Band splitting and relative spin alignment in bilayer systems

Influence of relative spin alignment on the band splitting and magnetic excitations in the bilayer correlated systems is studied. Splitting occures to be large or small depending on orientation of staggered spins of layers. Change of the ground state configuration with doping is shown. Behavior of the bilayer splitting in Bi-based cuprate allows to suppose that superconducting transition is accompanied by transformation of spin configuration of system.Comment: 9 pages, 3 figure

The Fermi surface reconstruction in stripe phases of cuprates

Mean-field study of the stripe structures is conducted for a hole-doped Hubbard model. For bond-directed stripes, the Fermi surface consists of segments of an open surface and the boundaries of the hole pockets which appear in the diagonal region of momenta under certain conditions. Segments of the first type are due to one-dimensional bands of states localized on the domain walls. The relation of bands to the doping and temperature dependences of the Hall constant is discussed. In connection with the observation of quantum magnetic oscillations, a systematic search for the electron pockets has been carried out. It is shown that the formation of such pockets in bilayer models is quite possible.Comment: 4 pages, 3 figure

Influence of spin structures and nesting on Fermi surface and a pseudogap anisotropy in t-t'-U Hubbard model

Influence of two type of spin structures on the form of the Fermi surface (FS) and a photoemission intensity map is studied for t-t'-U Hubbard model. Mean field calculations are done for the stripe phase and for the spiral spin structure. It is shown, that unlike a case of electron doping, the hole-doped models are unstable with respect to formation of such structures. The pseudogap anisotropies are different for h- and e- doping. In accordance with ARPES data for La2SrxCuO4 the stripe phase is characterized by quasi-one-dimensional segments of FS at k=(\pi,0) and by suppression of spectral weight in diagonal direction. It is shown that spiral structures display the polarisation anisotropy: different segments of FS correspond to electros with different spin polarisations.Comment: 12 pages, 4 figure

