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Fabricating a smart clothing system based on strain-sensing yarn and novel stitching technology for health monitoring

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Science China(Technological Sciences) 2024年第2期67卷 587-596页

作者： TANG Jian WU YuTing MA ShiDong ZHANG YuMin XU RuoJie YAN Tao PAN ZhiJuan College of Textile and Clothing engineering Soochow UniversitySuzhou 215123China National engineering laboratory for Modern Silk Suzhou 215123China

Various yarn-shaped flexible strain sensors have recently been ***,research is lacking on additive manufacturing for smart clothing for integrating yarn sensors with commercial ***,a strain-sensing yarn is sewn into a piece of fabric through a novel stitching technique,and the influence of the stitching method and needle pitch on the sensing performance is investigated using finite element analysis(FEA).The sensing performance could be improved when the sensing yarn is self-locked in the fabric at the needle eyes,and the needle pitch was reduced to 0.5 cm,which is attributed to the enhanced stress and strain ***,the composite sensing fabric featured outstanding performance,including a low detection limit(0.1%),rapid response(280 ms),excellent durability(10000 cycles),and high stability(negligible drift and frequency independence).In addition,the remarkable wear resistance,washability,and anti-interference to ambient humidity and perspiration were ***,the optimal stitch trace lengths of sensing yarn for detecting elbow motion,breathing,and heartbeats are ***,a smart clothing system composed of smart clothing,data acquisition unit,and mobile APP was developed to simultaneously detect human movement and physiological *** work provides a reference to produce intelligent garments based on yarn sensors for health monitoring.

关键词： strain-sensing yarn composite sensing fabric smart clothing system stitching technology health monitoring

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

Effects of the inlet particle spatial distribution on the performance of a gas-solid cyclone separator

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Particuology 2024年第2期85卷 133-145页

作者： Yuge Yao Manxia Shang Xiwei Ke Zhong Huang Tuo Zhou Junfu Lyu Key laboratory for Thermal Science and Power engineering of Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing100084China

The present study was aimed at the inlet particle spatial distribution of a gas-solid separator with high solid loading and investigated its effects on cyclone performance and the inner flow *** flow fields of a cyclone with different rectangular particle flow areas on the inlet surface were numerically simulated using a four-way coupling *** simulated results indicate that reducing the inlet particle flow area and lowing the inlet particle position can effectively reduce the scattered particles inside the cyclone separator and enhance the separation *** gathering the particles to the centerline can also weaken the particle *** particles near the roof account for the swirling particle ceiling *** inlet particle spatial distribution affects the pressure drop mainly by affecting the gas tangential velocity in the cylinder ***,compared to the hori-zontal particle distribution on the inlet surface,the vertical particle distribution has greater effects on cyclone performance.

关键词： Gas-solid cyclone Inlet particle spatial distribution Four-way coupling Separation efficiency Scattered particle

Design of a Bio-inspired,Two-winged,Flapping-wing Micro Air Vehicle with High-lift Performance

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Journal of Bionic engineering 2024年第3期21卷 1191-1207页

作者： Kai Hu Huichao Deng Shengjie Xiao Gongyu Yang Yuhong Sun Space Robot laboratory The School of Mechanical EngineeringBeihang UniversityBeijing100191China

In this paper,we present the development of our latest flapping-wing micro air vehicle(FW-MAV),named Explobird,which features two wings with a wingspan of 195 mm and weighs a mere 25.2 g,enabling it to accomplish vertical take-off and hover *** devised a novel gear-based mechanism for the flapping system to achieve high lift capability and reliability and conducted extensive testing and analysis on the wings to optimise power matching and lift *** Explobird can deliver a peak lift-to-weight ratio of 1.472 and an endurance time of 259 s during hover flight powered by a single-cell LiPo *** the inherent instability of the prototype,we discuss the derivatives of its longitudinal system,underscoring the importance of feedback control,position of the centre of gravity,and increased *** demonstrate the effect of damping enhancement on stability,we also designed a passive stable ***,the vehicle is actively stabilised in roll by adjusting the wing root bars and in pitch through high-authority tail control,whereas yaw is passively *** a series of flight tests,we successfully demonstrate that our prototype can perform vertical take-off and hover flight under wireless *** promising results position the Explobird as a robust vehicle with high lift capability,paving the way towards the use of FW-MAVs for carrying load equipment in multiple tasks.

关键词： Flapping wing Biologically inspired robots Mechanical design Flight dynamics Damping enhancement

Tailoring NH4+ storage by regulating oxygen defect in ammonium vanadate

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Green Energy & Environment 2024年第7期9卷 1171-1182页

作者： Yanyan Liu Ziyi Feng Hanmei Jiang Xueying Dong Changgong Meng Yifu Zhang State Key laboratory of Fine Chemicals School of Chemical Engineering Dalian University of Technology College of Environmental and Chemical engineering Dalian University

Defect engineering is an effective strategy for modifying the energy storage materials to improve their electrochemical ***, the impact of oxygen defect and its content on the electrochemical performances in the burgeoning aqueous NH+4storage field remains explored. Therefore, for the first time in this work, an oxygen-defective ammonium vanadate [（NH4）2V10O25·8H2O, denoted as Od-NHVO] with a novel 3D porous flower-like architecture was achieved via the reduction of thiourea in a mild reaction condition, which is a facile method that can realize the intention to regulate the oxygen defect content, with the capability of mass-production. The as-prepared OdM-NHVO with moderate oxygen defect content can deliver a stable specific capacitance output(505 F g-1, 252 mAh g-1at 0.5 A g-1with ～80% capacitance retention after 10,000 cycles), which benefits from extra active sites, unimpeded NH+4-migration path and relatively high structure integrity. In contrast, low oxygen defect content will lead to the torpid electrochemical reaction kinetics while too high content of it will reduce the chargestorage capability and induce structural disintegration. The superior NH+4-storage behavior is achieved with the reversible intercalation/deintercalation process of NH+4accompanied by forming/breaking of hydrogen bond. As expected, the assembled flexible OdM-NHVO//PTCDI quasi-solid-state hybrid supercapacitor（FQSS HSC） also exhibits high areal capacitance, energy density and reliable flexibility. This work provides a new avenue for developing materials with oxygen-deficient structure for application in various aqueous non-metal cation storage systems.

