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Growth mechanisms of interfacial carbides in solid-state reaction between single-crystal diamond and chromium

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Journal of Materials Science & Technology 2023年第13期144卷 138-149页

作者： Zhuo Liu wei cheng Dekui Mu Qiaoli Lin Xipeng Xu Han Huang Institute of Manufacturing Engineering Huaqiao UniversityXiamen 361021China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730000China School of Mechanical and Mining Engineering The University of QueenslandBrisbaneQLD 4072Australia

Interfacial bonding is one of the most challenging issues in the fabrication,and hence comprehensively influences the properties of diamond-based metal matrix composites(MMCs)*** this work,solid-state(S/S)interface reaction between single-crystal synthetic diamond and chromium(Cr)metal was critically examined with special attention given to unveil the role of crystal orientation in the for-mation and growth of interfacial *** has been revealed that catalytically converted carbon(CCC)was formed prior to chromium carbides,which is counterintuitive to previous *** 7 C 3 was the first carbide formed in the S/S interface reaction,aided by the relaxation of diamond lattices that re-duces the interfacial *** Cr 7 C 3 and Cr 3 C 2 carbides were formed at 600 and 800℃,respectively,with the growth preferred on diamond(100)plane,because of its higher density of surface defects than(111)*** strain distribution was quasi-quantitively measured using windowed Fourier Transform-Geometric Phase Analysis(WFT-GPA)analysis and an ameliorated strain concentration was found after the ripening of interfacial *** morphologies of Cr_(3)C_(2) grown on diamond(100)and(111)planes were perceived after S/S interface reaction at 1000℃,which is reported for the first *** underlying mechanisms of Cr-induced phase transformation on diamond surface,as well as the crystal orientation dependent growth of interfacial carbides were unveiled using the first-principles *** formation and growth mechanisms of Cr_(3)C_(2) were elucidated using SEM,TEM and XRD ***,an approach for tailoring the interfacial microstructure between synthetic diamond and bonding metals was proposed.

关键词： Solid-state Interface reaction Synthetic diamond Phase transformation Chromium carbide

Dynamics and rebound behavior analysis of flexible tethered satellite system in deployment and station-keeping phases

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Defence Technology（防务技术） 2022年第3期18卷 509-523页

作者： Yue Zhang Xin Jiang Zheng-feng Bai Jia-wen Guo cheng wei School of Space Science and Technology Xidian UniversityXi'an710126China School of Astronautics Harbin Institute of TechnologyHarbin150001China Department of Mechanical Engineering Harbin Institute of TechnologyWeihai264209China

The tether deployment of a tethered satellite system involves the consideration of complex dynamic properties of the tether,such as large deformation,slack,and even rebound,and therefore,the dynamic modelling of the tether is necessary for performing a dynamic analysis of the *** a variablelength tether element,the absolute nodal coordinate formulation(ANCF)in the framework of the arbitrary Lagrange-Euler(ALE)description was used to develop a precise dynamic model of a tethered *** model considered the gravitational gradient force and Coriolis force in the orbital coordinate frame,and it was validated through numerical *** the presence of dynamic constraints,a deployment velocity of the tether was obtained by an optimal *** the simulation,rebound behavior of the tethered satellite system was observed when the ANCF-ALE model was ***,the rebound behavior cannot be predicted by the traditional dumbbell ***,an improved optimal deployment velocity was *** results indicated that the rebound phenomenon was eliminated,and smooth deployment as well as a stable state of the station-keeping process were ***,the swing amplitude in the station-keeping phase decreased when a deployment strategy based on the improved optimal deployment velocity was used.

关键词： Tethered satellite system Dynamic model Rebound Deployment ANCF-ALE

Estimation of Gaussian overlapping nuclear pulse parameters based on a deep learning LSTM model

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Nuclear Science and Techniques 2019年第11期30卷 83-94页

作者： Xing-Ke Ma Hong-Quan Huang Qian-cheng Wang Jing Zhao Fei Yang Kai-Ming Jiang wei-cheng Ding wei Zhou College of Nuclear Technology and Automation Engineering Chengdu University of Technology

