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Cold compression deformation method for reducing residual stress and uniformizing micro-property in ferrite steel

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Journal of Iron and Steel Research International 2022年第3期29卷 503-511页

作者： Bo ning hui-bin Wu Gang Niu Xin-pan Yu Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing100083China

To reduce internal residual stress and homogenize micro-property of hot-rolled ferrite steel,the cold compression deformation method with small reduction rate has been performed in the hot-rolled samples,and X-ray diffraction and nanoindentation test have been used to detect the residual stress and *** samples with deformation rate of 0-5.59%or annealing at 550℃ are *** results show that,due to the coupling effect of thermal expansion and cold contraction and the volume expansion of microstructural transformation from austenite to ferrite,compressive residual stress was found inside the hot-rolled *** the increase in cold compression deformation,the dislocation density increased and the microhardness increased gradually,and there is no obvious rule for the change of mean nano-hardness in micro-zone for the center of ***,the uniformity of nano-hardness in the micro-zone increased first and then decreased,and the value of residual stress has obvious corresponding relationship with the uniformity of micro-zone *** cold compression deformation with appropriate reduction rate can reduce residual stress and improve nano-hardness uniformity of the hot-rolled samples,but more deformation(such as reduction rateε=5.59%)makes residual stress increase and makes uniformity of nano-hardness deteriorate.

关键词： Ferrite Cold compression deformation Residual stress Nano-hardness Uniformity Dislocation density

Word-Pair Relevance Modeling with Multi-View Neural Attention Mechanism for Sentence Alignment

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Journal of Computer Science & Technology 2020年第3期35卷 617-628页

作者： Ying Ding Jun-hui Li Zheng-xian Gong Guo-Dong Zhou School of Computer Science and Technology Soochow UniversitySuzhou 215006China

Sentence alignment provides multi-lingual or cross-lingual natural language processing(NLP)applications with high-quality parallel sentence ***,an aligned sentence pair contains multiple aligned words,which intuitively play different roles during sentence *** by this intuition,we propose to deal with the problem of sentence alignment by exploring the semantic interactionship among fine-grained word pairs within the framework of neural *** particular,we first employ various relevance measures to capture various kinds of semantic interactions among word pairs by using a word-pair relevance network,and then model their importance by using a multi-view attention *** results on both monotonic and non-monotonic bitexts show that our proposed approach significantly improves the performance of sentence alignment.

关键词： sentence alignment neural network word-pair relevance network multi-view attention network

Crystalline-amorphous M@MN_x(M=Co,Fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： Yang Yang Xiao-Chuan Duan Shao-hui Guo xian-Ming Zhang College of Materials Science and Engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyYuci030600China

Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy ***,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MN_(x)(M=Co,Fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-NG)are synthesized by facile hydrothermal reaction and nitridation *** the nitriding process,metal ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystalline *** Co@CoN_(x)@NC-NG catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·L^(-1)H_(2)SO_4 and1.0 mol·L^(-1)KOH electrolytes,*** Co@CoN_(x)@NC-NG retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline *** outstanding HER performance originates from the crystalline-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER *** outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： Hydrogen evolution reaction Electrocatalysts Iron group metals Heterojunction Crystalline-amorphous structure

Quantum simulation of particle pair creation near the event horizon

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National Science Review 2020年第9期7卷 1476-1484页

作者： Yao Wang Chong Sheng Yong-Heng Lu Jun Gao Yi-Jun Chang Xiao-Ling Pang Tian-Huai Yang Shi-ning Zhu hui Liu xian-Min Jin Center for Integrated Quantum Information Technologies (IQIT) School of Physics and Astronomy and State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University National Laboratory of Solid State Microstructures and School of Physics Collaborative Innovation Center of Advanced MicrostructuresNanjing University CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics University of Science and Technology of China

