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31.
Mehrdad Hesampour Tiina Huuhilo Katri Mkinen Mika Mnttri Marianne Nystrm 《Journal of membrane science》2008,310(1-2):85-92
Poly(N-isopropyl acrylamide) (PNIPAAm) was grafted on a polysulfone UF membrane. The changes of permeability as well as retention of PEG (35 kg/mol) and Dextran (500 kg/mol) between 23 and 60 °C were determined for both grafted and unmodified membranes. The results showed that the viscosity corrected water permeability and solute retention were almost constant for the unmodified membranes within the measured temperature range, the permeability of the grafted membranes increased and the retention of Dextran and PEG decreased with temperature. The variation of changes was most obvious in the temperature range 27–37 °C for the modified membranes due to the lower critical solution temperature (LCST) of PNIPAAm. The location and profile of PNIPAAm inside and on the surface of the membrane were analysed by SEM and FTIR. Depth profile calculation for FTIR spectra showed that PNIPAAm was mostly placed inside the membrane (at a depth of 1.06–1.10 μm from the surface) rather than on the surface. The amount of grafted PNIPAAm was low and did not significantly affect the morphology of the membrane. Therefore, a difference in SEM pictures of modified and unmodified membranes could not be seen. The modified membrane exhibited a clearly different thermal response compared to the unmodified one. 相似文献
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Arto Valkonen Katri Laihia Erkki Kolehmainen Reijo Kauppinen Pál Perjési 《Structural chemistry》2012,23(1):209-217
1H and 13C NMR chemical shifts have been determined and assigned based on PFG 1H, 13C HMQC, and HMBC experiments for 3-(4′-X-benzyl)-4-chromenones (Ia, X = CN and Ib, X = NO2), 3-(4′-X-benzyl)-4-thiochromenones (IIa, X = Cl and IIb, X = Br), (E)-3-(4′-X-benzylidene)-4-chromanones (IIIa–IIIe, X = OCH3, CH3, Cl, N(CH3)2, Br), (Z)-3-(4′-X-benzylidene)4-thiochromanones (IVa–IVd, X = Cl, Br, F, OCH3), 2-benzyl-1,2,3,4-tetrahydro-1-naphthol (V), 2-benzyl- and (E)-2-benzylidene-1-tetralones (VI and VII), and (E)-2-benzylidene-1-benzosuberol (VIII). The crystal structures have been determined for the following seven compounds: derivatives of 4-chromanones (IIIa–IIId), 1-tetrahydronaphtol (V), and 1-tetralones (VI and VII). The molecular features and intermolecular interactions in crystal state have been discussed. 相似文献
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Ohne ZusammenfassungDie Autoren haben über diese Arbeit 1969 auf einer Sommerschule in Cikháj (Tschechoslowakei) vorgetragen. Eine Ausarbeitung dieses Vortrages wurde in dem Bericht der Sommerschule gedruckt, der 1969 von der Universität Brno herausgegeben wurde.Alexander von Humboldt-Stipendiat am Mathematischen Institut der Universität Bonn. 相似文献
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Kontturi Katri S. Lee Koon-Yang Jones Mitchell P. Sampson William W. Bismarck Alexander Kontturi Eero 《Cellulose (London, England)》2021,28(10):6619-6628
Cellulose - Cellulose nanopapers provide diverse, strong and lightweight templates prepared entirely from sustainable raw materials, cellulose nanofibers (CNFs). Yet the strength of CNFs has not... 相似文献
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Recently, Gr?tzer, Gunderson and Quackenbush have characterized the spectra of finite pseudocomplemented lattices, solving a problem raised by G. Gr?tzer in his first monograph on lattice theory from 1971. In this note we discuss the tight connection between the spectra and the Glivenko congruence of finite pseudocomplemented lattices. 相似文献
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We derive sum rules for the sparticle masses in different models of supersymmetry breaking. This includes the gravity-mediated
models (SUGRA models) as well as models in which supersymmetry breaking terms are induced by super-Weyl anomaly (AMSB models).
These sum rules can help in distinguishing between these models. In particular, we obtain an upper bound on the mass of the
lightest neutralino as a function of the gluino mass in SUGRA and AMSB models. 相似文献