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Highly efficient fiber to Si waveguide free-form coupler for foundry-scale silicon photonics

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Photonics research 2024年第5期12卷 1055-1066页

作者： LUIGI RANNO JIA Xu BRIAN SIA COSMIN POPESCU DREW WENINGER SAMUEL SERNA SHAOLIANG YU LIONEL C.KIMERLING ANURADHA AGARWAL TIAN GU JUEJUN HU Department of Materials Science&Engineering Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA centre for Micro-&Nano-electronics(CMNE) Nanyang Technological UniversitySingapore 639798Singapore Department of Physics Photonics and Optical EngineeringBridgewater State UniversityBridgewaterMassachusetts 02324USA Zhejiang Laboratory Hangzhou 311100China Materials research Laboratory Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA

As silicon photonics transitions from research to commercial deployment,packaging solutions that efficiently couple light into highly compact and functional sub-micrometer silicon waveguides are imperative but remain *** 220 nm silicon-on-insulator(SOI)platform,poised to enable large-scale integration,is the most widely adopted by foundries,resulting in established fabrication processes and extensive photonic component *** development of a highly efficient,scalable,and broadband coupling scheme for this platform is therefore of paramount *** two-photon polymerization(TPP)and a deterministic free-form micro-optics design methodology based on the Fermat’s principle,this work demonstrates an ultraefficient and broadband 3-D coupler interface between standard SMF-28 single-mode fibers and silicon waveguides on the 220 nm SOI *** coupler achieves a low coupling loss of 0.8 dB for the fundamental TE mode,along with 1 dB bandwidth exceeding 180 *** broadband operation enables diverse bandwidthdriven applications ranging from communications to ***,the 3-D free-form coupler also enables large tolerance to fiber misalignments and manufacturing variability,thereby relaxing packaging requirements toward cost reduction capitalizing on standard electronic packaging process flows.

关键词： fiber waveguide enable

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Dynamics of an impurity ion transport in oil-paper insulation under various electric fields

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High Voltage 2024年第1期9卷 66-80页

作者： Yuanyang Ren Yang Wang Qiankai Zhang Jiayu Xiong Wen Cao Zepeng Lv Kai Wu State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina School of electronics and Information Xi'an Polytechnic UniversityXi'anChina State Grid Sichuan Electric Power research Institute ChengduChina

The ionic transport process is an important counterpart to charge transport in oil-paper insulation,and it significantly impacts oil flow electrification at the oil-paper *** this,the dynamics of this phenomenon and the underlying mechanisms remain unclear,particularly at the molecular *** understand this fundamental aspect,we conduct Molecular Dynamics study on the transport behaviour of an impurity ion in different oil-paper insulation models under various external electric *** influence factors,such as external electric fields,temperatures,and local structural characteristics,are investigated in relation to the corresponding ionic mobility in different polymer *** to the simulations,ionic mobility and its response to electric fields are higher in weaker electrostatic *** a result,mineral oil exhibits the highest ionic mobility and the most substantial enhancement of ionic mobility by external electric fields,followed by vegetable oil,oil-paper blends,and insulating *** significant deviation in ionic mobility between oil and paper leads to the formation of an electric double layer near the oil-paper *** underlying physical mechanisms of different ionic mobility and its response to the electric field in different polymer models could be explained by the different polymer structural influences in terms of interaction energy and coordination numbers in a static manner,as well as by the interactions between the impurity ion and its surrounding atoms in terms of lifetime correlation functions and velocity autocorrelation functions in a dynamic *** addition,the influence of temperature on ionic mobility in mineral and vegetable oil is examined,and their activation energies are *** in the fundamental understanding of the dynamics of the ion transport process in oil-paper insulation is vital to improving their insulating properties for oil-impregnated power transformers.

