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Motion of the moonlet in the binary system 243 Ida

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Acta Mechanica Sinica 2018年第1期34卷 214-224页

作者： l.lan Y.Ni Y.jiang J.li School of Aerospace Engineering Tsinghua University State Key laboratory of Astronautic Dynamic Xi'an Satellite Control Center

The motion of the moonlet Dactyl in the binary system 243 Ida is investigated in this paper. First, periodic orbits in the vicinity of the primary are calculated, including the orbits around the equilibrium points and large-scale orbits. The Floquet multipliers’ topological cases of periodic orbits are calculated to study the orbits’ stabilities. During the continuation of the retrograde near-circular orbits near the equatorial plane, two period-doubling bifurcations and one Neimark–Sacker bifurcation occur one by one, leading to two stable regions and two unstable regions. Bifurcations occur at the boundaries of these regions. Periodic orbits in the stable regions are all stable, but in the unstable regions are all unstable. Moreover, many quasi-periodic orbits exist near the equatorial plane. long-term integration indicates that a particle in a quasi-periodic orbit runs in a space like a tire. Quasi-periodic orbits in different regions have different styles of motion indicated by the Poincare sections. There is the possibility that moonlet Dactyl is in a quasi-periodic orbit near the stable region I, which is enlightening for the stability of the binary system.

关键词： Binary system Bifurcation Periodic orbits Quasi-periodic orbits

Numerical study on the performance of nozzle flow for supersonic chemical oxygen-iodine lasers

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Acta Mechanica Sinica 2008年第2期24卷 133-142页

作者： Zongmin hu Junming lā Zonglin jiang Rho-Shin Myong Tae-hwan Cho lhD Institute of MechanicsCAS Beijing 100080 China Research Center for Aircraft Parts Technology Geyongsang National University Jinju 660-701 South Korea

laser performance is greatly dependent on its operating conditions due to the strong coupling among multi- physics such as gas-dynamics, chemical reaction kinetics and optics in the mixing nozzle of COIl. In this paper, 3D CFD technology is used to simulate the mixing and reactive flow of subsonic cross jet scheme at different conditions. Results obtained show that the jet penetration depth plays a dominant role in the spatial distribution of small signal gains. In the case of over-penetration, unsteady flow structures are induced by impinging between the opposing jets. The optimum spatial distribution of the chemical performance cannot be obtained even if the full penetration condition is achieved through the subsonic transverse jet mixing scheme in the COIl nozzle flow.

关键词： Chemical oxygen-iodine laser (COIl) Numerical simulation Small signal gains Unsteady structures

SIMUlATION OF ThE MAGNETIZATION REVERSAl PROCESS OF RECTANGlE-ShAPED NiFe FIlM ElEMENTS UNDER AN ORThOGONAl MAGNETIC FIElD

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Acta Metallurgica Sinica(English letters) 2005年第5期18卷 642-646页

作者： W.l. Zhang R.J. Tang W.X. Zhang B. Peng h. C. jiang h.W. Zhang School of Microelectronics and Solid-state Electronics University of Electronic Science and Technology of China Chengdu 610054 China

The magnetization reversal process of nano-size rectangle-shaped NiFe film elements with different aspect ratios have been investigated under the orthogonally applied magnetic fields by micromagnetic simulation. Different magnetization reversal modes can appear depending on whether the bias field is applied or not. When there is no bias field, double “C” state is the initial reversal state. however, when there is a bias field, “S” state is the starting mode. The larger the aspect ratio is, the larger the switching field is. But, when the aspect ratio is larger than 3, the increase of the switching field ceases. These results can provide useful information to the application of the patterned NiFe film with rectangular elements.

关键词： NiFe film element micromagnetics aspect ratio magnetization reversal,switching field

Understanding ductile-to-brittle transition of metallic glasses from shear transformation zone dilatation

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Theoretical & Applied Mechanics letters 2015年第5期5卷 200-204页

作者： M.Q.jiang G.Wilde F.jiang l.h.Dai State Key laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Institute of Materials Physics Westf?lische Wilhelms-Universit?t Münster State Key laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University

A theoretical model that takes into account the flee-volume aided cooperative shearing of shear transformation zones （STZs） is developed to quantitatively understand the ductile-to-brittle transition （DBT） of metallic glasses. The STZ dilatational strain is defined as the ratio of STZ-activated free volume to STZ volume itself. The model demonstrates that the STZ dilatational strain will increase drastically and exceed the characteristic shear strain of STZ as temperature decreases below a critical value. This critical temperature is in good agreement with the experimentally measured DBT temperature. Our results suggest that the DBT of metallic glasses is underpinned by the transition of atomic-cluster motions from STZ-tvpe rearrangements to dilatational processes （termed tension transformation zones （TrZs））.

