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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 59 (1986), S. 1334-1340 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The temperature distribution and evolution of metal field-ion emitters under pulsed and continuous-wave (cw) laser irradiation are obtained numerically using implicit alternating direction method. For the cw laser irradiation, the temperature distribution in the emitter reaches a steady-state value after approximately 2 μs of laser heating. The peak temperature of the tip apex reached depends almost linearly on the incident energy flux of the laser beam, and also on the cone angle of the emitter. For the fast laser pulse, both the waveform and the spatial intensity variation of the laser beam are considered. The numerical result is found to differ only slightly from that obtained by assuming a square shape of the laser pulse. The feasibility and advantages of using a laser beam as a means of heating the emitter in the study of single atom surface diffusion and adatom-adatom interaction, laser-induced silicide interface formation, and other studies with the Atom Probes and Field Ion Microscope are also discussed.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1436-5065
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geographie , Physik
    Notizen: Summary  A three-dimensional, nonhydrostatic numerical model with high spatial resolution, in which a simple energy closure scheme is employed, has been developed to simulate the spray dispersion over complex terrain. The evaporation, condensation, and dispersion of the spray and moisture are taken into account in model equations. The term of latent heat due to phase transformation is considered in detail to account for its effects on the temperature field and airflow. As an application of the model, the spray concentration and air relative humidity are calculated under neutral condition. The results indicate that under the neutral condition, the spray is transported to about 0.6 km downwind from the source, and its effects on the air humidity reach a further distance of 0.9 km downwind from the source. Attention is given to the dependence of the results upon the various factors influencing the simulation, such as the intensity of the source, the atmospheric stratification, and the dynamic factor of the terrain. Some numerical tests were carried out to provide extra insight to the effects of these factors. It has been demonstrated that the simulation results such as relative humidity and temperature are sensitive to these factors, especially to the thermal stratification. Under unstable conditions, the effects of the spray source increase significantly, and the variation extent of the temperature, relative humidity and flow field is larger than that under neutral condition. The effects of dynamic and thermal factors on the air flow field are discussed through the comparison of the modeling results over complex terrain and flat terrain.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Publikationsdatum: 2021-02-26
    Sprache: Englisch
    Materialart: article , doc-type:article
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of organic chemistry 40 (1975), S. 2252-2253 
    ISSN: 1520-6904
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3062-3067 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Analytical results are derived for the intersubband absorption quantum efficiency, which take into account contributions from both bound-to-bound state and bound-to-continuum state transitions. Including the final state lifetime broadening, the absorption spectrum gradually decreases in peak strength and becomes broader from the pure bound-to-bound case to the pure bound-to-continuum situation. The physical reason for the divergence in absorption strength when the upper state is in resonance with the top of the barrier and in the absence of broadening is discussed. The detector current responsivity as a function of well width (and hence upper state position) is estimated. Calculated examples are given, covering the crossover region from the bound-to-bound case to the bound-to-continuum case. Our results compare well with experiments.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 2029-2031 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Modeling the dark current in quantum well infrared photodetectors has been a topic of much recent research, but the implications of many of the underlying assumptions have not been clarified. We attempt to justify one such model and to provide physical insight for its success. We compare the dark current expression with experiments on several samples, and show that the model provides a good approximation for a wide range of device parameters including barrier thicknesses from 250 to 700 A(ring) and number of wells from 4 to 32.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 3458-3463 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The occurrence of stress in thin films has led to serious considerations of stability problems in the semiconductor industry. It may cause mechanical failure of films, such as adhesion reduction or contact peel-off, or variations in electrical properties. The existence of stress will also alter electromigration behavior for thin metal lines. The elastic stress in a multilayered structure due to thermal processing is calculated by use of the principle of mechanics balance. It is found that the variation of thickness in one film will not affect the magnitude of stress in another film. The shearing and peeling stress at the edge of a patterned structure, which is responsible for the peeling of a film at the edge, is then modeled and discussed in detail. Finally, the relaxation of stress by viscous motion of SiO2 is analyzed based on Maxwell's viscoelastic model.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 2611-2614 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Under high-dosage boron implant, the implant condition was found to be important for reducing the transient-enhanced diffusion of boron in Si and forming shallow p+n junction with good rectifying characteristics as well as high dopant concentration in the diffused region. The BF2+-implantation resulted in not only an excellent dopant activation but also a reduced anomalous diffusion due to the formation of amorphous layer and the scarce defects underneath the amorphous/crystalline (a/c) interface. The B+-implanted crystalline samples manifested a poor activation efficiency, and a largely anomalous diffusion at the high temperature with prolonged-time annealing ascribed to much damage induced by the high-dose implant. The B+-implanted pre-Si+-amorphized samples also displayed severely transient-enhanced diffusion in spite of the good dopant activation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 2039-2041 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report on an experimental long wavelength infrared photocurrent study of a series of a Si-SiGe double-heterostructure samples. The active region is a thin heavily p-type doped SiGe layer, and the photoexcited holes due to free-carrier absorption are collected over the potential barrier resulting from the Si-SiGe valence-band offset. Photocurrent spectra with different cutoff wavelengths are observed for samples with different SiGe compositions, arising from internal photoemission in the Si-SiGe heterojunction. Photocurrents at finite biases and at zero bias (i.e., photovoltaic operation) are studied. Optimizing device parameters may lead to detector structures for large focal plane arrays.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 7560-7563 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report the results of an experimental study of intersubband transitions in a coupled asymmetrical double quantum well structure. Infrared transmission and photocurrent spectra are measured at 80 K. One period of the 40-repeat quantum well structure consists of a wide Si-doped GaAs well and a narrow undoped GaAs well separated by a thin AlGaAs barrier. The intersubband transition in the wide well occurs at about 9.5 μm, and, under appropriate bias, an intersubband absorption feature in the narrow well appears at 6.2 μm. The switching between intersubband transitions at 9.5 and 6.2 μm relies on electron transfer between the wells. Our absorption measurements provide direct evidence that up to 35% of the 9.2×1011 cm−2 electrons in the wide well can be transferred into the narrow well. These transferred electrons give rise to a photocurrent peaked at 6.2 μm.
    Materialart: Digitale Medien
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