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Light(Science & Applications) 2022年第11期11卷 2774-2781页

作者： Xueshi Li Jiantao Ma shunfa liu Peinian Huang Bo Chen Dunzhao Wei Jin liu State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-Sen University510275 GuangzhouChina

Integrated photonics provides unprecedented opportunities to pursue advanced nonlinear light sources with lowpower consumptions and small footprints in a scalable manner,such as microcombs,chip-scale optical parametric oscillators and integrated quantum light sources.Among a variety of nonlinear optical processes,high-efficiency second harmonic generation(SHG)on-chip is particularly appealing and yet challenging.In this work,we present efficient SHG in highly engineerable semi-nonlinear waveguides consisting of electron-beam resist waveguides and thin-film silicon nitride(SiN)/lithium niobate(LN).By carefully designing octave-separating bound states in the continuum(BICs)for the nonlinear interacting waves in such a hybrid structure,we have simultaneously optimized the losses for both fundamental frequency(FF)and second harmonic(SH)waves and achieved modal phasing matching and maximized the nonlinear modal overlap between the FF and SH waves,which results in an experimental conversion efficiency up to 4.05%W^(-1)cm^(-2).Our work provides a versatile and fabrication-friendly platform to explore on-chip nonlinear optical processes with high effciency in the context of nanophotonics and quantum optics.

关键词： nonlinear harmonic lithium

Bright semiconductor single-photon sources pumped by heterogeneously integrated micropillar lasers with electrical injections

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Light(Science & Applications) 2023年第3期12卷 489-496页

作者： Xueshi Li shunfa liu Yuming Wei Jiantao Ma Changkun Song Ying Yu Rongbin Su Wei Geng Haiqiao Ni Hanqing liu Xiangbin Su Zhichuan Niu You-ling Chen Jin liu State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSchool of Electronics and Information TechnologySun Yat-sen University510275GuangzhouChina Hisilicon Research Huawei Technologies Co.Ltd518129ShenzhenChina State Key Laboratory for Superlattice and Microstructures State Key Laboratory on Integrated OptoelectronicsInstitute of SemiconductorsChinese Academy of Sciences100083BeijingChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences100049BeijingChina

The emerging hybrid integrated quantum photonics combines the advantages of different functional components into a single chip to meet the stringent requirements for quantum information processing.Despite the tremendous progress in hybrid integrations of III-V quantum emitters with silicon-based photonic circuits and superconducting single-photon detectors,on-chip optical excitations of quantum emitters via miniaturized lasers towards single-photon sources(SPSs)with low power consumptions,small device footprints,and excellent coherence properties is highly desirable yet illusive.In this work,we present realizations of bright semiconductor SPSs heterogeneously integrated with on-chip electrically-injected microlasers.Different from previous one-by-one transfer printing technique implemented in hybrid quantum dot(QD)photonic devices,multiple deterministically coupled QD-circular Bragg Grating(CBG)SPSs were integrated with electrically-injected micropillar lasers at one time via a potentially scalable transfer printing process assisted by the wide-field photoluminescence(PL)imaging technique.Optically pumped by electrically-injected microlasers,pure single photons are generated with a high-brightness of a count rate of 3.8 M/s and an extraction efficiency of 25.44%.Such a high-brightness is due to the enhancement by the cavity mode of the CBG,which is confirmed by a Purcell factor of 2.5.Our work provides a powerful tool for advancing hybrid integrated quantum photonics in general and boosts the developments for realizing highly-compact,energy-efficient and coherent SPSs in particular.

