bluuebunny/crossref_metadata_2025 huggingface dataset:
Влияние частоты переменного электрического поля на температурные спектры импеданса керамического мультиферроика LuFe-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=-
Authors: Алиев Р.А. , Гамзатов А.Г. , Гаджиев Г.М. , Абакарова Н.С. , Кауль А.Р. , Маркелова М. , Эмирасланова Л.Л.
Published: May 2018

AbstractTemperature impedance spectra are measured on LuFe_2O_4 ceramic multiferroics over a temperature range of 100–400 K, upon applying a sinusoidal voltage with a frequency varying between 20 Hz and 120MHz. At signal frequencies of 30–70 MHz, spectra exhibit features such as an abnormal positive temperature resistance coefficient within the temperature range of 200–260 K, which are interpreted in the context of the generalized barrier model.
Фрустрации и упорядочение в магнитных системах различной размерности
Authors: Кассан-Оглы Ф.А. , Прошкин А.И.
Published: May 2018

AbstractBased on the exact and numerical calculations within the Ising and Potts models on lattices of various types and dimensions (one-dimensional, square, triangular, hexagonal, kagome, simple cubic, and body-centered cubic), magnetic orderings, phase transitions, and frustrations were investigated, taking into account the exchange interactions between magnetic moments at the nearest and next-nearest nodes and an external magnetic field. The causes of the occurrence of frustrations are found, and the essential features of the behavior of frustrated systems that distinguish them from the nonfrustrated systems are determined.
Монте-Карло-исследование влияния начальных состояний и дефектов структуры на неравновесное критическое поведение трехмерной модели Изинга
Authors: Прудников В.В. , Прудников П.В. , Маляренко П.Н.
Published: May 2018

AbstractThe effect of various initial magnetizations m _0 and structural defects the nonequilibrium critical behavior of the three-dimensional Ising model is numerically studied. Based on an analysis of the time dependence of the magnetization and the two-time dependence of the autocorrelation function and dynamic susceptibility, the significant effect of initial states on relaxation magnetizations and aging effects characterized by anomalous relaxation inhibition and correlation in the system with increasing waiting time was revealed. The fluctuation–dissipation theorem violation was studied, and the values of the limit fluctuation–dissipation ratio (FDR) are calculated. It is shown that two universality subclasses can be distinguished in the nonequilibrium critical behavior of the three-dimensional Ising model with random initial magnetization m _0 These subclasses correspond to the system evolution from the high-temperature ( m _0 = 0) and low-temperature ( m _0 = 1) initial states with limit FDRs characteristic of these states.
Влияние структурных неоднородностей и газообразующих примесей на функциональные свойства высокочистых редкоземельных металлов
Authors: Чжан В.Б. , Терёшина И.С.
Published: May 2018

AbstractRare-earth metals (REM) gadolinium and dysprosium, and also the Gd–H and Dy–H systems in which magnetic order–order and order–disorder phase transitions are accompanied by significant magnetocaloric effect, have been studied. The materials have been prepared in various structural states. It is stated that there is a substantial difference of their functional properties in the dependence on the features of the structural state and also on the existence of a gas-forming impurity. It has been proved experimentally and theoretically that the Curie temperatures of Gd samples with grain sizes of ~200 nm increases as a result of hydrogenation, while the magnetic phase transition temperatures of Dy are almost unchanged Inhomogeneities.
Особенности формирования магнитокалорических явлений в системах Mn-=SUB=-1-t-=/SUB=-Ti-=SUB=-t-=/SUB=-As и Mn-=SUB=-1-x-=/SUB=-Cr-=SUB=-x-=/SUB=-NiGe
Authors: Вальков В.И. , Грибанов И.Ф. , Тодрис Б.М. , Головчан А.В. , Митюк В.И.
Published: May 2018

AbstractThe magnetocaloric properties of the systems exhibiting magnetic (paramagnetism (PM)–ferromagnetism (FM)) and structural (hexagonal lattice–orthorhombic lattice) transitions separated (overlapped) in temperature are analyzed in terms of a model of interacting parameters of magnetic and structural orders. It is shown that the magnetocaloric characteristics of the system can increase or decrease during overlapping of the structural ( P 6_3/ mmc – P _ nma ) and magnetic (PM–FM) transitions in the dependence of the character of combination of the low-symmetric orthorhombic ( P _ nma ) and high-symmetric hexagonal ( P 6_3/ mmc ) phases with a ferromagnetic order.
Исследование структуры и магнитных свойств сплавов Fe-=SUB=-8-=/SUB=-Rh-=SUB=-8-x-=/SUB=-Z-=SUB=-x-=/SUB=- (Z=Mn, Pt, Co; x=1, 2 и 3) первопринципными методами
Authors: Павлухина О.О. , Соколовский В.В. , Бучельников В.Д. , Загребин М.А.
Published: May 2018

AbstractThe results of first-principles studies of the structure and magnetic properties of Fe–Rh–Z alloys conducted using the VASP package are reported. The magnetic moments and lattice parameters are determined, and the possibility of existence of stable tetragonal distortions in Fe–Rh–Z alloys with various magnetic configurations set by the level of doping with Mn, Pt, and Co is examined. It is demonstrated that the equilibrium lattice parameter and the type of magnetic ordering change with the concentration of the third element.
Структурные, магнитные, электронные и термодинамические свойства сплавов Гейслера Pd-=SUB=-2-=/SUB=-MnZ (Z=Ga, Ge, As): исследование ab initio
Authors: Мирошкина О.Н. , Загребин М.А. , Соколовский В.В. , Бучельников В.Д.
Published: May 2018

