In this paper,we propose and experimentally demonstrate a joint shaping technique to improve the performance of a lowresolution transmission system for the first time,to the best of our knowledge.The joint shaping tec...In this paper,we propose and experimentally demonstrate a joint shaping technique to improve the performance of a lowresolution transmission system for the first time,to the best of our knowledge.The joint shaping technique combines probabilistic shaping(PS)and error feedback noise shaping(EFNS).In the 40-Gbaud intensity-modulation direct-detection(IM/DD)experimental transmission system,a bit-error-rate(BER)of 3.8×10^(-3)can be achieved easily with the joint shaping at the physical number of bits(PNOB)of 3.In the 30-Gbaud dual polarization(DP)coherent experimental transmission system,a BER below 1×10^(-3)is easily obtained with a 3-bit quantizer by using joint shaping.The optimization of the shaping degree is also analyzed.展开更多
Realization of functional flexible artificial synapse is a significant step toward neuromorphic computing.Herein,a flexible artificial synapse based on ferroelectric tunnel junctions(FTJs)is demonstrated,using BiFeO_(...Realization of functional flexible artificial synapse is a significant step toward neuromorphic computing.Herein,a flexible artificial synapse based on ferroelectric tunnel junctions(FTJs)is demonstrated,using BiFeO_(3)(BFO)thin film as the functional layer.The inorganic single crystalline FTJs grown on rigid perovskite substrates at high temperatures are integrated with the flexible plastic substrates,by using the water-soluble Sr_(3)Al_(2)O_(6)(SAO)as the sacrificial layer and the following transfer.The transferred freestanding BFO thin film exhibits excellent ferroelectric properties.Moreover,the memristive properties and the brain-like synaptic learning performance of the flexible FTJs are investigated.The results show that multilevel resistance states were maintained well of the flexible artificial synapse,together with their stable synaptic learning properties.Our work indicates the promising opportunity of ferroelectric thin film based flexible synapse used in the future neuromorphic computing system.展开更多
The analog photonics link(APL) is widely used in microwave photonics. However, in wideband and multi-carrier systems, the third inter-modulation distortion(IMD3) and cross-modulation distortion(XMD) will jointly limit...The analog photonics link(APL) is widely used in microwave photonics. However, in wideband and multi-carrier systems, the third inter-modulation distortion(IMD3) and cross-modulation distortion(XMD) will jointly limit the spurious-free dynamic range(SFDR) of links. In this paper, we experimentally present a linearized wideband and multi-carrier APL, in which the IMD3 and XMD are mitigated simultaneously by using artificial neural networks with transfer learning(TL-ANN). In this experiment, with different artificial neural networks, which are trained with the knowledge obtained from the two-or three-sub-carrier system, the IMD3 and XMD are suppressed by 21.71 d B and 11.11 d B or 22.38 d B and 16.73 d B, and the SFDR is improved by 13.4 d B or 14.3 d B, respectively. Meanwhile, compared with previous studies, this method could reduce the training time and training epochs to 16% and 25%.展开更多
The roof arrester of electric multiple units(EMU)can efficiently limit the overvoltage,and ensure the safe operation of the EMU electrical equipment.In the process of high‐speed operation,the traction power supply sy...The roof arrester of electric multiple units(EMU)can efficiently limit the overvoltage,and ensure the safe operation of the EMU electrical equipment.In the process of high‐speed operation,the traction power supply system is often affected by overvoltage.In addition,roof arrester explosion accidents occasionally occur.In this paper,the on‐line voltage measurement system of the EMU arrester is developed.By analysing a large number of voltage waveforms,the abnormal voltage is divided into three categories:over‐phase voltage,high harmonic voltage and steep impulse overvoltage.The charac-teristics of abnormal voltage waveforms are then summarised.The electrothermal coupling simulation model of the arrester is developed,and the current response and temperature distribution of the arrester under abnormal voltage are calculated.The impact of the impulse voltage energy on the arrester temperature is studied by applying a triangular wave voltage to the model.Finally,some suggestions are proposed for the operation and maintenance of the roof arrester.展开更多
基金supported by the National Key R&D Plan“Nano Frontier”Key Special Project(2021YFA1200502)the National Natural Science Foundation of China(62004056,61874158,and 62104058)+12 种基金the Cultivation Projects of National Major R&D Project(92164109)the Special Project of Strategic Leading Science and Technology of Chinese Academy of Sciences(XDB44000000-7)Hebei Basic Research Special Key Project(F2021201045)the Support Program for the Top Young Talents of Hebei Province(70280011807)the Supporting Plan for 100 Excellent Innovative Talents in Colleges and Universities of Hebei Province(SLRC2019018)the Interdisciplinary Research Program of Natural Science of Hebei University(DXK202101)the Institute of Life Sciences and Green Development(521100311)the Natural Science Foundation of Hebei Province(F2022201054 and F2021201022)the Outstanding Young Scientific Research and Innovation Team of Hebei University(605020521001)the Special Support Funds for National High Level Talents(041500120001)the Advanced Talents Incubation Program of the Hebei University(521000981426,521100221071,and 521000981363)the Science and Technology Project of Hebei Education Department(QN2020178 and QN2021026)Baoding Science and Technology Plan Project(2172P011)。
