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  • 1
    Digitale Medien
    Digitale Medien
    Spectroscopic analysis and persistent photon-gated spectral hole burning in LiF:F2− color center crystal (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 2318-2320 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Luminescence and absorption spectra of LiF crystals with F2− color centers (CCs) were studied in the 14–300 K temperature range. The Huang–Rhys factors measured from absorption and emission spectra were equal in magnitude and calculated to be 3.2 and 2.72 at 77 and 300 K, respectively. It was shown that below 40 K inhomogeneous broadening of the zero phonon line of the F2− CC prevails over homogeneous broadening. Inhomogeneous broadening of the zero phonon line was observed to vary from 5 to 15 cm−1 for different crystal preparations. Persistent spectral hole burning stable at room temperature was realized in LiF:F2− crystals. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1406563
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  • 2
    Digitale Medien
    Digitale Medien
    Postsynaptic currents in different types of frog muscle fibre (1982)
    Springer
    Pflügers Archiv 394 (1982), S. 202-210 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Fast and slow muscle fibres ; Synaptic currents ; Cholinesterase inhibitors ; Potential dependency ; Voltage clamp ; ACh-induced noise ; Frogs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Miniature end-plate currents (mepcs) were recorded from fast and slow muscle fibres in two muscles, m. cruralis and m. ileofibularis, under voltage clamp or extracellularly. Both fibre types showed an identical sensitivity to α-bungarotoxin, and an exponential dependence of mepc decay time-constant upon membrane potential, but there were some important differences: i) the rise time and half-time of decay were approximately 3 times longer in slow junctions than in fast ones: ii) inhibition of AChE had a more prominent effect on mepcs recorded in fast fibres while preserving the significant difference in mepc time course between fast and slow fibres; iii) treatment by α-bungarotoxin had a greater effect on mepc time course in slow junctions even in the absence of anticholinesterase; iv) a more prominent variability of mepc time course was observed in slow junctions, especially after treatment by anticholinesterase drugs. Fluctuations of conductance of the postjunctional membrane induced by application of acetylcholine to different frog muscle fibres have been analysed. The autocorrelation function of these fluctuations was exponential and gave information about the mean life-time of single ionic channels and their conductance. There were two main classes of ionic channels: “fast” with mean life-time 2.9 ms and conductance 18.3 pS in single-innervated fast muscle fibres of phasic bundle of m. ileofibularis, m. sartorius and m. cutaneous pectoris; and “slow” −8.3 ms and 12.5 pS correspondingly (t=8–10°C, holding potential −80 mV) in multi-innervated fibres of tonic bundle of m. ileofibularis. An intermediate type of singly-innervated muscle fibres was found in tonic bundles of m. cruralis and m. ileofibularis. The time course of mepcs and life-time of ionic channels recorded in these fibres were intermediate between typical fast and slow mepcs. Simultaneous analysis of mepcs and ACh-induced current fluctuations suggests that the decay of mepcs in typical fast fibres is governed mainly by the closing of ionic channels while the decay of most mepcs in slow fibres is substantially slower than the rate of channel closing. Evidently some additional factors may prolong the effect of ACh-quanta in slow junctions. The relationship between the functional properties of different muscle fibres and rates of sequential steps of postjunctional activation is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00589092
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  • 3
    Digitale Medien
    Digitale Medien
    Direct measurement of the delay time for a neutron in a crystal in the case of the Laue diffraction (2000)
    Springer
    JETP letters 71 (2000), S. 76-79 
    Details
    ISSN: 1090-6487
    Schlagwort(e): 61.12.Ld ; 61.12Bt
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The dynamical Laue diffraction has been studied for a direct beam diffracted from a thin (∼3.5 cm) α-quartz crystal at the Bragg angles close to 90°. It is shown that diffraction occurs at Bragg angles up to 87°. The time-of-flight method is used to measure the time of the neutron presence in the crystal under the diffraction conditions. The time delay for a scattered neutron inside the crystal predicted earlier for the Bragg angles close to 90° confirmed experimentally. The effective velocity of the neutron propagation in a crystal measured at the incident-neutron velocity of 810 m/s and the diffraction angle of 87° equals (43±1) m/s. The result obtained confirms the possibility of increasing, by an order of magnitude, the sensitivity of the diffraction method of determining the dipole moment of a neutron at Bragg angles close to 90° predicted earlier theoretically.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1134/1.568284
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  • 4
    Digitale Medien
    Digitale Medien
    Depolarization of a neutron beam in Laue diffraction by a noncentrosymmetric crystal (2000)
    Springer
