode against chiral perturbations is also analyzed and compared for both topologically trivial and nontrivial *** topological control of THz waves may bring about new possibilities in the realization of THz integrated circuits,promising for advanced photonic applications.

关键词： nonlinear realization wedge

Nontrivial coupling of light into a defect:the interplay of nonlinearity and topology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2020年第1期9卷 646-655页

作者： shiqi xia Dario Jukic Nan Wang Daria Smirnova Lev Smirnov Liqin Tang Daohong Song Alexander Szameit Daniel Leykam Jingjun Xu Zhigang Chen Hrvoje Buljan The MOE Key Laboratory of Weak-Light Nonlinear Photonics TEDA Applied Physics Institute and School of PhysicsNankai UniversityTianjin 300457China Faculty of Civil Engineering University of ZagrebA.Kacica Miosica 2610000 ZagrebCroatia Nonlinear Physics Centre Research School of PhysicsAustralian National UniversityCanberraACT 2601Australia Institute of Applied Physics Russian Academy of ScienceNizhny Novgorod 603950Russia Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006 ShanxiPR China Institut für Physik Universitat RostockAlbert-Einstein-Strasse 2318059 RostockGermany Center for Theoretical Physics of Complex Systems Institute for Basic Science(IBS)Daejeon 34126Republic of Korea Basic Science Program Korea University of Science and TechnologyDaejeon 34113Republic of Korea Department of Physics and Astronomy San Francisco State UniversitySan FranciscoCA 94132USA Department of Physics Faculty of ScienceUniversity of ZagrebBijenička c.3210000 ZagrebCroatia

The flourishing of topological photonics in the last decade was achieved mainly due to developments in linear topological photonic ***,when nonlinearity is introduced,many intriguing questions *** example,are there universal fingerprints of the underlying topology when modes are coupled by nonlinearity,and what can happen to topological invariants during nonlinear propagation?To explore these questions,we experimentally demonstrate nonlinearity-induced coupling of light into topologically protected edge states using a photonic platform and develop a general theoretical framework for interpreting the mode-coupling dynamics in nonlinear topological *** on laser-written photonic Su-Schrieffer-Heeger lattices,our experiments show the nonlinear coupling of light into a nontrivial edge or interface defect channel that is otherwise not permissible due to topological *** theory explains all the observations ***,we introduce the concepts of inherited and emergent nonlinear topological phenomena as well as a protocol capable of revealing the interplay of nonlinearity and *** concepts are applicable to other nonlinear topological systems,both in higher dimensions and beyond our photonic platform.

关键词： nonlinearity topological coupling

Nonlinear topological valley Hall edge states arising from type-Ⅱ Dirac cones

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advanced Photonics 2021年第5期3卷 44-51页

作者： Hua Zhong shiqi xia Yiqi Zhang Yongdong Li Daohong Song Chunliang Liu Zhigang Chen Xi’an Jiaotong University School of Electronic Science and EngineeringKey Laboratory for Physical Electronics and Devices of the Ministry of Education&Shaanxi Key Lab of Information Photonic TechniqueFaculty of Electronic and Information EngineeringXi’anChina Nankai University TEDA Applied Physics Institute and School of PhysicsMOE Key Laboratory of Weak-Light Nonlinear PhotonicsTianjinChina San Francisco State University Department of Physics and AstronomySan FranciscoCaliforniaUSA

A Dirac point is a linear band crossing point originally used to describe unusual transport properties of materials like *** recent years,there has been a surge of exploration of type-II Dirac/Weyl points using various engineered platforms including photonic crystals,waveguide arrays,metasurfaces,magnetized plasma and polariton micropillars,aiming toward relativistic quantum emulation and understanding of exotic topological *** endeavors,however,have focused mainly on linear topological states in real or synthetic Dirac/Weyl *** propose and demonstrate nonlinear valley Hall edge(VHE)states in laserwritten anisotropic photonic lattices hosting innately the type-Ⅱ Dirac *** self-trapped VHE states,manifested as topological gap quasi-solitons that can move along a domain wall unidirectionally without changing their profiles,are independent of external magnetic fields or complex longitudinal modulations,and thus are superior in comparison with previously reported topological edge *** finding may provide a route for understanding nonlinear phenomena in systems with type-Ⅱ Dirac points that violate the Lorentz invariance and may bring about possibilities for subsequent technological development in light field manipulation and photonic devices.