关键词： pumped quantum photon

Bright and pure single-photons from quantum dots in micropillar cavities under up-converted excitation

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Science Bulletin 2018年第12期63卷 739-742页

作者： Rongling Su shunfa liu Yuming Wei Ying Yu Jin liu Siyuan Yu Xuehua Wang State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySchool of PhysicsSun Yat-sen University Photonics Group Merchant Venturers School of EngineeringUniversity of Bristol

Self-assembled semiconductor quantum dots(QDs)are potentially scalable candidates for solid-state single-photon emitters which deterministically generate one single-photon per excitation.Such on-demand single-photon sources serve as one of the key elements in modern photonic quantum technologies[1].Until very recently,near-optimal QD single-photon sources with simultaneous high degree of brightness,single-photon purity and indistin-

关键词：光子量点半导体候选人可伸缩

基于权重分摊的LeNet-5卷积神经网络防御策略

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测控技术 2024年第6期43卷 33-39页

作者：陈顺发刘芬天津职业技术师范大学电子工程学院天津300222

随着神经网络在自动驾驶、医疗诊断等关键领域的应用不断深入,如何确保神经网络的鲁棒性和安全性已成为当前研究的热点和挑战。在对抗攻击、数据中毒攻击、后门攻击等众多攻击方式中,随机翻转攻击是一种对安全性影响极大的攻击,其通过... 详细信息

随着神经网络在自动驾驶、医疗诊断等关键领域的应用不断深入,如何确保神经网络的鲁棒性和安全性已成为当前研究的热点和挑战。在对抗攻击、数据中毒攻击、后门攻击等众多攻击方式中,随机翻转攻击是一种对安全性影响极大的攻击,其通过改变模型内部的权重参数来攻击网络,以降低网络性能。为应对此攻击方式,研究了一种基于权重分摊的防御策略。通过计算和分析权重的梯度来确定关键神经元,并为这些神经元添加冗余结构,使错误的权重最终被稀释,以提高模型的容错能力。为了验证这一防御策略,以LeNet-5模型为实验对象进行实验。实验表明,在相同的攻击条件下,经过防御后的模型相较于原始LeNet-5模型,容错精度提升了6.5%,相较于Inception-LeNet-5模型在全连接层上容错精度提升了1.9%。

关键词：神经网络防御权重分摊 LeNet-5 容错

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黄河流域旅游—生态系统脆弱性时空演变特征及影响因素

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西南大学学报（自然科学版） 2024年第4期46卷 92-103页

作者：曹开军李如雪龙顺发刘勤新疆大学旅游学院乌鲁木齐830046 新疆大学新疆历史文化旅游可持续发展重点实验室乌鲁木齐830046

科学评估区域脆弱性状况,降低系统脆弱性是推动地区高质量发展的依据.以黄河流域63个地级市为研究对象,基于压力—状态—响应(PSR)模型构建旅游—生态系统脆弱性综合评价指标体系,采用熵值法、综合指数法、空间自相关、障碍度模型分析2... 详细信息

科学评估区域脆弱性状况,降低系统脆弱性是推动地区高质量发展的依据.以黄河流域63个地级市为研究对象,基于压力—状态—响应(PSR)模型构建旅游—生态系统脆弱性综合评价指标体系,采用熵值法、综合指数法、空间自相关、障碍度模型分析2006、2010、2015、2019及2020年黄河流域旅游—生态系统的脆弱性时空分布特征及影响因素.结果表明:①研究区旅游—生态系统脆弱性指数先下降后上升,总体处于波动下降趋势,脆弱等级处于中度脆弱水平;旅游子系统脆弱性呈上升后下降趋势,生态子系统脆弱性呈下降趋势;②空间分布上脆弱性呈由西向东逐渐升高的变化趋势,综合系统及各子系统脆弱性空间差异显著,空间集聚态势明显,“高—高”聚集地区空间集聚效应增强,“低—低”聚集地区空间范围增大;③影响系统脆弱性降低的最大障碍因素由建成区绿化覆盖率转变为旅游者与当地居民比,旅游经济密度、空气质量优良率等要素也是阻碍系统脆弱性降低的主要影响因素.

