bluuebunny/crossref_metadata_2025 huggingface dataset:
No Difference Between Iron Supplementation Only and Iron Supplementation with Synbiotic Fermented Milk on Iron Status, Growth, and Gut Microbiota Profile in Elementary School Children with Iron Deficiency
Authors: Helmyati Siti , Rahayu Endang Sutriswati , Kandarina Bernadette Josephine Istiti , Juffrie Mohammad
Published: October 2018

Background:

Iron deficiency may inhibit the height increase and weight gain of children.
On the other hand, the supplementation of iron causes gut microbiota imbalance which leads to inflammation
and diarrhea. The addition of synbiotic fermented milk is expected to have beneficial effects
on iron supplementation. This study aimed to determine the effects of iron supplementation only
and its administration with synbiotic fermented milk on iron status, body height and weight, and
gut microbiota profile of iron deficient elementary school children.

Methods:

This research was an experimental study with pre and post test conducted on 59 irondeficient
children. Subjects were given iron supplementation in syrups (IS group) or given iron supplementation
in syrup with fermented milk (containing synbiotic Lactobacillus plantarum Dad 13
and fructo-oligosaccharide) (ISFM group) for 3 months. The body weight and height, hemoglobin
and serum ferritin levels, and total number of Lactobacilli, Enterobacteria, Bifidobacteria, and Escherichia
coli were measured at the beginning and the end of the study.

Results:

The body height in the ISFM group increased significantly than that in IS group after the intervention
(1.67 vs. 2.42, p<0.05). The hemoglobin and serum ferritin levels in IS and ISFM groups
were improved significantly (p<0.05) although the difference between the two groups was not significant
(p>0.05). The results showed no significant difference of gut microbiota profile between the IS
and ISFM groups (p>0.05).

Conclusion:

There is no difference on the iron status, height, weight, and gut microbiota profile of
iron-deficient primary school children received iron supplementation only or iron supplementation
with synbiotic fermented milk.
Chemical Properties, Qualitative Parameters and Antioxidant Activity of Virgin Oil Obtained from Olea europaea Linn cultivar Zard Cultivated in Three Different Regions of Iran (Roudbar, Shiraz and Dezful)
Authors: Tavakoli Javad , Hashemkhani Samaneh
Published: October 2018

Background:

Zard variety is a popular olive variety widely cultivated in different regions
of Iran. Despite the extensive cultivation of this olive cultivar, little research has been carried out on
its various properties. Thus, chemical properties, qualitative parameters and antioxidant activity of
Olea europaea Linn cultivar Zard oil cultivated in three different regions including Roudbar, Shiraz
and Dezful could be an interesting topic for research.

Methods:

After oil extraction of different olive samples, their different characteristics were
compared. For this purpose, fatty acid composition, unsaponifiable matters, antioxidant compounds,
qualitative parameters (acid value, peroxide value, carbonyl value, total polar compounds) Antioxidant
activity assay (DPPH radical-scavenging assay and ferric reducing-antioxidant power (FRAP))
and oxidative stability index were measured.

Results:

Palmitic acid, oleic acid and linoleic acid contents in Zard variety cultivated in Roudbar
(ZR), Zard variety cultivated in Shiraz (ZS) and Zard variety cultivated in Dezful (ZD) oils were
13.1, 15.2, 13.2; 72, 60.4, 68.8; 9.1, 17 and 12.2; respectively. The highest phenolic and tocopherol
content was observed in ZD oil (90.4, and 160.2 mg/kg), followed by ZR (73.3, and 121.2 mg/kg)
and ZS (52.2 and 67.5 mg/kg) oils. Evaluation of qualitative parameters in the oils revealed that they
have suitable quality. Antioxidant activity assay indicated that ZD oil had the highest antioxidant activity,
followed by ZR and ZS oils.

