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
    Transition of V6O13 to VO2 observed with a high-resolution electron microscope (1975)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 660-664 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Under irradiation by an intense electron beam a V6O13 crystal reacts with the carbon deposited on the surface during microscopic observation. The structural changes during the reaction were directly observed by means of lattice images, in which the array of VO6 octahedra was resolved. At the initial stage cavities smaller than 20 Å in diameter appear preferentially in the thin part of the crystal and some crystallographic shear planes are formed in their wall. The cavities with the heavily distorted surroundings are seen as white regions. Kinks in lattice fringes, indicating the occurrence of stacking faults, are simultaneously found in the matrix. At the advanced stage the VO2 phase and its twin component are produced. The mechanism of the transition of V6O13 to VO2 can be interpreted in terms of the cooperative movement of octahedra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0567739475001398
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Superstructures in an imperfectly quenched vanadium monosulphide VS1.155, as observed by high-resolution electron microscopy (1976)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 32 (1976), S. 558-565 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The contrast of electron microscope lattice images of a vanadium monosulphide with superstructures was dynamically calculated on the basis of the multislice method. Interactions of 80 waves were analysed. It was shown that the vacancy-rich vanadium sites were imaged as white spots not only at the very thin part but also at the thicker part inside the first equal-thickness contour, which appeared at the thickness of 60 Å. A non-stoichiometric vanadium monosulphide, VS1.155, quenched imperfectly from the preparation temperature at 1217 °C, was examined on the basis of the lattice image observation by a 100 kV high-resolution electron microscope. Orderings in the inter- as well as intralayers could be recognized directly from the arrangement of the white spots. Interpretable lattice images appeared exclusively inside the first equal-thickness contour. A mixture of some different types of images was observed in a crystal fragment; in some band-like regions the 4C-type superstructure was found with almost the same structure as Fe7S8. Each band extended parallel to the (001) plane with thickness of at most 50 Å and the orientation was in a twin relation to that of the adjoining one. The other regions showed less well-defined lattice images, although they gave the broad diffraction peaks ranging from the 4C- to 3C-type reflexions. In order to determine the phase relations at high temperatures the specimen was heated by focusing an electron beam on the portion slightly apart from the area under examination. The technique enabled us to observe only the heating effect. Upon heating, the 4C type first increased in volume, seen by the thickening of some bands. On further heating the 3C type increased in intensity on the diffraction pattern. The structure of the 3C type was estimated to be almost the same as Fe7Se8 except that the vacancy concentration fuctuated among the partially occupied vanadium layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0567739476001228
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    New electron microscopy for composition analysis of GaAs/Al"xGa"1"-"xAs heterointerfaces
    Amsterdam : Elsevier
    Surface Science Letters 174 (1986), S. A427 
    Details
    ISSN: 0167-2584
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0167-2584(86)90017-4
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Electron microscopic characterization of cubic BN prepared by water solvent
    Amsterdam : Elsevier
    Journal of Crystal Growth 43 (1978), S. 345-350 
    Details
    ISSN: 0022-0248
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0022-0248(78)90392-5
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    New electron microscopy for composition analysis of GaAs/Al"xGa"1"-"xAs heterointerfaces
    Amsterdam : Elsevier
    Surface Science 174 (1986), S. 84-87 
    Details
    ISSN: 0039-6028
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0039-6028(86)90390-0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    In–vitro calcium phosphate growth over functionalized cotton fibers (1999)
    Springer
