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Microstructure Evolution and Phase Transformation of Ti–6.5Al–2Zr–Mo–V Alloy During Thermohydrogen Treatment

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 505-513页

作者： Hong-Chao Kou han-lei zhang Yu-Dong Chu Dong Huang Hai Nan Jin-Shan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical University Beijing Institute of Aeronautical Materials

Thermohydrogen treatment （THT） is an effective way to refine microstructure and improve the mechanical properties of the titanium alloys. In the current work, as-cast Ti-6.5Al-2Zr-Mo-V alloy was hydrogenated with different hydrogen contents and processed solution aging. Accordingly, the microstructure evolution and phase transformation were analyzed. Results show that during solution aging, eutectoid decomposition occurs and the product is a mixture of coarse primaryα, fine eutectoid product and undecomposed βH. The size of primary α is closely dependent on the hydrogen content, and large primary α can be obtained at medium hydrogen content. Further, the influence of hydrogen content on the growth of primary α phase was revealed. The primary α is much fine, and the eutectoid product is relatively homo- geneous with 0.984 wt% H. After THT, the ultimate strength is beyond 1,100 MPa that has increased by 23.15% compared with that in as-cast state.

关键词： Titanium alloy Hydrogen Heat treatment Phase transformation Eutectoid decomposition Mechanical property

Fiber optic monitoring of an anti-slide pile in a retrogressive landslide

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 333-343页

作者： lei zhang Honghu Zhu Heming han Bin Shi School of Water Resources and Environment China University of GeosciencesBeijing100084China State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing100084China School of Earth Sciences and Engineering Nanjing UniversityNanjing210023China School of Civil and Environmental Engineering Nanyang Technological University639798Singapore

Anti-slide piles are one of the most important reinforcement structures against landslides,and evalu-ating the working conditions is of great significance for landslide *** widely adopted analytical methods of pile internal forces include cantilever beam method and elastic foundation beam ***,due to many assumptions involved in calculation,the analytical models cannot be fully applicable to complex site situations,*** with multi-sliding surfaces and pile-soil interface separation as discussed *** view of this,the combination of distributed fiber optic sensing(DFOS)and strain-internal force conversion methods was proposed to evaluate the working conditions of an anti-sliding pile in a typical retrogressive landslide in the Three Gorges reservoir area,*** optical time domain reflectometry(BOTDR)was utilized to monitor the strain distri-bution along the ***,by analyzing the relative deformation between the pile and its adjacent inclinometer,the pile-soil interface separation was ***,the internal forces of the anti-slide pile were derived based on the strain-internal force conversion *** to the ratio of calculated internal forces to the design values,the working conditions of the anti-slide pile could be *** results demonstrated that the proposed method could reveal the deformation pattern of the anti-slide pile system,and can quantitatively evaluate its working conditions.

关键词： Anti-slide pile Multi-sliding surface Pile-soil interface Brillouin optical time domain reflectometry (BOTDR) Geotechnical monitoring Reservoir landslide

Bio-Based Waterborne Poly(Vanillin-Butyl Acrylate)/MXene Coatings for Leather with Desired Warmth Retention and Antibacterial Properties

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Engineering 2024年第5期36卷 250-263页

作者： Jianzhong Ma Li Ma lei zhang Wenbo zhang Qianqian Fan Buxing han College of Bioresources Chemical and Materials Engineering Shaanxi University of Science and TechnologyXi’an 710021China Xi’an Key Laboratory of Green Chemicals and Functional Materials Xi’an 710021China College of Chemistry and Chemical Engineering Shaanxi University of Science and TechnologyXi’an 710021China Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology Shaanxi University of Science and TechnologyXi’an 710021China Institute of Chemistry Chinese Academy of SciencesBeijing 100190China

This study presents a solvent-free,facile synthesis of a bio-based green antibacterial agent and aromatic monomer methacrylated vanillin(MV)using *** resulting MV not only imparted antibacterial properties to coatings layered on leather,but could also be employed as a green alternative to petroleum-based carcinogen styrene(St).Herein,MV was copolymerized with butyl acrylate(BA)to obtain waterborne bio-based P(MV-BA)miniemulsion via miniemulsion ***,MXene nanosheets with excellent photothermal conversion performance and antibacterial properties,were introduced into the P(MV-BA)miniemulsion by ultrasonic *** the gradual solidification of P(MV-BA)/MXene nanocomposite miniemulsion on the leather surface,MXene gradually migrated to the surface of leather coatings due to the cavitation effect of ultrasonication and amphiphilicity of MXene,which prompted its full exposure to light and bacteria,exerting the maximum photothermal conversion efficiency and significant antibacterial *** particular,when the dosage of MXene nanosheets was 1.4 wt%,the surface temperature of P(MV-BA)/MXene nanocomposite miniemulsioncoated leather(PML)increased by about 15℃ in an outdoor environment during winter,and the antibacterial rate against Escherichia coli and Staphylococcus aureus was nearly 100%under the simulated sunlight treatment for 30 ***,the introduction of MXene nanosheets increased the air permeability,water vapor permeability,and thermal stability of these *** study provides a new insight into the preparation of novel,green,and waterborne bio-based nanocomposite coatings for leather,with desired warmth retention and antibacterial *** can not only realize zerocarbon heating based on sunlight in winter,reducing the use of fossil fuels and greenhouse gas emissions,but also improve ability to fight off invasion by harmful bacteria,viruses,and other microorganisms.