Conclusion:

Results of this investigation indicated that there was a direct relation between antioxidant
activity and antioxidant content. Also, climatic difference in cultivation regions was a reason of
significant difference in the properties of ZR, ZS and ZD oils.
A Rare Non-penetrant Abdominal Wall Injury Caused by High-pressure Water: A Case Report
Authors: Gokaslan Cigdem Ozer , Gokaslan Serkan , Toprak Ugur
Published: October 2018

Background:

High-pressure water jet injuries are an uncommon cause of trauma. Highpressure
water injuries are usually seen at the extremities and less often in the thorax and abdominal
areas. A review of the literature reveals a few case reports describing intraabdominal injuries
due to penetrating trauma. İn this paper, we present the radiological findings of a rare case of abdominal
wall injury without penetration of peritoneum caused by high-pressure water jet due to the
Coanda effect. The Coanda effect is the tendency of a fluid jet to stay attached to a curved.

:

In our case, the peritoneum also functions as flat and curved surface, causing non-penetrant abdominal
wall injury.

Case Report:

A 28-year-old male working at a hydroelectric terminal presented to the emergency
department with abdominal pain and a two-centimeter cutaneous gap in the left lower quadrant of
the abdomen caused by high-pressure water.

:

The CT findings revealed a small entrance to left lower quadrant of the abdominal wall and extensive
subcutaneous injury. There was no internal injury. The cutaneous gap was managed by primary
surgical closure. Subcutaneous emphysema was diminished on the follow up physical examination.
The patient was recovered without sequelae.

Conclusion:

The water jet can cause a wide subcutaneous injury by following the peritoneum even
though there is a small entrance. Therefore radiological imaging can help to determine their severity
and planning treatment.
Biological Activities of Flavonoids from the Wood Extract of Artocarpus heterophyllus L. (Jackfruit)
Authors: Akazawa Hiroyuki , Shinozaki Takuro , Ukiya Motohiko , Akihisa Toshihiro , Jiradej Manosroi , Tokuda Harukuni , Fukatsu Makoto
Published: October 2018

Background:

Artocarpus heterophyllus L. (Jackfruit) has been used traditionally as
treatment for inflammation and cancer. The aim of this study was to isolate compounds from A. heterophyllus
wood extract and evaluate their biological activities such as anti-tumor promoting effect
on Epstein-Barr virus early antigen induction, melanogenesis inhibitory activity on the B16 mouse
melanoma 4A5 cell line and cytotoxic activity against three human cancer cell lines (HL60, A549,
SK-BR-3).

Methods:

A. heterophyllus wood was extracted with n-hexane and methanol. The ethyl acetate soluble-
fraction separated from the methanol extract was separated and purified with column chromatography
to isolate compounds. The structures of isolated compounds were elucidated with spectroscopic
methods. These compounds were evaluated for their biological activities.

Results:

Thirteen known compounds including four prenylflavonoids were isolated from the wood
extracts. Nine flavonoids (2, 3, 5-11) exhibited potent anti-tumor promoting activity with IC50 values
of 259-296 molar ratio / 32 pmol TPA. Two flavonoids, Norartocarpetin (6) at concentration of 30
μM and cyanomaclurin (11) at the concentration of 100 μM showed melanin content value of 47.6
% and 80.1 %, respectively. Two prenylflavonoids, cudraflavone B (2) and artocarpin (5), showed
cytotoxicity against the human cancer cell lines tested. Cudraflavone B (2) showed cytotoxicity
against all three human cancer cell lines whereas artocarpin (5) only exhibited cytotoxicity against
two out three cell lines testes. The IC50 values were comparable to or better than cisplatin.

Conclusion:

From the view point of structure activity relationships of the flavonoids isolated, side
chains such as prenyl and 3-methyl-1-butenyl moiety were key for their potent biological activities.
Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite
Authors: bin Zahari Muhammad Hanif , Guan Beh Hoe , Chuan Lee Kean , bin Zainudin Afiq Azri
Published: October 2018

Background:

Rare earth materials are known for its salient electrical insulation properties
with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel
ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of
Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4
(x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated.

Methods:

A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where
x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural,
morphological and magnetic properties of the samples were examined through X-Ray Diffraction
(XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer
(VSM) measurements.

Results:

XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The
average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited
agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared
to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as
evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+
concentration increases.

