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
  • 1
    Electronic Resource
    Electronic Resource
    Asymmetric hetero-Diels-Alder reactions: X-ray structures of three novel chiral dihydropyrimidines (1998)
    Springer
    Journal of chemical crystallography 28 (1998), S. 663-671 
    Details
    ISSN: 1572-8854
    Keywords: Pyrimidine ; carboxamide ; sulfonyl ; chiral ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Three novel dihydropyrimidine compounds N8,6-di(4-nitrophenyl)-(3R)-ethyl-(7R)-methyl-5-oxo-2,3,6,7-tetrahydrooxazolo[3,2,c] pyrimidine-8-carboxamide (2), N8,6-di((4-methylphenyl)-sulfonyl)-(3R)-ethyl-5-oxo-(7R)-phenyl-2,3,6,7-tetrahydrooxazolo [3,2,c]pyrimidine-8-carboxamide (3) and N8,6-di ((4-methylphenyl)sulfonyl)-(3R)-ethyl-(7R)-methyl-5-oxo-2,3,6,7-tetrahydrooxazolo[3,2,c] pyrimidine-8-carboxamide (4) have been prepared (from 2-amino-1-butanol of 64.4% e.e.) and structurally characterized by X-ray crystallography. All three compounds contain stereogenic centers, but the crystal of (2) chosen was found to be racemic whilst those of (3) and (4) were found to be homochiral. Compound (2) crystallizes in the monoclinic space group P21/c, with a = 17.958(4), b = 12.431(2), c = 9.653(2) Å, β = 96.20(3)°, U = 2142.3(7) Å3, Z = 4, and D c = 1.449 g cm−3. Compounds (3) and (4) both crystallize in the monoclinic space group P21, with a = 9.349(2), b = 5.824(5), c = 26.513(8) Å, β = 99.43(2)°, U = 1424.1(13) Å3, Z = 2 and D c = 1.389 g cm−3 for (3), and a = 5.9526(9), b = 16.3521(10), c = 13.2263(11) Å, β = 92.81(12)°, U = 1285.9(2) Å3, Z = 2 and D c = 1.378 g cm−3 for (4).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021791832534
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Relativistic Kronig-Penney-type Hamiltonians (1998)
    Springer
    Integral equations and operator theory 31 (1998), S. 436-448 
    Details
    ISSN: 1420-8989
    Keywords: 81Q10 ; 35J10
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The relativistic Kronig-Penney model is extended to a wide class of point interactions introduced in the nonrelativisfic case by Paul Chernoff and the author. A generalized Kronig-Penney relation, which converges to the standard Kronig-Penney relation in the nonrelativistic limit, is shown to determine the spectrum of the corresponding Hamiltonian. Several examples are considered, including the well-known special cases of electrostatic and Lorentz scalar point interactions, as well as several new solvable models.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01228101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Enzymic involvement in the biogeochemical responses of a Welsh peatland to a rainfall enhancement manipulation (1998)
    Springer
    Biology and fertility of soils 27 (1998), S. 173-178 
    Details
    ISSN: 1432-0789
    Keywords: Key words Wetland ; Peat ; Enzyme ; Climate change ; Increased rainfall
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Microbial enzyme activities were followed during a field-based experimental simulation of the effects of higher rainfall in a Welsh peatland. The treatment did not significantly affect the activities of the carbon cycling enzymes, β-glucosidase, esterase or xylosidase. In contrast, the activity of the enzyme sulphatase decreased by 44% (P〈0.001) in response to the wetter conditions. The manipulation suggests that should climate change cause conditions to become wetter in peatlands, then (with the exception of sulphatase) current levels of wetness may be sufficient to limit decomposition processes, and thus any further increase in wetness is unlikely to induce a further decrease in decomposition rates. Correlations were found between the esterase activity and both nitrous oxide flux (r=–0.44, P〈0.05), and methane release (r=0.53, P〈0.01). Likewise, there was a correlation between xylosidase activity and both carbon dioxide emission (r=0.52, P〈0.01) and aluminium concentration (r=0.58, P〈0.01). All of the enzymes correlated positively with dissolved organic carbon (range r=0.53, P〈0.01 sulphatase to r=0.61, P〈0.001 glucosidase). Together, the correlations lend support to recent hypotheses suggesting that enzymes exert an influence over wetland biogeochemical properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740050417
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Broadband degenerate four-wave mixing of OH for flame thermometry (1998)
    Springer
    Applied physics 67 (1998), S. 107-113 
    Details
    ISSN: 1432-0649
    Keywords: PACS: 42.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003400050482
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Synonymous and Nonsynonymous Substitution Distances Are Correlated in Mouse and Rat Genes (1998)
    Springer
    Journal of molecular evolution 47 (1998), S. 119-121 
    Details
    ISSN: 1432-1432
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00006367
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Comparative Evolutionary Rates of Introns and Exons in Murine Rodents (1998)
    Springer
    Journal of molecular evolution 46 (1998), S. 497-497 
    Details
    ISSN: 1432-1432
