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Cortical activity in patients with high-functioning ischemic stroke during the Purdue Pegboard Test:insights into bimanual coordinated fine motor skills with functional near-infrared spectroscopy

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Neural Regeneration Research 2024年第5期19卷 1098-1104页

作者： Siyun Chen Mengchai Mao Guangyue Zhu Yufeng Chen Yuqi Qiu Bin Ye dongsheng xu The Second Rehabilitation Hospital of Shanghai ShanghaiChina College of Rehabilitation Science Shanghai University of Traditional Chinese MedicineShanghaiChina Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation Ministry of EducationShanghaiChina School of Statistics East China Normal UniversityShanghaiChina The Third Rehabilitation Hospital of Shanghai ShanghaiChina Tongji University ShanghaiChina Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine ShanghaiChina

After stroke,even high-functioning individuals may experience compromised bimanual coordination and fine motor dexterity,leading to reduced functional independence.Bilateral arm training has been proposed as a promising intervention to address these deficits.However,the neural basis of the impairment of functional fine motor skills and their relationship to bimanual coordination performance in stroke patients remains unclear,limiting the development of more targeted interventions.To address this gap,our study employed functional near-infrared spectroscopy to investigate cortical responses in patients after stroke as they perform functional tasks that engage fine motor control and coordination.Twenty-four high-functioning patients with ischemic stroke(7 women,17 men;mean age 64.75±10.84 years)participated in this cross-sectional observational study and completed four subtasks from the Purdue Pegboard Test,which measures unimanual and bimanual finger and hand dexterity.We found significant bilateral activation of the sensorimotor cortices during all Purdue Pegboard Test subtasks,with bimanual tasks inducing higher cortical activation than the assembly subtask.Importantly,patients with better bimanual coordination exhibited lower cortical activation during the other three Purdue Pegboard Test subtasks.Notably,the observed neural response patterns varied depending on the specific subtask.In the unaffected hand task,the differences were primarily observed in the ipsilesional hemisphere.In contrast,the bilateral sensorimotor cortices and the contralesional hemisphere played a more prominent role in the bimanual task and assembly task,respectively.While significant correlations were found between cortical activation and unimanual tasks,no significant correlations were observed with bimanual tasks.This study provides insights into the neural basis of bimanual coordination and fine motor skills in high-functioning patients after stroke,highlighting task-dependent neural responses.The findings also suggest that patients wh

关键词： bilateral arm training bimanual coordination cortical activity fine motor dexterity functional near-infrared spectroscopy(fNIRS) high-functioning Purdue Pegboard Test stroke

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Refinement ofα′Martensite by Oxygen in Selective Laser Melted Ti-6Al-4V

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 777-792页

作者： Hasfi FNurly Jinhu Zhang Dechun Ren Yusheng Cai Haibin Ji dongsheng xu Zhicheng Dong Hao Wang Qingmiao Hu Jiafeng Lei Rui Yang School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials and Chemistry/Interdisciplinary Centre for Additive Manufacturing University of Shanghai for Science and TechnologyShanghai 200093China Centre for Adaptive System Engineering ShanghaiTech UniversityShanghai 201210China

Oxygen is crucial in influencing the microstructure evolution of selective laser melted(SLMed)Ti–6Al–4V,significantly impacting its applicability in various sectors.Therefore,this study investigates the influnce of oxygen on microstructure evolution,particularlyα′martensite transformation and refinement mechanisms.Four alloys,Ti–6Al–4V–xO(x=0.11,0.16,0.21,and 0.25 wt%),were fabricated by the SLM process.The martensite start temperature(M_(s))of Ti–6Al–4V,as evaluated by computation,is 656.8°C,and oxygen was found to increase the M_(s) by about 10°C per 0.1 wt%.The SLMed alloy samples exhibit[001]_(β)growth texture along the build direction.Crystallographic analysis of martensite morphology suggests internal twinning on{1011}planes as the lattice invariant strain,which becomes more predominant with increasing oxygen content.Refinement of α′martensite plates by oxygen is due to increased lattice distortion,reduced prior β grain size,and oxygen segregation toβgrain boundaries.Our findings contribute to improving the understanding of the effect of oxygen on the transformation mechanism ofα′martensite during SLM of Ti–6Al–4V.