Conclusion:

The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform
microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted
samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization
can be explained based on weak super exchange interaction between A and B sites. The difference
in magnetic properties between the samples despite the slight difference in Sm3+ concentrations
suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need,
through the substitution of Fe3+ with rare earth ions.
Smart Approach of Solid Waste Management for Recycling of Polymers: A Review
Authors: Fatima Zernab , Roohi
Published: October 2018

Background: :

The world’s annual utilization of plastic materials is growing day by day and
simultaneously solid waste management is becoming one of the major environmental concerns
throughout the world. Current approach for their usage and disposal is not sustainable because of the
durability of the polymers involved.

Methods: :

Partially digested products of these plastics in the form of micro-plastics are accumulating
as debris in landfills and in natural habitats because of their remaining in the environment for millions
of years. Easy availability, low cost and ubiquitous applications make the plastics most attractive
polymer whose proper disposal through specific technology seems the only alternate and that may
lessen down the pollution over the next decades.

Results: :

Recycling as a waste management strategy provides opportunities to reduce the use of petrochemical
resources and improving environmental conditions. Reuse of bulky plastic wastes in concrete
and Wood Plastic Composites (WPC) seems a smart approach for solving the problem of disposal.
The development of new construction materials using recycled plastics is important to both the
construction and the plastic recycling industries.

Conclusion::

This review article presents the details of recycling of waste management, their probable
application for concrete and WPC production, types of recycled plastics, role of microbes and microbial
enzymes for recycling of plastics and emphasis on use of biodegradable plastics to make the environment
green.
A Dynamic Task Scheduling Algorithm for Cloud Computing Environment
Authors: Ben Alla Hicham , Ben Alla Said , Ezzati Abdellah
Published: October 2018

Background:

Cloud computing environment is a novel paradigm in which the services
are hosted, delivered and managed over the internet. Tasks scheduling problem in the cloud has become
a very interesting research area. However, the problem is more complex and challenging due
to the dynamic nature of cloud and users’ needs as well as cloud providers’ requirements including
the quality of service, users’ priorities and computing capabilities.

Objective:

The main objective is to solve the problem of tasks scheduling through an algorithm
which can not only improves the client satisfaction, but also allows cloud service provider to gain
maximum profit and ensure that the cloud resources are utilized efficiently.
Method: (a) Optimization of the waiting time and the queue length.

Methods:

(a) Optimization of the waiting time and the queue length.

(b) Distribution of all requests into a novel queueing system in a dynamic manner based on a decision
threshold.

(c) Assignment of requests to VMs based on Particle Swarm Optimization and Simulated Annealing
algorithms.

(d) Incorporation of the priority constraint in the scheduling process by considering three priorities
levels including the tasks, queues and VMs.

Results:

The results comparison of our algorithm with particle swarm optimization and First Come
First Serve algorithms demonstrate the effectiveness of our algorithm in terms of waiting time,
makespan, resources utilization and degree of imbalance.

Conclusion:

This study introduces an efficient strategy to schedule users’ tasks by using dynamic
dispatch queues and particle swarm optimization with simulated annealing algorithms. Moreover, it
incorporates the priority issue in the scheduling process.
Температурная зависимость порогового тока и выходной мощности квантово-каскадного лазера с частотой генерации 3.3 ТГц
Authors: Хабибуллин Р.А. , Щаврук Н.В. , Пономарев Д.С. , Ушаков Д.В. , Афоненко А.А. , Васильевский И.С. , Зайцев А.А , Данилов А.И. , Волков О.Ю. , Павловский В.В. , Маремьянин К.В. , Гавриленко В.И.
Published: October 2018

