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DRAM:A DRL-based resource allocation scheme for MAR in MEC

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Digital Communications and Networks 2023年第3期9卷 723-733页

作者： Tongyu Song Xuebin Tan Jing Ren wenyu Hu Sheng wang Shizhong Xu Xiong wang Gang Sun Hongfang Yu School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengduPR China

Mobile Edge Computing(MEC)and 5G technology allow clients to access computing resources at the network frontier,which paves the way for applying Mobile Augmented Reality(MAR)applications.Under the MEC paradigm,MAR clients can offload complex tasks to the MEC server and enhance the human perception of the world by merging the received virtual information with the real environment.However,the resource allocation problem arises as a critical challenge in circumstances where several MAR clients compete for limited resources at the network frontier.In this paper,we aim to design an online resource allocation scheme on the MEC server that takes both high quality of experience and good fairness performance for MAR clients into consideration.We first formulate this problem as a Markov decision process and tackle the challenge of applying the deep reinforcement learning paradigm.Then,we propose DRAM,a Deep reinforcement learning-based Resource allocation scheme for mobile Augmented reality service in MEC.We also propose a self-adaptive algorithm on the MAR client that is derived based on the analysis of the MAR service to tackle client adaptation problems.The simulation results demonstrated that DRAM can provide high quality of experience and simultaneously achieve good fairness performance by coordinating with clients’adaptation algorithms.

关键词： Mobile edge computing Mobile augmented reality Deep reinforcement learning Resource allocation

Low thermal conductivity of dense(TiZrHfVNbTa)C_(x) high-entropy carbides by tailoring carbon stoichiometry

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Journal of Advanced Ceramics 2023年第1期12卷 49-58页

作者： Lei CHEN Wen ZHANG wenyu LU Boxin WEI Sijia HUO Yujin wang Yu ZHOU Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structural–Functional Integration Materials&Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150001China

Transition metal carbides are promising candidates for thermal protection materials due to their high melting points and excellent mechanical properties.However,the relatively high thermal conductivity is still a major obstacle to its application in an ultra-high-temperature insulation system.In this work,the low thermal conductivity of dense(TiZrHfVNbTa)Cx(x=0.6-1)high-entropy carbides has been realized by adjusting the carbon stoichiometry.The thermal conductivity gradually decreases from 10.6 W·m^(−1)·K^(−1) at room temperature to 6.4 W·m^(−1)·K^(−1) with carbon vacancies increasing.Due to enhanced scattering of phonons and electrons by the carbon vacancies,nearly full-dense(97.9%)(TiZrHfVNbTa)C_(0.6) possesses low thermal conductivity of 6.4 W·m^(−1)·K^(−1),thermal diffusivity of 2.3 mm^(2)·s^(−1),as well as electrical resistivity of 165.5μΩ·cm.The thermal conductivity of(TiZrHfVNbTa)C_(0.6) is lower than that of other quaternary and quinary high-entropy carbide ceramics,even if taking the difference of porosity into account in some cases,which is mainly attributed to compositional complexity and carbon vacancies.This provides a promising route to reduce the thermal conductivity of high-entropy carbides by increasing the number of metallic elements and carbon vacancies.

关键词： high-entropy carbides thermal conductivity compositional complexity carbon vacancies

In situ formation of ionically conductive nanointerphase on Si particles for stable battery anode

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Science China Chemistry 2021年第8期64卷 1417-1425页

作者： Xiaoxue Chen Gaofeng Ge Wenyu Wang Bao Zhang Jianjun Jiang Xuelin Yang Yuzhang Li Li wang Xiangming He Yongming Sun Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan430074China College of Electrical Engineering&New Energy Hubei Provincial Collaborative Innovation Center for New Energy MicrogridChina Three Gorges UniversityYichang443002China College of Materials and Chemical Engineering University of CaliforniaLos Angeles90095USA Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing100084China

Silicon(Si)is a promising anode candidate for next-generation lithium-ion batteries(LIBs)due to its high theoretical capacity.Solar Si photovoltaic waste possesses good purity and high output.Using it as the raw material for battery anodes can synchronously solve the problem of solid waste pollution and enable high energy density LIBs.A critical issue impeding the practical application of Si is the undesirable side reactions at the electrolyte-particle interface and the resulting increase in impedance during cycling.Herein,a Si-P core shell structure with chemical bonding at the Si-P interface is fabricated through a simple mechanical alloying reaction between red P and solar Si photovoltaic waste.The P nanoshell with thickness within 15 nm converts to Li3P during the initial lithiation process and maintains its phase on cycling.The as-formed Li3P nanolayer functions as a stable,ionically conductive protective layer that reduces the direct contact between Si and electrolytes,and thus suppresses undesired side reactions.The Si-P nanocomposite exhibits stable electrochemical cycling with a high reversible capacity of 1,178 mAh g^(−1)after 500 cycles at 1,200 mA g^(−1),as well as excellent rate capability(912 mAh g^(−1)at 2 C).With 15 wt%addition to graphite,a graphite/Si-P hybrid electrode shows a high overall reversible specific capacity of 447 mAh g^(−1)and 88.3%capacity retention after 100 cycles at high areal capacity of 2.64 mAh cm^(−2) at 100 mA g^(−1),indicating its promise as a drop-in anode in practical LIBs.

