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Hidden Two-Stream Collaborative learning Network for Action Recognition

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Computers, Materials & Continua 2020年第6期63卷 1545-1561页

作者： Shuren Zhou le Chen Vijayan Sugumaran School of Computer and Communication Engineering Changsha University of Science and TechnologyChangsha410114China Department of Decision and Information Sciences School of Business AdministrationOakland UniversityRochester48309USA

The two-stream convolutional neural network exhibits excellent performance in the video action recognition.The crux of the matter is to use the frames already clipped by the videos and the optical flow images pre-extracted by the frames,to train a model each,and to finally integrate the outputs of the two models.Nevertheless,the reliance on the pre-extraction of the optical flow impedes the efficiency of action recognition,and the temporal and the spatial streams are just simply fused at the ends,with one stream failing and the other stream succeeding.We propose a novel hidden two-stream collaborative(HTSC)learning network that masks the steps of extracting the optical flow in the network and greatly speeds up the action recognition.Based on the two-stream method,the two-stream collaborative learning model captures the interaction of the temporal and spatial features to greatly enhance the accuracy of recognition.Our proposed method is highly capable of achieving the balance of efficiency and precision on large-scale video action recognition datasets.

关键词： Action recognition collaborative learning optical flow

The role of fibronectin in multiple sclerosis and the effect of drug delivery across the blood-brain barrier

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Neural Regeneration Research 2023年第10期18卷 2147-2155页

作者： Shuang-Shuang Wei le Chen Feng-Yuan Yang Si-Qi Wang Peng Wang Ningxia Key Laboratory of Craniocerebral Diseases School of Clinical MedicineNingxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina Ningxia Key Laboratory of Craniocerebral Diseases Ningxia Medical UniversityYinchuanNingxia Hui Autonomous RegionChina

Remyelination failure is one of the main characteristics of multiple sclerosis and is potentially correlated with disease progression.Previous research has shown that the extracellular matrix is associated with remyelination failure because remodeling of the matrix often fails in both chronic and progressive multiple sclerosis.Fibronectin aggregates are assembled and persistently exist in chronic multiple sclerosis,thus inhibiting remyelination.Although many advances have been made in the mechanisms and treatment of multiple sclerosis,it remains very difficult for drugs to reach pathological brain tissues;this is due to the complexity of brain structure and function,especially the existence of the blood-brain barrier.Therefore,herein,we review the effects of fibronectin aggregates on multiple sclerosis and the efficacy of different forms of drug delivery across the blood-brain barrier in the treatment of this disease.

关键词： blood-brain barrier brain delivery exosomes extracellular matrix fibronectin aggregates fibronectin intestinal flora multiple sclerosis remyelination failure remyelination

Molecular understanding of cation effects on double layers and their significance to CO-CO dimerization

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National Science Review 2023年第9期10卷 125-135页

作者： Jia-Bo le Ao chen Yongbo Kuang Jun cheng Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of Zhejiang Province Ningbo Institute of Materials Technology and EngineeringChinese Academy of Sciences State Key Laboratory of Physical Chemistry of Solid Surfaces iChEM College of Chemistry and Chemical EngineeringXiamen University Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)

Cation effects have been shown in numerous experiments to play a significant role in electro catalysis.To understand these effects at the molecular level,we systematically investigate the structures and capacitances of electric double layers with a variety of cations as counter charges at Pt(111)-COad/water interfaces with ab initio molecular dynamics.It is encouraging to find that the computed Helmholtz capacitances for different cations are in quantitative agreement with experiments,and that the trend of cation effects on capacitances shows clear correlation with the structures of interface cations of differing sizes and hydration energies.More importantly,we demonstrate the Helmholtz capacitance as the key descriptor for measuring the activity of CO-CO dimerization,the rate-determining step for C2+formation in electroreduction of CO and CO2.Our work provides atomistic insights into cation effects on electric double layers and electrocatalysis that are crucial for optimizing electrode and electrolyte materials.