AbstractThe active region of a THz (terahertz) quantum-cascade laser based on three tunnel-coupled GaAs/Al_0.15Ga_0.85As quantum wells with a resonance-phonon depopulation scheme is designed. Energy levels, matrix elements of dipole transitions, and gain spectra are calculated as functions of the applied electric-field strength F and temperature. It is shown that the maximum gain is implemented at a frequency of 3.37 THz and F = 12.3 kV/cm. Based on the proposed design, a quantum-cascade laser emitting at ~3.3 THz with a double metal waveguide and T _max ~ 84 K is fabricated. The activation energy E _ a = 23 meV for longitudinal-optical (LO) phonon emission upon the stimulated recombination of hot electrons from the upper laser level to the lower one is determined from the Arrhenius temperature dependence of the output power.
Спинодальный распад в InSb/AlAs-гетероструктурах
Authors: Абрамкин Д.С. , Бакаров А.К. , Гутаковский А.К. , Шамирзаев Т.С.
Published: October 2018

AbstractThe atomic structure and energy spectrum of heterostructures formed in a system of InAs/AlAs binary compounds are studied. The In_ x Al_1 –_ x Sb_ y As_1 –_ y alloy, from which quantum wells are formed in InSb/AlAs structures, decomposes into two phases with different compositions. The characteristic dimensions of regions containing separate phases of the alloy in the structure plane are 5–7 nm. Spinodal decomposition of the alloy brings about the formation of coexisting indirect-gap regions with type-I and type-II energy spectra in quantum wells of the heterostructures.
Влияние состава газа-носителя в процессе роста дельта-слоя Mn на электрические и магнитные свойства GaAs-структур
Authors: Калентьева И.Л. , Вихрова О.В. , Данилов Ю.А. , Звонков Б.Н. , Кудрин А.В. , Антонов И.Н.
Published: October 2018

AbstractThe effect of the arsine content (from 0 to 8 μmol), supplied to a reactor together with hydrogen, on the formation of delta-doped gallium-arsenide structures by the pulsed laser sputtering of a Mn target is investigated. It is found that an arsine molar fraction of ~2.5 μmol in the reactor atmosphere during the formation of a Mn delta-doped GaAs layer allows one to obtain single-crystal epitaxial structures with the lowest layer resistance and a ferromagnetic-paramagnetic phase transition temperature of about 40 K. Increasing the arsine content to 8 μmol or the absence of arsine in a hydrogen flow leads to a significant increase in the layer resistance in the temperature range below 150 K and a decrease in the Curie temperature. In the first case, this may be due to partial compensation of the hole conductivity by donor-type defects formed as a result of an excess of arsenic on the growing surface (arsenic atoms in Ga positions or in interstitial positions). In the second case, when no arsine is supplied to the reactor, the growth surface is likely to be enriched with gallium atoms, which makes the incorporation of Mn into the Ga sublattice difficult.
Применение локально-неравновесной диффузионно-дрейфовой модели Каттанео-Вернотта для описания релаксации фототока в диодных структурах при воздействии субпикосекундных импульсов ионизирующих излучений
Authors: Пузанов А.С. , Оболенский С.В. , Козлов В.А.
Published: October 2018

AbstractThe excitation-relaxation process in electron–hole plasma upon exposure to ionizing radiation for a time shorter than the relaxation time of the mobile carrier energy and momentum is considered. By the example of the calculation of transient ionization processes in a silicon hyperhigh-frequency Schottky diode, local-equilibrium and local-nonequilibrium carrier transport models are compared. It is shown that the local-nonequilibrium model features a wider field of application for describing fast relaxation processes.
Исследование анизотропии структурных свойств слоев (0001)GaN, выращенных методом МОГФЭ на a-срезе сапфира (1120)
Authors: Юнин П.А. , Дроздов Ю.Н. , Хрыкин О.И. , Григорьев В.А.
Published: October 2018

AbstractThe structural properties of GaN(0001) heteroepitaxial layers grown by metalorganic vapor phase epitaxy (MOVPE) on a -plane (11 $$\bar {2}$$ 0) sapphire substrates are investigated by X-ray diffractometry. Anisotropy of the rocking-curve width for the symmetric (0004) and asymmetric {11 $$\bar {2}$$ 4} and {10 $$\bar {1}$$ 5} reflections of gallium nitride upon rotation of the sample is observed. A comparison of the anisotropy of the rocking-curve width for GaN(0001)/Al_2O_3(11 $$\bar {2}$$ 0) layers with two different variants of in-plane orientation relationships suggests that the anisotropy of the structural properties is independent of the thermoelastic stress arising upon cooling the heterostructure.
Модификация ферромагнитных свойств тонких пленок Si-=SUB=-1-x-=/SUB=-Mn-=SUB=-x-=/SUB=-, синтезируемых методом импульсного лазерного осаждения при изменении давления буферного газа
Authors: Новодворский О.А. , Михалевский В.А. , Гусев Д.С. , Лотин А.А. , Паршина Л.С. , Храмова О.Д. , Черебыло Е.А. , Дровосеков А.Б. , Рыльков В.В. , Николаев С.Н. , Черноглазов К.Ю. , Маслаков К.И.
Published: October 2018

