173,844 research outputs found
Green Synthesis of Zr-CAU-28: Structure and Properties of the First Zr-MOF Based on 2,5-Furandicarboxylic Acid
No full textA new Zr-based metal–organic
framework denoted as Zr-CAU-28 with framework composition [Zr6O4(OH)4(FDC)4(OH)4(H2O)4] (H2FDC = 2,5-furandicarboxylic
acid, CAU = Christian-Albrechts-University) was obtained under green
synthesis conditions from a mixture of H2O and acetic acid
and employing microwave-assisted heating. Zr-CAU-28 is the first Zr-MOF
based on H2FDC, which is often considered a promising renewable
alternative to terephthalic acid. The crystal structure was determined
from powder X-ray diffraction data using a combination of direct methods,
force field calculations, and Rietveld refinement. The compound crystallizes
in the hexagonal crystal system (space group P63/mmc) with the cell parameters a = 24.9919(9) and c = 24.7688(9) Å. The framework
structure adopts a kagome-like topology and hence contains large hexagonal
channels with a pore diameter of approximately 16 Å and small
trigonal channels with a size of 3 Å. Nitrogen sorption measurements
were carried out at −196 °C and gave a specific surface
area of SBET = 1006 m2/g and
a micropore volume of 0.42 cm3/g. Thermogravimetric analyses
showed a stability up to 270 °C although temperature dependent
PXRD measurements revealed a decrease in long-range order already
above 150 °C. Furthermore, the Ce4+ based analogue
Ce-CAU-28 could be obtained employing dimethylformamide/water mixtures
as solvent. The structure and framework composition of this MOF are
very similar to the ones of the Zr-based compound, but its thermal
stability is clearly inferior. Thus, Ce-CAU-28 cannot be fully desolvated
and exhibits a specific surface area of only SBET = 360 m2/g and a micropore volume of 0.15 cm3/g
Green Synthesis of Zr-CAU-28: Structure and Properties of the First Zr-MOF Based on 2,5-Furandicarboxylic Acid
No full textA new Zr-based metal–organic
framework denoted as Zr-CAU-28 with framework composition [Zr6O4(OH)4(FDC)4(OH)4(H2O)4] (H2FDC = 2,5-furandicarboxylic
acid, CAU = Christian-Albrechts-University) was obtained under green
synthesis conditions from a mixture of H2O and acetic acid
and employing microwave-assisted heating. Zr-CAU-28 is the first Zr-MOF
based on H2FDC, which is often considered a promising renewable
alternative to terephthalic acid. The crystal structure was determined
from powder X-ray diffraction data using a combination of direct methods,
force field calculations, and Rietveld refinement. The compound crystallizes
in the hexagonal crystal system (space group P63/mmc) with the cell parameters a = 24.9919(9) and c = 24.7688(9) Å. The framework
structure adopts a kagome-like topology and hence contains large hexagonal
channels with a pore diameter of approximately 16 Å and small
trigonal channels with a size of 3 Å. Nitrogen sorption measurements
were carried out at −196 °C and gave a specific surface
area of SBET = 1006 m2/g and
a micropore volume of 0.42 cm3/g. Thermogravimetric analyses
showed a stability up to 270 °C although temperature dependent
PXRD measurements revealed a decrease in long-range order already
above 150 °C. Furthermore, the Ce4+ based analogue
Ce-CAU-28 could be obtained employing dimethylformamide/water mixtures
as solvent. The structure and framework composition of this MOF are
very similar to the ones of the Zr-based compound, but its thermal
stability is clearly inferior. Thus, Ce-CAU-28 cannot be fully desolvated
and exhibits a specific surface area of only SBET = 360 m2/g and a micropore volume of 0.15 cm3/g
L'età costituente. Italia 1945-1948
No full textItalia 1945-1948. Una proposta di lettura dell'età costituent
Figures of the analysed objects (C. Reckweg, CAU Kiel).
No full textFigures of the analysed objects (C. Reckweg, CAU Kiel).</p
La fondazione dell’Istituto storico italo-germanico. Le origini di un progetto politico-culturale
No full textI media nei processi elettorali. Modelli ed esperienze tra età moderna e contemporanea
No full textNella competizione politica contemporanea i media svolgono, com’è noto, un ruolo determinante, influenzando in profondità il circuito della comunicazione elettorale. È sempre stato così o si tratta di una peculiarità dell’orizzonte politico contemporaneo? Uno sguardo al passato permette di ricostruire forme, modelli e contenuti di un fenomeno che affonda le radici nella modernità. Il volume intende riflettere sulla funzione che i mezzi di comunicazione hanno svolto in differenti contesti elettorali. Accanto a contributi di carattere generale utili a inquadrare il tema, la ricerca, sviluppata in dialogo con le più recenti tendenze della storiografia italiana e tedesca dedicata ai media come attori dello sviluppo storico, si focalizza su alcuni casi di studio. La scelta di una campitura cronologica ampia, che va dalla prima età moderna al tardo Novecento, consente di mettere in evidenza i profili evolutivi di un fenomeno che attraversa nel lungo periodo la storia della comunicazione politica europea
coc-cau-wee
No full textcoccauwee...the long tailed duck (_Harelda_ _glacialis_)... is called the "cau-cau-wee", from the sound made by the males.PRINTED ITEM G.M Story July 1963Not UsedNot UsedWithdrawn(see 'cockawee')Checked by Jordyn Hughes on Mon 04 Jul 201
- …
