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Covert LEO Satellite Communication Aided by Generative Adversarial Network Based Cooperative UAV Jamming

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China Communications 2024年第9期 27-39页

作者： Shi Jia Li Xiaomeng Liao Xiaomin tie zhuangzhuang Hu Junfan School of Communication Engineering Xidian University School of Information and Communications National University of Defense Technology

In this paper,we study the covert performance of the downlink low earth orbit(LEO) satellite communication,where the unmanned aerial vehicle(UAV) is employed as a cooperative *** maximize the covert rate of the LEO satellite transmission,a multi-objective problem is formulated to jointly optimize the UAV's jamming power and *** practical consideration,we assume that the UAV can only have partial environmental information,and can't know the detection threshold and exact location of the eavesdropper on the *** solve the multiobjective problem,we propose the data-driven generative adversarial network(DD-GAN) based method to optimize the power and trajectory of the UAV,in which the sample data is collected by using genetic algorithm(GA).Simulation results show that the jamming solution of UAV generated by DD-GAN can achieve an effective trade-off between covert rate and probability of detection errors when only limited prior information is obtained.

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Secrecy Transmission of NOMA-OTFS Based Multicast-Unicast Streaming

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China Communications 2023年第1期20卷 1-13页

作者： Junfan Hu Jia Shi Xianyu Wang Xiaoju Lu Zan Li zhuangzhuang tie Quanxue Gao The State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China Academy of Space Electronic Information Technology Xi’an 710100China Unit 69036 of PLA Urumqi 830000China

This paper investigates the security performance of a cooperative multicast-unicast system,where the users present the feature of high ***,we develop the non-orthogonal multiple access(NOMA)based orthogonal time frequency space(OTFS)transmission scheme,namely NOMAOTFS,in order to combat Doppler effect as well as to improve the spectral ***,we propose a power allocation method addressing the trade-off between the reliability of multicast streaming and the confidentiality of unicast *** on that,we utilize the relay selection strategy,to improve the security of unicast *** the context of multicastunicast streaming,our simulation findings validate the effectiveness of the NOMA-OTFS based cooperative transmission,which can significantly outperform the existing NOMA-OFDM in terms of both reliability and security.

关键词： OTFS NOMA physical layer security multicast-unicast

Alloy design for laser powder bed fusion additive manufacturing:a critical review

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International Journal of Extreme Manufacturing 2024年第2期6卷 29-63页

作者： zhuangzhuang Liu Qihang Zhou Xiaokang Liang Xiebin Wang Guichuan Li Kim Vanmeensel Jianxin Xie Key Laboratory for Advanced Materials Processing(MOE) Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083People’s Republic of China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Capital Aerospace Machinery Corporation Limited Beijing 100076People’s Republic of China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJingshi Road 17923Jinan 250061People’s Republic of China Department of Materials Engineering KU LeuvenLeuven 3001Belgium

Metal additive manufacturing(AM)has been extensively studied in recent *** the significant progress achieved in manufacturing complex shapes and structures,challenges such as severe cracking when using existing alloys for laser powder bed fusion(L-PBF)AM have *** challenges arise because commercial alloys are primarily designed for conventional casting or forging processes,overlooking the fast cooling rates,steep temperature gradients and multiple thermal cycles of *** address this,there is an urgent need to develop novel alloys specifically tailored for L-PBF *** review provides a comprehensive summary of the strategies employed in alloy design for *** aims to guide future research on designing novel alloys dedicated to L-PBF instead of adapting existing *** review begins by discussing the features of the L-PBF processes,focusing on rapid solidification and intrinsic heat ***,the printability of the four main existing alloys(Fe-,Ni-,Al-and Ti-based alloys)is critically assessed,with a comparison of their conventional *** was found that the weldability criteria are not always applicable in estimating ***,the review presents recent advances in alloy development and associated strategies,categorizing them into crack mitigation-oriented,microstructure manipulation-oriented and machine learning-assisted ***,an outlook and suggestions are given to highlight the issues that need to be addressed in future work.

