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Single atom catalyst towards ammonia synthesis at mild conditions

science China Chemistry 2018年第9期61卷 1045-1046页

作者： Zhiwei Fang Guihua Yu Materials Science and Engineering Program and Department of Mechanical Engineering The University of Texas at Austin

Nitrogen is an essential nutrient element for all living organisms,however in its sufficient molecular form,nitrogen could not be utilized to meet the crucial need for global food requirements or industrial production due to its strong nonpolar N≡N triple ***,nitrogen fixation is an essential transformation but this only occurs in the nature with the help of nitrogenases[1].Although nitrogen can be artificially transformed into ammonia through the wellestablished Haber-Bosch process,the reaction is accomplished under drastic conditions,

关键词：氨合成温和条件催化剂原子氮固定工业生产有机体三元组

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Coupled effects of morphology/length scale of the microstructure and microsegregation on the corrosion behaviour of a single-phase Zn-1wt%Cu alloy

Next Materials

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Next materials 2025年 8卷

作者： Miranda, Romulo S. Vida, Talita Ligeiro, Henrique S. Cheung, Noé Simões, Fábio R. Garcia, Amauri Brito, Crystopher Postgraduate Program in Engineering São Paulo State University Guaratinguetá Brazil Department of Aeronautical Engineering School of Engineering/São Paulo State University São João da Boa Vista Brazil Department of Manufacturing and Materials Engineering University of Campinas Campinas Brazil Institute of Marine Science Federal University of São Paulo Santos Brazil

Zn-Cu alloys are promising for biomaterials due to their unique properties. Unlike most metallic alloys, Zn-Cu exhibits a partition coefficient greater than 1, leading to solvent segregation. This study aims to explore how microsegregation and cellular microstructure affect the corrosion behaviour of a Zn-1wt%Cu alloy. Three specimens, with cellular spacings of approximately 8, 16, and 32 µm, were extracted from a directionally solidified casting. Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization techniques were used to assess the corrosion performance in NaCl solutions. The results showed that coarser cellular structures demonstrated higher corrosion resistance, evidenced by greater charge transfer resistances and lower current densities. Corrosion initiated at the Cu-poor cellular boundaries, acting as anodic regions, and became more severe in finer microstructures. In contrast, larger cells with fewer boundaries exhibited less generalised corrosion, confirming that microstructural coarsening improves corrosion resistance. © 2025 The Authors

关键词： Biodegradable Zn-Cu alloys Corrosion behaviour in NaCl Electrochemical performance of biomaterials Galvanic corrosion mechanisms Microstructural refinement

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Intermetallic Compound Formation and Growth Behavior Between Ruthenium and Tin System

Intermetallic Compound Formation and Growth Behavior Between...

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International Conference on Electronics Packaging (ICEP)

作者： Hsiu-mei Yang Tzu-hsuan Huang Yu-hsuan Lin Min-cian Chen Shih-kang Lin Department of Materials Science and Engineering National Cheng Kung University Tainan Taiwan Program on Semiconductor Packaging and Testing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan Taiwan Taiwan Semiconductor Manufacturing Company Limited Hsinchu Taiwan

ISBN: (数字)9784991191190

ISBN: (纸本)9798331514747

This study investigates the liquid/solid reflow process under a vacuum environment of 1 Pa at reflow temperatures of 300°C for different reaction times. The research finds that at the Sn/Ru interface, during 300°C reflow for 24 hours, the RU 3 Sn 7 intermetallic compound was formed. As the reflow time increases, the IMC thickness increases. This study provides a fundamental understanding of the interfacial reactions between Sn and Ru. The mechanisms of the interfacial reactions and the growth kinetics of the intermetallic compounds (IMC) will be revealed through phase diagrams, thermodynamics, and kinetic analysis.

关键词： Thermodynamics Ruthenium Tin Atoms Kinetic theory Intermetallic Compounds Microstructure Substrates Electronics packaging

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Production of cobalt- and manganese-based oxide nanofibers via solution blow spinning: Structural properties and high-performance oxygen evolution reaction

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Applied Surface science 2025年 703卷

作者： Pereira, Thiago O. Raimundo, Rafael A. Alves, Ricardo F. Morales, Marco A. Simões, Thiago A. Medeiros, Eliton S. Macedo, Daniel A. Dutra, Ricardo P.S. Materials Science and Engineering Postgraduate Program Federal University of Paraíba PB João Pessoa58051-900 Brazil TEMA – Centre for Mechanical Technology and Automation Department of Mechanical Engineering University of Aveiro Aveiro3810-193 Portugal Department of Mechanical Engineering Federal University of Paraíba PB João Pessoa58051-900 Brazil Department of Theoretical and Experimental Physics Federal University of Rio Grande do Norte Natal59078-970 Brazil Cabo de Santo Agostinho PE 54518-430 Brazil Department of Materials Engineering Federal University of Paraíba PB João Pessoa58051-900 Brazil

