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51.
A digital holographic interference microscope is designed that allows real-time 3D imaging of phase microobjects and measurement of their morphological parameters. The instrument may find application in medical institutions and research laboratories. 相似文献
52.
I. N. Ogorodnikov V. A. Pustovarov S. I. Omel’kov A. V. Tolmachev R. P. Yavetskiĭ 《Optics and Spectroscopy》2007,102(1):60-67
The paper reports on a study of the luminescence of lithium borate crystals (Li6Gd(BO3)3 doped by Eu3+ and Ce3+ ions, Li5.7Mg0.15Gd(BO3)3: Eu, and Li6Eu(BO3)3) initiated by selective excitation by synchrotron radiation at excitation energies of 3.7–27 eV at 10 and 290 K. Efficient energy transfer between the rare-earth ions Gd3+ → Ce3+ and Gd3+ → Eu3+ was found to proceed by the resonance mechanism, as well as by electron-hole recombination. Fast decay kinetics of luminescence of the Ce3+ activator centers was studied under intracenter photoexcitation and excitation in the interband transition region. The mechanisms involved in luminescence excitation and radiative relaxation of electronic states of rare-earth ions are analyzed, and the energy transfer processes operating in these crystals are discussed. 相似文献
53.
The polarization switching in sinusoidal fields and the pyroelectric properties of Li2?x Na x Ge4O9 (0.2 ≤ x ≤ 0.3) crystals are measured in the temperature range T c ?T ≤ 40 K. The behavior of the P?E hysteresis loops with variations in temperature is investigated for crystals with phase transition temperatures T c < 300 K and T c > 300 K. It is shown that, for crystals with phase transition temperatures T c < 300 K, the temperature dependence of the hysteresis loop exhibits a behavior typical of crystals with second-order phase transitions. The crystals with phase transition temperatures T c > 300 K are characterized by double hysteresis loops in the temperature range T c ?T 1 ≈ 30 K. The correlation between the polarization properties and possible structural transformations of the Li2?x Na x Ge4O9 crystals due to the change in the concentration ratio of Na and Li ions is discussed. 相似文献
54.
A. N. Poddubnyĭ 《Physics of the Solid State》2007,49(2):360-365
The spectra of specular reflection and diffraction of light for a resonant two-dimensional photonic crystal consisting of semiconductor cylinders embedded in a dielectric matrix, as well as the exciton-polariton band structure of this crystal, are studied theoretically. It is shown that specular reflection of light from a photonic crystal can be considerably enhanced by diffraction in the photonic crystal and reflection from its inner boundary with vacuum. 相似文献
55.
I. F. Voloshin A. V. Kalinov L. M. Fisher V. A. Yampol’skiĭ 《Journal of Experimental and Theoretical Physics》2007,105(1):278-282
The evolution of the spatial distribution of the magnetic induction in a superconductor after the action of the alternating magnetic field perpendicular to the trapped magnetic flux has been analyzed. The observed stabilization of the magnetic induction profile is attributed to the increase in the pinning force, so that the screening current density becomes subcritical. The last statement is corroborated by direct measurements. 相似文献
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Baroelectric Emf of an ion-conducting solid-state cell: Elementary processes in a loaded open system
The baroelectric emf of an Ag+-conducting solid-state cell Ag-Ag4RbI5-Ag is investigated. It is shown that, when one of the electrodes of the ion-conducting solid-state cell is loaded, the baroelectric emf of the cell is equal to the sum of the electronic and ionic baroelectric contact potential differences. The electronic (ionic) baroelectric contact potential difference is determined by the work done by the load on changing the electrode volume upon the removal of one electron (ion). The elementary processes responsible for the change in the volume due to the removal of a particle are discussed. 相似文献
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60.
The possibility of doping of surface layers of optical fused silica with silver nanogranules upon heating of a thin Ag film on the silica surface by a CO2 laser beam (P ≈ 30 W, λ = 10.6 μm) is established. The effect of exposure time on the doped layer structure has been investigated. The absorption band of the colloidal solution of Ag in silica has been studied. It is shown that this band is homogeneously broadened and its peak (at 420 nm) corresponds to the small volume filling factor (q < 0.1) at an average granule radius of about 3 nm. Based on the measurements of the radial distributions of the reflectance and refractive index over the doped region at λ = 633 nm, it is revealed that the doped layer is an area-irregular asymmetric step waveguide. 相似文献