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Tunable polarization-drived superior energy storage performance in PbZrO_(3) thin films

Journal of Advanced Ceramics 2023年第5期12卷 930-942页

作者： Tiandong Zhang Zhuangzhuang Shi Chao Yin Changhai Zhang Yue Zhang Yongquan Zhang Qingguo Chen Qingguo Chi Key Laboratory of Engineering Dielectrics and Its Application Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 305-701Republic of Korea

Antiferroelectric PbZrO_(3)(AFE PZO)films have great potential to be used as the energy storage dielectrics due to the unique electric field(E)-induced phase transition ***,the phase transition process always accompanies a polarization(P)hysteresis effect that induces the large energy loss(Wloss)and lowers the breakdown strength(EBDS),leading to the inferior energy storage density(Wrec)as well as low *** this work,the synergistic strategies by doping smaller ions of Li^(+)–Al^(3+)to substitute Pb2+and lowering the annealing temperature(T)from 700 to 550℃are proposed to change the microstructures and tune the polarization characters of PZO films,except to dramatically improve the energy storage *** prepared Pb_((1−x))(Li_(0.5)Al_(0.5))_(x)ZrO_(3)(P_((1−x))(L_(0.5)A_(0.5))_(x)ZO)films exhibit ferroelectric(FE)-like rather than AFE character once the doping content of Li^(+)–Al^(3+)ions reaches 6 mol%,accompanying a significant improvement of W_(rec) of 49.09 J/cm^(3),but the energy storage efficiency(η)is only 47.94%due to the long-correlation of FE ***,the low-temperature annealing is carried out to reduce the crystalline degree and the P loss.P_(0.94)(L_(0.5)A_(0.5))_(0.06)ZO films annealed at 550℃deliver a linear-like polarization behavior rather than FE-like behavior annealed at 700℃,and the lowered remanent polarization(P_(r))as well as improved E_(BDS)(4814 kV/cm)results in the superior Wrec of 58.7 J/cm^(3) and efficiency of 79.16%,simultaneously possessing excellent frequency and temperature stability and good electric fatigue tolerance.

关键词： lead zirconate ionic pair polarization breakdown strength energy storage

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OCRBench: on the hidden mystery of OCR in large multimodal models

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science China(Information sciences) 2024年第12期67卷 23-35页

作者： Yuliang LIU Zhang LI Mingxin HUANG Biao YANG Wenwen YU Chunyuan LI Xu-Cheng YIN Cheng-Lin LIU Lianwen JIN Xiang BAI School of Artificial Intelligence and Automation Huazhong University of Science and Technology School of Electronic and Information Engineering South China University of Technology Microsoft Research School of Computer & Communication Engineering University of Science and Technology Beijing Institute of Automation Chinese Academy of Sciences School of Software Engineering Huazhong University of Science and Technology

Large models have recently played a dominant role in natural language processing and multimodal vision-language learning. However, their effectiveness in text-related visual tasks remains relatively unexplored. In this paper, we conducted a comprehensive evaluation of large multimodal models, such as GPT4V and Gemini, in various text-related visual tasks including text recognition, scene text-centric visual question answering(VQA), document-oriented VQA, key information extraction(KIE), and handwritten mathematical expression recognition(HMER). To facilitate the assessment of optical character recognition(OCR) capabilities in large multimodal models, we propose OCRBench, a comprehensive evaluation benchmark. OCRBench contains 29 datasets, making it the most comprehensive OCR evaluation benchmark available. Furthermore, our study reveals both the strengths and weaknesses of these models, particularly in handling multilingual text, handwritten text, non-semantic text, and mathematical expression *** importantly, the baseline results presented in this study could provide a foundational framework for the conception and assessment of innovative strategies targeted at enhancing zero-shot multimodal *** evaluation pipeline and benchmark are available at https://***/Yuliang-Liu/Multimodal OCR.

