Magnetic Properties of Pr0.7Ca0.3MnO3/SrRuO3 Superlattices

High-quality Pr0.7Ca0.3MnO3/SrRuO3 superlattices were fabricated by pulsed laser deposition and were investigated by high-resolution transmission electron microscopy and SQUID magnetometry. Superlattices with orthorhombic and tetragonal SrRuO3 layers were investigated. The superlattices grew coherently; in the growth direction Pr0.7Ca0.3MnO3 layers were terminated by MnO2- and SrRuO3 layers by RuO2-planes. All superlattices showed antiferromagnetic interlayer coupling in low magnetic fields. The coupling strength was significantly higher for orthorhombic than for tetragonal symmetry of the SrRuO3 layers. The strong interlayer exchange coupling in the superlattice with orthorhombic SrRuO3 layers led to a magnetization reversal mechanism with a partially inverted hysteresis loop.Comment: 12 pages, 4 figure

Social and psychological features of inter-cultural adaptation of Russian students in different universities

Modern globalisation processes, the rapid entry of Russia into the world community, have given more opportunities to interact with various ethnic groups ranging from short-term tourist and business contacts to complex processes of migration and emigration. Migrants and visitors have different goals for staying in a new country, meanwhile the researchers note a lot in common within the adaptation processes of both groups. In particular, tension, stresses and experience of cultural shock during adaptation are observed. Therefore, it is necessary to conduct psychological studies not only of migrants who come for a long time to a new country, but also of visitors, i.e., interns, students who come to study in foreign universitie

Physical and recreational preventing measure technology of disturbances in the cordial and vascular system of students

Our aim is to prove scientifically and to check experimentally physical and recreational technology dosages of motive loads of the students, who have disturbances in cardiovascular system. The carried out researches demonstrate the general positive influence of the developed sport improving technology of dispensing of motive loads of the students, who have changes in cardiovascular system and its influence on somatic healt

Orthorhombic to tetragonal transition of SrRuO3 layers in Pr0.7Ca0.3MnO3/SrRuO3 superlattices

High-quality Pr0.7Ca0.3MnO3/SrRuO3 superlattices with ultrathin layers were fabricated by pulsed laser deposition on SrTiO3 substrates. The superlattices were studied by atomically resolved scanning transmission electron microscopy, high-resolution transmission electron microscopy, resistivity and magnetoresistance measurements. The superlattices grew coherently without growth defects. Viewed along the growth direction, SrRuO3 and Pr0.7Ca0.3MnO3 layers were terminated by RuO2 and MnO2, respectively, which imposes a unique structure to their interfaces. Superlattices with a constant thickness of the SrRuO3 layers, but varying thickness of the Pr0.7Ca0.3MnO3 layers showed a change of crystalline symmetry of the SrRuO3 layers. At a low Pr0.7Ca0.3MnO3 layer thickness of 1.5 nm transmission electron microscopy proved the SrRuO3 layers to be orthorhombic, whereas these were non-orthorhombic for a Pr0.7Ca0.3MnO3 layer thickness of 4.0 nm. Angular magnetoresistance measurements showed orthorhombic (with small monoclinic distortion) symmetry in the first case and tetragonal symmetry of the SrRuO3 layers in the second case. Mechanisms driving this orthorhombic to tetragonal transition are briefly discussed.Comment: 23 pages, 12 figure

Structural features of Ni-Cr-Si-B materials obtained by different technologies

This study considers the structural features of Ni-Cr-Si-B (Ni - base; 15.1 % Cr; 2 % Si; 2 % B; 0.4 % C) materials obtained by different methods. The self-fluxing coatings were deposited by plasma spraying on the tubes from low carbon steel. Bulk cylinder specimens of 20 mm diameter and 15 mm height were obtained by spark plasma sintering (SPS). The structure and phase composition of these materials were investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The major phases of coatings and sintered materials are [gamma]-Ni, Ni[3]B, CrB and Cr[7]C[3]. We demonstrate that the particle unmelted in the process of plasma spraying or SPS consist of [gamma]-Ni-NEB eutectic and also CrB and Cr[7]C[3] inclusions. The prolonged exposure of powder to high temperatures as well as slow cooling rates by SPS provide for the growth of the structural components as compared to those of plasma coatings materials. High cooling rates at the plasma spraying by melted particles contribute to the formation of supersaturated solid solution of Cr, Si and Fe in [gamma]-Ni. The structure of the melted particles in sintering material has gradient composition: the core constituted of Ni grains of 10 μm with [gamma]-Ni-Ni[3]B eutectic on the edges. The results of the experiment demonstrate that the sintering material has a smaller microhardness in comparison with plasma coatings (650 and 850 MPa, respectively), but at the same time the material has higher density (porosity less than 1 %) than plasma coatings (porosity about 2.. .3 %)

Hydrobionts of a freshwater oil-polluted northern lake: bioaccumulation of heavy metals in fish and the rate of ecosystem recovery

