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Cooperative channel assignment for VANETs based on multiagent reinforcement learning

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Frontiers of Information Technology & Electronic Engineering 2020年第7期21卷 1047-1058页

作者： yun-peng wang Kun-xian ZHENG Da-xin TIAN Xu-ting DUAN Jian-shan ZHOU Beijing Advanced Innovation Center for Big Data and Brain Computing School of Transportation Science and EngineeringBeihang UniversityBeijing 100191China

Dynamic channel assignment(DCA)plays a key role in extending vehicular ad-hoc network capacity and mitigating ***,channel assignment under vehicular direct communication scenarios faces mutual influence of large-scale nodes,the lack of centralized coordination,unknown global state information,and other *** solve this problem,a multiagent reinforcement learning(RL)based cooperative DCA(RLCDCA)mechanism is ***,each vehicular node can successfully learn the proper strategies of channel selection and backoff adaptation from the real-time channel state information(CSI)using two cooperative RL *** addition,neural networks are constructed as nonlinear Q-function approximators,which facilitates the mapping of the continuously sensed input to the mixed policy *** are driven to locally share and incorporate their individual rewards such that they can optimize their policies in a distributed collaborative *** results show that the proposed multiagent RL-CDCA can better reduce the one-hop packet delay by no less than 73.73%,improve the packet delivery ratio by no less than 12.66%on average in a highly dense situation,and improve the fairness of the global network resource allocation.

关键词： Vehicular ad-hoc networks Reinforcement learning Dynamic channel assignment Multichannel

Laboratory Detection and Diagnosis of Filoviruses

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Virologica Sinica 2011年第2期26卷 73-80页

作者： yun-peng wang Xian-en Zhang Hong-ping Wei State Key Laboratory of Virology Wuhan Institute of Virology Chinese Academy of Sciences Wuhan 430071China

Ebola virus(EBOV) and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other *** high as 50-90% mortality,filoviruses can cause significant threats to public ***,so far no specific and efficient vaccine has been available,nor have other treatment methods proved to be *** is of great importance to detect these pathogens specific,rapidly and sensitively in order to control future filovirus ***,recent progresses in the development of detection and diagnosis methods for EBOV and MARV are summarized.

关键词： Filovirus Ebola virus (EBOV) Marburg virus (MARV) Enzyme-linked immunosorbent assay(ELISA) Polymerase chain reaction (PCR)

Optimized Selection Method of Air Combat Course of Action under Stochastic Uncertainty

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Journal of Systems Science and Systems Engineering 2024年第4期33卷 494-518页

作者： yun Zhong Jieyong Zhang peng Sun Lujun Wan Kepeng wang Information and Navigation College Air Force Engineering UniversityXi’an710077China Equipment Management and Unmanned Aerial Vehicle Engineering College Air Force Engineering UniversityXi’an710051China Air Traffic Control and Navigation College Air Force Engineering UniversityXi’an710051China Unit 94040 of PLA Korla841000China

Aiming at the design problem of aviation swarm combat course of action(COA),considering the influence of stochastic parameters in the causal relationship model and optimization problem model,according to the dynamic influence net(DIN)theory,stochastic simulation technique,feedforward neural network(FNN)function approximation technique and multi-objective artificial fish school algorithm(MOAFSA),this paper proposed a COA optimized method based on DIN and multi-objective stochastic chance constraint optimization for aviation swarm ***,on the basis of establishing the overall framework of the model and defining the elements of causal relationship modeling,the static and dynamic causal relationship modeling and optimization problem modeling were carried out ***,the probability propagation mechanism of DIN was established,which mainly included two aspects,i.e.,the overall process and the specific ***,input and output data were generated based on stochastic *** to these data,FNN was adopted for function approximation,and MOAFSA was adopted for iterative ***,the rationality of the model,and the effectiveness and superiority of the algorithm were verified through multiple sets of simulation cases.

关键词： Stochastic uncertainty aviation swarm stochastic simulation course of action feedforward neural network multi-objective artificial fish school algorithm

Essential oil of Actinidia macrosperma, a catnip response kiwi endemic to China

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第9期7卷 708-712页

作者： ZHAO yun-peng wang Xiao-yun wang Zhi-can LU Yin FU Cheng-xin CHEN Shao-yuan Research Program for Medicinal Plant Resource Lab of Systematic ＆ Evolutionary Botany and Biodiversity School of Life Sciences Zhejiang University Hangzhou 310058. China

Objective: To identify compounds that may be responsible for catnip response of Actinidia macrosperma, and compare chemical compositions in the wild and in vitro regenerated plants. Methods: GC-MS and relative retention indices with n-alkanes as reference points were used for compound identification, and component relative percentage was calculated based on GC peak areas without using correction factors. Results: There are 28 compounds (92.72%) and 15 compounds (93.88%) identi- fied in the essential oils from the wild and regenerated plants, respectively. Dihydronepetalactone, iridomyrmecin, and dihydro- actinidiolide, which are believed to be attractive to felines, are present in both wild and regenerated plants. Actinine was not detected, and beta-pheylethyl alcohol was only present in wild plant. In addition, short-chain enol derivatives, messengers in chemical communication, are commonly present in wild plant of A. macrosperma, but absent in regenerated one. Conclusion: Dihydronepetalactone, iridomyrmecin, and dihydroactinidiolide are responsible for the catnip response of A. macrosperma.

