IBM: parameter symmetry, hidden symmetries and transformations of boson operators

A symmetry of the parameter space of interacting boson models IBM-1 and IBM-2 is studied. The symmetry is associated with linear canonical transformations of boson operators, or, equivalently, with the existence of different realizations of the symmetry algebras of the models. The relevance of the parameter symmetry to physical observables is discussed.Comment: LATEX, 11 pages including 1 eps figure and 1 table prepared as an eps figure; a talk given by A. M. Siirokov at XXII Symposium on Nuclear Physics, Oaxtepec, Morelos, M\'exico, 5--8 January, 1999; to be published in Revista Mex. Fi

The mechanical treatment as a method of Inorganic substances passive

The mechanopassivation effect of metal (II) oxides crystallizing by the structural type of halite under attrition treatment has been found out. For the assessment of the activity decrease the following has been investigated: solution and aquation kinetics of CaO and MgO in water and solutions; spinel and calcium carbide formation kinetics using oxides pretreated mechanically by different modes; kinetics of CO2 fixation and thermal desorption from the pretreated oxides surface; magnesia and phosphate cements set rate. It has been determined that the rate of studied processes with the participation of oxides subjected to attrition treatment reduces by a factor of tens and hundreds. We suppose the cause to be the removal of the rough loosened layers containing the most of defects from the polycrystalline aggregates surface. As that neighboring zones accommodate, their surfaces flatten and the bonding area rises. Separated smallest particles form compact aggregates. The powder density increase and sharper diffraction reflection form confirm the microstructure regulating. Flat surfaces with lower quantity of defects provoke the hypoactivity in regard to water vapors and carbon dioxide. The substances mechanopassivation study can be used to control the reaction rate with the participation of highly active reagents

Youth social policy in the Russian Federation

Modern look of youth social policy in the Russian Federation began to take shape in the 90s, when, due to socio-political and administrative reorganization of the society, the state recognized the need to support young people. Youth is one of the most vulnerable social groups. In this article, it is described on methods and systems analysis techniques, summarizing the results accomplished. The key aspects of youth social policy at the federal and regional levels are also presented. It is proved that the youth is now at risk requiring care of the state. Despite more than 20 years of history of formation, youth social policy is just beginning to take shape and to go beyond the boundaries of the federal legislation. The targeted youth programs of social policy are certainly significant, but require not only testing, but also the introduction by the state of the Russian Federation.peer-reviewe

Scaling characteristics of ULF geomagnetic fields at the Guam seismoactive area and their dynamics in relation to the earthquake

International audienceThe long-term evolution of scaling (fractal) characteristics of the ULF geomagnetic fields in the seismoactive region of the Guam Island is studied in relation to the strong (Ms = 8.0) nearby earthquake of 8 August 1993. The selected period covers 10 months before and 10 months after the earthquake. The FFT procedure, Burlaga-Klein approach and Higuchi method, have been applied to calculate the scaling exponents and fractal dimensions of the ULF time series. It is found that the spectrum of ULF emissions exhibits, on average, a power law behaviour S(f ) ? f -b , which is a fingerprint of the typical fractal (self-affine) time series. The spectrum slope b fluctuates quasi-periodically during the course of time in a range of b = 2.5?0.7, which corresponds to the fractional Brownian motion with both persistent and antipersistent behaviour. An tendency is also found for the spectrum slope to decrease gradually when approaching the earthquake date. Such a tendency manifests itself at all local times, showing a gradual evolution of the structure of the ULF noise to a typical flicker noise structure in proximity to the large earthquake event. We suggest considering such a peculiarity as an earthquake precursory signature. One more effect related to the earthquake is revealed: the longest quasi-period, which is 27 days, disappeared from the variations of the ULF emission spectrum slope during the earthquake, and it reappeared three months after the event. Physical interpretation of the peculiarities revealed has been done on the basis of the SOC (self-organized criticality) concept

The beta-decay of 22Al

In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22Al produced by the fragmentation of a 36Ar primary beam. A beta-decay half-life of 91.1 +- 0.5 ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of 4+ for the ground state of 22Al

Shell-model description of monopole shift in neutron-rich Cu

Variations in the nuclear mean-field, in neutron-rich nuclei, are investigated within the framework of the nuclear shell model. The change is identified to originate mainly from the monopole part of the effective two-body proton-neutron interaction. Applications for the low-lying states in odd-$A$ Cu nuclei are presented. We compare the results using both schematic and realistic forces. We also compare the monopole shifts with the results obtained from large-scale shell-model calculations, using the same realistic interaction, in order to study two-body correlations beyond the proton mean-field variations.Comment: Phys. Rev. C (in press