关键词： photonic topological insulator type-ⅡDirac cone valley Hall edge soliton

Deep-learning-empowered synthetic dimension dynamics:morphing of light into topological modes

在线全文

学校读者我要写书评

暂无评论

Advanced Photonics 2024年第2期6卷 61-68页

作者： shiqi xia Sihong Lei Daohong Song Luigi Di Lauro Imtiaz Alamgir Liqin Tang Jingjun Xu Roberto Morandotti Hrvoje Buljan Zhigang Chen Nankai University TEDA Institute of Applied PhysicsSchool of PhysicsThe MOE Key Laboratory of Weak-Light Nonlinear PhotonicsTianjinChina Shanxi University Collaborative Innovation Center of Extreme OpticsTaiyuanChina INRS-EMT VarennesQuebecCanada University of Zagreb Department of PhysicsFaculty of ScienceZagrebCroatia

Synthetic dimensions(SDs)opened the door for exploring previously inaccessible phenomena in high-dimensional ***,construction of synthetic lattices with desired coupling properties is a challenging and unintuitive ***,we use deep learning artificial neural networks(ANNs)to construct lattices in real space with a predesigned spectrum of mode eigenvalues,and thus to validly design the dynamics in synthetic mode *** employing judiciously chosen perturbations(wiggling of waveguides at desired frequencies),we show resonant mode coupling and tailored dynamics in *** distinct examples are illustrated:one features uniform synthetic mode coupling,and the other showcases the edge defects that allow for tailored light transport and ***,we demonstrate morphing of light into a topologically protected edge mode with modified Su-Schrieffer-Heeger photonic *** an ANN-assisted construction of SDs may advance toward“utopian networks,”opening new avenues for fundamental research beyond geometric limitations as well as for applications in mode lasing,optical switching,and communication technologies.

关键词： synthetic dimensions deep learning mode manipulation topological mode morphing photonic lattices

轴向柱塞泵柱塞滑靴组件动力学特性建模与分析

在线全文

学校读者我要写书评

暂无评论

农业机械学报 2016年第3期47卷 373-380页

作者：胡敏徐兵周万仁夏士奇浙江大学流体动力与机电系统国家重点实验室杭州310027

柱塞滑靴组件的动力学特性直接决定了泵的工作性能。泵运转周期内,存在如离心力、滑靴副摩擦力及柱塞与缸孔间接触力等大小和方向都时变的作用力,但长期以来在对柱塞滑靴组件的动力学参数分析中,仅局限于或在某一固定位置处、或在简化... 详细信息

柱塞滑靴组件的动力学特性直接决定了泵的工作性能。泵运转周期内,存在如离心力、滑靴副摩擦力及柱塞与缸孔间接触力等大小和方向都时变的作用力,但长期以来在对柱塞滑靴组件的动力学参数分析中,仅局限于或在某一固定位置处、或在简化假设情况下进行计算,这给泵结构的优化设计及泵性能的预期评估带来不利影响。为在全周期内动态评估柱塞滑靴组件的动力学性能,依据不同应用需要,在简化受力情况下提出了相应的简化数学模型,在完整受力情况下,通过引入随体坐标系,提出了相应的精细数学模型。建立的模型遵循真实的柱塞-缸孔线接触力动力学行为,并进一步考虑到了接触力作用位置随工况实时动态变化的实际情况。通过实验结果与基于AMESim-ADAMS软件建立的联合仿真模型分布参数法仿真结果的对比,验证了所提出的数学模型。应用实践表明,提出的模型可以方便地应用于对柱塞滑靴组件相关重要动力学参数的全面动态评估及泵结构的动态优化设计。

关键词：斜盘式轴向柱塞泵柱塞滑靴组件动力学模型线接触

固-液-温耦合作用下油液特性对大排量柱塞泵流量脉动的影响

在线全文

学校读者我要写书评

暂无评论

华南理工大学学报（自然科学版） 2023年第9期51卷 44-55页

作者：夏毅敏李正辉谭顺辉刘伟夏士奇中南大学机电工程学院湖南长沙410083 中铁工程装备集团有限公司河南郑州450016 中国铁建重工集团股份有限公司湖南长沙410100

挖掘机、盾构机等大型工程机械工作过程中,由于工况复杂、环境多变,其液压系统动力元件大排量柱塞泵相较于常规柱塞泵存在更大的液压冲击,进而引起较大的流量脉动与压力脉动。为降低大排量柱塞泵在挖掘、盾构等工况下的流量、压力脉动,... 详细信息

挖掘机、盾构机等大型工程机械工作过程中,由于工况复杂、环境多变,其液压系统动力元件大排量柱塞泵相较于常规柱塞泵存在更大的液压冲击,进而引起较大的流量脉动与压力脉动。为降低大排量柱塞泵在挖掘、盾构等工况下的流量、压力脉动,减小油液介质对下游元件的冲击损坏,以及为选择油液介质方法提供理论指导,文中搭建了基于温度场影响的油液动力黏度、密度与体积弹性模量数学模型,在此基础上建立固-液-温耦合作用的柱塞泵数学模型;并使用ADAMS、AMESim软件完成固-液-温耦合作用下750 mL/r柱塞泵联合仿真,得到不同温度影响下柱塞泵流量脉动与压力脉动变化规律;通过整泵试验探究油液温度对柱塞泵压力脉动的影响规律,验证了750 mL/r柱塞泵固-液-温耦合联合仿真模型的正确性。针对油液的3种特性,分别使用正交试验法与单因素分析法考量其对柱塞泵流量脉动率的影响程度和规律。结果表明:柱塞泵出口流量脉动、压力脉动随温度的升高而增大;在设定工况下,油液体积弹性模量对流量脉动率影响占比为97.19%,密度占比为2.03%,动力黏度占比为0.78%;为降低油液特性对柱塞泵出口脉动率的影响,应选择体积弹性模量较大且密度较小的液压油。