关键词： silicon anode Li3P interface stability lithium-ion batteries

3D-printed tissue repair patch combining mechanical support and magnetism for controlled skeletal muscle regeneration

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Bio-Design and Manufacturing 2022年第2期5卷 249-264页

作者： Xiaocheng wang Ruibo Zhao Jian wang Xinghuan Li Lijuan Jin wenyu Liu Lifang Yang Yonghua Zhu Zhikai Tan College of Biology Hunan UniversityChangsha 410082China Department of Orthopaedics Xiangya HospitalCentral South UniversityChangsha 410008China Key Laboratory of Carcinogenesis and Cancer Invasions of Ministry of Education School of Basic Medicine ScienceCancer Research InstituteCentral South UniversityChangsha 410008China

Physical forces,such as magnetic and mechanical stimulation,are known to play a significant role in the regulation of cell response.In the present study,a biomimetic regeneration patch was fabricated using E-jet 3 D printing,which integrates mechanical and magnetic stimulation in a biocompatible"one-pot reaction"strategy when combined with a static magnetic field(SMF).The magneto-based therapeutic regeneration patch induced myoblasts to form aligned and multinucleated myotubes,regulated the expression of myogenic-related genes,and activated the p38αmitogen-activated protein kinase pathway via the initiation of myogenic differentiation.To validate the efficiency of the proposed strategy,the regeneration patch was implanted into mice and exposed to a suitable SMF,which resulted in significantly enhanced in vivo skeletal muscle regeneration.The findings demonstrated that appropriate external physical stimulation provides a suitable biophysical microenvironment that is conducive to tissue regeneration.The method used in the present study represents a promising technique to induce the regeneration of damaged skeletal muscle tis sue.

关键词： Functional biomaterials Magnetic actuation Myogenic differentiation Skeletal muscle regeneration 3D printing

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司法人工智能:实现裁判正义的新路径

大连理工大学学报（社会科学版） 2022年第6期43卷 100-109页

作者：王文玉重庆大学法学院重庆400044

与传统法官裁判相比,司法人工智能在实现裁判正义方面有以下优势:能够弥补法官理性的有限性;保障同案同判的实现;推动司法公开的完善;显著提升司法效率。司法人工智能为裁判正义的实现带来变革性的同时,也面临着一系列的技术难题、价值... 详细信息

与传统法官裁判相比,司法人工智能在实现裁判正义方面有以下优势:能够弥补法官理性的有限性;保障同案同判的实现;推动司法公开的完善;显著提升司法效率。司法人工智能为裁判正义的实现带来变革性的同时,也面临着一系列的技术难题、价值挑战以及法治困境。在明确了司法人工智能只是法官的“帮工”而不是“替身”的定位基础上,可以通过案件繁简分流的方式发挥司法人工智能在提升裁判效率和准确性上的优势。同时由办案法官承担主要责任的责任承担机制也更具可行性和合理性。提升算法的可解释性、建立算法审查以及案例筛选和退出机制是破解司法人工智能算法难题的关键,而复合型人才的培养则是实现我国司法人工智能长久、优质发展的基础和前提。

关键词：司法人工智能裁判正义技术难题价值挑战法治风险

Satellite Navigation Method Based on High-Speed Frequency Hopping Signal

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China Communications 2023年第7期20卷 321-337页

作者： En Yuan Peng Liu Weiwei Chen Rui wang Bing Xu wenyu Zhang Yanqin Tang Command&Control Engineering College Army Engineering University of PLANanjing 210007China

Global navigation satellite system has been widely used,but it is vulnerable to jamming.In military satellite communications,frequency hopping(FH)signal is usually used for anti-jamming communications.If the FH signal can be used in satellite navigation,the anti-jamming ability of satellite navigation can be improved.Although a recently proposed timefrequency matrix ranging method(TFMR)can use FH signals to realize pseudorange measurement,it cannot transmit navigation messages using the ranging signal which is crucial for satellite navigation.In this article,we propose dual-tone binary frequency shift keyingbased TFMR(DBFSK-TFMR).DBFSK-TFMR designs an extended time-frequency matrix(ETFM)and its generation algorithm,which can use the frequency differences in different dual-tone signals in ETFM to modulate data and eliminate the negative impact of data modulation on pseudorange measurement.Using ETFM,DBFSK-TFMR not only realizes the navigation message transmission but also ensures the precision and unambiguous measurement range of pseudorange measurement.DBFSK-TFMR can be used as an integrated solution for anti-jamming communication and navigation based on FH signals.Simulation results show that DBFSK-TFMR has almost the same ranging performance as TFMR.

