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
    Phase formation in the interfacial reactions of ultrahigh vacuum deposited titanium thin films on (111)Si (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 5918-5925 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Phase formation in the interfacial reactions of ultrahigh vacuum deposited Ti thin films on (111)Si has been studied by in situ reflected high energy electron diffraction (RHEED) and transmission electron microscopy (TEM). In situ RHEED and high resolution TEM data showed unambiguously that there is considerable intermixing of Ti and Si atoms during Ti deposition. Ti5Si3 was found to be the first nucleated phase followed by Ti5Si4 and TiSi. Ti5Si3, Ti5Si4, TiSi, and C49-TiSi2 along with a-interlayer were found to form in samples annealed at 475 °C for 30 and 60 min. Ti5Si4 was the first silicide phase to disappear followed by Ti5Si3 then TiSi. In samples annealed at 700 °C for 10 min, C54-TiSi2 started to appear. To understand the thermodynamic origin of the phase formation, metastable free energy diagrams at 450–600 °C have been constructed. Ti5Si3 and C49-TiSi2 were found to have the highest and lowest driving force, respectively. On the other hand, Ti5Si4 has the lowest interface energy. The sequence of formation and disappearance of silicide phases is discussed accordingly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.350441
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Precise determination of aluminum content in AlGaAs (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 4877-4882 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The Al composition of AlGaAs has been determined by four methods: high-resolution transmission electron microscopy (HRTEM), reflection high-energy electron diffraction (RHEED), photoluminescence (PL), and double-crystal x-ray diffraction (DCXRD). HRTEM is direct and the most accurate method because it does not involve any formula or extrapolation. Using the result obtained from HRTEM as a standard, we have calibrated the results from other methods. RHEED intensity oscillation is found to be accurate and reliable, if the growth conditions are correctly chosen. Comparing the PL results with those determined from HRTEM and RHEED, we suggest three formulas to determine the Al contents at different temperatures. We also proposed a polynomial to determine the Al concentration using the DCXRD measurement.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.349030
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Identification of the first nucleated phase in the interfacial reactions of ultrahigh vacuum deposited titanium thin films on silicon (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 463-465 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The first nucleated phase in ultrahigh vacuum deposited Ti thin films on silicon has been unambiguously identified utilizing high-resolution transmission electron microscopy (HREM) in conjunction with optical diffractometry. Ti5Si3 was found to form first at the interface of the Ti overlayer and the amorphous interlayer. For plan-view specimens of the samples annealed at 450 °C for 30 min, 1 and 2 h, all 15 silicide diffraction rings corresponding to interplanar spacings longer than 0.098 nm could be attributed to Ti5Si3. Ti5Si3 was also the only silicide phase that could match the symmetry and lattice spacings of the HREM images. The observation is consistent with a kinetic model which predicts that the crystalline phase with composition and structure nearest to that of the amorphous interlayer will be first nucleated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.104608
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Aligned and twinned growth of α-Fe thin films on atomically cleaned (111)Si at room temperature (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 1603-1605 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Epitaxial α-Fe thin films have been grown on atomically cleaned (111)Si at room temperature under ultrahigh vacuum condition. The α-Fe epitaxy on (111)Si was analyzed by transmission electron microscopy (TEM) to be predominantly of twinned epitaxy with a small fraction of epitaxy being aligned with respect to the substrate. High resolution TEM showed that the interface between the epitaxial iron thin film and Si substrate is atomically flat with the presence of a low density of atomic steps. Interfacial dislocations were found to be of edge type with 1/2〈11¯0(approximately-greater-than) Burgers vectors. The average spacing of interfacial dislocations was found to be close to the theoretically predicted value.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.108599
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Simultaneous occurrence of multiphases in interfacial reactions of ultrahigh vacuum deposited Ti thin films on (111)Si (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 2460-2462 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: High resolution transmission electron microscopy in conjunction with optical diffractometry have been applied to identify the formation of an amorphous interlayer as well as to detect the presence of Ti5Si3, Ti5Si4, TiSi, and C49-TiSi2 in the interfacial reactions of ultrahigh vacuum (UHV) deposited Ti thin films on atomically clean (111)Si. The discovery of the formation of an amorphous interlayer and as many as four different silicide phases in the initial stages of interfacial reactions of UHV deposited Ti thin films on silicon by high resolution techniques necessitates a modification of the existing theory of the silicide formation in thin-film reactions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.105995
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Specific Activation of Human Peripheral Blood γ/δ+ T Lymphocytes by Sonicated Antigens of Mycobacterium tuberculosis: Role In Vitro in Killing Human Bladder Carcinoma Cell Lines (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 38 (1993), S. 0 
    Details
