Detection of а classical signal with unknown parameters in quantum noises of electrodynamic transducer
Detection of а classical signal with unknown parameters in quantum noises of electrodynamic transducer
А.V. Gusev
А strong possiЬility of detecting а classical signal with unknown parameters in the quantum noise of an optical displacement tranducer is considered for the case of an optimally synthesized compensator of excessive interferences which are typical for parametric three-frequency systems.
Show AbstractOn feasibility of suppressing stimulated raman scattering in а plasma ву rapid frequency modulation of pumping radiation
On feasibility of suppressing stimulated raman scattering in а plasma ву rapid frequency modulation of pumping radiation
О.М. Bilak and S.Yu. Nikitin
The problem of suppressing stimulated Raman scattering (SRS) in а plasma under the conditions of laser thermonuclear fusion is discussed. А method of SRS suppression, based on а rapid frequency modulation of pumping radiation, has been proposed.
Show AbstractThermophysical properties of impurity-helium solid phase
Thermophysical properties of impurity-helium solid phase
М.V. Martynenko, V.N. Novikov, А.А. Pelmenev, Е.А. Popov, and Е.V. Shidov
The present paper describes the results of the first experiments on the study of thermophysical characteristics of the impurity-helium solid phase {IHSP} which is formed upon condensation in superfluid helium of а gas-phase helium stream containing the impurity studied. The results oЪtained made it possiЪle to evaluate the thermal diffusivity, thermal conductivity and heat capacity of samples of the neon IHSP in а temperature range of 2.2-3 К. It appeared that the values obtained are close Ьу an order of magnitude, to those oЪtained for liquid helium Hel.
Show AbstractА Mossbauer study of the state of iron atoms during the low-temperature synthesis of cristobalite in the $SiO_2-Fe_2O_3$ system
А Mossbauer study of the state of iron atoms during the low-temperature synthesis of cristobalite in the $SiO_2-Fe_2O_3$ system
V.S. Rusakov, А.М. Bychkov, and G.А. Sukhadolskii
А Mossbauer study has been carried out of the process of low-temperature crystallization of cristobalite under hydrothermal conditions from а gel of the composition Si02 + 0.3 mass percent 57 Fе2 0з. It has been shown that in the original gel the paramagnetic Fe3+ ions are in the form of а diluted impurity in the diamagnetic matrix, with а spin-lattice relaxation oftheir magnetic moments being observed. At the beginning of the synthesis process the iron atoms are reduced to а divalent higl1-spin state with а sixfold oxygen coordination, and then, when cristobalite is formed, there occur the reverse oxidation and the formation of magnetically ordered Fe2 0 3 particles with sizes of 80 А< d < 300 А. No entry of iron atoms into tetrahedral positions of the structure has been observed.
Show AbstractBrief communications the influence of adsorbed hydrogen on the electron gas structure near the surface of a metal
Brief communications the influence of adsorbed hydrogen on the electron gas structure near the surface of a metal
О.S. Erkovich, V.V. Komarov, А.М. Popova, О. Mel'skhaimer, аnd Kh. Neiman
The interaction between positively charged hydrogen ions and а metal surface is studied bу the method of analysis of the structure of the metal electron gas in the presence of а proton. Calculations were performed within the framework of the theory of many-particle density functionals. The energy characteristics of the interaction between а hydrogen ion and the surface and the spatial distribution of the electron gas in the system "metal-adatom" have been calculated.
Show AbstractExcitation of slow solitons in nonlinear tunneling of signals
Excitation of slow solitons in nonlinear tunneling of signals
Yu.N. Karamzin, S.V. Polyakov, and А.Р. Sukhorukov
The present work is concerned with the study of the effect of propagation of signals in waveguides filled with а medium of cublc nonlinearity at а frequency extending outside the band. А numerical modeling has shown that а powerful wave shifts the critical frequency of the waveguide. As а result, а tunneling of one or several slow solitons that do not coincide in frequency with the exciting signal is observed.
Show AbstractSuperfine fields and magnetic moments in heusler alloys $NiMnSb_{1-x}Sn_x$
Superfine fields and magnetic moments in heusler alloys $NiMnSb_{1-x}Sn_x$
Р.N. Stetsenko, V.V. Surikov, S.D. Antipov, G.Е. Goryunov, and Р.V. Chepovskii
The effect of а Fermi level displacement caused when substituting tin for antimony in submetallic ferromagnetic NiMnSЪ1-:r:Sn:r: alloys on sнperfine fields and magnetic moments was studied. The conclusion has been made that superfine fields and local magnetic moments are determined Ьу а partieular atomic environment of а given ion rather than Ьу generalized physical characteristics such as the position of the Fermi level, the lattice parameter, and the Curie temperature.
Show AbstractA series of free exciton lines in transmission spectra of zinc diarsenide
A series of free exciton lines in transmission spectra of zinc diarsenide
V.А. Morozova, Т.V. Semenenya, S.F. Marenkin, О.G. Koshelev, and М.V. Chukichev
А structure corresponding to free exciton states with n = 1, 2, 3 has been detected in zinc diarsenide. The state with n = 3 is observed up to а temperature of 10 К, with n = 2, up to 110 К, and with n = 1, up to 300 К. The exciton binding energy has been determined (17.5 meV).
Show AbstractAbout anomalies of spontaneous magnetization, paraprocess susceptibility, and technical magnetization characteristics of magnetite in low-temperature transformation range
About anomalies of spontaneous magnetization, paraprocess susceptibility, and technical magnetization characteristics of magnetite in low-temperature transformation range
К.Р. Belov, А.N. Goryaga, and L.А. Skipetrova
It is found that in the range of low-temperature transformation of magnetite (Tt = 100-120 К), the spontaneous magnetization decreases sharply, whereas the susceptiЬility of the paraprocess increases. At the same t ime, the technical magnetization characteristics ( the coercive force and the susceptiЬility measured in а weak field) reach extreme values in this domain. This suggests that the lowtemperature transformation in magnetite is а special kind of magnetic phase transition.
Show AbstractShort-range order and characteristic temperature of high-temperature fcc phase of the Mn-21 АТ.% Ga alloy
Short-range order and characteristic temperature of high-temperature fcc phase of the Mn-21 АТ.% Ga alloy
V.М. Silonov and S.Yu. Rodin
The existence of а strong short-range order has Ъееn discovered using the method of diffuse scattering of X-rays in the high-temperature face-centered cublc (FCC) phase of the Mn-21 at. % Ga alloy, its parameters have bееn evaluated, and the characteristic temperature (0п = 200°С) has bееn determined. The elastic constants used for calculating the modulating functions of the dimensional effect have Ъееn calculated with the aid of the model potential technique. The short-range order parameters ai for the first four coordination spheres appeared to bе -0.16, 0.23, 0.12, and -0.24, respectively.
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