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End-group modulation of phenazine based non-fullerene acceptors for efficient organic solar cells with high open-circuit voltage
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作者 yahui zhang Yafeng Li +7 位作者 Ruixiang Peng Yi Qiu Jingyu Shi Zhenyu Chen Jinfeng Ge Cuifen zhang Zheng Tang Ziyi Ge 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期461-468,I0011,共9页
Phenazine-based non-fullerene acceptors(NFAs)have demonstrated great potential in improving the power conversion efficiency(PCE)of organic solar cells(OSCs).Halogenation is known to be an effective strategy for increa... Phenazine-based non-fullerene acceptors(NFAs)have demonstrated great potential in improving the power conversion efficiency(PCE)of organic solar cells(OSCs).Halogenation is known to be an effective strategy for increasing optical absorption,refining energy levels,and improving molecular packing in organic semiconductors.Herein,a series of NFAs(Pz IC-4H,Pz IC-4F,Pz IC-4Cl,Pz IC-2Br)with phenazine as the central core and with/without halogen-substituted(dicyanomethylidene)-indan-1-one(IC)as the electron-accepting end group were synthesized,and the effect of end group matched phenazine central unit on the photovoltaic performance was systematically studied.Synergetic photophysical and morphological analyses revealed that the PM6:Pz IC-4F blend involves efficient exciton dissociation,higher charge collection and transfer rates,better crystallinity,and optimal phase separation.Therefore,OSCs based on PM6:Pz IC-4F as the active layer exhibited a PCE of 16.48%with an open circuit voltage(Voc)and energy loss of 0.880 V and 0.53 e V,respectively.Accordingly,this work demonstrated a promising approach by designing phenazine-based NFAs for achieving high-performance OSCs. 展开更多
关键词 Organic solar cells Non-fullerene acceptor PHENAZINE Central core End group
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Digital Twin Modeling and Simulation Optimization of Transmission Front and Middle Case Assembly Line
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作者 Xianfeng Cao Meihua Yao +2 位作者 yahui zhang Xiaofeng Hu Chuanxun Wu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期3233-3253,共21页
As the take-off of China’s macro economy,as well as the rapid development of infrastructure construction,real estate industry,and highway logistics transportation industry,the demand for heavy vehicles is increasing ... As the take-off of China’s macro economy,as well as the rapid development of infrastructure construction,real estate industry,and highway logistics transportation industry,the demand for heavy vehicles is increasing rapidly,the competition is becoming increasingly fierce,and the digital transformation of the production line is imminent.As one of themost important components of heavy vehicles,the transmission front andmiddle case assembly lines have a high degree of automation,which can be used as a pilot for the digital transformation of production.To ensure the visualization of digital twins(DT),consistent control logic,and real-time data interaction,this paper proposes an experimental digital twin modeling method for the transmission front and middle case assembly line.Firstly,theDT-based systemarchitecture is designed,and theDT model is created by constructing the visualization model,logic model,and data model of the assembly line.Then,a simulation experiment is carried out in a virtual space to analyze the existing problems in the current assembly line.Eventually,some improvement strategies are proposed and the effectiveness is verified by a new simulation experiment. 展开更多
关键词 Transmission front and middle case assembly line digital twin(DT) simulating optimization intelligent manufacturing
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Changes in human settlement environments and their drivers in valley cities located in arid and semi-arid regions:A case study of Lanzhou in Western China
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作者 Rong Zhu YouYan Jiang +1 位作者 Bo Wang yahui zhang 《Research in Cold and Arid Regions》 CSCD 2024年第3期149-158,共10页
Development of urban human settlement environments(HSEs)is an integral part of promoting high-quality and sustainable regional development and constructing a beautiful China.The city of Lanzhou,located at the geometri... Development of urban human settlement environments(HSEs)is an integral part of promoting high-quality and sustainable regional development and constructing a beautiful China.The city of Lanzhou,located at the geometric center of China,is the only provincial capital traversed by the Yellow River.Given the constraints posed by the valley topography and the need for economic development,the development of this HSE,which is located within an arid region,poses considerable challenges.Evidently,an understanding of the evolution of HSEs and drivers of changes in them contributes to high-quality,sustainable urban development in arid and semi-arid regions.An analytical model was developed using the parameters of relief degree of land surface,human comfort days,the land cover index,nighttime light index,and precipitation.This model was used in combination with population density and the gross domestic product to analyze the spatial distribution