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
Filter
  • Artikel: DFG Deutsche Nationallizenzen  (22)
  • 2000-2004  (8)
  • 1985-1989  (14)
Datenquelle
  • Artikel: DFG Deutsche Nationallizenzen  (22)
Materialart
Erscheinungszeitraum
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Observation of free excitons in room-temperature photoluminescence of GaAs/AlGaAs single quantum wells (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 675-677 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Observation of free excitons is reported in room-temperature photoluminescence of nominally undoped GaAs/AlGaAs single quantum wells grown by molecular beam epitaxy. A comparative study with parallel-conduction photocurrent spectroscopy shows that a sharp luminescence peak with a linewidth of 14 meV observed for the 6.1-nm-wide well coincides within 2 meV with the n=1 heavy-hole free-exciton resonance line at excess carrier densities less than 1017 cm−3. Excitonic decay channels dominate the luminescence spectrum even at room temperature as a result of quantum confinement effects, although photogenerated carriers are also provided for photocurrents by exciton dissociations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.99847
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Linear polarization effects in anisotropic photoemission from GaAs/AlAs short-period superlattices (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 1717-1719 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: By investigating the linear polarization dependence of intrinsic emissions from undoped GaAs/AlAs short-period superlattices at room temperature, it is shown that a dominating peak observed in the normal emission spectra is due to the free-carrier recombination associated with the lowest electron to mixed-hole subbands with an unexpectedly large light-hole character instead of with the lowest electron to pure heavy-hole subbands expected in an ideal superlattice. Origins of the extensive valence-band mixing in the synthesized superlattices are discussed in relation to microscopic fluctuations in the layer thicknesses observed in the transmission electron microscope lattice image.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.98554
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Capture of photoexcited carriers by a laser structure (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 2646-2648 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The capture of photoexcited carriers in different laser structures is investigated by subpicosecond luminescence spectroscopy. The capture time at 20 and 80 K is monitored by the decay of the luminescence of the confinement layers. It is found to range between 2 and 3 ps for both linear and parabolic grading, and to be much longer in nongraded structures. The improvement of the capture in the case of graded structures is due to the quasi-electric field experienced by the carriers, and might allow the devices to run at much higher frequencies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.101962
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Carrier trapping in single quantum wells with different confinement structures (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 226-228 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The trapping efficiency and trapping dynamics of photoexcited carriers in GaAs/AlGaAs single quantum wells with different confinement structures are examined at low temperature by means of picosecond luminescence as well as photoluminescence excitation spectroscopy. The trapping efficiency is 100% only in graded-index separate confinement heterostructures with a linear band-gap profile. The lower trapping efficiency of other confinement structures is due to radiative and nonradiative recombination in the confinement layers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.98456
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Highly sensitive photocurrent spectroscopy of resonant couplings between GaAs/AlAs superlattice Stark ladders and GaAs single quantum well states (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 7927-7930 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We have investigated interactions between the localized states in a single quantum well (SQW) embedded in the center of a superlattice (SL) and the Wannier–Stark ladder states in the SL by low temperature photocurrent (PC) spectroscopy using numerical differentiation for an analysis of the measured PC spectra. It is found that the PC spectra show drastic changes of transition energies and oscillator strengths due to resonances between the SQW localized states and the extended SL Stark ladder states. We demonstrate high sensitivity of PC spectroscopy by introducing the differentiated spectra and gray-scale representation. Based on transfer matrix calculations of the eigen energies and wave function overlap integrals, the observed anticrossings and delocalization phenomena are rigorously explained. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.373476
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Temperature dependence of electroluminescence intensity of green and blue InGaN single-quantum-well light-emitting diodes (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 3723-3725 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Temperature dependence of electroluminescence (EL) spectral intensity of the super-bright green and blue InGaN single-quantum-well (SQW) light-emitting diodes has been studied over a wide temperature range (T=15–300 K) under a weak injection current of 0.1 mA. It is found that when T is slightly decreased to 140 K, the EL intensity efficiently increases, as usually seen due to the improved quantum efficiency. However, with further decrease of T down to 15 K, it drastically decreases due to reduced carrier capture by SQW and trapping by nonradiative recombination centers. This unusual temperature-dependent evolution of the EL intensity shows a striking difference between green and blue SQW diodes owing to the different potential depths of the InGaN well. The importance of efficient carrier capture processes by localized tail states within the SQW is thus pointed out for enhancement of radiative recombination of injected carriers in the presence of the high-density dislocations. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1421416