关键词： cation effect electrocatalysis electric double layer CO-CO dimerization ab initio molecular dynamics

Necklace-like carbon nanofibers encapsulating MoO_(2) nanospheres with Mo-C bonding for stable lithium-ion storage

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稀有金属:英文版 2023年第8期42卷 2592-2600页

作者： Jing chen Xuan-le Chen Rou Lu Yong Li An-Qiang Pan School of Physics and Materials Nanchang UniversityNanchang 330031China State Key Laboratory of Powder Metallurgy School of Materials Science and EngineeringCentral South UniversityChangsha 410083China

Molybdenum dioxide has aroused a wide concern as anode material for lithium-ion batteries(LIBs)due to its high theoretical capacity and high density.However,it still faces the problems of large volume changes and low electronic conductivities,which limits its practical application.Herein,necklace-like N-doped carbon nanofibers encapsulating MoO_(2)nanospheres(MoO_(2)@NCNFs)with Mo-C bonding have been designed to address these issues.The rational design carbon coating structure can not only enhance the electron transfer,but also markedly strengthen structural stability.As expected,the as-prepared electrode showed superior lithium storage capacity,including a high specific capacity of 1120 mAh·g^(-1)at 0.1 A·g^(-1),and good rate performance of 502 mAh·g^(-1)at 4.0 A·g^(-1)and a prolonged cycling stability of 490 mAh·g^(-1)capacity retention over 3000 cycles at 4.0 A·g^(-1).

关键词： lithium bonding cycling

Design,synthesis and applications of functional zirconium-based metal-organic frameworks

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Science China Chemistry 2023年第12期66卷 3383-3397页

作者： le Shi Zhenning Yang Fanrui Sha Zhijie chen Stoddart Institute of Molecular Science Department of ChemistryZhejiang UniversityHangzhou 310058China Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials ZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou 311215China Department of Chemistry and International Institute for Nanotechnology Northwestern UniversityEvanstonIllinois 60208United States

Zirconium-based metal-organic frameworks(Zr-MOFs)have been explored for applications including but not limited to water adsorption,gas storage and separation,heterogeneous catalysis,and chemical sensing.Zr-MOFs serve as a major class of functional MOFs thanks to their high thermal,chemical and hydrolytic stability,large surface area,and tunable structures with the versatile connectivity.In this work,we highlight the design and synthesis of zirconium-based MOFs as well as their applications.Specifically,we demonstrate how reticular chemistry can direct the rational design and synthesis of functional ZrMOFs and describe their structure–property relationship.In addition,we feature synthetic strategies,including isoreticular expansion,linker functionalization,node functionalization,and defect engineering,as toolkits to construct tailored material for specific applications.

关键词： metal-organic frameworks Zr-MOFs reticular chemistry structure–property relationship

Improved lazy theta algorithm based on octree map for path planning of UAV

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Defence Technology（防务技术） 2023年第5期23卷 8-18页

作者： Meng-shun Yuan Tong-le Zhou Mou chen College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing211106China

This paper investigates the path planning method of unmanned aerial vehicle(UAV)in threedimensional map.Firstly,in order to keep a safe distance between UAV and obstacles,the obstacle grid in the map is expanded.By using the data structure of octree,the octree map is constructed,and the search nodes is significantly reduced.Then,the lazy theta*algorithm,including neighbor node search,line-of-sight algorithm and heuristics weight adjustment is improved.In the process of node search,UAV constraint conditions are considered to ensure the planned path is actually flyable.The redundant nodes are reduced by the line-of-sight algorithm through judging whether visible between two nodes.Heuristic weight adjustment strategy is employed to control the precision and speed of search.Finally,the simulation results show that the improved lazy theta*algorithm is suitable for path planning of UAV in complex environment with multi-constraints.The effectiveness and flight ability of the algorithm are verified by comparing experiments and real flight.

关键词： Unmanned aerial vehicle Path planning Lazy theta*algorithm Octree map Line-of-sight algorithm

Recent advances of metal phosphides for Li-S chemistry

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Journal of Energy Chemistry 2021年第4期30卷 533-548页

作者： Songlin Yu Wenlong Cai le Chen Lixian Song Yingze Song State Key Laboratory of Environment-Friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang 621010SichuanChina Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity(1672 m Ah g^(-1))and high energy density(2600 Wh kg^(-1)).However,critical issues,mainly pertaining to lithium polysulfide shuttle and slow sulfur reaction kinetics,have posed a fatal threat to the electrochemical performances of Li-S batteries.The situation is even worse for high sulfur-loaded and flexible cathodes,which are the essential components for practical Li-S batteries.In response,the use of metal compounds as electrocatalysts in Li-S systems have been confirmed as an effective strategy to date.Particularly,recent years have witnessed many progresses in phosphidesoptimized Li-S chemistry.This has been motivated by the superior electron conductivity and high electrocatalytic activity of phosphides.In this tutorial review,we offer a systematic summary of active metal phosphides as promoters for Li-S chemistry,aiming at helping to understanding the working mechanism of phosphide electrocatalysts and guiding the construction of advanced Li-S batteries.