关键词： large multimodal model OCR text recognition scene text-centric VQA document-oriented VQA key information extraction handwritten mathematical expression recognition

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A deep learning-based model for automated STN localization using local field potentials in Parkinson’s disease

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Soft Computing 2025年第4期29卷 2343-2362页

作者： Hosny, Mohamed Naeem, Mohamed A. Zhu, Minwei Gao, Wenpeng Elshenhab, Ahmed M. Fu, Yili Department of Electrical Engineering Benha Faculty of Engineering Benha University Benha Egypt State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin150080 China Department of Mechatronics and Robotics Engineering Faculty of Engineering South Valley University Qena Egypt First Affiliated Hospital Harbin Medical University Harbin150001 China School of Life Science and Technology Harbin Institute of Technology Harbin150080 China Department of Mathematics Faculty of Science Mansoura University Mansoura35516 Egypt

Accurate identification of the subthalamic nucleus (STN) borders is time-consuming, relying heavily on the neurosurgeon expertise in manually interpreting the electrophysiological signals. Local field potentials (LFPs) have garnered imperative attention due to their strong correlation with the STN. However, existing detection models often face challenges with high computational complexity, hyperparameter optimization and lack of explainability, making them unreliable for clinicians. Therefore, this study introduces an explanatory framework using convolutional neural networks (CNN) for detecting the STN region from LFPs. Continuous wavelet transform is employed to convert LFPs signals into scalogram images, which are then processed by sixteen CNN models. We evaluated our framework by examining the impact of various limiting factors on the classification performance, including model size, learning rate (LR), optimizers and data scaling. Deep features are extracted from the top-performing CNN architectures to capture rich representations of the scalograms. These features are then fused and classified using k-nearest neighbour algorithm. Gradient-weighted class activation mapping is used to explain the decisions made by the proposed model. Our approach achieved an accuracy of 99.61%, outperforming individual CNN models for STN localization. The experimental results revealed that CNN models, embedded with additional hyperparameters and layers, generally outperformed smaller models. Besides, low LR significantly enhanced the performance compared to high LR. Moreover, features extracted from untuned networks produced lower performance than tuned networks. The proposed system could revolutionize deep brain stimulation surgery by increasing efficiency and reducing reliance on clinician expertise for STN detection. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Wavelet transforms

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Deformation behavior of Mg-Y-Ni alloys containing different volume fraction of LPSO phase during tension and compression through in-situ synchrotron diffraction

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Journal of Magnesium and Alloys 2024年第9期12卷 3631-3645页

作者： S.Z.Wu Y.Q.Chi G.Garces X.H.Zhou H.G.Brokmeier X.G.Qiao M.Y.Zheng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China Department of Physical Metallurgy CENIM-CSICAvenida Gregorio del Amo 828040 MadridSpain Institute of Materials Science and Engineering Clausthal University of TechnologyAgricolastrasse 6D-38678 Clausthal-ZellerfeldGermany

The deformation behavior of the as-extruded Mg-Y-Ni alloys with different volume fraction of long period stacking ordered(LPSO)phase during tension and compression was investigated by in-situ synchrotron *** micro-yielding,macro-yielding,tension-compression asymmetry and strain hardening behavior of the alloys were explored by combining with deformation *** micro-yielding is dominated by basal slip of dynamic recrystallized(DRXed)grains in tension,while it is dominated by extension twinning of non-dynamic recrystallized(non-DRXed)grains in *** macro-yielding,the non-DRXed grains are still elastic deformed in tension and the basal slip of DRXed grains in compression are ***,the LPSO phase still retains elastic deformation,but can bear more load,so the higher the volume fraction of hard LPSO phase,the higher the tensile/compressive macro-yield strength of the *** from the low volume fraction of the non-DRXed grains and the delay effect of LPSO andγphases on extension twinning,the as-extruded alloys exhibit excellent tension-compression *** the volume fraction of LPSO phase reaches∼50%,tension-compression asymmetry is reversed,which is due to the fact that the LPSO phase is stronger in compression than in *** tensile strain hardening behavior is dominated by dislocation slip,while the dominate mechanism for compressive strain hardening changes from twinning in theα-Mg grains to kinking of the LPSO phase with increasing volume fraction of LPSO *** activation of kinking leads to the constant compressive strain hardening rate of∼2500 MPa,which is significantly higher than the tensile strain hardening rate.

关键词： Mg-Y-Ni alloys LPSO phase In-situ synchrotron diffraction Micro-yielding Tensile-compression asymmetry Strain hardening

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Conventional and micro scale finite element modeling for metal cutting process:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 199-232页

作者： Le WANG Caixu YUE Xianli LIU Ming LI Yongshi XU Steven Y.LIANG Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

The metal cutting process is accompanied by complex stress field,strain field,temperature *** comprehensive effects of process parameters on chip morphology,cutting force,tool wear and residual stress are complex and *** element method(FEM)is considered as an effective method to predict process variables and reveal microscopic physical phenomena in the cutting ***,the finite element(FE)simulation is used to research the conventional and micro scale cutting process,and the differences in the establishment of process variable FE simulation models are distinguished,thereby improving the accuracy of FE *** reliability and effectiveness of FE simulation model largely depend on the accuracy of the simulation method,constitutive model,friction model,damage model in describing mesh element,the dynamic mechanical behavior of materials,the tool-chip-workpiece contact process and the chip formation *** this paper,the FE models of conventional and micro process variables are comprehensively and up-to-date reviewed for different materials and machining *** purpose is to establish a FE model that is more in line with the real cutting conditions,and to provide the possibility for optimizing the cutting process *** development direction of FE simulation of metal cutting process is discussed,which provides guidance for future cutting process modeling.

