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
    Der elektrische Widerstand eines Drahtgitters (1965)
    Springer
    Electrical engineering 50 (1965), S. 190-200 
    Details
    ISSN: 1432-0487
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Description / Table of Contents: Summary The article describes a method of calculating the resistance between two diagonal corners of a square network as a function of the number of meshes. The author defines a potential function, which holds good not only in the knots of the network, but also in the whole plane in which the network lies. This function can be calculated out of the impressed current and the boundary conditions with the help of the two-dimensional Laplace transformation. The boundary conditions of this function are ascertained. They allow the determination of the resistance in question and leads to an exact formula. A numerical estimation of the exact formula concludes the problem.
    Notes: Übersicht Der Aufsatz beschreibt ein Verfahren, nach dem sich der Widerstand zwischen zwei einander gegenüberliegenden Ecken eines quadratischen Gitters abhängig von der Maschenzahl berechnen läßt. Zunächst wird eine Potentialfunktion definiert, die nicht nur in den Knotenpunkten des Gitters erklärt ist, sondern in der ganzen Ebene, in der das Gitter liegt. Diese Funktion läßt sich mit der zweidimensionalen Laplace-Transformation aus den Einströmungen und den Randwerten berechnen. Die Randwerte dieser Funktion werden ermittelt. Sie gestatten, den gesuchten Widerstand zu bestimmen, so daß eine exakte Formel angegeben werden kann. Eine Abschätzung der gefundenen Formel rundet die Untersuchung ab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01574806
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Phylogenetic Composition, Spatial Structure, and Dynamics of Lotic Bacterial Biofilms Investigated by Fluorescent in Situ Hybridization and Confocal Laser Scanning Microscopy (1999)
    Springer
    Microbial ecology 37 (1999), S. 225-237 
    Details
    ISSN: 1432-184X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The phylogenetic composition, three-dimensional structure and dynamics of bacterial communities in river biofilms generated in a rotating annular reactor system were studied by fluorescent in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM). Biofilms grew on independently removable polycarbonate slides exposed in the reactor system with natural river water as inoculum and sole nutrient and carbon source. The microbial biofilm community developed from attached single cells and distinct microcolonies via a more confluent structure characterized by various filamentous bacteria to a mature biofilm rich in polymeric material with fewer cells on a per-area basis after 56 days. During the different stages of biofilm development, characteristic microcolonies and cell morphotypes could be identified as typical features of the investigated lotic biofilms. In situ analysis using a comprehensive suite of rRNA-targeted probes visualized individual cells within the alpha-, beta-, and gamma-Proteobacteria as well as the Cytophaga–Flavobacterium group as major parts of the attached community. The relative abundance of these major groups was determined by using digital image analysis to measure specific cell numbers as well as specific cell area after in situ probing. Within the lotic biofilm community, 87% of the whole bacterial cell area and 79% of the total cell counts hybridized with a Bacteria specific probe. During initial biofilm development, beta-Proteobacteria dominated the bacterial population. This was followed by a rapid increase of alpha-Proteobacteria and bacteria affiliated to the Cytophaga–Flavobacterium group. In mature biofilms, alpha-Proteobacteria and Cytophaga–Flavobacteria continued to be the prevalent bacterial groups. Beta-Proteobacteria constituted the morphologically most diverse group within the biofilm communities, and more narrow phylogenetic staining revealed the importance of distinct phylotypes within the beta1-Proteobacteria for the composition of the microbial community. The presence of sulfate-reducing bacteria affiliated to the Desulfovibrionaceae and Desulfobacteriaceae confirmed the range of metabolic potential within the lotic biofilms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002489900148
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    “Natural” chicken antibodies to red blood cells are mainly directed against the B-G antigen, and their occurrence is independent of spontaneous autoimmune thyroiditis (1984)
    Springer
    Immunogenetics 19 (1984), S. 269-277 
    Details
    ISSN: 1432-1211
