Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Effects of mechanical stress on the volume phase transition of poly(N-isopropylacrylamide) based polymer gels (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 7640-7645 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The effects of mechanical stress on the volume phase transition of a poly(N-isopropylacrylamide) (PNIPA) gel as well as a copolymer gel composed of N-isopropylacrylamide (NIPA) and sodium acrylate (SA) were investigated in the relatively low stress region. The PNIPA gel without elongational stress showed the behavior close to the second order phase transition. The character of the first order transition became clear under tension, and the transition temperature increased with increasing applied stress. Similar behavior was observed for the NIPA-SA copolymer gel, but the copolymer gel showed the first order transition in the whole stress range investigated. The thermodynamical linear region, where the transition temperature varies linearly with applied stress, was narrower than the mechanical linear region determined by the stress–strain relation of the gels. The change in the transition behavior by the application of the mechanical stress originated chiefly from the volume change in the gels by the applied mechanical stress. It was found that the curve of the transition temperature against applied stress corresponds to the phase boundary between the swollen and collapsed phases for the gels. On the basis of the experimental data, a phenomenological model describing the volume phase transition of the polymer gels is proposed in the frame of the Landau-type free energy expression. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1312273
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Magnetotransport properties of MnAs/GaAs/MnAs ferromagnet/semiconductor trilayer heterostructures (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 6695-6697 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We have succeeded in growing MnAs/GaAs/MnAs ferromagnet/semiconductor trilayer heterostructures on GaAs(111)B substrates by molecular-beam epitaxy. Double-step features were observed in magnetization characteristics due to the difference in coercive force between the top and bottom MnAs layers. Magnetoresistance (MR) curves in current-in-plane geometry showed the spin-valve effect, which was caused by the change of the magnetic alignment of the two ferromagnetic MnAs layers from parallel to antiparallel orientation. Temperature dependence of the MR was also investigated. We infer that the positive temperature coefficient of the MR by the spin-valve effect suggests the heat (carrier) induced interlayer exchange coupling. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.372811
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Chemical vapor deposition diamond window as vacuum and tritium confinement barrier for fusion application (2000)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 71 (2000), S. 4139-4143 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: A pressure resistant polycrystalline chemical vapor deposition (CVD) diamond disk for a microwave window is used for a vacuum and a tritium confinement boundary in fusion applications. A pressure test of a CVD diamond window disk (2.25 mm in thickness and 100 mm in diameter) was carried out. It was demonstrated that the diamond window tolerated 1.0 MPa (10 atm) in the plenum. The displacement of the window center for both the growth and the nucleation side on the unpressurized side is 40±1 and 41±1 μm, respectively, at the pressure of 1.0 MPa, and these values agree well with those calculated. No damage in the disk and the braze, and no vacuum leakage in the assembly was observed. This result demonstrates that the diamond window assembly could tolerate up to 1.45 MPa. It was experimentally proved that the diamond window satisfied the safety requirement of 0.5 MPa resistance for the vacuum and the tritium confinement boundary of an International Thermonuclear Experimental Reactor. The design prospect for the diamond window of the electron cyclotron heating and current drive system is also discussed, based on the stress analysis using the ABAQUS code. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1313799
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Growth of aligned carbon nanotubes by plasma-enhanced chemical vapor deposition: Optimization of growth parameters (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 1529-1533 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Direct-current plasma-enhanced chemical vapor deposition (CVD) with mixtures of acetylene and ammonia was optimized to synthesize aligned carbon nanotubes (CNTs) on Co- or Ni-covered W wires with regard to wire temperature, wire diameter, gas pressure, and sample bias. A phase diagram of CNT growth was established experimentally in this optimization process. It was revealed by transmission electron microscopy that Co-catalyzed CNTs encapsulated a Co carbide nanoparticle at their tip, disagreeing with a previous report that Co particles were located at the base of CNTs CVD grown on Co-covered Si substrates [C. Bower et al., Appl. Phys. Lett. 77, 2767 (2000)]. This leads to the conclusion that the formation mechanism of aligned CNTs depends significantly on the catalyst support material as well as the catalyst material itself. Since the sample bias strongly affected the morphology of CNTs, the selective supply of positive ions to CNT tips was possibly responsible for the alignment of growing CNTs. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1382848
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Fast ignitor research at the Institute of Laser Engineering, Osaka University : The 42nd annual meeting of the division of plasma physics of the American Physical Society and the 10th international congress on plasma physics (2001)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 8 (2001), S. 2268-2274 
    Details
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The physics element relevant to the fast ignitor in inertial confinement fusion has been extensively studied. Laser-hole boring with enormous photon pressures into overcritical densities was experimentally proved by density measurements with XUV laser probing. Ultra-intense laser interactions at a relativistic parameter regime were studied with a 50-TW glass laser system and a 100-TW glass laser system synchronized with a long pulse laser system. In the study of relativistic laser beam propagation in a 100-μm scale-length plasma, a special propagation mode (super-penetration mode) was observed, where the beam propagated into overdense regions close to the solid target surface. At the super-penetration mode, 20% of the laser energy converted to energetic electrons toward the target inside, while the coupling efficiency was 40% without the long scale-length plasmas. The high-density energetic electron transport and heating of solid material was also studied, indicating beamlike propagation of the energetic electrons in the solid target and effective heating of solid density ions with the electrons. Based on these basic experimental results, the heating of imploded plasma by short-pulse-laser light with three different ways of injecting the heating pulse has been studied. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1352598
