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Science China(Information Sciences) 2024年第2期67卷 279-290页

作者： xingxing guo Shuiying XIANG Xingyu CAO Biling GU State Key Laboratory of Integrated Service Networks Xidian University State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology School of MicroelectronicsXidian University

In this paper, we propose and demonstrate experimentally and numerically a hierarchical timedelay optical reservoir computing(RC) system based on cascaded vertical-cavity surface-emitting lasers(VCSELs) with feedback and multiple injections. The prediction performance characteristics of the hierarchical time-delay RC system based on cascaded VCSELs under different reservoir layers are ***, the prediction performance of the hierarchical time-delay RC system is first improved and saturates as the number of reservoir layers increases. Besides, the impacts of key factors on predicting the hierarchical time-delay RC system are also analyzed in detail experimentally and numerically. This proposed hierarchical time-delay RC system based on VCSELs is useful for the further development of RC systems and may be beneficial to improve the ability of RC systems to solve more complex problems.

关键词： vertical-cavity surface-emitting laser reservoir computing neuromorphic photonics time-delay system information processing

Conversion of a single-layer ANN to photonic SNN for pattern recognition

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Science China(Information Sciences) 2024年第1期67卷 261-270页

作者： Yanan HAN Shuiying XIANG Tianrui ZHANG Yahui ZHANG xingxing guo Yuechun SHI State Key Laboratory of Integrated Service Networks State Key Discipline Laboratory of Wide Bandgap Semiconductor TechnologyXidian University Yongjiang Laboratory

This work presents a complete conversion scheme for photonic spiking neural networks(SNNs).We verified that the output of an artificial neural network(ANN) trained with the simulated optical activation function can be directly converted into the spike rate of a photonic spiking neuron *** reveal the feasibility of hardware implementation,we considered the effects of different bit precisions of data and weight,noise level,and bias current mismatch on the converted *** proposed scheme was evaluated using the Deterding vowel,IRIS,TIDIGITS,and MNIST datasets for pattern recognition,and achieved mean accuracies of 95.80%,98.67%,96.19%,and 92.33%,*** proposed scheme can convert an ANN into a photonic SNN with almost no precision loss,and the performance was comparable to that of an ANN trained with the rectified linear unit *** proposed scheme can enable the high-performance implementation of photonic SNNs.

关键词： photonic SNN conversion optical computing pattern recognition artificial neural network

Short-term prediction for chaotic time series based on photonic reservoir computing using VCSEL with a feedback loop

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Photonics Research 2024年第6期12卷 1222-1230页

作者： xingxing guo HANXU ZHOU SHUIYING XIANG QIAN YU YAHUI ZHANG YANAN HAN TAO WANG YUE HAO State Key Laboratory of Integrated Service Networks Xidian UniversityXi'an 710071China State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology School of MicroelectronicsXidian UniversityXi'an 710071China

Chaos,occurring in a deterministic system,has permeated various fields such as mathematics,physics,and life ***,the prediction of chaotic time series has received widespread attention and made signifi-cant ***,many problems,such as high computational complexity and difficulty in hardware im-plementation,could not be solved by existing *** 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 ***,a photonic reservoir com-puting based on VCSEL,along with a feedback loop,is proposed for the short-term prediction of the chaotic time *** 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 ***,the attention coefficient of injection strength and feedback strength,prediction duration,and other factors on system perfor-mance are considered in both simulation and *** 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.

关键词： loop chaotic prediction

Experimental demonstration of a photonic spiking neuron based on a DFB laser subject to side-mode optical pulse injection

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Science China(Information Sciences) 2024年第3期67卷 271-280页

作者： Shuiying XIANG Shuang GAO Yuechun SHI Yuna ZHANG Ziwei SONG xingxing guo Yahui ZHANG Yuxin MA Xiangfei CHEN State Key Laboratory of Integrated Service Networks Xidian University Yongjiang Laboratory 3. College of Engineering and Applied Sciences Nanjing University

We proposed and experimentally demonstrated a simple and novel photonic spiking neuron based on a distributed feedback(DFB) laser subject to side-mode optical pulse injection(SMOPI). The DFB laser chip is designed and fabricated based on asymmetric equivalent π phase shift(π-EPS) with the reconstruction-equivalent-chirp(REC) technique. Under side-mode continuous-wave(CW) optical injection,excitability pulse was experimentally observed during the dominant mode switching process due to the injection-locked effect. Based on the transition between the excitability regime and the side-mode injection locking effect, the controllable and repeatable neuron-like spiking response can be realized when external stimulus pulses are electro-optically modulated on the CW optical carrier. The experimental results show that the spike threshold, temporal integration, and refractory period, which are important spike processing mechanisms in biological neurons, can all be achieved in the optically-injected DFB laser. The experimental findings are also verified numerically with a rate equation model that considers the SMOPI. To the best of our knowledge, this is the first experimental demonstration of a photonic spiking neuron based on a DFB laser subject to SMOPI, which holds promise for realizing large-scale photonic spiking neuron arrays for hardware photonic spiking neural network chips.

