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
    Propagation model for the dynamics of gain-guided semiconductor laser arrays (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 462-464 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A model is presented for the spatiotemporal dynamics of gain-guided semiconductor laser arrays. The model goes beyond coupled mode theory and treats the array as a single entity. Numerical simulations of twin-stripe gain-guided arrays yield stable or pulsing outputs, depending on array parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353873
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The Relationship Between N2 and N400: Scalp Distribution, Stimulus Probability, and Task Relevance (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 28 (1991), S. 0 
    Details
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: The N2 and N400 components of the event-related brain potential were compared along several dimensions. In one task, subjects discriminated on the basis of size, and in another task, subjects discriminated on the basis of semantic category. In one set of conditions stimuli deviated infrequently along one stimulus dimension (either in size or semantic category) and in another set of conditions stimuli deviated infrequently along two stimulus dimensions (both size and semantic category). When subjects discriminated on the basis of size, infrequent deviation in the size of the stimuli was associated with a negativity that peaked around 320 ms (N2). When subjects discriminated on the basis of semantic category, infrequent deviation in the semantic category of the stimuli was associated with a negativity that peaked around 400 ms (N400). N2 and N400 were found to be generally alike in scalp distribution, hemispheric asymmetry, and sensitivity to stimulus probability. N2 was not elicited when size changes were task irrelevant and N400 was not elicited when changes in semantic category were task irrelevant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1469-8986.1991.tb00411.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    FOREIGN MANPOWER IN THE U.S. SCIENCES (1968)
    Oxford, UK : Blackwell Publishing Ltd
    Review of income and wealth 14 (1968), S. 0 
    Details
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: Because of the recent public concern over the brain drain, this study attempts to measure the U.S. gain of highly skilled manpower. The paper discusses the serious short-comings of the data on gross immigration of scientists and engineers provided by the U.S. immigration authorities as a measure of true U.S. gains. In a case study of Swedish scientists and engineers it was found, for example, that whereas the U.S. data showed a gain of 106 Swedish scientists and engineers over a number of years, the net figure was only 26 after adjustment for remigration and the application of the proper OECD education criteria.The paper then reports the findings of a statistical study which uses the stock data on U.S. scientists in the National Register of Scientific and Technical Personnel to estimate the number of foreign born in this stock and analyse their characteristics with respect to age, educational attainment, and employment preferences.It was found that nearly 7 percent of all U.S. scientists are of foreign origin (foreign born and foreign secondary education), whereas 11.5 percent of all scientists with a Ph.D. are of foreign origin. The percentage among Ph.D. holders is highest in meteorology (22.3), followed by linguistics (18.7), physics (17.1) and statistics (14.6).The greatest percentage of scientists comes from Canada (10.4 per thousand), followed by Germany (8.3 per thousand) and the United Kingdom (6.7 per thousand). However, after adjustment of these data for the different sizes of the total foreign born population from each country in the U.S., it turns out that by this measure the greatest shares of scientists are supplied by the Japanese, followed by the Austrian-Swiss, Benelux and Canadians.The analysis of the age composition of all foreign born reveals that in the age groups that were 20–29, 45–54, and 65 and over in 1964 foreigners represent a smaller than average share, probably reflecting war casualties and education completed at a later age. Germans and Austrians are heavily concentrated in the group 55–64 years old in 1964, suggesting that a great share of scientists from these countries may have been victims of a brain push.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1475-4991.1968.tb00936.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Exchange reactions of carboxylic acid salts. Facile preparation of .alpha.-deuteriocarboxylic acids (1968)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 90 (1968), S. 498-499 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01004a054
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Modulational instability in nonlinear periodic structures: Implications for "gap solitons'' (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 1001-1003 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A nonlinear periodic structure can convert an input continuous wave beam into a train of pulses. This modulational instability implies that the nonlinear spatial resonance ("gap solitons'') of distributed feedback structures are generally unstable. Stability is assured only for low coupling strengths or large detunings from the Bragg condition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.104404