AbstractA series of thin films of Si_1 –_ x Mn_ x alloys with a thickness from 50 to 100 nm grown by pulsed laser deposition on an Al_2O_3 substrate in vacuum and in an argon atmosphere is investigated. The significant effect of the buffer-gas pressure in the sputtering chamber on the structural and magnetic homogeneity of the obtained films is shown. The conditions for the formation of a ferromagnetic phase with a high Curie temperature (>300 K) in the samples are studied. With the use of the Langmuir probe method, the threshold of ablation of a MnSi target by second harmonic radiation (λ = 532 nm) of a Nd:YAG Q -switch laser is determined. The time-of-flight curves for the plume ions are obtained with a change in the energy density at the target and argon pressure in the sputtering chamber. A nonmonotonic dependence of the probe time-of-flight signal amplitude on the argon pressure is established for high-energy particles of the plume.
Синтез методом молекулярно-пучковой эпитаксии и структурные свойства GaP- и InP-нитевидных нанокристаллов на SiC-подложке с пленкой графена
Authors: Резник Р.Р. , Котляр К.П. , Илькив И.В. , Сошников И.П. , Лебедев С.П. , Лебедев А.А. , Кириленко Д.А. , Алексеев П.А. , Цырлин Г.Э.
Published: October 2018

AbstractThe possibility in principle of the MBE (molecular-beam epitaxy) growth of GaP and InP nanowires on a SiC substrate with a graphene layer is demonstrated for the first time. InP nanowires on such a substrate have no stacking faults and possess an ideal crystallographic quality. At the same time, GaP nanowires have structural defects of the type of twins and the reversal of crystallographic phases at the top and at the base. The results of structural measurements demonstrate that the nanowires are formed in the wurtzite phase, which is not typical of bulk III–V materials.
Исследование структурных и морфологических свойств HPHT алмазных подложек
Authors: Юнин П.А. , Волков П.В. , Дроздов Ю.Н. , Колядин А.В. , Королев С.А. , Радищев Д.Б. , Суровегина Е.А. , Шашкин В.И.
Published: October 2018

AbstractThe morphological and structural properties of a series of high-pressure high-temperature (HPHT) single-crystal diamond substrates are comprehensively studied by white-light optical interference microscopy, atomic-force microscopy, and X-ray diffraction analysis. Procedures that provide a means for characterizing the substrate parameters most critical for epitaxial application with the laboratory equipment are described. It is shown that the jewelry-type characterization of diamond substrates is insufficient to assess the possibility of their use for the epitaxial growth of chemical-vapor-deposited (CVD) diamond.
Спектроскопия одиночных AlInAs- и (111)InGaAs-квантовых точек
Authors: Деребезов И.А. , Гайслер В.А. , Гайслер А.В. , Дмитриев Д.В. , Торопов А.И. , von Helversen M. , de la Haye C. , Bounouar S. , Reitzenstein S.
Published: October 2018

AbstractA system of AlInAs- and InGaAs(111)-based quantum dots is studied. The use of wide-gap Al_ x In_1 –_ x As alloys as a basis for quantum dots provides a means for substantially extending the spectral region of emission to shorter wavelengths, including the region close to 770 nm which is of interest for the engineering of aerospace systems of quantum cryptography. The fine structure of exciton states in AlInAs and InGaAs(111) quantum dots is studied. It is shown that, for a set of quantum dots, the splitting of exciton states is comparable to the natural width of exciton lines, which is of interest for the engineering of emitters of photon pairs on the basis of these quantum dots.
Формирование и исследование локально-растянутых Ge-микроструктур для кремниевой фотоники
Authors: Новиков А.В. , Юрасов Д.В. , Морозова Е.Е. , Скороходов Е.В. , Вербус В.А. , Яблонский А.Н. , Байдакова Н.А. , Гусев Н.С. , Кудрявцев К.Е. , Нежданов А.В. , Машин А.И.
Published: October 2018

