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Machine learning guided automatic recognition of crystal boundaries in bainitic/martensitic alloy and relationship between boundary types and ductile-to-brittle transition behavior

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journal of Materials Science & Technology 2021年第25期84卷 49-58页

作者： x.C.Li j.x.Zhao j.H.Cong R.D.K.Misra x.M.wang x.L.wang C.j.Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Department of Metallurgical Materials and Biomedical EngineeringUniversity of Texas at El Paso500 W.University AvenueEl PasoTX 79968USA

Gradient boosting decision tree(GBDT)machine learning(ML)method was adopted for the first time to automatically recognize and conduct quantitative statistical analysis of boundaries in bainitic microstructure using electron back-scatter diffraction(EBSD)*** spite of lack of large sets of EBSD data,we were successful in achieving the desired accuracy and accomplishing the objective of recognizing the *** with a low model accuracy ofxis-angle pair as characteristic features,the accuracy of the model was significantly enhanced to about 88%when the Euler angle was converted to overall misorientation angle(OMA)and specific misorientation angle(SMA)and considered as important *** this model,the recall score of prior austenite grain(PAG)boundary was~93%,high angle packet boundary(OMA>40°)was~97%,and block boundary was~96%.The derived outcomes of ML were used to obtain insights into the ductile-to-brittle transition(DBTT)***,ML modeling approach suggested that DBTT was not determined by the density of high angle grain boundaries,but significantly influenced by the density of PAG and packet *** study underscores that ML has a great potential in detailed recognition of complex multi-hierarchical microstructure such as bainite and martensite and relates to material performance.

关键词： Machine learning Feature engineering Automatic recognition Lath structure Crystallography

INVESTIGATION OF WO3-DOPED TiO2 FILM COMPOSITE PHOTOCATALYST

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 263-268页

作者： Q.F. Meng K.R. Liu L. jiang Q. Han j.S. Chen x.j. Wei School of Materials & Metallurgy Northeastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 China

The nano--crystal composite WO_3-TiO_2 photocatalyst was prepared by ultrasonic as-sisted sol--gel process. The effects of various factors, such as the crystal form, thesubstrates, the pH, the dissolved oxygen and the ultrasonic on the photocatalytic ac-tivity were investigated in view of the photodegradation of Rhodamine B. The resultsshow that the crystal form of WO_3-TiO_2 film with highest photocatalytic activity isrutile. The introduction of ultrasonic to the course of preparation can accelerate thedeposit time of the sol and increase the photocatalytic activity significantly in view ofthe highest photodegradation of Rhodamine B being 72.7% in 5 hours. The poroustitanium plate is the most suitable substrate in four kinds of investigated materials.Meanwhile the smaller the pH and the higher the concentration of the dissolved oxygenin the solution is, the higher the photodegradation is.

关键词： ultrasonic sol-gel process photocatalytic photodegradation

Human neural stem cell-derived extracellular vesicles protect against ischemic stroke by activating the PI3K/AKT/mTOR pathway

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Neural Regeneration Research 2025年第11期20卷 3245-3258页

作者： jiayi wang Mengke Zhao Dong Fu Meina wang Chao Han Zhongyue Lv Liang wang jing Liu Stem Cell Clinical Research Center The First Affiliated Hospital of Dalian Medical UniversityDalianLiaoning ProvinceChina Dalian Innovation Institute of Stem Cell and Precision Medicine DalianLiaoning ProvinceChina Institute(College)of Integrative Medicine Dalian Medical UniversityDalianLiaoning ProvinceChina