    Journal of materials science 10 (1999), S. 395-400 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Biomimetic growth of calcium phosphate compound on cotton sheets treated with tetraethoxy silane and soaked in simulated body fluid solution was studied using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), micro-Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD). Micro-FTIR and EDAX results show that silicon was coupled to the cotton fiber when cotton was treated with tetra-ethoxy silane (TEOS) at 125°C for 1 h. Calcium phosphate nucleation started to occur on the surface of TEOS-treated cotton fibers upon immersion in 1.5×SBF (simulated body fluid solution) within 3 days and after 20 days, all the fiber surfaces were found covered with a thick and porous coating of calcium phosphate. The Ca and P determined by inductively coupled plasma spectroscopy (ICP) analysis revealed that the Ca/P ratio as well as the amount of calcium phosphate coating depends on the soaking time in SBF solution. © 1999 Kluwer Academic Publishers
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008970913107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Growth of calcium phosphate on surface-modified cotton (1995)
    Springer
    Journal of materials science 6 (1995), S. 597-605 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: A study of the growth of amorphous calcium phosphate on surface-modified cotton fibres by a combination of scanning electron microscopy/electron diffraction X-ray analysis, micro-FTIR and X-ray photoelectron spectroscopy is reported. Cotton fibres phosphorylated by the urea/phosphorous acid method and then soaked in saturated Ca(OH)2 for approximately one week were found to stimulate the growth of a calcium phosphate coating on their surfaces after soaking in 1.5×SBF for as little as 1 day. Ca(OH)2 soaking of the fibres is found to produce highly crystalline clusters lodged in the fibres which were confirmed by micro-FTIR to be calcium phosphite monohydrate (CaHPO3·H2O). In contrast, phosphorylated fibres not subjected to the Ca(OH)2 treatment did not exhibit calcium phosphate growth upon immersion in 1.5×SBF solution. Soaking of the Ca(OH)2-treated fibres with time in the 1.5×SBF solution produced progressively thicker layers of calcium phosphate on the fibres as confirmed by scanning electron microscopy and X-ray photoelectron spectroscopy. In general, calcium phosphate coatings formed over 1 1–5 day period soaking in 1.5×SBF solution appeared to consist of agglomerations of a large number of small spherical particles, while coatings formed after 17 days of soaking were distinctly chunky, thick and non-uniform in appearance. Micro-FTIR indicated that CaHPO3·H2O clusters were still present in cotton samples even after 4 days of soaking, while after 17 days, only the infrared spectrum typical of calcium phosphate was observed. EDX-measured Ca:P ratios of the coatings, although variable, suggested amorphous calcium phosphate. The mechanism of formation of the coating is believed to involve dissolution of the CaHPO3.H2O clusters upon introduction of the Ca(OH)2-treated phosphorylated cotton into the 1.5×SBF solution which elevates the Ca2+ ion concentration in the vicinity of the fibres so stimulating calcium phosphate formation. It is postulated that phosphite groups chemically bound to the cotton fibre surface or a calcium phosphite coating on the fibres act as nucleation sites for calcium phosphate growth in 1.5×SBF solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00121284
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Further studies of calcium phosphate growth on phosphorylated cotton fibres (1995)
    Springer
    Journal of materials science 6 (1995), S. 658-669 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Further studies using scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX), micro-Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and solid state magic angle spinning nuclear magnetic resonance (MAS NMR) techniques of calcium phosphate growth on Ca(OH)2-treated urea/H3PO3- and urea/H3PO4-modified cotton fibres are reported. In the case of the Ca(OH)2-treated urea/H3PO3-modified fibres which have been reported in an earlier paper, further experiments subjecting the urea/H3PO3-modified cotton to alternative soaking treatment procedures to Ca(OH)2 as well as different calcium phosphate growth media such as the alkaline phosphatase-catalysed hydrolysis of disodium p-nitrophenylphosphate to free phosphate have reaffirmed the importance of the Ca(OH)2 treatment step for the stimulus and growth of calcium phosphate growth on the fibres. Studies on cotton phosphorylated by a slightly different method using urea/H3PO4 instead of urea/H3PO3 show that a phosphorylated cotton with similar properties to the urea/H3PO3-modified fibres can be produced. Soaking of these fibres in saturated Ca(OH)2 solution leads to cotton coated with thin