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Pressure-induced instability and its coupled aeroelasticity of inflated pillow

Chinese Journal of Aeronautics 2022年第2期35卷 1-7页

作者： ji zhang Changguo WANG jiaming guo jiawei zhang National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Special Environments Harbin Institute of TechnologyHarbin 150080China b Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbin 150001China

A floating air weapon system(such as airborne floating mines)plays an important role in modern air defense operations.This paper focuses on aeroelastic characteristics of airborne floating mine named inflated pillow.Firstly,the dynamic deployable process of the pillow and characteristics of the local instability of the edge are studied,and the evolution mechanism of wrinkles and kinks is analyzed.Secondly,in the cruising stage,the fluid-structural-thermal coupling analysis is performed on the pillow,and the aeroelastic characteristics are studied.Thirdly,the shapepreserving effect of the inflated pillow during the“negative pressure”slow landing stage is evaluated.It is found that when the wind velocity is higher,the pillow has a collapsed instability(surface extrusion and contact),and when the wind velocity is lower,snap-through instability occurs.Finally,for the collapsed instability,a carbon fiber skeleton is added to discrete the large global collapsed fold into small local folds,thus achieving shape-preserving effect of pillow.For snapthrough instability,the critical internal pressure and different shape evolution under different wind velocity are evaluated.Through the analysis of the mechanical mechanism and control of the structural morphological evolution,it provides theoretical guidance for the application of the curved shell structure in floating air weapon system.

关键词： Aeroelastic analysis Fluid-structural-thermal coupling analysis Inflated pillow Kink Pressure-induced instability Wrinkle

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Energy-Efficient Full-Duplex UAV Relaying with Trajectory Optimization and Power Control in Maritime Communication Environments

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China Communications 2022年第12期19卷 216-231页

作者： Lili guo Xiaodong ji Shibing zhang School of Information Science and Technology Nantong UniversityNantong 226019China Nantong University Xinglin College Nantong 226236China

This paper solves an energy-efficient optimization problem of a fixed-wing unmanned aerial vehicle(UAV) assisted full-duplex mobile relaying in maritime communication environments.Taking the speed and the acceleration of the UAV and the information-causality constraints into consideration,the energy-efficiency of the system under investigation is maximized by jointly optimizing the UAV’s trajectory and the individual transmit power levels of the source and the UAV relay nodes.The optimization problem is non-convex and thus cannot be solved directly.Therefore,it is decoupled into two subproblems.One sub-problem is for the transmit power control at the source and the UAV relay nodes,and the other aims at optimizing the UAV s flight trajectory.By using the Lagrangian dual and Dinkelbach methods,the two sub-problems are solved,leading to an iterative algorithm for the joint design of transmit power control and trajectory optimization.Computer simulations demonstrated that by conducting the proposed algorithm,the flight trajectory of the UAV and the individual transmit power levels of the nodes can be flexibly adjusted according to the system conditions,and the proposed algorithm can achieve signiflcantly higher energy efficiency as compared with the other benchmark schemes.

关键词： UAV communication full-duplex relaying(FDR) energy-efficiency maritime communication

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Distinct microstructure and property evolution of 0.76(Bi_(0.5)Na_(0.5))TiO_(3)-0.24SrTiO_(3) ferroelectric ceramics synthesized with different TiO_(2) reactants

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Journal of Materials Science & Technology 2023年第20期151卷 73-79页

作者： jian guo ji zhang jing Wang Shan-Tao zhang National Laboratory of Solid State Microstructures College of Engineering and Applied Sciences&Jiangsu Key Laboratory of Artificial Functional Materials&Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China School of Materials Science and Engineering Nanjing University of Science&TechnologyNanjing 210094China State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