关键词：轴向柱塞泵油液特性流量脉动动力学温度场

基于先导压力与主泵压力的挖掘机刷坡工况效率预测

在线全文

学校读者我要写书评

暂无评论

中南大学学报（自然科学版） 2024年第9期55卷 3294-3305页

作者：夏毅敏孙成杰王维陈艳军夏士奇中南大学机电工程学院湖南长沙410083 中联重科股份有限公司湖南长沙410013 中联重科土方机械有限公司湖南长沙410209

针对挖掘机刷坡工况效率获取困难的问题,提出一种基于先导压力与主泵压力的挖掘机效率预测方法。该方法首先以挖掘机实际刷坡作业为研究对象,基于LabVIEW平台完成流量与压力、液压缸位移等原始数据的采集;对原始数据进行基于时间窗口的... 详细信息

针对挖掘机刷坡工况效率获取困难的问题,提出一种基于先导压力与主泵压力的挖掘机效率预测方法。该方法首先以挖掘机实际刷坡作业为研究对象,基于LabVIEW平台完成流量与压力、液压缸位移等原始数据的采集;对原始数据进行基于时间窗口的特征值提取、效率的获取等;然后,建立主成分分析-随机森林模型,包括采用主成分分析理论降低输入数据的维度,提高模型的运算速度与抗过拟合能力,采用随机森林算法建立挖掘机效率预测模型,实现挖掘机效率的精准预测;最后,将随机森林预测模型与支持向量机预测模型和BP神经网络预测模型进行对比,并探究样本数量与时间窗口对模型预测精度的影响、各主成分对挖掘机效率预测的重要程度等。研究结果表明:主成分分析可以有效地将输入数据的维度从18维降至6维,在选定的6个主成分中,挖掘机铲斗下降运动与挖掘机负载波动程度对挖掘机效率预测结果的影响较大;与支持向量机预测模型和BP神经网络预测模型相比,随机森林预测模型的精度更高;在样本数量为0~50 000个、时间窗口为0.05~0.25 s时,建立的基于主成分分析-随机森林算法的预测模型精度随样本数量与时间窗口宽度的增加有所提高,并在样本数量为40 000个、时间窗口宽度为0.1 s时取得最优性能,此时均方根误差为0.029 2。

关键词：效率预测挖掘机随机森林主成分分析

Realization of photonic p-orbital higher-order topological insulators

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

eLight 2023年第1期3卷 230-238页

作者： Yahui Zhang Domenico Bongiovanni Ziteng Wang xiangdong Wang shiqi xia Zhichan Hu Daohong Song Dario Jukic Jingjun Xu Roberto Morandotti Hrvoje Buljan Zhigang Chen The MOE Key Laboratory of Weak‑Light Nonlinear Photonics TEDA Applied Physics Institute and School of PhysicsNankai UniversityTianjin 300457China INRS-EMT 1650 Blvd.Lionel‑BouletVarennesQC J3X 1S2Canada Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006ShanxiChina Faculty of Civil Engineering University of ZagrebA.Kacica Miosica 2610000 ZagrebCroatia Department of Physics Faculty of ScienceUniversity of ZagrebBijenicka C.3210000 ZagrebCroatia

The orbital degrees of freedom play a pivotal role in understanding fundamental phenomena in solid-state materials as well as exotic quantum states of matter including orbital superfluidity and topological *** tremendous efforts in engineering synthetic cold-atom,as well as electronic and photonic lattices to explore orbital physics,thus far high orbitals in an important class of materials,namely,higher-order topological insulators(HOTIs),have not been ***,we demonstrate p-orbital corner states in a photonic HOTI,unveiling their underlying topological invariant,symmetry protection,and nonlinearity-induced dynamical *** a Kagome-type HOTI,we find that the topological protection of p-orbital corner states demands an orbital-hopping symmetry in addition to generalized chiral *** to orbital hybridization,nontrivial topology of the p-orbital HOTI is“hidden”if bulk polarization is used as the topological invariant,but well manifested by the generalized winding *** work opens a pathway for the exploration of intriguing orbital phenomena mediated by higher-band topology applicable to a broad spectrum of systems.

关键词： Higher-band topology Orbital degrees of freedom Generalized chiral symmetry Bulk polarization Winding number Breathing Kagome lattice