AbstractThe results of examination of the structural, magnetic, electronic, and thermodynamic properties of Pd_2MnZ (Z = Ga, Ge, As) Heusler alloys obtained in ab initio and Monte Carlo modeling are presented. It is demonstrated that a stable martensitic state is possible for Pd_2MnGa and Pd_2MnAs alloys. The equilibrium lattice parameter increases in the considered series of alloys with the number of valence electrons per atom ( e / a ). The Curie temperature of Pd_2MnZ (Z = Ga, Ge, As) alloys is determined using the calculated parameters of exchange interaction and total magnetic moments.
Магнитные и упругие колебания в кристаллах марганец-цинковой шпинели в зависимости от константы анизотропии
Authors: Котов Л.Н. , Северин П.А. , Власов В.С. , Безносиков Д.С. , Котова Е.Л. , Шавров В.Г.
Published: May 2018

AbstractThe amplitudes of magnetic and elastic vibrations for Mn_0.61Zn_0.35Fe_2.04O_4 spinel crystalline slab are calculated by solving the equations describing the magnetic and elastic dynamics. The anisotropy constants, magnetization, second-order elastic constants and magnetoelastic coupling constants for a studied crystal are expressed as the functions of temperature. The magnetization vector and elastic shear components are found as the functions of the first magnetic anisotropy constant at different values of an external constant magnetic field greater than a saturation field. The procession patterns for normally and tangentially magnetized slabs are displayed for two values of the first anisotropy constant. High absolute values of the first anisotropy constant are shown to refer to reorientation of the magnetization vector.
Низкотемпературные магнитные свойства аморфного ферромагнитного микропровода из сплава Fe-Si-B в стеклянной оболочке и без нее
Authors: Барабан И.А. , Емельянов А.В. , Медведская П.Н. , Родионова В.В.
Published: May 2018

AbstractThis work presents results of investigations of low temperature magnetic properties of microwires, fabricated by the Ulitovsky–Taylor method from Fe–Si–B alloy. Influence of the glass coating presence on the magnetostatic properties was shown at room temperature and at 2 K. Conclusions about the peculiarities of temperature dependence of the magnetic moment, measured in low and high magnetic fields (10 Oe–5 kOe) in the temperature range from 2 to 300 K for a sample with partially reduced fabricated processinduced stress by removing the glass, were made.
Структурные аспекты деформационной аморфизации кристаллического сплава Ti-=SUB=-50-=/SUB=-Ni-=SUB=-25-=/SUB=-Cu-=SUB=-25-=/SUB=- при кручении под высоким давлением
Authors: Сундеев Р.В. , Шалимова А.В. , Глезер А.М. , Печина Е.А. , Горшенков М.В.
Published: May 2018

AbstractThe evolution of the structure of the Ti50Ni25Cu25 crystalline alloy during high-pressure torsion at room temperature has been studied. The torsional moment variation curve as a function of the strain value was fixed in situ, which allowed directly observing the transition of the material from the crystalline state to the amorphous state during the HPT. It was found that the amorphization of the material in the course of the HPT begins on the grain boundaries and fragments of the crystalline phase. Amorphized boundaries form a “grain-boundary carcass” in the cells of which the high-defect nanocrystalline phase is formed. Growth of deformation leads to broadening of the “grain-boundary carcass,” loss of stability of the crystalline phase, and, as a consequence, to the phase transition “crystal → amorphous” state.
Компьютерное моделирование критического поведения двумерной слаборазбавленной антиферромагнитной модели Поттса на треугольной решетке
Authors: Бабаев А.Б. , Муртазаев А.К. , Атаева Г.Я. , Ризванова Т.Р. , Джамалудинов М.Р.
Published: May 2018

AbstractThe critical behavior of a two-dimensional weakly diluted antiferromagnetic Potts model with spin states q = 3 on a triangular lattice is computationally simulated. The systems with periodic boundary conditions were calculated, when spin concentrations p were 1.0 and 0.9. Systems with linear dimensions L × L = N and L = 9–144 were considered. Static critical exponents of heat capacity α, the susceptibility γ, the order parameter β, and critical exponent ν for a correlation radius are calculated based on a theory of finite-dimensional scaling.
Плотность состояний и структура основного состояния модели Изинга на решетке Кагоме с учетом взаимодействия ближайших и следующих соседей
Authors: Магомедов М.А. , Муртазаев А.К.
Published: May 2018

AbstractPhase transitions and thermodynamic properties have been studied in the two-dimensional antiferromagnetic Ising model on a Kagome lattice by the Monte Carlo method with consideration for both nearest- and next-nearest-neighbor interaction. Using the histogram data analysis method, it has been shown that the studied model is characterized by a second-order phase transition. The temperature dependence of thermodynamic parameters has been revealed to exhibit abnormal behavior.
Эффект запаздывания при импульсном возбуждении актюатора на основе быстрозакаленного сплава Ti-=SUB=-2-=/SUB=-NiCu с термоупругим мартенситным переходом
Authors: Антонов Р.А. , Каманцев А.П. , Коледов В.В. , Коледов Л.В. , Кучин Д.С. , Лега П.В. , Морозов Е.В. , Орлов А.П. , Сиваченко А.П. , Шавров В.Г. , Шеляков А.В.
Published: May 2018

AbstractThe pulse response of the actuator based on rapidly quenched Ti_2NiCu alloy with a thermoelastic martensitic transformation and the shape memory effect is studied experimentally. The mechanical response of the actuator cooled by running water is preserved when the duration of the excitation (activating) electric pulses decreases to 2 ms. High-speed activation is accompanied by a delay in the mechanical pulse in comparison with the excitation electric pulse. The minimum duration of the mechanical pulse, taking into account the delay, was 8 ms, which corresponds to a frequency of 125 Hz with periodic activation. Estimates show that the delay time includes both the time of mechanical inertia and the time of thermal inertia associated with heat transfer. The possible limitation of the rate of activation due to kinetic phenomena during the thermoelastic martensitic transition is evaluated.
Калибровочная теория стекольного перехода в трехмерной XY-модели с вмороженным беспорядком
Authors: Васин М.Г. , Винокур В.М.
Published: May 2018