关键词： Selective laser melting α′Martensite Martensite start temperature Oxygen Ti-6Al-4V

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Improved spatio-temporal alignment measurement method for hull deformation

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Journal of Systems Engineering and Electronics 2024年第2期35卷 485-494页

作者： xu dongsheng YU Yuanjin ZHANG Xiaoli PENG Xiafu School of Automation Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Xiamen UniversityXiamen 361005China

In this paper,an improved spatio-temporal alignment measurement method is presented to address the inertial matching measurement of hull deformation under the coexistence of time delay and large misalignment angle.Large misalignment angle and time delay often occur simultaneously and bring great challenges to the accurate measurement of hull deformation in space and time.The proposed method utilizes coarse alignment with large misalignment angle and time delay estimation of inertial measurement unit modeling to establish a brand-new spatiotemporal aligned hull deformation measurement model.In addition,two-step loop control is designed to ensure the accurate description of dynamic deformation angle and static deformation angle by the time-space alignment method of hull deformation.The experiments illustrate that the proposed method can effectively measure the hull deformation angle when time delay and large misalignment angle coexist.

关键词： inertial measurement spatio-temporal alignment hull deformation

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Seismic Performance of Assembled Shear Wall with Defective Sleeve Connection

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Computer Modeling in Engineering & Sciences 2022年第4期131卷 199-217页

作者： Hua Yan Bo Song dongsheng xu Guodong Zhang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China School of Architecture and Engineering Langfang Normal UniversityLangfang065000China Beijing International Science and Technology Cooperation Base for Earthquake Research on Mass Transit Railway Project Beijing100083China

In this paper,three kinds of shear walls with full sleeve grouting,fully defective sleeve and partially defective are designed for finite element analysis to analyze the influence of defects on the seismic performance of shear walls.The research shows that at the beginning of loading(5 s),the three models begin to appear compressive damage at the bottom of the wall in all three models.The damage of the defect-free model develops rapidly,and the damage of the fully defective model is basically the same as that of the partially defective model.With the gradual increase of displacement control(15 s),the compressive damages at the foot of the wall in the defect-free and partially defective grouting model are obvious,with plastic hinge formed in the foot of the wall,and the phenomenon of development along the pier body showing up.When the structure is damaged,the overall compressive damages of the wall in the defect-free and partially defective models are obvious,and the damage on the defective side of the partially defective model is slightly deficient.While the maximum stress of pre-stressed reinforcement in the defect-freemodel is concentrated at the top of the sleeve,themaximumstress of the pre-stressed steel bar in the fully defective model appears at the end of the steel bar in the sleeve.The hysteresis curve shape of the non-defectmodel and partially defective model are basically the same,showing a“shuttle”shape with a sound energy dissipation effect.The hysteresis curve shape of the fully defective model appears an obvious“pinch”phenomenon.The yield displacement levels of the defect-free and partially defective models are smaller than that of the fully defective model structure.The stiffness degradation curves of the three models basically overlap with one another.Before the limit displacement,the stiffness results of the non-defect model and the partially defective model are greater than that of the fully defective model.When the displacement is loaded to 20 mm,the stiffness degradation of the three models is

关键词： Grouting sleeve defects shear wall finite element analysis seismic performance

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A fiber Bragg grating based earth and water pressures transducer with three-dimensional fused deposition modeling for soil mass

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第2期14卷 663-669页

作者： Yue Qin Qiankun Wang dongsheng xu Jiaming Yan Shanshan Zhang School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan430070China

