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
    facet.materialart.
    Unknown
    Curving and frustrating flatland (2004)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2004-10-02
    Description: Two polymer chains that occupy equal volumes when covalently linked together at one end self-assemble into an alternating lamellar morphology that has a characteristic period dictated by the molecular weight. When such copolymers are confined within alumina membranes that have cylindrical pores with diameters comparable to the repeat period, the interaction of the blocks with the confining walls and the imposed curvature induces a morphological transformation to relieve the constraints. Here, we show a lamella-to-toroid transition, captured through the dissolution of the surrounding membrane.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shin, Kyusoon -- Xiang, Hongqi -- Moon, Sung In -- Kim, Taehyung -- McCarthy, Thomas J -- Russell, Thomas P -- New York, N.Y. -- Science. 2004 Oct 1;306(5693):76.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Polymer Science and Engineering, Silvio O. Conte National Center for Polymer Research, University of Massachusetts, Amherst, MA 01003, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15459380" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Helical polyacetylene heavily doped with iodine: Magnetotransport (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 114 (2001), S. 7222-7227 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The magnetoconductivity of two kinds of iodine doped helical polyacetylene, R- and S-polyacetylene, were investigated to understand the effect of the intrafibril and the interfibrillar interaction in the polyacetylene system. The zero-field resistivity ratio, ρr=ρ(1.2 K)/ρ(300 K), is comparable to that of stretch-oriented high-density polyacetylene film, which indicates the partial alignment of chains inside a polymer fiber. At low magnetic fields, the small negative component of magnetoconductivity (positive magnetoresistance) was observed and its magnitude increases as the ρr value increases. In the high field region, the magnetoconductivity is positive and it clearly shows the linear dependence on the magnetic field up to H=30 T. The linear field dependence of magnetoconductivity is different from what is expected in the three-dimensional localization-interaction picture. For the same ρr value samples, the magnitude of negative magnetoconductivity of S-polyacetylene is much bigger than that of R-polyacetylene, which could be attributed to the difference in the degree of helicity determining the strength of interfibrillar interaction. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1358837
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Structural, electrical, and optical properties of SnO2 nanocrystalline thin films grown on p-InSb (111) substrates (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 175-180 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: SnO2 thin films were grown on p-InSb (111) substrates by radio-frequency magnetron sputtering at low temperature. Atomic force microscopy images showed that the root mean square of the average surface roughness of the SnO2 films grown on the InSb (111) substrates with an Ar/O2 flow rate of 0.667 and at a temperature of 200 °C had a minimum value of 2.71 nm, and x-ray diffraction and transmission electron microscopy (TEM) measurements showed that these SnO2 thin films were polycrystalline. Auger electron spectroscopy and bright-field TEM measurements showed that the SnO2/p-InSb(111) heterointerface was relatively abrupt. High-resolution TEM measurements revealed that the SnO2 films were nanocrystalline and that the grain sizes of the nanocystalline films were below 6.8 nm. The capacitance–voltage measurements at room temperature showed that the type and the carrier concentration of the nominally undoped SnO2 film were n type and approximately 1.67×1016 cm−3, respectively, and the current–voltage curve indicated that the Au/n-SnO2/p-InSb diode showed tunneling breakdown. Photoluminescence spectra showed that peaks corresponding to the donor acceptor pair transitions were dominant and that the peak positions did not change significantly as a function of the measured temperature. These results indicate that the SnO2 nanocrystalline thin films grown on p-InSb (111) substrates at low temperature hold promise for new kinds of potential optoelectronic devices based on InSb substrates, such as superior gas sensors and high-efficiency solar cells. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1372159
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Existence of a CuAu–I-type ordered structure in lattice-mismatched InxGa1−xAs/InyAl1−yAs multiple quantum wells (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 2503-2505 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Selected area electron diffraction pattern (SADP) and transmission electron microscopy (TEM) measurements were carried out to investigate the ordered structures in lattice-mismatched InxGa1−xAs/InyAl1−yAs multiple quantum wells (MQWs). The SADP showed two sets of extra spots with asymmetrical intensity, and the high-resolution TEM image showed doublet periodicity in the contrast of the (001) lattice planes. The results of the SADP and the TEM measurements showed that a CuAu–I-type ordered structure was observed near the lattice-mismatched InxGa1−xAs/InyAl1−yAs heterointerfaces. This CuAu–I-type ordered structure had an antiphase boundary in the periodically regular InxGa1−xAs/InyAl1−yAs lattice-mismatched region. The existence of a CuAu–I-type ordered structure in InxGa1−xAs/InyAl1−yAs MQWs might originate from the lattice mismatch between the InxGa1−xAs and the InyAl1−yAs layers. These results provide important information on the microstructural properties for improving operating efficiencies in long-wavelength optoelectronic devices, such as strain compensated electroabsorption modulators utilizing lattice-mismatched InxGa1−xAs/InyAl1−yAs MQWs. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1337917
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Biphasic intracellular expression of Staphylococcus aureus virulence factors and evidence for Agr-mediated diffusion sensing (2003)
