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21.
The potential and polarization distributions in a planar emitting layer of PLZT-9/65/35 ferroelectric ceramic with a set of conductive strip electrodes on the emitting side and a continuous electrode on the opposite side are studied by numerical methods. The state arising immediately after polarization switching at the leading edge of an applied voltage pulse (i.e., before the polarization charges are screened by free charges) is considered. When the pulsed field strength far exceeds the double coercive field, regions with alternating polarization are found to form in the surface layer between the strips. The normal component of the polarization at its maxima is close to saturation. The electric field on both sides of the surface varies as the polarization vector and reaches 200 kV/cm. At surface microirregularities, the electric field strength is much higher. This means that field emission is responsible for electron escape from the ferroelectric ceramic during pulsed polarization switching. 相似文献
22.
23.
S. V. Ivanov V. V. Trachevskii O. S. Titova L. A. Zozulya 《Russian Journal of Applied Chemistry》2006,79(10):1712-1714
Experimental data demonstrate that a study of accelerated aging can enable prognostication of the working capacity and storage life of polymeric formulations used in aircraft components on the basis of changes in thermogravimetric constants of these polymeric formulations. 相似文献
24.
The not-sufficient-enough conductance of semioxidized protonated polyaniline (PANI) is usually attributed to the presence of ordered quasi-metallic domains surrounded by a poorly conducting amorphous phase. The paper presents experimental results testifying to the existence, in semioxidized PANI, of multilevel redox heterogeneity that crucially effects the conductance magnitude in view of specific topology at which higher-oxidized (conducting) domains are surrounded by less oxidized (poorly conducting) domains and because the PANI conduction is extremely sensitive to the oxidation degree. It is shown experimentally that the interphase doping with metals and degenerate semiconductors of a semioxidized salt of PANI and poly(2-acrylamide-2-methyl-1-propanesulfonic acid) (PAMPSA) with a 1: 2 ratio between PANI and PAMPSA raises the PANI-PAMPSA conductivity by 3–8 orders of magnitude due to the formation near the interface of thin layers whose conductance depends on the work function of the material in contact with PANI-PAMPSA and in extreme cases substantially exceeds the conductance of gold and copper at room temperature. 相似文献
25.
Normal human dermal fibroblasts: proteomic analysis of cell layer and culture medium. 总被引:7,自引:0,他引:7
Federica Boraldi Luca Bini Sabrina Liberatori Alessandro Armini Vitaliano Pallini Roberta Tiozzo Ivonne Pasquali Ronchetti Daniela Quaglino 《Electrophoresis》2003,24(7-8):1292-1310
Proteins present within the cell layer and those released in the cell medium from in vitro cultured normal human dermal fibroblasts were separated and characterized in terms of their isoelectric point and molecular weight, by two-dimensional (2-D) gel electrophoresis. All spots in the synthetic gel were firstly analyzed by the Melanie 3 software and compared with those of breast cancer cells, colorectal epithelial cells, HL60, lymphoma cells, and platelets, already available on-line. From the identification of 144 spots from both the cell layer and the medium, we were able to recognize 89 different proteins, since a certain number of spots represented different isoforms of the same molecule. Identifications were performed by matching with on-line 2-D databases, and by matrix assisted laser-desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS), in order to confirm the identification by matching, or to identify new proteins. The procedure we used allows (i) to design a highly reproducible reference map of the proteome of adult human normal fibroblasts in culture, (ii) to evaluate protein species produced in the cell layer as well as those released in the culture medium, and (iii) to compare data from gel matching with those obtained by MS. This work represents an essential step for a better knowledge of mesenchymal cells, given the widespread use of this cell type in both clinical and experimental investigations. 相似文献
26.
M. Tarasov L. Kuz’min E. Stepantsov I. Agulo A. Kalabukhov M. Fominskii Z. Ivanov T. Claeson 《JETP Letters》2004,79(6):298-303
The voltage response of a thin-film normal-metal hot-electron bolometer based on a SINIS (superconductor-insulator-normal metal-insulator-superconductor) structure to the radiation of a high-temperature Josephson junction in the terahertz frequency region was measured. Bolometers were integrated with planar log-periodic and double-dipole antennas, and Josephson junctions were integrated with log-periodic antennas. Measurements showed that the Josephson junction at a temperature of 260 mK was overheated by the transport current, so that its electron temperature exceeded 3 K at a bias voltage of 1 mV. The maximum response of a bolometer with a double-dipole antenna was observed at a frequency of 300 GHz, which agreed well with the calculated value. The Josephson radiation was observed at frequencies up to 1.7 THz. The voltage response of a bolometer reached 4×108 V/W, and the total noise-equivalent power reached 1.5×10?17 W/Hz1/2. 相似文献
27.
S. E. Kubatkin A. Ya. Tzalenchuk Z. G. Ivanov P. Delsing R. I. Shekhter T. Claeson 《JETP Letters》1996,63(2):126-132
We report on a successful attempt to fabricate a Coulomb blockade electrometer consisting of an ultrasmall YBa2Cu3O7−δ (YBCO) island coupled to two gold electrodes through a high-resistance native surface tunnel barrier. A third electrode placed
near the island was used as an electrostatic gate. Spectra typical for tunneling into the YBCO superconductor were reproducibly
measured. At temperatures below 0.5 K the low-bias conductance was suppressed by the Coulomb blockade. The blockade could
be periodically varied by the gate potential. An external magnetic field of up to 5 T strongly influenced the transport via
the island but without any change in the period of the Coulomb oscillations.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 2, 112–117 (25 January 1996)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
28.
29.
We give a brief account of supersymmetric Born–Infeld theories with extended supersymmetry, including those with partially broken supersymmetry. Some latest developments in this area are presented. One of them is N = 3 supersymmetric Born–Infeld theory which admits a natural off-shell formulation in N = 3 harmonic superspace. 相似文献
30.
N. N. Koval’ Yu. F. Ivanov I. M. Goncharenko O. V. Krysina Yu. A. Kolubaeva K. A. Koshkin 《Russian Physics Journal》2007,50(2):146-152
Phase composition, defect substructure, and mechanical properties of the Ti-Si-N coating deposited on metal and ceramic-metal substrates by electroarc sputtering of the Ti-Si composite cathode in an ionized
nitrogen atmosphere are investigated by the methods of modern materials science. It is established that coatings so formed
with a thickness of ∼1–3 μm are superhard (Hv ∼ 50 GPa), and have the nanocrystalline structure (with crystalline sizes D = 7 nm) based on titanium nitride δ-TiN.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 46–51, February, 2007. 相似文献