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Mechanism in Solidification of a Ternary Nickel Based Alloy

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 1018-1024页

作者：田密成博 School of aeronautical Manufacturing Industry Chengdu Aeronautical PolytechnicChengdu 610100China college of Mechanical Engineering North University of ChinaTaiyuan 030051China

The experiment employed the use of melt purification and cyclic superheating technique to achieve maximum undercooling of Ni65Cu31Co4 alloy at ***,high-speed photography techniques were used to capture the process of alloy liquid phase interface migration,and analyzed the relationship between the shape characteristics of the front end of alloy solidification and *** microstructure of the alloy was observed through metallographic microscopy,and the micro-morphological characteristics and evolution of the rapidly solidified microstructure were systematically *** is found that the grain refinement mechanism of Ni-Cu-Co ternary alloy is similar to that of Ni-Cu binary *** refinement at low undercooling is caused by intense dendritic remelting,while grain refinement at high undercooling is attributed to recrystallization,driven by the stress and plastic strain accumulated from the interaction of liquid flow and primary dendrites caused by rapid *** also shows that the addition of the third element Co plays a significant role in solidification rate and re-ignition effect.

关键词： undercooling recalescence Ni-Cu-Co ternary alloy grain refinement recrystallization

Construction of RuO2-Ru/MoO2@carbon cloth bifunctional electrocatalyst for efficient overall water splitting

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Rare Metals 2024年第10期43卷 5095-5104页

作者： Jia-Lin Cai Jing-Yi Fan Xu-Dong Zhang Xin Xie Wan-Yu Tian Xin-Gang Zhang Jie Ding Yu-Shan Liu college of Material Henan Key Laboratory of Aeronautical Materials and Application TechnologyZhengzhou University of Aeronautics The Green Catalysis Center and College of ChemistryZhengzhou University

Efficient bifunction electrocatalyst is extremely interesting for electrochemical overall water splitting （OWS）.Herein,a new RuO2-Ru/MoO2@CC（RRM/CC） bifunctional electrocatalyst was prepared via a solid phase reaction *** obtain a suitable precursor for SPR,MoS2nanosheets and RuO2nanoparticles （NPs）were sequentially loaded onto carbon cloth conductive ***,the prepared RuO2/MoS2/CC precursor was sealed in a furnace and annealed in Ar to trigger the redox *** SPR,active RuO2-Ru/MoO2units containing metal–metal oxide interfaces were formed on CC substrate *** optimized RRM/CC sample annealed at 400℃ exhibited a overpotential of 13 m V for hydrogen evolution reaction （HER） and 231 mV for oxygen evolution reaction （OER） at 10 mA·cm-2under alkaline condition,respectively,which can be deduced to the modulated electronic structure and unique hierarchica *** addition,a low cell voltage of 1.48 V for OWS was required at 10 mA·cm-2under alkaline condition Meanwhile,RRM/CC exhibited excellent pH-independent durability.

关键词： Bifunctional Electrocatalyst Overall water splitting Ru RuO2

Reduced-complexity multiple parameters estimation via toeplitz matrix triple iteration reconstruction with bistatic MIMO radar

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Chinese Journal of Aeronautics 2024年第7期37卷 482-495页

作者： Chenghong ZHAN Guoping HU Junpeng SHI Fangzheng ZHAO Hao ZHOU Graduate college Air Force Engineering UniversityXi’an 710051China Air and Missile Defense college Air Force Engineering UniversityXi’an 710051China college of Electronic Countermeasure National University of Defense TechnologyHefei 230037China Beijing aeronautical Technology Research Center Beijing 100076China

In this advanced exploration, we focus on multiple parameters estimation in bistatic Multiple-Input Multiple-Output(MIMO) radar systems, a crucial technique for target localization and imaging. Our research innovatively addresses the joint estimation of the Direction of Departure(DOD), Direction of Arrival(DOA), and Doppler frequency for incoherent targets. We propose a novel approach that significantly reduces computational complexity by utilizing the TemporalSpatial Nested Sampling Model(TSNSM). Our methodology begins with a multi-linear mapping mechanism to efficiently eliminate unnecessary virtual Degrees of Freedom(DOFs) and reorganize the remaining ones. We then employ the Toeplitz matrix triple iteration reconstruction method, surpassing the traditional Temporal-Spatial Smoothing Window(TSSW) approach, to mitigate the single snapshot effect and reduce computational demands. We further refine the highdimensional ESPRIT algorithm for joint estimation of DOD, DOA, and Doppler frequency, eliminating the need for additional parameter pairing. Moreover, we meticulously derive the Cramér-Rao Bound(CRB) for the TSNSM. This signal model allows for a second expansion of DOFs in time and space domains, achieving high precision in target angle and Doppler frequency estimation with low computational complexity. Our adaptable algorithm is validated through simulations and is suitable for sparse array MIMO radars with various structures, ensuring higher precision in parameter estimation with less complexity burden.

