Temporal characterization of rock dynamic destruction

Dynamic strength tests published in literature have been analysed by structuraltemporal damage criteria. Parameter τ - incubation time - describing material stability behaviour under high-rate influences have been estimated for Kimachi sandstone, Inada granite and Tage tuff. Two types of dynamic tensile experiments have been used: split Hopkinson pressure bar and spalling. Purely dynamic effect of fracture delay have been observed in the case of Kimachi sandstone and discussed

PROFESSIONAL SELF-DETERMINATION OF THE STUDENT IN THE CONDITIONS OF THE PROFESSIONAL EDUCATIONAL ORGANIZATION

В статье представлен теоретический анализ проблемы профориентационной деятельности обучающегося в условиях колледжа. Исследование проблемы реализации личностного потенциала в профессиональной деятельности остается в центре внимания современной науки. Профессиональное становление с учетом компетентностного подхода является одним из важнейших условий профессионализации личностиThe theoretical analysis of a problem of professional orientation activity of the student in the conditions of the professional educational organization is presented in article. The research of a problem of realization of personal potential in professional activity remains in the center of attention of modern science. Professional formation taking into account competence-based approach is one of the most important conditions of professionalizing of the personalit

Tris(tetra­butyl­ammonium) hexa­kis­(tert-butane­thiol­ato-κS)hepta-μ3-chlorido-μ3-sulfido-hexa­molybdate dihydrate

The octa­hedral cluster core of the anion in the structure of the title compound, (C16H36N)3[Mo6(C4H9S)6(μ3-Cl)7(μ3-S)]·2H2O, has -3 site symmetry. Two μ3-Cl atoms fully occupy positions in the cluster core, while the remaining six positions are statistically occupied by Cl and S atoms in a 1:5 ratio. The fully occupied Cl-atom positions are located on sites with 3 symmetry, and the N atom of tetra­butyl­ammonium cation is located on a site with 2 symmetry. The structure contains also two disordered solvent water mol­ecules, one of which is located on a threefold rotation axis and the other in a general position, both with an occupancy of 0.25. The water mol­ecules are localized in cavities formed by the tetra­butyl­ammonium cations and the tert-butane­thiol­ate groups. The metal clusters are stacked in a cubic close packing arrangement along [001]

METHODS OF PROFESSIONAL ORIENTATION ACTIVITY IN PROFESSIONAL EDUCATION

Статья посвящена проблеме профессионального самоопределения обучающихся. На определённом этапе жизни каждому человеку приходится принимать одно из наиболее важных решений: определиться со сферой образования и выбрать профессию, как показывает практика, многие люди испытывают затруднения в выборе карьерного пути по самым разнообразным причинамArticle is devoted to a problem of professional self-determination of students. At a certain stage of life each person should accept one of the most important decisions: to decide on education and to choose a profession as practice shows, many people experience difficulties in the choice of a career way for the most various reason

Optical spectroscopy of single beryllium acceptors in GaAs/AlGaAs quantum well

We carry out microphotoluminescence measurements of an acceptor-bound exciton (A^0X) recombination in the applied magnetic field with a single impurity resolution. In order to describe the obtained spectra we develop a theoretical model taking into account a quantum well (QW) confinement, an electron-hole and hole-hole exchange interaction. By means of fitting the measured data with the model we are able to study the fine structure of individual acceptors inside the QW. The good agreement between our experiments and the model indicates that we observe single acceptors in a pure two-dimensional environment whose states are unstrained in the QW plain

Optical orientation of spins in GaAs:Mn/AlGaAs quantum wells via impurity-to-band excitation

The paper reports optical orientation experiments performed in the narrow GaAs/AlGaAs quantum wells doped with Mn. We experimentally demonstrate a control over the spin polarization by means of the optical orientation via the impurity-to-band excitation and observe a sign inversion of the luminescence polarization depending on the pump power. The g factor of a hole localized on the Mn acceptor in the quantum well was also found to be considerably modified from its bulk value due to the quantum confinement effect. This finding shows the importance of the local environment on magnetic properties of the dopants in semiconductor nanostructures

The three-dimensional non-anticommutative superspace

We propose two alternative formulations for a three-dimensional non-anticommutative superspace in which some of the fermionic coordinates obey Clifford anticommutation relations. For this superspace, we construct the supersymmetry generators satisfying standard anticommutation relations and the corresponding supercovariant derivatives. We formulate a scalar superfield theory in such a superspace and calculate its propagator. We also suggest a prescription for the introduction of interactions in such theories.Comment: 9 pages, revtex4, v3: some clarifications and references added, version accepted for publication in Phys.Rev.