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  (13)
  • Wiley  (4)
  • Oxford University Press
  • 1995-1999
  • 1990-1994  (17)
  • 1985-1989
  • 1980-1984
  • 1970-1974
  • 1990  (17)
  • 1
    Electronic Resource
    Electronic Resource
    Electrochemical impedance spectroscopy on porous electrodes (1990)
    Springer
    Journal of applied electrochemistry 20 (1990), S. 677-685 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Electrochemical d.c. and a.c. measurements have been carried out on porous Raney nickel in H2-saturated 0.1 M, 1 M, and 6 M NaOH solutions atT=303 K and 333 K using rotating-disc and static-plaar electrodes. For comparison, measurements were also performed on graphite-cloth and graphite-felt electrodes. From polarization curves and current transients obtained in the potential range of the hydrogen evolution and hydrogen oxidation reactions the dependence of the electrocatalytic activity of Raney nickel on the prepolarization conditions was studied. Impedance spectra in the frequency range 1 mHzf 10 kHz were used to determine the characteristic pore parameters and to identify the kinetic behaviour of the porous electrodes by application of transfer function analysis using non-linear fit routines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01008882
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Einfluß zentralnervöser koordination im Sinne v. HOLSTs auf die Steuerung von Atem- und Extremitätenmotorik des Menschen (1990)
    Springer
    Biological cybernetics 63 (1990), S. 457-462 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Description / Table of Contents: Zusammenfassung Am Beispiel rhythmischer Abduktions-Adduktionsbewegungen in Schulter- und Hüftgelenken konnten wir Änderungen im zeitlichen Atemablauf nachweisen, die als Phänomene zentralnervöser Koordination im Sinne v. Holsts gedeutet werden können. Sie traten in über 75% aller registrierten Atemzüge auf, wobei der Kopplungsgrad abhängig ist von Art und Anzahl periodisch bewegter Extremitäten, außerdem davon, ob ein äußerer Zeitgeber (akustisches Signal) für den Bewegungsrhythmus existiert oder nicht. Die Befunde weisen darauf hin, daß Reaktionen des motorischen Atemapparates nicht allein in Zusammenhang mit dessen homöostatischer Aufgabe und mit mechanischen Einflüssen interpretiert werden können. Die Steuerung der Atemmotorik erscheint eingeordnet in ein gesamtmotorisches Steuerungssystem. Damit wird auch ein Einfluß der Atemmotorik auf beliebige Skelettmotorik möglich. Koordination führt zur Ausbildung stabiler zeitlicher Beziehungen zwischen Atmung und zusätzlicher Bewegung, deren möglicher Nutzen in einer “energetischen Ökonomisierung” (Hildebrandt 1967) bestehen könnte.
    Notes: Abstract We found modulations in the time-course of breathing during rhythmic abduction-adduction movements in shoulder and hip joints which can be interpreted as phenomena of central coordination in the sense of v. Holst. They occurred in more than 75% of the recorded breaths. The strength of this coordination depends on number and kind of limbs moving rhythmically and on the use of an acoustic trigger signal (“Zeitgeber”) for the limb rhythm as well. Our findings indicate that reactions of the respiratory apparatus cannot be regarded only in connection with its homeostatic function and with mechanical influences. Breathing control appears integrated in the whole organism's “motor control system”. Therefore, an influence of breathing movements on other motor processes is possible as well. Coordination leads to a stable temporal order between breathing and additional movements. Its possible advantage could be an energetic economization as may be concluded from analogous phenomena in coupled non-linear oscillators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00199578
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Allocation of45calcium to body components of starved and fed purple sea urchins (Strongylocentrotus purpuratus) (1990)
    Springer
    Marine biology 105 (1990), S. 213-222 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several lines of evidence in the literature indicate that environmental stress such as starvation may initiate reallocation of sea urchin endoskeletal tissue. For example, Aristotle's lantern enlarges under conditions of starvation, and sea urchins tagged with tetracycline and then fed develop a distinct growth line, while starved individuals develop a diffuse pattern. We designed anin vivo system to examine stress-related changes in calcification in the purple sea urchinStrongylocentrotus purpuratus. SmallS. purpuratus (ca. 2 cm test diam) were collected from the Mission Bay jetty or Imperial Beach (San Diego, California, USA) in 1987.45Ca was incorporated from seawater into all body fractions including the organic tissue/coelomic fluid. In an initial experiment, sea urchins were fed or starved for 4 wk and then post-incubated in isotope. Overall, starved individuals deposited new calcite more slowly than did fed individuals; however, allocation was very different and calcification of teeth of starved sea urchins was nearly as great as in fed individuals. In a second experiment,S. purpuratus were first pre-labeled with isotope and then treated by feeding or starving. More of the labeled calcium was mobilized from the soft tissues and coelomic fluid into calcite in fed than in starved individuals. Growth of the teeth in starved sea urchins was significantly greater than in those fed. We conclude that starvation changes the metabolism of calcium in order to preferentially build teeth. However, we also found no evidence that calcium was resorbed from “old” skeletal calcite in order to build “new” skeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01344289
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Iron species in fusion-cast, glassy-phase-containing corundum materials; EPR and susceptibility analyses (1990)
    Springer
    Journal of materials science 25 (1990), S. 223-232 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract By means of EPR, susceptibility, EMP, light-microscopic, thermal and chemical methods the influence of production conditions and subsequent treatments on glassy-phase-containing corundum materials were studied. Melting of the system (Al2O3, SiO2, Na2O, Fe3O4) under reductive conditions leads to a reduction of Fe3+ species contained to Fe2+ and even to Fe0 clusters with ferromagnetic behaviour. Both species markedly influence the mechanical properties of the material by increase of their volumes in consequence of oxidation in subsequent thermal processes. The following model with regard to the localization of the iron species in the system ensues: Fe(III) in corundum, Fe2O3, Fe3O4 and (scarcely) in the glassy phase; Fe(II) in the glassy phase, FeAl2O4 (hercynite) as a solid solution in corundum, and Fe3O4; (Fe0) clusters in corundum. It is therefore not surprising that grinding of the compact material considerably alters the magnetic properties of the samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00544212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Transformation and regeneration of the self-incompatible species Nicotiana alata Link & Otto (1990)
