Bibliothek

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
Filter
  • 2000-2004  (4)
  • 1990-1994  (28)
  • 1975-1979  (9)
  • 1
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    Analytical chemistry 51 (1979), S. 69-72 
    ISSN: 1520-6882
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 5510-5517 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The polarized reflection spectra of single crystals of PDA-CPDO [poly-1-(N-carbazolyl)penta-1, 3-diyn-5-ol], which are π conjugated between the side groups and the main chain, have been measured in the photon energy region from 1.38 to 32 eV for the first time with a polarized synchrotron radiation source. Absorption spectra have been calculated using the Kramers–Kronig relation. Transitions in the visible absorption spectrum, which have been previously attributed to an interband transition in a similar polydiacetylene, have been found to be highly dichroic with respect to the direction along the polymer backbone. The absorption spectrum in this region reveals two broad (ΔE(approximately-greater-than)0.4 eV) peaks at 1.9 and 2.7 eV with an almost equal absorption coefficient of 7.5×104 cm−1. The spectral features in the range from 3 to 8 eV result from electronic transitions of the carbazolyl side groups. A single broad (ΔE∼10 eV) absorption band observed at 18 eV is due to either transitions of σ electrons to higher σ* or π* states of the carbazolyl group, or to ionization processes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 2039-2043 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The calculation of nuclear magnetic shieldings σ was performed for four first-row hydrides, i.e., HF, H2O, NH3, and CH4 using the finite-field many-body perturbation theory through second order in the electron correlation correction with London's gauge invariant atomic orbitals. The calculated isotropic shieldings σ¯ for the heavy atoms were larger than the experimental values. The rotational and vibrational correction for the σ¯ of the F atom in HF at 300 K was estimated to be −4.0 ppm.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 533-536 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The Fermi-contact contributions to the nuclear spin–spin coupling constants are computed for four first-row hydrides, i.e., HF, H2O, NH3, and CH4 using the finite perturbation many-body perturbation theory (FP-MBPT) through the second order in the electron correlation correction. The calculated values of JXH (X=O,N,C) yield reasonable results, but the calculation for JFH and the geminal JHH (in H2O, NH3, and CH4) presents too large values.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 2299-2304 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Electron correlation effects on the five mechanisms in the indirect nuclear spin–spin coupling tensors are computed for H 19F, H2 17O,14NH3,13CH4, H 35Cl, 33SH2, 31PH3, and 29SiH4. The five coupling mechanisms consist of Fermi-contact (FC), spin-dipole (SD), Fermi-contact and spin-dipole cross term (FC/SD), orbital paramagnetic (OP), and orbital diamagnetic (OD) terms. Electron correlation contributions through the second order are calculated by the finite-field many-body perturbation theory (FF-MBPT). The results show an extremely large contribution of the (FC/SD) cross term to the anisotropic part of the couplings. The FC contribution is dominant in the isotropic part, but the OP term is considerable in HF, HCl, and H2O. Electron correlation effects are large in the FC contribution. They are small, but not negligible, in the other terms except in the OD term.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 5999-5999 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 7404-7416 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The time-resolved spectroscopy in polydiacetylene single crystals (PDA-MADF {poly-1-[3-(methylamino)phenyl]-4-[3,5-bis(trifluoromethyl)phenyl]-1, 3-butadiyne}) on femtosecond and picosecond time scales was performed. The time dependence of the photoinduced reflectance change in PDA-MADF exhibits three components with lifetimes ∼200 fs, 1–2 ps, and (very-much-greater-than)200 ps. These components are assigned to the free 1Bu excitons, self-trapped excitons, and triplet excitons. From the excitation intensity dependence of the reflectance change, a significant role of bimolecular interactions between singlet excitons for the formation of triplet excitons is clarified. A model of the mechanism of triplet exciton formation after the creation of singlet excitons is proposed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 144 (2001), S. 0 
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background  The pathogenesis and aetiology of atopic dermatitis (AD) remain unclear. Establishment of suitable animal models should aid elucidation of the pathogenesis and development of therapy. Objectives  We focused on biophysical and biochemical parameters in the skin of NC/Nga Tnd mice to evaluate similarities to and differences from AD. Methods  Biophysical (transepidermal water loss and skin surface conductance) and biochemical parameters (ceramide contents and activity of ceramide-metabolizing enzymes) were measured in NC/Nga Tnd mice in which spontaneous dermatitis appeared under ambient laboratory conditions (ALC). Results  Biophysical parameters suggested impairment of water retention properties and barrier function. The amount of ceramide in NC/Nga Tnd mice under ALC decreased significantly. These dermatological features resembled those of AD, as did the clinical signs and histological changes. Conclusions  The results described here and previous immunological studies on AD suggest that the NC/Nga Tnd mouse may be a suitable model for certain aspects of AD.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 1069-1071 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Magneto-optical media using ultrathin Co/Pt and Co/Pd films were prepared on 2P (photopolymer) glass substrates with a double-layer disk structure. Thermomagnetic writing was successfully made in the magneto-optical disks by the relatively low laser power above 3 mW. The values of the C/N ratio were 50 dB for the Co/Pt disk and 45 dB for the Co/Pd disk at a bit length of 5 μm. Clear and regular bit domains were observed even in the shorter recorded bit length.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 1343-1345 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Reversible controllability of the third-order nonlinear optical activity has been demonstrated on a one-dimensional metal complex. Iodine penetration to a film sample causes disappearance of the d-p transition absorption band of the metal complex and remarkable decline of two-odd orders in the third-order nonlinear susceptibility. The deactivated optical nonlinearity was completely restored by removing iodine from the film with heating. The observed alterations in optical nonlinearities are mainly caused by the fluctuation of metal-metal interaction in the linear metal chain.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...