ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Springer  (41)
  • Blackwell Science Ltd  (3)
  • International Union of Crystallography (IUCr)
  • 2000-2004  (17)
  • 1985-1989  (24)
  • 1960-1964  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Improved automated extraction and separation procedure for soil lipid analyses (2004)
    Oxford, UK; Malden, USA : Blackwell Science Ltd
    European journal of soil science 55 (2004), S. 0 
    Details
    ISSN: 1365-2389
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Analysis of soil lipids may contribute to an improved understanding of atmosphere to soil carbon fluxes, soil organic matter source differentiation and pollutant accumulation. Soil lipids, mostly originating from plants and microorganisms, have traditionally been analysed by non-automated extraction and separation methods, which produce several lipid fractions, operationally defined by polarity. Here we present a combination of fast, automated and reproducible techniques, adopted from organic geochemical studies, for preparative separation of individual soil lipid fractions with increasing polarity. These techniques involve commercially available instruments, including accelerated solvent extraction and a two-step automated medium-pressure liquid chromatography procedure. The method yields eight lipid fractions consisting of five fractions fully amenable to gas chromatography/mass spectrometry (GC/MS) (aliphatic hydrocarbons, aromatic hydrocarbons, ketones, alcohols, carboxylic acids), and three fractions of highly polar or high molecular weight compounds (bases, very long-chain wax esters (C40+), high polarity compounds) that were not measurable with GC/MS under standard conditions. We tested the method on five agricultural soils. Results show that (i) mass recoveries for the individual fractions are reproducible, (ii) within individual fractions compound distribution patterns are reproducible, as demonstrated for alkanes and carboxylic acids, and (iii) individual fractions represent distinct and clean compound classes, free of interfering substances detectable by GC/MS. Thus, automated separation can be a fast, effective and reproducible procedure for fractionation of complex mixtures of soil lipids into clean compound classes, directly suitable for a variety of molecular (e.g. GC/MS) and isotopic characterizations (e.g. gas chromatography coupled with isotope ratio monitoring mass spectrometry or accelerator mass spectrometry).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1351-0754.2004.00601.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Organic matter in particle-size fractions from A and B horizons of a Haplic Alisol (2002)
    Oxford, UK : Blackwell Science Ltd
    European journal of soil science 53 (2002), S. 0 
    Details
    ISSN: 1365-2389
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The organic matter in soils may be stabilized by its interactions with minerals. We have studied such interactions in a Haplic Alisol under forest in which clay and organic matter have migrated from an eluvial A horizon to accumulate in an illuvial B horizon. We have tried to trace the fate of organic matter in these horizons (Ah and Bvt) by determining clay mineralogy, carbon and nitrogen content, hydrolysable amino acids, lignin signature by alkaline CuO oxidation and carbon species by 13C CPMAS NMR of bulk soils and particle-size fractions. In both horizons, most of the organic matter was present in O–alkyl and methylene structures, each contributing one-third to the bulk organic matter. In the Ah horizon the ratios of carbon-to-nitrogen, and yields for lignin and hydrolysable amino acids decreased as the particle-size class decreased, but side-chain oxidation of lignin compounds increased with decreasing particle size. In contrast to previous observations, the proportions of O–alkyl carbon increased as particle size decreased, constituting a major proportion of the organic carbon in the clay-size fractions from both the Ah and Bvt horizons (≥ 38%), while proportions of methylene carbon decreased. Illite was the dominant mineral in the fraction ≤ 6 μm, whereas the mobile fine clay fraction (〈0.2 μm) was rich in smectites – minerals with large surface areas. Our results support the hypothesis that potentially labile organic matter, such as O–alkyl carbon typically present in polysaccharides, may be stabilized against further degradation in organomineral complexes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2389.2002.00460.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Never say never again: protein glycosylation in pathogenic bacteria (2002)
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 45 (2002), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: In recent years, accumulating evidence for glycosylated bacterial proteins has overthrown an almost dogmatic belief that prokaryotes are not able to synthesize glycoproteins. Now it is widely accepted that eubacteria express glycoproteins. Although, at present, detailed information about glycosylation and structure–function relationships is available for only few eubacterial proteins, the variety of different components and structures observed already indicates that the variations in bacterial glycoproteins seem to exceed the rather limited display found in eukaryotes. Numerous virulence factors of bacterial pathogens have been found to be covalently modified with carbohydrate residues, thereby identifying these factors as true glycoproteins. In several bacterial species, gene clusters suggested to represent a general pro-tein glycosylation system have been identified. In other cases, genes encoding highly specific glycosyltransferases have been found to be directly linked with virulence genes. These findings raise interesting questions concerning a potential role of glycosylation in pathogenesis. In this review, we will therefore focus on protein glycosylation in Gram-negative bacterial pathogens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2958.2002.03030.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Electron density studies of KCl and LiF by γ-ray diffractometry (1985)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 41 (1985), S. 171-175 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Use of hard electromagnetic radiation (λ = 0.12 Å) in diffraction experiments, in conjunction with thin crystals in transmission geometry (Laue case), minimizes multiple scattering, often referred to as the 'extinction problem'. A large crystal slab, completely intercepting the incident beam, was used in this experiment. Several structure factors have been measured in LiF and KCl, with greater accuracy than ever before, using the γ-ray spectrometer of the University of Missouri at Columbia. In the case of LiF the results indicates some compression of the valence electron densities, similar to what has been found earlier for NaF. In the case of KCl all reflections agree well with the values calculated from free-atom Hartree-Fock wave functions except for the 004 and 006, which are appreciably weaker than corresponding reflections with similar or identical sin θ/λ values. This result indicates asphericity of the valence electron density. The 111 is also much weaker than the calculated value, indicating that the negative ions are slightly compressed and the positive ions slightly expanded with respect to the free-ion charge densities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108767385000344