Though it is still a big challenge to unify general relativity and quantum mechanics in modern physics, the theory of quantum field related with the gravitational effect has been well developed and some striking phenomena are predicted, such as Hawking radiation. However, the direct measurement of these quantum effects under general relativity is far beyond present experiment techniques. Fortunately, the emulation of general relativity phenomena in the laboratory has become accessible in recent years. However, up to now,these simulations are limited either in classical regime or in flat space whereas quantum simulation related with general relativity is rarely involved. Here we propose and experimentally demonstrate a quantum evolution of fermions in close proximity to an artificial black hole on a photonic chip. We successfully observe the acceleration behavior, quantum creation, and evolution of a fermion pair near the event horizon:a single-photon wave packet with positive energy escapes from the black hole while negative energy is captured. Our extensible platform not only provides a route to access quantum effects related with general relativity, but also has the potentiality to investigate quantum gravity in future.

关键词： quantum simulation general relativity transform optics particle pair creation black hole

Measurements of Wind Loads on Side-by-Side Semi-Submersibles in A Wind Tunnel

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China Ocean Engineering 2021年第4期35卷 531-543页

作者： DONG Qing GUO Xiao-xian YANG Jian-min LU Hai-ning HUANG Longwei State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University(SJTU)Shanghai 200240China SJTU Yazhou Bay Institute of Deepsea Technology Sanya 572000China

The multi-body system has been a popular form for offshore operations in terms of high *** wind effects are crucial which directly affect the relative positions of floating bodies and operating *** this study,the aerodynamic characteristics for two coupled semi-submersibles were analyzed in a wind tunnel to fill the gaps in literature related to the wind sheltering on offshore *** influences of separation distance were also *** to the results,substantial shielding effects were observed and wind forces on the shielded vessel decreased dramatically:a reduction in the transverse force could be up to 74%.Moreover,the longitudinal wind load was amplified by the platform abreast in a side-by-side *** expected,the interference level became more pronounced with a decreasing separation *** cases in which wind interaction decayed rapidly with distance,logarithmic functions were preferable for describing the relationship between *** linear fitting was reasonable for the transverse wind force when there was still evident sheltering at a quite large *** length of shielding area was another important factor that there was approximately a linear relationship between it and the shielding level for two platforms in close proximity at various wind attack *** on the two parameters,a preliminary wind loads estimation method considering shielding effects was *** approach can aid the industry to have a qualitative assessment of wind sheltering especially at early stages.

关键词： wind loads side-by-side shielding effect wind tunnel test

Numerical simulation of 3D electromagnetic–thermal phenomena in an induction heated slab

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Journal of Iron and Steel Research International 2020年第4期27卷 420-432页

作者： He-ping Liu xian-hui Wang Liang-ying Si Jian Gong Central Iron and Steel Research Institute Beijing 100081China Shougang Zhixin Qian’an Electromagnetic Material Co. Ltd.Qian’an 064404HebeiChina

A mathematical model was developed to get an insight into 3D electromagnetic–thermal phenomena in an induction heated steel slab with a large width/thickness ratio by solving a fully coupled Maxwell equations and energy conservation *** spatial heat radiation between the slab surface and the refractory wall in an induction furnace was *** electromagnetic induction and temperature distribution features inside the slab with time evolution were *** effects of electromagnetic induction parameters,thermal conductivity of the material and process parameters on the induction heating process were theoretically *** results show that the spatial distribution of induction heat generation inside the slab is *** high work frequency and the low heat conductivity of slab increase the non-uniformity of slab induction heating *** radiative heat loss and heat transfer between the slab and the metal parts used for holding the slab have an important effect on the slab surface *** is necessary to separately control the current input in the multi-layer coil windings along the height direction of furnace and adopt the multi-step heating strategies with time evolution to improve the homogenization of the slab temperature.