关键词： Metal phosphides Li-S chemistry Polysulfide regulation Electrocatalysis

Rock mass quality prediction on tunnel faces with incomplete multi-source dataset via tree-augmented naive Bayesian network

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International Journal of Mining Science and Technology 2024年第3期34卷 323-337页

作者： Hongwei Huang chen Wu Mingliang Zhou Jiayao chen Tianze Han le Zhang Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China Qingdao Guoxin Second Jiaozhou Bay Subsea Tunnel Co. Ltd.Qingdao 266071China

Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel faces.In tunneling practice,the rock mass quality is often assessed via a combination of qualitative and quantitative parameters.However,due to the harsh on-site construction conditions,it is rather difficult to obtain some of the evaluation parameters which are essential for the rock mass quality prediction.In this study,a novel improved Swin Transformer is proposed to detect,segment,and quantify rock mass characteristic parameters such as water leakage,fractures,weak interlayers.The site experiment results demonstrate that the improved Swin Transformer achieves optimal segmentation results and achieving accuracies of 92%,81%,and 86%for water leakage,fractures,and weak interlayers,respectively.A multisource rock tunnel face characteristic(RTFC)dataset includes 11 parameters for predicting rock mass quality is established.Considering the limitations in predictive performance of incomplete evaluation parameters exist in this dataset,a novel tree-augmented naive Bayesian network(BN)is proposed to address the challenge of the incomplete dataset and achieved a prediction accuracy of 88%.In comparison with other commonly used Machine learning models the proposed BN-based approach proved an improved performance on predicting the rock mass quality with the incomplete dataset.By utilizing the established BN,a further sensitivity analysis is conducted to quantitatively evaluate the importance of the various parameters,results indicate that the rock strength and fractures parameter exert the most significant influence on rock mass quality.

关键词： Rock mass quality Tunnel faces Incomplete multi-source dataset Improved Swin Transformer Bayesian networks

Hexagonally ordered microbowl arrays decorated with ultrathin CuInS_(2) nanosheets for enhanced photoelectrochemical performance

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Journal of Energy Chemistry 2020年第12期29卷 134-142页

作者： Ming Li le Chen Yanjie Su Huan Yin Kexiang Hu State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China School of Electronic Engineering and Automation Guilin University of Electronic TechnologyKey Laboratory of Optoelectronic Information Processing of Guangxi Colleges and Uniy/ersitiesGuilin 541004GuangxiChina Key Laboratory for Thin Film and Microfabrication of the Ministry of Education Department of Micro/Nano ElectronicsSchool of ElectronicsInformation and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China National and Local Joint Engineering Laboratory of Internet Technology on Mine School of Information and Control EngineeringChina University of Mining and TechnologyXuzhou 221008JiangsuChina School of Physics and Telecommunication Engineering Guangxi Colleges and Universities Key Lab of Complex System Optimization and Big Data ProcessingYulin Normal UniversityYulin 537400GuangxiChina

This paper demonstrates the design and fabrication of three-dimensional(3 D) hexagonally ordered microbowl arrays(MBAs) decorated with Cu In S2 nanosheets for enhanced photoelectrochemical(PEC) performance. The 3 D MBAs are fabricated by a micro-fabrication technique. The ultrathin CuInS2 nanosheets are grown on the 3 D electrodes by solvothermal transformation of Cu film. The photocurrent density of 3 D photocathode(CuInS2@MBAs) is about two times higher than that of the planar counterpart(CuInS2@Planar). The improved PEC performance can be ascribed to the elevated light trapping ability and the increased surface area for loading photocatalysts. In addition, CdS quantum dots as cocatalysts are modified onto the Cu In S2 nanosheets to further enhance the PEC activity because the formed p-n heterojunction can accelerate the separation of photogenerated carriers. As a result, the 3 D photocathode of CuInS2/CdS@MBAs shows an optimal incident photon to current efficiency of 10% at the wavelength of400 nm. It is believed that this work can be generalized to design other hierarchical 3 D photoelectrodes for improved solar water splitting.

关键词： Microbowl array CuInS_(2) Nanosheet Photocathode Photoelectrochemical performance