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
    Relaxation in charge-transfer systems with very large tunnel splitting: A semiclassical stochastic approach (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 11176-11186 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Electron transfer in strongly coupled systems, appropriate to mixed-valence compounds, is studied to explore the competition between electronic coherence and dissipation. A set of stochastic equations is derived for a spin-boson Hamiltonian with large tunneling coupling matrix element (adiabatic regime) and strong system-bath-coupling. The bath dynamics is treated classically while the quantum character of the system is maintained. The bath dynamics is affected by the system dynamics, the effect being included by a mean-field description, valid for the adiabatic regime. Numerical solutions of the stochastic equations are presented and compared with exact quantum mechanical results. The numerical implementation of the method is straightforward and the long-time behavior of the system can be accessed. Analytic equilibrium solutions for the adiabatic regime are obtained, and we find good agreement between the long-time solution of the stochastic equations and these equilibrium solutions. We examine the dependence of the electronic population on the initial preparation of the bath and find that the proportion between oscillation (coherence) and decay (dissipation) is quite sensitive to this initial condition. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1326907
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Competitive evolution of the fine contrast modulation and CuPt ordering in InGaP/GaAs layers (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 3798-3803 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We use transmission electron microscopy to characterize the morphology of InGaP epitaxial layers grown by metal-organic vapor-phase epitaxy over misoriented GaAs (001) substrates, with a cutoff angle in a range from 0° to 25°. The occurrence of phase separation and CuPt-type ordered superstructures has been observed. The most ordered configuration has been found to appear in layers grown on 2° off substrates, and the strength of order decreases with increasing the misorientation angle beyond α=2°. Conversely, whereas the phase separation is less evident in the layer grown at 2°, the sample grown with a misorientation of 25° exhibits the most phase separated configuration. The completion between these two phenomena is discussed depending on the misorientation angle. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.363332
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Autoradiographic distribution of [3H]sumatriptan-binding sites in post-mortem human brain (1996)
    USA/Oxford, UK : Blackwell Science Ltd
    Cephalalgia 16 (1996), S. 0 
    Details
    ISSN: 1468-2982
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The anatomical distribution of [3H]sumatriptan-binding sites was analysed in brain tissue sections from 11 subjects. Relevant concentrations of [3H]sumatriptan-binding sites were seen in areas such as visual cortex〉locus niger〉globus pallidus〉layers IV-V of the frontal cortex〉subiculum〉entorhinal cortex〉nucleus tractus solitarius〉nucleus trigeminalis caudalis. This distribution of [3H]sumatriptan-binding sites in the human brain shows some differences when compared with that of 5HT1D receptors, confirming that, besides 5HT1D,sumatriptan also binds to 5HT1F receptor subtype. Some species differences are evident between the distribution of [3H]sumatriptan-binding sites in the human brain and that reported for guinea-pig and rat brains, emphasizing that caution is needed in extrapolating experimental data from animals to humans. Furthermore, these data help to explain some of the therapeutic actions of sumatriptan. The remarkable levels of binding found in areas such as nucleus tractus solitarius and nucleus trigeminalis caudalis suggest that in migraine attacks sumatriptan could exert its specific anti-emetic effects and, partly at least, induce analgesia by directly acting over these brain nuclei.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1468-2982.1996.1605317.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Isolated headache as the presenting clinical manifestation of intracranial tumors: a prospective study (1994)
    USA/Oxford, UK : Blackwell Science Ltd
    Cephalalgia 14 (1994), S. 0 
    Details
    ISSN: 1468-2982
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Isolated headache as the presenting clinical manifestation of intracranial tumors: a prospective study. Cephalalgia 1994;1'4:270-1. Oslo. ISSN 0333-1024We prospectively studied over two years the incidence of headache as the initial and isolated clinical manifestation of adult patients suffering from intracranial tumors (n = 183). Fifteen patients (8%) exhibited headache as their first and isolated clinical manifestation. Age, sex, neoplasm localization, or pathological diagnosis did not correlate with the presence of headache. Posterior fossa location and hydrocephalus, though not reaching statistical significance, were more frequent in patients who presented with headache as the first symptom. At the moment of diagnosis, 59 (31%) of the patients admitted to headache, though only I out of the 15 patients starting as headache still had this symptom as the only manifestation. From our experience in adults, isolated headache for longer than 10 weeks will only exceptionally be secondary to an intracranial neoplasm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1468-2982.1994.1404270.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Temperature control of a liquid helium cooled Eigler-style scanning tunneling microscope (2001)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 4393-4397 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: A procedure for operating an Eigler-style, low temperature scanning tunneling microscope (STM) at variable temperatures has been developed. A critical exchange gas pressure regime was found to allow for controlled variation of the STM temperature while it is encapsulated in a liquid helium Dewar. The sensitivity of various parameters to the ability to generate stable variable temperatures above 4 K is discussed. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1416108