关键词： insulation transport fields

Real-time UAV path planning based on LSTM network

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Journal of Systems Engineering and electronics 2024年第2期35卷 374-385页

作者： ZHANG Jiandong GUO Yukun ZHENG Lihui YANG Qiming SHI Guoqing WU Yong School of electronics and Information Northwestern Polytechnical UniversityXi’an 710129China The Flight Automatic Control research Institute of AVIC Xi’an 710065China Military Representative Office of Marine Wuhan Bureau in Luoyang Area Luoyang 471000China

To address the shortcomings of single-step decision making in the existing deep reinforcement learning based unmanned aerial vehicle(UAV)real-time path planning problem,a real-time UAV path planning algorithm based on long shortterm memory(RPP-LSTM)network is proposed,which combines the memory characteristics of recurrent neural network(RNN)and the deep reinforcement learning *** networks are used in this algorithm as Q-value networks for the deep Q network(DQN)algorithm,which makes the decision of the Q-value network has some *** to LSTM network,the Q-value network can use the previous environmental information and action information which effectively avoids the problem of single-step decision considering only the current ***,the algorithm proposes a hierarchical reward and punishment function for the specific problem of UAV real-time path planning,so that the UAV can more reasonably perform path *** verification shows that compared with the traditional feed-forward neural network(FNN)based UAV autonomous path planning algorithm,the RPP-LSTM proposed in this paper can adapt to more complex environments and has significantly improved robustness and accuracy when performing UAV real-time path planning.

关键词： deep Q network path planning neural network unmanned aerial vehicle(UAV) long short-term memory(LSTM)

Applying heteroatom co-doped carbon nanotube for manifesting high performance in the electrochemical reduction of aqueous nitrogen oxide by gold nanoparticles

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Nano research 2024年第3期17卷 1151-1164页

作者： Jane Chung Haibo Yin Rong Wang Yunlong Wang Junyang Zhang Yue Peng Joung Woo Han Seongyun Ryu Junhua Li State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China EHS research Center Samsung Electronics Co.Ltd.Gyeonggi-do 18448Republic of Korea

Electrochemical NO-to-NH_(3) under ambient conditions could be a viable alternative having advantages in terms of energy consumption and exhaust gas recycling of NO,replacing a traditional ammonia synthesis method of the Haber–Bosch *** synthesizing boron(B-)and nitrogen(N-)co-doped carbon nanotube(CNT)based gold(Au)catalysts,B-dopants elevate the conductivity of carbon nanotube by sp2 hybridization on graphene and implant B–N domains within the graphene layer,and result in facilitating the embedding amount of Au accompanied by high dispersibility with low particle *** density functional theory(DFT)calculations elucidate that the electron cloud transmitted from B-dopant to the active site of Au induces the Lewis acidic site,and the O-distal pathway occurs following a spontaneous *** of the electron-deficient B-doping area accompanied by N-defects and B–O edges retains the major valence state of Au as Au^(δ+),and suppresses hydrogen evolution reaction(HER)by repulsing the hindrance of H*.This record exhibits the highest faradaic efficiency(FE)of 94.7%,and NH_(3) yield rate of 1877.4μg·h^(-1)·mg_(cat)^(-1),which is the optimal yield over energy consumption in the field of the ambient reduction of aqueous NO.

关键词： boron heteroatom nitrogen defect gold nanoparticles valence states of gold electrochemical NO-to-NH3

Single-atom catalysts supported on graphene/electride heterostructures for the enhanced sulfur reduction reaction in lithium-sulfur batteries

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Journal of Energy Chemistry 2024年第10期97卷 738-746页

作者： Siyun Qi Chuanchuan Li Gang Chen Mingwen Zhao School of Physics and electronics Shandong Normal University Qingdao Industrial Energy Storage research Institute Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences School of Physics & State Key Laboratory of Crystal Materials Shandong University

Single-atom catalysts（SACs） hold great promise in addressing the sluggish kinetics of the sulfur reduction reaction（SRR） in lithium-sulfur（Li-S） batteries for their unique catalytic activity and maximum atom *** these SACs must be dispersed on solid substrates,the underlying support is usually limited to carbon materials that have a poor ability to modulate the coordination environment and electronic structures of single atoms,and consequently their catalytic activity toward the SRR is *** we propose two-dimensional（2D） graphene/electride heterostructu res as substrates to enhance the catalytic activities of SACs for Li-S batteries.2D electrides featuring the anionic electron gas on their surface enable efficient electron transfer to SACs,which alters their electronic structures,resulting in the shifts of the d orbital and Fermi *** unique electronic structure decreases the filling of antibonding states such that the bonding with adsorbates at active sites is *** demonstrate the enhanced catalytic performance of SACs in terms of the Gibbs free energy of SRR and Li2S *** addition,a universal descriptor for the rapid screening of SACs is established by a linear regression fitting *** work provides a new design strategy to modulate SAC activity through electrides for Li-S batteries.

