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Demand Prediction Based Slice Reconfiguration Using Dueling Deep Q-Network

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China Communications 2022年第5期19卷 267-285页

作者： Wanqing guan Haijun zhang School of Computer&Communication Engineering University of Science and Technology BeijingBeijing 100083China Beijing Engineering and Technology Research Center for Convergence Networks and Ubiquitous Services Institute of Artificial IntelligenceUniversity of Science and Technology BeijingBeijing 100083China

To satisfy diversified service demands of vertical industries,network slicing enables efficient resource allocation of a common infrastructure by creating isolated logical ***,uncertainty and dynamics of service demands will cause performance *** to operation costs and resource constraints,it is challenging to maintain high quality of user experience while obtaining high revenue for service providers(SPs).This paper develops an optimal and fast slice reconfiguration(OFSR)framework based on reinforcement learning,where a novel scheme is proposed to offer optimal decisions for reconfiguring diverse slices.A demand prediction model is proposed to capture changes in resource requirements,based on which the OFSR scheme is triggered to determine whether to perform slice *** the large state and action spaces generated from uncertain service time and resource requirements,deep dueling architecture is adopted to improve the convergence *** simulations validate the effectiveness of the proposed framework in achieving higher long-term revenue for SPs.

关键词： network slicing slice reconfiguration reinforcement learning resource allocation

Pressure infiltration of molten aluminum for densification of environmental barrier coatings

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Journal of Advanced Ceramics 2022年第1期11卷 145-157页

作者： Lin DONG Mei-jun LIU Xiao-Feng zhang Xue-Shi ZHUO Jia-Feng FAN guan-jun YANG Ke-Song ZHOU State Key Laboratory for Mechanical Behavior ofMaterials School ofMaterials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China National Engineering Laboratory for Modern Materials Surface Engineering Technology Institute of New MaterialsGuangdong Academy of ScienceGuangzhou 510650China

Environmental barrier coatings(EBCs)effectively protect the ceramic matrix composites(CMCs)from harsh engine environments,especially steam and molten ***,open pores inevitably formed during the deposition process provide the transport channels for oxidants and corrosives,and lead to premature failure of *** research work proposed a method of pressure infiltration densification which blocked these open pores in the *** results showed that it was difficult for aluminum to infiltrate spontaneously,but with the increase of external gas pressure and internal vacuum simultaneously,the molten aluminum obviously moved forward,and finally stopped infiltrating at a depth of a specific *** on the wrinkled zigzag pore model,a mathematical relationship between the critical pressure with the infiltration depth and the pore intrinsic geometry was *** infiltration results confirmed this relationship,indicating that for a given coating,a dense thick film can be obtained by adjusting the internal and external gas pressures to drive a melt infiltration.

关键词： infiltration process channel pore densification pressure assistant environmental barrier coating(EBC)

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高等院校科研成果转化工作分析

天津工业大学学报 2001年第2期20卷 50-53页

作者：王琥许增朴贾士儒关章军刘风琴天津轻工业学院天津300222

科研成果转化困难已成为高校科研工作的一个突出问题 .加速高校科技成果的转化是我国实施科教兴国战略的最迫切工作之一 .

关键词：高等学校科研成果转化工作转化率实施策略

Effect of mixing temperature on microstructure of an Al-Si alloy prepared by controlled diffusion solidification

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China Foundry 2023年第3期20卷 241-252页

作者： Han Xue Ti-jun Chen Xue-zheng zhang guang-li Bi Ying Ma Ren-guo guan State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina

The effects of mixing temperature,i.e.,the temperatures of two precursor melts(pure Al and Al-12Si),on the temperature and solute fields of resultant mixture,the nucleation and growth,and the size and morphology of primary grains during controlled diffusion solidification(CDS) of Al-8Si alloy were investigated by using simulation and *** results indicate that a lower mixing temperature is helpful for achieving more supercooled microscale Al-rich pockets in the mixture,and increasing the width and supercooling degree of supercooling zone in the Al-rich pockets,and thus,the nucleation *** nuclei grow up in nondendritic mode,resulting in spheroidal,at least,nondendritic *** a successful CDS,the superheat degrees of the two precursor melts should be limited within several degrees,and it is not necessary to extra stipulate the superheat degree of target alloy melt(Al-8Si) when the requirement about Gibbs energies of the three melts is *** observation on casting microstructures shows that the employed simulation and calculation processes are reasonable and the achieved results are reliable.