Cobalt- and manganese-based oxides (Co3O4, MnCo2O4, and CoMn2O4) with nanofiber-like morphology were successfully synthesized via solution blow spinning (SBS) and evaluated as electrocatalysts for the oxygen evolution reaction (OER). The structural, morphological, and surface properties of the prepared materials were investigated through x-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Fourier-transform infrared (FTIR), Raman spectroscopy, x-ray photoelectron spectra (XPS), and magnetic measurements. The magnetic characterization of MnCo2O4, CoMn2O4, and Co3O4 confirmed their phase purity and expected magnetic behavior. MnCo2O4 exhibited ferromagnetic ordering (θ = +145 K) with Hc = 8200 Oe and Ms = 11.9 emu/g at 5 K. CoMn2O4 showed multiple transitions at 178 K, 169 K, and 81 K, suggesting ferrimagnetic ordering. Co3O4 displayed antiferromagnetic behavior with a Néel temperature of 37 K. These results corroborate with the literature, validating the synthesis and characterization. X-ray photoelectron spectroscopy (XPS) analysis confirmed the oxidation states of Co and Mn and the presence of oxygen vacancies in CoMn2O4, MnCo2O4, and Co3O4. The Oads/Olats ratio indicated a higher concentration of oxygen vacancies in CoMn2O4 (1.21), while MnCo2O4 exhibited the highest Mn4+ content (Mn4+/Mn3+ = 0.76). The Co3+/Co2+ ratio was higher in MnCo2O4 (1.94), suggesting enhanced oxidation stability. The electrochemical characterization for OER in 1 M KOH electrolyte of the CoMn2O4, MnCo2O4, and Co3O4 samples displayed overpotentials of 330, 348, and 375 mV, respectively, to achieve a current density of 10 mA cm−2. Cyclic voltammetry and electrochemical impedance spectroscopy further corroborate these findings. The electrodes exhibited great stability maintaining their performance for 20 h. A detailed surface chemistry analysis showed that oxygen vacancy-rich samples exhibited enhanced charge transfer and generated Mn catalytic sites that facilitated

关键词： Fourier transform infrared spectroscopy

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Dual-compressed photoacoustic single-pixel imaging

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National science Review 2023年第1期10卷 187-195页

作者： Yuning Guo Baowen Li Xiaobo Yin Department of Mechanical Engineering University of Colorado Department of Material Science and Engineering Department of Physics Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Materials Science and Engineering Program University of Colorado

Photoacoustic imaging,an acoustic imaging modality with potentially optical resolution in an optical turbid medium,has attracted great ***,the convergence of wavefront optimization and raster scanning in computational photoacoustic imaging leads to the challenge of fast mapping,especially for a spatial resolution approaching the acoustic deep-subwavelength *** a sparse sampling paradigm,compressive sensing has been applied in numerous fields to accelerate data acquisition without significant quality *** this work,we propose a dual-compressed approach for photoacoustic surface tomography that enables high-efficiency imaging with 3D spatial resolution unlimited by the acoustics in a turbid *** dual-compressed photoacoustic imaging with single-pixel detection,enabled by spatially optical modulation with synchronized temporally photoacoustic coding,allows decoding of the fine optical information from the modulated acoustic signal even when the variance of original photoacoustic signals is *** perform a proof-of-principle numerical demonstration of dual-compressed photoacoustic imaging, that resolves acoustic sub-acoustic-wavelength details with a significantly reduced number of measurements,revealing the potential for dynamic *** dual-compressed concept,which transforms unobtrusive spatial difference into spatio-temporal detectable information,can be generalized to other imaging modalities to re alize efficient,high-spatial-resolution imaging.

关键词： photoacoustic imaging compressive sensing single-pixel imaging surface tomography

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A GENERAL APPROACH TO DETERMINING THE EVOLUTION OF MOLECULAR WEIGHT DISTRIBUTION CURVES OF LINEAR POLYMERS UNDERGOING CHAIN SCISSION

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Chinese Journal of Polymer science 2013年第7期31卷 1056-1060页

作者： Zhuo-li Lin Jun Luo Zheng-jian Chen Ke-hua Tu 王利群王衍伟 MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang University Department of Polymer Science and Engineering College of ChemistryChemical Engineering and Materials ScienceSoochow University

A numerical method is developed to compute the development of molecular weight distribution （MWD） curves of linear polymers undergoing chain scission. The method can be applied to complex chain scission kinetics and for arbitrarily complex initial MWD curves. Our method is based on the method of lines （MoL）. Different from the existing numerical scheme, we propose the use of logarithmically spaced points. This development ensures the accuracy of the computed MWD curves at low molecular weights, and it does not require a very fine discretization to produce an accurate result.

