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
Filter
  • 1995-1999  (7)
  • 1
    Electronic Resource
    Electronic Resource
    Tunneling and relaxation of photogenerated carriers in near-surface quantum wells (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 5712-5717 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It is shown that photoluminescence emission from AlGaAs/GaAs and InGaAs/GaAs near-surface quantum wells can be a nonlinear function of the excitation-power density depending on the surface-barrier thickness and on the conditions of the barrier-oxide interface. By studying the rate-equation system, it is shown that this nonlinear effect is mainly due to the competition between tunneling to surface states and relaxation of photogenerated carriers within the quantum well. The information about surface states that one can obtain from this nonlinear behavior is also discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359214
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Survey of reference materials for trace elements, nuclides and organic microcontaminants (1998)
    Springer
    Fresenius' journal of analytical chemistry 360 (1998), S. 350-353 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The International Atomic Energy Agency (IAEA), in co-operation with the United Nations Environment Programme (UNEP), has recently prepared a survey on internationally available analytical reference materials for trace elements, nuclides and organic contaminants in biological, environmental and related matrices. The purpose is to help analysts to select reference materials for quality assurance that match as closely as possible, with respect to matrix type and concentrations of the measurands of interest, the “real” samples that are to be measured. The present version of the survey, which is available in the form of two cost-free printed volumes [1], contains over 10,000 certified and information values in 650 reference materials from 27 different producers. The 455 measurands listed include trace elements, major and minor elements, organic contaminants, organometallic compounds, radionuclides and stable isotopes. Currently, the database from which the survey has been produced is being modified and extended so as to make the data available in electronic form via the Internet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050708
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Parallel implementation of large-scale structural optimization (1998)
    Springer
    Structural and multidisciplinary optimization 16 (1998), S. 176-185 
    Details
    ISSN: 1615-1488
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Advances in computer technology and performance allow researchers to pose useful optimization problems that were previously too large for consideration. For example, NASA Langley Research Center is investigating the large structural optimization problems that arise in aircraft design. The total number of design variables and constraints for these nonlinear optimization problems is now an order of magnitude larger than anything previously reported. To find solutions in a reasonable amount of time, a coarse-grained parallel-processing algorithm is recommended. This paper studies the effects of problem size on sequential and parallel versions of this algorithm. For initial testing of this algorithm, a hub frame optimization problem is devised such that the size of the problem can be adjusted by adding members and load cases. Numerous convergence histories demonstrate that the algorithm performs correctly and in a robust manner. Timing profiles for a wide range of randomly generated problems highlight the changes in the subroutine timings that are caused by the increase in problem size. The potential benefits and drawbacks associated with the parallel approach are summarized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01202828
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Monitoring the efficacy of hybrid selection during positional cloning: the search for BRCA1 (1995)
    Springer
    Mammalian genome 6 (1995), S. 873-879 
    Details
    ISSN: 1432-1777
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Positional cloning often requires isolation of candidate genes from a large, genetically defined region. Hybrid selection (direct cDNA selection, solution hybrid capture) is a rapid, simple procedure that has been used to identify expressed sequence tags (ESTs) from cloned genomic DNA. We used hybrid selection to screen a 600-kb region that includes the BRCA1 gene. From a set of 931 sequenced clones, we obtained 118 nonoverlapping candidate ESTs from ovary and lymphocyte cDNA. We analyzed the results of our hybrid selection experiments with particular attention to the overall completeness, efficiency, and background noise of the experiment. We introduce simple parameters that serve as measures of important aspects of the hybrid selection process in the context of positional cloning.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00292438
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Nuclear techniques applied to air particulate matter studies (1997)
    Springer
    Journal of radioanalytical and nuclear chemistry 217 (1997), S. 5-10 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The most important fraction of aerosols with respect to human health is the respirable fraction, which has particles less than 10 μm in equivalent aerodynamic diameter (EAD), the so called PM 10 fraction. The collection of these respirable particles and the determination of their trace element composition is the focus of an IAEA Co-ordinated Research Programme (CRP). The IAEA Laboratory participated in this Programme and established collection sites for the air particulate samples on the grounds of the Atominstitute of the Austrian Universities in Vienna and the IAEA Laboratories, Seibersdorf, representing an urban residential site and a rural site. The collected samples as well as samples of simulated air filters (used also for blind controls) and control materials were analyzed sequentially and/or in sections by X-ray fluorescence (XRF), proton induced X-ray emission (PIXE), instrumental neutron activation analysis (INAA), and atomic absorption spectrometry (AAS). Results demonstrate the applicability of the PM-10 sampling approach, provided PIXE and/or INAA are used in the determinations. Reliable results can be obtained that will lead in comparable air pollution data for many regions in the world through CRP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02055341
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Elemental characterization of a candidate lichen research material — IAEA-336 (1995)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 352 (1995), S. 227-231 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A lichen research material, prepared from the species Evernia prunastri, was produced by a co-operation between the International Atomic Energy Agency (IAEA) and the Instituto de Ciencias e Engenharia Nucleares (INETI) in Sacavém, Portugal. An international intercomparison study was carried out, with 42 independent sets of results being reported from participants in 26 countries. The statistical evaluation of the collected data resulted in recommended values for 17 elements and information values for 15 elements. The criteria for assigning the values are provided, including the use of information obtained through the parallel analysis of a second material, IAEA-359, Cabbage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00322332
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Production of hair intercomparison materials for use in population monitoring programmes for mercury and methylmercury exposure (1995)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 352 (1995), S. 184-187 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Ten kilograms of hair obtained from India were used as the basis for two intercomparison materials, one with natural low levels of mercury and methylmercury, and one with an elevated level of methylmercury. The latter was produced by labeling the hair with a solution containing methylmercury. To convert the hair into homogeneous powders, cryogenic milling was utilized. 70% of the final material passed through a 0.075 mm sieve. Subsequent studies were carried out to establish the homogeneity of the materials and the stability of the methylmercury label. The materials will be distributed in an international intercomparison, the results from which will be used to obtain recommended values for total mercury and methylmercury.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00322322
    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...