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111.
112.
Phase transformations in particles of ultrafine powders of graphite, hexagonal boron nitride, and quartz during rapid heating and cooling by passage through a laser beam were investigated. A continuous infrared laser with a wavelength of 10.6 μm was used as a heat source through which the powders were recycled several times. Methods of concentrating the product phases are described. Particles of diamond, carbides, cubic boron nitride, koesite and stishovite were obtained in the mixed products. 相似文献
113.
A new method is described for transferring phase contrast in electron microscopy without artefacts due to oscillations of the phase contrast transfer function (PCTF). This is carried out by in situ image synthesis of two or three exposures transferred with complementary PCTF. The essence of the technique is to use optimized transfer attenuation functions to cut off the negative parts of PCTF. 相似文献
114.
Translated from Atomnaya Énergiya, Vol. 67, No. 2, pp. 97–100, August, 1989. 相似文献
115.
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117.
V. L. Ozol' L. F. Kandyba N. T. Bychenkov L. A. Zbarskii B. E. Koropov 《Metallurgist》1989,33(8):156-156
Lenin Dnepropetrovsk Pipe Plant. Translated from Metallurg, No. 8, p. 39, August, 1989. 相似文献
118.
Kuh S.S. Strozier T.A. Ryan C.R. 《Selected Areas in Communications, IEEE Journal on》1989,7(9):1462-1469
A continuous phase quadrature phase shift keyed (CPQPSK) modulation technique is presented. This method utilizes a conventional QPSK modulator and a phase trajectory converter to approximate M =4, h =1/4 continuous phase signal and allows low cost, low complexity, and high rate (>1 Gbit/s) CPM modem implementation for bandwidth efficient transmission through nonlinear satellite channels. Using a communications analysis computer program it has been found that CPQPSK has 99 percent out-of-band power of 0.8R (MSK has 99 percent out-of-band power of 1.2 R where R is defined as bit rate), continuous phase trajectories, and nearly constant envelope amplitude. Simulation of realistic hardware designs indicate that the CPQPSK will require an Eb /No of 14 dB to achieve a bit error rate (BER) of 10-6. Forward error correcting techniques using block codes with an overhead of 10 percent indicate that the Eb /No requirements can be reduced to 11.2 dB for 10-6 BER 相似文献
119.
A. M. Pristrem N. I. Danilovich V. A. Labunov 《Journal of Engineering Physics and Thermophysics》1987,53(6):1464-1472
By using integral transform methods, an approach is developed to the solution of a problem on the temprature distribution in multilayer structures heated by cw scanning laser radiation, with phase transitions in the layers taken into account.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 6, pp. 1000–1010, December, 1987. 相似文献
120.
Cavagnino A. Lazzari M. Profumo F. Tenconi A. 《Industry Applications, IEEE Transactions on》2002,38(6):1517-1524
The aim of this paper is the comparison of the axial flux (AF) structures versus the conventional radial flux (RF) structures for permanent-magnet synchronous motors. The comparison procedure is based on simple thermal considerations. Two motor typologies are chosen and compared in terms of delivered electromagnetic torque. The comparison is developed for different motor dimensions and the pole number influence is put into evidence. The paper reports the complete comparison procedure and the related results analysis. The obtained results show that, when the axial length is very short and the pole number is high, the AF motors can be an attractive alternative to the conventional RF solutions. 相似文献