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Povrchové napětí a stavové veličiny látek
Jůza, Josef
Příspěvek ukazuje úpravu některých dobře známých rovnic vyjadřujících povrchové napětí pomocí stavových veličin a jiných parametrů tak, aby vyjadřovaly poměr povrchového napětí k hustotě, který je primárnějším výsledkem měření povrchového napětí metodou visící kapky a je dostupný i když není známa hustota.
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Impact of weathering on chemical and morphological changes in stabilized polymers
Pospíšil, Jan ; Pilař, Jan ; Billingham, N. C. ; Marek, Antonín ; Kruliš, Zdeněk ; Nešpůrek, Stanislav ; Habicher, W. D.
Photooxidation, considered as the principal component of natural and accelerated weathering, affects together with oxygen,oxidizing and acid atmospheric pollutants durability of stabilized polymers by changing their chemical and supramolecular structure and influencing efficiency of stabilizers. Effects of the harshness of accelerated photooxidation, negative influences of atmospheric pollutants, heterogeneity in polymer oxidation together with formation of concentration gradients in stabilizer consumption and spatial distribution of stabilizer sacrificial transformation products are outlined. The data give more information on processes accompanying testing of stabilizer polymers and help to minimize misleading influences from over-accelerated tests.
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Molecular current switch
Nešpůrek, Stanislav ; Sworakowski, J.
Scheme of an optically controlled current switch is put forward, based on properties of a conducting polymer containing photochromic moieties chemically attached to the main chain. The idea is supported with results of calculations of local states for charge carriers formed in the vicinity of dipolar species in molecular materials, and with measurements of the drift mobilities in polysilane copolymers containing polar benzaldehyde 2,4-dinitrophenyl-hydrazone groups.
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