AbstractThe formation and properties of locally tensile strained Ge microstructures (“microbridges”) based on Ge layers grown on silicon substrates are investigated. The elastic-strain distribution in suspended Ge microbridges is analyzed theoretically. This analysis indicates that, in order to attain the maximum tensile strain within a microbridge, the accumulation of strain in all corners of the fabricated microstructure has to be minimized. Measurements of the local strain using Raman scattering show significant enhancement of the tensile strain from 0.2–0.25% in the initial Ge film to ~2.4% in the Ge microbridges. A considerable increase in the luminescence intensity and significant modification of its spectrum in the regions of maximum tensile strain in Ge microbridges and in their vicinity as compared to weakly strained regions of the initial Ge film is demonstrated by microphotoluminescence spectroscopy.
Радиационная стойкость терагерцовых диодов на основе GaAs/AlAs-сверхрешеток
Authors: Павельев Д.Г. , Васильев А.П. , Козлов В.A. , Оболенская Е.С.
Published: October 2018

AbstractThe radiation resistance to the gamma-neutron irradiation (~1 MeV) of diodes based on symmetric GaAs/AlAs 30-period superlattices is for the first time studied theoretically and experimentally. The model band diagram and equivalent circuit of the structure under study are used in calculations. Calculations are performed in the quasi-hydrodynamic approximation taking into account the heating of diodes under study by flowing current. The results of calculating the current–voltage characteristics and limiting operating frequencies of the diodes before and after gamma-neutron irradiation correlate well with the experimental data.
Снижение внутренних потерь и теплового сопротивления в лазерных диодах со связанными волноводами
Authors: Жуков А.Е. , Гордеев Н.Ю. , Шерняков Ю.М. , Паюсов А.С. , Серин А.А. , Кулагина М.М. , Минтаиров С.А. , Калюжный Н.А. , Максимов М.В.
Published: October 2018

AbstractThe results of studying edge-emitting quantum-well lasers with a layered design having coupled planar waveguides, capable of suppressing the generation of excited transverse modes, are presented. In this case, a low internal loss (0.4 cm^–1) is provided, combined with a small depth (~0.9 μm) of the active region, which results in a low thermal resistance of 6.0 (K/W) mm without a submount.
Подвижность и квантовое время бесщелевых дираковских электронов в квантовых ямах HgTe
Authors: Добрецова А.А. , Квон З.Д. , Брагинский Л.С. , Энтин М.В. , Михайлов Н.Н.
Published: October 2018

AbstractThe mobility and quantum time of Dirac electrons in HgTe quantum wells with near-critical thickness corresponding to the transition from the direct to inverted spectrum are experimentally and theoretically investigated. The nonmonotonic dependence of the mobility on the electron concentration is experimentally established. The theory of the scattering of Dirac electrons by impurities and irregularities of the well boundaries leading to well thickness fluctuations is constructed. The comparison of this theory with an experiment shows their good agreement and explains the observed nonmonotonic behavior by a decrease in the ratio between the de Broglie wavelength of Dirac electrons and the characteristic size of irregularities with increasing electron concentration. It is established that the transport time is larger than the quantum time by almost an order of magnitude in the case of the dominance of roughness scattering. The transition from macroscopic to mesoscopic samples is studied and an abrupt decrease in both the mobility and quantum time is observed. This behavior is attributed to the size effect on the free path length.
Разработка физико-топологической модели реакции мощного вертикального ДМОП транзистора на воздействие импульсного гамма-излучения
Authors: Хананова А.В. , Оболенский С.В.
Published: October 2018