关键词： controlled diffusion solidification Al-Si alloy nucleation and growth supercooling nondendritic grains

Aircraft conflict resolution method based on hybrid ant colony optimization and artificial potential field

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Science China(Information Sciences) 2018年第12期61卷 190-192页

作者： Huaxian LIU Feng LIU Xuejun zhang Xiangmin guan jun CHEN Pascal SAVINAUD School of Electronic and Information Engineering Beihang University National Key laboratory of Communication Navigation Surveillance and Air Traffic Management (CNS/ATM )Beihang University Department of General Aviation Civil Aviation Management Institute of China School of Engineering and Materials Science Queen Mary University of London

Dear editor,With the significant growth of the civil aviation industry and especially its rapid development in booming economies such as that of China, air traffic flow is drastically increasing, leading to greater congestion around airport terminal areas and in busy airspace [1]. The substantial increase in air traffic flow has intensified the risk of violating safe separation regulations, endangering the airspace operational safety. Furthermore, as the result of

关键词： Figure Aircraft conflict resolution method based on hybrid ant colony optimization and artificial potential field

Solid dust induced roughening and overheating of TBC-coated superalloy

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Journal of Materials Science & Technology 2024年第13期180卷 69-79页

作者： Jia-Qi Han Mei-jun Liu Javad Mostaghimi guan-jun Yang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi'an Jiaotong UniversityXi'an 710049China Department of Mechanical and Industrial Engineering University of TorontoTorontoON M5S 3G8Canada

Thermal barrier coatings(TBC)on superalloy blade/vane enable an increase in turbine inlet temperature(TIT)and aero-engine ***,the deposition of dust on TBC significantly ablates superalloys and becomes a bottleneck for advanced engine *** paper presents a comprehensive mod-eling approach,based on an experiment involving dust deposition on a TBC-coated substrate,aimed at understanding the fundamental cause of substrate *** results show that a significant increase in surface roughness is obtained experimentally with dust *** temperature field within the TBC-substrate system is disturbed by surface ***,the film cooling is seriously *** the dust accumulated on the TBC surface also contributes to heat insulation by increas-ing the effective TBC thickness,localized overheating of the substrate occurs and then leads to ablation and premature failure of the *** elucidation of the overheating mechanism could inform the development of strategies to resist dust accumulation in advanced aero engines.

关键词： Thermal barrier coating Superalloy Dust Roughness Overheating

Comparative transcriptome analysis on the alteration of gene expression in ayu （Plecoglossus altivelis）larvae associated with salinity change

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Zoological Research 2016年第3期37卷 126-135页

作者： Xin-Jiang LU Hao zhang guan-jun YANG Ming-Yun LI Jiong CHEN Laboratory of Biochemistry and Molecular Biology School of Marine Sciences Ningbo University Ningbo 315211 China Collaborative Innovation Center for Zhejiang Marine High-Efficiency and Healthy Aquaculture Ningbo University Ningbo 315211 China

Ayu （Plecoglossus altivelis） fish, which are an amphidromous species distributed in East Asia, live in brackish water （BW） during their larval stage and in fresh water （FW） during their adult stage. In this study, we found that FW-acclimated ayu larvae exhibited a slower growth ratio compared with that of BW-acclimated larvae. However, the mechanism underlying FW acclimation on growth suppression is poorly known. We employed transcriptome analysis to investigate the differential gene expression of FW acclimation by RNA sequencing. We identified 158 upregulated and 139 downregulated transcripts in FW-acclimated ayu larvae compared with that in BW-acclimated larvae. As determined by Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway mapping, functional annotation of the genes covered diverse biological functions and processes, and included neuroendo- crinology, osmotic regulation, energy metabolism, and the cytoskeleton. Transcriptional expression of several differentially expressed genes in response to FW acclimation was further confirmed by real-time quantitative PCR. In accordance with transcriptome analysis, iodothyronine deiodinase （ID）, pro-opiom- elanocortin （POMC）, betaine-homocysteine S-meth- yltransferase 1 （BHMT）, fructose-bisphosphate aldolase B （aldolase B）, tyrosine aminotransferase （TAT）, and Na＋-K＋ ATPase （NKA） were upregulated after FW acclimation. Furthermore, the mRNA expressions of b-type natriurefic peptide （BNP） and transgelin were downregulated after FW acclimation. Our data indicate that FW acclimation reduced the growth rate of ayu larvae, which might result from the expression alteration of genes related to endocrine hormones, energy metabolism, and direct osmoregulation.