基金financially supported by the National Natural Science Foundation of China(61674050,62004056,and 61874158)the Project of Distinguished Young of Hebei Province(A2018201231)+7 种基金the Support Program for the Top Young Talents of Hebei Province(70280011807)the Hundred Persons Plan of Hebei Province(E2018050004 and E2018050003)the Supporting Plan for 100 Excellent Innovative Talents in Colleges and Universities of Hebei Province(SLRC2019018)the Special Project of Strategic Leading Science and Technology of Chinese Academy of Sciences(XDB44000000-7)the Special Support Funds for National High Level Talents(041500120001)Hebei Basic Research Special Key Project(F2021201045)the Science and Technology Project of Hebei Education Department(QN2020178 and QN2021026)Singapore Ministry of Education(Ac RF TIER 2-MOE2019-T2-2-075)。
基金supported by the National Key R&D Program of China(No.2019YFB1803504)the National Natural Science Foundation of China(Nos.61821001,61901045,and 61625104)the Fund of State Key Laboratory of Information Photonics and Optical Communication BUPT(No.IPOC2021ZT18)。
文摘In this paper,we propose and experimentally demonstrate a joint shaping technique to improve the performance of a lowresolution transmission system for the first time,to the best of our knowledge.The joint shaping technique combines probabilistic shaping(PS)and error feedback noise shaping(EFNS).In the 40-Gbaud intensity-modulation direct-detection(IM/DD)experimental transmission system,a bit-error-rate(BER)of 3.8×10^(-3)can be achieved easily with the joint shaping at the physical number of bits(PNOB)of 3.In the 30-Gbaud dual polarization(DP)coherent experimental transmission system,a BER below 1×10^(-3)is easily obtained with a 3-bit quantizer by using joint shaping.The optimization of the shaping degree is also analyzed.
基金the National Natural Science Foundation of China(No.62004056)the Hundred Persons Plan of Hebei Province(Nos.E2018050004 and E2018050003)+5 种基金This work was also supported by National Natural Science Foundation of China(Nos.61674050 and 61874158)the Outstanding Youth Project of Hebei Province(No.F2016201220)the Project of Distinguished Young of Hebei Province(No.A2018201231)he Support Program for the Top Young Talents of Hebei Province(No.70280011807)the Training and Introduction of High-level Innovative Talents of Hebei University(No.801260201300)the Supporting Plan for 100 Excellent Innovative Talents in Colleges and Universities of Hebei Province(No.SLRC2019018).
文摘Realization of functional flexible artificial synapse is a significant step toward neuromorphic computing.Herein,a flexible artificial synapse based on ferroelectric tunnel junctions(FTJs)is demonstrated,using BiFeO_(3)(BFO)thin film as the functional layer.The inorganic single crystalline FTJs grown on rigid perovskite substrates at high temperatures are integrated with the flexible plastic substrates,by using the water-soluble Sr_(3)Al_(2)O_(6)(SAO)as the sacrificial layer and the following transfer.The transferred freestanding BFO thin film exhibits excellent ferroelectric properties.Moreover,the memristive properties and the brain-like synaptic learning performance of the flexible FTJs are investigated.The results show that multilevel resistance states were maintained well of the flexible artificial synapse,together with their stable synaptic learning properties.Our work indicates the promising opportunity of ferroelectric thin film based flexible synapse used in the future neuromorphic computing system.
基金This work was supported in part by the National Key R&D Program of China(No.2019YFB1803504)National Natural Science Foundation of China(Nos.61901045,61821001,and 61625104)+1 种基金Fundamental Research Funds for the Central Universities(No.2019RC11)State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)(No.IPOC2019ZT04)。
文摘The analog photonics link(APL) is widely used in microwave photonics. However, in wideband and multi-carrier systems, the third inter-modulation distortion(IMD3) and cross-modulation distortion(XMD) will jointly limit the spurious-free dynamic range(SFDR) of links. In this paper, we experimentally present a linearized wideband and multi-carrier APL, in which the IMD3 and XMD are mitigated simultaneously by using artificial neural networks with transfer learning(TL-ANN). In this experiment, with different artificial neural networks, which are trained with the knowledge obtained from the two-or three-sub-carrier system, the IMD3 and XMD are suppressed by 21.71 d B and 11.11 d B or 22.38 d B and 16.73 d B, and the SFDR is improved by 13.4 d B or 14.3 d B, respectively. Meanwhile, compared with previous studies, this method could reduce the training time and training epochs to 16% and 25%.
文摘The roof arrester of electric multiple units(EMU)can efficiently limit the overvoltage,and ensure the safe operation of the EMU electrical equipment.In the process of high‐speed operation,the traction power supply system is often affected by overvoltage.In addition,roof arrester explosion accidents occasionally occur.In this paper,the on‐line voltage measurement system of the EMU arrester is developed.By analysing a large number of voltage waveforms,the abnormal voltage is divided into three categories:over‐phase voltage,high harmonic voltage and steep impulse overvoltage.The charac-teristics of abnormal voltage waveforms are then summarised.The electrothermal coupling simulation model of the arrester is developed,and the current response and temperature distribution of the arrester under abnormal voltage are calculated.The impact of the impulse voltage energy on the arrester temperature is studied by applying a triangular wave voltage to the model.Finally,some suggestions are proposed for the operation and maintenance of the roof arrester.
