Fragmented substructure and crack formation in low-alloy steel

In the work we studied the substructure of 30KhGSA steel after rolling. A relation has been established between the macrofracture of the specimen and its dislocation substructure. The formation and completion of a fragmented substructure with precipitation of carbides at the junctions of fragments during rolling indicate that the lifetime is close to exhaustion. Annealing that partially or completely destroys the fragmented substructure causes microcracks to collapse and heal, eliminates the microcrack nucleation sites, eliminates trajectories of facilitated microcrack growth, which follow subboundaries, and restores the plasticity of the steel.Tomsk State Architectural and Civil Engineering Academy. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 73–82, August, 1994.     

Features of the absorption of 2-to 40-TeV cosmic-ray hadrons in lead

For the first time, experimental data on 2-to 40-TeV hadronic cascades recorded by a lead ionization calorimeter at the Tien-Shan mountain station of the Lebedev Institute of Physics (Moscow) are compared with the results of a present-day simulation based on the GEANT 3.21 code and performed with allowance for the detection procedure. The conclusion that along-flying component appears in high-energy hadronic cascades was drawn previously on the basis of these data. Some special features of the procedure for recording TeV-range hadrons in the calorimeter are considered. It is shown that the averaged hadronic cascades and various features of single cascades having energies below 10 TeV are simulated adequately by using the QGSJET + FLUKA generators of nuclear interactions, but that they are not described by using the GHEISHA generator at lower energies. Some features of the experimentally observed cascades could not be described for cascade energies above 10 TeV.     

9,12-Dibenzothiazolylhypericin and 10,11-Dibenzothiazolyl-10,11-didemethylhypericin: Photochemical Properties of Hypericin Derivatives Depending on the Substitution Site

Investigating the properties of similar but regioselectively differently substituted hypericin derivatives, 9,12-dibenzothiazolylhypericin was synthesized and compared with the recently prepared 10,11-analogue. A significant difference in the ability to generate singlet oxygen and/or reactive oxygen species and different absorption spectra of these two derivatives were observed.     

Numerical finding of the equilibrium interface of liquids in an axisymmetric vessel

A study is made of the problem of numerical determination of doubly connected axisymmetric equilibrium shapes of the interface of two immiscible liquids in an arbitrary axisymmetric vessel under conditions of reduced gravity. Problems of this kind are of practical interest in connection with the study of the behavior of fuel in the tanks of spacecraft [1]. It is assumed that the liquids are homogeneous and incompressible and have a temperature constant throughout the complete volume. In the investigation of the equilibrium of the interface of liquids under conditions of complete or partial weightlessness, it is necessary to take into account the forces of surface tension, which play a decisive part in such a situation. The equilibrium of liquids in a vessel with allowance for surface tension is described by a system of nonlinear equations [2]. In the present paper, the problem is solved by the Kantorovich— Newton iterative method [3], which makes it possible to reduce the nonlinear problem to a succession of linear problems solvable by the method of finite differences.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 134–137, September–October, 1981.I thank I. E. Tarapov and I. I. Ievlev for constant interest in the work and helpful comments.