关键词： Polymer degradation Reaction kinetics Molecular weight distribution Modeling.

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Formation of Oxygen Vacancies in Cr³⁺-Doped Hydroxyapatite Nanofibers and Their Role in Generating Paramagnetism

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Biomedical materials and Devices 2025年第1期3卷 529-544页

作者： Carrera, Karime Huerta, Verónica Orozco, Victor Matutes, José Urbieta, Ana Fernández, Paloma Martínez, Fabián Graeve, Olivia A. Herrera, Manuel Centro de Nanociencias y Nanotecnología Universidad Nacional Autónoma de México BC Ensenada C.P. 22800 Mexico Centro de Investigación en Materiales Avanzados Chih. Chihuahua C.P. 31136 Mexico Departamento de Física de Materiales Universidad Complutense de Madrid Madrid C.P. 28040 Spain Program in Materials Science and Engineering University of California San Diego La Jolla 92093-0411 CA United States Department of Mechanical and Aerospace Engineering University of California San Diego La Jolla 92093-0411 CA United States

We demonstrate that doping hydroxyapatite (HAp) with Cr3+ ions induces oxygen vacancies, contributing to paramagnetism. Cathodoluminescence and photoluminescence analyses reveal increased oxygen vacancy formation in O... 详细信息

We demonstrate that doping hydroxyapatite (HAp) with Cr³⁺ ions induces oxygen vacancies, contributing to paramagnetism. Cathodoluminescence and photoluminescence analyses reveal increased oxygen vacancy formation in OH- and PO43- groups with rising Cr³⁺ concentrations, highlighted by stronger cathodoluminescence emissions at 2.57 and 2.95 eV and the photoluminescence emission at 3.32 eV. Raman spectroscopy shows new modes at 900 and 970 cm⁻¹, indicating distortion of the v₁ vibrational mode due to Cr³⁺ substitution at Ca(II) sites of the HAp lattice. X-ray photoelectron spectroscopy confirms Cr³⁺ in the HAp:Cr. Magnetometry reveals a shift from diamagnetism in pure HAp to increasing paramagnetism in HAp:Cr with higher Cr³⁺ content, achieving 0.0460 emu/g at 10 kOe with concentrations higher than 2.9 at.%. This paramagnetism is attributed to Cr³⁺ ions and singly ionized oxygen vacancies VO′ aligning along an external magnetic field, with VO′ formation linked to PO43- replacement by PO32- in HAp. © The Author(s) 2024.

关键词： Cathodoluminescence Cr3+ Hydroxyapatite Oxygen vacancies Paramagnetism

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Bioprinted high cell density liver model with improved hepatic metabolic functions

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Biomaterials 2025年 320卷 123256-123256页

作者： Lu, Ting-Yu Ji, Yichun Lyu, Cheng Shen, Erin Nicole Sun, Yazhi Xiang, Yi Meng-Saccoccio, Tobias Feng, Gen-Sheng Chen, Shaochen Program in Materials Science and Engineering University of California San Diego La Jolla CA92093 United States Department of Pathology Department of Molecular Biology Moores Cancer Center University of California San Diego La Jolla CA92093 United States Department of Chemical and Nano Engineering University of California San Diego La Jolla CA92093 United States Department of Bioengineering University of California San Diego La Jolla CA92093 United States

In vitro liver tissue models are valuable for studying liver function, understanding liver diseases, and screening candidate drugs for toxicity and efficacy. While three-dimensional (3D) bioprinting shows promise in creating various types of functional tissues, current efforts to engineer a functional liver tissue face challenges in replicating native high cell density (HCD) and maintaining long-term cell viability. HCD is crucial for establishing the cell-cell interactions necessary to mimic the liver's metabolic and detoxification functions. However, HCD bioinks exacerbate light scattering in light-based 3D bioprinting. In this study, we incorporated iodixanol into our bioink formulation to minimize light scattering, enabling the fabrication of hepatic tissue constructs with an HCD of 8 × 107 cells/mL while maintaining high cell viability (∼80 %). The printed dense hepatic tissue constructs showed enhanced cell-cell interactions, as evidenced by increased expression of E-cadherin and ZO-1. Furthermore, these constructs promoted albumin secretion, urea production, and P450 metabolic activity. Additionally, HCD hepatic tissue inactivated the YAP/TAZ pathway via cell-cell interactions, preserving primary hepatocyte functions. Further screening revealed that hepatocytes in the dense model were more sensitive to drug treatments than those in a lower-density hepatic model, highlighting the importance of HCD in recapitulating the physiological drug responses. Overall, our approach represents a significant advancement in liver tissue engineering, providing a promising platform for the development of physiologically relevant in vitro liver models for drug screening and toxicity testing. © 2025 Elsevier Ltd