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Using an indirect hemagglutination assay we tested sera from 94 healthy normal White Leghorn (NWL) and 117 Obese strain (OS) chickens with spontaneous autoimmune thyroiditis for the presence of “natural” antibodies against major histocompatibility complex (MHC) antigens expressed on red blood cells (RBC). In both groups older animals had a significantly increased frequency of such antibodies, but the titer was age-independent. OS chickens showed almost the same frequency of natural antibodies as NWL, and a comparison between OS birds with high antithyroglobulin autoantibody (Tg-AAb) titers and those with low titers also did not reveal a significant difference. We conclude that the occurrence of natural antibodies has no relation to Tg-AAb. The specificity of natural antibodies for MHC-encoded antigens was investigated in indirect immunofluorescence tests including absorption experiments with RBC and white blood cells (WBC). This analysis revealed that of 14 MHC-specific sera 13 were reacting with the B-G antigen, which is present on RBC only. One serum reacted with the B-F antigen, expressed on all somatic cells, i. e., both on RBC and WBC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00345400
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Controlled lateral manipulation of single molecules with the scanning tunneling microscope (1995)
    Springer
    Applied physics 60 (1995), S. 343-345 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 68.35.Bs
    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 report on the first successful lateral manipulation of molecules and controlled formation of nanostructures with the Scanning Tunneling Microscope (STM) at temperatures above 4 K as used by Eigler and collaborators. Among the first structures, we built the letters F and U forming the logo of our university at 30 K with CO molecules on a Cu(211) substrate. Our method to manipulate the molecules is analogous to that employed successfully up to now only by Eigler and co-workers. First experiences concerning the manipulation of the CO molecules on the highly anisotropic substrate are presented and the crucial role of the tip composition in imaging the CO molecules is demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01538415
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Influence of protein dynamics on the metal-sites of ovotransferrin (1992)
    Springer
    European biophysics journal 21 (1992), S. 147-154 
    Details
    ISSN: 1432-1017
    Keywords: Ovotransferrin ; Protein dynamics ; Time differential perturbed angular correlations ; Electric quadrupole interaction ; Relaxation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Using the perturbed angular correlations (PAC) technique, the formation of hafnium-ovotransferrin complexes has been studied. Two binding configurations at each of the two specific binding-sites of the protein have been observed. They are characterized by well-defined electric quadrupole frequencies. Information about the dynamics of the protein was derived from temperature dependent measurements of the relaxation constant. The well-resolved spectra taken with fast BaF2-detectors allow a precise determination of the relaxation behaviour of the protein. The results are compared with the predictions from a hydrodynamic model for the reorientation of macromolecules. Thus the hydrodynamic volume of ovotransferrin and its N-terminal half-molecule were determined. The ovotransferrin volume is in agreement with a value derived for human serum transferrin from small angle neutron scattering. From experiments with immobilized protein material there is evidence for internal protein dynamics which is probed by the Hf-ion bound to the specific metal-sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185429
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Optical investigations of GaAs/Ga1−x Al x As Quantum wells grown by molecular-beam epitaxy (1988)
    Springer
    Il nuovo cimento della Società Italiana di Fisica 10 (1988), S. 1093-1114 
    Details
    ISSN: 0392-6737
    Keywords: Interfaces ; PACS 71.35 ; Excitons and related phenomena (including electron-hole drops)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Sono state effettuate misure di fotoluminescenza, di fotoeccitazione e di riflettività, a varie temperature, su una serie di strutture a pozzi quantici GaAs/Ga1−x Al x As, cresciute con epitassia da fasci molecolari. I risultati della fotoluminescenza emessa nello strato depositato di GaAs sono analizzati e le sue proprietà ottiche sono collegate alle condizioni di crescita. Lo spostamento Stokes della riga di emissione dell'eccitone nel pozzo quantico è studiato in dipendenza delle varie condizioni di eccitazione. Si trova una considerevole diminuzione dello spostamento Stokes nel caso di eccitazione intensa e non risonante. Anche la fotoluminescenza estrinseca e la sua dipendenza dalla temperatura sono interpretate. Inoltre si mostra che gli effetti di temperatura su entrambi gli spettri del cristallo GaAs e del pozzo quantico chiariscono i ruoli del contributo eccitonico e delle transizioni interbanda.