The response of phytoplankton, zooplankton, benthic and fish community structure to one of the biggest oil spill in history of Komi Republic (north-west part of Russia) was investigated using data from a long-term survey off the polluted lake. The characteristics of aquatic freshwater communities observed in the study area 10, 11 and 22 years after the spill (1994) were compared to find out the rate of natural recovery of the ecosystem after oil decontamination of bottom sediments. The concentrations of fifteen trace metals (Al, Cr, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Pb, U, Bi, Th) were analyzed in the tissues (muscle) of three fish species. The concentrations of Al (3-309 mg/kg), Cr (0,1-3,71 mg/kg), Fe (8,6-317 mg/kg), and Cu (0,09-99 mg/kg) in fishes from polluted lake resulted in most cases higher than reference thresholds. Quantitative and qualitative indicators of aquatic invertebrates from polluted lake reach those one of unpolluted lake but do not fully recover 22 years after the spill, despite that oil concentration in water column and in bottom sediments was lower than reference tresholds. We conclude that natural recovery rate of aquatic freshwater ecosystems in northern regions after oil pollution is extremely low. The purification of water and bottom sediments of oil-polluted northern water bodies is necessary for stimulation of ecosystem restoration

The personal name in the novel "The curious incident of the dog in the night-time" Mark Haddon

The article deals with the meaning of the personal names in fiction viewed diachronically with the help of etymological dictionaries. It touches social, linguocultural features of the character's names which depend on many factors such as belonging to a definite culture, individual's values, attitudes towards people, society. The historical, national, religious and cultural identities on the social and language levels are analysed in the contemporary British novel of Mark Haddon "The Curious Incident of the Dog in the Night-time

The personal name in the novel "The curious incident of the dog in the night-time" by Mark Haddon = Имя собственное в романе Марка Хаддона "Странный инцидент с собачкой в ночное время"

The historical, national, religious and cultural identities on the social and language levels are analysed in the contemporary British novel of Mark Haddon "The curious incident of the dog in the night-time

The fate of the scientist as a reflection of the epoch: in memory of the first rector of the Kuban State Medical University Nikolai F. Melnikov-Razvedenkov

The paper analyzes the life and professional journey of Nikolai F. Melnikov-Razvedenkov, an outstanding scientist, doctor, and professor, as a reflection of Russian history from the end of the 19th century till the first quarter of the 20th century. The study identifies the role of Nikolai F. Melnikov-Razvedenkov in the development of medical science and the establishment of medical education in the Kuban region. The analysis was conducted with the involvement of archival records, personal correspondence, and scientific works of Nikolai F. Melnikov-Razvedenkov. To solve research problems, the authors used historical descriptive, comparative historical, problem-based chronological, biographical methods, and the method of monographic description. It is shown that the scientist’s fate mirrors the cultural and historical era experienced by the country. The authors define the exclusive role of Nikolai F. Melnikov-Razvedenkov in the establishment of the Kuban Medical Institute. His life path helped reveal the inviolability of medical ethics based on mercy, dedication to the profession, and willingness to serve people. Even in the situation of social upheaval Nikolai F. Melnikov-Razvedenkov found the meaning of his life in scientific work and helping people. His example will allow the modern generation of doctors to gain a greater understanding of the essential purpose of their work

НОВЫЙ СОРТ ТЫКВЫ РОМАНТИКА ДЛЯ ФЕРМЕРСКИХ ХОЗЯЙСТВ, ПРИУСАДЕБНЫХ УЧАСТКОВ И ПРОМЫШЛЕННОЙ ПЕРЕРАБОТКИ

Research work is underway to create pumpkin varieties satisfying the requirements of consumers and the processing industry in Bykovskaya Melons and Gourds Experimental Breeding Station. The aim of the research was to develop pumpkin varieties with high content of dry matter and carotene, resistant to stresses and suitable for use in the food processing industry. Romantica is the variety resulted from breeding program, based on comparative characteristics of ‘Romantica’ and standard variety of Volzhskaya Seraya 92. New pumpkin variety ‘Romanctica’ exceeds the standard in contents of dry matter by 1.2%, sugars by 1.34%, sucrose by 1.73%, carotene by 46.44 mg%, yield by 0.5 t/ha. On the resistance to powdery mildew in artificial infection of sort of Romance has surpassed the standard by 11%, score at 0.4.На Быковской бахчевой селекционной опытной станции ведется работа по созданию сортов тыквы, отвечающих требованиям потребителей и перерабатывающей промышленности. Целью исследований являлось создание сорта тыквы с повышенным содержанием сухого веществ и каротина, устойчивого к стрессовым факторам среды и пригодного для использования в перерабатывающей промышленности. В результате селекционной работы создан сорт тыквы Романтика. По результатам сравнительной характеристике стандарта сорта Волжская серая 92 и сорта Романтика новый сорт превышает стандарт по содержанию сухого вещества на 1,2%, сахаров – на 1,34%, сахарозы – на 1,73%, каротина – на 46,44 мг %, по урожайности – на 0,5 ц/га. По устойчивости к мучнистой росе при искусственном заражении сорт Романтика превзошел стандарт на 11% и 0,4 балла поражения