AbstractThe gauge theory of phase transitions in a three-dimensional XY-model with a hardened disorder is considered. It is shown that the topological phase transition occurring in the vortex subsystem of this model is a transition in the state of spin glass.
Электронная и магнитная структура интеркалированных пленок графена
Authors: Дунаевский С.М. , Лобанова Е.Ю. , Михайленко Е.К. , Пронин И.И.
Published: May 2018

AbstractAb initio calculations of the electron spectrum of the graphene–cobalt–nickel system were performed in the slope of the spin density functional theory (SDFT). Dispersion curves E _σ n (k) are presented; they were used to determine partial and total densities of valence electron states, and also magnetic moments of all atoms in the supercell. Energy position of the “Dirac cone” defined by p _ z states in graphene is shown to depend only slightly on the number of Co layers intercalated into the gap between the cobalt and graphene layers.
Динамический потенциал взаимодействия атомов азота с поверхностью кристалла алюминия
Authors: Малышевский В.С. , Фомин Г.В. , Дергачева Е.В. , Жилина Т.И.
Published: May 2018

AbstractSpecific features of the angular distributions of accelerated neutral nitrogen atoms at the grazing angles of incidence on the Al(001) crystal surface have been investigated by the computer simulation method. The N–Al pair interaction potential is approximated by the three-parameter Morse potential with the energydependent coefficients. The angular distributions of scattered atoms have been simulated taking into account the interaction between atoms and several atomic layers in the lattice and the atomic displacement during thermal oscillations. The parameters of the pair potential of accelerated neutral nitrogen atoms in the energy range from 10 to 70 keV have been determined according to the best agreement between the calculated dependence of the rainbow scattering angle on the energy of particles incident on the crystal surface and the available experimental data.
Механизмы поглощения терагерцового и инфракрасного излучения в пленках PZT
Authors: Командин Г.А. , Породинков О.Е. , Спектор И.Е. , Волков А.А. , Воротилов К.А. , Серегин Д.С. , Сигов А.С.
Published: May 2018

AbstractTerahertz and IR spectra of dielectric response of dense and porous Pb(Zr,Ti)O_3 films deposited on single-crystal magnesia and alumina substrates and on silicon substrates with a conducting platinum sublayer are measured in the and analyzed. We consider the key mechanisms of electric dipole absorption that give rise to absorption bands observed in experimentally measured reflection and transmission spectra, and discuss the relationship between the type of substrate and the parameters characterizing the absorption bands in the spectra of the prepared PZT films.
Электро- и магнетотранспорт в области межфазной границы LaAlO-=SUB=-3-=/SUB=-/SrTiO-=SUB=-3-=/SUB=-
Authors: Бойков Ю.А. , Данилов В.А. , Серенков И.Т. , Сахаров В.И. , Волков М.П.
Published: May 2018

AbstractComparison of the channel spectra of medium energy ion scattering, visualized for LaAlO_3/(001)SrTiO_3 heterostructures with a thickness of the lanthanum aluminate layer of one to six unit cells, indicates that the lanthanum aluminate layer grows coherently on a TiO_2-terminated surface of a strontium titanate substrate. The resistance of the interphase boundary in the heterostructure with a thickness of the LaAlO_3 layer of six unit cells decreased with temperature. At T < 100 K, the positive magnetoresistance and Hall mobility of electrons increased sharply with decreasing temperature.
Механизм пластического коллапса наноразмерных кристаллов с ОЦК-решеткой при одноосном сжатии
Authors: Малыгин Г.А.
Published: May 2018

AbstractWithin the dislocation–kinetic approach, based on the nonlinear kinetic equation for dislocation density, an attempt is made to consider the problem of a catastrophic plastic collapse of defect-free nanocrystals of metals with bcc lattice under their uniaxial compression with a constant deformation rate. Solutions of this equation were found in the form of moving waves, describing the dislocation multiplication process as the wave moves along the crystal from a local dislocation source. Comparison of the theory with the results of experiments on defect-free Mo nanocrystals showed that their ultrahigh strength at the initial stage of deformation is associated with a low rate of rise of crystal plastic deformation in comparison with the growth of its elastic component. The subsequent plastic collapse of crystal is caused by a sharp increasing the plastic component, ending with reaching the equality of elastic and plastic deformation rates.
Эффективная скорость движения доменной границы в квазиодномерной наносистеме при множественном рождении доменов новой фазы
Authors: Петухов Б.В.
Published: May 2018

AbstractThe process of switching a metastable state into an energetically preferable state in extended quasione- dimensional systems often occurs through the motion of domains walls of new phase. Usually considered limit cases are the propagation of the edge domains over the whole system or multiple nucleation and coalescence of domains in the volume of the material. This paper deals with the more general situation of front propagation of the switching state from the sample edge at a multiple nucleation of domains of a new phase on randomly located defects in the volume. The corresponding statistically-kinetic problem is solved with the calculation of the average magnitude and dispersion of path lengths, as well as the full generating function for finding higher moments of distribution of “the relay” run lengths of the boundary of the edge domain.
Неустойчивость течения в сферическом слое при вращательных колебаниях внутренней границы
Authors: Жиленко Д.Ю. , Кривоносова О.Э.
Published: May 2018

