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Journal of Materials Science & Technology 2021年第18期77卷 196-208页

作者： H.L.Wei f.q.liu L.Wei T.T.liu W.H.Liao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing.210094China State Key Laboratory of Solidification Processing Northwestern Poly technical UniversityXi'an710072China

Laser directed energy deposition(DED)involves complex physical processes,and the trial and error examinations are time consuming and cost *** research paradigm can be reshaped using advanced phenomenological models via computing the spatiotemporal variations of the build *** this work,multi-layer and multi-track laser DED of Ti-6 Al-4 V were systematically explored on multiple scales including the 1D track,the 2D layer and the 3D full build considering the complex transport of energy,mass,and momentum in the moving freeform molten *** results showed that convex,nearflat,and wavy builds were generated using gradually larger hatch *** profiles of individual tracks and layers were extracted through the unique advantages of the *** individual tracks exhibited various patterns and rotated with specific inclinations to form distinct layer *** net increments of the deposit generated upon the printing of a new track during the continuous deposition process showed that the smaller hatch spacing caused higher overlap rate of horizontally adjacent tracks but lower remelting rate of vertically adjacent tracks in neighboring *** 3D numerical model was validated with corresponding experiments for various process *** scientific findings can provide useful insights for further researches of DED.

关键词： Additive manufacturing Multi-layer and multi-track Numerical model Build features Molten pool

CT血管成像虚拟门静脉压力梯度(CHESS 1601):门静脉高压无创诊断的前瞻性多中心研究

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国际医学放射学杂志 2019年第2期42卷 237-237页

作者： X.L.qi W.M.An f.q.liu R.Z.qi L.Wang Y.N.liu. 胡芳(译) 杜明珊(校) Chinese Portal Hypertension Diagnosis and Monitoring Study Group(CHESS) CHESS Frontier CenterLanzhou UniversityLanzhouChina 不详

目的建立并验证一种基于CT血管成像的预估门静脉压力梯度的计算机模型,命名为虚拟门静脉压力梯度(HVPG),使肝硬化病人门静脉高压的无创诊断成为可能。材料与方法在这项前瞻性多中心诊断试验(Clinical ***标志符:NCT02842697)中,2016年8... 详细信息

目的建立并验证一种基于CT血管成像的预估门静脉压力梯度的计算机模型,命名为虚拟门静脉压力梯度(HVPG),使肝硬化病人门静脉高压的无创诊断成为可能。材料与方法在这项前瞻性多中心诊断试验(Clinical ***标志符:NCT02842697)中,2016年8月—2017年4月从3个大型肝病中心连续招募了102例符合条件的参与者(年龄21~75岁,平均47岁;包括男性68例,年龄21~73岁,平均44岁,女性34例,年龄24~75岁,平均52岁)。

关键词：无创诊断门静脉压力梯度门静脉高压血管成像 CT

The effects of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents:a meta-analysis

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Neural Regeneration Research 2025年第5期20卷 1513-1520页

作者： Xueyun Shao Longfei He Yangyang liu Physical Education School Shenzhen UniversityShenzhenGuangdong ProvinceChina Shenzhen Institute of Neuroscience ShenzhenGuangdong ProvinceChina

Brain-derived neurotrophic factor is a crucial neurotrophic factor that plays a significant role in brain health. Although the vast majority of meta-analyses have confirmed that exercise interventions can increase brain-derived neurotrophic factor levels in children and adolescents, the effects of specific types of exercise on brain-derived neurotrophic factor levels are still controversial. To address this issue, we used meta-analytic methods to quantitatively evaluate, analyze, and integrate relevant studies. Our goals were to formulate general conclusions regarding the use of exercise interventions, explore the physiological mechanisms by which exercise improves brain health and cognitive ability in children and adolescents, and provide a reliable foundation for follow-up research. We used the Pub Med, Web of Science, Science Direct, Springer, Wiley Online Library, Weipu, Wanfang, and China National Knowledge Infrastructure databases to search for randomized controlled trials examining the influences of exercise interventions on brain-derived neurotrophic factor levels in children and adolescents. The extracted data were analyzed using Review Manager 5.3. According to the inclusion criteria, we assessed randomized controlled trials in which the samples were mainly children and adolescents, and the outcome indicators were measured before and after the intervention. We excluded animal experiments, studies that lacked a control group, and those that did not report quantitative results. The mean difference(MD;before versus after intervention) was used to evaluate the effect of exercise on brain-derived neurotrophic factor levels in children and adolescents. Overall, 531 participants(60 children and 471 adolescents, 10.9–16.1 years) were included from 13 randomized controlled trials. Heterogeneity was evaluated using the q statistic and I^(2) test provided by Review Manager software. The meta-analysis showed that there was no heterogeneity among the studies(P = 0.67,