    Abstract: Резюме Проведены измерения фотолюминесценции, фотолюминесценции возбуждения и козффициента отражения при различных температурах на образцах структур квантовых ям GaAs/Ga1−x Al x As, выраўенных с помощью эпитаксии молекулярного пучка. Анализируются некоторые данные по фотолюминесценции для буферных слоев GaAs для определения корреляции между оптическими свойствами и условиями выращивания. При различных условиях возбуждения исследуется сдвит Стокса линии испускания экситона на квантовых ямах. Наблюдается эаметное уменьшение сдвига Стокса в случае нерезонанснопо н интенсивного возбуждений. Также интерпретируются примесная фотолюминесценция и ее температурная зависимость. Показывается, что влияние температуры на обьемный спектр и спектр квантовых ям проясняет экситонные особенности и вклад межзонных переходов.
    Notes: Summary Measurements of photoluminescence, excitation photoluminescence and reflectance are performed at various temperatures on a series of GaAs/Ga1−x Al x As quantum well structures grown by molecularbeam epitaxy. The selective photoluminescence data of the GaAs buffer layers are analysed in order to correlate the optical properties with the growth conditions. The Stokes shift of the excitation emission line from quantum wells is investigated under various excitation conditions. A considerable decrease of the Stokes shift is observed in the case of nonresonant and intense excitations. Also the extrinsic photoluminescence, as well as its temperature dependence, are interpreted. In addition, the temperature effects on both the bulk and quantum well spectra are shown to clarify the excitation features and the contribution of the interband transitions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02450207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Allocative inefficiency properties of price-cap regulation (1993)
    Springer
    Journal of regulatory economics 5 (1993), S. 159-182 
    Details
    ISSN: 1573-0468
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract The paper deals with the argument that a price-cap regulated firm maximizing profits under the price-cap constraint will set prices that over time approach the Ramsey structure. My analysis explores the effects of price caps on the structure of prices. The results are in important aspects at variance with the claim of convergence to a Ramsey structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01065364
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Synthesis, X-ray crystal structure and cation binding properties of a tetrahomodioxacalix[4]arene tetraester (1991)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 10 (1991), S. 329-339 
    Details
    ISSN: 1573-1111
    Keywords: Calixarenes ; X-ray structure ; stability constants ; complexation ; phase transfer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Treatment ofp-t-butyltetrahomodioxacalix[4]arene with ethyl bromoacetate yields a tetraester derivative (4) whose crystal and molecular structure have been determined and whose ion binding properties have been assessed by phase transfer and stability constant measurements. Colorless transparent triclinic crystals (obtained from methoxyethanol) C62H84O14,a = 10.347(2),b = 11.583(2),c = 13.448(3) Å,α = 72.04(2),β = 86.50(2)°,γ = 81.23(2)°, space group $$P\bar 1$$ ,Z = 1, MoK α radiationλ = 0.70930 Å. Refinement was carried out using 2221 reflections withI 〉 1.5σ(I). The complexation properties resemble those of calix[6]arene hexaester (6), although weaker, with a preference for the larger alkali cations. Ca2+ and Ba2+; though not extracted, are more strongly complexed than alkali cations. Eu3+ is better complexed than Na+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01133318
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    On the dynamics of photochemical smog over the Swiss Middleland — Results of the first POLLUMET field experiment (1993)
    Springer
    Meteorology and atmospheric physics 51 (1993), S. 117-138 
    Details
    ISSN: 1436-5065
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Summary The Swiss Middleland is a 300×50 km large plain embedded between the Jura, whose highest elevations are between 1000 and 2000m MSL, and the Alps, whose highest peaks are about 400m MSL. Because this plain is the main residence area of Switzerland with a great variety of emission sources, it is also a location with high photosmog concentrations during the summer months. Within the framework of the Swiss POLLUMET (Air Pollution and Meteorology) programme, an initial summer smog field experiment was carried out during July 1990 with the participation of different research groups from Switzerland and Germany. The measurements showed that the ozone concentrations within the atmospheric boundary layer were remarkably variable. The highest concentrations in the upper mixed layer varied between 100 and 130 ppb. The background ozone concentration in the upper atmospheric boundary layer increased from day to day. However, a clear indication of long-range transport could not be found. Remarkable local and regional concentration differences are not only based on the complex structure of the large emission sources (highways, urban plumes). They are also the result of the interaction of convectively driven motion systems like slope and valley winds and mountain-plain circulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01080883
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Die Schwimmbewegungen der Tauchvögel (Blässhuhn und Pinguine) (1931)
    Springer
    Journal of comparative physiology 14 (1931), S. 682-708 
    Details
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00338010
    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...