关键词： MIMO Radar Multipleparameters estimation Temporal-spatial Nested Sampling Multi-linear mapping mechanism Toeplitz matrix triple iteration reconstruction Reduce computational complexity

Hazardous Attitude Factors Influence Risk Perception in General Aviation Pilots

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Advances in Aerospace Science and Technology 2024年第3期9卷 85-93页

作者： Athina Holmes aeronautical Science Department College of Aviation Embry-Riddle Aeronautical University Daytona Beach FL USA

This manuscript presents a research proposal to investigate how hazardous attitudes among general aviation pilots influence pilot performance in aviation accidents. General aviation pilots train to maintain safe flying conditions, but accidents still occur, and human factors figure prominently among the causes of aviation accidents. The levels of hazardous attitudes among pilots may influence the likelihood of engaging in risky flight behaviors that can lead to accidents. This quantitative study aims to determine whether dangerous attitudes impact risk perception in general aviation pilots. The study will focus on two specific hazardous attitudes, “Anti-Authority” and Macho” behaviors. Among the hazardous attitudes identified by the Federal Aviation Administration (FAA), the two attitudes often stand out in accident investigations and pilot narratives. While all hazardous attitudes have inherent dangers, these two attitudes tend to be more frequently cited in accident reports and investigations. Despite rigorous training in safe flying conditions, general aviation accidents still transpire due to human factors. This research hypothesizes that the five attitudes from the hazardous attitude model, particularly Anti-Authority and Macho, significantly shape pilots’ risk perception. The insights from this study would benefit stakeholders, like the Aircraft Owners and Pilots Association (AOPA), Air Safety Institute, and aviation training programs, in creating training modules tailored to reduce such attitudes.

关键词： General Aviation (GA) Pilot Aviation Safety Hazardous Attitudes Anti-Authority Macho Risk Perception Flight Training

Three-Soliton Interactions and the Implementation of Their All-Optical Switching Function

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Chinese Physics Letters 2024年第4期41卷 51-58页

作者：伊厚会张鑫石领先姚延立王树斌马国利 School of Intelligent Manufacturing Weifang University of Science and TechnologyWeifang 262700China Institute of aeronautical Engineering Shandong University of AeronauticsBinzhou 256603China Flight college Shandong University of AeronauticsBinzhou 256603China Tianjin Sino-German University of Applied Sciences Tianjin 300350China

As a key component in all-optical networks,all-optical switches play a role in constructing all-optical *** to the absence of photoelectric conversion,all-optical networks can overcome the constraints of electronic bottlenecks,thereby improving communication speed and expanding their communication *** study all-optical switches based on the interactions among three optical *** analytically solving the coupled nonlinear Schr¨odinger equation,we obtain the three-soliton solution to the *** discuss the nonlinear dynamic characteristics of various optical solitons under different initial ***,we analyze the influence of relevant physical parameters on the realization of all-optical switching function during the process of three-soliton *** relevant conclusions will be beneficial for expanding network bandwidth and reducing power consumption to meet the growing demand for bandwidth and traffic.

关键词： soliton expanding networks

Transient state analysis of a rub-impact rotor system during maneuvering flight

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Chinese Journal of Aeronautics 2024年第7期37卷 236-251页

作者： Jun WANG Yunfei LIU Zhaoye QIN Liang MA Fulei CHU Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End Machinery Equipment Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China college of aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

Maneuvering flight substantially affects the dynamic behavior of rotors;particularly,such flight may cause rubbing between a rotor and stator,which is one of the most serious damages in aircraft *** this paper,a nonlinear dynamic model for describing the dynamic characteristics of a rub-impact rotor system during maneuvering flight is established based on the Lagrange ***,numerical simulations employing the Newmark method are performed,delving into the detailed discussion of the influence of parameters such as rotational speed and maneuvering flight on the transient and steady-state responses of the rotor *** effect mechanism of maneuver load and its coupling with rub impact is *** results show that the impact response induced by maneuvering flight is more obvious in the subcritical state than in the supercritical *** additional stiffness and damping are also induced;in particular,the additional damping has a coupling ***,the rub impact imposes an additional constraint on the rotor system,thereby weakening the influence of the maneuver load and becoming the major factor that determines the dynamic behavior of the rotor system at high speeds.

