Search Results

Now showing 1 - 10 of 38
  • Item
    Spectral surface albedo over Morocco and its impact on radiative forcing of Saharan dust
    (Abingdon : Taylor & Francis, 2009) Bierwirth, E.; Wendisch, M.; Ehrlich, A.; Heese, B.; Tesche, M.; Althausen, D.; Schladitz, A.; Müller, D.; Otto, S.; Trautmann, T.; Dinter, T.; Von Hoyningen-Huene, W.; Kahn, R.
    In May-June 2006, airborne and ground-based solar (0.3-2.2 μm) and thermal infrared (4-42 μm) radiation measurements have been performed in Morocco within the Saharan Mineral Dust Experiment (SAMUM). Upwelling and downwelling solar irradiances have been measured using the Spectral Modular Airborne Radiation Measurement System (SMART)-Albedometer. With these data, the areal spectral surface albedo for typical surface types in southeastern Morocco was derived from airborne measurements for the first time. The results are compared to the surface albedo retrieved from collocated satellite measurements, and partly considerable deviations are observed. Using measured surface and atmospheric properties, the spectral and broad-band dust radiative forcing at top-of-atmosphere (TOA) and at the surface has been estimated. The impact of the surface albedo on the solar radiative forcing of Saharan dust is quantified. In the SAMUM case of 19 May 2006, TOA solar radiative forcing varies by 12 W m-2 per 0.1 surface-albedo change. For the thermal infrared component, values of up to +22 W m-2 were derived. The net (solar plus thermal infrared) TOA radiative forcing varies between -19 and +24 W m-2 for a broad-band solar surface albedo of 0.0 and 0.32, respectively. Over the bright surface of southeastern Morocco, the Saharan dust always has a net warming effect. © 2008 The Author Journal compilation © 2008 Blackwell Munksgaard.
  • Item
    Nucleoside analogues from push-pull functionalized branched-chain pyranosides
    (Berlin : de Gruyter, 2006) Kordian, M.; Feist, H.; Kantlehner, W.; Michalik, M.; Peseke, K.
    The reaction of methyl 4,6-O-benzylidene-2-deoxy-α-D-erythro- hexopyranosid-3-ulose (1) with ethynylmagnesium bromide in tetrahydrofuran and subsequent trimethylsilylation yielded the methyl 4,6-O-benzylidene-2-deoxy-3-C- ethynyl-3-O-trimethylsilyl-α-D-ribo-hexopyranoside (3). Push-pull functionalization of 3 with N,N,N′,N′,N″,N″- hexamethylguanidinium chloride under basic conditions and following deprotection afforded the spiro{2,5-dihydro-3-dimethylamino-furan-2,8'-4',4'a,6',7',8',8'a- hexahydro-6'-methoxy-2'-phenyl-pyrano[3,2-d][1,3]dioxine}-5- ylidenemalononitrile (9). Furthermore, compound 1 reacted with N,N-dimethylformamide dimethylacetal to furnish methyl (E)-4,6-O-benzylidene-2- deoxy-2-dimethylaminomethylene-α-D-erythro-hexopyranosid-3-ulose (10). Treatment of 10 with methylhydrazine and amidines yielded (4S,5aR,8R,9aS)-2,5a, 6,9a-tetrahydro-4-methoxy-2-methyl-8-phenyl-4H-[1,3]dioxino[4',5':5,6]pyrano[4, 3-c]pyrazole (11a) and (2R,4aR,6S,10bS)-4,4a,6,10b-tetrahydro-6-methoxy-2- phenyl[1,3]dioxino[4',5':5,6]pyrano[4,3-d]pyrimidines 12, respectively. © 2006 Verlag der Zeitschrift für Naturforschung.
  • Item
    Crystal structure of tris[(diphenylphosphino)methylene)- diphenylphosphoranylmethyl]yttrium diethyl ether monosolvate, [Y{P(C6H5)2CHP(C6H5)2CH2}3] (C2H5)2O
    (München : R. Oldenbourg Verlag GmbH, 2005) Spannenberg, A.; Müller, B.H.; Rosenthal, U.
    C82H79OP6Y, monoclinic, P12/cl (no. 13), a = 24.392(5) Å,b= 12.632(2) Å, c = 23.709(5) Å, β = 100.97°, V = 7171.8 Å3, Z = 4, Rgt(F) = 0.054, wRref(F2) = 0.112, T = 200 K.
  • Item
    Crystal structure of [1,2-ethylene-1,1′ -bis(η5-tetrahydroindenyl)]-chloro- [η2-N,C-3,4,5,6-tetrafluoropyridyI]zirconium(IV), ZrCl(C5F4N)(C20H24)
    (München : R. Oldenbourg Verlag GmbH, 2005) Spannenberg, A.; Jäger-Fiedler, U.; Arndt, P.; Rosenthal, U.