AbstractThe instability of viscous incompressible fluid flows caused in a thin spherical layer by torsional oscillations of the inner sphere in a thin spherical layer with respect to the sate of rest is studied numerically. It has been established that an increase in the frequency of torsional oscillations leads to a change in the mode of the instability, with a transition from secondary flows in the form of Taylor vortices to structures not observed earlier. The revealed instability is observed in the frequency range from 0.61 to 2.45 Hz or, if the wavelengths are taken relative to the layer thickness, from 0.67 to 1.33.
Невероятный эффект скорости подъема тепловой нагрузки на удельный тепловой поток при кипении некоторых наножидкостей
Authors: Бондаренко Б.И. , Морару В.Н. , Сидоренко С.В. , Комыш Д.В. , Гудков Н.Н.
Published: May 2018

AbstractBoiling curves for different heat-load increase rates (HLIRs) are obtained for distilled water, tap water, and two nanofluids (NFs) based on a natural mixture of montmorillonite and attapulgite (AlSi-7) and titanium dioxide (NF-8). An unusually strong influence of the HLIR on the thermal parameters of NFs is detected upon boiling of AlSi-7 based on a mixture of highly anisometric nanoparticles of aluminosilicates of various morphologies capable of forming nanostructured openwork “architectures” on the heater surface. An explanation of the reasons for the observed effect is proposed. The data obtained indicate the existence of an optimal HLIR at which the structure of the deposit appearing on the heating surface during the boiling of an NF is most favorable for heat exchange.
Структура, диэлектрические и оптические свойства c-ориентированных пленок SBN-50, выращенных на подложке Pt/Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-
Authors: Павленко А.В. , Ковтун А.П. , Зинченко С.П. , Стрюков Д.В.
Published: May 2018

AbstractStudies of the structure, dielectric and optical properties of thin films of a relaxor ferroelectric Ba_0.5Sr_0.5Nb_2O_6 grown on Pt(111)/Al_2O_3 (c-cut) substrate by high-frequency RF-sputtering in oxygen atmosphere, were performed. X-ray diffraction studies showed that Ba_0.5Sr_0.5Nb_2O_6 films are c-oriented. The unit cell parameters in the tetragonal approximation were c = 3.949(1) Å and a = 12.38(1) Å. It was established that the ferroelectric–paraelectric phase-transition temperature rises and optical anisotropy increases in the object in comparison with the bulk material. Reasons for the elucidated regularities are discussed.
Механизм генерации синглетного кислорода в присутствии возбужденного нанопористого кремния
Authors: Самосват Д.М. , Чикалова-Лузина О.П. , Хромов В.С. , Зегря А.Г. , Зегря Г.Г.
Published: May 2018

AbstractA theoretical analysis of the mechanism of generation of singlet oxygen in the presence of photoexcited nanoporous silicon is presented. It is demonstrated that the mechanism of generation of singlet oxygen is based on nonradiative energy transfer from nanoporous silicon to an oxygen molecule by the exchange mechanism. An analytical expression of the probability of energy transfer from nanoporous silicon to an oxygen molecule is obtained, and a numerical estimate of this process is given. The numerical estimation is of the order of 10^3–10^4 s^–1, a value that agrees rather well with the experiment.
Получение пористого вольфрама из пленочных покрытий системы вольфрам-кадмий
Authors: Тулеушев Ю.Ж. , Володин В.Н. , Жаканбаев Е.А. , Сукуров Б.М. , Козловский А.Л.
Published: May 2018

AbstractSolid solutions (alloys) with a Cd concentration of 50.3–76.3 at % were synthesized for the first time in the form of coatings by ion–plasma sputtering and codeposition of ultrafine W and Cd particles. When coatings were formed by tungsten and cadmium nanolayers, the components dissolved mutually to produce solid solutions of one metal in the other. A solid solution of cadmium in tungsten was synthesized at Cd concentrations up to 60.9 at %. At a cadmium concentration of 68.6 at % in the coating, the crystalline structure of cadmium with an admixture of amorphous tungsten was produced. At 800°C, tungsten evaporated from tungsten–cadmium coatings to form porous tungsten. The results of examination of materials fabricated on the basis of porous tungsten are planned to be used in practice.
Гальваномагнитные свойства тонких пленок Bi-=SUB=-95-=/SUB=-Sb-=SUB=-5-=/SUB=- на подложках с различным температурным расширением
Authors: Грабов В.М. , Комаров В.А. , Демидов Е.В. , Суслов А.В. , Суслов М.В.
Published: May 2018

AbstractResults of an investigation of galvanomagnetic properties of Bi_95Sb_5 block thin films on substrates with different coefficients of thermal expansion covered with polyimide are presented. The difference between thermal expansions of the film material and the substrate was found to have a strong effect on the films’ galvanomagnetic properties. Analysis of the properties of the films using the two-band model showed that the concentration and mobility of the charge carriers in the Bi_95Sb_5 films are related to the coefficient of thermal expansion of the substrate material.
Решение электродинамической задачи для микрополосковой излучающей структуры с киральной подложкой
Authors: Бузова М.А. , Клюев Д.С. , Минкин М.А. , Нещерет А.М. , Соколова Ю.В.
Published: May 2018

AbstractWe present a solution of the electrodynamic problem for a microstrip radiating structure with a substrate of a chiral metamaterial using the singular integral representation of the field, which in turn is reduced to a singular integral equation with the Cauchy-type singularity relative to the longitudinal component of the surface current density. Graphs of the current distribution for different types of substrates and the chirality parameters of a substrate are given.
Электрические токи, индуцированные в плазме ионно-звуковыми солитонами: учет захваченных электронов
Authors: Трухачев Ф.М. , Томов А.В. , Могилевский М.М. , Чугунин Д.В.
Published: May 2018