of Lanzhou's HSE and its drivers.The results showed that landscapes in Lanzhou underwent significant changes between 2000 and 2022,with an increase in building-up land(+0.946%),cultivated land(+0.134%),and forest land(+0.018%)and a decrease in grassland(-1.10%).There was significant outward expansion of the main urban zone of Lanzhou and of various county towns,with the increase in building-up land being most prominent.During this period,there were significant changes in the periphery of the core urban area and county towns in Lanzhou,with decreases moving from the urban center(the highest value)to the surrounding areas(Yongdeng County had the lowest value).The correlation between the HSE and population density grew stronger in Anning and Chengguan Districts but became weaker in Xigu and Qilihe Districts.Spatiotemporal variations in the HSE were primarily caused by climate change,followed by human activities,and were also influenced by the valley topography.Overall,the spatial distribution of population density and the HSE in Lanzhou demonstrated good consistency under the in-fluence of economic development and urbanization. 展开更多
关键词 Human settlement environment Vegetation index Nighttime light index Human comfort days
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Prediction model of surrounding rock deformation in doublecontinuous-arch tunnel based on the ABC-WNN
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作者 yahui zhang 《Railway Sciences》 2024年第6期717-730,共14页
Purpose–The wavelet neural network(WNN)has the drawbacks of slow convergence speed and easy falling into local optima in data prediction.Although the artificial bee colony(ABC)algorithm has strong global optimization... Purpose–The wavelet neural network(WNN)has the drawbacks of slow convergence speed and easy falling into local optima in data prediction.Although the artificial bee colony(ABC)algorithm has strong global optimization ability and fast convergence speed,it also has the drawbacks of slow speed while finding the optimal solution and weak optimization ability in the later stage.Design/methodology/approach–This article uses an ABC algorithm to optimize the WNN and establishes an ABC-WNN analysis model.Based on the example of the Jinan Yuhan underground tunnel project,the deformation of the surrounding rock of the double-arch tunnel crossing the fault fracture zone is predicted and analyzed,and the analysis results are compared with the actual detection amount.Findings–The comparison results show that the predicted values of the ABC-WNN model have a high degree of fitting with the actual engineering data,with a maximum relative error of only 4.73%.On this basis,the results show that the statistical features of ABC-WNN are the lowest,with the errors at 0.566 and 0.573,compared with the single back propagation(BP)neural network model and WNN model.Therefore,it can be derived that the ABC-WNN model has higher prediction accuracy,better computational stability and faster convergence speed for deformation.Originality/value–This article uses firstly the ABC-WNN for the deformation analysis of double-arch tunnels.This attempt laid the foundation for artificial intelligence prediction in deformation analysis of multiarch tunnels and small clearance tunnels.It can provide a new and effective way for deformation prediction in similar projects. 展开更多
关键词 Double arch tunnel Deformation prediction Artificial bee colonies Surrounding rock Wavelet neural network
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Multiscale evolution mechanism of sandstone under wet-dry cycles of deionized water:From molecular scale to macroscopic scale 被引量:3
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作者 Jie Meng Changdong Li +5 位作者 Jia-Qing Zhou Zihan zhang Shengyi Yan yahui zhang Dewei Huang Guihua Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第5期1171-1185,共15页
Water is the most abundant molecule found on the earth’s surface and is a key factor in multiscale rock destruction.However,given the fine-grained nature of rock and the complexity of its internal structure,the micro... Water is the most abundant molecule found on the earth’s surface and is a key factor in multiscale rock destruction.However,given the fine-grained nature of rock and the complexity of its internal structure,the microstructural evolution of rock under the action of water has not yet been elucidated in detail,and little is understood about the relationship between the rock structure and solideliquid unit.A variety of techniques were used in this study to track the mechanical properties,pore and crack characteristics,and mineral structure degradation characteristics of sandstone at different stages under the action of deionized water,and the evolution mechanisms of the microstructure were analyzed at the molecular scale.The results showed that during the watererock interaction process,water was adsorbed onto the surface of dolomite minerals and the hydrophilic surface of clay minerals,forming a high-density hydrogen bond network.However,different mineral surface structures had different water adsorption structures,resulting in the strain of the dense clay mineral aggregates under expansion action.Stress concentrated at crack tips under the capillary force of dolomite minerals(very weak dolomite dissolution).These effects resulted in a substantial increase in the number of small pores and enhancements in poreecrack connectivity,and the rock strength exhibited varying degrees of decline at different stages of wet-dry cycles.In general,the results of this paper will help to further elucidate the internal connections between molecular-scale and macroscale processes in rock science. 展开更多
