Modification of magnetic anisotropy in metallic glasses using high-energy ion beam irradiation

Heavy ion irradiation in the electronic stopping power region induces macroscopic dimensional change in metallic glasses and introduces magnetic anisotropy in some magnetic materials. The present work is on the irradiation study of ferromagnetic metallic glasses, where both dimensional change and modification of magnetic anisotropy are expected. Magnetic anisotropy was measured using Mössbauer spectroscopy of virgin and irradiated Fe₄₀Ni₄₀B₂₀ and Fe₄₀Ni₃₈Mo₄B₁₈ metallic glass ribbons. 90 MeV ¹²⁷I beam was used for the irradiations. Irradiation doses were 5×10¹³ and 7.5×10¹³ ions/cm². The relative intensity ratios D ₂₃ of the second and third lines of the Mössbauer spectra were measured to determine the magnetic anisotropy. The virgin samples of both the materials display in-plane magnetic anisotropy, i.e., the spins are oriented parallel to the ribbon plane. Irradiation is found to cause reduction in magnetic anisotropy. Near-complete randomization of magnetic moments is observed at high irradiation doses. Correlation is found between the residual stresses introduced by ion irradiation and the change in magnetic anisotropy.     

Martensitic transformations in Ti (Ni,Fe) alloys

In this work we used x-ray structural analysis to investigate the martensitic transformations (MTs)B2R andRB19 in Ti(Ni, Fe) alloys containing 1, 2.5, 4, 5 at. % Fe, and the effect of heat treatment on the MT temperatures and sequence. In the majority of cases, it was found that the MTB2R proceeds through a two-phase region (+R). Heat treatment leads to a narrowing of the temperature interval of the existence of the two-phase region, weakly affects the onset temperatures of the MTsB2R T_R andRB19 M_s, and sharply increases the temperature-of the end of the MT M_e. The existence of the two-phase region is related to the two MT channelsB2R andB2B19 initially intrinsic to the allovs of the given compositions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 19–22, December, 1989.     

Room temperature MgI2-catalyzed Friedel–Crafts reaction between electron-rich (het)arenes and ethyl glyoxylate

Magnesium iodide-catalyzed addition of electron-rich (het)arenes to ethyl glyoxylate proceeds at room temperature with high chemoselectivity to afford ethyl 2-(het)aryl- 2-hydroxyacetates in yields up to 95%.     

Ionization penalty in nonlinear Raman neuroimaging

Light-assisted ionization accompanying coherent anti-Stokes Raman scattering (CARS) of ultrashort laser pulses in brain tissue is shown to manifest itself in a detectable blueshift of the anti-Stokes signal. This blueshift can serve as an indicator of ionization processes in CARS-based neuroimaging.     

Determination of the shape of the shocks ahead of a transverse jet injected into a supersonic flow

The three-dimensional shape of the shock wave formed ahead of a sonic jet flowing out into a supersonic flow through the surface of a sharp cone is determined. The shape of the wave in the longitudinal and transverse cross-sections of the model is constructed using schlieren photographs taken for various angles of rotation and freestream Mach numbers M=1.75–3. Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 41–44, March–April, 1998. This research was carried out with financial support from the Russian Foundation for Basic Research (project No. 95-01-00709a).     

Modeling of particle motion in a betatron chamber during the excitation of parametric resonance by free radial oscillations

There is a dynamical modeling of the amplitudes and phases of free radial oscillations of electrons at parametric resonance. The solutions obtained are discussed and compared with the solutions found by other methods.Translated from Izvestiya Vysshikh Uchebnykh Zevedenii Fizika, Vol. 12, No. 4, pp. 39–43, April, 1969.     

Some algorithmic problems for relatively free groups

The paper contains the proof of the algorithmic unrecognizability for two properties of some relatively free soluble groups, as well as the proof of the lack in a certain sense of the recursive enumerability for one more property of such groups. It is also proved that the indecomposability in the class of soluble finitely based varieties of groups is unrecognizable. An example is given of a relatively free soluble group with solvable word problem and with unsolvable identity problem. A result is obtained involving truth-table degrees of the word problem for relatively free soluble groups. Bibliography: 22 titles.     

Synthesis and properties of polyvinylpyrrolidone films containing iron nitrosyl complexes as nitric oxide (NO) donors with antitumor and antiseptic activities

New homogeneous water-soluble polyvinylpyrrolidone composites containing iron sulfur nitrosyl complexes as nitric oxide donors with antitumor and antiseptic activities were synthesized. The morphology of the composites in the solid state was examined by X-ray diffraction and scanning electron microscopy. The study by small-angle X-ray scattering showed that samples of the composites do not contain 10–100-nm aggregates and that iron sulfur nitrosyl complexes are uniformly distributed in polymer matrices. The percentage of NO-releasing iron sulfur nitrosyl complexes in the composites was determined by ESR spectroscopy. An amperometric analysis demonstrated that the polymer composites decompose to yield NO within a few seconds after the dissolution in water without additional thermal and photoactivation. The dependences of the amount of NO and the maximum level of NO release on the duration of the storage of aqueous solutions for all of the synthesized films were determined at pH 7.0. Some of the synthesized polymer composites retain NO-donor activity of the starting pharmacologically active iron nitrosyl complexes and can be recommended to be used as targeted delivery systems of this class of compounds to biological targets.     

Structural and Electric Characteristics of Two-Layer Bi4Ti3O12/(Ba,Sr)TiO3 Thin Films Deposited on a Silicon Substrate by Radio-Frequency Sputtering at Increased Oxygen Pressures

Physics of the Solid State - The 400–450-nm-thick Bi4Ti3O12 thin films with various orientations of crystallites with respect to a normal to the (100)Si substrate plane have been studied. It...