排序方式: 共有19条查询结果,搜索用时 0 毫秒
11.
Lasers are finding many applications in mechanical engineering in the USSR. The various types of lasers in use are investigated and the main properties of laser welding and cutting are studied and compared with other forms of these processes. Methods of surface treatment and heat hardening are also investigated. 相似文献
12.
V. Yu. Baranov S. A. Kazakov V. D. Pis'menny A. I. Starodubtsev E. P. Velikhov Yu. A. Gorokhov V. S. Letokhov A. P. Dyad'kin A. Z. Grasiuk B. I. Vasil'yev 《Applied Physics A: Materials Science & Processing》1978,17(3):317-320
Design and operating caracteristics of high pulse repetition rate NH3 laser producing up to 20 W of average output power are described. The NH3 laser, operating in the 12–13 μm region was optically pumped with a high pulse repetition rate TEA CO2 laser. Dependences of the NH3 laser output on the pump energy, ammonia and buffer gas pressures and pulse repetition rate have been studied. The conversion
efficiency of up to 16% has been received. 相似文献
13.
14.
N. V. Znamenskiy T. G. Yukina Yu. V. Malyukin P. N. Zhmurin Yu. N. Velikhov 《Laser Physics》2007,17(4):491-495
For the fist time in Y2SiO5:Pr3+ nanocrystals, the ordered stage in the 1 D 2 luminescence decay curves for Pr3+ ions has been observed at anomalously low doped ion concentration (0.5 at %). This effect is caused by preferred location of the activator ions in the near-surface layer of the nanocrystal that provides the relaxation of elastic tension arising due to the difference of ionic radii of Pr3+ and Y3+ ions. Concentration quenching of Pr3+ luminescence is caused by the cooperative cross-relaxation. 相似文献
15.
N. V. Znamenskiĭ A. Yu. Shashkov Yu. V. Orlov T. G. Yukina Yu. V. Malyukin P. N. Zhmurin Yu. N. Velikhov I. I. Ganina 《JETP Letters》2006,84(4):180-184
In Y2SiO5:Pr3+ nanocrystals, an ordered phase is observed in the 1 D 2 luminescence decay curves of Pr3+ ions at their anomalously low concentration (0.5 at %). This effect is caused by the predominant accumulation of activator ions near the nanocrystal surface, which provides relaxation of the elastic strains arising as a result of the misfit between the ionic radii of Pr3+ and Y3+. The concentration quenching of Pr3+ luminescence is due to cooperative cross relaxation. 相似文献
16.
E. P. Velikhov M. V. Kovalchuk E. A. Azizov V. V. Ignatiev S. A. Subbotin V. F. Tsibulskiy 《Physics of Atomic Nuclei》2015,78(10):1134-1137
The paper presents the results of the system research on the coordinated development of nuclear and fusion power engineering in the current century. Considering the increasing problems of resource procurement, including limited natural uranium resources, it seems reasonable to use fusion reactors as high-power neutron sources for production of nuclear fuel in a blanket. It is shown that the share of fusion sources in this structural configuration of the energy system can be relatively small. A fundamentally important aspect of this solution to the problem of closure of the fuel cycle is that recycling of highly active spent fuel can be abandoned. Radioactivity released during the recycling of the spent fuel from the hybrid reactor blanket is at least two orders of magnitude lower than during the production of the same number of fissile isotopes after the recycling of the spent fuel from a fast reactor. 相似文献
17.
V. L. Arlazarov F. L. Chernous’ko I. V. Gaishun V. A. Gelovani Yu. V. Gulyaev V. A. Il’in N. A. Izobov S. K. Korovin N. N. Krasovskii A. B. Kurzhanskii V. P. Maslov E. F. Mishchenko E. I. Moiseev Yu. S. Osipov Yu. S. Popkov V. A. Sadovnichii T. K. Shemyakina K. A. Valiev E. P. Velikhov 《Differential Equations》2009,45(5):625-626
18.
E. P. Velikhov 《JETP Letters》2005,82(11):690-695
Several decades since the work E. P. Velikhov, Zh. Éksp. Teor. Fiz. 36, 1398 (1959) [Sov. Phys. JETP 9, 995 (1959)] [1] concerning magnetorotational instability was published, great astrophysical interest has been manifested in the mechanism of generating a magnetic field in a rotating well-conducting medium in view of difficulties in the development of the theory of anomalous matter transfer in accretion discs both upon the formation of stars and planets from gaseous conglomerations and upon the formation of a galactic core with a black hole at the center { S. A. Balbus and J. F. Hawley, Astrophys. J. 376, 214 (1991) [2] and G. Ruediger and R. Hollerbach, The Magnetic Universe (Wiley-VCH, Weinheim, 2004) [3]}. Attempts to experimentally observe the magnetorotational instability were successful only for spherical geometry in experiments initially devoted to the verification of geomagnetic dynamo theory {D. R. Sisan et al., Phys. Rev. Lett. 93, 114502 (2004) [4]}. In experiments with liquid sodium in the complete absence of temperature gradients and, therefore, convection, which is very important for the conventional theory of the geomagnetic dynamo, the generation of the magnetic field was obtained due to the development of the magnetorotational instability, which is usually ignored when developing the theory of the origin of the Earth’s magnetic field. The results obtained in this work enable one to develop a theory of geomagnetic dynamo that is primarily based on the magnetorotational instability, which provides a new insight into not only the origin of the Earth’s magnetic field but its evolution in time. 相似文献
19.
Yu. Velikhov I. Pritula I. Ganina M. Kolybayeva V. Puzikov A. N. Levchenko 《Crystal Research and Technology》2007,42(1):27-33
Potassium dihydrogen phosphate (KDP) crystals doped with xylenol orange (XO) and methylthymol blue (MTB) are grown from aqueous solutions by the method of solvent evaporation at room temperature under the conditions of natural convection and by the method of temperature lowering. Studied is the influence of the mother solution acidity on the character of the crystal coloration. The color and coloration intensity of the grown crystals are shown to strongly depend on the solution's pH. It is revealed that the crystal habit changes in the presence of organic dyes. The optical transmission spectra and the luminescence spectra of KDP:XO solutions and of the grown crystals are measured. The effect of thermal treatment and UV‐irradiation on the coloration stability of the crystals is studied. It is found that the laser damage threshold in the prismatic impurity rich colored sectors of KDP:XO is the same as that in the prismatic sectors of pure KDP crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献