关键词 Rock structure Watererock interaction Multiscale evolution Adsorption structure Hydrogen bond
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Photonic integrated neuro-synaptic core for convolutional spiking neural network 被引量:2
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作者 Shuiying Xiang Yuechun Shi +14 位作者 yahui zhang Xingxing Guo Ling Zheng Yanan Han Yuna zhang Ziwei Song Dianzhuang Zheng Tao zhang Hailing Wang Xiaojun Zhu Xiangfei Chen Min Qiu Yichen Shen Wanhua Zheng Yue Hao 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第11期29-42,共14页
Neuromorphic photonic computing has emerged as a competitive computing paradigm to overcome the bottlenecks of the von-Neumann architecture.Linear weighting and nonlinear spike activation are two fundamental functions... Neuromorphic photonic computing has emerged as a competitive computing paradigm to overcome the bottlenecks of the von-Neumann architecture.Linear weighting and nonlinear spike activation are two fundamental functions of a photonic spiking neural network(PSNN).However,they are separately implemented with different photonic materials and devices,hindering the large-scale integration of PSNN.Here,we propose,fabricate and experimentally demonstrate a photonic neuro-synaptic chip enabling the simultaneous implementation of linear weighting and nonlinear spike activation based on a distributed feedback(DFB)laser with a saturable absorber(DFB-SA).A prototypical system is experimentally constructed to demonstrate the parallel weighted function and nonlinear spike activation.Furthermore,a fourchannel DFB-SA laser array is fabricated for realizing matrix convolution of a spiking convolutional neural network,achieving a recognition accuracy of 87%for the MNIST dataset.The fabricated neuro-synaptic chip offers a fundamental building block to construct the large-scale integrated PSNN chip. 展开更多
关键词 neuromorphic computation photonic spiking neuron photonic integrated DFB-SA array convolutional spiking neural network
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Pattern recognition in multi-synaptic photonic spiking neural networks based on a DFB-SA chip 被引量:2
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作者 Yanan Han Shuiying Xiang +6 位作者 Ziwei Song Shuang Gao Xingxing Guo yahui zhang Yuechun Shi Xiangfei Chen Yue Hao 《Opto-Electronic Science》 2023年第9期1-10,共10页
Spiking neural networks(SNNs)utilize brain-like spatiotemporal spike encoding for simulating brain functions.Photonic SNN offers an ultrahigh speed and power efficiency platform for implementing high-performance neuro... Spiking neural networks(SNNs)utilize brain-like spatiotemporal spike encoding for simulating brain functions.Photonic SNN offers an ultrahigh speed and power efficiency platform for implementing high-performance neuromorphic computing.Here,we proposed a multi-synaptic photonic SNN,combining the modified remote supervised learning with delayweight co-training to achieve pattern classification.The impact of multi-synaptic connections and the robustness of the network were investigated through numerical simulations.In addition,the collaborative computing of algorithm and hardware was demonstrated based on a fabricated integrated distributed feedback laser with a saturable absorber(DFB-SA),where 10 different noisy digital patterns were successfully classified.A functional photonic SNN that far exceeds the scale limit of hardware integration was achieved based on time-division multiplexing,demonstrating the capability of hardware-algorithm co-computation. 展开更多
关键词 photonic spiking neural network fabricated DFB-SA laser chip multi-synaptic connection optical computing
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A review:Photonics devices,architectures,and algorithms for optical neural computing 被引量:13
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作者 Shuiying Xiang Yanan Han +15 位作者 Ziwei Song Xingxing Guo yahui zhang Zhenxing Ren Suhong Wang Yuanting Ma Weiwen Zou Bowen Ma Shaofu Xu Jianji Dong Hailong Zhou Quansheng Ren Tao Deng Yan Liu Genquan Han Yue Hao 《Journal of Semiconductors》 EI CAS CSCD 2021年第2期64-79,共16页
The explosive growth of data and information has motivated various emerging non-von Neumann computational approaches in the More-than-Moore era.Photonics neuromorphic computing has attracted lots of attention due to t... The explosive growth of data and information has motivated various emerging non-von Neumann computational approaches in the More-than-Moore era.Photonics neuromorphic computing has attracted lots of attention due to the fascinating advantages such as high speed,wide bandwidth,and massive parallelism.Here,we offer a review on the optical neural computing in our research groups at the device and system levels.The photonics neuron and photonics synapse plasticity are presented.In addition,we introduce several optical neural computing architectures and algorithms including photonic spiking neural network,photonic convolutional neural network,photonic matrix computation,photonic reservoir computing,and photonic reinforcement learning.Finally,we summarize the major challenges faced by photonic neuromorphic computing,and propose promising solutions and perspectives. 展开更多