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 49 (2003), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Staphylococcus aureus invades a variety of mammalian cells and escapes from the endosome to multiply in the cytoplasm. We had previously hypothesized that the molecular events leading to escape of S. aureus from the endosome involved the Agr virulence factor regulatory system. In this report we demonstrate that temporal changes in intracellular activation of the Agr regulon correlates with expression of membrane active toxins. Also, the initial expression of Agr by even small numbers of staphylococci resulted in the permeabilization of the endosomal membrane and the eventual escape of bacteria into the cytoplasm by 3 h post invasion. After Agr downregulation, a second peak of expression coincided with increased permeability of the host cell membrane. In contrast to the parental strain, an Agr-mutant was unable to escape into the cytoplasm and was observed in intact endosomes as late as 5 h post invasion. These data provide evidence that staphylococcal virulence factor production during invasion of host cells is mediated by an Agr-dependent process that is most accurately described in the context of diffusion sensing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2958.2003.03618.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Emergent excitations in a geometrically frustrated magnet (2002)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 418 (2002), S. 856-858 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Frustrated systems are ubiquitous, and they are interesting because their behaviour is difficult to predict; frustration can lead to macroscopic degeneracies and qualitatively new states of matter. Magnetic systems offer good examples in the form of spin lattices, where all interactions between ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/nature00964
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Effects of Si-dose on defect-related photoluminescence in Si-implanted SiO2 layers (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 1851-1854 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Si ions were implanted into 100-nm-thick SiO2 layer thermally grown on crystalline Si at an energy of 55 keV with various doses ranging from 1×1014 to 1×1017 Si/cm2 at room temperature. Si ions go through the interface between SiO2 layer and Si substrate generating defects in SiO2 layer and Si substrate as well. Defect-related phenomena were characterized by photoluminescence (PL) and electron spin resonance (ESR) measurements. The PL experiment shows that there exists a dose window for a maximum intensity of luminescence related to radiative defects, while the ESR exhibits that nonradiative defects change from E′ centers to Pb centers as the dose increases. It is considered that the intensity is controlled by the density ratio of radiative to nonradiative defects induced by ion implantation. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1305909
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The GMR effect in annealed Co/Co2TiSn thin films (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 4861-4863 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The giant magnetoresistance (GMR) effect of Co/Co2TiSn thin films with two magnet phases was observed in samples annealed in vacuum and N2(10% H2) gas atmospheres. The perpendicular magnetization curve of the films have the hysteresis loop of a typical bubble domain material. Various features of electrical resistivity at room temperature of the annealed films suggest GMR behavior. The resistivity decreases with increasing field and saturates at a field of around 2 kOe which is the same as in-plane saturation field from magnetization measurements. In the film annealed in N2 gas, the magnetoresistivity, δρ(H), is 1.43×10−7 Ω cm and the GMR is 0.18%. In the film annealed in vacuum, the δρ(H) and GMR are about 3.3×10−8 Ωcm and 0.12%, respectively. The GMR effect in annealed Co/Co2TiSn films indicates the scattering of spin polarized conduction electrons because of the antiparallel exchange coupling at the phase boundary between the two magnetic phases. The scattering process of conduction electrons at the phase boundary was modeled in relation to the magnetization process. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.373183
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Electronic parameters of the two-dimensional electron gas in modulation-doped single quantum wells due to an embedded deep step layer (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 2649-2652 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The Shubnikov–de Haas (S–dH) measurements at 1.5 K clearly demonstrated the existence of a two-dimensional electron gas (2DEG) in the modulation-doped Al0.25Ga0.75As/InyGa1−yAs/GaAs single and step quantum wells, and the fast Fourier transformation results for the S–dH data clearly indicated the electron occupation of one subband in the asymmetric single and step quantum wells. While the electron carrier density of the 2DEG in the step quantum well was larger than that in the single quantum well due to the larger conduction-band discontinuities, the mobility of the 2DEG in the step quantum well was smaller than that in the single quantum well because of the interface scattering resulting from the embedded step well. The electron effective mass in the step quantum well was smaller than that in the single quantum well, which was consistent with a smaller mass of the embedded deep step layer. The electronic subband energy, the energy wave function, and the Fermi energy in the InyGa1−yAs step quantum wells were calculated by using a self-consistent method taking into account exchange-correlation effects together with strain and nonparabolicity effects. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1344222
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Spontaneous Hall effect in amorphous Tb–Fe and Sm–Fe thin films (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 7212-7214 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The spontaneous Hall effect in amorphous Tb–Fe and Sm–Fe thin films, which possess excellent magnetic softness, is investigated to seek a possibility of practical applications of these thin films. The resistivity of Tb–Fe thin films ranges from 180 to 250 μΩ cm as the Tb content varies from 35 to 46 at. %. Tb–Fe thin films show negative Hall resistivity ranging from −7.3 to −5.0 μΩ cm in the same composition range, giving the normalized resistivity ratio from −4.1% to −2.0%. On the other hand, the resistivity of Sm–Fe thin films ranges from 150 to 166 μΩ cm as the Sm content varies from 22 to 31 at. %. Sm–Fe thin films show positive Hall resistivity which varies from 7.1 to 2.8 μΩ cm in the same composition range, giving the normalized resistivity ratio from 4.8% to 1.7%. Between the two different sets of samples, Tb–Fe thin films with perpendicular anisotropy are considered to be more suitable for practical applications, since saturation is reached at a low magnetic field. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1357117
    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...