关键词： Conventional and micro scale Finite element simulation Metal cutting process Micro cutting Modeling

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RoMe: Towards Large Scale Road Surface Reconstruction Via Mesh Representation

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年第7期9卷 1-13页

作者： Mei, Ruohong Sui, Wei Zhang, Jiaxin Qin, Xue Wang, Gang Peng, Tao Chen, Tao Yang, Cong BeeLab School of Future Science and Engineering Soochow University Suzhou China Harbin Institute of Technology Harbin China Shandong University Shandong China

In autonomous driving applications, accurate and efficient road surface reconstruction is paramount. This paper introduces RoMe, a novel framework designed for the robust reconstruction of large-scale road surfaces. Leveraging a unique mesh representation, RoMe ensures that the reconstructed road surfaces are accurate and seamlessly aligned with semantics. To address challenges in computational efficiency, we propose a waypoint sampling strategy, enabling RoMe to reconstruct vast environments by focusing on sub-areas and subsequently merging them. Furthermore, we incorporate an extrinsic optimization module to enhance the robustness against inaccuracies in extrinsic calibration. Our extensive evaluations of both public datasets and wild data underscore RoMe's superiority in terms of speed, accuracy, and robustness. For instance, it costs only 2 GPU hours to recover a road surface of $600\times 600$ square meters from thousands of images. Notably, RoMe's capability extends beyond mere reconstruction, offering significant value for auto-labeling tasks in autonomous driving applications. All related data and code are available at GitHub. IEEE

关键词： Semantics

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Drilling process of indexable drill bit based on Coupled Eulerian-Lagrangian method:A simulation study

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Chinese Journal of Aeronautics 2024年第11期37卷 477-492页

作者： Desheng HU Caixu YUE Xianli LIU Zhipeng JIANG Yongshi XU Junhui LU Steven Y.LIANG Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

42CrMo steel has the characteristics of high strength,high wear resistance,high impact resistance,and fatigue ***,drilling 42CrMo steel has always been a challenging *** indexable drill bit has the advantages of high processing efficiency and low processing cost and has been widely used in the field of aerospace hole *** better understand the machining mechanism of the indexable drill bit,this paper uses the Coupled EulerianLagrangian method(CEL)to simulate the three-dimensional drilling model for the first *** simulation results of the drilling force obtained by the CEL method and Lagrangian method are compared with the experimental *** is verified that the CEL method is easy to converge and can avoid the problem of program interruption caused by mesh distortion,and the CEL simulation value is more consistent with the actual ***,the simulation results of cutting force and blade cutting edge node temperature under different process parameters are *** variation of time domain cutting force,frequency domain cutting force and tool temperature with process parameters are *** study provides a new method for the prediction of cutting performance and the optimization of process parameters of indexable drills.

关键词： 42CrMo steel Coupled EulerianLagrangian method Indexable drill bit Drilling force Process parameters

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Optimization of pressurization process in low-pressure casting of a 5.4-ton gigantic C95800 copper alloy casting

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China Foundry 2024年第6期21卷 717-726页

作者： Zi-ao Qiu Xin-yi Zhao Chao-jun Zhang Jun-liu Yang Rui-yun Shi Tang-qi Lü Xiao-lei Yu Qiu-shi Chen Lin-lin Quan Lun-yong Zhang Fu-yang Cao Jian-fei Sun National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212000JiangsuChina Shanghai Marine Equipment Research Institute Shanghai 200031China Dalian Marine Propeller Co Ltd.Dalian 116021LiaoningChina