关键词 photonics neuron photonic STDP photonic spiking neural network optical reservoir computing optical convolutional neural network neuromorphic photonics
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Identifying the leucogranites in the Ailaoshan-Red River shear zone:Constraints on the timing of the southeastward expansion of the Tibetan Plateau 被引量:2
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作者 Xiaohu He Shucheng Tan +4 位作者 Jiaxi Zhou Zheng Liu Zhifang Zhao Siqi Yang yahui zhang 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第3期765-781,共17页
The uplift of the Tibetan Plateau significantly affected the global climate system.However,the timing of its uplift and the formation of its vast expanse are poorly understood.The occurrence of two types of leucograni... The uplift of the Tibetan Plateau significantly affected the global climate system.However,the timing of its uplift and the formation of its vast expanse are poorly understood.The occurrence of two types of leucogranites(the two-mica leucogranites and garnet-bearing leucogranites) identified in the Ailaoshan-Red River(ASRR) shear zone suggests an extension event in the southeastern Tibetan Plateau.The age of these leucogranites could be used to constrain the timing of uplift and southeastward expansion of the plateau.Petrography,geochronology and geochemistry investigations,including Sr-Nd isotope analysis,were conducted on the two-mica leucogranites and garnet-bearing leucogranites from the ASRR shear zone.LA-ICP-MS zircon U-Pb dating indicates that these rocks were emplaced at ~27 Ma,implying that the Tibetan Plateau had already achieved maximum uplift prior to the late Oligocene.It subsequently started to expand southeastward as a result of crustal flow.Compared to classic metapelite-derived leucogranites from Himalaya,the two-mica leucogranites show high K_2 O/Na_2 O(1.31-1.92),low Rb/Sr,CaO,lower ^(87)Sr/^(86)Sr ratios(0.7089-0.7164) and higher ε_(Nd)(t)(-8.83 to-3.10).This whole-rock geochemical characteristics likely indicates a mixing source origin,composed predominantly of amphibolite with subordinated metapelite,which is also evidenced by ^(87)Sr/^(86)Sr vs.ε_(Nd)(t) diagram.However,The garnetbearing leucogranites with high SiO_2 contents(72.25-74.12 wt.%) have high initial ^(87)Sr/^(86)Sr ratios(0.7332-0.7535) and low ε_(Nd)(t)(-16.36 to 18.98),indicating that they are derived from the source comprised of metapelite and results of fluexed muscovite melting under lower crustal level,which is also evidenced by the Rb-Sr-Ba systematics.These leucogranites formed from partial melting of the thickened lower crust,which resulted in the formation of granitic melt that weakened the crust.The weakened crust aided the left-lateral strikeslip movement of the ASRR shear zone,triggering the escape of the Indochina terrane in the southeastern Tibetan Plateau during the late Oligocene. 展开更多
关键词 LEUCOGRANITES CRUSTAL flow Southeastward EXPANSION Ailaoshan-red river shear zone TIBETAN PLATEAU
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Beam Approximation for Dynamic Analysis of Launch Vehicles Modelled as Stiffened Cylindrical Shells 被引量:2
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作者 Siyang Piao Huajiang Ouyang yahui zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第2期571-591,共21页
A beam approximation method for dynamic analysis of launch vehicles modelled as stiffened cylindrical shells is proposed.Firstly,an initial beam model of the stiffened cylindrical shell is established based on the cro... A beam approximation method for dynamic analysis of launch vehicles modelled as stiffened cylindrical shells is proposed.Firstly,an initial beam model of the stiffened cylindrical shell is established based on the cross-sectional area equivalence principle that represents the shell skin and its longitudinal ribs as a beam with annular cross-section,and the circumferential ribs as lumped masses at the nodes of the beam elements.Then,a fine finite element model(FE model)of the stiffened cylindrical shell is constructed and a modal analysis is carried out.Finally,the initial beam model is improved through model updating against the natural frequencies and mode shapes of the fine FE model of the shell.To facilitate the comparison between the mode shapes of the fine FE model of the stiffened shell and the equivalent beam model,a weighted nodal displacement coupling relationship is introduced.To prevent the design parameters used in model updating from converging to incorrect values,a pre-model updating procedure is added before the proper model updating.The results of two examples demonstrate that the beam approximation method presented in this paper can build equivalent beam models of stiffened cylindrical shells which can reflect the global longitudinal,lateral and torsional vibration characteristics very well in terms of the natural frequencies. 展开更多
关键词 Finite element method model updating stiffened shell beam approximation model reduction.