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Thermal stability of InGaAs/InGaAsP quantum wells (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3760-3768 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report a cross investigation of the effect of interdiffusion on the photoluminescence and Raman spectra of a single quantum well of InGaAs (80 A(ring) wide) sandwiched between two large InGaAsP barriers. First, we investigate the blue shift of the recombination line (2 K) after annealing at 650 and 750 °C from 15 min to 2 h. We assume one single diffusivity coefficient for all atomic species (i.e., conservation of the lattice matching after annealing) and deduce the amount of intermixing through a model calculation. We find average diffusivity coefficients D=9.5×10−3 A(ring)2 s−1 and D=2×10−1 A(ring)2 s−1 at 650 and 750 °C, respectively. This agrees well with previous measurements reported for the parent system InGaAs/InP and supports an activation energy EA=2.54 eV. Next we investigate, on the same series of samples, the change in phonon frequency associated with the GaAs longitudinal-optical-like mode in the active InGaAs layer. To connect quantitatively the change in wave number with the change in arsenic composition, versus annealing sequence, one must use a carefully checked calibration curve. We show that the linear relationship Δy/Δω=4×10−2(cm) provides a satisfactory agreement with the results of our photoluminescence investigation. This gives for the amount of arsenic leaving the well Δy≈−5% per h1/2 at 650 °C and −20% per h1/2 at 750 °C, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.352882
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Rapid Photometric Determination of Cobalt in Presence of Iron (1953)
    s.l. : American Chemical Society
    Analytical chemistry 25 (1953), S. 1830-1832 
    Details
    ISSN: 1520-6882
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/ac60084a011
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Real time electron microscopy inspection of high temperature processes in W free standing wires (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 1077-1078 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: High temperature structural changes in a W wire are studied in situ by scanning electron microscopy. This is made possible by the microscopic size of the wire. Grain-boundary grooving and faceting are observed in real time. The constriction exhibits a strong thermal gradient (∼100 K μm−1) which is the driving force for the migration mechanisms responsible for the observed phenomena.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.108800
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Aquagenic keratoderma (2003)
    Oxford, UK : Blackwell Science Ltd
    Journal of the European Academy of Dermatology and Venereology 17 (2003), S. 0 
    Details
    ISSN: 1468-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Aquagenic keratoderma has been described as a transitory condition involving young females and defined clinically by the appearance of palmar lesions accentuated after immersion in water. According to previous case reports, these lesions are characterized histologically by hyperkeratosis and dilated eccrine ducts.Some aberration in the eccrine ducts has been suggested as a possible pathogenic mechanism. We report a new case in a female adolescent. With regard to the normal aspect of the epidermis in our case, the clinical changes should be ascribed to a structural alteration of the horny layer without any visible microscopy change or functional alteration of the stratum corneum involving the organism in the adolescence period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1468-3083.2003.00799.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    RESEARCH REPORT Clinical significance of Cloninger's classification in a sample of alcoholic Spanish men (1998)
    Oxford, UK : Carfax Publishing Limited
    Addiction 93 (1998), S. 0 
    Details
    ISSN: 1360-0443
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin , Psychologie
    Notizen: Abstract Aims. To evaluate Cloninger's classification in a sample of alcoholic Spanish men. Design. A crosssectional study was carried out on subjects diagnosed as alcoholics. Setting. Out-patient units specializing in the treatment of alcoholics and the psychiatry unit of a general hospital. Participants. One hundred and ninety-eight males diagnosed as alcoholics. The mean age was 44.4 11.6 years and 98% were from urban areas. Measurements. Participants were interviewed using the Structured Clinical Interview for DSMIII-R(SCID). They were classified using type 1 and type 2 criteria of Cloninger's classification. Findings. Only one-third of our sample could be classified by Cloninger's type 1 and type 2 criteria. Patients classified as belonging to type 2 had an earlier onset of regular drinking compared to type 1 patients. Type 2 subjects presented a higher percentage of alcohol-related problems as well as problems related to drugs other than alcohol and they also presented a higher percentage of antisocial personality disorder. No differences in alcoholism family history were found between the groups. Criteria showing the poorest discriminative ability between both groups were "failure to keep abstinent" and "benders lasting at least two days". Conclusions. Our results do not support Cloninger's etiological hypotheses for alcoholism. Cultural differences may be responsible for the different drinking patterns observed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1360-0443.1998.931939.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...