关键词： Ductile-to-brittle transitionMetallic glassFractureShear transformation zoneTension transformation zone

Identification of Antarctic minke and killer whales with passive acoustic monitoring in Prydz Bay, Antarctica

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Journal of Oceanology and limnology 2022年第2期40卷 485-495页

作者： Ying jiang lian-Gang lÜ Zongwei lIU Chunmei YANG Jingsong GUO First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Key laboratory of Marine Science and Numerical Modeling Ministry of Natural ResourcesQingdao 266061China

Although four species of odontocete and four species of baleen whale have been recorded in Prydz Bay,their vocalizations have been rarely *** vocalizations were recorded during March 2017 in Prydz Bay,***-duck sounds,downsweeps,inverted“u”shape signals,whistles,pulsed sounds,and broadband clicks were ***-duck sounds and downsweeps were associated with Antarctic minke whales(Balaenoptera bonaerensis)based on visual *** between inverted“u”shape signals,biphonic calls,and clicks with vocalizations previously described for killer whales(Orcinus orca)lead us believe the presence of Antarctic killer *** to sound structures,signal characteristics,and recording location,Antarctic type C killer whales were the most probable candidates to produce these detected *** represent the fi rst detection of inverted“u”shape signals in Antarctic waters,and the fi rst report of Antarctic killer whale in Prydz Bay based on passive acoustic *** co-existence of Antarctic minke and killer whales may imply that minke whales can detect diff erences between the sounds of mammal-eating and fi sh-eating killer *** descriptions of these underwater vocalizations contribute to the limited body of information regarding the distribution and acoustic behavior of cetaceans in Prydz Bay.

关键词： passive acoustic monitoring inverted“u”shaped signal killer whale Antarctic minke whales Prydz Bay type C

Cutting force and specific energy for rotary ultrasonic drilling based on kinematics analysis of vibration effectiveness

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Chinese Journal of Aeronautics 2022年第1期35卷 376-387页

作者： Zhen lI Songmei YUAN jiang MA Jun ShEN Andre D.l.BATAKO College of Mechatronics and Control Engineering.Shenzhen University Shenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100083China The General Engineering&Techmology Research Institute Liverpool John Moores UniversitLiverpool L33AF.UK

Rotary ultrasonic drilling(RUD)has become an effective approach for machining advanced composites which are widely using in the field of *** cutting kinematics and the corresponding material removal mechanisms are distinct in different drilling areas during ***,these fundamentals have not been fully considered in the existing *** this research,two distinct forms of interaction induced by ultrasonic vibration were considered as impact-separation and vibratory lapping between the abrasives and *** the conditions to guarantee the effectiveness of these interactions were obtained to eliminate diminishing effects of ultrasonic *** on indentation fracture theory,the penetration depth of abrasives and the axial drilling force model was derived for *** verification tests of C/SiC composites resulted in a prediction error within 15%.Due to the minimal volume of material removed during each vibration cycle,the drilling force was more stable in vibration assisted *** specific drilling energy of RUD was firstly calculated based on the measured drilling *** was found the drilling parameters should be matched with vibration frequency and amplitude to make better usage of the advantages of ultrasonic vibration,which is critical in the vibration assisted processing of advanced materials.

关键词： Ceramic matrix composite Drilling force modelling Kinematics analysis Rotary ultrasonic drilling Specific drilling energy Vibration diminishing effect

Effect of lamellarization on the microstructure and mechanical properties of marine 10Ni5CrMoV steel

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International Journal of Minerals,Metallurgy and Materials 2025年第02期 402-413页

作者： Tao Zou Yanwu Dong Zhouhua jiang Shuyang Du Yushuo li School of Metallurgy Northeastern University Key laboratory of Rolling and Automation Northeastern University Key laboratory for Ecological Metallurgy of Multimetallic Ores (Ministry of Education) Northeastern University

