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Kokol Vanja Vivod Vera Peršin Zdenka Čolić Miodrag Kolar Matjaž 《Cellulose (London, England)》2021,28(10):6545-6565
Cellulose - Bio-based, renewable and biodegradable products with multifunctional properties are also becoming basic trends in the textile sector. In this frame, cellulose nanofibrils (CNFs) have... 相似文献
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This study confirms the enzyme-mediated phosphorylation of cellulose nanofibers (CNF) by using hexokinase and adenosine-5′-triphosphate in the presence of Mg-ions, resulting in a phosphate group’s creation predominantly at C-6-O positioned hydroxyl groups of cellulose monomer rings. A proof-of-concept is provided using 12C CPMAS, 31P MAS nuclear magnetic resonance, attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy (XPS) analyzing methods. The degree of substitution (DS) is determined by elemental analysis and compared to DS estimated by XPS analysis. From the thermal degradation measurements using thermo-gravimetric analysis, the C-6-O phosphorylation was found to noticeably prevent the CNF derivatives from weight loss in the pyrolysis process, thus, providing them flame-resistance functionality. Furthermore, phosphorylation significantly enhanced adsorption capacity of Fe3+ ions making them interesting for fabrication of biobased filters and membranes. Finally, the biomimetic growth of Ca–P crystals (hydroxyapatite) in simulated body fluid was characterized by scanning electron microscopy and energy dispersive X-ray, showing potential application as biomedical materials. 相似文献
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Vanja Margetic Ticijana Ban Ota Samek Franz Leis Kay Niemax Roland Hergenröder 《Czechoslovak Journal of Physics》2004,54(4):423-429
Fluorescence measurements have been used to characterize the velocity of atoms in a femtosecond-laser-produced plasma. Nanogram
amounts of a copper sample were ablated by the focused radiation (λ=775 nm) of an all-solid-state laser. The laser was operated
at a pulse rate of 10 Hz with an energy of 200μJ per pulse. The microplasma expanded into a defined argon atmosphere of pressures between 0.02 and 850 mbar. Atomic fluorescence
was excited in the laser plume by a dye-laser pulse with the wavelength set to the line Cu I 282.4 nm. The narrowed beam of
the dye-laser was directed into the plasma at different heights above the sample surface. The fluorescence radiation was measured
with an échelle-spectrometer, equipped with an intensified-charge-coupled device as the detector. The velocity depends strongly
on the pressure of the ambient atmosphere and the distance from the sample surface. The highest velocity found at an argon
pressure of 0.02 mbar was 1.0×106 cm s−1. 相似文献
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Protein–protein conjugates formed by carbodiimide crosslinking reactions have been analyzed for the first time using CE. Lysozyme and BSA were chosen as model proteins to study the efficacy of N‐(3‐dimethylaminopropyl)‐N‐ethylcarbodiimide and N‐hydroxysuccinimide as crosslinkers. Detection of the molecular mass increase was checked by SDS‐PAGE. Commercially available, PVA‐coated capillaries showed appropriate selection, while phospho‐deactivated and dynamic PVA‐coated capillaries did not give suitable resolution. CE was found to be an efficient tool to characterize homo‐ (lysozyme–lysozyme) and hetero‐ (lysozyme–BSA) protein coupling by suitable variations of electrophoretic mobilities. 相似文献
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Damjana Kokol Bukovšek 《Linear algebra and its applications》2007,420(1):34-50
We study non-degenerate irreducible homomorphisms from the multiplicative semigroup of all n-by-n matrices over an algebraically closed field of characteristic zero to the semigroup of m-by-m matrices over the same field. We prove that every non-degenerate homomorphism from the multiplicative semigroup of all n-by-n matrices to the semigroup of (n + 1)-by-(n + 1) matrices when n ? 3 is reducible and that every non-degenerate homomorphism from the multiplicative semigroup of all 3-by-3 matrices to the semigroup of 5-by-5 matrices is reducible. 相似文献
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Karin Cvetko-Vah Damjana Kokol Bukov?ek Toma? Ko?ir Ganna Kudryavtseva 《Acta Mathematica Hungarica》2011,131(1-2):1-24
We prove that the minimal cardinality of a semitransitive subsemigroup in the singular part $\mathcal{I}_{n}\setminus \mathcal{S}_{n}$ of the symmetric inverse semigroup $\mathcal{I}_{n}$ is 2n?p+1, where p is the greatest proper divisor of n, and classify all semitransitive subsemigroups of this minimal cardinality. 相似文献
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Vanja Calija Andrew J. Higgins Phillip A. Jackson Leone M. Bielig Danny Coomans 《Annals of Operations Research》2001,108(1-4):123-142
Selection for superior clones is the most important aspect of sugar cane improvement programs, and is a long and expensive process. While studies have investigated different components of selection independently, there has not been a whole system approach to improve the process. This study observes the problem as an integrated system, where if one parameter changes the state of the whole system changes. A computer based stochastic simulation model that accurately represents the selection was developed. This paper describes the simulation model, showing its accuracy as well as how a combination of dynamic programming and branch and bound can be applied to the model to optimise the selection system, giving a new application of these techniques. The model can be directly applied to any region targeted by sugarcane breeding programs or to other clonally propagated crops. 相似文献
9.
Kolar Tjaša Mušič Branka Korošec Romana Cerc Kokol Vanja 《Cellulose (London, England)》2021,28(14):9441-9460
Cellulose - Differently structured aluminum (tri/mono) hydroxide (Al(OH)3 /AlO(OH)) nanoparticles were prepared and used as thermal-management additives to microfibrillated cellulose (MFC),... 相似文献
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