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Studies of ultra-intense laser plasma interactions for fast ignition : The 41st annual meeting of the division of plasma physics of the american physical society (2000)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 2014-2022 
    Details
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Laser plasma interactions in a relativistic parameter regime have been intensively investigated for studying the possibility of fast ignition in inertial confinement fusion (ICF). Using ultra-intense laser systems and particle-in-cell (PIC) simulation codes, relativistic laser light self-focusing, super hot electrons, ions, and neutron production, are studied. The experiments are performed with ultra-intense laser with 50 J energy, 0.5–1 ps pulse at 1053 nm laser wavelength at a laser intensity of 1019 W/cm2. Most of the laser shots are studied under preformed plasma conditions with a 100 μm plasma scale length condition. In the study of laser pulse behavior in the preformed plasmas, a special mode has been observed which penetrated the preformed plasma all the way very close to the original planar target surface. On these shots, super hot electrons have been observed with its energy peak exceeding 1 MeV. The energy transport of the hot electrons has been studied with making use of Kα emissions from a seeded metal layer in planar targets. The details of ion acceleration followed by beam fusion reaction have been studied with neutron spectrometers. Laser ponderomotive force self-focusing and hot electron generation have been applied to a compressed core to see the effect of heating by injecting 12 beams of 100 ps, 1 TW pulses. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.874023
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Interface ferromagnetism in oxide superlattices of CaMnO3/CaRuO3 (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 1324-1326 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Oxide superlattices composed of antiferromagnetic insulator layers of CaMnO3 (10 unit cells) and paramagnetic metal layers of CaRuO3 (N unit cells) were fabricated on LaAlO3 substrates by pulsed-laser deposition. All the superlattices show ferromagnetic transitions at an almost identical temperature (TC∼95 K) and negative magnetoresistance below TC. Each magnetization and magnetoconductance of the whole superlattice at 5 K is constant and independent of CaRuO3 layer thickness when normalized by the number of the interfaces between CaMnO3 and CaRuO3. These results indicate that the ferromagnetism shows up only at the interface and is responsible for the magnetoresistance. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1398331
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Carbon nanotubes as electron source in an x-ray tube (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 2578-2580 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Field emitters comprised of aligned carbon nanotubes are shown to be promising as a primary electron source in an x-ray tube working in a nonultrahigh vacuum ambience. At a pressure of 2×10−7 Torr, the nanotube emitters continue to emit electrons for more than 1 h, and yield better resolved x-ray images than do thermionic emitters, independently of whether the sample is biological or nonbiological. The near-uniformity in energy distribution of electrons emitted from carbon nanotubes might be related to the improved image quality in the field-emission mode. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1367278
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Acoustic characteristics of sounds from temporomandibular joints with and without effusion: an MRI study (2002)
    Oxford UK : Blackwell Science Ltd
    Journal of oral rehabilitation 29 (2002), S. 0 
    Details
    ISSN: 1365-2842
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Joint effusion has been associated with temporomandibular joint (TMJ) pain but can only be diagnosed by magnetic resonance imaging (MRI). For screening of patients with suspected effusion a simple and less expensive method would be desirable. We recorded joint sounds during jaw opening and closing movement from 34 TMJs with internal derangement (ID). Seventeen joints had joint effusion seen on MRI. Spectrograms of the sounds were displayed as waterfall plots showing profiles of the consecutive Hamming windows. If the profiles were similar, as judged by initial evaluation, the displayed pattern was classified as stable. If some profiles were distinctly deviating in their pattern, this was classified as unstable. Joints with effusion showed unstable sound pattern more often than joints without effusion (P 〈 0·001). It was concluded that TMJ sound analyses have a potential to identify joints with effusion based on their unstable sound pattern.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2842.2002.00844.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Angiosarcoma of the scalp: absence of vascular endothelial cadherin in primary and metastatic lesions (2001)
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 144 (2001), S. 0 
    Details
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: A 73-year-old man with angiosarcoma of the scalp died about 1 year after disease onset, despite systemic and topical administration of recombinant interleukin-2. Histopathology showed typical changes of endothelial cells with very sparse lymphocytic infiltration into the tumour. An autopsy revealed that the primary site penetrated cranial bone and invaded vertically into the subarachnoid space. Multiple metastases to lung, chest wall, vertebrae and ribs were also found. On immunofluorescence staining, the expression of vascular endothelial cadherin, which is present in normal endothelium, was absent from both primary and metastatic sites. This may have promoted local invasion and metastasis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2133.2001.04032.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...