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Near-perfect replication on amorphous alloys through active force modulation based on machine learning/neural network parameter prediction

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 181-191页

作者： Senkuan Meng Zheng wang Ruisong Zhu Ruijie Liu Jiang Ma Lina Hu weihua wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong University College of Mechatronics and Control Engineering Shenzhen University Songshan Lake Materials Laboratory Institute of Physics Chinese Academy of Sciences

As a microforming technique, micro/nano-structural replication possesses advantages of high precision and efficiency. With the remarkable superplasticity in the supercooled liquid region, amorphous alloys or metallic glasses(MGs) are regarded as ideal materials for miniature fabrication. However, due to the intrinsic metastable nature of supercooled liquids, the design of imprinting processes for MGs poses a challenge. In the past, process parameters have largely relied on trial-and-error *** this work, a low-frequency active force modulation system is employed to apply a stable, precise, and real-time feedback stress field for imprinting of MG samples. Low-frequency vibrations can facilitate the filling of microstructures on the template surface by reducing the effective viscosity of the supercooled liquid. With the dataset composed of orthogonal experiments, a machine learning strategy based on back-propagation(BP) neural networks was utilized to construct a 3D parameter space for temperature, stress, and time, and to predict the corresponding filling ratio. Furthermore, the optimal combination of imprinting process parameters was identified, and its filling ratio was experimentally validated to reach as high as 0.94. The near-perfect replication of microstructures confirms the superiority of the active force modulation system and the data-driven strategy of machine learning-assisted parameter design. At the same time, this one-step microforming process provides a new approach to addressing the accuracy-cost trade-off dilemma in precision manufacturing.

关键词： metallic glass amorphous alloy microforming imprinting machine learning

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Metallic glassy fibers

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Science China(Physics,Mechanics & Astronomy) 2013年第12期56卷 2293-2301页

作者： wang weihua Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of Sciences

A review on the formation and unique physical and mechanical properties of metallic glassy fibers(MGFs)with the diameter ranging from micro to nano scales fabricated by a supercooled liquid extraction method(SLEM)is *** SLEM method,through driving metallic glass rods in their supercooled liquid region via superplasticity,can fabricate MGFs with precisely designed and controlled size and properties,high structural uniformity and surface smoothness and extreme *** SLEM method is efficient and the MGFs can be continuously prepared by this method.A parameter f based on the thermal and rheological properties of MG-forming alloys is proposed to control the preparation and size of the *** show that the novel MGFs with superior properties may attract intensive scientific interests and propel more engineering and functional applications.

关键词： metallic glassy fibers features forming ability properties

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A new room temperature viscoelastic inorganic glass

Materials Futures

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Materials Futures 2023年第4期2卷 151-152页

作者： weihua wang Songshan Lake Materials Laboratory DongguanGuangdong 523808People’s Republic of China Institute of Physics Chinese Academy of SciencesBeijing 100190People’s Republic of China

Inorganic glass is a non-crystalline material that lacks of a regular,periodic atomic or molecular structure,and are considered as frozen liquids because of the similarity between their static amorphous *** atoms and molecules in the glass can gradually rearrange and realign with time,giving rise to deformation or aging in most glass ***,viscoelastic behavior could not be readily observable at room temperature(RT)due to its long time *** paper introduce and comment a recent work published in Nature Energy,which discover a new class of viscoelastic inorganic glass with Tg well below *** VIGLAS is simply synthesized through adding high content of oxygen into tetrachloroaluminates to replace *** VIGLAS exhibits characteristics similar to both inorganic ceramics and organic polymers,which are particularly relevant in the realm of battery electrolytes where a balance between ionic conductivity and chemo-mechanical compatibility is crucial.

关键词： room temperature inorganic glass solid-state electrolytes

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A Learning Method for Pedestrian Activity Classification

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Chinese Journal of Electronics 2014年第1期23卷 129-134页

作者： wang weihua LIU Zhijing School of Computer Science and Technology Xidian University

Analysis of human activity and online anomaly detection from video sequences is one of the hottest and difficult research areas in computer *** paper describes a method for pedestrian gait classification in video sequence and deals with the classification of human gait types based on the notion that gait types can be analyzed into a series of consecutive postures types. First,silhouettes are extracted using the Background subtraction method which is combined with the time-stepping *** a method using recursion method for establishment of the standard gait state sequence is proposed. Meanwhile, wavelet moment method is used to extract features of the human body image, and the result matrix leads to Discrete hidden Markov models. Finally, Discrete hidden Markov models is used for human posture training, modeling and activity matching to recognize the human *** experiment tests show some encouraging results also indicates the algorithm has very small leak-examining and mistake-examining-rate, also shows the capability of realtime performance, which indicate that the method could be a choice for solving the problem but more tests are required.