关键词： Ammonium vanadate Oxygen defect Ammonium-ion storage Hybrid supercapacitors Electrochemical performance

Nickel-catalyzed arylcyanation of alkenes via cyano group translocation:access to 1,n-dinitriles or 4-amino nitriles

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Science China Chemistry 2024年第9期67卷 2975-2981页

作者： Xiaohong Li Shenfan Wang Xiangxiang Fu Donghui Xing Zeyuan Fu Yuanfu Deng Huanfeng Jiang Liangbin Huang State Key laboratory of Pulp and Paper engineering School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China

Herein,a nickel-catalyzed arylcyanation of unactivated alkenes via cyano group translocation with aryl boronic acids has been *** transformations provided a robust approach to constructing structurally diverse 1,n-dinitriles or 4-amino nitriles from easily prepared and commercially available starting *** cyano group translocation was achieved,involving the addition into the intramolecular C–N triple bond followed by the retro-Thorpe *** studies revealed that high temperature and CsHCO_(3) as the base were crucial for the cyano group translocation.

关键词： arylcyanation nickel catalysis cyano group translocation 1 n-dinitriles 4-amino nitriles

Amorphous hybrid tungsten oxide–nickel hydroxide nanosheets used as a highly efficient electrocatalyst for hydrogen evolution reaction

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Nano Research 2024年第4期17卷 2499-2508页

作者： Chao Lyu Chenghai Dai Yiwei Tan State Key laboratory of Materials-Oriented Chemical engineering School of Chemistry and Chemical EngineeringNanjing Tech UniversityNanjing 211816China

There are more challenges for alkaline hydrogen evolution reaction(HER)via simultaneously expediting the electron-coupled water dissociation process(Volmer step)and the following electrochemical H_(2) desorption(Heyrovsky step).Hybrid amorphous electrocatalysts are highly desirable for efficient hydrogen evolution from water-alkali electrolyzers due to the bifunctionality for the different elementary steps of HER and optimal interactions with water molecules and the reactive hydrogen intermediates(Had).Herein,the synthesis of amorphous hybrid ultrathin(tungsten oxide/nickel hydroxide)hydrate(a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O)nanosheets on nickel foam(NF)for efficient alkaline HER is *** structural and composition features of a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O are characterized in *** resulting a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O/NF electrocatalyst with the synergistic effect of both hybrid components for the HER elementary steps shows greatly improved the activity and durability for the HER with a low overpotential of-41 and-163 mV at-10 and-500 mA·cm^(-2),respectively,a Tafel slope as low as-72.9 mV·dec^(-1),and long-term stability of continuous electrolysis for at least 150 h accompanying by inappreciable overpotential change in 1 M *** the hybrid a-[WO_(3)/Ni(OH)_(2)]·0.2H_(2)O,Ni(OH)_(2) and WO_(3) moieties are separately responsible for accelerating dissociative adsorption of water and weakening Had adsorption strength,which is beneficial to the improvement of the alkaline HER activity.

关键词： amorphous nanomaterial bimetallic electrocatalyst tungsten oxide ultrathin nanosheet hydrogen evolution reaction

Characterization of cerebrovascular changes in Alzheimer's disease mice by photoacoustic imaging

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Journal of Innovative Optical Health Sciences 2024年第6期17卷 29-40页

作者： Xi Li Zhongyang Zhang Hua Shi Feifan Zhou Key laboratory of Biomedical engineering of Hainan Province School of Biomedical engineering Hainan University Sanya 572025P.R.China

The cerebral vasculature plays a significant role in the development of Alzheimer's disease(AD),however,the specific association between them remains *** this paper,based on the benefits of photoacoustic imaging(PAI),including label-free,high-resolution,in vivo imaging of vessels,we investigated the structural changes of cerebral vascular in wild-type(WT)mice and AD mice at different ages,analyzed the characteristics of the vascular in different brain regions,and correlated vascular characteristics with cognitive *** results showed that vascular density and vascular branching index in the cortical and frontal regions of both WT and AD mice decreased with ***,vascular lacunarity increased with age,and the changes in vascular structure were more pronounced in AD *** trend of vascular dysfunction aligns with the worsening cognitive dysfunction as the disease ***,we utilized in vivo PAI to analyze the changes in vascular structure during the progression of AD,elucidating the spatial and temporal correlation with cognitive impairment,which will provide more intuitive data for the study of the correlation between cerebrovascular and the development of AD.

关键词： Photoacoustic imaging Alzheimer's disease cerebrovascular vascular network cognitive impairment.

Numerical Study on the Aerodynamic and Fluid−Structure Interaction of An NREL-5MW Wind Turbine

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China Ocean engineering 2024年第3期38卷 363-378页

作者： ZHAO Mi YU Wan-li WANG Pi-guang QU Yang DU Xiu-li Key laboratory of Urban Security and Disaster engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China State Key laboratory of Bridge engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China

A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic *** this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model.

关键词： computational fluid dynamics methods(CFD) tower shadow effect aerodynamic performance fluidstructure interaction space flow field