关键词： neuromorphic photonics photonic spiking neuron DFB laser side-mode optical pulse injections

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艾司氯胺酮诱导睡眠对呼吸和气道梗阻的影响

中外医学研究 2024年第9期22卷 114-118页

作者：郭星星广东省人民医院珠海医院(珠海市金湾中心医院) 广东珠海519000

目的:探讨艾司氯胺酮诱导睡眠对患者呼吸和气道梗阻的影响。方法:选择2021年1—6月于广东省人民医院珠海医院拟行药物诱导睡眠检查的患者60例,采用随机数法随机分为Ⅰ组、Ⅱ组,各30例。Ⅰ组使用艾司氯胺酮进行诱导睡眠,Ⅱ组使用咪达唑... 详细信息

目的:探讨艾司氯胺酮诱导睡眠对患者呼吸和气道梗阻的影响。方法:选择2021年1—6月于广东省人民医院珠海医院拟行药物诱导睡眠检查的患者60例,采用随机数法随机分为Ⅰ组、Ⅱ组,各30例。Ⅰ组使用艾司氯胺酮进行诱导睡眠,Ⅱ组使用咪达唑仑进行诱导睡眠,患者入睡后,在仰卧位下,使用纤维喉镜监测患者气道梗阻情况,记录用药前(T0)、用药后5 min(T1)、用药后10 min(T2)、用药后20 min(T3)、用药后30 min(T4)时的Ramsay镇静评分、呼吸频率(RR)、最低血氧饱和度(SpO2),睡眠呼吸监测指标、气道梗阻情况及不良反应等。结果:T1~T4时,两组Ramsay镇静评分比较,差异无统计学意义(P>0.05)。T1~T4时,两组SpO2均低于T0时,差异有统计学意义(P0.05)。结论:艾司氯胺酮诱导睡眠对呼吸抑制较轻,气道梗阻发生率较低。

关键词：艾司氯胺酮药物诱导睡眠呼吸抑制气道梗阻

云南普阳煤矿新近系褐煤中稀土元素的赋存状态

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地质学报 2024年第8期98卷 2452-2471页

作者：汪小妹郭星星韩宇轩徐振宇杨浩然李宝庆中国地质大学(武汉)构造与油气资源教育部重点实验室湖北武汉430074

目前对于褐煤中稀土元素(REY)赋存状态的研究还存在较多疑问,主要体现在两个方面:一是褐煤中REY究竟主要赋存于有机质中还是矿物质中?二是褐煤含有较多容易受到酸溶干扰的含氧官能团,在逐级化学提取实验过程中,高比例HCl提取相中的REY... 详细信息

目前对于褐煤中稀土元素(REY)赋存状态的研究还存在较多疑问,主要体现在两个方面:一是褐煤中REY究竟主要赋存于有机质中还是矿物质中?二是褐煤含有较多容易受到酸溶干扰的含氧官能团,在逐级化学提取实验过程中,高比例HCl提取相中的REY究竟来自于碳酸盐、磷酸盐、单硫化物等矿物还是来自于有机质?着眼于此,本文在逐级化学提取这一常规元素赋存状态研究方法的基础上,结合密度分离实验、红外光谱(FTIR)等手段,对普阳煤矿新近系褐煤中REY的赋存状态进行了系统研究。研究结果表明,普阳煤矿M2和M3煤层为极低—中灰、中高—高挥发分、中硫分褐煤,其组成矿物主要为石英、方解石、高岭石、黄铁矿。M2和M3煤层中常量元素以Al和Si为主,其REY配分模式主要为L型和N型,其中M2煤层中REY轻度富集。逐级化学提取实验结果显示M2和M3煤层中的REY主要被HCl浸取,其次被HNO3浸取,同时还有部分REY保留在残渣中,HF对煤中REY的提取率很低(一般<10%)。密度分离实验结果表明REY主要赋存于低密度组分中。红外光谱分析结果显示煤样品经HCl处理后,酚羟基、羟基等含氧官能团增多,可能是经HCl浸取后样品中与酚羟基、羟基点位结合的REY被浸出迁移所致。综合来看,普阳煤矿M2和M3煤层中的REY主要赋存于有机质中,少量赋存于硅酸盐矿物中,碳酸盐、磷酸盐、单硫化物和双硫化物也可能是部分REY的赋存载体。逐级化学提取实验过程中HCl所提取的异常高比例的REY可能主要来自于有机质。

关键词：普阳煤矿褐煤稀土元素逐级化学提取红外光谱

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Spiking information processing in a single photonic spiking neuron chip with double integrated electronic dendrites