AbstractThe currents induced by ion-acoustic solitons have been studied in a two-component magnetic–hydrodynamic approximation (MHD model) taking into account the trapped electrons. The solitons have been shown to excite unipolar nonpolar pulses of the ion and electron currents, and the established mechanisms of their excitation are. The spatiotemporal characteristics of the current pulses have been calculated, and the requirements for the spatiotemporal resolution of the experimental equipment necessary for detection of plasma currents induced by solitons have been determined. It has been shown that the solitons are the effective mechanism of plasma current generation.
Влияние постоянных магнитных полей на динамику расплавленных зон в поле структурной неоднородности кремния
Authors: Скворцов А.А. , Пшонкин Д.Е. , Корячко М.В. , Рыбакова М.Р.
Published: May 2018

AbstractThe effect of constant magnetic fields on the formation and dynamics of molten Al–Si inclusions in silicon in the field of structural inhomogeneity of a crystal (the dislocation density-gradient field) is considered. The migration rates of liquid inclusions in crystals have been found experimentally under conditions of prevailing melting–crystallization mechanisms at the phase interfaces between the melt and matrix before and after magnetic exposure. It has been found that a preliminarily exposure of dislocation silicon samples in a constant magnetic field leads to an increase in the displacement speed of molten zones in the density-gradient field.
Кинетическая модель формирования кристаллов белка в капиллярах методом контрдиффузии
Authors: Соколовский А.С. , Лубов М.Н. , Беседина Н.А. , Трушин Ю.В. , Дубина М.В.
Published: May 2018

AbstractA kinetic model of crystallization of lysozyme is proposed, and computer calculations of this process are carried out. The conditions for the formation of such crystals are determined. Under these conditions, individual crystals were grown that were suitable for X-ray examination. The developed model enables prediction of the quantity, size, and place of crystal nucleation inside the capillary.
Режимы с интенсификацией теплообмена при испарении в тонких горизонтальных слоях жидкости при пониженных давлениях
Authors: Жуков В.И. , Павленко А.Н.
Published: May 2018

AbstractThe influence of structures formed during the evaporation and boiling of a liquid (n-dodecane) in thin horizontal layers on heat transfer has been analyzed. Structures shaped with the shapes of funnels and craters are formed at low pressures in liquid layers with thicknesses above the capillary constant under the action of a vapor recoil force. Increasing pressure leads to the onset of bubble boiling. It is established that the formation of these structures in the regime of intense evaporation at low reduced pressures leads to an about 70% increase in the heat-transfer coefficient at analogous layer thicknesses in comparison to the case of bubble boiling.
Влияние бора на структуру и проводимость тонких пленок, получаемых лазерной абляцией алмаза при 700-=SUP=-o-=/SUP=-C
Authors: Романов Р.И. , Фоминский В.Ю. , Зинин П.В. , Троян И.А. , Фоминский Д.В. , Джумаев П.С. , Филоненко В.П.
Published: May 2018

AbstractStructural features of CB_ x films obtained by pulsed laser ablation of targets made of pressed diamond powder with boron-powder additions at B/C atomic ratio of x = 0.33 have been studied. The films were deposited on heated substrates, so that diffusion processes involving C and B atoms on the surface and in the volume of films were possible. Selected conditions of film deposition ensured their effective doping with boron (0.4 ≤ x ≤ 0.6). The incorporation of B atoms was accompanied by the formation of B–C chemical bonds, whereas the formation of sp ^2 graphite bonds and their ordering in clusters with laminar packing was suppressed. The films possessed very low resistivity (~1.4 mΩ cm) at room temperature and exhibited metallic type of conductance on decreasing the temperature to 77 K.
Формирование полых свинцовых структур на поверхности пленок PbSe при обработке в аргоновой плазме
Authors: Зимин С.П. , Амиров И.И. , Наумов В.В. , Гусева К.Е.
Published: May 2018

AbstractConditions for ion sputtering of a PbSe/CaF_2/Si(111) epitaxial system in high-density inductively coupled plasma of high-frequency low-pressure discharge in argon have been established that ensure the formation of submicron-sized hollow lead structures on a lead-selenide surface. The surface was plasma-treated for time periods within 60–240 s at low energy (20–30 eV) of Ar^+ ions, which is close to their sputtering threshold energy. The properties of the obtained material were studied by the techniques of scanning electron microscopy and energy-dispersive X-ray microanalysis. It is shown that the characteristic size, shape, and density of surface structures can be varied within broad limits depending on the time of plasma treatment and temperature of the material surface. Physical processes responsible for the formation of hollow lead structures under the proposed conditions of plasma sputtering are considered.
Графен как сенсибилизирующая добавка в энергонасыщенную соль кобальта для усиления воздействия сильноточного электронного пучка
Authors: Савенков Г.Г. , Морозов В.А. , Илюшин М.А. , Кац В.М.
Published: May 2018

AbstractWe have studied the influence of graphene additives on the initiation of high-energy cobalt salt by a high-current electron beam of nanosecond duration. The high-energy composite was prepared by ultrasonic mixing of 80 wt% cobalt amminate (NCP) and 20 wt % graphene. It is established that the use of graphene as a sensitizing additive in a high-energy composite decreases the necessary energy parameters of the initiating electron beam and increases the energy characteristics and combustion rate of high-energy materials.
Полуполярные GaN-слои на наноструктурированной Si(100)-подложке
Authors: Бессолов В.Н. , Коненкова Е.В. , Орлова Т.А. , Родин С.Н. , Щеглов М.П. , Кибалов Д.С. , Смирнов В.К.
Published: May 2018

