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61.
A. V. Anan’ev M. Yu. Boltoeva L. M. Sharygin M. S. Grigor’ev V. P. Shilov 《Radiochemistry》2006,48(2):119-124
Platinized catalysts on various types of supports were tested in the catalytic decomposition of hydrazine in HClO4 and HNO3 solutions, where the process follows different pathways. In HClO4, the activity of the catalysts supported on a Termoksid ceramic material is higher than that of the catalysts supported on amorphous silica gel. In nitric acid solutions, the trend is reverse. Peptization of the ceramic supports in acid solutions increasing in the order 75% TiO2-25% SnO2 < 75% TiO2-25% ZrO2 ? TiO2 < ZrO2 was observed. In perchloric acid solutions, the catalyst specific activity in the hydrazine adsorption-dissociative decomposition increases with decreasing size of platinum crystallites on the support. In nitric acid solutions, where the hydrazine decomposition proceeds as its catalytic oxidation with nitric acid, the catalyst specific activity decreases with a decrease in the size of the catalyst crystallites, i.e., the catalyst centers located on large crystallites are more active. The results obtained were attributed to the energetic heterogeneity of the surface Pt atoms and various mechanisms of the hydrazine catalytic decomposition in various media. 相似文献
62.
I. A. Sviridov L. M. Kubalova O. Ya. Vasil’eva V. I. Fadeeva 《Inorganic Materials》2006,42(8):867-871
We have investigated solid-state reactions in an equiatomic mixture of Fe and Ge powders during ball milling in a water-cooled high-energy mill under an argon atmosphere. The mechanical alloying products have been characterized by x-ray diffraction, Mössbauer spectroscopy, and calorimetry. The observed sequence of phase formation correlates with the thermodynamic properties of the iron germanides involved. The alloy prepared by ball milling for 2 h consists entirely of nanocrystallites (?15 nm) of the low-temperature, stable, cubic (B20) phase of FeGe. 相似文献
63.
V. E. Kravtsov A. M. Luk’yanov A. B. Pnev S. V. Tikhomirov V. V. Grigor’ev A. K. Mityurev 《Measurement Techniques》2006,49(5):458-465
The state and problems involved in achieving the uniformity of measurements in the field of fiber-optic information transmission
systems and their components are considered. Possible approaches to the solution of these problems and the basic methods and
techniques that have been developed in Russia up to this point are analyzed.
__________
Translated from Izmeritel’naya Tekhnika, No. 5, pp. 30–34, May, 2006. 相似文献
64.
S. E. Aleksandrov V. V. Volkov V. P. Ivanova Yu. S. Kuz’michev Yu. V. Solov’ev 《Technical Physics Letters》2005,31(7):581-583
The characteristics of non-alloy Cr/Au ohmic contacts in planar beam-lead GaAs p-i-n diodes have been studied. The room-temperature reduced contact resistance in the structures studied was 2 × 10−6 Ω cm2. The obtained parameters of p-i-n diodes allow these devices to be used as limiters in radar protection systems. 相似文献
65.
T. A. Lapushkina R. V. Vasil’eva A. V. Erofeev S. A. Ponyaev S. V. Bobashev 《Technical Physics Letters》2004,30(9):724-726
We have studied xenon plasma moving in a supersonic diffuser in external electric and magnetic fields. The main physical parameters of the plasma (electron temperature and density) were determined using specially developed methods based on the theory of continuous optical emission from inert gas atoms. These experimental data are compared to the results of theoretical calculations. Based on an analysis of the results of spectroscopic measurements, a mechanism of plasma ionization is established which is capable of maintaining a high degree of ionization in the supersonic xenon plasma flow. 相似文献
66.
I. A. Podchernyaeva A. D. Panasyuk M. A. Teplenko O. N. Grigor’ev T. V. Mosina R. K. Ivashchenko 《Powder Metallurgy and Metal Ceramics》2004,43(11-12):598-605
The mass transfer kinetics, composition, structure, and properties of coatings, formed by high-frequency electric-spark alloying of 45 and 40X steels with the Ti - Al (3:1, 1:1, 1:3) intermetallics and TiN - AIN (1:1) nitride were studied as a function of the current pulse frequency(ν = 1200 and 1600 Hz). A decrease in ν was found to lead to a higher mass transfer coefficient and higher microhardness and Young’s modulus of the coating as well. This is due to the decrease in the Ti/Al ratio on the surface. The phase composition of intermetallic and nitride coatings differed only insignificantly and did not depend on the value of ν. The main phases of the coatings were Fe - Ti - O and Al - Ti - O solid solutions. The nitride and intermetallic coatings had similar friction coefficients f and wear rates I (f = 0.26 and 0.28, I = 5.4 and 5.9 µm/km), despite the difference in their structure. We can assume that the coating phase composition which defines the composition of the secondary structure under dry friction, is the main factor controlling tribological behavior. 相似文献
67.
Georgi Ilinc?ev 《Journal of Nuclear Materials》2004,335(2):210-216
In recent years, heavy liquid metals have found exercise as possible coolants and targets in the conversion of radioactive elements in accelerator driven systems (ADS). Liquid lead-bismuth eutectic alloy is one of candidates for this using tanks to its suitable nuclear and physical properties. Performed examination was aimed at research of compatibility choice materials for parts of ADS with liquid Pb-Bi eutectic alloy, influence of composition choice materials on their corrosion resistance, influence of temperature and oxygen content. We performed corrosion tests of 1000 h each on approximately 20 types of structural steels (austenitic, ferritic and martensitic) in convection loops with flowing Pb-Bi at 500 and 400 °C and using different oxygen concentrations. The impact of Fe, Cr, Ni, Mn, Si, Al and Mo content on the corrosion stability of these steels was measured without and after preliminary passivation through creating thin spinel or oxide layers on their surface. 相似文献
68.
S. A. Nomoev I. S. Vasil’evskii A. N. Vinichenko K. I. Kozlovskii A. A. Chistyakov E. D. Mishina D. I. Khusyainov A. M. Buryakov 《Technical Physics Letters》2018,44(1):44-46
Low-temperature gallium arsenide (LT-GaAs) films were grown by the method of molecularbeam epitaxy (MBE) at a reduced temperature (230°C) on GaAs(100) substrates and subjected to postgrowth annealing in various regimes. Photoconductive antennas (PCAs) with flag geometry formed on the film surface were characterized by terahertz (THz) response power at various bias voltages. The method of THz spectroscopy was used to study the characteristics of PCAs based on LT-GaAs films annealed in various regimes and the optimum interval of postgrowth annealing temperatures (670–720°C) was established. 相似文献
69.
70.
D. V. Yarygin V. S. Mironov N. P. Solov’ev S. M. Tulin V. I. Yarygin 《Atomic Energy》2000,89(1):546-554
The results of comprehensive experimental investigations of thermionic converters with collectors containing oxygen in an
adsorbed near-surface layer and capable of decreasing the barrier index below 2 eV are presented. A vanadium-doped alloy based
on chromium, which was investigated in a converter in a pair with different emitters consisting of platinum and single crystal
tungsten oriented along the (110) face, was examined as an example of an efficient metal-oxygen system on the collector. The
emission-adsorption properties of electrodes and the output electrical characteristics, obtained under working conditions
of the converter, as well as surface characteristics of the collector, such as the elemental composition temperature, and
others, are described. 6 figures, 21 references.
State Science Center of the Russian Federation—A. I. Leipunskii Physics and Power-Engineering Institute. Translated from Atomnaya
énergiya, Vol. 89, No. 1, pp. 39–48, July, 2000. 相似文献