ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • Crystal structure  (1)
  • Electrical impedance  (1)
  • Springer  (2)
  • American Society of Hematology
  • 1995-1999  (2)
  • 1
    Electronic Resource
    Electronic Resource
    An infrared spectroscopic and single-crystal X-ray study of malayaite, CaSnSiO5 (1999)
    Springer
    Physics and chemistry of minerals 26 (1999), S. 546-553 
    Details
    ISSN: 1432-2021
    Keywords: Key words Malayaite ; Infrared spectroscopy ; Crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Abstract Powder infrared spectroscopy and X-ray diffraction techniques on single crystals were used to study the thermal behaviour of malayaite, CaSnSiO5. Infrared spectra show a discontinuity in the temperature evolution of phonon frequencies and absorbance near 500 K. However, crystal structure data collected at 300, 450, 550, 670, and 750 K show no evidence of a symmetry-breaking phase transition and no split positions. The most obvious change with heating is a tumbling motion of the SnO6 octahedra and an increase of the anisotropic displacement factors of Ca. The thermal evolution of the mean-square vibrational amplitude of the Ca atom shows a pronounced change in slope near 500 K. The evidence suggests that the 500 K anomaly in malayaite is more similar in character to the 825 K (β-γ) transition as opposed to the 496 K (α-β) transition in synthetic titanite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002690050218
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Electrical impedance analysis in plant tissues: on the biological meaning of Cole-Cole α in Scots pine needles (1995)
    Springer
    European biophysics journal 24 (1995), S. 99-106 
    Details
    ISSN: 1432-1017
    Keywords: Pinus sylvestris L. (Scots pine) ; Electrical impedance ; Membrane capacitance ; Transmission line ; Cole-Cole α ; Air space
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Electrical impedance spectra (80 Hz–1 MHz) in Scots pine needles were found to be characterized by spectrum skewness in the Cole-Cole plot. These spectra were subjected to analysis with two distributed models: (i) the Cole-Cole function and (ii) an equivalent circuit which takes account of the presence of air spaces within the needles (Model-A). In analysis with untreated needles (without artificial infiltration with water), Model-A fitted better than the Cole-Cole function to the experimental data. After infiltration of water into the needles, the extent of spectrum skewness was substantially decreased compared with the pre-infiltration condition and the Cole-Cole function fitted better than Model-A to the measured impedance data. The Cole-Cole α decreased from 0.47 in non-infiltrated needles to 0.42 in the infiltrated needles. The exceptionally large value of α in non-infiltrated needles can be explained by the presence of air spaces, which produce transmission line properties in the mesophyll. In support of the validity of Model-A, this new model provided specific membrane resistances of 1190 ± 83 Ω cm2 in cold hardened and non-hardened needles respectively. These specific membrane resistance are comparable with previous reports of membrane resistances in other biological systems. It is concluded that in this exceptionally spongy tissue, Cole-Cole α is likely to be due to the effects of the transmission line properties of cells which are surrounded by air spaces and only thin cell walls outside the insulating cell membranes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00211405
    Location Call Number Expected 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...