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Strong impact of the electron-photon matrix element on angle-resolved photoelectron spectra of Sr 2 CuO 2 Cl 2 (2001)
    Springer
    The European physical journal 23 (2001), S. 69-77 
    Details
    ISSN: 1434-6036
    Keywords: PACS. 74.72.Jt Other cuprates – 79.60.-i Photoemission and photoelectron spectra – 74.25.Jb Electronic structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: In recent years insight has been gained into the electronic structure of layered cuprates using angle-resolved photoelectron spectroscopy. In many of these studies it is assumed that the electron-photon matrix element follows the trends set by the atomic photoionization cross sections and does not influence lineshape, dispersion and the k-dependence of the spectral intensity. In this study using Sr2CuO2Cl2 as an example it will be shown that the electron-photon matrix element can have a strong impact on both strength and shape of a feature in an angle-resolved photoelectron spectrum of a layered cuprate which can strongly affect information on character and the momentum-dependence of the energy and spectral weight of a state deduced from the spectra. The results of this study put an emphasis on the need to employ the whole parameter range of the ARPES method to get reliable information on the spectral function of cuprates for which purpose synchrotron radiation is an uniquely suited tool.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100510170083
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The production of charginos of theSU(N, 1) minimal sugra model ine + e − annihilation andp $$\bar p$$ collider experiments (1987)
    Springer
    The European physical journal 36 (1987), S. 715-723 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present cross sections for the charged lepton production from the lightest charged superpartner particles predicted by theSU(N, 1) Minimal SUGRA model, either the superpartners of the r.h. charged leptons or the Wino/Higgsino. At least one of these should appear in the decay of theZ, which is produced ine + e −-annihilation-presumably soon at the SLC — or inp $$\bar p$$ collider experiments. A large missing mass and strong deviations from back to back production of lepton pairs (and possibly ae-μ final state) would indicate such charged massive intermediate particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01630608
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The neutralinos of theSU(N,1) minimal supergravity model and standard cosmology (1988)
    Springer
    The European physical journal 40 (1988), S. 591-598 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We discuss the effect of the lightest supersymmetric particle (LSP), a Higgsino, and of the gravitino of theSU(N,1) minimal SUGRA model in the standard big bang theory. The freeze out of the LSP depends on the gravitino mass and on the top mass and leads to restrictive lower bounds for these parameters in the model. The decay of a gravitino with mass in the few TeV range leads to a delay in the cooling of the universe before nucleosynthesis. This constitutes the main bound on the gravitino mass of the model. The results are compared with the more standard “simultaneous decay approximation”.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01560230
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Defect generation in polycrystalline Cu(In,Ga)Se2 by high-energy electron irradiation (2000)
    Springer
    Applied physics 70 (2000), S. 677-680 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 61.80.Fe; 61.82.Fk; 84.60.Jt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. We investigate the degradation of ZnO/CdS/ Cu(In,Ga)Se2 heterojunction solar cells for space applications and the defect generation in polycrystalline Cu(In,Ga)Se2 thin films by irradiation with 1-MeV electrons with fluences φe up to φe=5×1018 cm-2. Notable degradation of the solar cell performance starts at fluences of φe=1017 cm-2 where the open circuit voltage decreases by about 5% while short circuit current and fill factor remain essentially unaffected. Thus, Cu(In,Ga)Se2 solar cells withstand electron fluences which are higher by one order of magnitude or more when compared to other technologies. A model describes the absolute open circuit voltage loss considering the increase of space charge recombination by electron irradiation-induced defects. Defect analysis by admittance spectroscopy shows that acceptor defects with an energy distance of approximately 300 meV from the valence band are generated at a rate γ=0.017 (±0.01) cm-1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050014
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Observations on the history of central B-splines (1988)
    Springer
    Archive for history of exact sciences 39 (1988), S. 137-156 
    Details
    ISSN: 1432-0657
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00348440
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Alignment and application of the conical shadowgraph flow visualization technique (1986)
    Springer
    Experiments in fluids 4 (1986), S. 93-96 
    Details
    ISSN: 1432-1114
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract An optical bench study has been carried out to assess the effects of both beam alignment and nonconical disturbances in the application of conical shadowgraphy for flow visualization. Conical and quasiconical plastic test models were immersed in a refractive index matching fluid and then examined by shadowgraphy with a conical light beam. The results show that problems of interpretation may arise due to both axial and transverse beam misalignment. Among these difficulties, axial misalignment with positive vertex displacement is the least serious. Also, the effect of a particular nonconical disturbance field was found to introduce fewer difficulties of interpretation than that of beam misalignment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00266565
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...