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Magnetic Field Fluctuations in the Solar Wind, Foreshock and Magnetosheath:Cluster Data Analysis

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空间科学学报 2005年第5期25卷 368-373页

作者： j. du C. Wang X. X. Zhang N. N. Shevyre G. N. Zastenker Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Space Research Institute Russian Academy of Sciences Moscow Russia

46 magnetosheath crossing events from the two years (2001.2-2003.1) of Cluster magnetic field measurements are identified and used to investigate the characters of the magnetic field fluctuations in the regions of undisturbed solar wind, foreshock, magnetosheath. The preliminary results indicate the properties of the plasma turbulence in the magnetosheath are strongly controlled by IMF orientation with respect to the bow shock normal. The amplitude of the magnetic field magnitude and direction variations behind quasiparallel bow shock are larger than those behind quasi-perpendicular bow shock. Almost purely compressional waves are found in quasi-perpendicular magnetosheath.

关键词：太阳风磁场磁鞘行星

Upcycling the spent graphite/LiCoO_(2) batteries for high-voltage graphite/LiCoPO_(4)-co-workable dual-ion batteries

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International j.urnal of Minerals,Metallurgy and Materials 2024年第7期31卷 1745-1751页

作者： Miao du Hongyan Lü Kaidi du Shuohang Zheng Xiaotong Wang Xiaotong Deng Ronghua Zeng Xinglong Wu Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education Northeast Normal UniversityChangchun 130024China Faculty of Chemistry Northeast Normal UniversityChangchun 130024China School of Chemistry South China Normal UniversityGuangzhou 510006China

The worldwide proliferation of portable electronics has resulted in a dramatic increase in the number of spent lithium-ion batteries(LIBs).However,traditional recycling methods still have limitations because of such huge amounts of spent ***,we proposed an ecofriendly and sustainable double recycling strategy to concurrently reuse the cathode(LiCoO_(2))and anode(graphite)materials of spent LIBs and recycled LiCoPO_(4)/graphite(RLCPG)in Li^(+)/PF^(-)_(6) co-de/intercalation dual-ion *** recycle-derived dualion batteries of Li/RLCPG show impressive electrochemical performance,with an appropriate discharge capacity of 86.2 mAh·g^(-1) at25 mA·g^(-1) and 69%capacity retention after 400 *** recycling of the cathode and anode from spent LIBs avoids wastage of resources and yields cathode materials with excellent performance,thereby offering an ecofriendly and sustainable way to design novel secondary batteries.

关键词： recycle lithium cobalt oxide lithium cobalt phosphate graphite dual-ion batteries spent lithium-ion batteries

A photogrammetric approach for quantifying the evolution of rock j.int void geometry under varying contact states

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International j.urnal of Mining Science and Technology 2024年第4期34卷 461-477页

作者： Rui Yong Changshuo Wang Nick Barton Shigui du Institute of Rock Mechanics Ningbo UniversityNingbo 315211China Nick Barton&Associates Fjordveien 65cHøvik 1363Norway

Accurate measurement of the evolution of rock j.int void geometry is essential for comprehending the distribution characteristics of asperities responsible for shear and seepage ***,existing techniques often require specialized equipment and skilled operators,posing practical *** this study,a cost-effective photogrammetric approach is ***,local coordinate systems are established to facilitate the alignment and precise quantification of the relative position between two halves of a rock ***/pull tests are conducted on rock j.ints with varying roughness levels to induce different contact states.A high-precision laser scanner serves as a benchmark for evaluating the photogrammetry *** certain deviations exist,the measured evolution of void geometry is generally consistent with the qualitative findings of previous *** photogrammetric measurements yield comparable accuracy to laser scanning,with maximum errors of 13.2%for aperture and 14.4%for void *** j.int matching coefficient(j.C)measurement errors are below 20%.Larger measurement errors occur primarily in highly mismatched rock j.ints with j.C values below 0.2,but even in cases where measurement errors exceed 80%,the maximum j.C error is only ***,the proposed photogrammetric approach holds promise for widespread application in void geometry measurements in rock j.ints.