关键词： laser powder bed fusion alloy design printability crack mitigation

An aircraft brake control algorithm with torque compensation based on RBF neural network

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Chinese Journal of Aeronautics 2024年第1期37卷 438-450页

作者： Ning BAI Xiaochao LIU Juefei LI zhuangzhuang WANG Pengyuan QI Yaoxing SHANG Zongxia JIAO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing 100191China Key Laboratory of Advanced Aircraft Systems(Beihang University) Ministry of Industry and Information TechnologyBeijing 100091China Research Institute for Frontier Science Beihang UniversityBeijing 100191China Ningbo Institute of Technology of Beihang University Ningbo 315800China Tianmushan Laboratory Xixi Octagon CityYuhang DistrictHangzhou 310023China

The wheel brake system of an aircraft is the key to ensure its safe landing and rejected takeoff.A wheel’s slip state is determined by the brake torque and ground adhesion torque,both of which have a large degree of *** is this nature that brings upon the challenge of obtaining high deceleration rate for aircraft brake *** overcome the disturbances caused by the above uncertainties,a braking control law is designed,which consists of two parts:runway surface recognition and wheel’s slip state *** runway surface recognition,the identification rules balancing safety and braking efficiency are defined,and the actual identification process is realized through recursive least square method with forgetting *** slip state tracking,the LuGre model with parameter adaptation and a brake torque compensation method based on RBF neural network are proposed,and their convergence are *** effectiveness of our control law is verified through simulation and ground *** in the experiments on the ground inertial test bench,compared to the improved pressure-biased-modulation(PBM)anti-skid algorithm,fewer wheel slips occur,and the average deceleration rate is increased by 5.78%,which makes it a control strategy with potential for engineering applications.

关键词： Aircraft landing Brakes Disturbance observer Neural networks Runway identification

Flexo-photocatalysis in centrosymmetric semiconductors

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Nano Research 2024年第3期17卷 1173-1181页

作者： Kang Liu Tong Wu Luying Xu zhuangzhuang Zhang Zhiyu Liu Longfei Wang Zhong Lin Wang Center on Nanoenergy Research School of Physical Science&TechnologyGuangxi UniversityNanning 530004China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China Georgia Institute of Technology AtlantaGA 30332-0245USA Yonsei Frontier Lab Yonsei UniversitySeoul 03722Republic of Korea

The separation of photogenerated electron–hole pairs is vitally important for photocatalysis,which can be effectively promoted by polarization ***,it only manifests in piezoelectric/pyroelectric/ferroelectric materials that have a non-centrosymmetric ***,we demonstrate that the polarization enhanced photocatalysis(with wide spectra from ultraviolet(UV)light to visible light)can be achieved in centrosymmetric semiconductors,such asδ-MnO_(2) and TiO_(2) nanosheets integrated nanoflowers,by using the strain-gradient-induced flexoelectric polarization that is always overlooked in polarization-enhanced *** ultrasonic and illumination excitation,the organic pollutants(methylene blue(MB),etc.)can be effectively degraded within 30 min with excellent stability and *** with photocatalysis,the flexo-photocatalytic performance of above centrosymmetric semiconductors is substantially increased by 85%.Moreover,the factors related to flexo-photocatalysis such as material morphology,mechanical stimuli source,and adsorption are explored to deeply understand the mechanism of *** work opens up a way for high-performance photocatalysis in centrosymmetric semiconductors.

关键词： piezo-photocatalysis photocatalysis flexoelectricity polarization centrosymmetric semiconductor

Effect of safety valve types on the gas venting behavior and thermal runaway hazard severity of large-format prismatic lithium iron phosphate batteries

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Journal of Energy Chemistry 2024年第2期89卷 195-207,I0006页

作者： zhuangzhuang Jia Yuanyuan Min Peng Qin Wenxin Mei Xiangdong Meng Kaiqiang Jin Jinhua Sun Qingsong Wang State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026AnhuiChina Gotion High-Tech Co. Ltd.Hefei 230012AnhuiChina

The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not *** this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under *** to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve *** significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy *** study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.

关键词： Lithium iron phosphate battery Safety valve Thermal runaway Gas venting behavior Thermal runaway hazard severity Gray-fuzzy analytic hierarchy process

Effect of Oxygen-Rich Combustion on Flame Propagation of Syngas in a Half-Open Pipe at Elevated Temperatures

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Journal of Thermal Science 2024年第5期33卷 1920-1934页

作者： LI Ningning DENG Haoxin XU zhuangzhuang YAN Mengmeng WEI Shengnan SUN Guangzhen WEN Xiaoping GAN Haowen WANG Fahui School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454003China

