The singlet excited-state lifetime of a bipyridyl platinum(II) complex containing two alkynyl-benzothiazolylfluorene units was determined to be 145+/-105 ps by fitting femtosecond transient difference absorption data, and the triplet quantum yield was measured to be 0.14. A ground-state absorption cross section of 6.1 x 10(-19) cm(2) at 532 nm was deduced from UV-visible absorption data. Excited-state absorption cross sections of (6.7+/-0.1) x 10(-17) cm(2) (singlet) and (4.6+/-0.1) x 10(-16) cm(2) (triplet) were obtained by using a five-level dynamic model to fit open-aperture Z scans at picosecond and nanosecond pulse widths and a variety of pulse energies. For this complex, the ratio of the triplet excited-state absorption cross section to the ground-state absorption cross section--long used as a figure of merit for reverse saturable absorbers--thus stands at 754, to our knowledge the largest ever reported at 532 nm wavelength.
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http://dx.doi.org/10.1364/OL.35.001305 | DOI Listing |
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January 2025
Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing, 100191, P. R. China.
A reasonable construction of hollow structures to obtain high-performance absorbers is widely studied, but it is still a challenge to select suitable materials to improve the low-frequency attenuation performance. Here, the FeO@C@NiO nanoprisms with unique tip shapes, asymmetric multi-path hollow cavity, and core-shell heteroepitaxy structure are designed and synthesized based on anisotropy and intrinsic physical characteristics. Impressively, by changing the load of NiO, the composites achieve strong absorption, broadband, low-frequency absorption: the reflection loss of -55.
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January 2025
Department of Mechanical and Nuclear Engineering, Khalifa University of Science & Technology, Abu Dhabi, UAE.
This study investigates the quasi-static and dynamic compression performance of a newly designed stacked pyramidal lattice (SPL) structure composed of struts that resemble I-beams. These novel lattice structures are 3D-printed considering three different stacking sequences, and their stiffness, strength, and energy absorption properties are experimentally assessed through low-velocity impact (1.54 m/s) and quasi-static compression tests.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Research Center of Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Ji'nan 250012, China. Electronic address:
Dry socket, a common painful complication after tooth extraction, is typically caused by improper blood clot formation or its premature dislodgement, often exacerbated by bacterial infections. Traditional gelatin sponges, widely used as clinical fillers, provide favorable biocompatibility and hemostatic support but suffer from suboptimal hemostatic efficiency, lack of antimicrobial properties, and insufficient anticoagulant factors, which increase the risk of dry socket. Addressing these limitations, a novel tannic acid cross-linked gelatin sponge has been developed using directional lyophilization.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Physics, Indian Institute of Technology Delhi (IITD), Delhi 110016, India.
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are considered to be the most important processes in metal-air batteries and regenerative fuel cell devices. Metal-organic polymers are attracting interest as promising precursors of advanced metal/carbon electrocatalysts because of their hierarchical porous structure along with the integrated metal-carbon framework. We developed carbon-coated CNTs with Ni/Fe and Cu/Fe as active sites.
View Article and Find Full Text PDFMicrobiome
January 2025
Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot, 010010, China.
Background: While Gangba sheep being well known for their unique flavour and nutritional value, harsh environmental factors negatively affect their growth and development, leading to poor productivity. The gastrointestinal tract microbiota plays an important role in host nutrient absorption and metabolism. The identification of dynamic changes in the gastrointestinal microbial communities and their functions is an important step towards improving animal production performance and health.
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