Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1985-1989  (14)
  • 1975-1979  (8)
  • 1930-1934  (1)
  • 1925-1929  (3)
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 1488-1491 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 675-677 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 226-228 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 2646-2648 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 1717-1719 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 113 (1985), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: P-1894B an inhibitor of collagen prolyl hydroxylase was applied topically to cotton pellet-induced granuloma and to skin lesions in rats. The total hydroxyproline content of the granulomata was significantly reduced by this agent. It also reduced the hydroxyproline content in the tissues surrounding skin lesions during the healing process, with delayed diminution in lesion size. These results suggest that collagen prolyl hydroxylase inhibitor P-1894B may be a suitable agent for topical treatment of hypertrophic scar tissue or keloid.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-1920
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Delayed enhanced CT was performed in 53 cases and these findings are compared with those of delayed radioisotope scan and with operative and histopathologic findings. We have classified the results of enhancement into four types as follows: (1) immediate enhancement pattern due to rich vascular bed, typical in meningiomas; (2) delayed enhancement pattern due to exudation, often seen in cystic astrocytomas; (3) intermediate sustained pattern due to both mechanisms in glioblastoma multiforme; (4) no enhancement pattern as in diffuse astrocytomas. The results of delayed enhanced CT correlated well with those of radioisotope scan.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 11 (1976), S. 151-157 
    ISSN: 1432-1920
    Keywords: Cerebral venous drainage ; Quadrigeminal veins ; Tectum mesencephali ; Quadrigeminal plate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The normal course and appearance of the veins draining the tectum mesencephali proper are described in detail on the basis of the anatomical radiological study. These specific veins, the quadrigeminal veins, were constantly present on autopsy study. There are two types of variations of these quadrigeminal veins. They have a close anatomical and angiographic correlation with the quadrigeminal plate proper, and also outline the posterior aspects of the quadrigeminal plate. The whole structure of the mesencephalon may be delineated by these veins in combination with the other veins of the mesencephalon. They may be of diagnostic value in the early recognition of the brain stem lesions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 2 (1988), S. 124-128 
    ISSN: 1432-198X
    Keywords: Epidermal growth factor ; Mouse ; Kidney ; Submaxillary gland ; Ontogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The developmental changes in epidermal growth factor (EGF) have been studied in tissue homogenates, kidney slices, and microdissected nephron segments of the mouse. Immunoreactive EGF concentration per milligram of protein increased in the kidney by about 20-fold from 1 week to 3 weeks of life, reaching the highest levels between 5 and 7 weeks, and decreasing by 10 weeks of life. The time course of the changes was different from those of submaxillary and urinary EGF. Above 7 weeks of age, kidney EGF was higher in female than in male mice. Among various zones of the kidney (outer cortex, inner cortex, outer medulla I, II and papilla), the outer medulla I and II contained the highest quantities of EGF per gram of wet tissue. The highest EGF content per millimeter length was observed in the medullary and cortical thick ascending limbs of Henle's loop. The amounts exceeded by about 4.5-fold those found in glomeruli and in proximal convoluted and proximal straight tubules, and by about 3-fold those present in distal and collecting tubules. Unilateral nephrectomy resulted in no significant changes in EGF levels in the contralateral kidney. The results suggest that the ontogeny of kidney EGF is different from that of the EGF found in the submaxillary gland, and that there is nephron heterogeneity in EGF content.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-1920
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Metrizamide CT cisternography (CTC) was performed for the evaluation of CSF dynamics and the diagnosis of skull-base tumors. Results of CTC in 52 cases examined for the study of CSF dynamics correlated well with those of isotope cisternography. However, the degree and duration of ventricular stasis of metrizamide and its transition into a periventricular low-density area in hydrocephalus were recognized more accurately in CTC. Twenty out of 23 cases with suspected skull-base tumor were diagnosed as positive and confirmed by operation. CTC was especially useful in parasellar, CP angle, and other posterior fossa tumors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...