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00006330
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Regulatory budgeting (1998)
    Springer
    Policy sciences 31 (1998), S. 247-278 
    Details
    ISSN: 1573-0891
    Source: Springer Online Journal Archives 1860-2000
    Topics: Political Science , Economics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004499514780
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The Influence of Bi Doping on the In Situ Growth of TlBa2Ca2Cu3O9 High-T c Films (1998)
    Springer
    Journal of superconductivity 11 (1998), S. 603-607 
    Details
    ISSN: 1572-9605
    Keywords: TlBa2Ca2Cu3O9 ; films ; In Situ growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The in situ process—laser ablation in combination with thermal evaporation of Tl2O—has turned out to be a preparation method for single-phase and epitaxial TlBa2Ca2Cu3O9 (1223) thin films with T c values up to 109 K. It was found by several groups that a partial substitution of Tl by Bi simplifies the phase development of the 1223 compound in the usual two-step process. We have investigated the influence of the Bi doping on the in situ growth. X-ray measurements show that the films consisted mainly of the 1223 compound. In 300-nm thin films there was no evidence of a Bi amount in the crystal structure, but thinner films (80 nm) show a small amount of Bi. We concluded that Bi doping supports the phase development of the 1223 compound only in an early stage of the film growth. The Bi-doped films have higher T c values up to 114 K, higher j c values up to 6 × 105 A/cm2 (77 K, 0 T), and lower surface resistances of 56 mΩ (77 K, 87 GHz) than the undoped films.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022639430125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Status of Banana Streak Disease in Africa: Problems and Future Research Needs (1998)
    Springer
    Integrated pest management reviews 3 (1998), S. 85-97 
    Details
    ISSN: 1572-9745
    Keywords: Banana streak badnavirus ; diagnosis ; symptomatology ; research gaps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Streak disease of banana and plantain caused by banana streak virus (BSV) was first reported in the Ivory Coast in 1974 and occurs in at least 16 countries in Africa. Based on genomic characteristics, BSV has been shown to be a member of genus Badnavirus. Efficient and reliable diagnostic methods for BSV have recently become widely available. This paper summarizes the current knowledge on its causal agent, geographical distribution, symptomatology, transmission, host range, available diagnostic techniques and management options for the disease in Africa. Further research needs are identified in light of the widespread occurrence of BSV in most plantain/banana germplasms and the difficulties in obtaining BSV-free plantlets through tissue culture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009643713569
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Particle fabric in a small, type-2 ignimbrite flow unit (Laacher See, Germany) and implications for emplacement dynamics (1998)
    Springer
    Bulletin of volcanology 60 (1998), S. 125-136 
    Details
    ISSN: 1432-0819
    Keywords: Key words Particle fabric ; Ignimbrite ; Pyroclastic flow ; Flow unit ; Laacher See
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  Ignimbrites of the 13-ka Upper Laacher See Tephra were deposited from small, highly concentrated, moderately fluidized pyroclastic flows. Their unconsolidated nature, and the prominence of accidental Devonian slate fragments, make these ignimbrites ideal for clast fabric studies. The upper flow unit of ignimbrite M14 has characteristics typical of a type-2 ignimbrite. Layer 2a and the lower part of layer 2b of the flow unit have strong, upstream-inclined a[p] fabrics (a[p] means long particle axes parallel to flow direction). Only clasts with a/b axial ratios of 2.5 or greater preserve good a[p] fabrics, whereas the a–b planes of flat fragments dip upstream irrespective of axial ratio. The a-axis fabric becomes weaker, flatter, and more girdle-like in the upper half of layer 2b. At one locality the a-axis fabric appears to rotate 40° up through the flow unit, suggesting either shear decoupling of different levels in the moving flow or unsteadiness effects in a flow depositing progressively at its base. The existence of similarly strong a[p] fabrics in layer 2a and the lower half of layer 2b appears inconsistent with the common interpretation that ignimbrite flow units are emplaced as a plug of essentially non-shearing material (layer 2b) on a thin shear layer (layer 2a), and that the entire flow freezes en masse to form the deposit. The data suggest that, if the flow froze en masse, it was shearing pervasively through at least half its thickness. Another possibility is that the flow unit aggraded progressively from the base up, and that the fabrics record the integrated history of shear directions and intensities immediately above the bed throughout the duration of deposition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004450050221
    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...