layers of calcium phosphate formed by partial hydrolysis of the PO4 functionalities in the phosphorylated cotton which are believed to act as nucleation layers for further calcium phosphate deposition when the fibres are subsequently soaked in 1.5×SBF solution. SEM/EDX studies of the calcium phosphate coatings formed on the Ca(OH)2-treated urea-H3PO4 fibres as a function of soaking time in 1.5 × SBF show that coatings deposit and become noticeably thick after approximately 9 days. XPS studies indicated the presence of carbonate species in the calcium phosphate coating deposited. In common with the calcium phosphate coated Ca(OH)2-treated urea/H3PO3-modified fibres studied earlier, the average EDX-measured Ca: P ratios of the coatings formed on the Ca(OH)2-treated urea/H3PO4 fibres are ∼ 1.60 and give very similar micro-FTIR spectra with evidence of carbonate which suggests that amorphous calcium deficient apatite has deposited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00123448
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Growth of calcium phosphate on phosphorylated chitin fibres (1997)
    Springer
    Journal of materials science 8 (1997), S. 407-412 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Calcium phosphate growth on chitin phosphorylated fibres was studied using scanning electron microscopy and energy dispersive X-ray analysis (SEM, EDX), micro-Fourier transform infrared spectroscopy (FTIR), and solid state magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The C6 chemical shift positions of 13C MAS NMR in the chitin fibres phosphorylated using urea and H3PO4 are obvious indicating that phosphorylation takes place not in the C1 but in the C6 region. Micro-FTIR and 31P MAS NMR suggested that ammonium hydrogen phosphate formed during the phosphorylation procedure. Chitin fibres phosphorylated using urea and H3PO4 and then soaked in saturated Ca(OH)2 solution at ambient temperature, which lead to the formation of thin coatings formed by partial hydrolysis of the PO4 functionalities, were found to stimulate the growth of a calcium phosphate coating on their surfaces after soaking in 1.5×SBF solution for as little as one day. The thin layer after Ca(OH)2 treatment functioned as a nucleation layer for further calcium phosphate deposition after soaking in 1.5×SBF solution. EDX-measured Ca : P ratios of the coatings of Ca(OH)2-treated phosphorylated chitin in 1.5×SBF solution suggested that calcium-deficient apatite was formed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018549404092
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Growth of calcium phosphate on ion-exchange resins pre-saturated with calcium or hydrogenphosphate ions: an SEM/EDX and XPS study (1995)
    Springer
    Journal of materials science 6 (1995), S. 409-419 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Calcium phosphate formed on the surfaces of ion-exchange resins pre-saturated with either Ca2+ or HPO4 2- ions has been studied using a combination of scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) analysis and X-ray photoelectron spectroscopy (XPS). Calcium phosphate was formed at a temperature of 36.5°C via two methods. On Ca2+ or HPO4 2--saturated resins, 1.5xSBF (simulated body fluid) solution was used while on Ca2+-saturated resins only, a novel biomimetic growth medium using the alkaline phosphatase-catalysed hydrolysis reaction of disodium p-nitrophenylphosphate as a source of inorganic phosphate was employed. SEM micrographs showed that the use of 1.5xSBF growth medium solution led to extensive coverage of the resins with calcium phosphate. In contrast, calcium phosphate coatings formed via the alkaline phosphatase-catalysed reaction were of a more variable quality whose morphology could be influenced by adding albumin and collagen to the growth medium. Average Ca:P ratios determined by EDX for coatings formed from the 1.5xSBF growth medium were in the range 1.62–1.74 suggesting that hydroxyapatite had formed. In contrast, Ca:P ratios for the calcium phosphate compounds formed on resins from the alkaline phosphatase reaction were lower at 1.50 suggesting that calcium-deficient hydroxyapatite had formed which was confirmed by inductively coupled plasma (ICP) analysis and X-ray diffraction of isolated amorphous and crystallized powder samples, respectively. Evidence from X-ray photoelectron studies supports a mechanism of formation of the coatings which involves diffusion of the ion out of the interior of the resin to create a high local concentration at the surface thus stimulating precipitation of the coating material on the resin beads.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00120283
    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...