A novel fiber Bragg grating(FBG)sensor with three-dimensional(3D)fused deposition modeling(FDM)approach is proposed for effective stress measurement in soil mass.The three-diaphragm structure design is developed to measure earth and water pressures simultaneously.The proposed transducer has advantages of small size,high sensitivity,low cost,immunity to electromagnetic interference and rapid prototyping.The working principle,design parameters,and manufacturing details are discussed.The proposed transducer was calibrated for earth and water pressures measurement by using weights and a specially designed pressure chamber,respectively.The calibration results showed that the wavelength of the transducer was proportional to the applied pressure.The sensitivity coefficients of the earth and water pressures were 12.633 nm/MPa and 6.282 nm/MPa,respectively.Repeated tests and error analysis demonstrated the excellent stability and accuracy of the earth and water pressure measurements.The performance of the proposed transducer was further verified by a model experimental test and numerical analysis,which indicated that the proposed transducer has great potential for practical applications.

关键词： Fused deposition modeling(FDM) Fiber bragg-grating(FBG)sensor Earth pressure Water pressure

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A phase-field model for simulating the growth ofαsideplates with branching in titanium alloys

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Journal of Materials Science & Technology 2022年第28期123卷 154-158页

作者： Jinhu Zhang Min Qi Haisheng xu Hao Wang Yingjie Ma dongsheng xu Rui Yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China University of Shanghai for Science and Technology Shanghai 200093China

In recent years,titanium and titanium alloys are widely used in the fields of aerospace,oceans,etc.due to their high strength to weight ratio,good toughness and excellent corrosion resistance[1].Various microstructures and mechanical properties can be ob-tained simply by varying the thermomechanical processing or heat treatment.As an example,the Widmanstätten structure may pos-sess good tensile strength,fracture toughness,fatigue properties and high resistance to crack growth[2].It is formed when tita-nium alloys are cooled from theβphase region.During the cooling process,αGB(grain boundaryα)may first nucleates at the priorβgrain boundary,and then theαW(Widmanstättenα)grows fromαGB and forms intragranularαsideplates colony[3].The compli-cated evolution process is difficult to characterize experimentally,since the microstructures observed experimentally are mostly ul-timate results,but not a dynamic evolution process.

关键词： alloys toughness resistance

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An Improved Method Based on TODIM and TOPSIS for Multi-Attribute Decision-Making with Multi-Valued Neutrosophic Sets

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Computer Modeling in Engineering & Sciences 2021年第11期129卷 907-926页

作者： dongsheng xu Lijuan Peng School of Science Southwest Petroleum UniversityChengdu610500China

Due to the complexity of decision-making problems and the subjectivity of decision-makers in practical application,it is necessary to adopt different forms of information expression according to the actual situation of specific decision-making problems and choose the best method to solve them.Multi-valued neutrosophic set,as an extension of neutrosophic set,can more effectively and accurately describe incomplete,uncertain or inconsistent information.TODIM and TOPSIS methods are two commonly used multi-attribute decision-making methods,each of which has its advantages and disadvantages.This paper proposes a new method based on TODIM and TOPSIS to solve multi-attribute decision-making problems under multi-valued neutrosophic environment.After introducing the related theory of multi-valued neutrosophic set and the traditional TODIM and TOPSIS methods,the new method based on a combination of TODIM and TOPSIS methods is described.And then,two illustrative examples proved the feasibility and validity of the proposed method.Finally,the result has been compared with some existing methods under the same examples and the proposed method’s superiority has been proved.This paper studies this kind of decision-making problem from algorithm idea,algorithm steps and decision-making influencing factors.