关键词： Charge transfers DFT calculations Electrides Kinetics Universal descriptors

Loyal wingman task execution for future aerial combat:A hierarchical prior-based reinforcement learning approach

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Chinese Journal of Aeronautics 2024年第5期37卷 462-481页

作者： Jiandong ZHANG Dinghan WANG Qiming YANG Zhuoyong SHI Longmeng JI Guoqing SHI Yong WU School of electronics and Information Northwestern Polytechnical UniversityXi’an 710129China

In modern Beyond-Visual-Range(BVR)aerial combat,unmanned loyal wingmen are pivotal,yet their autonomous capabilities are *** study introduces an advanced control algorithm based on hierarchical reinforcement learning to enhance these capabilities for critical missions like target search,positioning,and relay *** on a dual-layer model,the algorithm’s lower layer manages basic aircraft maneuvers for optimal flight,while the upper layer processes battlefield dynamics,issuing precise navigational *** approach enables accurate navigation and effective reconnaissance for lead ***,our Hierarchical Prior-augmented Proximal Policy Optimization(HPE-PPO)algorithm employs a prior-based training,prior-free execution method,accelerating target positioning training and ensuring robust target *** paper also improves missile relay guidance and promotes the effective *** integrating this system with a human-piloted lead aircraft,this paper proposes a potent solution for cooperative aerial *** experiments demonstrate enhanced survivability and efficiency of loyal wingmen,marking a significant contribution to Unmanned Aerial Vehicles(UAV)formation control *** advancement is poised to drive substantial interest and progress in the related technological fields.

关键词： Beyond-visual-range Loyal wingmen Hierarchical prior-augmented proximal policy optimization Unmanned aerial vehicles Warfare

A drug-loaded flexible substrate improves the performance of conformal cortical electrodes

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Bio-Design and Manufacturing 2024年第4期7卷 399-412页

作者： Rongrong Qin Tian Li Yifu Tan Fanqi Sun Yuhao Zhou Ronghao Lv Xiaoli You Bowen Ji Peng Li Wei Huang Frontiers Science Center for Flexible electronics(FSCFE) Xi’an Institute of Flexible Electronics(IFE)and Xi’an Institute of Biomedical Materials&Engineering(IBME)Northwestern Polytechnical UniversityXi’an 710072China Unmanned System research Institute Northwestern Polytechnical UniversityXi’an 710072China Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Flexible electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China

Cortical electrodes are a powerful tool for the stimulation and/or recording of electrical activity in the nervous ***,the inevitable wound caused by surgical implantation of electrodes presents bacterial infection and inflammatory reaction risks associated with foreign body ***,inflammation of the wound area can dramatically worsen in response to bacterial *** consequences can not only lead to the failure of cortical electrode implantation but also threaten the lives of ***,we prepared a hydrogel made of bacterial cellulose(BC),a flexible substrate for cortical electrodes,and further loaded antibiotic tetracycline(TC)and the anti-inflammatory drug dexamethasone(DEX)onto *** encapsulated drugs can be released from the BC hydrogel and effectively inhibit the growth of Gram-negative and Gram-positive ***,therapeutic cortical electrodes were developed by integrating the drug-loaded BC hydrogel and nine-channel serpentine arrays;these were used to record electrocorticography(ECoG)signals in a rat *** to the controlled release of TC and DEX from the BC hydrogel substrate,therapeutic cortical electrodes can alleviate or prevent symptoms associated with the bacterial infection and inflammation of brain *** approach facilitates the development of drug delivery electrodes for resolving complications caused by implantable electrodes.