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Recycling of waste aluminum scraps to fabricate sulfidated zero-valent iron-aluminum particles for enhanced chromate removal
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作者 yahui zhang Liguo zhang +5 位作者 Jiajia Zeng Shuqun Xu Jianyu Pan Wenzhuo Huang Jianliang Sun Feng Jiang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第4期650-659,共10页
Massive waste aluminum scraps produced from the spent aluminum products have high electron capacity and can be recycled as an attractive alternative to materials based on zerovalent iron(Fe^(0))for the removal of oxid... Massive waste aluminum scraps produced from the spent aluminum products have high electron capacity and can be recycled as an attractive alternative to materials based on zerovalent iron(Fe^(0))for the removal of oxidative contaminants from wastewater.This study thus proposed an approach to fabricate micron-sized sulfidated zero-valent iron-aluminum particles(S-Al^(0)@Fe^(0))with high reactivity,electron selectivity and capacity using recycled waste aluminum scraps.S-Al^(0)@Fe^(0)with a three-layer structure contained zero-valent aluminum(Al^(0))core,Fe^(0) middle layer and iron sulfide(FeS)shell.The rates of chromate(Cr(Ⅵ))removal by S-Al^(0)@Fe^(0)at pH 5.0-9.0 were 1.6-5.9 times greater than that by sulfidated zero-valent iron(S-Fe^(0)).The Cr(Ⅵ)removal capacity of S-Al^(0)@Fe^(0)was 8.2-,11.3-and 46.9-fold greater than those of S-Fe0,zero-valent iron-aluminum(Al^(0)-Fe^(0))and Fe^(0),respectively.The chemical cost of S-Al^(0)@Fe^(0) for the equivalent Cr(Ⅵ)removal was 78.5%lower than that of S-Fe^(0).Negligible release of soluble aluminum during the Cr(Ⅵ)removal was observed.The significant enhancement in the reactivity and capacity of S-Al^(0)@Fe^(0)was partially ascribed to the higher reactivity and electron density of the Al0core than Fe^(0).More importantly,S-Al^(0)@Fe^(0) served as an electric cell to harness the persistent and selective electron transfer from the Al^(0)-Fe^(0) core to Cr(Ⅵ)at the surface via coupling Fe^(0)-Fe^(2+)-Fe^(3+)redox cycles,resulting in a higher electron utilization efficiency.Therefore,S-Al^(0)@Fe^(0) fabricated using recycled waste aluminum scraps can be a cost-effective and environmentally-friendly alternative to S-Fe^(0) for the enhanced removal of oxidative contaminants in industrial wastewater. 展开更多
关键词 Recycled waste aluminum scraps Oxidative contaminants Cr(Ⅵ)reduction Sulfidated Al^(0)@Fe^(0)particle Electron transfer
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Experimental and numerical studies on buckling and post-buckling behavior of T-stiffened variable stiffness panels
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作者 Yan HUANG yahui zhang +3 位作者 Bin KONG Jiefei GU Zhe WANG Puhui CHEN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第10期459-470,共12页
Currently,experimental research on variable stiffness design mainly focuses on laminates.To ensure adaptability in practical application,it is imperative to conduct a systematic study on stiffened variable stiffness s... Currently,experimental research on variable stiffness design mainly focuses on laminates.To ensure adaptability in practical application,it is imperative to conduct a systematic study on stiffened variable stiffness structures,including design,manufacture,experiment,and simulation.Based on the minimum curvature radius and process schemes,two types of T-stiffened panels were designed and manufactured.Uniaxial compression tests have been carried out and the results indicate that the buckling load of variable stiffness specimens is increased by 26.0%,while the failure load is decreased by 19.6%.The influence mechanism of variable stiffness design on the buckling and failure behavior of T-stiffened panels was explicated by numerical analysis.The primary reason for the reduced strength is the significantly increased load bearing ratio of stiffeners.As experimental investigations of stiffened variable stiffness structures are very rare,this study can be considered a reference for future work. 展开更多
关键词 Variable stiffness composite BUCKLING POST-BUCKLING Finite element method Stiffened panels
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The 3^(rd) Xihua Chemistry and Biomedicine Forum
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作者 yahui zhang Zhouyu Wang +1 位作者 Leyong Wang Xiaoqi Yu 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第2期1-2,共2页