关键词： Rock j.int Void geometry evolution Photogrammetry Aperture Void volume j.int matching coefficient

Nonlinear uncertainty impact of geometric variations on aerodynamic performance of low-pressure turbine blades with ultra-high loading under extreme operational conditions

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Chinese j.urnal of Aeronautics 2024年第5期37卷 281-300页

作者： Xiaoj.ng WANG Zhengping ZOU Chao FU Pengcheng du School of Energy and Power Engineering Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

Uncertainty impact of random geometric variations on the aerodynamic performance of low-pressure turbine blades is considerable,which is further amplified by the current ultra-high-lift design trend for weight ***,this uncertainty impact on ultra-highly loaded blades under extreme operational conditions near the margins with potential large-scale open separation is focused on in this *** is demonstrated that this impact is significant,unfavourable,and nonlinear,which is clearly severer under extreme *** addition to the overall attenuation and notable scattering of specific performance,the operational margins with open separation are also notably scattered with great risk of significant *** scattering and nonlinearity are dominated by the variations in leading-edge *** thinning of leading edge triggers local transition,enhancing downstream friction and reducing resistance to open separation,which is further exacerbated by operational ***,the opposite thickening yields less benefit,implying *** unfavourable impact highlights the need for robust aerodynamic design,where both a safer operational condition and a more robust blade are indispensable,i.e.,a compromise among performance,weight,and *** the necessary limitation of loading levels,a mid-loaded design is recommended to reduce adverse pressure gradients in both the leading edge and rear region of the suction side,which helps to decrease the susceptibility of the transition and open separation to random *** improvements can also be achieved by appropriately thickening the leading edge.

关键词： Ultra-highly loaded turbine blade Geometric variations Uncertainty analysis Operational margins Robust aerodynamic design Nonlinearity

An improved high-fidelity adaptive model for integrated inlet-engine-nozzle based on mechanismdata fusion

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Chinese j.urnal of Aeronautics 2024年第8期37卷 190-207页

作者： Chen WANG Ziyang YU Xian du Ximing SUN School of Control Science and Engineering Dalian University of TechnologyDalian 116024China Key Laboratory of Intelligent Control and Optimization for Industrial Equipment Ministry of EducationDalian University of TechnologyDalian 116024China

Nowadays,there has been an increasing focus on integrated flight propulsion control and the inlet-exhaust design for the aero-propulsion *** component-level models are inadequate due to installed performance deviations and mismatches between the real engine and the model,failing to meet the accuracy requirements of supersonic *** paper establishes a quasi-one-dimensional model for the inlet-exhaust system and conducts experimental ***,a mechanism-data fusion adaptive modeling scheme using an Extreme Learning Machine based on the Salp Swarm Algorithm(SSA-ELM)is *** study reveals the inlet model’s efficacy in reflecting installed performance,flow matching,and mitigating pressure distortion,while the nozzle model accurately predicts flow coefficients and thrust coefficients,and identifies various operational *** model’s output closely aligns with typical experimental *** combining offline optimization and online adaptive correction,the mechanismdata fusion adaptive model substantially reduces output errors during regular flights and varying levels of degradation,and effectively handles gradual degradation within a single flight ***,the mechanism-data fusion adaptive model holistically addresses total pressure errors within the inlet-exhaust system and normal shock location *** approach significantly curbs performance deviations in supersonic *** example,at Ma=2.0,the system error impressively drops from 34.17%to merely 6.54%,while errors for other flight conditions consistently stay below the 2.95%*** findings underscore the clear superiority of the proposed method.

关键词： Aero-propulsion system Integrated inlet-enginenozzle Component-level model On-board adaptive model Mechanism-data fusion Extreme learning machine

Precise determination of the pole position of the exotic Z_(c)(3900)

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 84-90页

作者： Yun-Hua Chen Meng-Lin du Feng-Kun Guo School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China School of Physics University of Electronic Science and Technology of ChinaChengdu 611731China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China

We perform a unified description of the experimental data of the π^(+)π^(-)and j.ψπ^(±)invariant mass spectra for e^(+)e^(-)→j.ψπ^(+)π^(-)and the D^(0)D^(*-)mass spectrum for e^(+)e^(-)→D^(0)D^(*-)π^(+)at e^(+)e^(-)center-of-mass energies 4.23 and 4.26 *** analysis takes into account open-charm meson loops that contain triangle singularities,the j.ψπ-DD^(*)coupled-channel interaction respecting unitarity,and the strong ππ-KK final state interaction using dispersion *** analysis leads to a precise determination of the Z_(c)(3900)pole with the pole mass and width(3880.7±1.7_(stat)±22.4_(syst))MeV and(35.9±1.4_(stat)±15.3_(syst))MeV,respectively,and hints at that the DD^(*)molecular and non-molecular components are of similar importance in the Z_(c)(3900)formation.