AbstractWe propose a new method for growing semipolar GaN films on a Si(100) substrate with an array of sub-100-nm-sized V-grooves formed on the surface. It is shown that, using such a nanostructured substrate for metalorganic hydride vapor-phase epitaxy, it is possible to obtain GaN (101̅1̇) epilayers deviating by an angle of about 62° from the polar direction and having an X-ray rocking curve with a minimum FWHM value of ω_θ ~ 60 arcmin.
Синтез высокоориентированных пленок оксида цинка на аморфных подложках методом магнетронного распыления на постоянном токе
Authors: Исмаилов А.М. , Эмирасланова Л.Л. , Рабаданов М.Х. , Рабаданов М.Р. , Алиев И.Ш.
Published: May 2018

AbstractWe describe the technology of obtaining highly oriented zinc-oxide (ZnO) films on amorphous substrates at high growth rates (up to 7 nm/s) by means of direct-current magnetron sputtering. It is suggested to optimize the substrate position with respect to magnetron and consider the floating potential to which the substrate is charged in magnetron discharge plasma as one of the main technological parameters. Electrondiffraction study of the structural characteristics of the obtained ZnO films showed that increase in the substrate temperature was accompanied by transformation of the crystallite shape from platelike to columnar.
Получение пленки оксида железа на сапфировой подложке
Authors: Клунникова Ю.В. , Малюков С.П. , Саенко А.В. , Сарычев Д.А. , Китаев В.В.
Published: May 2018

AbstractIron-oxide films on sapphire substrates were obtained using laser radiation with 1064-nm wavelength and studied by methods of scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission Mössbauer spectroscopy. The obtained Fe_2O_3 films probably occur in a superparamagnetic state and may find application in gas sensors and various magnetic devices.
Фемтосекундная лазерная запись волноводных микроструктур в пленках Рb(Zr,Ti)О-=SUB=-3-=/SUB=- и их характеризация нелинейно-оптическим методом
Authors: Елшин А.С. , Мишина Е.Д.
Published: May 2018

AbstractFemtosecond laser writing of ferroelectric one-dimensional microstructures possessing waveguide and nonlinear optical properties in Pb(Zr,Ti)O_3 films is considered, and the passage of light beams via obtained waveguide structures is traced. The optimum speed and power density of the writing laser beam are within 50–500 μm/s and 1–1.5 MW/cm^2, respectively. A two-stage method of writing is proposed, which provides for improved nonlinear optical properties of obtained waveguide microstructures.
Ближний порядок, транспорт заряда в SiO-=SUB=-x-=/SUB=-: эксперимент и численное моделирование
Authors: Гриценко В.A. , Новиков Ю.Н. , Сhin A.
Published: May 2018

AbstractThe structure of nonstoichiometric silicon oxide (SiO_ x ) has been studied by the methods of highresolution X-ray photoelectron spectroscopy and fundamental optical-absorption spectroscopy. The conductivity of SiO_ x ( x = 1.4 and 1.6) films has been measured in a wide range of electric fields and temperatures. Experimental data are described in terms of the proposed SiO_ x structure model based on the concept of fluctuating chemical composition leading to nanoscale fluctuations in the electric potential. The maximum amplitude of potential fluctuations amounts to 2.6 eV for electrons and 3.8 eV for holes. In the framework of this model, the observed conductivity of SiO_ x is described by the Shklovskii–Efros theory of percolation in inhomogeneous media. The characteristic spatial scale of potential fluctuations in SiO_ x films is about 3 nm. The electron-percolation energy in SiO_1.4 and SiO_1.6 films is estimated to be 0.5 and 0.8 eV, respectively.
Trump and U.S. Immigration Policies. Lessons from the Eisenhower Administration
Authors: Nardini Alia K.
Published: May 2018

While U.S. immigration entry policies after 1953 became a hallmark of ideological openness, designating the United States as the unquestioned leader of a freer and more just world order, Donald Trump’s current immigration strategies isolate America, damage her economy, and fuel divisive feelings among citizens. This paper hopes to persuade the Republican Party not to revert to its pre-1953 restrictionist and nativist stance, thereby undoing the crucial work undertaken by the Eisenhower Administration. The author argues that a sound grasp of the debate that led to the approval of the Refugee Relief Act in 1953 can lead to better informed political decision-making, tracing a new phase of America’s active presence on the world stage, in line with the country’s national interest and Cold war tradition.
Chemistry Students’ Science Process Skills Acquisition: Influence of Gender and Class size
Authors: Jack Gladys U.
Published: May 2018

Science process skills are central to the acquisition of scientific knowledge which is useful in problem solving in our immediate environment. In Nigeria, most secondary school students’ performances in chemistry in the West Africa Senior School Certificate Examination (WASSCE) are generally low which could probably be attributed to lack or poor exposure to science process skills. The study therefore investigated the influence of gender, and class size on Chemistry students’ acquisition of science process skills. The design adopted for the study was descriptive survey design. The sample comprised of 720 students drawn through multi-stage random sampling from Adamawa and Taraba States in Nigeria. The research instrument was Science Process Skills Knowledge Test in Chemistry’ (SPSKTC). The study indicated that gender have negligible influence on students’ acquisition of science process skills; while large class size have great influence on students’ acquisition of science process skills. The study concluded that most students in Nigerian schools experience difficulty in the acquisition of science process skills. Based on the findings, it was recommended that there should be reduction of student-teacher ratio in schools and training of teachers on science process skills to enable teachers adopt methods that lead students to have the appropriate skills.
Discussion on How Project Owners Carry out the Construction Management
Authors: Rong Ziren
Published: May 2018

