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A spontaneous succession in young abandoned fields
VÍTOVCOVÁ, Kamila
Initial stages of spontaneous succession were studied in two differently aged abandoned field. The main tasks were to answer the following questions: Are the differences in vegetation related to the distance to a source of diaspores? Which species exhibit easier dispersal from the source? The souce of diaspors have a significant effect on the vegetation in the abandoned field and thus on the process of spontaneous succession. The succession leads to meadow vegetation and the succession is rather fast.
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Control system of the electronic shutter
Kostka, František
Application of the electronic shutters lies, in addition to the electronic cameras, mainly in the field of photonics, photometry, holography, and by their exposition of photographic materials in optical laboratories. The contribution delas with the principles of control of the electronic shutter and with the construction of the control systems.
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Technolgy of materials preparation for the high sensitivity infrared detectors
Novotný, Jan ; Zelinka, Jiří ; Franc, J.
Single crystals of triglycine sulphate (TGS) doped with L-alanin, lysin and with Co.sup.2+.sup., Cd.sup.2+.sup. and PO.sub.4./sub..sup.3-.sup. were grown from aqueous solutions by means of slow cooling method. Concentration of doping elements varied from 5 to 20mol. per cent. Morphology, domain structure and P-E hysteresis loops have been investigated. TGS single crystals doped with Co.sup.2+.sup. and PO.sub.4./sub..sup.3-.sup. show the inernal fields as high as 217 kV/m with peculiarities in the hysteresis loops. The best hysteresis loop has been obtained on TGS crystal doped with Lysin and Cd.sup.2+.sup. ions.
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