关键词： Pedestrian gait classification Anomaly detection Wavelet moment Discrete hidden Markov models Standard gait state sequence

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Coupled thermal-mechanical analysis of two ITER-like first wall mockups under heat shock of plasma disruptions

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Science China(Technological Sciences) 2016年第3期59卷 476-487页

作者： HUANG ShengHong ZHAO YongQiang wang weihua School of Engineering Science University of Science and Technology of China Institute of Applied Physics of Army Office Academic

The first wall of the fusion reactor is a plasma-facing component and is a key link to maintain the integrity of structure during thermal shock induced by plasma disruptions. Be and W/Cu functionally graded materials are two kinds of important plas- ma-facing materials （PFM） of first wall in fusion reactor currently. Previous researches seldom comparatively evaluated the normal servicing and heat shock resistance performance of first walls with those two kinds of PFMs. And also there lacks cou- pled thermal/mechanical analysis on the heat shock process in consideration of multiple thermal/mechanical phenomena, such as material melting, solidification, evaporation, etc., which is significant to further understand the heat shock damage mecha- nism of the first wall with different PFMs. With the aim of learning more detailed mechanical mechanism of thermal shock damage and then improving the thermal shock resistance performance of different first wall designs, the coupled ther- mal/mechanical response of two typical ITER-like first walls with PFM of Be and functionally graded W-Cu respectively un- der the heat shock of 1 2 GW/m2 are computed by the finite element method. Special considerations of elastic-plastic defor- mation, material melting, and solidification are included in numerical models and methods. The mechanical response behaviors of different structures and materials under the normal servicing operation as well as plasma disruption conditions are analyzed and investigated comparatively. The results reveal that heat is mainly deposited on the PFM layer in thc high energy shock pulse induced by plasma disruptions, resulting in complex thermal stress change as well as mechanical itTeversible damage of thermal elastic and plastic expansion, contraction and yielding. Compared with the first wall with Be PFM, which mitigates the damages from heat shock at most only in the PFM layer with cost of whole PFM layer plastic yielding, the first wall with graded W-Cu PFM

关键词： first wall plasma facing component plasma disruptions thermal shock resistance finite element method

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Effects of tube system and data correction for fluctuating pressure test in wind tunnel

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Chinese Journal of Aeronautics 2018年第4期31卷 710-718页

作者： Xue wang Xunnian wang Xiaobo REN Xiwei YIN weihua wang State Key Laboratory of Aerodynamics China Aerodynamics Research and Development Center Low Speed Aerodynamics Institute China Aerodynamics Research and Development Center

The accuracy of fluctuating pressure test in wind tunnel is affected by the tube system. By employing contradistinctive experimental method, systematic study was conducted to investigate the effects of the tube system on fluctuating pressure. The analyzed tube system parameters include tube length, inside diameter, curvature, deflection angle, thickness, material, restrictor length,restrictor inside diameter, and restrictor place. It is found that all the tube system parameters mentioned above except tube curvature have non-negligible effects on fluctuating pressure. Based on the research results, test methods were presented for the fluctuating pressure measurement in low-speed wind tunnel, which can obviously improve the data accuracy but not lose test efficiency. The effectiveness of the method is verified by the wind tunnel test.

关键词： Data correction Fluctuating pressure Frequency response function Tube system Wind tunnel test

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Factors determining soil water heterogeneity on the Chinese Loess Plateau as based on an empirical mode decomposition method

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Journal of Arid Land 2020年第3期12卷 462-472页

作者： GONG Yidan XING Xuguang wang weihua Faculty of Agriculture and Food Kunming University of Science and TechnologyKunming 650500China Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education Northwest A&F UniversityYangling 712100China

Soil water is a critical resource,and as such is the focus of considerable physical *** of the distribution and spatial variability of soil water content(SWC)offers important agronomic and environmental *** of non-stationary and non-linear SWC distribution at different scales is a research *** on this context,we performed a case study on the Chinese Loess Plateau,with objectives of investigating spatial variability of SWC and soil properties(i.e.,soil particle composition,organic matter and bulk density),and determining multi-scale correlations between SWC and soil properties.A total of 86 in situ sampling sites were selected and 516 soil samples(0–60 cm depth with an interval of 10 cm)were collected in May and June of 2019 along the Yangling-Wugong-Qianxian transect,with a length of 25.5 km,in a typical wheat-corn rotation region of the Chinese Loess *** statistics and empirical mode decomposition(EMD)method were applied to evaluate characteristics of the overall and scale-specific spatial variation of SWC,and to explore scale-specific correlations between SWC and soil *** showed that the spatial variability of SWC along the Yangling-Wugong-Qianxian transect was medium to weak,with a variability coefficient range of 0.06–0.18,and it was gradually decreased as scale *** categorized the overall SWC for each soil layer under an intrinsic mode function(IMF)number based on the scale of occurrence,and found that the component IMF1 exhibited the largest contribution rates of 36.45%–56.70%.Additionally,by using EMD method,we categorized the general variation of SWC under different numbers of IMFs according to occurrence scale,and the results showed that the calculated scales among SWC for each soil layer increased in correspondence with higher IMF *** 78.00%of the total variance of SWC was extracted in IMF1 and ***,soil texture was the dominant control on

