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61.
Interactions of silicone rubbers designed for electrical engineering applications with aqueous media
L. B. Boinovich A. M. Emel’yanenko A. S. Pashinin 《Protection of Metals and Physical Chemistry of Surfaces》2009,45(1):89-94
Interactions of a number of electrical engineering silicone rubbers with water and aqueous salt, weakly acidic, and weakly basic solutions were studied by measuring contact angles. A mechanism for leakage currents along the surfaces of silicone insulators was proposed. 相似文献
62.
Noncoherent space-time coding: An algebraic perspective 总被引:1,自引:0,他引:1
El Gamal H. Aktas D. Damen M.O. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2005,51(7):2380-2390
The design of space-time signals for noncoherent block-fading channels where the channel state information is not known a priori at the transmitter and the receiver is considered. In particular, a new algebraic formulation for the diversity advantage design criterion is developed. The new criterion encompasses, as a special case, the well-known diversity advantage for unitary space-time signals and, more importantly, applies to arbitrary signaling schemes and arbitrary channel distributions. This criterion is used to establish the optimal diversity-versus-rate tradeoff for training based schemes in block-fading channels. Our results are then specialized to the class of affine space-time signals which allows for a low complexity decoder. Within this class, space-time constellations based on the threaded algebraic space-time (TAST) architecture are considered. These constellations achieve the optimal diversity-versus-rate tradeoff over noncoherent block-fading channels and outperform previously proposed codes in the considered scenarios as demonstrated by the numerical results. Using the analytical and numerical results developed in this paper, nonunitary space-time codes are argued to offer certain advantages in block-fading channels where the appropriate use of coherent space-time codes is shown to offer a very efficient solution to the noncoherent space-time communication paradigm. 相似文献
63.
V. S. Gorelik Yu. P. Voinov G. A. Emel’chenko V. M. Masalov N. I. Yurasov V. V. Gryaznov 《Inorganic Materials》2009,45(6):645-650
We analyze broadband visible reflectivity spectra of opal photonic crystals annealed in an argon atmosphere and air. Scanning electron microscopic examination has shown that the crystals consist of close-packed spheres with a mean diameter in the range 200–290 nm. Incorporation of even small amounts of carbon (?0.5 wt %) increases the density of the opal matrix. The presence of carbon shifts the Bragg reflection peak of the opal and increases its intensity. 相似文献
64.
Emel Karacay 《International Journal of Food Properties》2013,16(5):960-971
Oranges were sanitized, dried, peeled and segmented. Undamaged segments were packed under passive and active MAP with low and high oxygen in PP trays sealed with CPP/OPP film. Overall quality of the segments were monitored for 25 days at 4°C. The results showed that orange segments could be stored under passive and active MAP without significant microbial growth. There were slight changes in acidity and Brix (p ≤ 0.05) with no significant changes in pH and sugar. The hardness increased and color (L, a, b) decreased during storage. Orange segments remained in a commercially viable condition for 10 days under MAP. 相似文献
65.
The problem of semantic clustering of subject-oriented natural language texts is discussed. Based on the theory of Formal Concept Analysis, an approach is proposed to determine the measure of semantic affinity of texts. 相似文献
66.
The results are given of observation of a fundamentally novel phenomenon, namely, the formation of detonation wave of condensation.
Experiments are performed behind shock waves in mixture containing 10–30% carbon suboxide C3O2 in argon. The release of the energy of condensation of highly supersaturated carbon vapor formed upon instantaneous thermal
decomposition of carbon suboxide C3O2 → C + 2CO behind the wave front leads to the amplification of shock wave and its transition to the detonation mode. 相似文献
67.
Capacitance-voltage characteristics of tunneling diodes fabricated by co-implantation of erbium and oxygen in single-crystal (111)Si wafers have been studied. Anomalous enhancement of the p-n-junction capacitance with increasing reverse bias has been observed at certain temperatures depending on the implantation dose. The rise in capacitance (decrease in the space charge region width) is associated with the formation of deep levels of high density in the band gap of n-layer of the p-n junction and electron emission from these levels in the space charge region with increasing voltage. The obtained results show that the parameters of the defects responsible for the levels depend on the erbium and oxygen implantation doses. 相似文献
68.
O. A. Emel’yanov 《Technical Physics Letters》2001,27(8):679-682
A stationary temperature state of a polar polymer dielectric exposed to an electric field is studied. A special feature of
the dielectrics of this type is the presence of a maximum in the loss factor ε″(T) above the glass transition temperature. Using an approach based on the Kirkwood formula for ε″(T), exact solutions to a nonlinear model problem are obtained. These solutions show the multiplicity of the stationary temperature
states and the surface of these states in the “load-ambient temperature” space of parameters exhibits a topological singularity
of the “fold” type. 相似文献
69.
Electroluminescence (EL) of erbium-and oxygen-doped Si:(Er,O) diodes at λ=1.00–1.65 μm has been studied in the p-n junction breakdown and forward current modes. The EL was measured at room temperature from the front and back surfaces of
the diodes. A peak corresponding to the absorption band edge of silicon was observed in the EL spectra of some diodes in the
p-n junction breakdown mode. The peak is associated with the injection of minority carriers from the metal contact into silicon,
with subsequent band-to-band radiative recombination. The band-to-band recombination intensity increases sharply on reaching
a certain current density that depends on the fabrication technology. This threshold current density decreases with the temperature
of post-implantation annealing of Si:(Er,O) diodes increasing in the range 900–1100°C.
__________
Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 36, No. 4, 2002, pp. 453–456.
Original Russian Text Copyright ? 2002 by Emel’yanov, Nikolaev, Sobolev. 相似文献
70.
Huseyin Cankaya Reyhane Kilci Alphan Sennaroglu Emel Yilgor Iskender Yilgor 《应用聚合物科学杂志》2010,117(1):378-383
Novel, polymeric UV‐to‐visible converters were prepared by doping elastomeric poly(ether‐urethaneurea) copolymers with 5–25% by weight of ErCl3 6H2O, corresponding to Er3+ concentrations of 2.19 to 10.86% by weight. When excited in the UV at 355 nm, the doped films generated a very broad, continuous visible luminescence between 400 and 750 nm. Preparation and spectroscopic characterization of the samples are discussed in detail. The color coordinates, color temperature, color rendering index of the samples, and the degree of overlap of their emission bands with the spectral response of the eye were determined. The color rendering index of samples is in the 57–70 range. The sample containing 2.19% by weight of Er3+ was found to give the color coordinates closest to the white‐source region and the highest color rendering index. The color temperatures of the samples were in the 5093–5540 K range. Overlap between the emission bands and the spectral response of the eye improved with increasing erbium concentration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献