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Photonics Research 2023年第12期11卷 2033-2041页

作者： YAHUI ZHANG SHUIYING XIANG xingxing guo YANAN HAN YUECHUN SHI XIANGFEI CHEN GENQUAN HAN YUE HAO State Key Laboratory of Integrated Service Networks Xidian UniversityXi’an 710071China State Key Discipline Laboratory of Wide Bandgap Semiconductor Technology Xidian UniversityXi’an 710071China Yongjiang Laboratory Ningbo 315202China Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of EducationNational Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesInstitute of Optical Communication EngineeringNanjing UniversityNanjing 210023China

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 ***,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 ***,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 *** 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 *** stimuli received by two electronic dendrites are integrated non-linearly in a single FP-SA neuron,which generates spikes for photonic *** properties of frequency encoding and spatiotemporal encoding are investigated experimentally in a single FP-SA neuron with two electronic *** 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 *** 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 *** results show great potential for multi-functional integrated photonic SNN chips.

关键词： electronic absorber weights

Nonlinear neural computation in an integrated FP-SA spiking neuron subject to incoherent dual-wavelength optical pulse injections

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Science China(Information Sciences) 2023年第12期66卷 299-300页

作者： Ziwei SONG Shuiying XIANG xingxing guo Shuang GAO Biling GU Dianzhuang ZHENG Xiangfei CHEN Yuechun SHI State Key Laboratory of Integrated Service Networks State Key Discipline Laboratory of Wide Bandgap Semiconductor TechnologyXidian University 2. Yongjiang Laboratory Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of EducationNational Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesInstitute of Optical Communication EngineeringNanjing University

Photonic nonlinear computation is the critical cornerstone of photonic neuromorphic computing. As one of the key information function units in the photonic spiking neural networks, the photonic spiking neurons are responsible for the nonlinear computation of the network. Recently, the neuron-like nonlinear computation of the photonic spiking neuron has attracted considerable attention.

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Experimental demonstration of coherent photonic neural computing based on a Fabry–Perot laser with a saturable absorber

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Photonics Research 2023年第1期11卷 65-71页

作者： DIANZHUANG ZHENG SHUIYING XIANG xingxing guo YAHUI ZHANG BILING GU HONGJI WANG ZHENZHEN XU XIAOJUN ZHU YUECHUN SHI YUE HAO State Key Laboratory of Integrated Service Networks Xidian UniversityXi'an 710071China State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology School of MicroelectronicsXidian UniversityXi'an 710071China Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of EducationNational Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesInstitute of Optical Communication EngineeringNanjing UniversityNanjing 210023China School of Information Science and Technology Nantong UniversityNantong 226019China Yongjiang Laboratory Ningbo 315202China

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 *** neural computing has become a promising approach to overcome the von Neuman ***,while photonic neural networks are good at linear computing,it is difficult to achieve nonlinear ***,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 *** linear computation and nonlinear computation are realized in the *** such a coherent architecture,two presynaptic signals are modulated and weighted with two intensity modulation MZMs through the same optical *** nonlinear neuron-like dynamics including temporal integration,threshold,and refractory period are successfully ***,the effects of frequency detuning on the nonlinear neuron-like dynamics are also explored,and the frequency detuning condition is *** proposed hardware architecture plays a foundational role in constructing a large-scale coherent photonic spiking neural network.

关键词： tuning laser neural

Impacts of permafrost degradation on streamflow in the northern Himalayas

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Science China Earth Sciences 2024年第6期67卷 1990-2000页

作者： Linfeng FAN Fang JI xingxing KUANG Zhilin guo Rui ZHANG Chunmiao ZHENG State Key Laboratory of Mountain Hazards and Engineering Resilience Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610299China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210024China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Eastern Institute for Advanced Study Ningbo 315200China

The Himalayan water tower provides crucial water resources for *** degradation is deemed to exert important impacts on streamflow in the Himalayan ***,the magnitudes of such impacts remain poorly ***,we established a robust hydrological model that incorporated active layer deepening and ground ice melt for the drainage basin of the largest river in the northern Himalayas-the Yarlung Zangbo River(YZR).We estimated that permafrost degradation led to~0.65 km^(3)/yr decrease in surface runoff and~0.35 km^(3)/yr increase in baseflow and ground ice melt contributed~0.25% to the annual streamflow in the YZR for the period ***“fill-and-spill”mechanism helps explain the seeming contradiction of observed increasing versus decreasing baseflow in different permafrost regions *** propose that the dilution of riverine dissolved organic carbon(DOC)concentrations by baseflow may lead to the riverine DOC hysteresis *** study not only lays solid scientific basis for water resources management in the Himalayas,but also yields new insights into how to interpret measured river discharge and nutrient flux in permafrost regions over the globe.

关键词： Permafrost degradation Hydrology Streamflow Surface runoff Groundwater Himalayas

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