Single phase 0.76(Bi_(0.5)Na_(0.5))TiO_(3)–0.24SrTiO_(3) ferroelectric ceramics have been synthesized with homogenous anatase and hierarchical rutile TiO_(2) raw reactants(BNST-A and BNST-R).Either calcined powder persists the microstructure characteristics of raw reactants.As the result,when the sintering temperature increases from 1000 to 1200℃,the average grain size and density of BNST-A increase from 0.49 to 1.48μm and 5.02 to 5.61 g/cm^(3),while those of BNST-R from 0.86 to 1.44μm and 5.37 to 5.61 g/cm^(3).BNST-A illustrates a predominant ergodic relaxor state,and BNST-R prefers a non-ergodic relaxor state,as evidenced by the distinct polarization-electric field loops and current-electric field curves.Especially,such a distinct ferroelectric state is independent of sintering temperature.It is believed that the special hierarchical microstructure of rutile TiO_(2) reactant is beneficial to form denser ceramics with larger grains,and thus suppresses the contributions of polar nanoregions and defect-induced built-in field to ferroelectric property,leading to non-ergodic relaxor state.This work clearly demonstrates the nonnegligible effects of TiO_(2) reactants on the microstructure and properties of BNST ferroelectric ceramics.

关键词： BNST ferroelectric ceramics TiO_(2)raw reactants Microstructure and property evolution

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A Fully Actuated System Approach for Stabilization of Discrete-Time Multiple-Input Nonlinear Systems with Distinct Input Delays

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Journal of Systems Science & Complexity 2022年第2期35卷 670-687页

作者： WU Ai-guo zhang jie ji Youzhou Harbin Institute of Technology(Shenzhen) Shenzhen 518055China HIT Wuhu Robot Technology Research Institute Wuhu 241008China

In this paper,the problem of stabilization is considered for discrete-time multiple-input nonlinear systems with distinct input delays law based on the fully actuated system approach.In order to compensate the input delays,a prediction scheme is presented to predict future states based on the closed-loop linear system.Then,a stabilizing law is constructed for nonlinear delayed systems by replacing the future states in the control law for the corresponding delay-free systems with their prediction.Finally,numerical examples are given to verify the effectiveness of the proposed approach.

关键词： Fully actuated system approach input delays nonlinear systems prediction scheme

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A Direct Route to Tetrahydropyridazine Derivatives via DMAP-Catalyzed [4+2] Annulation of Allenoates with Arylazosulfones

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Chinese Journal of Chemistry 2023年第22期41卷 3031-3036,I0002页

作者： Xin ji Ziyang Li jinfeng zhang Yicheng zhang Ling-guo Meng Key Laboratory of Green and Precise Synthetic Chemistry and Applications Ministry of EducationSchool of Chemistry and Materials ScienceHuaibei Normal UniversityHuaibeiAnhui 235000China

Herein,a DMAP-catalyzed[4+2]annulation ofα-substituted allenoates with arylazosulfones is reported,which affords facile access to tetrahydropyridazine derivative in synthetically useful yields.This reaction features mild conditions and good functional group tolerance.Moreover,the resultant products can be readily transformed into pyridazin-3-one derivatives in the presence of DDQ.

关键词： DMAP [4+2]Cycloaddition Tetrahydropyridazihe derivatives Pyridazin-3-one derivatives Allenes Zwitterions N-Heterocycles

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Tetris-Style Stacking Process to Tailor the Orientation of Carbon Fiber Scaffolds for Efficient Heat Dissipation

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Nano-Micro Letters 2023年第9期15卷 310-324页

作者： Shida Han Yuan ji Qi zhang Hong Wu Shaoyun guo jianhui Qiu Fengshun zhang The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research Institute of Sichuan UniversityChengdu 610065People’s Republic of China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural University015-0055AkitaJapan Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900People’s Republic of China