A long short-term memory(LSTM)neural network has excellent learning ability applicable to time series of nuclear pulse *** can accurately estimate parameters associated with amplitude,time,and so on,in digitally shaped nuclear pulse signals—especially signals from overlapping *** learning the mapping relationship between Gaussian overlapping pulses after digital shaping and exponential pulses before shaping,the shaping parameters of the overlapping exponential nuclear pulses can be estimated using the LSTM ***,the Gaussian overlapping nuclear pulse(ONP)parameters which need to be estimated received Gaussian digital shaping treatment,after superposition by multiple exponential nuclear ***,a dataset containing multiple samples was produced,each containing a sequence of sample values from Gaussian ONP,after digital shaping,and a set of shaping parameters from exponential pulses before digital ***,the Training Set in the dataset was used to train the LSTM *** these datasets,the values sampled from the Gaussian ONP were used as the input data for the LSTM model,and the pulse parameters estimated by the current LSTM model were calculated by forward ***,the loss function was used to calculate the loss value between the network-estimated pulse parameters and the actual pulse ***,a gradient-based optimization algorithm was applied,to feedback the loss value and the gradient of the loss function to the neural network,to update the weight of the LSTM model,thereby achieving the purpose of training the ***,the sampled value of the Gaussian ONP for which the shaping parameters needed to be estimated was used as the input data for the LSTM *** this,the LSTM model produced the required nuclear pulse parameter *** summary,experimental results showed that the proposed method overcame the defect of local convergence encountered in traditional methods and could accurately extract para

关键词： Nuclear pulses S–K digital shaping Deep learning LSTM

Corrosion monitoring system design for coating wire of steel in ocean

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 420-424页

作者： wei Shi-cheng XU Bin-shi WANG Hai-dou CHEN Jian-she wei Xu-jun National Key Laboratory for Remanufacturing ArmoredEngineering Institute Beijing 100072 China National Key Laboratory for Remanufacturing ArmoredEngineering Institute Beijing 100072 China National Key Laboratory for Remanufacturing ArmoredEngineering Institute Beijing 100072 China School of Materials Science and Engineer Northeastern University Shenyang 110004 China School of Materials Science and Engineer Northeastern University Shenyang 110004 China

The monitoring system design used in anti-corrosion of coating wire of steel in ocean were concerned. A corrosion monitoring system adapting to corrosion observation of coating wire of steel was introduced in details, including design and choice of software and hardware. This system will play an important role in the collection, procession, demonstration, deposition and accident alarm of corrosion data of oceanic coating wire of steel.

关键词： ocean coating wire of steel corrosion monitor

Testing the consistency of propagation between light and heavy cosmic ray nuclei

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Chinese Physics C 2022年第9期46卷 257-267页

作者： Yu Wang Juan Wu wei-cheng Long School of Mathematics and Physics China University of GeosciencesWuhan 430074China

One of the fundamental challenges in cosmic ray physics is to explain the nature of cosmic ray acceleration and propagation *** to the precise cosmic ray data measured by recent space experiments,we can investigate cosmic ray acceleration and propagation models more comprehensively and *** this paper,we combine the secondary-to-primary ratios and primary spectra measured by PAMELA,AMS02,ACE-CRIS,and Voyager-1 to constrain the cosmic ray source and transport *** study shows that the Z>2 data yield a medium-energy diffusion slope δ_(2)~(0.42,0.48)and a high-energy slope δ_(3)~(0.22,0.34).The Z≤2 species place a looser constraint on δ_(2)~(0.38,0.47)but a tighter constraint onδ3~(0.21,0.30).The overlaps imply that heavy and light particles can provide compatible results at medium to high ***,both the light and heavy nuclei indicate a consistent diffusion slope variation ΔδH at 200~300 *** low energies,significant disagreements exist between heavy and light *** boron-to-carbon ratio requires a much larger diffusion slope shift ΔδL at approximately 4 GV or a stronger Alfvén velocity vA than the low-mass *** indicates that the heavy and light particles may suffer different low-energy transport behaviors in the ***,a better understanding of the consistency/inconsistency between the heavy and light cosmic rays relies on more precise cross-sections,better constraints on correlations in systematic errors of data,a more accurate estimation of the galaxy halo size,and a more robust description of solar modulation during the reversal period of the heliospheric magnetic field.

关键词： cosmic ray propagation acceleration

Hydroelastic Analysis of a Flexible Floating Body for the Variation of Incident Wave

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中国造船 2007年第B11期48卷 362-368页

作者： WANG Cong CUI wei-cheng Offshore Oil Engineering Co. Ltd. Tianjin 300451 China China Ship Scientific ReSearch Center Wuxi Jiangsu 214082 China

Effects of RE^(3+)(RE=La,Ce,Pr,Sm,Dy,Ho,Er,and Tm) on the luminescence of Sr_2MgSiO_5:Eu^(2+) phosphors

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Rare Metals 2011年第1期30卷 14-17页

作者： cheng Guang wei Xiaoyan cheng Liqun LIU Quansheng WANG Xiaochun SUN Haiying ZHANG Xiyan QIU Guanming School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China