关键词： Maneuvering flight Rub impact Rotor system Dynamic response Impact response

Numerical study on influence of protrusion heights on Reynolds stress and viscous stress variations in turbulent vortical structures

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Chinese Journal of Aeronautics 2024年第9期37卷 59-71页

作者： Zhiping LI Long HE Jingsai ZHOU Yueren ZUO Yao YIN Peng ZHANG Bo MENG Research Institute of Aero-Engine Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBejing 100191China Institute of Acoustics Chinese Academy of SciencesBeijing 100190China college of aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China AECC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China

Analysing the infuence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet ***,the Large Eddy Simulation(LES)is used to investigate the vortex structure over the rib-let surface with different protrusion ***,the variations of Reynolds stress and viscous shear stress in a turbulent channel are *** a result,the drag reduction rate increases from 3.4%when the riblets are completely submerged in the turbulent boundary layer to 7.9%when the protrusion height is *** analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices,thus driving the variation of Reynolds *** with the smooth surface,the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion ***,the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height,and the normal diffusivity of normal vorticity is the smallest when the protrusion height is ***,the protrusion height affects the velocity gradient of the riblet tip and riblet valley,thus driving the variation of viscous shear *** the increase of protrusion height,the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.

关键词： Riblet Dragreduction Protrusion height Vortical structure Vortexdiffusivity Reynolds stress Viscous stress

CMAS-phobic and infiltration-inhibiting protective layer material for thermal barrier coatings

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Journal of Advanced Ceramics 2024年第8期13卷 1254-1267页

作者： Shjun Meng Lei Guo Hongbo Guo Yuanpeng Wang Hongli Liu School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin300072China School of Materials Science and Engineering Beihang UniversityBeijing 100191China college of aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

Calcium-magnesium-alumina-silicate(CMAS)corrosion has attracted special attention in the thermal barrier coating(TBC)*** high temperatures,when CMAS melts,it adheres to the coating surface and penetrates the interior,severely destroying the *** this study,a promising CMAS-phobic and infiltration-inhibiting material,GdPO4,on which molten CMAs is difficult to wet and penetrate,was *** desirable attributes are explained by analyzing the material characteristics of GdPO_(4) and its interfacial reaction with ***4 is demonstrated to have low surface energy,making it difficult for molten CMAS to wet and adhere to the *** in contact with molten CMAS,a double-layer structured reaction layer consisting of an acicular upper sublayer and a compact lower sublayer is formed on the GdPO4 surface,which can effectively impede molten CMAS spreading and ***-principles calculation results revealed that the reaction layer has low surface energy and low adhesion to CMAS,which are favorable for molten CMAS ***,the formation of the reaction layer increases the viscosity of the molten CMAS,which can increase melt wetting and ***,GdPO4,which exhibits excellent CMAS-phobicity and infiltration-inhibiting ability,is a promising protective layer material for TBCs against CMAS adhesion and attack.

关键词： thermal barrier coatings(TBCs) calcium-magnesium-alumina-silicate(CMAS)-phobicity GdPO_(4) interface reaction layer first-principles calculation

Bipolar Thermally Activated Delayed Fluorescence Emitter with Balanced Carrier Transport for High-Efficiency Nondoped Green Electroluminescent Devices

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CCS Chemistry 2024年第9期6卷 2346-2357页

作者： Yuchao Liu Zhagen Miao Haikuo Gao Shian Ying Can Gao Shouke Yan Huanli Dong Zhongjie Ren Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-PlasticsSchool of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao 266042 National Laboratory for Molecular Sciences Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190 Department of Chemistry University of Chinese Academy of SciencesBeijing 100049 Shandong Engineering Research Center of aeronautical Materials and Devices College of Aeronautical EngineeringBinzhou UniversityBinzhou 251900 State Key Laboratory of Chemical Resource Engineering College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029

High-efficiency electroluminescent devices featuring simplified architecture have received considerable attention due to significant advantages in construction procedures and commercialized ***,there still remains a critical challenge with regard to the lack of organic semiconductors that simultaneously possess high luminescent efficiency and balanced carrier-transporting ***,we design a thermally activated delayed fluorescence(TADF)emitter 4-(9,9-dimethyl-9,10-dihydroacridine)-4′-triphenylphosphineoxide-benzophenone(DMAC-BPTPO)by incorporating triphenylphosphine oxide into the donor–acceptor *** accessional electrontransporting moiety,rod-like dimer,and horizontally packing model synergistically enable DMAC-BP-TPO which possesses an excellent photoluminescence quantum yield of nearly 90%with a reverse intersystem crossing rate constant of 2.0×106 s−1,horizontal dipole ratio of 89%,and a balanced electron and hole mobilities with a small constrast ratio of ***,simplified electroluminescent devices including organic lightemitting diodes(OLEDs)and organic light-emitting transistors(OLETs)incorporating DMAC-BP-TPO-based nondoped film are demonstrated due to their superior integrated optoelectronic properties along with preferable horizontal dipole orientation.A record-high external quantum efficiency value of 21.7%and 4.4%are finally achieved in the simplified nondoped OLED and OLET devices,which are among the highest values in the related research *** work provides a new avenue to develop a high-efficiency bipolar TADF emitter to advance the simplified electroluminescent devices.

关键词： organic light-emitting diode organic lightemitting transistor bipolar thermally activated delayed fluorescence nondoped active layer