Results 21 to 30 of about 5,175 (154)

PINTURAS RUPESTRES DO SÍTIO ARQUEOLÓGICO LETREIRO DA PEDRA RISCADA: Micromorfologia, Composição Química e Espécies Ferruginosas dos Filmes Pictóricos

Clio Arqueológica, 2020
Neste trabalho, a composição química e espécies ferruginosas de filmes pictóricos de pinturas rupestres do sítio arqueológico Letreiro da Pedra Riscada (Domingos Mourão, Piauí, Brasil) foram investigadas por fluorescência de raios X e espectroscopia ...
José de Jesus Nunes Júnior, Luis Carlos Duarte Cavalcante   +1 more
doaj   +1 more source

Modulating Local Coordination in Single‐Atom Catalysts: From Fundamental Concepts to Emerging Breakthroughs in Electrocatalysis

Angewandte Chemie, EarlyView.
This review summarizes atomic‐level design strategies for single‐atom catalysts, emphasizing modulation of the local coordination environment, active‐site geometry, and metal‐support interactions to optimize catalytic activity and stability in electrocatalytic energy conversion applications.
Ashwani Kumar, Harun Tüysüz
wiley   +2 more sources

Coupled Fe3O4‐Cluster Precipitates and Single Fe‐Atom Catalysts Can Boost Oxygen Reduction via Concomitantly Accelerated Water Dissociation

Angewandte Chemie, EarlyView.
Fe3O4 clusters can be precipitated onto Fe–N–C SACs through a residual‐oxygen‐assisted precipitation approach. Compelling evidence, including operando spectroscopy and ab initio calculations, suggests that Fe3O4‐cluster precipitates not only induce asymmetric electronic structures of Fe‐N4 active center to optimize the OH* adsorption, but also ...
Cheng‐Kai Du, Xiongyi Liang, Fei‐Xiang Ma, Yutong Li, Zheng‐Qi Liu, Long Ma, Zeng Li, Liang Zhen, Yan Huang, Xiao Cheng Zeng, Cheng‐Yan Xu   +10 more
wiley   +2 more sources

Mössbauer Spectroscopy as a Valuable Analysis Technique in Biomedical Research

CHIMIA
Mössbauer spectroscopy is an effective technique used to examine the iron atom electronic environments in both biomolecular molecules and whole animal studies. Because of its sensitivity to nuclear hyperfine interactions, this technique yields incredibly
Jasim Hassen, Jack Silver
doaj   +1 more source

Study of the Effect of Quenching on Microstructural and Magnetic Properties of Cu-Doped Mg-Ferrite

Advances in Condensed Matter Physics, 2022
Mg1-xCuxFe2O4 (x = 0.0–0.5) was prepared by the double sintering ceramic method, which sintered at 1100°C and 1200°C for 3 hours and investigated for structural, microstructural, and magnetic properties as a function of the Cu content and cooling process.
Apurba Poddar, Suman Halder, S.I. Liba, Sheikh Manjura Hoque, Shibendra Shekher Sikder   +4 more
doaj   +1 more source

Tailoring High‐Valent Iron‐Oxo Species Redox via Extended π‐Fe3d–O2p Orbital Overlapping Toward Chemical‐Efficient Water Purification

Angewandte Chemie, EarlyView.
We address the long‐standing challenge of reactivity–selectivity trade‐off by precisely tuning the redox properties of Fe(IV), rather than simply accelerating its formation, to enable chemically efficient and low‐emission water treatment. ABSTRACT High‐valent iron oxo species (Fe(IV)) are attractive for wastewater treatment because of their high ...
Hongyu Zhou, Junwen Chen, Jiuyi Wang, Xinhao Wang, Qiming Zhang, Shiying Ren, Xuning Li, Li Gao, Shaobin Wang, Xiaoguang Duan   +9 more
wiley   +2 more sources

57Fe Mössbauer spectroscopy investigation of La0.7Ca0.3Mn0.5Fe0.5O3

Results in Physics, 2016
A La0.7Ca0.3Mn0.5Fe0.5O3 (LCMFO) ceramic sample was produced using conventional solid-state reactions. According to the X-ray diffraction data, the obtained sample has an orthorhombic space group Pnma (a = 5.482(2) Å, b = 7.739(3) Å, c = 5.446(3) Å ...
V.S. Zakhvalinskii, E.A. Piliuk, S.V. Taran, A. Sklyarova, V.V. Matveev, J. Lindén, I. Zakharchuk   +6 more
doaj   +1 more source

Recent Advances in Ferrite‐Based Materials for Biomedical Applications: A Comprehensive Review

Advanced Materials, EarlyView.
Ferrite nanoplatforms are presented as tunable biomedical materials in which synthesis control, cation engineering, defect/morphology regulation, and surface functionalization govern structure–property–bioactivity relationships. These design strategies enable multifunctional applications including MRI contrast, magnetic hyperthermia, targeted drug ...
Pramod D. Mhase, Varsha C. Pujari, Akash V. Fulari, Sunil M. Patange, Sean Li, Danyang Wang, Sagar E. Shirsath   +6 more
wiley   +1 more source

Escaping the Scaling Relationships in Oxygen Reduction Catalysis: Implications for PEM Fuel Cells

Advanced Materials, EarlyView.
Escaping the scaling relationships of the oxygen reduction reaction is vital for hydrogen fuel cells. This outlook examines how interfacial heterogeneity, spanning the subsurface lattice, chemisorption layer, and near‐interface solvation volume, mechanistically decouples intermediate binding energetics.
Muhammad Bilal Wazir, Lourdes F. Vega, Maryam Khaleel   +2 more
wiley   +1 more source

Novel neutral iron(II) isocyanide maleonitrile dithiolate [Fe(S2C2(CN)2)(t-BuNC) 4] compound

Química Nova, 2004
FeBr2 reacts with the S2C2(CN)2(2-) ion (1:1 ratio) in the presence of an excess of t-BuNC in THF to give the mixed ligand [Fe(S2C2(CN)2)(t-BuNC) 4] compound.
Milton K. Morigaki, Elias M. da Silva, Carlos V. P. de Melo, Carlos Larica, Armando Biondo, Jair C. C. Freitas, Gilson H. M. Dias, Holgadinei R. Ribeiro   +7 more
doaj   +1 more source