关键词： exotic hadrons dispersion relations final state interaction triangle singularity

Influence of Vanes and Blades on Ingress in Axial Rim Seal for Turbine Stages

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j.urnal of Thermal Science 2024年第3期33卷 833-846页

作者： REN Ran du Qiang LIU Guang ZENG Yanlian XIE Lei Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Beijing100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing100190China

Hot gas ingestion refers to the phenomenon of mainstream hot gas flowing into the space cavity of a turbine *** studies have found that mainstream annulus pressure distribution plays an important role in hot gas ingestion,but due to its complexity,the mechanism of the interaction between mainstream flow and hot gas ingestion remains *** paper adopts the URANS method,and three sealing flow rates are considered,named C_(w)=0,C_(w)=500,and C_(w)=*** time-averaged annulus pressure distribution shows that an increase in the sealing flow decreases the pressure value,and the effects of the sealing flow on the pressure distribution of the leading edge of the blade are much more influential than that of the trailing edge of the *** unsteady pressure time-space distribution in the annulus indicates that a time-space tilted distribution of pressure at the rim exits when the sealing flow *** phenomenon is mainly due to the strong feedback mechanism of the sealing flow to the annulus pressure field.A comparison of the pressure and mean radial velocity distribution of the mainstream shows that the ingestion mainly occurs on the blade side,where the pressure is lower than on the vane *** flow characteristics at the wheel rim are analyzed with a sealing flow rate C_(w)=5000,and under these conditions,both pressure-induced ingestion and ingestion caused by a passage vortex can be *** three-dimensional and inertial effects of the mainstream at the wheel rim lead to the generation of separation vortices on the blade side,and the presence of separation vortices leads to ingestion along the blade *** the same time,pressure on the blade side will cause the fluid to have a radial inward flow tendency,which will promote the formation of separation vortices,leading to more serious ingestion in the high-pressure region on the blade *** blade pressure field can be more significant than the vane trailing pressure field in the rim sea

关键词： separation vortex unsteady rim seal the effect of blade on ingestion

Body-force modeling considering induced upstream effects for a transonic compressor with total temperature distortion

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Chinese j.urnal of Aeronautics 2024年第6期37卷 7-19页

作者： j.ahui QIU Chen YANG Wenqiang ZHANG Min ZHANG j.an du Digital Twin Research Center Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Engineering and Science University of Chinese Academy of SciencesBeijing 100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Chinese Academy of SciencesBeijing 100190China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

To numerically study the impact of total temperature distortion on a transonic compressor with reduced computational costs,a Body-Force Model(BFM)is ***,the interactions between the distorted flow and the compressor are analyzed using full-annulus Unsteady Reynolds-Averaged Navier-Stokes(URANS)results and the orbit *** is found that the induced swirl distortion and the mass flux nonuniformity are intensified in the compressor upstream flow field.A correction factor is thus added to the BFM to account for the effect of the induced swirl,which is crucial for the accurate representation of distortion transfer in the ***,steady simulations with large-amplitude 180circumferential total temperature distortion are performed using the developed *** is shown that the distorted compressor map simulated with the BFM matches well with URANS *** circumferential phase shift of total temperature and the generation of the additional total pressure distortion across the rotor are in line with the time-averaged URANS flow *** compressor upstream effects on the distorted inflow can also be exactly *** above-mentioned results demonstrate the BFM developed in this paper can effectively capture the distorted flow features inside the compressor,and significantly reduce the computational costs by five orders of magnitude compared with URANS.

关键词： Upstream effect Orbit method Induced swirl distortion Body force model Correction factor Time-averaged URANS

CRYSTALLOGRAPHIC PROPERTIES OF AN INHERENT LOW-ENERGY INTERFACE(1■1)Cu//(0001)_(AIN)IN Cu-AlN BICRYS

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Acta Metallurgica Sinica(English Letters) 1996年第4期9卷 235-239页

作者： j. du,G.Y.Yang and S. Hagegege(General Research Institute for Non-ferrous Metals, Beij.ng 100088, China)(CECM-CNRS,15 rue G. Urbain, 94407 Vitry/Seine, France )

A model Cu-AlN composite has been prepared by ion implantation technique and annealing. The atomic configuration and lattice relationship of a low-energy inherent interface(11)Cn//(0001)AlN were studied by using transmission electron microscopy and geometrical modelling. By analysing the dichromatic pattern of the composite,a primary structural unit of the interface atomic configuration was determined for purpose of HREM image simulations and of studying the structurul relaxation state in the near-interface region.

关键词： Cu-AlN,inherent interface symmetry structural unit