    Springer
    Plant molecular biology 14 (1990), S. 815-824 
    Details
    ISSN: 1573-5028
    Keywords: Agrobacterium tumefaciens ; hypocotyls ; Nicotiana alata ; regeneration ; self-incompatibility ; transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A transformation and regeneration system has been developed for Nicotiana alata, a plant which is being intensively studied as a model of gametophytic self-incompatibility. Plantlets can be regenerated efficiently from seedling hypocotyls. Kanamycin-resistant, transformed plants have been obtained by cocultivation of regenerating hypocotyls with Agrobacterium tumefaciens strain LBA4404 containing a binary vector. The transformation frequency was low with 〈1% of tissue explants regenerating transformed plants. The transformed plants contained from one to three copies of the introduced DNA. In most cases, the kanamycin resistance phenotype was transmitted to the offspring as a normal Mendelian factor. In one unusual case, none of the offspring inherited the kanamycin resistance of the transformed maternal parent. This plant may have been chimeric or the kanamycin resistance gene may have been inactivated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00016514
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Phenotype and function of lymphocytes from colitis patients (1990)
    Springer
    Bulletin of experimental biology and medicine 110 (1990), S. 1540-1543 
    Details
    ISSN: 1573-8221
    Keywords: subpopulations of lymphocytes ; cytochemistry ; heterologous graft versus host reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00841316
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Ultracentrifuge studies on the interaction of some basic polypeptides with water-structure influencing anions (1990)
    Springer
    Colloid & polymer science 268 (1990), S. 1141-1147 
    Details
    ISSN: 1435-1536
    Keywords: Ultracentrifuge ; sedimentation-equilibriumrun ; poly-L-lysine ; N ε -methylated-poly-L-lysine ; anions ; molecularweight ; 2.virialcoef. ; part.specvolume andassociation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The aim of this work is to investigate the dependence of the molecular weight and the 2. virial coefficient of poly-L-lysine and N ε -methylated poly-L-lysine in solutions of water-structure-influencing anions. In the case of poly-L-lysine, the ultracentrifugal and CD-spectroscopic measurements show an increasing molecular weight and a complex between poly-L-lysine and the strong-water-structure-breaking anion ClO 4 − . In solutions of structure-forming anions, an independence of the molecular weight from the anion-concentration can be recognized. The 2. virial coefficient of structure-breaking anions is generally higher than for structure-forming anions. At a pH of 10.6, the molecular weight and the 2. virial coefficient is independent of the structure-breaking anion. In NaCH3 SO4 solutions, the tendency of the anion concentration and the molecular weight are parallel. Compared to this behavior, N ε -methylated poly-L-lysine was likewise investigated; it shows a similar trend of the molecular weight in dependence of the NaCH3 SO4 concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01410679
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Assessment of the changes of 2,4-dichlorophenoxyacetic acid concentrations in plant tissue culture media in the presence of activated charcoal (1990)
    Springer
    Plant cell, tissue and organ culture 20 (1990), S. 165-172 
    Details
    ISSN: 1573-5044
    Keywords: activated charcoal ; 2,4-D adsorption ; coconut palm ; tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The rate of adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) by activated charcoal (AC) from liquid and semi-solid tissue culture media was determined using 2-[14C]-2′,4′-D. In liquid medium 99.5% of the added 2,4-D (10-4 M) was adsorbed by AC (2.5 gl-1) within 5 days of preparation of the medium. Higher 2,4-D levels of reduced AC concentrations increased the level of available 2,4-D in the medium and extended the period necessary for the level of 2,4-D in the medium to become stabilized. In semi-solid medium the rate of adsorption of 2,4-D by AC was considerably reduced. A stable ratio of gel/2,4-D:AC/2,4-D was only reached after 10 to 20 days, depending on the 2,4-D concentration used. Low pH levels and maintenance of the medium at higher temperatures (20–30°C) accelerated the adsorption of 2,4-D by AC. In vitro tissue cultures of coconut palm showed marked differences in their growth response according to the age of the medium used and the associated variations in 2,4-D concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00041877
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Calculation of hyperfine interaction parameters in metals-friedel oscillations in dilute Fe and Cu alloys (1990)
    Springer
    Hyperfine interactions 60 (1990), S. 547-562 
    Details
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We review some recent calculations on hyperfine interaction parameters in metals based on density functional theory in the local density approximation. We restrict ourselves to the calculation of Friedel oscillations of the charge and magnetization density in dilute Fe and Cu alloys. In particular, we estimate hyperfine fields, isomer shifts and electric field gradients for a few shells around the impurities. The calculations are performed using the KKR-Green's function method. Especially, we discuss which valence properties determine the hyperfine interaction parameters and what information about the electronic structure can be obtained from their measurement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02399824
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    Iron species in fusion-cast, glassy-phase-containing corundum materials; EPR and susceptibility analyses (1990)
    Springer
    Details
    Publication Date: 1990-01-01
    Print ISSN: 0022-2461
    Electronic ISSN: 1573-4803
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...