关键词： Slab Electromagnetic feld Induction heating Numerical simulation

Toward discovering low-lying P-wave excited∑_(c)baryon states

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Chinese Physics C 2022年第2期46卷 24-34页

作者： Kai-Lei Wang xian-hui Zhong Department of Electronic Information and Physics Changzhi UniversityChangzhi 046011China Department of Physics Hunan Normal Universityand Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of EducationChangsha 410081China Synergetic Innovation Center for Quantum Effects and Applications(SICQEA) Hunan Normal UniversityChangsha 410081China

In this study,by combining the equal spacing rule with recent observations of Ω_(C)(X)and Ξ_(C)(X)baryons,we predict the spectrum of the low-lying λ-mode 1P-wave excited ∑_(c) ***,their strong decay properties are predicted using the chiral quark model and the nature of∑_(c)(2800)is investigated by analyzing the invariant mass *** ∑_(c)(2800)structure observed in the Λ_(c)πmass spectrum was found to potentially arise from two overlapping P-wave resonances,∑_(c)(2813)3/2^(-)and ∑_(c)(2840)5/2^(-).These resonances have similar decay widths of Г〜40 MeV and predominantly decay into the Λ_(c)π *** ∑_(c)(2755)1/2^(-)state is likely to be a very narrow state with a width of Г〜15 MeV,with its decays almost saturated by the Λ_(c)π ***,evidence of the Lc(2755)1/2^(-)resonance as a very narrow peak may be seen in the Λ_(c)π invariant mass *** other two P-wave states,∑_(c)(2746)1/2^(-)and ∑_(c)(2796)3/2^(-),are relatively narrow states with similar widths of「〜30 MeV and predominantly decay into ∑_(c)π and ∑^(*)_(c)π,*** study can provide useful references for discovering these low-lying P-wave states in forthcoming experiments.

关键词： quark model strong decay ∑_(c)baryons

Effect of aluminum on secondary recrystallization texture and magnetic properties of grain-oriented silicon steel

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Journal of Iron and Steel Research International 2021年第4期28卷 479-487页

作者： Qian Gao xian-hui Wang Jun Li Jian Gong Bo Li Central Iron and Steel Research Institute Beijing 100081China Shougang Zhixin Qian'an Electromagnetic Material Co. Ltd.Qian'an 064404HebeiChina

The slab low-temperature reheating grain-oriented silicon steel was prepared in the laboratory,and the high-temperature annealing interruption tests were carried *** effects of aluminum(which meant acid-soluble aluminum)on the grain size texture,precipitate,magnetic properties and their correlations were *** results showed that with the increase in aluminum element,the grain size decreased,while the intensity of{114}and{111}textures increased in the primary recrystallization ***,the pinning force during the secondary recrystallization and the onset secondary recrystallization temperature were *** precipitates were concluded to have a more important role on determining the onset secondary recrystallization temperature than the primary grain *** higher onset temperature resulted in sharper Goss texture and the better magnetic properties,but when the aluminum content came up to a certain extent,a fine-grain structure was *** most suitable aluminum content for present study was 0.025 wt.%,while the onset secondary recrystallization temperature and the primary texture were considered to be conducive to the sharpness of Goss texture.

关键词： Grain-oriented silicon steel Aluminum Texture Secondary recrystallization Precipitate Magnetic property

Air combat decision-making of multiple UCAVs based on constraint strategy games

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Defence Technology（防务技术） 2022年第3期18卷 368-383页

作者： Shou-yi Li Mou Chen Yu-hui Wang Qing-xian Wu College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing211100China

Game theory can be applied to the air combat decision-making problem of multiple unmanned combat air vehicles(UCAVs).However,it is difficult to have satisfactory decision-making results completely relying on air combat situation information,because there is a lot of time-sensitive information in a complex air combat *** this paper,a constraint strategy game approach is developed to generate intelligent decision-making for multiple UCAVs in complex air combat environment with air combat situation information and time-sensitive ***,a constraint strategy game is employed to model attack-defense decision-making problem in complex air combat ***,an algorithm is proposed for solving the constraint strategy game based on linear programming and linear inequality(CSG-LL).Finally,an example is given to illustrate the effectiveness of the proposed approach.

关键词： Game theory Time-sensitive information Constraint strategy games Polytope strategy games Multiple UCAVs Air combat decision-making