Human neural stem cell-derived extracellular vesicles exhibit analogous functions to their parental cells,and can thus be used as substitutes for stem cells in stem cell therapy,thereby mitigating the risks of stem cell therapy and advancing the frontiers of stem cell-derived *** lays a foundation for the development of potentially potent new treatment modalities for ischemic ***,the precise mechanisms underlying the efficacy and safety of human neural stem cell-derived extracellular vesicles remain unclear,presenting challenges for clinical *** promote the translation of therapy based on human neural stem cell-derived extracellular vesicles from the bench to the bedside,we conducted a comprehensive preclinical study to evaluate the efficacy and safety of human neural stem cell-derived extracellular vesicles in the treatment of ischemic *** found that administration of human neural stem cell-derived extracellular vesicles to an ischemic stroke rat model reduced the volume of cerebral infarction and promoted functional recovery by alleviating neuronal *** human neural stem cell-derived extracellular vesicles reduced neuronal apoptosis by enhancing phosphorylation of phosphoinositide 3-kinase,mammalian target of rapamycin,and protein kinase B,and these effects were reversed by treatment with a phosphoinositide 3-kinase *** findings suggest that human neural stem cell-derived extracellular vesicles play a neuroprotective role in ischemic stroke through activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling ***,we showed that human neural stem cell-derived extracellular vesicles have a good in vivo safety ***,human neural stem cell-derived extracellular vesicles are a promising potential agent for the treatment of ischemic stroke.

关键词： behavior exosome extracellular vesicles ischemic stroke mammalian target of rapamycin(mTOR) middle cerebral artery occlusion neural stem cells neuronal apoptosis phosphoinositide 3-kinase(PI3K) protein kinase B(AKT)

Processing, Microstructure and Mechanical Properties of Ti6Al4V Particles-Reinforced Mg Matrix Composites

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Acta Metallurgica Sinica(English Letters) 2016年第10期29卷 940-950页

作者： x.M.wang x.j.wang x.S.Hu K.Wu M.Y.Zheng School of Materials Science and Engineering Harbin Institute of Technology

Novel Ti6Al4V particles-reinforced AZ91 Mg matrix composites were successfully fabricated by stir casting method. The stirring time in semisolid condition directly affected the particle distribution and the quality of the ingots. Furthermore, the optimal speed of the heating and the liquid stirring could overcome particle settlement caused by the density difference between the matrix and the particles. Ti6Al4V particles distributed uniformly in the composites with different particle contents. The average grain size decreased with the increase in the particle contents. The Ti6A14V particles bonded pretty well with the alloy matrix. In addition, there were some interfacial reactions in the composites. There were rod-like A13Ti phases at the interface. The precipitates extended from the particle surface to the matrix, and they might improve the interfacial bonding strength. The ultimate tensile strength, yield strength and elastic modulus were enhanced as the particle contents increased, and the elongation was much better than that of the same matrix material reinforced with SiC particles. Thus, the novel composites exhibit better comprehensive mechanical properties.

关键词： Magnesium matrix composites Ti6Al4V particles Stir casting Microstructure Mechanicalproperties

SURFACE REACTION OF Ni_3Al WITH WATER VAPOROR OxYGEN

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Acta Metallurgica Sinica(English Letters) 1997年第4期10卷 363-368页

作者： Yx. Chen x.j. Wan and W.x. xu (Institute of Materials Sciences, Shanghai University, Shanghai 200072, China)(Shanghai Iron and Steel Research Institute, Shanghai 200940, China) Shanghai Univ Shanghai China

The kinetics of the surface reactions of single crystal Ni3Al and polycrystal line Ni3Al0.00052 wt% B with water vapor or oxygen was investigated using xPS. Both reactions initiate at less than 1.5×10-6 Pa.s exposure. The reaction of Ni3Al does not saturote with water vapor at 0.43 Pa.s; with oxygen at 8.4×10-2 Pa.s and the oxide formed is Al2O3. The kinetics of these reactions can be used to eaplain the different ductility behavior of Ni3Al-based alloys in various environment.

关键词： Ni_3Al surface reaction xPS hydrogen embrittlement

Optimizing the key parameter to accelerate the recovery of AMOC under a rapid increase of greenhouse gas forcing

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 39-45页

作者： Haolan Ren Fei Zheng Tingwei Cao Qiang wang International Center for Climate and Environment Science(ICCES) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina College of Oceanography Hohai UniversityNanjingChina CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of Sciences and Pilot National Laboratory for Marine Science and Technology(Qingdao)QingdaoChina