As the miniaturization of electronic devices and complication of electronic packaging,there are growing demands for thermal interfacial materials with enhanced thermal conductivity and the capability to direct the heat toward heat sink for highly efficient heat dissipation.Pitch-based carbon fiber(CF)with ultrahigh axial thermal conductivity and aspect ratios exhibits great potential for developing thermally conductive composites as TIMs.However,it is still hard to fabricate composites with aligned carbon fiber in a general approach to fully utilize its excellent axial thermal conductivity in specific direction.Here,three types of CF scaffolds with different oriented structure were developed via magnetic field-assisted Tetris-style stacking and carbonization process.By regulating the magnetic field direction and initial stacking density,the self-supporting CF scaffolds with horizontally aligned(HCS),diagonally aligned and vertically aligned(VCS)fibers were constructed.After embedding the polydimethylsiloxane(PDMS),the three composites exhibited unique heat transfer properties,and the HCS/PDMS and VCS/PDMS composites presented a high thermal conductivity of 42.18 and 45.01 W m^(−1)K^(−1)in fiber alignment direction,respectively,which were about 209 and 224 times higher than that of PDMS.The excellent thermal conductivity is mainly ascribed that the oriented CF scaffolds construct effective phonon transport pathway in the matrix.In addition,fishbone-shaped CF scaffold was also produced by multiple stacking and carbonization process,and the prepared composites exhibited a controlled heat transfer path,which can allow more versatility in the design of thermal management system.

关键词： Carbon fiber Magnetic field Thermal management Thermally conductive composites

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Equiatomic 9-cation high-entropy carbide ceramics of the IVB,VB,and VIB groups and thermodynamic analysis of the sintering process

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Journal of Advanced Ceramics 2022年第7期11卷 1082-1092页

作者： Yuan QIN ji-Xuan LIU Yongcheng LIANG guo-Jun zhang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Institute of Functional Materials Donghua UniversityShanghai 201620China College of Science Donghua UniversityShanghai 201620China

The preparation of high-entropy(HE)ceramics with designed composition is essential for verifying the formability models and evaluating the properties of the ceramics.However,inevitable oxygen contamination in non-oxide ceramics will result in the formation of metal oxide impurity phases remaining in the specimen or even escaping from the specimen during the sintering process,making the elemental compositions of the HE phase deviated from the designed ones.In this work,the preparation and thermodynamic analysis during the processing of equiatomic 9-cation HE carbide(HEC9)ceramics of the IVB,VB,and VIB groups were studied focusing on the removing of the inevitable oxygen impurity existed in the starting carbide powders and the oxygen contamination during the powder mixing processing.The results demonstrate that densification by spark plasma sintering(SPS)by directly using the mixed powders of the corresponding single-component carbides will inhibit the oxygen-removing carbothermal reduction reactions,and most of the oxide impurities will remain in the sample as(Zr,Hf)O_(2)phase.Pretreatment of the mixed powders at high temperatures in vacuum will remove most part of the oxygen impurity but result in a remarkable escape of gaseous Cr owing to the oxygen-removing reaction between Cr_(3)C_(2)and various oxide impurities.It is found that graphite addition enhances the oxygen-removing effect and simultaneously prevents the escape of gaseous Cr.On the other hand,although WC,VC,and Mo2C can also act as oxygen-removing agents,there is no metal-containing gaseous substance formation in the temperature range of this study.By using the heat-treated powders with added graphite,equiatomic HEC9 ceramics were successfully prepared by SPS.

关键词： high-entropy(HE)carbide oxygen impurity carbothermal reduction reaction phase composition thermodynamic analysi

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Cosmology with fast radio bursts in the era of SKA

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 37-55页

作者： ji-guo zhang Ze-Wei Zhao Yichao Li jing-Fei zhang Di Li Xin zhang Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Key Laboratory of Cosmology and Astrophysics(Liaoning) Northeastern UniversityShenyang 110819China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China

We present a forecast of the cosmological parameter estimation using fast radio bursts(FRBs)from the upcoming Square Kilometre Array(SKA),focusing on the issues of dark energy,the Hubble constant,and baryon density.We simulate 105and 106localized FRBs from a 10-year SKA observation,and find that:(1)using 106FRB data alone can tightly constrain dark-energy equation of state parameters better than CMB+BAO+SNe,providing an independent cosmological probe to explore dark energy;(2)combining the FRB data with gravitational-wave standard siren data from 10-year observation with the Einstein Telescope,the Hubble constant can be constrained to a sub-percent level,serving as a powerful low-redshift probe;(3)using 106FRB data can constrain the baryon density?bh to a precision of~0.1%.Our results indicate that SKA-era FRBs will provide precise cosmological measurements to shed light on both dark energy and the missing baryon problem,and help resolve the Hubble tension.