During the low-pressure casting of extra-large size C95800 copper alloy components,traditional linear pressurization technique leads to a rapid surge of liquid metal inlet velocity at the regions where the mold cavity cross-section *** rapid increasement of liquid metal inlet velocity causes serious entrapment of gas and oxide films,and results in various casting defects such as the bifilm *** defects detrimentally deteriorate mechanical properties of the *** address this issue,an innovative nonlinear pressurization strategy timely matching to the casting structure was *** pressurization rate decreases at sections where the cross-section widens,but it gradually increases as the liquid metal level *** this way,the inlet velocity remains below a critical threshold to prevent the entrapment of gas and oxide *** analyses involving numerical simulations and casting verification illustrate that the nonlinear pressurization technique,compared to the linear pressurization,effectively diminishes both the size and number of bifilm ***,the nonlinear pressurization method enhances the casting yield strength by 10%,tensile strength by 14%,and elongation by 10%.Examination through scanning electron microscopy highlights that the bifilm defects arising from the linear pressurization process result in the reduction of the castings’mechanical *** observations underscore the efficacy of nonlinear pressurization in enhancing the quality and reliability of gigantic castings,as exemplified by a 5.4-ton extra-large sized C95800 copper alloy propeller hub with complex structures in the current study.

关键词： gigantic copper alloy casting C95800 low-pressure casting nonlinear pressurization process

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3D-printed Lunar regolith simulant-based geopolymer composites with bio-inspired sandwich architectures

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Journal of Advanced Ceramics 2023年第3期12卷 510-525页

作者： Siqi Ma Yuqi Jiang Shuai Fu Peigang He Chengyue Sun Xiaoming Duan Dechang Jia Paolo Colombo Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Key Laboratory of Advanced Structural–Functional Integration Materials&Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China Max Planck Institute for Polymer Research Mainz 5512Germany Laboratory for Space Environment and Physical Sciences Harbin Institute of TechnologyHarbin 150001China Department of Industrial Engineering University of PadovaPadova 35122Italy Department of Materials Science and Engineering The Pennsylvania State UniversityPhiladelphia 16802USA

Over time,natural materials have evolved to be lightweight,high-strength,tough,and damage-tolerant due to their unique biological ***,combining biological inspiration and structural design would provide traditional materials with a broader range of performance and ***,the application of an ink-based three-dimensional(3D)printing strategy to the structural design of a Lunar regolith simulant-based geopolymer(HIT-LRS-1 GP)was first reported,and high-precision carbon fiber/quartz sand-reinforced biomimetic patterns inspired by the cellular sandwich structure of plant stems were *** study demonstrated how different cellular sandwich structures can balance the structure–property relationship and how to achieve unprecedented damage tolerance for a geopolymer *** results presented that components based on these biomimetic architectures exhibited stable non-catastrophic fracture characteristics regardless of the compression direction,and each structure possessed effective damage tolerance and anisotropy of mechanical *** results showed that the compressive strengths of honeycomb sandwich patterns,triangular sandwich patterns,wave sandwich patterns,and rectangular sandwich patterns in the Y-axis(Z-axis)direction were 15.6,17.9,11.3,and 20.1 MPa(46.7,26.5,23.8,and 34.4 MPa),respectively,and the maximum fracture strain corresponding to the above four structures could reach 10.2%,6.7%,5.8%,and 5.9%(12.1%,13.7%,13.6%,and 13.9%),respectively.

关键词： Lunar regolith simulant(LRS) three-dimensional(3D)printing geopolymer(GP) in situ resource utilization(ISRU) bio-inspired patterns damage tolerance

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Searching for the Effects of Momentum in Tennis and its Applications 11

Searching for the Effects of Momentum in Tennis and its Appl...

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11th International Conference on Information technology and Quantitative Management, ITQM 2024

作者： Zhong, Muhui Liu, Zikang Liu, Pinyan Zhai, Ming School of International Studies Harbin Institute of Technology Harbin150006 China School of computer science and technology Harbin Institute of Technology Harbin150006 China School of Energy Science and Engineering Harbin Institute of Technology Harbin150006 China

In sports, a team or athlete may feel they have momentum, or "power/strength" during a game, but this phenomenon is difficult to measure. Furthermore, it is not clear how various events during a match create or change momentum. This paper presents an approach to quantifying ‘momentum' by introducing a composite model integrating a Logistic Regression Model and a LASSO-based Sparse ARMAX Model to predict momentum shifts and guide strategic decisions during games. The combined model addresses both static and dynamic aspects of momentum, culminating in a comprehensive prediction of momentum trends. The model's robustness is evidenced by its high accuracy rates across different tennis matches and gender scenarios (95.6%, 94.9%, and 95.5%). This paper's findings confirm momentum's measurable impact on sports outcomes, offering a scientific basis for tactical decision-making. © 2024 The Authors.

关键词： Logistic regression

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