Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Photoluminescence and photoluminescence excitation studies on GaAs/Al0.25Ga0.75As asymmetric coupled double quantum well (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 3475-3478 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Photoluminescence (PL) and PL excitation (PLE) experiments on a GaAs/Al0.25Ga0.75As asymmetric coupled double quantum well are reported. In PLE, the seven peaks, four related to the heavy-hole coupled and the rest to the light-hole coupled excitonic states, are observed. The positions of seven peaks observed in PLE are in good agreement with the calculated results of multi-band envelope function approximation using the transfer matrix method. The result of the temperature-dependent PL above 100 K shows that, even though the wavefunctions are localized in different wells separated by 8 monolayer barrier, the heavy-hole coupled excitons in the two lowest levels are in thermal equilibrium. The observed activation energy is equal to the difference between the two levels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354524
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Study of surface-emitted stimulated emission in GaN (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 729-731 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of a study of spatially resolved surface-emitted stimulated emission in GaN epilayer samples under conditions of strong optical pumping. We observe that even at excitation powers near the damage threshold, no surface-emitted stimulated emission occurs from samples with a high quality GaN epilayer. In parts of the samples with inferior surface quality, we show that stimulated emission comes from cracks, burned spots, and other imperfections, and is due to the scattering of a photon flux propagating parallel to the surface. Our results suggest that these defects are effective scattering centers and can severely affect the accuracy of optical gain measurements. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.119627
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Time-resolved study of yellow and blue luminescence in Si- and Mg-doped GaN (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 840-842 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Time-resolved photoluminescence has been employed to study the donor-acceptor pair recombination kinetics of the yellow (∼2.3 eV) and blue (∼2.8 eV) luminescence bands in Si- and Mg-doped GaN layers, respectively. As the Si doping concentration in Si-doped GaN increases, the lifetime τ1/e of the yellow luminescence decreases, indicating that a shallow Si donor is the origin of the yellow luminescence. The blue luminescence is most likely due to a shallow Mg acceptor and a deep donor composed of a Mg acceptor-nitrogen vacancy complex, as seen by the independence of τ1/e on the Mg concentration measured by secondary ion mass spectroscopy in the range (2.5–6.0)×1019 cm−3. As the temperature is increased from 10 to 300 K, the lifetimes for the yellow and blue luminescence remain nearly constant, indicating that the distribution of electrons and holes bound to donors and acceptors does not change much with increasing temperature. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.125602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    High resolution x-ray analysis of pseudomorphic InGaN/GaN multiple quantum wells: Influence of Si doping concentration (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 3006-3008 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the structural properties of InGaN/GaN/AlGaN multiple quantum wells (MQWs) by means of two-dimensional reciprocal space mapping (RSM) of high resolution x-ray diffraction. The influence of Si doping in GaN barriers on the characteristics has been studied for 12-period MQWs grown by metalorganic chemical vapor deposition, which have different Si doping concentrations in the GaN barriers ranging from 1×1017 to 3×1019 cm−3. Information on the structural quality of these MQWs was extracted from the linewidth broadening of the higher-order superlattice satellite peaks, as well as from the presence of Pendellösung oscillations. The measured diffraction curves were modeled using kinematic diffraction theory. From the symmetric and asymmetric RSMs around (0002), (0004) and (112¯4) reflections, we found that the InGaN/GaN/AlGaN MQWs are grown coherently on the GaN base layer. Better interface properties are achieved with Si doping. Our results indicate that Si doping in the GaN barriers affects the interface quality of the InGaN/GaN MQW systems, and thus, also influences the optical properties. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369620
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Myelin basic protein inhibits histone-specific protein methylase I
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular 874 (1986), S. 30-36 
    Details
    ISSN: 0167-4838
    Keywords: (Brain) ; Enzyme inhibitor ; Histone-specific protein methylase I ; Myelin basic protein ; Protein-arginine-methyltransferase
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0167-4838(86)90098-1
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Inhibitory effect of arginine-derivatives from ginseng extract and basic amino acids on protein-arginine N-methyltransferase (1999)
    Springer
    Amino acids 17 (1999), S. 391-400 
    Details
    ISSN: 1438-2199
    Keywords: Amino acids ; Protein ; arginine methyltransferase ; Inhibitors ; Ginseng extract ; Arginine derivatives ; Basic amino acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Protein-arginine N-methyltransferase (protein methylase I) catalyzes methylation of arginyl residues on substrate protein posttranslationally utilizing S-adenosyl-L-methionine as the methyl donor and yields NG-methylarginine residues. Arginyl-fructose and arginyl-fructosyl-glucose from Korean red ginseng were found to inhibit protein methylase I activity in vitro. This inhibitory activity was shown to be due to arginyl moiety in the molecules, rather than that of carbohydrates. Several basic amino acids as well as polyamines were also found to inhibit protein methylase I activity. Interestingly, the intensity of the inhibitory activity was correlated with the number of amino-group in polyamines, thus, in the order of spermine 〉 spermidine 〉 putrescine 〉 agmatine-sulfate, with IC50 at approximately 15 mM, 25 mM, 35 mM, and 50 mM, respectively. On the other hand, neutral amino acids or NaCI did not inhibit the enzyme activity. Lineweaver-Burk plot analysis of the protein methylase I activity in the presence of arginine and spermidine indicated that the inhibition was competitive in nature in respect to protein substrate, with the Ki values of 24.8 mM and 11.5 mM, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01361664
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Recent advances in protein methylation: Enzymatic methylation of nucleic acid binding proteins (1998)
    Springer
    Amino acids 15 (1998), S. 291-306 
    Details
    ISSN: 1438-2199
    Keywords: Protein-arginine methylation ; Nucleic acid binding protein ; Protein methylase I ; S-adenosyl-L-methionine ; RGG motiff
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Heterogeneous nuclear RNP protein A1, one of the major proteins in hnRNP particle (precursor for mRNA), is known to be post-translationally arginine-methylatedin vivo on residues 193, 205, 217 and 224 within the RGG box, the motif postulated to be an RNA binding domain. Possible effect of NG-arginine methyl-modification in the interaction of protein A1 to nucleic acid was investigated. The recombinant hnRNP protein A1 wasin vitro methylated by the purified nuclear protein/histone-specific protein methylase I (S-adenosylmethionine:protein-arginine N-methyltransferase) stoichiometrically and the relative binding affinity of the methylated and the unmethylated protein A1 to nucleic acid was compared: Differences in their binding properties to ssDNA-cellulose, pI values and trypsin sensitivities in the presence and absence of MS2-RNA all indicate that the binding property of hnRNP protein A1 to single-stranded nucleic acid has been significantly reduced subsequent to the methylation. These results suggest that posttranslational methyl group insertion to the arginine residue reduces protein-RNA interaction, perhaps due to interference of H-bonding between guanidino nitrogen arginine and phosphate RNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320895
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...