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Tumour regression induced in cancer patients hy local instillation of Bacillus Calmette-Guérin (BCG) into the hiadder has been considered to be mainly mediated by activated cellular immunity and inflammatory reactions. In the present study we investigated the cytotoxicity of T cells bearing γ/δ T-cell receptors (γ/δ+ T cells) against bladder carcinoma cells in vitro. Long-term cultured γ/δ+ T-cell lines from peripheral blood lymphocytes of healthy donors were established by stimulation with sonicated cell wall-associated antigens of Mycobacterium tuberculosis (SMA). These γ/δ+ T cells lack the natural killer (NK) markers CD16 and CD56, as determined by flow cytometry. The SMA-specific γ/δ+ T cells exhibited profound cytotoxicity against two NK-resistant bladder tumour cell lines as well as against NK-sensitive tumour eells in a non-major histocompatibility complex-restricted manner. The pattern of tumour cells killed by γ/δ+ T cells differed significantly from those of NK cells and lymphokine-activated killer LAK cells. Furthermore, we tested the effects of recombinant human cytokines. including interleukin (IL)-l, IL-2, IL-4, IL-6, interferon (IFN)-γ and tumour necrosis factor (TNE), on γ/δ+ T-cell-medlated cytotoxicity. It was shown that the addition of recombinant TNF in co-incubation could augment γ/δ+ T-cell-mediated killing of two bladder tumour cell lines, but not of cells of the erythroleukaemia eell line K562. Based on these results it was concluded that mycobacterial antigens could specifically activate resting γ/δ+ T cells. The cytotoxicity of γ/δ+ T cells against bladder tumour cells and its selective enhancement by TNF may bean important mechanism involved in bladder tumour regression induced by intravesical instillation of BCG.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3083.1993.tb01720.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Macrophage-Stimulating Protein and RON Receptor Tyrosine Kinase: Potential Regulators of Macrophage Inflammatory Activities (2002)
    Oxford, UK : Blackwell Science Ltd
    Scandinavian journal of immunology 56 (2002), S. 0 
    Details
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Macrophage-stimulating protein (MSP) is a serum protein belonging to the plasminogen-related growth factor family. The specific receptor for MSP is the RON (recepteur d'origine nantais) receptor tyrosine kinase – a member of the MET proto-oncogene family. Activation of RON by MSP exerts dual functions on macrophages. The stimulatory activities include the induction of macrophage spreading, migration and phagocytosis. However, MSP also inhibits lipopolysaccharide (LPS)-induced production of inflammatory mediators, including inducible nitric oxide and prostaglandins. These suppressive effects are mediated by RON-transduced signals that block LPS-induced enzymatic cascades that activate nuclear factor kappa-B (NFκB) pathways. Recent in vivo studies demonstrated that inactivation of the RON gene results in increased inflammatory responses and susceptibility to LPS-induced septic death in mice, suggesting that RON expression is required for attenuating the extent of inflammatory responses in vivo. Thus, MSP and RON are potential regulators that control macrophage activities during bacterial infection in vivo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-3083.2002.01177.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Effect of temperature and flux concentration on soldering of base metal (2000)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 27 (2000), S. 0 
    Details
    ISSN: 1365-2842
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The present study used the acoustic emission (AE) technique to evaluate interactions among soldering temperature, flux treatment, and the resultant ultimate tensile strength (UTS). Scanning electron microscopy (SEM) was used to examine fracture surfaces of the solder joints. Specimens were cast from removable partial denture alloy and then placed in a jig with a gap distance of 1·0 mm. A high-frequency soldering machine with an optical pyrometer was used for soldering at 1150°C and 1200°C, respectively. The flux concentrations were 67% and 75%. The soldered specimens were subjected to tensile test at a crosshead speed of 0·05 mm/min. During testing, acoustic emissions in the frequency range of 100–1200 kHz were collected, filtered, recorded, and processed by a sensing device. The results were analysed by anova and Tukey LSD test. UTS at different temperatures showed no significant difference according to either mechanical or acoustic results. But in the 1200°C group, the UTSs and AE counts showed significant differences (P〈0·05) at both flux concentrations. SEM showed that the 1200C group had better dendritic crystal structure than did the 1150°C group. In the 1200°C group specimens with 67% flux had fewer flux inclusion bodies and dendritic crystals than did specimens with 75% flux. The 75% flux subgroup produced high-amplitude (60–70 dB) acoustic signals within the elastic deformation zone, while the 67% flux subgroup produced similar signals within the plastic deformation zone, either beyond the 0·2% yield point or before fracture.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2842.2000.00614.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Internal Pair Conversion (1948)
    [s.l.] : Nature Publishing Group
    Nature 162 (1948), S. 264-264 
    Details
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] WHEN a γ-quantum, emitted from the nucleus of a radioactive atom, is absorbed by the same atomic system, an ordinary electron and a positron may be liberated if the energy of the γ-quantum is greater than 2mc2. This effect has been calculated by Jaeger and Hulme1 ...
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1038/162264b0
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Synthesis and structure of diaquabis(glycolato-O,O'')germanium(IV) (1993)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 49 (1993), S. 244-246 
    Details
    ISSN: 1600-5759
    Quelle: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1107/S0108270192006218
    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...