关键词： Antibacterial Anti-inflammatory Drug loading Cortical electrodes Bacterial cellulose hydrogel

Perception Enhanced Deep Deterministic Policy Gradient for Autonomous Driving in Complex Scenarios

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 557-576页

作者： Lyuchao Liao Hankun Xiao Pengqi Xing Zhenhua Gan Youpeng He Jiajun Wang Fujian Provincial Key Laboratory of Automotive electronics and Electric Drive Fujian University of TechnologyFuzhou350118China Fujian Provincial Universities Engineering research Center for Intelligent Driving Technology Fuzhou350118China

Autonomous driving has witnessed rapid advancement;however,ensuring safe and efficient driving in intricate scenarios remains a critical *** particular,traffic roundabouts bring a set of challenges to autonomous driving due to the unpredictable entry and exit of vehicles,susceptibility to traffic flow bottlenecks,and imperfect data in perceiving environmental information,rendering them a vital issue in the practical application of autonomous *** address the traffic challenges,this work focused on complex roundabouts with multi-lane and proposed a Perception EnhancedDeepDeterministic Policy Gradient(PE-DDPG)for AutonomousDriving in the ***,themodel incorporates an enhanced variational autoencoder featuring an integrated spatial attention mechanism alongside the Deep Deterministic Policy Gradient framework,enhancing the vehicle’s capability to comprehend complex roundabout environments and make ***,the PE-DDPG model combines a dynamic path optimization strategy for roundabout scenarios,effectively mitigating traffic bottlenecks and augmenting throughput *** experiments were conducted with the collaborative simulation platform of CARLA and SUMO,and the experimental results show that the proposed PE-DDPG outperforms the baseline methods in terms of the convergence capacity of the training process,the smoothness of driving and the traffic efficiency with diverse traffic flow patterns and penetration rates of autonomous vehicles(AVs).Generally,the proposed PE-DDPGmodel could be employed for autonomous driving in complex scenarios with imperfect data.

关键词： Autonomous driving traffic roundabouts deep deterministic policy gradient spatial attention mechanisms

The Effect of Uncaria gambir on Optical Properties and Thermal Stability of CNF/PVA Biocomposite Films

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Journal of Renewable Materials 2024年第9期12卷 1593-1603页

作者： Remon Lapisa Anna Niska Fauza Dieter Rahmadiawan Dori Yuvenda Randi Purnama Putra Nandy Putra Hairul Abral Mechanical Engineering Department Universitas Negeri PadangPadang25173Indonesia centre for Energy and Power electronics research Universitas Negeri PadangPadang25173Indonesia Department of Mechanical Engineering National Cheng Kung University(NCKU)Tainan70101Taiwan Mechanical Engineering Department Universitas IndonesiaDepok16424Indonesia Mechanical Engineering Department Universitas AndalasPadang25163Indonesia

Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding properties. Among all types of cellulose materials available, cellulose nanofiber (CNF) has great potential to be utilized in a diverse range of applications, including as a film material. In this study, CNF biocomposite film was prepared by using polyvinyl alcohol (PVA) as a matrix and Uncaria gambir extract as a filler. This study aims to investigate the effect of Uncaria gambir extract on the optical properties and thermal stability of the produced film. The formation of the CNF biocomposite films was confirmed using Fourier Transform Infrared Spectroscopy, their transmittance characteristics were measured using UV-Vis spectroscopy and a transmittance meter, while their reflectance was determined using a reflectance meter. The results revealed that the addition of Uncaria gambir extract to the CNF biocomposite film improved its UV-shielding properties, as indicated by the lower percentage of transmittance in the visible region, 10%–70%. In addition, its reflectance increased to 10.6% compared to the CNF film without the addition of Uncaria gambir extract. Furthermore, the thermal stability of the CNF biocomposite film with the addition of Uncaria gambir extract improved to around 400°C–500°C. In conclusion, the results showed that CNF biocomposite film prepared by adding Uncaria gambir extract can be a promising candidate for optical and thermal management materials.

关键词： Cellulose nanofiber biocomposite film optical properties Uncaria gambir thermal stability