关键词： 3D bioprinting in vitro hepatic model primary hepatocyte high cell density drug screening

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Meter-scale heterostructure printing for high-toughness fiber electrodes in intelligent digital apparel

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Nature Communications 2025年第1期16卷 1-10页

作者： Lee, Gun-Hee Lee, Yunheum Seo, Hyeonyeob Jo, Kyunghyun Yeo, Jinwook Kim, Semin Bae, Jae-Young Kim, Chul Majidi, Carmel Kang, Jiheong Kang, Seung-Kyun Ryu, Seunghwa Park, Seongjun Medical Research Center Seoul National University Seoul South Korea Departments of Cogno-Mechatronics Engineering and Optics & Mechatronics Engineering Pusan National University Busan South Korea Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon South Korea Program of Brain and Cognitive Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon South Korea Department of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon South Korea Graduate School of Semiconductor Technology Korea Advanced Institute of Science and Technology (KAIST) Daejeon South Korea Department of Materials Science and Engineering Seoul National University Seoul South Korea Department of Mechanical Engineering Carnegie Mellon University Pittsburgh PA United States Department of Chemistry Seoul National University Seoul Seoul South Korea School of Transdisciplinary Innovations Seoul National University Seoul South Korea Department of Biomedical Science College of Medicine Seoul National University Seoul South Korea Interdisciplinary Program in Bioengineering College of Engineering Seoul National University Seoul South Korea Department of Transdisciplinary Medicine Seoul National University Hospital Seoul South Korea

Intelligent digital apparel, which integrates electronic functionalities into clothing, represents the future of healthcare and ubiquitous control in wearable devices. Realizing such apparel necessitates developing meter-scale conductive fibers with high toughness, conductivity, stable conductance under deformation, and mechanical durability. In this study, we present a heterostructure printing method capable of producing meter-scale (~50 m) biphasic conductive fibers that meet these criteria. Our approach involves encapsulating deformable liquid metal particles (LMPs) within a functionalized thermoplastic polyurethane matrix. This encapsulation induces in situ assembly of LMPs during fiber formation, creating a heterostructure that seamlessly integrates the matrix’s durability with the LMPs’ superior electrical performance. Unlike rigid conductive materials, deformable LMPs offer stretchability and toughness with a low gauge factor. Through precise twisting using an engineered annealing machine, multiple fiber strands are transformed into robust, electrically stable meter-scale electrodes. This advancement enhances their practicality in various intelligent digital apparel applications, such as stretchable displays, wearable healthcare systems, and digital controls. © The Author(s) 2025.

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Thermally Activated Delayed Fluorescence-Guided Photodynamic Therapy Through Skeleton-Homologous Nanoparticles: a Rational Material Design for High-Efficient and High-Contrast Theranostics

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Advanced materials 2025年 e2500236页

作者： Li, Xuping Huang, Liwen Baryshnikov, Gleb Ali, Amjad Dai, Peiling Yang, Zhongxue Sun, Yuyu Dai, Chunling Guo, Zhixiu Zhao, Qiang Zhang, Fan Zhu, Liangliang College of Energy Materials and Chemistry Inner Mongolia University Hohhot010070 China Department of Chemistry State Key Laboratory of Molecular Engineering of Polymers Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials and iChem Fudan University Shanghai200033 China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University Shanghai200033 China Laboratory of Organic Electronics Department of Science and Technology Linköping University NorrköpingSE-601 74 Sweden Nanjing University of Posts & Telecommunications Nanjing210023 China

Although photoluminescence imaging-guided photodynamic therapy (PDT) is promising for theranostics, it easily suffers from tissue autofluorescence and PDT photoproducts. To develop time-resolved imaging (TRI)-guided PDT with long-lived emission pathways, like thermally activated delayed fluorescence (TADF), is urgent but challenging, because of the triplet competition between radiative transition and reactive oxygen species (ROS) production. Herein, skeleton-homologous nanoparticles are designed and constructed to address this dilemma, thereby achieving in vivo TRI-guided PDT for the first time. This system is formed with a lipophilic TADF core (as a TRI probe) encapsulated by an amphiphilic photosensitizer shell (as the corona exposed to oxygen for PDT), both of which are derived from the same donor–acceptor skeleton to minimize phase separation in the single entity, and enable the same long-wavelength photoexcitation for TRI and PDT. The chloropropylamine group is helpful for endoplasmic reticulum targeting to enhance PDT upon minimizing the ROS transmission path. Synchronously, the TADF core exhibits a delayed fluorescence of 40 µs for a clear TRI. The NPs are eventually applied in vivo with a high signal-to-background ratio (45.25) and outstanding PDT effects in a mouse model of deep-seated kidney cancer. Such a material design is beneficial for developing high-efficient and high-contrast theranostic approaches. © 2025 Wiley-VCH GmbH.

关键词： Musculoskeletal system

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