关键词：黄河流域旅游—生态系统脆弱性 PSR模型熵值法障碍度

新疆县市旅游城镇化响应的空间格局演变及影响因素

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生态经济 2024年第2期40卷 150-155页

作者：刘勤曹开军程咏春龙顺发新疆历史文化旅游可持续发展重点实验室新疆乌鲁木齐830046 新疆大学旅游学院新疆乌鲁木齐830046 新疆师范大学外国语学院新疆乌鲁木齐830017

旅游业引导的城镇化建设不仅可以有效挖掘城镇化建设潜力,也成为驱动经济增长的新型机制。以新疆85个县市为研究对象,测度2006—2018年各县市的旅游城镇化响应系数,采用空间自相关技术分析其时空格局演变特征,并利用地理探测器探测旅游... 详细信息

旅游业引导的城镇化建设不仅可以有效挖掘城镇化建设潜力,也成为驱动经济增长的新型机制。以新疆85个县市为研究对象,测度2006—2018年各县市的旅游城镇化响应系数,采用空间自相关技术分析其时空格局演变特征,并利用地理探测器探测旅游城镇化响应系数的影响因素。结果表明:(1)旅游产业对新疆各县市城镇化的推动作用不断加强,总体呈“北疆>东疆>南疆”的特点,各县市之间旅游城镇化响应强度的空间差异逐渐缩小。(2)新疆各县市旅游城镇化响应均具有显著的正向空间自相关性,旅游城镇化响应强度的空间集聚现象明显。(3)旅游城镇化响应影响因素的解释力从大到小依次为:旅游产业集聚、地理区位、旅游人次、旅游资源禀赋、产业结构。

关键词：旅游城镇化响应时空演变影响因素新疆

Dual-resonance enhanced quantum light-matter interactions in deterministically coupled quantum-dot-micropillars

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Light(Science & Applications) 2021年第9期10卷 1680-1686页

作者： shunfa liu Yuming Wei Xueshi Li Ying Yu Jin liu Siyuan Yu Xuehua Wang State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSchool of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou510275China Photonics Group Merchant Venturers School of EngineeringUniversity of BristolBristolBS81UBUK

Optical microcavities have widely been employed to enhance either the optical excitation or the photon emission processes for boosting light-matter interactions at the nanoscale.When both the excitation and emission processes are simultaneously facilitated by the optical resonances provided by the microcavities,as referred to the dual-resonance condition in this article,the performances of many nanophotonic devices approach to the optima.In this work,we present versatile accessing of dual-resonance conditions in deterministically coupled quantum-dot(QD)-micropillars,which enables emission from neutral exciton(X)—charged exciton(CX)transition with improved single-photon purity.In addition,the rarely observed up-converted single-photon emission process is achieved under dual-resonance conditions.We further exploit the vectorial nature of the high-order cavity modes to significantly improve the excitation efficiency under the dual-resonance condition.The dual-resonance enhanced light-matter interactions in the quantum regime provide a viable path for developing integrated quantum photonic devices based on cavity quantum electrodynamics(QED)effect,e.g.,highly efficient quantum light sources and quantum logical gates.

关键词： quantum resonance excitation

Pt/Mo2C heteronanosheets for superior hydrogen evolution reaction

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Journal of Energy Chemistry 2020年第8期29卷 317-323,I0011页

作者： Zhao liu Jing Li Shiji Xue shunfa Zhou Konggang Qu Ying Li Weiwei Cai Sustainable Energy Laboratory Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430074HubeiChina Shandong Provincial Key Laboratory/Collaborative Innovation Center of Chemical Energy Storage&Novel Cell Technology Liaocheng UniversityLiaocheng 252059ShandongChina Research Institute for New Materials Technology Chongqing University of Arts and SciencesChongqing 402160China Zhejiang Institute China University of GeosciencesHangzhou 311305ZhejiangChina

One of the most primary challenges to achieve large-scale hydrogen generation from water electrolysis is the sluggish kinetics and noble metal dependence of cathodic hydrogen evolution reaction(HER).By considering the excellent water dissociation catalytic activity of Mo2C, abundant Pt/Mo2C interfaces were facilely engineered via galvanic replacement(gr) by using Mo/Mo2C nanosheets as self-sacrificed templates to alter the alkaline HER mechanism on Pt based catalyst. The rational designed interface-rich gr-Pt/Mo2C catalyst exhibited excellent activity with the overpotential to drive 10 mA/cm2 current density decreased by 18.5 mV compared with the commercial Pt/C catalyst. 34.3 mV/dec Tafel slope confirms the Volmer-Tafel HER route on gr-Pt/Mo2C in alkaline condition. Platinum utilization is calculated to be improved by 9.7 times by considered the low Pt loading in the gr-Pt/Mo2C catalyst. With its satisfied stability, the scalable gr-Pt/Mo2C catalyst shows promising application potential in industrial electrolysis systems.