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Mismatch Detection and the Latency of Temporal Judgments (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 29 (1992), S. 0 
    Details
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Event-related potentials were recorded in two auditory tasks involving the discrimination of pitch or duration of binaurally presented tones. Frequently-presented nontarget tones, when compared to the same tones in a simple reaction time task, elicited two negative peaks, NA1 and NA2, followed by a positive peak, nontarget positivity. Infrequently-presented target tones, when compared to the nontargets, elicited mismatch negativity (MMN), followed by N2 and P3b. The peak latencies of NA1 and NA2 did not differ between the pitch and duration tasks, but the duration of NA1 and the peak latencies of mismatch negativity, N2, and P3b, as well as reaction time, increased in parallel for the duration task. It is proposed that the NA1-nontarget positivity sequence reflects the initiation, maintenance, and termination of an attention-modulated process, which is required for the performance of an auditory discrimination task, and that the MMN-N2-P3b sequence reflects a process elicited by infrequently-presented targets, which is the main determinant of reaction time under these testing conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1469-8986.1992.tb01713.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The Chronometry of Attention-Modulated Processing and Automatic Mismatch Detection (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Psychophysiology 29 (1992), S. 0 
    Details
    ISSN: 1469-8986
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: Event-related potentials were recorded from normal subjects in an auditory selective attention task. Targets were rare longer (170-ms) tones of a designated pitch, embedded in a sequence of 100-ms standard tones. The effects of attention-modulated processing were evident in the event-related potentials elicited by the standards. Those to relevant standards were similar for easy (1000 Hz vs. 2000 Hz) and hard (1000 Hz vs. 1030 Hz) pitch separations, and were more negative frontocentrally than those to irrelevant standards. Difference waveforms (attended minus unattended standards) revealed Nd, a negative deflection that was earlier in latency for the easy task (onset, 120 ms; peak, 250 ms) than for the hard task (onset, 250 ms; peak, 350 ms). The speed of detection of the deviant longer tones was insensitive to the attention-modulated processes indexed by Nd. Median reaction time did not differ between tasks, although there were more misses and false alarms in the hard task (and nearly all of the latter were to the irrelevant longer tones). Neither direction of attention nor task difficulty affected the latency of mismatch negativity, N2, or P3 (as identified in difference waveforms: attended or unattended longer tones). minus their respective standards). The data suggest that performance was guided by two independent but converging processes, automatic mismatch detection of the longer tone and attention-modulated processing of pitch, followed by selection of response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1469-8986.1992.tb01714.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Dynamics of resonant optical waveguide semiconductor laser arrays (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 3226-3228 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A propagation model is presented for the dynamics of antiguided semiconductor laser arrays. The model takes into account diffraction, carrier diffusion, spatial hole burning, and carrier-induced antiguiding. Numerical results reveal a variety of spatiotemporal behaviors ranging from stable, quiescent operation to periodic and erratic intensity oscillations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.109081
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Temporal behavior of resonant-optical-waveguide phase-locked diode laser arrays (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 64 (1994), S. 827-829 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Measurements of the temporal and spatial behavior of resonant optical waveguide (ROW) laser arrays with significant interelement loss reveal the presence of sustained self-pulsations in the output intensity of the laser. The mechanism responsible for pulsations is believed to be saturable absorption arising from the presence of absorbers in the interelement regions. This is experimentally confirmed in that reduction or elimination of the interelement loss suppresses the pulsations. Quiescent behavior is obtained to at least 0.45 W continuous wave power and 3.4 times threshold in near-diffraction-limited beams from devices with negligible interelement loss.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.111027
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Agricultural Uses of Coal and Its Products (1943)
    s.l. : American Chemical Society
    Industrial & engineering chemistry 35 (1943), S. 139-144 
    Details
    ISSN: 1520-5045
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ie50398a004
    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...