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991.
A. A. Nechitaĭlov T. K. Zvonareva A. D. Remenyuk V. A. Tolmachev D. N. Goryachev O. S. El’tsina L. V. Belyakov O. M. Sreseli 《Semiconductors》2008,42(10):1249-1254
Catalytic properties of composite amorphous carbon-platinum layers produced by magnetron cosputtering have been studied. The layers were characterized by electron microscopy, IR spectroscopy, ellipsometry, gravimetry, and spectrophotometric chemical analysis. The catalytic activity of the layers was studied in an air-hydrogen fuel cell by measuring its load and power characteristics. 相似文献
992.
Moore J.R. Collings N. Crossland W.A. Davey A.B. Evans M. Jeziorska A.M. Komarcevic M. Parker R.J. Wilkinson T.D. Xu H. 《Photonics Technology Letters, IEEE》2008,20(1):60-62
Polarization-insensitivity is achieved in a reflective spatial light modulator by laying a quarter-wave plate (QWP) at the incident wavelength directly over the mirror pixels of a silicon backplane, and forming a nematic Freedrickcz cell over the QWP to modulate the reflected phase. To achieve the highest drive voltage from the available silicon process, a switched voltage common front electrode design is described, with variable amplitude square wave drive to the pixels to maintain constant root-mean-square drive and minimize phase fluctuations during the dc balance refresh cycle. The silicon has been fabricated and liquid-crystal-on-silicon cells both with and without the QWP assembled; applications include optically transparent switches for optical networks, beam steering for add-drop multiplexers for wavelength-division-multiplexing telecommunications, television multicast, and holographic projection. 相似文献
993.
D. D. Avrov S. I. Dorozhkin Yu. M. Tairov A. Yu. Fadeev A. O. Lebedev 《Semiconductors》2008,42(13):1469-1474
The problem of the appearance of carbon inclusions in single-crystal silicon carbide ingots grown by the modified Lely method (the so-called graphitization of the ingot) is analyzed. It is shown that the process of graphitization of the ingot is not related to a deficit of silicon in the growth cell; in contrast, it is excess of silicon at the growth surface that inhibits the ingot growth rate and gives rise to intense corrosion of the graphite fittings. 相似文献
994.
I. N. Ishchuk 《Measurement Techniques》2007,50(10):1081-1086
A three-dimensional solution of the direct problem of heat conduction when a linear pulsed heat source acts in the plane of
contact of two semibounded bodies is presented. The solution is obtained by the method of finite differences. An example of
the modeling is considered.
__________
Translated from Izmeritel’naya Tekhnika, No. 10, pp. 42–45, October, 2007. 相似文献
995.
996.
997.
A. D. Bulanov P. G. Sennikov V. A. Krylov T. G. Sorochkina L. A. Chuprov O. Yu. Chernova O. Yu. Troshin 《Inorganic Materials》2007,43(4):364-368
Using gas chromatography and high-resolution Fourier-transform IR spectroscopy, we have determined the concentrations of C1–C4 hydrocarbon impurities in isotopically unmodified silicon tetrafluoride before and after fine purification and in 28Si-enriched SiF4. The concentrations of C1–C4 hydrocarbon impurities in silicon tetrafluoride for SiH4 synthesis have been shown to correlate with those in the synthesized silane. 相似文献
998.
Radio-over-fibre (ROF) has received increasing attention for its ability to enable broadband wireless access. This fibre-based wireless access scheme meets the demand for broadband service by integrating the high capacity of optical networks with the flexibility of radio networks (the optical and wireless channels are concatenated with one another). There are, however, impairments that come with this appealing technology. The nonlinear distortion of the optical link and the multipath dispersion of the wireless channel are two of the major factors. In order to limit the effects of these distortions, estimation, and subsequently equalisation, of the concatenated fibre- wireless channel needs to be done. An estimation algorithm for the fibre-wireless uplink in a multiuser code division multiple access (CDMA) environment is presented using pseudonoise training sequences. It has already been shown by Fernando et al. (2001) that identification of the fibre- wireless uplink is possible in a single user CDMA environment. However, the more difficult task of identification in a multiuser spread spectrum environment, which is more realistic, is shown. In the multiuser case, the cumulative effect of multiuser interference, multipath dispersion, nonlinear distortion and noise should all be handled together which makes it more challenging. Numerical evaluations of the developed algorithm show that a good estimation of both the linear and nonlinear systems is possible in the presence of 16 independent users and an signal- to-noise ratio (SNR) of 22 dB. The estimation accuracy increases with the length of the PN sequence. 相似文献
999.
1000.
A. A. Khrushchinskii S. A. Kuten’ N. M. Budevich V. F. Minenko O. M. Zhukova N. K. Luk’yanov 《Journal of Engineering Physics and Thermophysics》2007,80(6):1170-1177
Measurements of the beta-activity of milk, serving as the main source of information on the radioactive contamination of the
environment by the iodine isotope 131I, carried out on a DP-100 radiometer in the early post-Chernobyl period (1986) in Belarus, have been mathematically simulated.
The results obtained allow the conclusion that the indicated measurements should be analyzed again with consideration for
all of the nuclides present in milk.
__________
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 6, pp. 102–108, November–December, 2007. 相似文献