    JETP letters 72 (2000), S. 308-311 
    Details
    ISSN: 1090-6487
    Schlagwort(e): 14.20.Dh ; 13.40.Em ; 61.12.Ex
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The depolarization of a neutron beam executing Laue diffraction in a thick (∼3.5 cm) noncentrosymmetric α-quartz crystal is observed. This effect was predicted by us earlier and suggested for measuring the electric dipole moment (EDM) of a neutron. The effect is due to an interaction of the magnetic moment of a moving neutron with a strong crystal electric field, as a result of which the neutron spin rotates in opposite directions for waves of two types excited in the crystal. The effect is studied for neutron diffraction by a system of crystallographic (110) planes at Bragg angles close to π/2, up to 87°. It is shown that, for a crystal of thickness L=3.5 cm, a direct beam initially polarized along the reciprocal lattice vector becomes depolarized upon diffraction, irrespective of the value of Bragg angle, whereas the beam polarized perpendicular to the diffraction plane retains its polarization. The Eτ value determining the sensitivity of the method to EDM is experimentally estimated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1134/1.1328444
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  • 5
    Digitale Medien
    Digitale Medien
    Automated laser system for remote measuring of the sea water fluorescence (1991)
    Springer
    Physical oceanography 2 (1991), S. 387-391 
    Details
    ISSN: 0928-5105
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract A short description of the fluorescent shipboard lidar based on a solid-state laser and two PRAVETS-8 personal computers is presented. Results of field observations are reported.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02197772
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  • 6
    Digitale Medien
    Digitale Medien
    Optical echo spectroscopy and phase relaxation of Nd3+ ions in CaF2 crystals (1998)
    Springer
    Journal of experimental and theoretical physics 86 (1998), S. 156-163 
    Details
    ISSN: 1090-6509
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Accumulated photon echoes have been used to investigate the mechanisms of optical dephasing in CaF2 crystals activated by Nd3+ ions. Tunable picosecond laser radiation, which permits the selective excitation of various Nd3+ optical centers in the 4 I 9/2→4 G 5/2, 2 G 7/2 transition, is used. The optical phase relaxation times measured at temperatures from 9 to 50 K permit determination of the homogeneous widths of the transitions between the low-lying 4 I 9/2 Stark level and three excited 4 G 5/2, 2 G 7/2 levels, and calculation of the constants of the inter-Stark relaxation transitions in the ground and excited multiplets for the rhombic N and M Nd3+ centers in CaF2 crystals. An analysis of the temperature dependence of the homogeneous linewidth of the transitions between low-lying Stark levels of the ground and excited states shows that the mechanism of optical dephasing in the crystals investigated is described well by direct relaxation processes with resonant inter-Stark absorption of one phonon in the ground and excited states. At T=9 K, the homogeneous linewidth Γh in CaF2 crystals is almost an order of magnitude smaller than Γh in disordered CaF2-YF3 crystals. This difference can be attributed to the significantly greater spectral phonon density of states in disordered crystals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1134/1.558480
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  • 7
    Digitale Medien
    Digitale Medien
    Recovery of isometric twitches after glycerol removal (1972)
    Springer
    Cellular and molecular life sciences 28 (1972), S. 424-425 
    Details
    ISSN: 1420-9071
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Выводы 1. Исчезновение одиночных иеометрических сокращений, вызванное отмывкой 110–220 мМ глицерина из изолированных мышечных волокон лягушки, носит обратимый характер. 2. На определенном зтапе огмывки глицерина в ответ на одиночное злектрическое раздражение возникают локальные сокращения волокна, распространяющиеся по волокну со скоростью порядка З ммсек. 3. Выход глицерина резко повышает чувствительхость волокна к механическим воздействиям и часто сопровождается развитием некроза.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02008317
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  • 8
    Digitale Medien
    Digitale Medien
    Mechanical and geometric characteristics of a laminar shell formed by cross winding (1992)
    Springer
    International applied mechanics 28 (1992), S. 92-95 
    Details
    ISSN: 1573-8582
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00847207
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  • 9
    Digitale Medien
    Digitale Medien
    Optimum planning of petrochemical processes (1972)
    Springer
    Chemistry and technology of fuels and oils 8 (1972), S. 641-644 
    Details
    ISSN: 1573-8310
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00717961
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  • 10
    Digitale Medien
    Digitale Medien
    Operation and reconstruction of a high-capacity atmospheric unit (1971)
    Springer
    Chemistry and technology of fuels and oils 7 (1971), S. 365-367 
    Details
    ISSN: 1573-8310
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00714527
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