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Understanding the reactivity of H2 is of critical importance in controlling and optimizing many heterogeneous catalytic processes, particularly in cases where its adsorption on the catalyst surface is rate-limiting. In this work, we examine the temperature-dependent adsorption of H2/D2 on the clean RuO2(110) surface using the King and Wells molecular beam approach, temperature-programmed desorption (TPD), and scanning tunneling microscopy (STM). We show that the adsorption probability of H2/D2 on this surface is highly temperature-dependent, decreasing from ∼0.4 below 25 K to <0.01 at 300 K. Both STM and TPD reveal that adsorption (molecular or dissociative) is severely limited once the temperature exceeds the trailing edge temperature of the H2 TPD state (∼150 K). The presence of coadsorbed water or oxygen does not appear to alter this situation. Previous literature reports of extensive RuO2(110) surface hydroxylation from H2/D2 exposures at 300 K may instead be the result of background contamination brought about by chamber backfilling.
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http://dx.doi.org/10.1021/acs.jpclett.6b01307 | DOI Listing |
J Comput Chem
September 2025
Department of Electrical and Electronic Engineering, Begum Rokeya University, Rangpur, Bangladesh.
This study presents a comprehensive first-principles and device-performance investigation of alkali metal-based anti-perovskites ZBrO (Z = K, Rb, Cs, and Fr) for advanced optoelectronic and photovoltaic applications. Using density functional theory (DFT) with GGA-PBE and mGGA-rSCAN functionals, we analyzed the structural, electronic, optical, mechanical, phonon, population, and thermoelectric properties of these compounds. All ZBrO materials exhibit direct band gaps and strong optical absorption in the visible-UV spectrum.
View Article and Find Full Text PDFJ Sep Sci
September 2025
Programa De Pós-Graduação em Química, Universidade Federal de Sergipe, São Cristóvão, Sergipe, Brazil.
Secondary metabolites are important bioactive compounds for diet and medicine. This study optimizes the extraction of hydroethanolic herbal extracts using an EDGE (Energized Dispersive Guided Extraction) system, evaluates their antioxidant capacity, and analyzes correlations among antioxidant activity, total phenolic content, and individual compounds. A Doehlert matrix design was used to optimize extraction, having temperature and time as independent variables, and total phenolic content (mg GAE/g) as the response, quantified via the Folin-Ciocalteu method.
View Article and Find Full Text PDFJ Affect Disord
September 2025
Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA; Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA; Department of Neurology, Yale University, New Haven, CT, USA. Electronic address:
Purpose: Dopamine is a neurotransmitter implicated in functions ranging from motor control to cognitive performance. In humans, dopaminergic markers have been associated with seasonal symptomatic fluctuations. Here we investigated potential seasonal variations in dopamine D2/D3 receptor availability in healthy adults using [C]PHNO positron emission tomography (PET) imaging.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2025
State Key Laboratory of Advanced Fiber Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China. Electronic address:
Polyimide (PI) faces significant challenges in highly integrated and high-frequency electronic devices due to its inherently low thermal conductivity and relatively high dielectric constant (D). In this study, topologically micro-crosslinked PI films were synthesized by incorporating highly conjugated multi-amino polydiacetylene (MAPDA) into a fluorinated PI matrix. The unique alkene-alkyne alternating conjugated structure of MAPDA, combined with the strong electron-withdrawing trifluoromethyl groups in the matrix, promotes charge redistribution and reduces the dipole moment and polarizability.
View Article and Find Full Text PDFPlant Physiol Biochem
September 2025
State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, People's Republic of China. Electronic address:
As global climate change intensifies heat stress and threatens food security, exploring and utilizing valuable genetic resources are crucial for crop improvement. Zygophyllum xanthoxylum, a xerophyte adapted to extreme desert conditions, is a valuable model for excavating thermotolerance genes. This species exhibits differential expression of numerous WRKY genes under heat treatments.
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