In this article the significance and tasks of project owners carrying out the construction management are mainly discussed. The preparation, progress, quality and cost of the construction management are summed up. The contents and measures of each management work are summarized. Through the analysis project owners can improve the quality of engineering and achieve expected results.
Analysis of Chinglish from the Perspective of Feminism
Authors: Su Mingjing
Published: May 2018

Xi Yan is one of the protagonists and plays a significant role in Chinglish. The paper applies feminism to analyze Xi Yan and to find out what it represents. As opposed to the traditional women, Xi Yan goes after physical pleasure and spiritual fulfillment and gains both spiritual and physical freedom. In contrast with Chinese men, she performs even better than men and wins a certain economic and social status. In terms of foreign men, she prevails in the relationship with Daniel, which is a symbol of the rise of women that portends the rise of China.
The findings demonstrate that: Xi Yan symbolizes the transformation of modern women from being suppressed to the pursuit of spiritual and physical liberation; she is on behalf of strong women who try to improve the situation of women, in pursuit of equality; and the change in the relative power of male and female reveals the variation tendency of the relative force of the East and the West.
GREEN BIOSYNTHESIS OF MAGNETIC IRON OXIDE NANOPARTICLES OF VITEX NEGUNDO AQUEOUS EXTRACT
Authors: Karnan P. , Anbarasu A. , Deepa N. , Usha R.
Published: May 2018

Objective: The green synthesis of magnetic iron oxide nanoparticles is a convenient, economical, rapid and eco-friendly method compared to physical and chemical synthesis methods.Methods: In the present study iron oxide nanoparticles synthesized by Vitex negundo leaves extract.Results: The formation of iron oxide nanoparticles was confirmed by the colour change and further characterized by UV-Visible Spectroscopy and XRD. The morphology and the size of nanoparticles were analyzed by SEM and HR-TEM analysis.Conclusion: On the basis of this research work, green synthesized iron oxide nanoparticles can be a good source for alternative therapy for human diseases.
CARICA PAPAYA MEDIATED GREEN SYNTHESIZED SILVER NANOPARTICLES
Authors: Anbarasu A. , Karnan P. , Deepa N. , Usha R.
Published: May 2018

Objective: The present study was designed to biosynthesize NPs from leaves to study the reducing Ag+ions and stabilizing the particles and confirm AgNP synthesis by using various spectroscopy and microscopic methods.Methods: Bio-inspired AgNPs were rapidly synthesized at room temperature using fresh aqueous leaf extract of Carica papaya. A green and low-cost synthesis was effective in the formation of stable crystalline NPs in the solution. Amine, alkene and alkyl halides groups present in the Carica papaya leaf extract functioned as reducing as well as a stabilizing agent to produce shape controlled AgNPs.Results: SPR confirmed the formation of AgNPs in UV-Visible spectra at 445.7 nm. The XRD result also showed the presence of elemental Ag+as a crystalline nature. Study the functional groups responsible for the bio reduction of Ag+. HE-TEM and FE-SEM with EDX image showed spherical crystalline AgNPs.Conclusion: Hence, the plant-based bio AgNPs could be used in biomedical applications.
A STUDY ON DRUG UTILIZATION PATTERN OF CEPHALOSPORINS IN GENERAL MEDICINE AND SURGICAL INPATIENT DEPARTMENT
Authors: V. Naveen , Siddiq Abubaker , G. Chandana
Published: May 2018

Objective: Cephalosporins are a commonly used group of antibiotics in hospitals and healthcare facilities around the world. In the developed countries through the use of older cephalosporins is declining, that of the newer generations has increased. The objective of this study was to assess Drug Utilization Pattern of Cephalosporins in General Medicine and Surgical Inpatient Departments of tertiary care hospital.Methods: The data of enrolled patients were collected from case records of admitted inpatients during the study period. The collected data was assessed by statistical analysis using descriptive analysis.Results: A total of 110 inpatients were enrolled in the study. Out of 110 patients, males were 54.5% and females were 45.5%. The results analyzed that the prescriptions are more with third-generation cephalosporins than fourth-generation cephalosporins.Conclusion: The study concludes that 3rd generation cephalosporins is widely used for treating various nosocomial infections.
A CASE CONTROL STUDY ON DETERMINANTS OF CHILDHOOD ASTHMA IN SCHOOL CHIL-DREN OF CHITRADURGA CITY
Authors: M. Prakruthi G. , R. Bharathi D. , R. Yogananda
Published: May 2018

Objective: Asthma is a chronic airway inflammatory disease in which many cells and cellular elements play a role often arising from allergies, subsequently cause shortness of breath, wheezing and coughing it affects children in different ways. To study the sociodemographic characteristics of asthmatic children and compare the predisposing factors of asthma in children.Methods: A Community based Case control study in selected schools in chitradurga for a period of 6 mo. A total of 90 children, among which 30 asthma children and 60 non asthma children were participated. Odds ratio will be calculated to know the strength of association. chi square test will be calculated to the significance.Results: A total of 90 children aged<14 y data. Female children are more exposed to asthma than male. In childhood asthma age group between 10-14years the age group of 10 y(26.7%) and 12 y (26.7%) were more exposed to the asthma.Conclusion: In Chitradurga city, the study area, is of no exception with regard to case control. From the total of 90 children selected for the study majority were found risk factors affected. It was due to their family history, exposure to pet animals, allergy, age group, BMI and sex.
ANTICONVULSANT EFFECTS OF NIMODIPINE ALONE AND COMBINATION WITH PHENYTOIN ON MES INDUCED SEIZURES
Authors: Raina Jain , Ashish Jain
Published: May 2018