Multistage heat treatment involving quenching(Q), lamellarizing(l), and tempering(T) is applied to marine 10Ni5CrMoV steel. The microstructure and mechanical properties were studied by multiscale characterizations, and the kinetics of reverse austenite transformation, strain hardening behavior, and toughening mechanism were further investigated. The lamellarized specimens possess low yield strength but high toughness, especially cryogenic toughness. lamellarization leads to the development of film-like reversed austenite at the martensite block and lath boundaries, refining the martensite structure and lowering the equivalent grain size. Kinetic analysis of austenite reversion based on the JMAK model shows that the isothermal transformation is dominated by the growth of reversed austenite,and the maximum transformation of reversed austenite is reached at the peak temperature(750°C). The strain hardening behavior based on the modified Crussard–Jaoul analysis indicates that the reversed austenite obtained from lamellarization reduces the proportion of martensite, significantly hindering crack propagation via martensitic transformation during the deformation. As a consequence, the QlT specimens exhibit high machinability and low yield strength. Compared with the QT specimen, the ductile–brittle transition temperature of the QlT specimens decreases from-116 to-130°C due to the low equivalent grain size and reversed austenite, which increases the cleavage force required for crack propagation and absorbs the energy of external load, respectively. This work provides an idea to improve the cryogenic toughness of marine 10Ni5CrMoV steel and lays a theoretical foundation for its industrial application and comprehensive performance improvement.

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MR damping design of the drive joints of the lunar-based extravehicular spacesuit booster mechanism

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Journal of Southeast University(English Edition) 2024年第4期40卷 410-416页

作者： lühongzhan Yang hai jiang Yu College of Mechanical Engineering Donghua UniversityShanghai 201620China

Considering the special walking behavior of astronauts on the lunar surface,to reduce the impact on their bones and improve safety during extravehicular operations and walking,a magnetorheological(MR)damping mechanism of power assisted transmission joint used in a new type spacesuit is *** order to improve the damping performance of the MR damper,the influence of the damper s structural parameters on both the output and dynamic adjustable range of the damping torque is *** to the theoretical mechanical model,the output damping torque is calculated,the finite element method is used to conduct numerical *** the same time,the structural parameters of the damper are optimized by the response surface *** results indicate that the simulated torque aligns with the theoretically designed torque,and the damping characteristics of the optimized structure are effectively improved by the response surface *** with the initial structure,the damping torque is increased by 10.8%,and the dynamic adjustable range is expanded by 52.9%.

关键词： extravehicular spacesuit magnetorheological flexible transmission damping characteristics

high throughput synthesis enabled exploration of CoCrFeNi-based high entropy alloys

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Journal of Materials Science & Technology 2022年第15期110卷 269-282页

作者： l.Zhao l.jiang l.X.Yang h.Wang W.Y.Zhang G.Y.Ji X.Zhou W.A.Curtin X.B.Chen P.K.liaw S.Y.Chen h.Z.Wang Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory of Metal Materials CharacterizationCentral Iron and Steel Research InstituteBeijing 100081China Institute for Advance Studies in Precision Materials Yantai UniversityYantai 264005China National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China laboratory for Multiscale Mechanics Modeling Ecole Polytechnique Federale de LausanneLausanne CH-1015Switzerland School of Engineering RMIT UniversityMelbourne 3046Australia Department of Materials Science and Engineering The University of Tennessee37996USA

To accelerate the exploration,screening,and discovery of structural high-entropy alloys with targeted properties,the newly developed high-Throughput hot-Isostatic-Pressing based Micro-Synthesis Approach(hT-hIP-MSA)is employed to efficiently synthesize and characterize 85 combinatorial alloys in a 13-principal element alloying *** Co Cr Fe Ni-based high entropy alloys span 1 quaternary,9 quinary,and 36 senary alloy systems,and their composition-structure-property relationships are characterized and analyzed experimentally and *** the single-phase FCC CoCrFeNi alloy base,with Mn,Cu,Ti,Nb,Ta,Mo,W,Al,and Si as principal element alloying additions,we find(1)the extended Mn solubility in the single-phase FCC CoCrFeNi-Mn_(x) alloys,(2)the destabilizing behavior for most of the quinary and senary alloys,and(3)the distinctive solid-solution-strengthening effects in the *** combining the computational methods,the hT-hIP-MSA can be systematic and economic to explore and refine the compositions,structures,and properties of structural high-entropy alloys.

关键词： high-entropy alloys high-throughput Composition-structure-property