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Photoluminescence line shape of excitons in GaAs single-quantum wells with and without heterointerface ordering (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 1488-1491 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The photoluminescence line shape of excitons at low temperatures is investigated in GaAs single-quantum wells grown by molecular-beam epitaxy with and without intentional heterointerface ordering. From the study of the excitation density dependence in the range between 1015 and 1017 cm−3, it is found that the inhomogeneous linewidth is significantly affected by band-filling effects of intrinsic defect states spatially localized in the wider wells. In the sample with heterointerface ordering the band-filling effects are directly identified by observation of saturation of the localized excitonic emissions, which are split as a result of increased spatial coherence of the excitonic states.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.344406
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Peripheral injection of risperidone, an atypical antipsychotic, alters the bodyweight gains of rats: reply (2003)
    Oxford, UK : Blackwell Science Pty
    Clinical and experimental pharmacology and physiology 30 (2003), S. 0 
    Details
    ISSN: 1440-1681
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1440-1681.2003.t01-2-03854.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Lobular endocervical glandular hyperplasia is a metaplastic process with a pyloric gland phenotype (2001)
    Oxford UK : Blackwell Science Ltd
    Histopathology 39 (2001), S. 0 
    Details
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Lobular endocervical glandular hyperplasia is a metaplastic process with a pyloric gland phenotype Aims: Lobular endocervical glandular hyperplasia of the uterine cervix is a rare pseudoneoplastic lesion of the uterine cervix, described recently. Our aim was to characterize the clinicopathological and immunohistochemical features of lobular endocervical glandular hyperplasia, to elucidate its pyloric gland phenotype, and to distinguish it from adenoma malignum of the uterine cervix. Methods and results: Nine cases of lobular endocervical glandular hyperplasia were studied histologically and immunohistochemically. The average age of the nine patients was 48.8 years (range 38–64 years). Six cases were found incidentally, whereas in three cases a watery vaginal discharge and imaging studies suggested adenoma malignum preoperatively. Microscopically, lobular endocervical glandular hyperplasia ranged from 1 mm to 20 mm (mean 6.8 mm) in the largest horizontal extent and 1 mm to 10 mm (mean 3.9 mm) in depth, and was characterized by lobular arrangements of small glands composed of low columnar cells with pale eosinophilic cytoplasm and bland nuclei. Three cases showed a pseudo-invasive growth. Intracytoplasmic mucin was predominantly PAS-positive, and seven cases showed immunoreactivity for M-GGMC-1, an antibody that reacts with pyloric gland-type mucin. Only focal and faint reactivity for CEA was seen, and ER was negative in all cases. The cytokeratin profile was CK7+/20– in all cases, in keeping with their Müllerian derivation. All three lesions examined contained chromogranin-positive endocrine cells. After surgery all patients are well without recurrent disease (mean follow-up was 48.4 months). Conclusions: Lobular endocervical glandular hyperplasia is a morphologically distinct pseudoneoplastic glandular lesion, which has unique phenotypic characteristics shared by pyloric glands of the stomach. Although most are found incidentally, some cases may show clinical and radiological features resembling those of adenoma malignum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2559.2001.01239.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Effect of rebamipide on prostaglandin receptors-mediated increase of inflammatory cytokine production by macrophages (2003)
    Oxford, UK : Blackwell Publishing Ltd
    Alimentary pharmacology & therapeutics 18 (2003), S. 0 
    Details
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background : Rebamipide (Reb) is an anti-ulcer drug, and has unique properties such as anti-inflammatory action. We previously reported that prostaglandins (PGs) dramatically increased vascular endothelial growth factor (VEGF), a known angiogenic factor and a vascular permeable factor, by activated macrophages through specific PGE receptor and peroxisome proliferator-activated receptor γ (PPARγ, a nuclear receptor of PG) mediated process. Effects of PGs on the production of other cytokines such as interleukin (IL)-6 and IL-8 have been controversial.Aim : To clarify the anti-inflammatory roles of Reb, we examined the effect of Reb on PGE1- and 15-deoxy-Δ12, 14-PGJ2 (a potent PPARγ ligand, 15d-PGJ2) -induced increase of VEGF production by macrophages. Additionally, effects of these PGs on the production of IL-6 and IL-8, and modulation of these actions by Reb were studied.Methods : Phorbol 12-myristate 13-acetate-differentiated U937 cells were used as a human macrophage model (H-Mac). VEGF, IL-6, IL-8 and cAMP were measured by EIA.Results : Reb suppressed PGE1-, but not 15d-PGJ2-, induced increase of VEGF production partially through decrease of cAMP formation. Reb suppressed PGE1 -, but not 15d-PGJ2-, induced increase of IL-6 and IL-8 production.Conclusion : Reb suppresses membrane, but not nuclear PG receptors mediated increase of inflammatory cytokine production, which may be involved in anti-ulcer action of this drug.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2036.18.s1.13.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...