Objective: To evaluate the anticonvulsant activity of Nimodipine alone and in combination with Phenytoin, in MES induced seizures.Methods: The study was conducted in mice and MES seizure was induced by Techno electro-convulsometer. In the first part of the study, animals were treated with Nimodipine (20 mg/kg i. p. and 40 mg/kg i. p.) and Phenytoin (0.5 mg/100g i. p. and 1.0 mg/100g i. p.), MES was induced and durations of various phases were noted. Duration of Tonic hindlimb extension (THLE) was taken as an index for antiepileptic activity. In the second part, the animals were treated with a combination of sub effective doses of Nimodipine (20 mg/kg i. p.) and Phenytoin (0.5 mg/100g i. p.), MES was induced and durations of various phases were noted.Results: Nimodipine produced significant antiepileptic activity, in a dose-dependent manner. Phenytoin produced a significant antiepileptic effect in dose of 1.0 mg/100g, but failed to produce any such effect in a dose of 0.5 mg/100g, when administered alone. But when sub-effective doses. Of Nimodipine and Phenytoin were combined, a synergistic effect was seen.Conclusion: Nimodipine posses significant antiepileptic activity, alone, as well as it potentiates the antiepileptic effect of Phenytoin, suggesting the novel application of already proven safe and efficacious calcium channel blockers.
EVALUATION OF IN VITRO ANTIUROLITHIATIC ACTIVITY OF CHLORIS BARBATA
Authors: M. Niharika , V. Harshitha , P. Ashwini , B. Srivinya , J. Himabindhu , K. Ramanjaneyulu
Published: May 2018

Objective: The present study was undertaken to evaluate the in vitro antiurolithiatic activity of the medicinal plant Chloris barbata.Methods: The crude plant extract was prepared by Soxhlet extraction method.Results: Both Ethanolic and Aqueous extracts showed their maximum efficiencies in the dissolution of calcium oxalate crystals. Ethanolic extract was even more efficient than Aqueous extract in the dissolution of calcium oxalate crystals. Our results have clearly indicated that the Aqueous and Ethanolic leaf extracts of Chlorisbarbata were quite promising for further studies in this regard. In this study, Neeri was used as standard drug.Conclusion: This study has given primary evidence for Chloris barbata as the plant which possess antiurolithiatic property.
Los Estudios de Salud Familiar
Authors: Quiroz Pérez José
Published: May 2018

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La mano orientación diagnóstica radiológica
Authors: Santín García Guillermo
Published: May 2018

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Identifique el caso a través de la imagen
Authors: Gómez Clavelina Francisco J. , Hamui Sutto Alicia
Published: May 2018

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Dos breves reflexiones sobre el presente y futuro de la medicina familiar en México
Authors: Irigoyen Coria A. , Ponce Rosas R.
Published: May 2018

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Influenza enfoque social de la labor médica
Authors: Quiroz Pérez Miguel Ángel
Published: May 2018

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Cómo escribir un artículo de clase mundial. Consejos prácticos que ayudarán a su publicación. Primera Parte
Authors: Eger Arthur J. MSC , Elsevier B. V.
Published: May 2018

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Modificaciones del hábito tabáquico en familias de niños asmáticos
Authors: Del Campo Sánchez Ana Luz , Gómez Clavelina Francisco Javier
Published: May 2018

Introducción: el tabaquismo en la familia influye directamente en la salud respiratoria de los hijos y los predispone a padecer asma infantil. Al hablar sobre el tabaquismo pasivo como factor de riesgo para desarrollar asma infantil, el médico familiar realiza acciones preventivas y de educación para la salud, tanto con el paciente como con la familia. Objetivos: evaluar las modificaciones en el hábito tabáquico que realiza la familia del paciente asmático, con base en la orientación específica que otorga el médico familiar, acerca del tabaquismo pasivo como factor de riesgo. Material y métodos: estudio observacional, descriptivo, transversal, prospectivo. Se aplicaron 100 cuestionarios mediante entrevista estructurada a los padres de familia o tutores de niños entre dos y 14 años, con diagnóstico de asma, expuestos a humo de tabaco en el hogar, atendidos por un médico familiar en un lapso no menor a seis meses. Los sujetos de estudio se captaron en el Centro de Salud José Castro Villagrana y en el Hospital Pediátrico de Coyoacán, en México, entre marzo de 2007 y marzo de 2008. Se recopiló información para identificar condiciones relacionadas con el tabaquismo y el asma bronquial. Resultados: se informó a la familia del paciente asmático sobre el riesgo del tabaquismo pasivo en 83% de los casos. La orientación del médico familiar modificó sus hábitos tabáquicos en 69.9% de los casos. Los cambios fueron: fumar fuera de casa (48.9%), disminuir el consumo de cigarrillos (31.5%), evitar fumar cerca del niño (10.5%) y dejar de fumar (9.2%). Los familiares que más modificaron sus hábitos fueron los padres de los niños con predominio de la madre (81.5%) comparado con el padre (80.3%). Cuando la modificación en los hábitos tabáquicos dependía de un solo integrante, se encontró que los tíos (77.7%) y los abuelos (66.6%) no modificaron sus hábitos. Conclusiones: el médico familiar identifica el tabaquismo en la familia como factor de riesgo para padecer asma y otorga orientación. La modificación del hábito tabáquico que realizó la familia, en la mayoría de los casos, fue fumar fuera de casa. Es importante que los profesionales de la salud apliquen diversas estrategias que propicien cambios en el habito tabáquico para beneficio tanto del niño asmático como de la familia del fumador.
Identifique el caso
Authors: Irigoyen Coria Arnulfo , Delgado Quiñones Edna G. , Magaña Sandoval Mónica A. , Robles Romero Miguel A. , Valdivia López Antonio
Published: May 2018

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