Serious diseases,particularly cancer,consistently pose significant threats to both national health and economic development[1].The cancer diagnosis methods such as fluorescent probes[2,3],as well as treatment techniqu... Serious diseases,particularly cancer,consistently pose significant threats to both national health and economic development[1].The cancer diagnosis methods such as fluorescent probes[2,3],as well as treatment techniques including photodynamic treatments[4]and targeted drugs[5]have attracted much attention in recent years.The development and practical application of these methods have become focal points within research works.Based on this,the 3rd Xihua Chemistry and Biomedicine Forum(XHCBF)was successfully convened by Xihua University in Chengdu from 3 to 6 July,2023. 展开更多
关键词 DIAGNOSIS DRUGS TREATMENT FORUM
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Short-term prediction for chaotic time series based on photonic reservoir computing using VCSEL with a feedback loop
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作者 XINGXING GUO HANXU ZHOU +5 位作者 SHUIYING XIANG QIAN YU yahui zhang YANAN HAN TAO WANG YUE HAO 《Photonics Research》 SCIE EI CAS CSCD 2024年第6期1222-1230,共9页
Chaos,occurring in a deterministic system,has permeated various fields such as mathematics,physics,and life science.Consequently,the prediction of chaotic time series has received widespread attention and made signifi... Chaos,occurring in a deterministic system,has permeated various fields such as mathematics,physics,and life science.Consequently,the prediction of chaotic time series has received widespread attention and made signifi-cant progress.However,many problems,such as high computational complexity and difficulty in hardware im-plementation,could not be solved by existing schemes.To overcome the problems,we employ the chaotic system of a vertical-cavity surface-emitting laser(VCSEL)mutual coupling network to generate chaotic time series through optical system simulation and experimentation in this paper.Furthermore,a photonic reservoir com-puting based on VCSEL,along with a feedback loop,is proposed for the short-term prediction of the chaotic time series.The relationship between the prediction difficulty of the reservoir computing(RC)system and the differ-ence in complexity of the chaotic time series has been studied with emphasis.Additionally,the attention coefficient of injection strength and feedback strength,prediction duration,and other factors on system perfor-mance are considered in both simulation and experiment.The use of the RC system to predict the chaotic time series generated by actual chaotic systems is significant for expanding the practical application scenarios of the RC. 展开更多
关键词 LOOP CHAOTIC PREDICTION
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Realization of photonic p-orbital higher-order topological insulators 被引量:5
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作者 yahui zhang Domenico Bongiovanni +9 位作者 Ziteng Wang Xiangdong Wang Shiqi Xia Zhichan Hu Daohong Song Dario Jukic Jingjun Xu Roberto Morandotti Hrvoje Buljan Zhigang Chen 《eLight》 2023年第1期230-238,共9页
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 semimetals.... 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 semimetals.Despite 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 realized.Here,we demonstrate p-orbital corner states in a photonic HOTI,unveiling their underlying topological invariant,symmetry protection,and nonlinearity-induced dynamical rotation.In 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 symmetry.Due 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 number.Our work opens a pathway for the exploration of intriguing orbital phenomena mediated by higher-band topology applicable to a broad spectrum of systems. 展开更多
关键词 Higher-band topology Orbital degrees of freedom Generalized chiral symmetry Bulk polarization Winding number Breathing Kagome lattice
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Experimental demonstration of coherent photonic neural computing based on a Fabry–Perot laser with a saturable absorber 被引量:3
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作者 DIANZHUANG ZHENG SHUIYING XIANG +7 位作者 XINGXING GUO yahui zhang BILING GU HONGJI WANG ZHENZHEN XU XIAOJUN ZHU YUECHUN SHI YUE HAO 《Photonics Research》 SCIE EI CAS CSCD 2023年第1期65-71,共7页
