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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 42 (1986), S. 107-107 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0789
    Keywords: Dactyladenia barteri ; Leucaena leucocephala ; Lignin ; Nitrogen mineralization ; Nitrogen leaching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The evolution of mineral and hydrosoluble organic N released from two soils differing in pH and treated with leaves of Leucaena leucocephala (0, 8.3, 16.7, and 33. g kg-1 soil), Dactyladenia barteri (syn. Acioa barteri; 0 and 16.7 g), and their mixtures was studied in the laboratory using the aerobic incubation-leaching method. N mineralization in untreated soils and in soils supplemented with 8.3 g leucaena leaves was 41–53% higher in the soil from Onne (pH 4.7) than in the soil from Ibadan (pH 6.2), but the organic N content was similar with these treatments in the leachates of the soils from both locations. The application of 16.7 or 33.3 g of either or both type of leaves reduced the rate of mineral N production during the first 4 weeks, particularly in soils treated with dactyladenia leaves (C:N=36). After this lag period, N mineralization proceeded at a faster rate in the soil from Ibadan treated with 16.7 or 33.3 g of leucaena leaves (C:N=12), even in the presence of dactyladenia leaves. In Ibadan soil, after 12 weeks, mineral N apprently derived from leaves of both dactyladenia and leucaena averaged 6.3% of the N applied, and organic N from leaves averaged 9.5%. The addition of dactyladenia and leucaena leaves did not increases the mineral N content in the acid soil from Onne but leaching of soluble organic N with addition of 16.7 or 33.3 g of leaves contributed an N-mineralizable pool of 5.9% of the N applied.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 259-261 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The characteristics of Schottky diodes on n-GaAs fabricated after an in situ low-pressure rf H2 plasma treatment have been investigated as a function of the substrate temperature during the plasma treatment. Degraded rectifying characteristics result after room-temperature treatments, while diodes with ideality factor as low as 1.01 were achieved in the temperature range 160–240 °C. An increase in barrier height was also observed with increasing substrate temperature during plasma treatment. The contact properties are correlated to H diffusion in a surface layer of GaAs, which passivates the dopant atoms and defect sites.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 2356-2364 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The influence of the GaAs surface condition on the properties and thermal stability of WNx Schottky diodes on GaAs has been studied by performing in situ H2 and N2 plasma treatments just before the WNx sputter deposition. The WNx/GaAs contacts have been investigated by x-ray photoelectron spectroscopy, Rutherford backscattering, nuclear reaction analysis, secondary ion-mass spectroscopy, x-ray diffraction, and transmission electron microscope and correlated to electrical current-voltage and capacitance-voltage measurements. A strong correlation was found between the diode properties and the surface conditions, both for the as-deposited samples and for samples annealed in the range 700–850 °C. Poor rectifying properties were obtained for the plasma-cleaned diodes due to the cumulative effects of plasma cleaning and sputter deposition. After annealing, improved characteristics were generally found. The highest Schottky barrier height values φI-V=0.76 V, which were found for the H2 plasma treated diodes annealed at 800 °C, were almost independent of the WNx composition and sputtering conditions. The H2 treated samples also showed the smoothest WNx/GaAs interface. HCl cleaned and N2 treated surface also showed high-barrier height and small interfacial reactions after high-temperature annealing.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 2642-2644 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The high-power integrity of strained single quantum well InGaAs/AlGaAs lasers grown by molecular beam epitaxy is investigated. In the high-power regime, the lifetime of the Lz=7 nm strained quantum well laser emitting at (approximately-equal-to) 980 nm is found to be limited by the air-cleaved facets. However, a comparison with lattice-matched 7 nm quantum well GaAs/AlGaAs lasers, which otherwise have an almost identical vertical structure shows a substantial lifetime improvement. This indicates that lattice hardening due to the indium in the quantum well is effective in the facet region. The investigations demonstrate the feasibility of 150 mW single mode operation with sufficient lifetime for practical applications in the wavelength range of (approximately-equal-to)1 μm.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Certain brain gut-peptides are known to either stimulate or inhibit gastric acid secretion in several species after direct injection into the central nervous system. However there is inconsistency of published results on the gastric acid secretory response to some of these peptides after peripheral administration in different experimental systems. Seven peptides, namely neurotensin (NT), substance P, cholecystokinin (CCK), thyrotropin releasing hormone (TRH), human calcitonin (hCT), rat calcitonin-gene-related peptide (rCGRP) and bombesin, all known to modulate gastric acid secretion after central administration, were initially screened for activity after peripheral (subcutaneous) injection of 10 μg/kg body weight in a single rat model. Peptides showing an effect were retested at lower doses. Despite the inherent variability of the gastric acid secretory response in the non-anaesthetized pylorus ligated rat, a standardized experimental design confirmed that reproducible and statistically valid results could be obtained. The technical feasibility of using a one hour collection period as might be appropriate for short acting peptides was demonstrated by the significant dose dependent inhibitory activity of salmon calcitonin. In this model, NT and substance P had no significant effect on either volume or concentration of acid secreted, CCK showed a slight stimulation of acid output, and TRH, hCT, rCGRP and bombesin all inhibited acid output; CGRP and bombesin were active at 10 and 100-fold lower doses. The potent and inhibitory activity of bombesin in this system is in disagreement with other publications reporting no effect or variable stimulatory effect in rats. Time and dose dependent responses in our rat system indicate that this apparent discrepancy may be explained by the short duration of action of bombesin.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 22 (1993), S. 525-527 
    ISSN: 1432-2161
    Keywords: Os odontoideum ; Atlas and axis, abnormalities ; Atlas and axis, fractures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Most authorities favor the hypothesis of an acquired etiology of os odontoideum. We present the cases of identical twin sisters with os odontoideum in association with a congenital partial fusion of the posterior elements of the second and third cervical vertebrae, and discuss the implications. We believe that this is the first report of familial os odontoideum in a context which suggests a genetic etiology.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 42 (1986), S. 107-107 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 9
    ISSN: 1434-6079
    Keywords: 34.50 ; 34.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract K α X-ray spectra were measured with a Du Mond type curves crystal spectrometer for42Mo and46Pd targets bombarded with oxygen ions at 5.5 MeV/u energy (i.e. at velocity closely matching those of the targetL-shell electrons). The distribution ofL-shell vacancies produced in collisions with simultaneousK-shell ionization is deduced from the measured yield distribution of theK α X-ray satellites. The distribution shows deviations from the binomial ones. The deviations can be accounted for by assuming that theL-shell vacancy production is due to two uncorrelated processes: the direct ionization by impact and the electron capture from theL-shell of the target atom into theK-shell of the projectile, both occurring at nearly central collisions. The corresponding probability values are deduced using simple statistical considerations.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1434-6079
    Keywords: 34.50.H ; 32.20.R ; 32.70.J
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract TheKβ spectra of molybdenum, palladium and lanthanum bombarded by 6.7 MeV/amu4He ions were measured with a transmission curved crystal spectrometer.L andM satellite lines were observed and resolved. Experimental energies are compared with those calculated with a MCDF program.M -shell ionization probabilities are deduced from the measured satellite intensity ratios and compared with theoretical (SCA) predictions. The experimental values are found to be higher than the calculated ones (by a factor of 2 for La and a factor of about 4 for Mo and Pd). The influence of coupling effects, electron wave functions, electron capture, electron correlation and target activation is discussed.
    Type of Medium: Electronic Resource
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