关键词： Hydrogen evolution reaction Heteronanosheet Galvanic replacement Pt/Mo2C interface Pt utilization

Using nerve segment insert grafting to reconstruct neural pathways of brain-derived paralysis

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Translational Neuroscience and Clinics 2017年第4期3卷 188-195页

作者： Wenbin Ding Shaocheng Zhang Zhuo Wang Lin Chen Chuansen Zhang Ping Huang shunfa liu Laiqing Sun Yuhai Ma Jun Yang Fei Huang Chengjing Xue Yanxue Zhong Lei Yin Yongtai Pan Dajiang Wu Department of Orthopaedics Changhai Hospitalthe Naval Medical University Department of Neurosurgery Yuquan HospitalTsinghua University Department of Anatomy the Second Military Medical University Department of Orthopaedics Jingmen No.2 People’s Hospital Department of Orthopaedics Qinhuangdao Workers’ Hospital Department of Orthopaedics Tangshan No.2 Hospital Department of Orthopaedics Jiaxing Armed Police Force Hospital Department of Neurosurgery Yantai HospitalBinzhou Medical University Department of Anatomy Binzhou Medical University Department of Neurosurgery North China University of Science and Technology Affiliated Hospital Department of Orthopaedics Tengzhou Central People’s Hospital Department of Orthopaedics Jiangsu Armed Police General Hospital Department of Orthopaedics the 180th Hospital of PLA

Since 1992,task groups have used free nerve auto grafts to bridge partially transected nerves from the dominant area of the normal cerebral cortex to nerves that innervate spastic muscles from a diseased cerebral cortex,using transplanting sutures to alleviate the muscle spasm of cerebral palsy caused by different diseases. This has facilitated rebuilding of some of its neurological function. In this study,80 such patients were followed up,including 20 patients with traumatic brain injury,32 patients with stroke,and 28 pediatric patients with cerebral palsy. After postoperative follow-up of 3 to 21 years,the efficacy rate of this operation was 100% and the excellent and good spasm relief rate was 82.5%.

关键词： cerebral trauma child cerebral pals functional reconstruction graft surgery hemiplegic paralysis nerve segment transplantation spastic paralysis stroke

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次镜支撑结构的力学性能分析

仪器仪表学报 2007年第5期28卷 859-864页

作者：梁文科刘顺发中国科学院光电技术研究所中国科学院研究生院北京 100039

次镜支撑结构性能的好坏直接影响光学系统的成像质量。针对几种典型的支撑结构,利用I-DEAD软件建立有限元模型,进行动力学分析计算。在比较典型结构的基础上,改进得到了2种新型偏置结构,即三翼偏置支撑结构和新型的四翼偏置支撑结构。... 详细信息

次镜支撑结构性能的好坏直接影响光学系统的成像质量。针对几种典型的支撑结构,利用I-DEAD软件建立有限元模型,进行动力学分析计算。在比较典型结构的基础上,改进得到了2种新型偏置结构,即三翼偏置支撑结构和新型的四翼偏置支撑结构。通过分析表明,在同等条件下,2种新型结构能更大程度地减小遮拦比,提高光学系统质量;或是说,在遮拦比一致以及偏置距离相同的条件下,2种新型支撑结构的一阶谐振频率均大于传统的四翼偏置支撑结构,稳定性能更好,更适用于大口径的光学系统。

关键词：光学系统支撑结构固有频率有限元分析