关键词： MXene nanosheets Vanillin Styrene substitute Leather coating Photothermal conversion Warmth retention Antibacterial properties

PRX1-positive mesenchymal stem cells drive molar morphogenesis

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International Journal of Oral Science 2024年第2期16卷 293-305页

作者： Xiaoqiao Xu Xuyan Gong lei zhang han zhang Yao Sun Department of Implantology Stomatological Hospital and Dental School of Tongji UniversityShanghai Engineering Research Center of Tooth Restoration and RegenerationShanghaiChina

Mammalian teeth,developing inseparable from epithelial-mesenchymal interaction,come in many shapes and the key factors governing tooth morphology deserve to be *** merging single-cell RNA sequencing analysis with lineage tracing models,we have unearthed a captivating correlation between the contrasting morphology of mouse molars and the specific presence of PRX1^(+)cells within *** PRX1^(+)cells assume a profound responsibility in shaping tooth morphology through a remarkable divergence in dental mesenchymal cell *** into the mechanisms,we have discovered that Wnt5a,bestowed by mesenchymal PRX1^(+)cells,stimulates mesenchymal cell proliferation while orchestrating molar morphogenesis through WNT signaling *** loss of Wnt5a exhibits a defect phenotype similar to that of *** addition of WNT5A can successfully reverse the inhibited cell proliferation and consequent deviant appearance exhibited in Prx1-deficient tooth *** findings bestow compelling evidence of PRX1-positive mesenchymal cells to be potential target in regulating tooth morphology.

关键词： Wnt5a mesenchymal inhibited

Bifunctional core–shell co-catalyst for boosting photocatalytic CO_(2) reduction to CH_(4)

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Nano Research 2024年第3期17卷 1259-1266页

作者： Fangxu Dai Mingming zhang Jishu han Zhenjiang Li Shouhua Feng Jun Xing lei Wang Key Laboratory of Eco-chemical Engineering Ministry of EducationCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China College of Materials Science and Engineering Qingdao University of Science and TechnologyQingdao 266042China College of Environment and Safety Engineering Qingdao University of Science and TechnologyShandong Engineering Research Center for Marine Environment Corrosion and Safety ProtectionQingdao 266042China

Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy ***,achieving high CH_(4) activity and selectivity remains a significant ***,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and**** photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction *** work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.

关键词： bifunctional co-catalyst core–shell photocatalytic CO_(2)reduction

HIV Infection and Associated Factors Among Out-of-School MSM Aged 16–24 Years—6 Cities and Tianjin Municipality,China,2022–2023

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China CDC weekly 2024年第3期6卷 45-50页

作者： Hui Liu Qiyu Zhu lei zhang Yujing Liu Peng Xu Mengjie han National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Chinese Association of STD and AIDS Prevention and Control BeijingChina Beijing Chaoyang Kangzhong Health and Education Center BeijingChina

What is already known about this topic?Approximately 80%of newly diagnosed human immunodeficiency virus(HIV)cases among individuals aged 15–24 years in China are attributed to out-ofschool *** is added by this report?This study presents findings on HIV prevalence and comprehensive insights into HIV service utilization,risky behaviors,and prevention knowledge among young out-of-school men who have sex with men(MSM)aged 16–24 years in *** population exhibits a disproportionately high burden of HIV,with only 51.6%of HIV cases previously *** are the implications for public health practice?HIV services should be expanded to include these key *** interventions are needed to remove barriers to regular HIV services faced by young key populations.