The investigation of syngas flame propagation has great benefits for the effective use of gas *** essay sets out to study the flame propagation of premixed oxygen-rich combustion(oxygen enrichment coefficient in volumeΩ:0.21,0.27,0.32,0.37)of syngas(H_(2):CO=2:8)in half-closed rectangular ducts at elevated temperatures(T:300 K,400 K,500 K)and evaluate the effects of initial temperature and oxygen enrichment coefficient on the LBV from sensitivity analysis and kinetic *** paper presents the effect of the expansion effect on laminar burning velocity for the first time,and separates the effect of the expansion effect on laminar burning velocity by a new *** shows that as the initial temperature goes up,the faster the exponential growth phase of the flame front velocity,the slower the slow growth *** smaller and earlier the maximum flame front velocity arrives,the slower the average flame speed *** the oxygen enrichment coefficient goes up,the peak value of the flame front velocity gradually ***-rich combustion and increasing initial temperature inhibit flame propagation in a half-open tube,but promote laminar burning velocity,which increases the key chemical bond and adiabatic flame *** net reaction rate shows that oxygen-rich combustion mainly promotes the combustion reaction of H_(2)(R2).However,increasing the initial temperature mainly promoted the oxidation of CO(R29).Analysis of the reaction path showed that oxygen-rich combustion and increased initial temperature promoted the reaction of H_(2)and CO with key chemical bonds,increased OH concentration,and inhibited OH cracking reaction.

关键词： gas turbines oxyfuel combustion numerical simulation combustion kinetics fire and flame

Laboratory Evaluation of Performance Recovery of Aged SBS-modified Asphalt Using Regenerants with Different Base Oil Components

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China Petroleum Processing & Petrochemical Technology 2024年第2期26卷 98-107页

作者： Li Hongzhen Li Shengbin Feng zhuangzhuang Jiang Mengmeng Li Ning Dong Fuqiang Shandong Yimeng Traffic Development Group Co. Ltd.Zibo 276004China College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China

In this study,the regenerative effects of different regenerants on aged SBS-modified asphalt from different perspectives were investigated,including their conventional properties,viscoelastic behavior,creep-related properties,and *** oils composed of different proportions of aromatic and saturated hydrocarbons as well as the styrene-butadiene-styrene(SBS)restorer were used to prepare the *** results showed that the components of the base oil of the regenerant played a crucial role in determining the characteristics and performance of the recycled SBSmodified *** containing a high proportion of aromatics dissolved the hard segment in the SBS restorer,thereby delaying the effect of a reduction in the regenerants on the performance of the aged asphalts at a high *** containing a high proportion of saturates dissolved the soft segment in the SBS restorer to enhance the lowtemperature performance of the recycled *** addition,the stress sensitivity of the recycled asphalts increased with the fraction of aromatics in the *** the aromatic content of the base oil components of the regenerants increased and their saturate content decreased,the state of dispersion of the SBS phase in the recycled SBS-modified asphalts *** optimal content of aromatics in the base oil of the regenerants should be set in the range of 33%to 47%to ensure the adequate performance of the recycled asphalts and a high efficiency of the SBS restorer.

关键词： aged SBS-modified asphalt regeneration mechanisms base oil rheological properties morphology

Identification of a novel MYO1D variant associated with laterality defects,congenital heart diseases,and sperm defects in humans

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Frontiers of Medicine 2024年第3期18卷 558-564页

作者： zhuangzhuang Yuan Xin Zhu Xiaohui Xie Chenyu Wang Heng Gu Junlin Yang Liangliang Fan Rong Xiang Yifeng Yang Zhiping Tan Department of Cardiovascular Surgery The Second Xiangya Hospital of Central South UniversityChangsha410011China Clinical Center for Gene Diagnosis and Therapy The Second Xiangya Hospital of Central South UniversityChangsha410011China Department of Cell Biology School of Life SciencesCentral South UniversityChangsha410013China Department of Gynecology and Obstetrics Xiangya Hospital of Central South UniversityChangsha410008China

The establishment of left–right asymmetry is a fundamental process in animal *** with this process leads to a range of disorders collectively known as laterality defects,which manifest as abnormal arrangements of visceral *** patients with laterality defects,congenital heart diseases(CHD)are *** multiple model organisms,extant research has established that myosin-Id(MYO1D)deficiency causes laterality *** study investigated over a hundred cases and identified a novel biallelic variant of MYO1D(NM_015194:c.1531G>A;p.D511N)in a consanguineous family with complex CHD and laterality *** examination of the proband revealed asthenoteratozoospermia and shortened ***,the effects of the D511N variant and another known MYO1D variant(NM_015194:c.2293C>T;p.P765S)were *** assessment showed that both enhance the interaction withβ-actin and ***,this study revealed the genetic heterogeneity of this rare disease and found that MYO1D variants are correlated with laterality defects and CHD in ***,this research established a connection between sperm defects and MYO1D *** offers guidance for exploring infertility and reproductive health *** findings provide a critical basis for advancing personalized medicine and genetic counseling.

关键词： MYO1D laterality defect congenital heart disease sperm defect β-actin SPAG6