Atlantic Meridional Overturning Circulation(AMOC)plays a central role in long-term climate variations through its heat and freshwater transports,which can collapse under a rapid increase of greenhouse gas forcing in climate *** studies have suggested that the deviation of model parameters is one of the major factors in inducing inaccurate AMOC *** this work,with a low-resolution earth system model,the authors try to explore whether a reasonable adjustment of the key model parameter can help to re-establish the AMOC after its *** a new optimization strategy,the extra freshwater flux(FWF)parameter is determined to be the dominant one affecting the AMOC’s *** traditional ensemble optimal interpolation(EnOI)data assimilation and new machine learning methods are adopted to optimize the FWF parameter in an abrupt 4×CO_(2) forcing experiment to improve the adaptability of model parameters and accelerate the recovery of *** results show that,under an abrupt 4×CO_(2) forcing in millennial simulations,the AMOC will first collapse and then re-establish by the default FWF parameter ***,during the parameter adjustment process,the saltier and colder sea water over the North Atlantic region are the dominant factors in usefully improving the adaptability of the FWF parameter and accelerating the recovery of AMOC,according to their physical relationship with FWF on the interdecadal timescale.

关键词： Recovery of AMOC 4×CO_(2)forcing Key parameter Parameter estimation Data assimilation Machine learning

Design of a cationic accelerator enabling ultrafast ion diffusion kinetics in aqueous zinc-ion batteries

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journal of Energy Chemistry 2025年第1期100卷 377-384页

作者： Yawei xiao Qianqian Gu Haoyu Li Mengyao Li Yude wang National Center for International Research on Photoelectric and Energy Materials School of Materials and Energy Yunnan University Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources School of Chemistry and Chemical Engineering Hainan University College of Chemical Engineering Fuzhou University Yunnan Key Laboratory of Carbon Neutrality and Green Low-carbon Technologies Yunnan University

Aqueous zinc-ion batteries are highly favored for grid-level energy storage owing to their low cost and high safety,but their practical application is limited by slow ion *** address this,a strategy has been developed to create a cation-accelerating electric field on the surface of the cathode to achieve ultrafast Zn2+diffusion *** employing electrodeposition to coat MoS2on the surface of BaV6O16·3H2O nanowires,the directional built-in electric field generated at the heterointerface acts as a cation accelerator,continuously accelerating Zn2+diffusion into the active *** optimized Zn2+diffusion coefficient in CC@BaV-6O16·3H2O@MoS2(7.5×10～8cm2s-1) surpasses that of most reported V-based ***,MoS2serving as a cathodic armor extends the cycling life of the Zn-CC@BaV6O16·3H2O@MoS2full batteries to over 10000 *** work provides valuable insights into optimizing ion diffusion kinetics for high-performance energy storage devices.

关键词： Internal electric field Cationic accelerator Ion diffusion kinetics Cathode modification strategy Aqueous zinc ion battery

STUDY OF ANODIC OVERVOLTAGE IN NEODYMIUM ELECTROLYSIS

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Acta Metallurgica Sinica(English Letters) 2003年第5期16卷 355-359页

作者： K.R. Liu, j.S. Chen, Q. Han and x.j. WeiSchool of Materials and Metallurgy, Northeastern University, Shenyang 110004, China Sch. of Mat. and Metall. Northeastern Univ. Shenyang 110004 China

The anodic overvoltage of neodymium electrolysis was determined by slow scanning oscillograrn. The effects of some factors, i.e. the temperature, the anodic current density, the concentration of Nd2O3 and the components of the electrolyte were investigated and the approaches to decrease the anodic overvoltage were also discussed. The results show that the anodic overvoltage increases with the anodic current density and decreases with the increasing temperature. The linear relation between the anodic overvoltage and the current density corresponding to Tafel equation is determined to some extent. The anodic overvoltage decreases with the increasing concentrations of LiF and NdF3. It also decreases by controlling the anodic current density properly, increasing the temperature or the concentrations of LiF and NdF3 and the reducing polar distance.

关键词： neodymium electrolysis anodic overvoltage deposition voltage fluoride

Chinese-version Bt Cotton: How to Get the Benefi ts from IPR

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分子植物育种 2007年第2期5卷 296-297页

作者： x.j. Fang HITAR Consultancy in CropScience Beijing 100080 China

Chinese scientists started to fully synthesize the Bacillus thuringiensis (Bt) Cry1A gene in 1991. By the end of 1992, Biotechnology Research Institute of Chinese Academy of Agricultural Sciences (BRI-CAAS) success-

关键词：中国生物技术农业科学黄萎病镰刀霉棉花