关键词： bulk density loess plateau soil water soil organic matter soil texture spatial variability

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Effects of water and salt coordinated regulation at the different growth stages on water consumption and yield of tomato

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International Journal of Agricultural and Biological Engineering 2021年第4期14卷 96-105页

作者： weihua wang Yidan Gong Faculty of Agriculture and Food Kunming University of Science and TechnologyKunming 650500China

The objective of this study was to explore the effects of different degrees of water and salt stress on the actual water consumption and soil salt accumulation of tomatoes and the salt tolerance characteristics of tomatoes under brackish water combined with regulated deficit irrigation *** greenhouse pot experiment was used to set three influencing factors,the irrigation water salinity S1 was 1.1 g/L(local shallow groundwater),S2 was 2.0 g/L,and S3 was 4.0 g/L,respectively,and different degrees of water deficit(W1 ranged from 65%-75%Field Capacity(FC),W2 ranged from 55%-65%FC,W3 ranged from 45%-55%FC)and seedling stage(T1),blossoming and bearing fruits stage(T2)and mature picking stage(T3).The response of fresh fruit weight,stems and leaves weight,yield and water use efficiency of tomato under water and salt stress were monitored and *** results showed the coordinated regulation of water and salt can significantly reduce the electrical conductivity of the 0-30 cm soil of the tomato root *** higher the salinity of irrigation water,the better the salt control effects of the coordinated regulation of water and salt;the coordinated regulation of water and salt at different growth stages had significant effects on the weight of fresh tomato fruits,the weight of stems and leaves and the *** salinity of irrigation water was in inverse proportion to the yield of tomatoes;In S1 treatment irrigation(irrigation water salinity was 1.1 g/L)under the mildly regulated deficit in the seedling stage(irrigation water was 55%-65%of the field water capacity)can effectively reduce the irrigation water volume during the whole growth stage while ensuring that there was no significant reduction in *** research results provided a scientific and reliable theoretical basis for the increase of local tomato production,the improvement of water use efficiency and the formulation of suitable irrigation patterns.

关键词： tomato coordinated regulation of water and salt soil electrical conductivity water consumption yield

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A New Load Balancing Scheme on Heterogeneous Database Cluster

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Geo-Spatial Information Science 2006年第3期9卷 216-222页

作者： GONG weihua wang Yuanzhen College of Computer Science and Technology Huazhong University of Science and Technology Guanshan Wuhan 430074 China.

In heterogeneous database cluster, the performance of load balancing is closely related to the computing capabilities of heterogeneous nodes and the different types of workloads. Thus, a method is introduced to evaluate the load status of nodes by the weighted load values with consideration of both the utilization of different resources and the workload types in a load balaneer and an efficient and dynamic load balancing scheme is proposed for OLTP（online transaction processing） workloads to maximize the utilization of distributed resources and achieve better performance, which need not collect the feedback of load information from the lower nodes and effectively keeps from the data skew. The simulation results for OLTP services gained by TPC-C tool show that the dynamic weighted balancing policy leads to sub-linear throughput speedup and keeps the heterogeneous cluster well balanced.

关键词： heterogeneous cluster OLTP load balancing

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The Nanoscale Density Gradient as a Structural Stabilizer for Glass Formation

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Engineering 2023年第10期29卷 120-129页

作者： Shaoxiong Zhou Bangshao Dong Yanguo wang Jingyu Qin weihua wang China Iron and Steel Research Institute Group Beijing 100081China Institute of Advanced Materials North China Electric Power UniversityBeijing 102206China Jiangsu JITRI Advanced Energy and Materials Research Institute Changzhou 213032China Beijing National Laboratory of Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China

The rapid cooling of a metallic liquid(ML)results in short-range order(SRO)among the atomic arrangements and a disordered structure in the resulting metallic glass(MG).These phenomena cause various possible features in the microscopic structure of the MG,presenting a puzzle about the nature of the MGs’microscopic structure beyond *** this study,the nanoscale density gradient(NDG)originating from a sequential arrangement of clusters with different atomic packing densities(APDs),representing the medium-range structural heterogeneity in Zr_(60)Cu_(30)Al_(10)MG,was characterized using electron tomography(ET)combined with image simulations based on structure *** coarse polyhedrons with distinct facets identified in the three-dimensional images coincide with icosahedron-like clusters and represent the spatial positions of clusters with high *** of the different clusters according to descending APD order in the glass-forming process are responsible for the NDG that stabilizes both the supercooled ML and the amorphous states and acts as a hidden rule in the transition from ML to MG.

关键词： Rapid cooling Amorphous solid Density gradient Electron tomography Atomic clusters

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