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471.
Tamara A. Bazhenova Vyacheslav A. Kopotkov Denis V. Korchagin Yuriy V. Manakin Leokadiya V. Zorina Sergey V. Simonov Ilya A. Yakushev Vladimir S. Mironov Alexander N. Vasiliev Olga V. Maximova Eduard B. Yagubskii 《Molecules (Basel, Switzerland)》2021,26(22)
A series of six seven-coordinate pentagonal-bipyramidal (PBP) erbium complexes, with acyclic pentadentate [N3O2] Schiff-base ligands, 2,6-diacetylpyridine bis-(4-methoxybenzoylhydrazone) [H2DAPMBH], or 2,6-diacethylpyridine bis(salicylhydrazone) [H4DAPS], and various apical ligands in different charge states were synthesized: [Er(DAPMBH)(C2H5OH)Cl] (1); [Er(DAPMBH)(H2O)Cl]·2C2H5OH (2); [Er(DAPMBH)(CH3OH)Cl] (3); [Er(DAPMBH)(CH3OH)(N3)] (4); [(Et3H)N]+[Er(H2DAPS)Cl2]− (5); and [(Et3H)N]+[Y0.95Er0.05(H2DAPS)Cl2]− (6). The physicochemical properties, crystal structures, and the DC and AC magnetic properties of 1–6 were studied. The AC magnetic measurements revealed that most of Compounds 1–6 are field-induced single-molecule magnets, with estimated magnetization energy barriers, Ueff ≈ 16–28 K. The experimental study of the magnetic properties was complemented by theoretical analysis based on ab initio and crystal field calculations. An experimental and theoretical study of the magnetism of 1–6 shows the subtle impact of the type and charge state of the axial ligands on the SMM properties of these complexes. 相似文献
472.
Yana Shymborska Prof. Andrzej Budkowski Prof. Joanna Raczkowska Prof. Volodymyr Donchak Yuriy Melnyk Dr. Viktor Vasiichuk Prof. Yurij Stetsyshyn 《Chemical record (New York, N.Y.)》2024,24(2):e202300217
Responsive polymer systems have the ability to change properties or behavior in response to external stimuli. The properties of responsive polymer systems can be fine-tuned by adjusting the stimuli, enabling tailored responses for specific applications. These systems have applications in drug delivery, biosensors, tissue engineering, and more, as their ability to adapt and respond to dynamic environments leads to improved performance. However, challenges such as synthesis complexity, sensitivity limitations, and manufacturing issues need to be addressed for successful implementation. In our review, we provide a comprehensive summary on stimuli-responsive polymer systems, delving into the intricacies of their mechanisms and actions. Future developments should focus on precision medicine, multifunctionality, reversibility, bioinspired designs, and integration with advanced technologies, driving the dynamic growth of sensitive polymer systems in biomedical applications. 相似文献
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Yuriy Azhniuk Vasyl Lopushansky Stepan Hasynets Volodymyr Kryshenik Alexander V. Gomonnai Dietrich R. T. Zahn 《Journal of Raman spectroscopy : JRS》2024,55(5):637-649
Raman spectra of (As1–xBix)2S3 glass samples with x ≤ 0.2 measured at the excitation with above-bandgap (532 nm) laser light at a relatively low power density (Pexc = 4 kW/cm2) clearly confirm the amorphous character, thereby markedly extending the known compositional interval of existence of the (As1–xBix)2S3 glass previously known (x ≤ 0.06). Spectra measured at an increased Pexc (40 kW/cm2) reveal a photostructural transformation in the illuminated area of the glass leading to an additional contribution of Bi–S bonds as well as to an increasing number of cage-type As4S4 units with homopolar As–As bonds. A number of new features in a broad range up to about 1,000 cm−1, which emerge in the Raman spectra of the (As1–xBix)2S3 glasses with high (x ≥ 0.14) Bi content and increase in intensity with the exposure time, are related to a photochemical transformation, namely, oxidation of arsenic and sulphur on the (As1–xBix)2S3 glass surface with formation of units containing arsenate AsO43− and sulphate SO42− ions. These processes are irreversible and occur only in the presence of a sufficient amount of bismuth. 相似文献
475.
Georgiy V. Malkov Alexey V. Shastin Yakov I. Estrin Elmira R. Badamshina Yuriy M. Mikhailov 《Macromolecular Symposia》2010,296(1):107-111
The results of the kinetic study of melt and solution polymerization at the 1,3-dipolar cycloaddition reaction of the AB2 monomer – 2-azido-4,6-bis(prop-2-yn-1-yloxy)-[1,3,5]-triazine (ABPOT) are presented in this work as well as the results of the 13C-NMR characterization of the obtained hyperbranched poly([1,2,3]-triazole-[1,3,5]-triazine)s. It is established, that the first-shell substitution effect during polyaddition process and unusual high degree of branching (up to 0.9) of polymers synthesized in melt are held. 相似文献
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Carbon/carbon (C/C) composites are widely represented in the industry and are utilized for extreme thermal and mechanical loading. Optimization of the fibers distribution allows by still high stiffness to provide reducing of the weight of the components that has crucial importance in aircraft and aerospace industry. A microstructure optimization problem for estimation of the microstructure with minimal compliance is formulated. The design variables of the posed problem are the local fibers distribution and porosity. The volume fractions of the fibers and pores in the whole microstructure are fixed. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献