Sr2MgSiO5：Eu^2＋phosphors were synthesized through a high temperature solid state reaction *** phase and luminescence properties of the samples were characterized by X-ray diffraction（XRD） and a luminescence *** effects of RE^3＋（RE = La,Ce,Pr,Sm,Dy,Ho,Er,and Tm） on the luminescent properties of the samples were *** results show that the luminescence spectrum of Sr2MgSiO5：Eu^2＋ is a broad band composed of two emission peaks,at 460 and at 530 nm under near-ultraviolet *** earth ions Re^3＋（RE = La,Ce,Pr,Sm,Dy,Ho,Er,and Tm） have great influence on the emission of Sr2MgSiO5：Eu^2＋ *** La^3＋ ion in Sr2MgSiO5：Eu^2＋ phosphors greatly enhances the emission at 460 and 530 nm.

关键词： phosphors solid state reactions rare earths luminescence

Altered amplitude of low-frequency fluctuations and default mode network connectivity in high myopia:a resting-state fMRI study

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International Journal of Ophthalmology(English edition) 2020年第10期13卷 1629-1636页

作者： Xue-wei Zhang Rong-Ping Dai Gang-wei cheng wei-Hong Zhang Qin Long Department of Radiology Translational Medical CenterPeking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Department of Interventional Radiology Emergency General HospitalBeijing 100028China Department of Ophthalmology Translational Medical CenterPeking Union Medical College HospitalKey Laboratory of Ocular Fundus DiseasesChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

AIM:To analyze changes in amplitude of low-frequency fluctuations(ALFFs)and default mode network(DMN)connectivity in the brain,using resting-state functional magnetic resonance imaging(rs-fMRI),in high myopia(HM)***:Eleven patients with HM(HM group)and 15 age-and sex-matched non-HM controls(non-HM group)were *** were calculated and compared between HM group and non-HM *** component analysis(ICA)was conducted to identify DMN,and comparisons between DMNs of two groups were ***-of-interest(ROI)-based analysis was performed to explore functional connectivity(FC)between DMN ***:Significantly increased ALFFs in left inferior temporal gyrus(ITG),bilateral rectus gyrus(REC),bilateral middle temporal gyrus(MTG),left superior temporal gyrus(STG),and left angular gyrus(ANG)were detected in HM group compared with non-HM group(all P<0.01).HM group showed increased FC in the posterior cingulate gyrus(PCC)/precuneus(preCUN)and decreased FC in the left medial prefrontal cortex(mPFG)within DMN compared with nonHM group(all P<0.01).Compared with non-HM group,HM group showed higher FC between mPFG and bilateral middle frontal gyrus(MFG),ANG,and MTG(all P<0.01).In addition,HM patients showed higher FC between PCC/(preCUN)and the right cerebellum,superior frontal gyrus(SFG),left pre CUN,superior frontal gyrus(SFG),and medial orbital of the superior frontal gyrus(ORB supmed;all P<0.01).CONCLUSION:HM patients show different ALFFs and DMNs compared with non-HM subjects,which may imply the cognitive alterations related to HM.

关键词： functional magnetic resonance imaging high myopia default mode network amplitude of lowfrequency fluctuation

Hot Deformation Behavior of Vanadium-microalloyed Medium-carbon Steel for Fracture Splitting Connecting Rod

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Journal of Iron and Steel Research International 2015年第7期22卷 615-621页

作者： wei-jun HUI Si-lian CHEN cheng-wei SHAO Yong-jian ZHANG Han DONG School of Mechanical Electronic and Control EngineeringBeijing Jiaotong University Central Iron and Steel Research Institute

Single compression tests were carried out with a Gleeble-3800 thermal simulator to investigate hot deform- ation behavior of two vanadium-microalloyed medium-carbon steels for fracture splitting connecting rod. The tests were performed to a total true strain of 0.92 at true strain rates ranging from 10-2 to 10 s-1 and deformation temper- ature of 900--1 150 ℃, The results show that hot deformation behavior of the tested steels is similar to that of con- ventional medium-carbon microalloyed steels and dynamic recrystallization is easier to occur at higher deformation temperature and lower strain rate. The austenite deformation resistance and activation energy of deformation increase with increasing vanadium content from 0.15% to 0. 28% and thus the starting time of dynamic recrystallization was delayed. Finer recrystallized austenite grain could he obtained at higher strain rate, lower deformation temperature and higher vanadium content. TEM observation of the specimens quenched just before and after deformation reveals that vanadium is mainly in dissolved solute condition in austenite and thus affects the dynamic recrystallization behavior of the tested steels mainly through solute-drag effect.

关键词： vanadium microalloyed medium-carbon steel hot deformation dynamic recrystallization fracture splitting connected rod