关键词： prevention remove expanded

Weakly supervised point cloud segmentation via deep morphological semantic information embedding

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CAAI Transactions on Intelligence Technology 2024年第3期9卷 695-708页

作者： Wenhao Xue Yang Yang lei Li Zhongling Huang Xinggang Wang Junwei han Dingwen zhang School of Automation Northwestern Polytechnical UniversityXi'anChina Institute of Mechanical and Electrical Engineering BeijingChina School of Electronic Information and Communications Huazhong University of Science and TechnologyWuhanChina

Segmenting the semantic regions of point clouds is a crucial step for intelligent agents to understand 3D *** supervised point cloud segmentation is highly desirable because entirely labelling point clouds is highly time-consuming and *** the low-costing labelling of 3D point clouds,the scene-level label is one of the most effortless label ***,due to the limitation of classifier discriminative capability and the orderless and structurless nature of the point cloud data,existing scene-level method is hard to transfer the semantic information,which usually leads to the under-activated or over-activated *** this end,a local semantic embedding network is introduced to learn local structural patterns and semantic ***,the proposed network contains graph convolution-based dilation and erosion embedding modules to implement‘inside-out’and‘outside-in’semantic information dissemination ***,the proposed weakly supervised learning framework could achieve the mutual propagation of semantic information in the foreground and *** experiments on the widely used ScanNet benchmark demonstrate the superior capacity of the proposed approach when compared to the current alternatives and baseline models.

关键词： artificial intelligence computer vision deep learning

Multilevel Micro Structures of the Clam Make the Sealing Even Tighter

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Journal of Bionic Engineering 2024年第3期21卷 1442-1452页

作者： Daobing Chen Xiaolong zhang Junqiu zhang Zhiwu han Ruteng Wang Zhen Lin Yifeng lei Longjian Xue Sheng Liu The Institute of Technological Science Wuhan UniversityWuhan430072China School of Power and Mechanical Engineering Wuhan UniversityWuhan430072China The Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityChangchun130022China Institute of Structured and Architected Materials Liaoning Academy of MaterialsShenyang110167China

Excellent fluid sealing performance is crucial to ensuring the safety of important equipment,especially in aerospace field,such as space capsule and fuel *** frequently opening and closing of the sealing devices is particularly *** by this background,clams(Mactra chinensis)which can open and close their double shells with superior sealing performance,are studied in this ***,we show that the clam’s sealing ability is the result of its unique multilevel intermeshing microstructures,including hinge teeth and *** microstructures,which resemble gear teeth,engage with each other when the shell closes,forming a tight structure that prevents the infiltration of water from the ***,the presence of micron blocks prevents the penetration of finer *** simulation results of the bionic end seal components show that the multilevel microstructure has a superior sealing *** research is expected to be applied to undersea vehicles that require frequent door opening and closing.

关键词： Multilevel micro structures Opening and closing components Clam Sealing Bionic

Synergistic Effect of Nitrogen/Phosphorus Co-Doping and Molybdenum Carbide Induced Electron Redistribution of Carbon Layer to Boost Hydrogen Evolution Reaction

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Chinese Journal of Chemistry 2024年第1期42卷 55-60页

作者： Jiamin Xiao Peng Li Yanyan Sun Heng Liu Javid Khan handong zhang han Zhou Yaqiong Su Shuangyin Wang lei han College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean EnergyHunan UniversityChangshaHunan 410082China School of Chemistry Engineering Research Center of Energy Storage Materials and Devices Ministry of EducationXi'an Key Laboratory of Sustainable Energy Materials ChemistryState Key Laboratory of Electrical Insulation and Power EquipmentXi'an Jiaotong UniversityXi'anShaanxi 710049China School of Materials Science and Engineering Central South UniversityChangshaHunan 410083China state Key Laboratory of Chem/Bio-Sensingand Chemometrics College of Chemistry and Chemical EngineeringHunan University ChangshaHunan 410082China Laboratory of Inorganic Materials and Catalysis Department of Chemical Engineering and ChemistryEindhoven University of Technology P.O.Box5135600 MB EindhovenThe Netherlands

The development of highly efficient non-precious-metal-based electrocatalysts for the hydrogen evolution reaction is imperative for promoting the large-scale application of electrochemical water ***,nitrogen/phosphorus co-doped carbon nanorods encapsulated Mo_(2)C nanoparticles(Mo_(2)C@PNc)have been prepared by pre-phosphating treatment in combination of the coordination with polydopamine and the subsequent *** phosphating temperature has a significant effect on the content of phosphorus within the resultant Mo_(2)C@PNC,and the optimal catalyst delivers superior HER activity with the low overpotential of 104 mV at a current density of 10 mAcm^(-2) and good stability for 8 h,which has been theoretically demonstrated to originate from the synergistic effect between P doping and Mo_(2)C induced electron redistribution of nitrogen-doped carbon layer.

关键词： Molybdenum carbide N/P co-doped carbon Hydrogen evolution Synergistic effect Electron redistribution Comprehensive