Reactions of phenyl- and trimethylsilylphenylphosphines with thiobenzophenone

Conclusions The reaction of phenyl- and trimethylsilylphenylphosphines with thiobenzophenone with a 11 reagent ratio proceeds with the formation of secondary phosphines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2116–2117, September, 1984.     

Plane Closed Trajectories on Certain Manifolds with Rotation Metric

Trajectories on spherical and toroidal manifolds are studied by methods of infinitesimal and global geometry.     

Energy spectrum and quantum magnetotransport in type-II heterojunctions

Specific features of the energy spectrum of a separated type-II heterojunction in an external magnetic field are studied theoretically and experimentally. It is shown that, due to hybridization of the states of the valence band of one semiconductor and the conduction band of the other semiconductor at the heterointerface, there are level anticrossings, which produce quasigaps in the density of states in a nonzero magnetic field. The experimental results of magnetotransport studies for the GaInAsSb/p-InAs quaternary solid solutions with different doping levels are shown to agree well with the results of simulation, and specific features of the energy spectrum of separated type-II heterojunctions are established.     

The NUCLEON experiment: The current status

The main purpose of the NUCLEON experiment is direct measurements of the energy spectra of cosmic rays in the range 10¹¹–10¹⁵ eV with the use of the lightweight facility during a prolonged orbital flight. The energy is determined using a technique based on the measurement of the spatial density of secondary particles produced in the initial event of inelastic interaction. The schematic diagram of the NUCLEON facility, the current status of the project, the results of testing the prototype, and plans are presented.     

Formation of mismatched layers in pentagonal nanorods

A new mechanism is presented to model the relaxation phenomena in pentagonal nanorods (PNRs) – elongated multiple twinned crystals. It is demonstrated that a shell possessing crystal mismatch with respect to the PNR core region will reduce the internal energy of the PNR associated with wedge disclinations of strength 7°20′ lying along the PNR axis. We predict the existence of an optimal magnitude for core/shell crystal lattice mismatch and an optimal shell thickness providing maximum energy release for this mechanism of mechanical stress relaxation. The considered relaxation mechanism can be realized by the diffusion of impurities in the shell region without change of the PNR radius or by growth of a thin mismatched shell layer with the corresponding thickening of PNR. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Static statement of the stability problem under creep

In technological processes of rod bending, the critical time is determined [1] by the criterion of unbounded increase A → ∞ in the bent axis amplitude, which is equivalent to the requirement A ? A ₀, where A ₀ is value of the amplitude at the initial time t = 0. In this case, the mathematical models of the process of buckling of rods and plates [2] are constructed in the framework of the theory of small displacements. This contradiction can be removed by the assumption that the critical state is realized for deflections A of the order of several A ₀, i.e., at the time instant corresponding to a sharp increase in displacements. Naturally, this assumption is of local character, because the instant of the transition to the accelerated increase in deflections depends on specific conditions such as, for example, the support conditions, the creep coefficient, the type of the system imperfectness, the value of A ₀, and the eccentricity of the load application.In what follows, we show that, in the case of longitudinal bending (buckling), the time instant directly preceding the beginning of the catastrophic increase in deflections can be determined by the variation in the phase volume of the system.