As Moore’s law has reached its limits,it is becoming increasingly difficult for traditional computing architectures to meet the demands of continued growth in computing power.Photonic neural computing has become a pr... As Moore’s law has reached its limits,it is becoming increasingly difficult for traditional computing architectures to meet the demands of continued growth in computing power.Photonic neural computing has become a promising approach to overcome the von Neuman bottleneck.However,while photonic neural networks are good at linear computing,it is difficult to achieve nonlinear computing.Here,we propose and experimentally demonstrate a coherent photonic spiking neural network consisting of Mach–Zehnder modulators(MZMs)as the synapse and an integrated quantum-well Fabry–Perot laser with a saturable absorber(FP-SA)as the photonic spiking neuron.Both linear computation and nonlinear computation are realized in the experiment.In such a coherent architecture,two presynaptic signals are modulated and weighted with two intensity modulation MZMs through the same optical carrier.The nonlinear neuron-like dynamics including temporal integration,threshold,and refractory period are successfully demonstrated.Besides,the effects of frequency detuning on the nonlinear neuron-like dynamics are also explored,and the frequency detuning condition is revealed.The proposed hardware architecture plays a foundational role in constructing a large-scale coherent photonic spiking neural network. 展开更多
关键词 tuning LASER neural
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Photonic integrated spiking neuron chip based on a self-pulsating DFB laser with a saturable absorber 被引量:2
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作者 YUECHUN SHI SHUIYING XIANG +10 位作者 XINGXING GUO yahui zhang HONGJI WANG DIANZHUANG ZHENG YUNA zhang YANAN HAN YONG ZHAO XIAOJUN ZHU XIANGFEI CHEN XUN LI YUE HAO 《Photonics Research》 SCIE EI CAS CSCD 2023年第8期1382-1389,共8页
We proposed and experimentally demonstrated a simple and novel photonic spiking neuron based on a distributed feedback(DFB)laser chip with an intracavity saturable absorber(SA).The DFB laser with an intracavity SA(DFB... We proposed and experimentally demonstrated a simple and novel photonic spiking neuron based on a distributed feedback(DFB)laser chip with an intracavity saturable absorber(SA).The DFB laser with an intracavity SA(DFBSA)contains a gain region and an SA region.The gain region is designed and fabricated by the asymmetric equivalentπ-phase shift based on the reconstruction-equivalent-chirp technique.Under properly injected current in the gain region and reversely biased voltage in the SA region,periodic self-pulsation was experimentally observed due to the Q-switching effect.The self-pulsation frequency increases with the increase of the bias current and is within the range of several gigahertz.When the bias current is below the self-pulsation threshold,neuronlike spiking responses appear when external optical stimulus pulses are injected.Experimental results show that the spike threshold,temporal integration,and refractory period can all be observed in the fabricated DFB-SA chip.To numerically verify the experimental findings,a time-dependent coupled-wave equation model was developed,which described the physics processes inside the gain and SA regions.The numerical results agree well with the experimental measurements.We further experimentally demonstrated that the weighted sum output can readily be encoded into the self-pulsation frequency of the DFB-SA neuron.We also benchmarked the handwritten digit classification task with a simple single-layer fully connected neural network.By using the experimentally measured dependence of the self-pulsation frequency on the bias current in the gain region as an activation function,we can achieve a recognition accuracy of 92.2%,which bridges the gap between the continuous valued artificial neural networks and spike-based neuromorphic networks.To the best of our knowledge,this is the first experimental demonstration of a photonic integrated spiking neuron based on a DFB-SA,which shows great potential to realizing large-scale multiwavelength photonic spiking neural network chips. 展开更多
关键词 technique LASER saturable
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Spiking information processing in a single photonic spiking neuron chip with double integrated electronic dendrites 被引量:1
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作者 yahui zhang SHUIYING XIANG +5 位作者 XINGXING GUO YANAN HAN YUECHUN SHI XIANGFEI CHEN GENQUAN HAN YUE HAO 《Photonics Research》 SCIE EI CAS CSCD 2023年第12期2033-2041,共9页