关键词： Plecoglossus altivelis Salinity change Transcriptome analysis Growth rate Real-time quantitative PCR

A survey of safety separation management and collision avoidance approaches of civil UAS operating in integration national airspace system

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Chinese Journal of Aeronautics 2020年第11期33卷 2851-2863页

作者： Xiangmin guan Renli LYU Hongxia SHI jun CHEN Department of General Aviation Civil Aviation Management Institute of ChinaBeijing 100102China General Aviation Institute of Zhejiang JianDe Hangzhou 311600China School of Engineering and Materials Science Queen Mary University of LondonLondon E14NSUnited Kingdom

Recent years have witnessed a booming of the industry of civil Unmanned Aircraft System(UAS).As an emerging industry,the UAS industry has been attracting great attention from governments of all countries and the aviation *** are highly digitalized,informationized,and intelligent;therefore,their integration into the national airspace system has become an important trend in the development of civil ***,the complexity of UAS operation poses great challenges to the traditional aviation regulatory system and technical *** to prevent collisions between UASs and between UAS and manned aircraft to achieve safe and efficient operation in the integrated operating airspace has become a common challenge for industry and academia around the *** recent years,the international community has carried out a great amount of work and experiments in the air traffic management of UAS and some of the key *** paper attempts to make a review of the UAS separation management and key technologies in collision avoidance in the integrated airspace,mainly focusing on the current situation of UAS Traffic Management(UTM),safety separation standards,detection system,collision risk prediction,collision avoidance,safety risk assessment,etc.,as well as an analysis of the bottlenecks that the current researches encountered and their development trends,so as to provide some insights and references for further research in this ***,this paper makes a further summary of some of the research highlights and challenges.

关键词： Air transportation Collision avoidance Safety Separation control Unmanned aircraft system

Towards developing Mg alloys with simultaneously improved strength and corrosion resistance via RE alloying

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Journal of Magnesium and Alloys 2021年第1期9卷 41-56页

作者： Jinshu Xie Jinghuai zhang Zihao You Shujuan Liu Kai guan Ruizhi Wu jun Wang Jing Feng Key Laboratory of Superlight Material and Surface Technology Ministry of EducationCollege of Material Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Department of Materials Physics and Chemistry Harbin Institute of TechnologyHarbin 150001China Department of Materials Science and Engineering University of TokyoTokyoJapan Ningbo Branch Ordnance Science Institute of ChinaNingbo 315103China

Magnesium(Mg)alloys have received an increasing interest in the past two decades for their tremendous application *** strength and corrosion resistance levels of common Mg alloys are still relativity low,and especially they are to be improved *** addition of rare earth(RE)to Mg alloys is believed to be beneficial for both the strength and corrosion resistance,and some RE-modified traditional Mg alloys have been studied and some new RE-containing Mg alloys have been developed by ***,further simultaneous improvements in both strength and anti-corrosion require a better understanding of the behavior and mechanism of RE in Mg *** this review,the common influence mechanisms of RE on mechanical and anti-corrosion properties of Mg alloys are summarized,and the latest research progress of RE-containing Mg alloys with simultaneously improved strength and corrosion resistance are *** is demonstrated that the research on high-strength and high corrosion resistant RE-containing Mg alloys is still immature,and some opinions and suggestions are put forward for the synergetic improvement of the strength and corrosion resistance of Mg alloys,so as to contribute to the further development of Mg alloys with higher performance.

关键词： Mg alloy Rare earth(RE) High strength Corrosion resistance