关键词： Multi-valued neutrosophic set TODIM TOPSIS multi-attribute decision-making

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Flow behavior and processing map for hot deformation of ATI425 titanium alloy

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Journal of Materials Science & Technology 2018年第4期34卷 679-688页

作者： Qinggang Meng Chunguang Bai dongsheng xu Institute of Metal Research Chinese Academy of Sciences

Flow behavior and processing map play important roles in the hot deformation process of titanium alloys. In this research, compression Gleeble tests have been carried out to investigate the stress-strain relationship at temperatures ranging from 700 to 1000 ℃ and strain rates ranging from 0.001 to 1 s-1 for ATI 425 titanium alloy. Arrhenius type constitutive equation was obtained to describe the compressive flow behavior with modification of additional deformation dead zone, friction model, temperature model and strain rate. The introduction of novel calculation method for α value in Arrhenius equation gives more accurate fitting than traditional one. Processing maps were drawn based on the distribution of dissipator co-content, and optimized deformation temperature and strain rate range obtained. It is proven to be accurate and effective through the experimental results. The microstructure analysis shows that more dynamic recrystallization can be achieved in the area with larger ηvalue on the processing map.

关键词： Titanium alloy Flow stress Constitutive equation Processing map

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Dynamic recrystallization behavior of GH4169G alloy during hot compressive deformation

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Journal of Materials Science & Technology 2019年第9期35卷 1851-1859页

作者： Dan Jia Wenru Sun dongsheng xu Fang Liu University of Chinese Academy of Sciences Beijing100049China Institute of Metal Research Chinese Academy of SciencesShenyang110016China

The microstructure evolutions and nucleation mechanisms of GH4169G alloy were studied by optical microscope, electron backscatter diffraction (EBSD) and transmission electron microscope (TEM). The hot compression tests were performed different imposed reductions in the range of true strain from 0.12 to 1.2 at the temperatures of 930 °-1050 ° with strain rates of 0.01 s^-1-l s^-1. It is found that cumulative and local misorientation increase firstly and then decrease when the strain is increased due to the progress of dynamic recrystallization (DRX). The low angle boundaries (LAGBs) rapidly develop to high angle boundaries (HAGBs) at relatively high deformation temperature or the low strain rate. There are three DRX mechanisms observed for GH4169 G alloy during hot deformation. Discontinuous dynamic recrystallization (DDRX) as the dominant mechanism for GH4169 G alloy is characterized by typical necklace structures and bulged-original boundaries. Besides, different deformation bands with dislocation cells formed in deformed matrix at low temperature and large strain, which indicates that continuous dynamic recrystallization (CDRX) contributed to the DRX process. The twin boundaries lost their coherent characteristics and provide sites for nucleation, which also accelerates the nucleation of DRX.

关键词： GH4169G alloy Dynamic recrystallization Nucleation mechanism

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Heterogeneous precipitate microstructure in titanium alloys for simultaneous improvement of strength and ductility

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Journal of Materials Science & Technology 2022年第29期124卷 150-163页

作者： Mengyuan Hao Pei Li xuexiong Li Tianlong Zhang Dong Wang Qiaoyan Sun Libin Liu Jinshan Li Yuyou Cui Rui Yang dongsheng xu Frontier Institute of Science and Technology State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Thermal Power Research Institute Co.Ltd. Xi’an 710032China

The design of alloys with simultaneous high strength and high ductility is still a difficult challenge.Here,we propose a new approach to designing multi-phase alloys with a synergistic combination of strength and ductility by engineering heterogeneous precipitate microstructures through the activation of different transformation mechanisms.Using a two-phase titanium alloy as an example,phase field simulations are carried out firstly to design heat treatment schedules that involve both conventional nucleation and growth and non-conventional pseudospinodal decomposition mechanisms,and the calculated microstructures have been evaluated by crystal plasticity finite element modeling.According to simulations,we then set a two-step heat treatment to produce bimodalα+βmicrostructure in Ti-10V-2Fe-3Al.Further mechanical testing shows that the ductility of the alloy is increased by~50%and the strength is increased by~10%as compared to its unimodal counterpart.Our work may provide a general way to improve the mechanical properties of alloys through multiscale microstructure design.

关键词： Titanium alloys Phase field simulation Crystal plasticity finite element Two-step aging Pseudospinodal decomposition mechanisms Multiscale heterogeneous microstructure

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