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
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 3745-3749 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report characterization of Si p-n junction arrays using simultaneous conductance imaging and constant current mode (topographical) scanning tunneling microscopy imaging over a range of reverse bias conditions. Both constant current and conductance imaging of the electrically different regions (n, p, and inverted region) show a pronounced dependence on applied p-n junction bias. Tunneling spectra measured across the p-n junction show that the conductance contrast agrees well with the expected variation due to tip-induced band bending. Taken in combination with the topographical image, conductance images can be used to characterize spatial variations of carrier densities across the device. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 1477-1481 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Voltage-modulated scanning force microscopy (Piezoresponse microscopy) is applied to investigate the domain structure in epitaxial PbZr0.2Ti0.8O3 ferroelectric thin films grown on (001) SrTiO3. By monitoring the vertical and lateral differential signals from the photodetector of the atomic force microscope it is possible to separate out and observe the out-of-plane and in-plane polarization vectors in the thin film individually. The relative orientation of the polarization vectors across a 90° domain wall is observed. Nucleation of new reversed 180° domains at the 90° domain wall is studied and its impact on the rotation of polarization within the a domain is analyzed as a function of reversal time. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 469-475 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present a model that describes doping-induced contrast in photoelectron emission microscopy by including the effect of surface state distributions and doping-induced band gap reduction. To quantify the contrast, the photoyield from the valence band for near-threshold photoemission is calculated as a function of p-type doping concentration in Si(001). Various surface state distributions appropriate for a native-oxide covered Si device are investigated in order to determine the effect on doping-induced contrast. The lower limit on the number of surface states necessary for doping-induced contrast to occur is approximately 5×1013 cm−3. An interesting result is that neither the position nor the energy distribution of the surface donor states affects the contrast, which corresponds to approximately a factor of 2 change in intensity for each decade change in doping density. However, the overall intensity increases with any one of: increased surface state density, narrowing of surface state distribution, or increased energy of surface states with respect to the valence band. The band bending profile generated by the model predicts that doping-induced contrast will be affected by varying the incident photon energy. Experimentally, we verify this prediction by imaging with photon energies between 4.5 and 5.2 eV. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 92 (2002), S. 1256-1261 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The utility of vertical propagation by the Green's function to test response linearity has been explored for magnetic force microscopy (MFM) data from current-carrying wires, by comparing the measured signal at various tip heights to the corresponding propagated MFM signals. Application of a one-dimensional Green's function was found to be sufficient to predict signal height variation for sample regions of high to moderate field symmetry. For regions of high field asymmetry, the two-dimensional Green's function was required to obtain good prediction of the height variation. Agreement between the measured and propagated signals was generally within 5%, except at the tails where the signal is not well behaved. The quality of agreement deteriorates gradually with the size of the height propagation. The good agreement spanning a decade of tip and sample separation suggests that the MFM signal is not significantly affected by nonlinearities and can thus be interpreted in terms of classical electromagnetic relations governing current flow. © 2002 American Institute of Physics.