Dendrites,branches of neurons that transmit signals between synapses and soma,play a vital role in spiking information processing,such as nonlinear integration of excitatory and inhibitory stimuli.However,the investig... Dendrites,branches of neurons that transmit signals between synapses and soma,play a vital role in spiking information processing,such as nonlinear integration of excitatory and inhibitory stimuli.However,the investigation of nonlinear integration of dendrites in photonic neurons and the fabrication of photonic neurons including dendritic nonlinear integration in photonic spiking neural networks(SNNs)remain open problems.Here,we fabricate and integrate two dendrites and one soma in a single Fabry–Perot laser with an embedded saturable absorber(FP-SA)neuron to achieve nonlinear integration of excitatory and inhibitory stimuli.Note that the two intrinsic electrodes of the gain section and saturable absorber(SA)section in the FP-SA neuron are defined as two dendrites for two ports of stimuli reception,with one electronic dendrite receiving excitatory stimulus and the other receiving inhibitory stimulus.The stimuli received by two electronic dendrites are integrated non-linearly in a single FP-SA neuron,which generates spikes for photonic SNNs.The properties of frequency encoding and spatiotemporal encoding are investigated experimentally in a single FP-SA neuron with two electronic dendrites.For SNNs equipped with FP-SA neurons,the range of weights between presynaptic neurons and postsynaptic neurons is varied from negative to positive values by biasing the gain and SA sections of FP-SA neurons.Compared with SNN with all-positive weights realized by only biasing the gain section of photonic neurons,the recognition accuracy of Iris flower data is improved numerically in SNN consisting of FP-SA neurons.The results show great potential for multi-functional integrated photonic SNN chips. 展开更多
关键词 ELECTRONIC ABSORBER WEIGHTS
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Carbon dots with two-photon fluorescence imaging for efficient synergistic trimodal therapy
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作者 yahui zhang Haoyu Xia +6 位作者 Mengdie Yang Hairong Li Feishi Shan Yilong Chen Xue Yue Zhouyu Wang Xiaoqi Yu 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第9期171-175,共5页
Applying the fluorescent carbon dots as smart materials in anticancer therapy is of great interest.However,carbon dots for multimodal synergistic anticancer therapy,especially for the triple modality,is rarely reporte... Applying the fluorescent carbon dots as smart materials in anticancer therapy is of great interest.However,carbon dots for multimodal synergistic anticancer therapy,especially for the triple modality,is rarely reported.Herein,we successfully synthesized OCDs by citric acid and(1R,2S)-2-amino-1,2-diphenylethan-1-ol,which show aggregation-induced emission property and two-photon fluorescence imaging.Meanwhile,OCDs are ideal photosensitizers for photothermal therapy under 808 nm and TypeⅠphotodynamic therapy with white light.Hydroxyl radicals,generated by TypeⅠphotodynamic therapy based on OCDs can transform protumoral M2 macrophages into antitumoral M1 macrophages,which exhibited immunotherapy ability.The synergism trimodal of OCDs results in potent anticancer efficacy,showing great potential in cancer therapy. 展开更多
关键词 Carbon dots(CDs) Two-photon imaging Photothermal therapy(PTT) Type I photodynamic therapy(PDT) Synergistic trimodal anticancer therapy
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Red/NIR emission carbonized polymer dots based on citric acid-benzoylurea and their application in lymph nodes imaging
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作者 Feishi Shan Tingrui zhang +10 位作者 Chengshuang Liao Xue Yue Jing zhang Li Yan Yanman Liu Zhixing Cao Min Wang yahui zhang Leyong Wang Zhouyu Wang Xiaoqi Yu 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第11期225-230,共6页
Identification of lymph nodes(LNs)is critical for studies of the structure,the role in disease development,and the efficacy of disease treatment.Carbonized polymer dots(CPDs)are expected to be potential LNs-targeted i... Identification of lymph nodes(LNs)is critical for studies of the structure,the role in disease development,and the efficacy of disease treatment.Carbonized polymer dots(CPDs)are expected to be potential LNs-targeted imaging agents due to their excellent properties with special structure,better photoluminescence(PL)and great biocompatibility.Herein,a red/near infrared(NIR)emission CPDs(RCPDs)with one and two-photon bioimaging based on citric acid(CA)and benzoylurea(BU)are prepared.Notably,the RCPDs are capable of targeting LNs for imaging.Lymphocyte homing has been demonstrated to be the cellular mechanism of RCPDs target LNs imaging.This work has developed a new nanomaterial for targeted imaging of LNs,while the biological applications of CPDs have been expanded and deepened. 展开更多
关键词 Carbonized polymer dots Red/NIR emission LNs-targeting Lymphocyte homing
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