THE DEVELOPMENT OF LOGICAL THINKING IN JUNIOR STUDENTS THROUGH PROJECT-BASED LEARNING

El artículo da una nueva mirada al método de desarrollo del pensamiento lógico en alumnos de tercer año basado en la correlación entre el modelo original y el que hace posible, a diferencia de los métodos tradicionales, desarrollar el pensamiento del habla, las estructuras intelectuales y las operaciones lógicas de los alumnos de manera más efectiva. . Con la ayuda de los enfoques epistemológico, de actividad sistémica y de entorno, se determina una estrategia para desarrollar el pensamiento lógico de los alumnos a través del aprendizaje basado en proyectos que se basa en la correlación entre el modelo original y el original. Asegura el desarrollo efectivo de a) la actividad intelectual de los escolares b) el pensamiento c) la memoria lógica. El estudio demuestra la efectividad de la tecnología presentada, lo que implica 1) sumergirse en el proyecto, así como especificar sus metas y objetivos; 2) organizar y planificar las actividades de los alumnos; 3) resolver las etapas principales del proyecto; 4) llevar a cabo el proyecto y su presentación; 5) evaluar los resultados. Con base en los datos de la investigación, se destacaron los siguientes criterios: análisis, síntesis, comparación, clasificación, generalización y algunos otros criterios que permitieron determinar tres niveles del desarrollo del fenómeno en cuestión. Nuestro método proporciona una mejora significativa de los resultados de la investigación y garantiza la formación de actividades de investigación, informativas, regulatorias y analíticas de aprendizaje universal (ULA). La evaluación de la efectividad y validez del método propuesto se corrobora mediante cálculos para el criterio de Fisher (criterio φ *). Los resultados comparativos de la investigación antes y después del experimento a alto nivel son 3.564. Los valores empíricos obtenidos de φ * están en el área de significancia. H0 se rechaza (el eje de significancia = 1.64–2.31). Por lo tanto, el método en cuestión tiene un grave impacto en el desarrollo del pensamiento lógico a través del aprendizaje basado en proyectos de alumnos menores.O artigo analisa o método de desenvolver o raciocínio lógico em alunos juniores com base na correlação entre o original e o modelo e possibilita, diferentemente dos métodos tradicionais, desenvolver o raciocínio, estruturas intelectuais e operações lógicas dos alunos de maneira mais eficaz. Com o auxílio das abordagens epistemológicas, de atividade sistêmica e do meio, é determinada uma estratégia para o desenvolvimento do pensamento lógico dos alunos por meio da aprendizagem baseada em projetos, baseada na correlação entre o original e o modelo. Garante o desenvolvimento efetivo de a) atividade intelectual das crianças em idade escolar b) pensamento c) memória lógica. O estudo comprova a eficácia da tecnologia apresentada, que implica 1) imersão no projeto, além de especificar suas metas e objetivos; 2) organização e planejamento das atividades dos alunos; 3) elaboração das principais etapas do projeto; 4) realização do projeto e sua apresentação; 5) avaliando os resultados. Com base nos dados da pesquisa, foram destacados os seguintes critérios: análise, síntese, comparação, classificação, generalização e outros critérios que permitiram determinar três níveis de desenvolvimento do fenômeno em questão. Nosso método fornece uma melhoria significativa dos resultados da pesquisa e garante a formação de atividades de aprendizagem universais (ULAs) informativas, regulatórias e analíticas. A avaliação da eficácia e validade do método proposto é corroborada por cálculos para o critério de Fisher (critério φ *). Os resultados comparativos da pesquisa antes e após o experimento em alto nível são 3.564. Os valores empíricos obtidos de φ * estão na área de significância. H0 é rejeitado (o eixo de significância = 1.64-2.31). Assim, o método em questão tem um sério impacto no desenvolvimento do pensamento lógico através da aprendizagem baseada em projetos de alunos juniores.The article takes a new look at the method of developing logical thinking in junior students based on the correlation between the original and the model and making it possible, unlike traditional methods, to develop students’ speech thinking, intellectual structures, and logical operations more effectively. With the aid of the epistemological, systemic-activity, and milieu approaches, a strategy for developing students’ logical thinking through project-based learning that is premised on the correlation between the original and the model is determined. It ensures the effective development of a) schoolchildren’s intellectual activity b) thinking c) logical memory. The study proves the effectiveness of the presented technology, that implies 1) immersing in the project as well as specifying its goals and objectives; 2) organizing and planning students’ activities; 3) working out the main stages of the project; 4) carrying out the project and its presentation; 5) evaluating the results. Based on the research data, the following criteria were singled out analysis, synthesis, comparison, classification, generalization, and some other criteria, which allowed determining three levels of the development of the phenomenon in question. Our method provides for a significant improvement of the results of the research and ensures the formation of research, informational, regulatory, and analytical universal learning activities (ULAs). The assessment of the effectiveness and validity of the proposed method are corroborated by calculations for the Fisher’s criterion (φ*-criterion). The comparative results of the research before and after the experiment at the high level are 3.564. The obtained empirical values of φ * are in the area of significance. H0 is rejected (the significance axis = 1.64–2.31). Thus, the method in question has a serious impact on the development of logical thinking through project-based learning of junior students

Effect of the Frequency of Probiotic Use on the Productivity and Incubation Properties of Eggs of the Meat Production Direction

The use of probiotics Levisel SB Plus and Cellobacterin-T in the amount of 0.50 kg/t of mixed fodder in the diet of young herd replacement of the meat direction during the growing period from 3 to 45 days allowed to get homogeneity by 20.9 and 13.1 % above the analogues of the control group. Probiotic feed additive Levisel SB Plus increased the number of fertilized eggs by 1.96 %, hatchability – by 0.90 %, hatchery waste decreased by 2.7 %, feed costs decreased by 9.6 %. However, the best production results were shown by the group with a similar rate of probiotic Cellobacterin-T introduction, which had these indicators, respectively, of 2.0 %, 1.28, 4.2 and 10.4 %