    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 77 (2000), S. 3275-3277 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The time-dependent relaxation of the remanent polarization in epitaxial lead zirconate titanate (PbZr0.2Ti0.8O3) ferroelectric thin films, containing a uniform two-dimensional grid of 90° domains (c axis in the plane of the film), is examined using piezoresponse microscopy. The 90° domain walls preferentially nucleate the 180° reverse domains during relaxation, with a significant directional anisotropy. Relaxation occurs through the nucleation and growth of reverse domains, which subsequently coalesce and consume the entire region as a function of time. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 3547-3549 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We investigate the variation in doping-induced contrast with photon energy in photoelectron emission microscopy images of Si pn devices using a free-electron laser as a tunable monochromatic light source. Photoyield is observed from p-doped regions of the devices for photon energies as low as 4.5 eV. Band tailing is the dominant effect contributing to the low energy photoyield from the heavily doped p regions. The low intensity tail from the n regions, however, may be from surface states. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 2661-2663 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The spatial variation of current density in lines with model void defects fabricated using focused-ion beam milling has been imaged using magnetic force microscopy (MFM). At current densities of 3–4×106 A/cm2, an asymmetry in the MFM signal is clearly visible at (1×1) μm2 and (0.5×0.5) μm2 notches at the edge of a 10 μm wide line. Comparison to a simple model calculation suggests that the asymmetry is due to current crowding, with the displaced current 70% localized to within 1μm of the notch. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Histopathology 15 (1989), S. 0 
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We have studied three examples of benign thyroid tumours which conform to the lesion recently described as hyalinizing trabecular adenoma. The prominent feature of this trabecular epithelial lesion is the extracellular deposition of an eosinophilic material that does not show the features of amyloid; the epithelial cells may be elongated, sometimes radially arranged around the eosinophilic material. All three tumours showed positive immunocytochemical staining for thyroglobulin, keratin, chromogranin and neuron-specific enolase. One tumour showed isolated cells with immunoreactivity for somatostatin, argyrophil cytoplasmic granularity with the Grimelius technique, and ultrastructurally demonstrable cytoplasmic electron-dense endocrine granules. The hyaline extracellular material in all three tumours showed strong immunoreactivity for both type IV collagen and laminin. Previous radiation may be important in the causation of this tumour, and it shows a frequent association with severe thyroiditis. We conclude that the main histological feature of this lesion, the hyaline material, is due to the overproduction of a basement membrane-like material by the neoplastic follicular cells. The presence in one tumour of evidence of endocrine differentiation may reflect the potential for follicular cells to show biphasic differentiation, a feature which may be more frequent than has been previously recognized. Several of the other features of this tumour–-for example the frequent intranuclear cytoplasmic inclusions–-may lead to diagnostic problems, and the entity deserves wider recognition.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Weed research 13 (1973), S. 0 
    ISSN: 1365-3180
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary. To assess the role of seed production and seedling behaviour in the biology of the perennial grass weed Agrostis gigantea Roth, seed germination and seedling emergence of the species were investigated in the glasshouse and in the laboratory. These studies showed that the species may produce a large number of seeds: panicles collected from a cereal field in 1971 and 1972 contained about a thousand viable seeds in both years. Mature seeds of the species are mostly non-dormant and germinate readily on moist soil surfaces. Freshly-harvested seeds require light and alternating tempratures for germination, but older seeds can germinate in constant temparature in the dark. Covering seeds with 0·6 cm soil halved the percentage emergence and few seedlings emerged from seeds sown deeper than 3±8 cm, but many seeds survived under enforced dormancy. A. gigantea seeds may also persist long in frequently cultivated shallow soil. The species flowers late but its seeds become viable quickly—in 1969 a third of the number that were finally viable became so within a week of flowering. Germination des semenes d' Agrostis gigantean Roth.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Weed research 13 (1973), S. 0 
    ISSN: 1365-3180
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary. Seedlings and plants derived from single-node rhizome fragments of Agropyron repens and Agrostis gigantea were grown in au unheated glasshouse, separately or together with wheat (cv. Kolibri), in sandy loam soil in well-spaced pots, adequately watered and moderately fertilized. Samples of crop and weeds were taken for growth analysis in mid- May, late June and early August (when the wheat was ripe).On average, wheat decreased the weight of weed shoots by 84% and of rhizomes by 77%, but the weeds decreased the weight of wheat shoots by only 7% and of grain by 13%. Without wheat, seedlings of both weed species had, by late June, grown as much as plants from rhizomes, but with wheat, the weed seedlings were throughout most of the experiment more susceptible to competition than were plants from rhizomes. There was no simple relationship between the final dry weights of the weeds and the amount they decreased wheat yield: although Agropyron seedlings in competition with wheat were much lighter than Agrostis from rhizomes, they decreased grain yield of wheat as much, suggesting that they competed more intensely for a limiting factor, possibly nitrogen.It is concluded that the faster initial growth rate of wheat seedlings relative to the weeds from rhizomes and a larger initial seed reserve relative to the weed seedlings enabled the wheat to dominate the weeds. Comparaison de la croissance et comportement compétitif de plantules et de plantes issues de rhizomes d'Agropyron repens (L.) Beauv. et d' Agrostis gigantea Roth
    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...