关键词： fast radio burst cosmology dark energy the Hubble constant baryon density Square Kilometre Array

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Dynamic evolution of transposable elements,demographic history,and gene content of paleognathous birds

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Zoological Research 2021年第1期42卷 51-61页

作者： Zong-ji Wang Guang-ji Chen guo-jie zhang Qi Zhou Institute of Animal Sex and Development Zhejiang Wanli UniversityNingboZhejiang 315100China MOE Laboratory of Biosystems Homeostasis&Protection Life Sciences InstituteZhejiang UniversityHangzhouZhejiang 310058China Department of Neuroscience and Developmental Biology University of ViennaVienna 1090Austria BGI-Shenzhen Beishan Industrial ZoneShenzhenGuangdong 518083China State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan 650223China Section for Ecology and Evolution Department of BiologyUniversity of CopenhagenCopenhagen DK-2100Denmark Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunmingYunnan 650223China Center for Reproductive Medicine The Second Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhouZhejiang 310058China

Palaeognathae includes ratite and tinamou species that are important for understanding early avian evolution.Here,we analyzed the whole-genome sequences of 15 paleognathous species to infer their demographic histories,which are presently unknown.We found that most species showed a reduction of population size since the beginning of the last glacial period,except for those species distributed in Australasia and in the far south of South America.Different degrees of contraction and expansion of transposable elements(TE)have shaped the paleognathous genome architecture,with a higher transposon removal rate in tinamous than in ratites.One repeat family,AviRTE,likely underwent horizontal transfer from tropical parasites to the ancestor of little and undulated tinamous about 30 million years ago.Our analysis of gene families identified rapid turnover of immune and reproductionrelated genes but found no evidence of gene family changes underlying the convergent evolution of flightlessness among ratites.We also found that mitochondrial genes have experienced a faster evolutionary rate in tinamous than in ratites,with the former also showing more degenerated W chromosomes.This result can be explained by the Hill-Robertson interference affecting genetically linked W chromosomes and mitochondria.Overall,we reconstructed the evolutionary history of the Palaeognathae populations,genes,and TEs.Our findings of co-evolution between mitochondria and W chromosomes highlight the key difference in genome evolution between species with ZW sex chromosomes and those with XY sex chromosomes.

关键词： Paleognaths Demographic history Transposable elements Gene families Mitochondria

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中国9省区成年居民膳食模式研究

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中华流行病学杂志 2013年第1期34卷 37-40页

作者：张继国张兵王惠君王志宏杜文雯苏畅张伋翟凤英中国疾病预防控制中心营养与食品安全所公共营养与政策标准室北京100050

目的分析中国9省区成年居民的膳食模式。方法利用“中国健康与营养调查”资料，选取2009年调查中18～70岁健康成人作为研究对象，采用连续3天24小时膳食回顾询问法收集膳食资料。结果中国9省区成年男性居民有“稻米猪肉”、“水果蛋类... 详细信息

目的分析中国9省区成年居民的膳食模式。方法利用“中国健康与营养调查”资料，选取2009年调查中18～70岁健康成人作为研究对象，采用连续3天24小时膳食回顾询问法收集膳食资料。结果中国9省区成年男性居民有“稻米猪肉”、“水果蛋类”、“牛羊肉禽肉”和“小吃豆类”4种膳食模式，女性居民有“稻米猪肉”、“水果奶类”和“薯类杂粮”3种膳食模式。城乡地区是膳食模式的影响因素（男性4种膳食模式：β=-0．15324、-0．15324、0．37662、0．14810，P〈0．01；女性3种膳食模式：β=-0．13943、0．22200、-0．30836，P〈O．01）。结论中国9省区成年居民膳食模式存在性别差异。“稻米猪肉”模式是成年居民的主要膳食模式。

关键词：膳食模式因子分析成年居民

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