关键词： satellite navigation frequency hopping ranging navigation message transmission

Using a skillful statistical model to predict September sea ice covering Arctic shipping routes

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Acta Oceanologica Sinica 2020年第5期39卷 11-25页

作者： Sha Li Muyin wang wenyu Huang Shiming Xu Bin wang Yuqi Bai Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084China Joint Institute for the Study of the Atmosphere and Ocean University of WashingtonSeattle WA98195USA Pacific Marine Environmental Laboratory National Oceanic and Atmospheric AdministrationSeattle WA98115USA State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The rapid decrease in Arctic sea ice cover and thickness not only has a linkage with extreme weather in the midlatitudes but also brings more opportunities for Arctic shipping routes and polar resource exploration,both of which motivate us to further understand causes of sea-ice variations and to obtain more accurate estimates of seaice cover in the future.Here,a novel data-driven method,the causal effect networks algorithm,is applied to identify the direct precursors of September sea-ice extent covering the Northern Sea Route and Transpolar Sea Route at different lead times so that statistical models can be constructed for sea-ice prediction.The whole study area was also divided into two parts:the northern region covered by multiyear ice and the southern region covered by seasonal ice.The forecast models of September sea-ice extent in the whole study area(TSIE)and southern region(SSIE)at lead times of 1–4 months can explain over 65%and 79%of the variances,respectively,but the forecast skill of sea-ice extent in the northern region(NSIE)is limited at a lead time of 1 month.At lead times of 1–4 months,local sea-ice concentration and sea-ice thickness have a larger influence on September TSIE and SSIE than other teleconnection factors.When the lead time is more than 4 months,the surface meridional wind anomaly from northern Europe in the preceding autumn or early winter is dominant for September TSIE variations but is comparable to thermodynamic factors for NSIE and SSIE.We suggest that this study provides a complementary approach for predicting regional sea ice and is helpful in evaluating and improving climate models.

关键词： regional sea ice Arctic shipping routes machine learning statistical model predictions

A hierarchical heterostructure of CdS QDs confined on 3D ZnIn_(2)S_(4) with boosted charge transfer for photocatalytic CO_(2) reduction

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Nano Research 2021年第1期14卷 81-90页

作者： Zezhou Zhu Xiaoxia Li Yunteng Qu Fangyao Zhou Zhiyuan wang Wenyu Wang Changming Zhao Huijuan wang Liqiang Li Yagang Yao Qun Zhang Yuen Wu School of Nano-Tech and Nano-Bionics Hefei National Laboratory for Physical Sciences at the MicroscaleCollaborative Innovation Center of Chemistry for Energy Materials(iChEM)School of Chemistry and Materials Scienceand National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale Synergetic Innovation Center of Quantum Information and Quantum PhysicsDepartment of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China Division of Advanced Nanomaterials Suzhou Institute of Nano-tech and Nano-bionicsChinese Academy of SciencesSuzhou 215123China Center for Micro and Nanoscale Research and Fabrication University of Science and Technology of ChinaHefei 230026China

Metal sulfide based materials as photocatalysts for energy conversion are essential to produce value-added chemical fuels,but their intrinsically slow carrier dynamics and low activity are yet to be resolved.Herein,we developed a unique heterogeneously nanostructured ZnIn_(2)S_(4)-CdS heterostructure that involves zero-dimensional(0D)CdS quantum dots uniformly confined on three-dimensional(3D)ZnIn_(2)S_(4)nanoflowers,which achieves an excellent catalytic performance of CO_(2) photoconversion under visible-light irradiation.The obtained hierarchical heterostructure can significantly enhance the light harvesting,shorten the migration distance of carriers,and obviously accelerate the transport of electrons.As evidenced by the ultrafast transient absorption spectroscopy,the formed interface can effectively facilitate charge separation and transport.This work opens up a new avenue to carefully design the elaborate heterostructures for achieving optimal charge separation efficiency by lowering interfacial kinetic barriers and energy losses at the interface.

关键词： photocatalysis CO_(2)reduction charge transfer hierarchical heterostructure

Can sub-GeV dark matter coherently scatter on the electrons in the atom?

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Communications in Theoretical Physics 2023年第1期75卷 74-85页

作者： Ji-Heng Guo Yu-Xuan Sun Wenyu Wang Ke-Yun Wu Faculty of Science Beijing University of TechnologyBeijingChina

A novel detection of sub-GeV dark matter is proposed in the paper.The electron cloud is boosted by the dark matter and emits an electron when it is dragged back by the heavy nucleus,namely the coherent scattering of the electron cloud of the atom.The survey in the x-ray diffraction shows that the atomic form factors are much more complex than the naive consideration.The results of the relativistic Hartree-Fock(RHF)method give non-trivial shapes of the atoms.The detailed calculation of the recoil of the electron cloud,the kinetics,the fiducial cross section and the corresponding calculation of detection rate are given analytically.The numerical results show that the limits of the RHF form factors are much more stringent than the recoil of a single electron,almost 4 orders stronger,and also give tight limitations compared to the Migdal effect below about several hundred MeV.The physical picture and the corresponding results are promising and need further exploration.

关键词： dark matter coherent scattering form factor