    C25H24Clf4NZr, monoclinic, P121/n1 (no. 14), a = 9.903(2) Å, b= 11.279(2) Å, c = 20.231(4) Å, β = 92.43(3)°, V = 2257.7 Å3, Z = 4, Rgt(F) = 0.035, wRobs(F2) = 0.076, T = 200 K.
  • Item
    Crystal structure of tetraholmium nickel tetradecaboride, Ho4NiB14
    (München : R. Oldenbourg Verlag GmbH, 2001) Geupel, S.; Zahn, G.; Paufler, P.; Graw, G.
    B14Ho4Ni, tetragonal, P4/mnc (No. 128), a = 7.2097(8) Å, c = 7.4587(9) Å, V = 387.7 Å3, Z = 2, Rgt(F) = 0.049, wRref(F2) = 0.087, T = 300 K.
  • Item
    Crystal structure of bis(η5-cyclopentadienyl)-pyrrolide- titanium(III), Ti(C10H15)2(C4H 4N)
    (Berlin : de Gruyter, 2007) Spannenberg, A.; Burlakov, V.V.; Arndt, P.; Klahn, M.; Rosenthal, U.
    C24H34NTi, orthorhombic, Pbcm (no. 57), a = 10.864(2) Å, b = 14.281(3) Å, c = 27.535(6) Å, V= 4272.0 Å3, Z = 8, Rgt(F) = 0.043, wRref(F 2) = 0.111, T= 200 K. © by Oldenbourg Wissenschaftsverlag,.
  • Item
    Crystal structures of tribromo(η5-3,6-di-tert-butyl-9,10,11- trimethyl-bicyclo(6.3.0)undeca-4-en-8,10-dienyl)titanium(IV), Ti(C 22H35)Br3, and tribromo(η5-4,5- dibromo-3,6-di-tert-butyl-9,10,11-trimethyl-bicyclo(6.3.0)undeca-8,10-dienyl) titanium(IV), Ti(C22H35Br2)Br3
    (Berlin : de Gruyter, 2008) Spannenberg, A.; Burlakov, V.V.; Rosenthal, U.
    C22H35Br3Ti, triclinic, P1̄ (no. 2), a = 9.621(2) Å, b = 11.796(2) Å, c = 12.232(2) Å, α = 102.23(3)°, β = 97.71(3)°, γ = 112.32(3)°, V = 1219.2 Å3, Z = 2, Rgt(F) = 0.058, wRobs(F 2) = 0.134, T = 293 K. C22H35Br5Ti, monoclinic, P121/n1 (no. 14), a = 7.474(1) Å, b = 18.458(4) Å, c = 20.171(4) Å, β = 100.28(3)°, V= 2738.0 Å3, Z = 4, Rgt(F) = 0.054, wRobs(F 2) = 0.119, T = 293 K. © by Oldenbourg Wissenchaftsverlag.
  • Item
    Crystal structure of 1, 1-bis(pentamethylcyclopentadienyl)-4, 5-bis(trimethyIsilyl)-1-hafnafuran-3-one, Hf(C10H15) 2(Me3SiC2SiMe3CO2)
    (Berlin : de Gruyter, 2009) Beweries, T.; Burlakov, V.V.; Rosenthal, U.; Spannenberg, A.
    C29H48HfO2Si2, orthorhombic, Pnma (no. 62), a = 16.8546(4) Å= 14.4139(6) Å= 12.1421(3) Å, V= 2949.8 Å3, Z = 4, Rgt(F) = 0.020, WR ref(F2) = 0.041, T= 200 K. © by Oldenbourg Wissenschaftsverlag.
  • Item
    Refinement of the crystal structure of praseodymium orthoscandate, PrScO3
    (Berlin : de Gruyter, 2009) Gesing, T.M.; Uecker, R.; Buhl, J.-C.
    O3PrSc, Prima (no. 62), a = 5.780(1) Å, b = 8.025(2) Å, c = 5.608(1) Å, V= 260.1 Å3, Z = 4, R gr(F) = 0.025, wRref(F2) = 0.060, T= 298 K. © by Oldenbourg Wissenschaftsverlag, München.
  • Item
    Crystal structure of dichloro((S)-2-(anilinomethyl)-pyrrolidine)- palladium(II), Pd(Cl)2(C11H16N2)
    (Berlin : de Gruyter, 2007) el Firdoussi, L.; Ali, M.A.; Karim, A.; Spannenberg, A.
    C11H16Cl2N2Pd, orthorhombic, P212121 (no. 19), a = 11.246(2) Å, b = 12.222(2) Å, c = 19.637(4) Å, V= 2699.1 Å3, Z = 8, Rgt(F) = 0.027, wRref(F2) = 0.060, T =200 K. © by Oldenbourg Wissenschaftsverlag,.