关键词： adolescents brain-derived neurotrophic factor children exercise meta-analysis randomized controlled trials

Offload Strategy for Edge Computing in Satellite Networks Based on Software Defined Network

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Computers, Materials & Continua 2025年第1期82卷 863-879页

作者： Zhiguo liu Yuqing Gui Lin Wang Yingru Jiang Communication and Network Laboratory Dalian UniversityDalian116622China College of Environment and Chemical Engineering Dalian UniversityDalian116622China

Satellite edge computing has garnered significant attention from researchers;however,processing a large volume of tasks within multi-node satellite networks still poses considerable *** sharp increase in user demand for latency-sensitive tasks has inevitably led to offloading bottlenecks and insufficient computational capacity on individual satellite edge servers,making it necessary to implement effective task offloading scheduling to enhance user *** this paper,we propose a priority-based task scheduling strategy based on a Software-Defined Network(SDN)framework for satellite-terrestrial integrated networks,which clarifies the execution order of tasks based on their ***,we apply a Dueling-Double Deep q-Network(DDqN)algorithm enhanced with prioritized experience replay to derive a computation offloading strategy,improving the experience replay mechanism within the Dueling-DDqN ***,we utilize the Deep Deterministic Policy Gradient(DDPG)algorithm to determine the optimal resource allocation strategy to reduce the processing latency of *** results demonstrate that the proposed d3-DDPG algorithm outperforms other approaches,effectively reducing task processing latency and thus improving user experience and system efficiency.

关键词： Satellite network edge computing task scheduling computing offloading

Anomalous quality factor evolution of induced transparency in a virtualized coupled-oscillator system

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 148-155页

作者： Yunhan Yang Han Jia Tuo liu Yuzhen Yang Jun Yang Key Laboratory of Noise and Vibration Research Institute of Acoustics Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

The phenomenon of induced transparency, characterized by a high quality(q) factor, holds significant importance in the fields of high-precision sensing, energy storage and wave manipulation. Conventional transparency systems are often constrained by the limited experimentally accessible parameter space and the lack of independent control over intrinsic parameters, thereby hindering advanced research on high-q effects. Here we propose a virtualized coupled-oscillator system that enables reconfigurable induced transparency in the reflection spectrum. By virtually incorporating a pair of coupled oscillators into an individual acoustic meta-atom, we achieve the manipulation of induced transparency in a decoupled, wide-ranging, and elaborate manner. Exploiting the diverse evolutions across the intrinsic parameter space, we show experimentally a counter-intuitive increase in the q-factor of the transparency window, which is attributed to the enhanced dissipation of the bright ***, a constant group delay at the center frequency is observed accompanying this evolution. Our work demonstrates an intriguing platform as well as a novel strategy to engineer high-q induced transparency phenomenon, and paves the way towards applications in programmable acoustic sensors, filters and slow-wave devices.

关键词： induced transparency acoustic meta-atom high quality-factor scattering programmable intrinsic parameter

GLOBAL SUPERCONVERGENCE ESTIMATES Of fINITE ELEMENT METHOD fOR SCHRODINGER EqUATION

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Journal of Computational Mathematics 1998年第6期16卷 521-526页

作者： Lin, q liu, Xq Acad Sinica Inst Syst Sci Beijing 100080 Peoples R China Xiangtan Teachers Coll Dept Math Hunan 411201 Peoples R China

In this paper, we shall study the initial boundary value problem of Schrodinger equation. The second order gradient superconvergence estimates for the problem are obtained solving by linear finite elements.

关键词： finite element superconvergence estimates interpolation Schrodinger equation

Rational design of chemically complex metallic glasses by hybrid modeling guided machine learning

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npj Computational Materials 2021年第1期7卷 1242-1251页

作者： Z.q.Zhou q.f.He X.D.liu q.Wang J.H.Luan C.T.liu Y.Yang Department of Mechanical Engineering College of EngineeringCity University of Hong KongKowloonHong KongChina College of Mechatronics and Control Engineering Shenzhen UniversityShenzhenChina Laboratory for Structures Institute of Materials ScienceShanghai UniversityShanghaiChina Department of Materials Science and Engineering College of EngineeringCity University of Hong KongKowloonHong KongChina Department of Advanced Design and System Engineering College of EngineeringCity University of Hong KongChina