关键词： Actinidia macrosperma GC-MS Dihydronepetalactone lridomyrmecin Dihydroactinidiolide Catnip response

Current development of body-centered cubic high-entropy alloys for nuclear applications

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Tungsten 2021年第2期3卷 197-217页

作者： Tan Shi peng-Hui Lei Xu Yan Jing Li yun-Di Zhou yun-peng wang Zheng-Xiong Su Yan-Kun Dou Xin-Fu He Di yun Wen Yang Chen-Yang Lu Department of Nuclear Science and Technology Xi’an Jiaotong UniversityXi’an 710049China China Institute of Atomic Energy Beijing 102413China

High-entropy alloys greatly expand the alloy design range and offer new possibilities for improving material *** on the worldwide research efforts in the last decade,the excellent mechanical properties and promising radiation and corrosion resistance of this group of materials have been ***-entropy alloys with body-centered cubic(BCC)structures,especially refractory high-entropy alloys,are considered as promising materials for high-temperature applications in advanced nuclear ***,the extreme reactor conditions including high temperature,high radiation damage,high stress,and complex corrosive environment require a comprehensive evaluation of the material properties for their actual service in nuclear *** review summarizes the current progress on BCC high-entropy alloys from the aspects of neutron economy and activation,mechanical properties,high-temperature stability,radiation resistance,as well as corrosion *** the current development of BCC high-entropy alloys for nuclear applications is still at an early stage as the large design space of this group of alloys has not been fully explored,the current research findings provide a good basis for the understanding and prediction of material behaviors with different compositions and *** in-depth understanding of the degradation mechanisms and characterization of material properties in response to conditions close to reactor environment are necessary.A critical down-selection of potential candidates is also crucial for further comprehensive evaluation and engineering validation.

关键词： Body-centered cubic high-entropy alloys Refractory high-entropy alloys Nuclear materials Radiation damage Tungsten

Tailoring chaotic motion of microcavity photons in ray and wave dynamics by tuning the curvature of space

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 107-112页

作者： Wei Lin Yechun Ding Yongsheng wang peng Li Yanpeng Zhang Feng yun Feng Li Key Laboratory for Physical Electronics and Devices of the Ministry of Education Shaanxi Key Lab of Information Photonic TechniqueSchool of Electronic Science and EngineeringFaculty of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049China Department of Electrical and Photonics Engineering Technical University of DenmarkKgs.Lyngby 2800Denmark Center for Regenerative and Reconstructive Medicine Med-X InstituteThe First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061China Solid-State Lighting Engineering Research Center Xi’an Jiaotong UniversityXi’an 710049China

Microcavity photon dynamics in curved space is an emerging interesting area at the crossing point of nanophotonics,chaotic science,and non-Euclidean *** report the sharp difference between the regular and chaotic motions of cavity photons subjected to the varying space *** the island modes of regular motion rise in the phase diagram in the curved space,the chaotic modes show special mechanisms to adapt to the space curvature,including the fast diffusion of ray dynamics,and the localization and hybridization of the Husimi wavepackets among different periodic *** observations are unique effects enabled by the combination of the chaotic trajectory,the wave nature of light,and the non-Euclidean orbital motion,and therefore make the system a versatile optical simulator for chaotic science under quantum mechanics in curved space-time.

关键词： microcavity chaotic motion curved space

Influence of layer thickness on formation quality,microstructure,mechanical properties,and corrosion resistance of WE43 magnesium alloy fabricated by laser powder bed fusion

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Journal of Magnesium and Alloys 2024年第4期12卷 1367-1385页

作者： Bangzhao Yin Jinge Liu Bo peng Mengran Zhou Bingchuan Liu Xiaolin Ma Caimei wang peng Wen yun Tian Yufeng Zheng State Key Laboratory of Tribology in Advanced Equipment Beijing100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Institute for Precision Medicine Tsinghua UniversityBeijing102218China Department of Orthopaedics Peking University Third HospitalBeijing 100191China Beijing AKEC Medical Co. Ltd.Beijing 102200China School of Materials Science and Engineering Peking UniversityBeijing 100871China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing 100191China

Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical *** thickness(LT)is of great significance to the L-PBF process but has not been studied for Mg *** this study,WE43 Mg alloy bulk cubes,porous scaffolds,and thin walls with layer thicknesses of 10,20,30,and 40μm were *** required laser energy input increased with increasing layer thickness and was different for the bulk cubes and porous *** tended to occur at the connection joints in porous scaffolds for LT40 and could be eliminated by reducing the laser energy *** thin wall parts,a large overhang angle or a small wall thickness resulted in porosity when a large layer thicknesses was used,and the porosity disappeared by reducing the layer thickness or laser energy input.A deeper keyhole penetration was found in all occasions with porosity,explaining the influence of layer thickness,geometrical structure,and laser energy input on the *** the samples achieved a high fusion quality with a relative density of over 99.5%using the optimized laser energy *** increased layer thickness resulted to more precipitation phases,finer grain sizes and decreased grain *** the similar high fusion quality,the tensile strength and elongation of bulk samples were significantly improved from 257 MPa and 1.41%with the 10μm layer to 287 MPa and 15.12%with the 40μm layer,in accordance with the microstructural *** effect of layer thickness on the compressive properties of porous scaffolds was ***,the corrosion rate of bulk samples accelerated with increasing the layer thickness,mainly attributed to the increased number of precipitation phases.

关键词： Magnesium alloy WE43 Laser powder bed fusion Layer thickness Process optimization

Improving corrosion resistance of additively manufactured WE43 magnesium alloy by high temperature oxidation for biodegradable applications

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Journal of Magnesium and Alloys 2024年第3期12卷 940-953页

作者： Jinge Liu Bangzhao Yin Fei Song Bingchuan Liu Bo peng peng Wen yun Tian Yufeng Zheng Xiaolin Ma Caimei wang State Key Laboratory of Tribology in Advanced Equipment Beijing100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Department of Orthopaedics Beijing Tsinghua Changgung HospitalInstitute for Precision MedicineTsinghua UniversityBeijing102218China Department of Orthopaedics Peking University Third HospitalBeijing 100191China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing 100191China School of Materials Science and Engineering Peking UniversityBeijing 100871China Beijing AKEC Medical Co. Ltd.Beijing 102200China

Laser powder bed fusion(L-PBF)has been employed to additively manufacture WE43 magnesium(Mg)alloy biodegradable implants,but WE43 L-PBF samples exhibit excessively rapid *** this work,dense WE43 L-PBF samples were built with the relativity density reaching 99.9%.High temperature oxidation was performed on the L-PBF samples in circulating air via various heating temperatures and holding *** oxidation and diffusion at the elevated temperature generated a gradient structure composed of an oxide layer at the surface,a transition layer in the middle and the *** oxide layer consisted of rare earth(RE)oxides,and became dense and thick with increasing the holding *** matrix was composed ofα-Mg,RE oxides and Mg_(24)RE_(5) *** precipitates almost disappeared in the transition *** passivation effect was observed in the samples treated by a suitable high temperature *** original L-PBF samples lost 40%weight after 3-day immersion in Hank’s solution,and broke into fragments after 7-day *** casted and solution treated samples lost roughly half of the weight after 28-day *** high temperature oxidation samples,which were heated at 525℃ for 8 h,kept the structural integrity,and lost only 6.88%weight after 28-day *** substantially improved corrosion resistance was contributed to the gradient structure at the *** one hand,the outmost dense layer of RE oxides isolated the corrosive medium;on the other hand,the transition layer considerably inhibited the corrosion owing to the lack of ***,high temperature oxidation provides an efficient,economic and safe approach to inhibit the corrosion of WE43 L-PBF samples,and has promising prospects for future clinical applications.

关键词： Laser powder bed fusion Biodegradable magnesium alloy High temperature oxidation Corrosion resistance WE43.

Holographic Polymer Nanocomposites with High Refractive Index Modulation by Doping Liquid Crystal E6M

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Chinese Journal of Polymer Science 2024年第7期42卷 926-935,I0006页

作者： Meng-yun wang Yue Zhang Dan wang Ming Yao Yi-Xuan wang Xing-Ping Zhou Hai-Yan peng Xiao-Lin Xie Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China National Anti-counterfeit Engineering Research Center Huazhong University of Science and TechnologyWuhan430074China

Holographic optical elements(HOEs)based on polymer composites have become a research hot spot in recent years for augmented reality(AR)due to the significant improvement of optical performance,dynamic range,ease of processing and high yield ***,it remains a formidable challenge to obtain a large field of view(FOV)and brightness due to the limited refractive index ***,we report an effective method to tackle the challenge by doping an epoxy liquid crystal termed E6M,which enables a large refractive index modulation of 0.050@633 nm and low haze of 5.0%at a doping concentration of 5 wt%.This achievement may be ascribed to the improved molecular ordering of liquid crystals within the holographic polymer *** high refractive index modulation can endow transmission-type holographic polymer composites with a high diffraction efficiency of 96.2%at a small thickness of 5μm,which would promise the design of thin and lightweight AR devices.

关键词： Polymer nanocomposites Holography AR/VR Refractive index modulation Liquid crystal