The compositional design of metallic glasses(MGs)is a long-standing issue in materials science and ***,traditional experimental approaches based on empirical rules are time consuming with a low *** this work,we successfully developed a hybrid machine learning(ML)model to address this fundamental issue based on a database containing~5000 different compositions of metallic glasses(either bulk or ribbon)reported since *** the prior works relying on empirical parameters for featurization of data,we designed modeling guided data descriptors in line with the recent theoretical models on amorphization in chemically complex alloys for the development of the hybrid classification-regression ML *** hybrid ML modeling was validated both numerically and *** importantly,it enabled the discovery of MGs(either bulk or ribbon)through the ML-aided deep search of a multitude of quaternary to scenery alloy *** computational framework herein established is expected to accelerate the design of MG compositions and expand their applications by probing the complex and multi-dimensional compositional space that has never been explored before.

关键词： alloy glasses metallic

Precipitation on stacking faults in Mg–9.8wt%Sn alloy

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Journal of Materials Science & Technology 2020年第10期42卷 230-240页

作者： C.q.liu C.He H.W.Chen J.f.Nie International Joint Laboratory for Light Alloys(Ministry of Education) College of Materials Science and EngineeringChongqing UniversityChongqing400044China Department of Materials Science and Engineering Monash UniversityVictoria3800Australia Electron Microscopy Center Chongqing UniversityChongqing400044PR China

In this work,we have systematically investigated precipitation ofβ’-Mg3Sn phase on intrinsic stacking faults I1 and I2 in a Mg-9.8 wt%Sn alloy using aberration-corrected scanning transmission electron *** observed I1 faults are generated by the dissociation of c+a perfect dislocations and bounded by frank partial dislocations having a Shockley *** ofβ’on I1 involves a shear of 1/3α,similar to its formation directly from theα-Mg ***β’phase often nucleates at one end of an I1 fault due to the interaction between shear strain fields ofβ’and the Shockley component of the frank partial at that end,and subsequently grows towards the other end of the *** theβ’reaches to the other end,the Shockley partial bounding the lengthening end of theβ’reacts with the frank partial bounding the fault,generating an a perfect dislocation that can glide away from the precipitate and the *** observed I2 faults are generated by the dissociation of a perfect dislocations and bounded by Shockley *** ofβ’on I2 does not need a shear of 1/3α,since the pre-existing I2 fault already provides an ABCA four-layer structure ofβ’.Thickening of theβ’that has already formed on the I2 involves the successive occurrence of three crystallographically equivalent shears of 1/3αon every second(0002)αplane of theα-Mg *** this thickening mechanism is similar to that of theβ’formed directly from theα-Mg matrix,an a perfect dislocation will be produced when theβ’is thickened to eight layers,and it can again glide away from the precipitate and the fault.

关键词： Heterogeneous precipitation HAADf-STEM Shockley partial dislocation frank partial dislocation Dislocation reaction

Molecular Arrangement of a Bolaamphiphilic Anthrancene Derivative in Langmuir-Blodgett film

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Chinese Chemical Letters 2001年第12期12卷 1105-1108页

作者： Lu, q liu, MH Chinese Acad Sci Lab Colloid & Interface Sci Ctr Mol Sci Inst Chem Beijing 100080 Peoples R China

This paper reports the molecular assembly in the LB film of a novel bolaamphiphilic anthracene derivative (BISANS) in comparison with that of one-headed amphiphilic anthracene derivative (ANS). While ANS formed a stretched monolayer at the air/water interface, BISANS underwent aggregation to form crystal film on the water surface. Both of the H-aggregates and J-aggregates exist in the transferred LB films of bolaamphiphilic BISANS, only J-aggregates formed in the LB film of ANS.

关键词： bolaamphiphile air/water interface stretched monolayer

Designing metallic glasses with optimal combinations of glass-forming ability and mechanical properties

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Journal of Materials Science & Technology 2021年第8期67卷 254-264页

作者： S.J.Wu Z.q.liu R.T.qu Z.f.Zhang Laboratory of fatigue and fracture for Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

It is a long-standing challenge to search for metallic glasses(MGs)with optimal combinations of glassforming ability(GfA),strength and toughness in the vast compositional *** taking into account both recently developed ellipse criterion and temperature-based GfA criterion,here we established quantitative correlations among compositions,elastic constants,GfA and mechanical properties of MGs,which enable to predict the GfA,fracture strength and fracture surface simultaneously in advance once the compositions of MGs are *** data confirm the validity of this approach in ***,a strategy for designing MGs with optimal combinations of strength,toughness and GfA is proposed,which allows for high-throughput discovering glass formers with excellent mechanical properties.

关键词： Metallic glass Composition Elastic constant Mechanical property Glass-forming ability