AbstractA method for developing models of semiconductor devices with two-dimensional nonuniform concentration profiles of donors and acceptors in working regions of a semiconductor device structure is for the first time proposed based on a complex of physical-topological modeling of charge carrier transport and process simulation of the forming processes of the device structure. The application of process simulation is due to the need to correctly define the parameters of the semiconductor device structure, which are used as initial data to calculate the electron transport according to the physical-topological model. The parameters of production processes of ion implantation, diffusion, and lithography, which were refined during process simulation, are determined for a high-power metal—oxide—semiconductor (MOS) transistor forming by the double diffusion method in accordance with known electrical characteristics and measured geometrical sizes of the structure. This results in two-dimensional distribution profiles of donors and acceptors in p – n junctions necessary to calculate the transistor breakdown under the effect of pulsed γ radiation. Breakdown processes are modeled with the help of the physical-topological model based on the Poisson and continuity equations as well as expressions for the diffusion and drift current densities in the transistor. Accounting for carriers formed at the instant of γ irradiation is implemented by the introduction of the dependence of the generation coefficient of electron–hole pairs on the radiation-dose power. The results of calculations correlate well with the experimental data, which makes it possible to give a conclusion regarding the adequacy of the proposed complex model.
Проверка гипотезы о термоупругом характере деформации слоя (0001)GaN, выращенного на a-срезе сапфира
Authors: Дроздов Ю.Н. , Хрыкин О.И. , Юнин П.А.
Published: October 2018

AbstractThe deformation of a (0001)GaN epitaxial layer on the (11 $$\bar {2}$$ 0) sapphire a -cut is studied by X-ray diffractometry. Anisotropic-layer deformation is calculated by reference data on the thermal expansion coefficients of gallium nitride and sapphire. A comparison of the calculated and experimental deformation confirms the hypothesis on the thermoelastic character of GaN deformation on the sapphire a -cut. This result makes it possible, in particular, to assess theoretically the elastic deformation and piezoelectric field in pseudomorphic heterostructures with GaN layers on the sapphire a -cut as a virtual substrate or a buffer layer.
Многофононная внутрицентровая релаксация состояний акцепторов бора в алмазе
Authors: Бекин Н.А.
Published: October 2018

AbstractThe relaxation rates are calculated in the adiabatic approximation, in which the steady-state impurity states are taken to be electronic-vibrational (vibronic) states. The probabilities of transitions between these states with the emission (or absorption) of one or several phonons are calculated in first-order perturbation theory on the assumption that the transitions are a result of the violation of adiabaticity. The electron part of the wave function of the vibronic state is described by a simple Hamiltonian with an isotropic effective mass. The wave function of the ground state is determined by the quantum defect method. According to the calculations, a hole relaxes from the excited boron acceptor state, whose energy is 304 meV higher than the energy of the ground state, to the ground state with the emission of two optical phonons with a rate of ~10^11 s^–1. This value is an estimate from above, since the model of nondispersive optical phonons used in the study overestimates the number of phonon modes, whose participation in relaxation is allowed by the energy conservation law. However, despite the rough approximation, it can be concluded that the multiphonon relaxation of boron acceptor states in diamond is a fast process.
Импульсное возбуждение в двухкубитных системах
Authors: Гринберг Я.С. , Штыгашев А.А.
Published: October 2018

AbstractThe temporal dynamics of absorption of a single-photon pulse by two qubits interacting with a microwave field of a one-dimensional waveguide have been studied. The theory, which allows one to use arbitrary shapes of the input single-photon wave packet as an initial condition, as well as investigate the excitation dynamics of each qubit, has been developed. The numerical calculation is performed for the packet of a Gaussian shape, at different parameters of frequency detuning and duration of the input pulse. The excitation dynamics of both identical and nonidentical qubits have been studied. It has been specifically shown that it is possible to form symmetric and antisymmetric entangled states for identical qubits.
Структура и магнитные свойства нанопроволок из маталлов группы железа, полученных методом матричного синтеза
Authors: Загорский Д.Л. , Фролов К.В. , Бедин С.А. , Перунов И.В. , Чуев М.А. , Ломов А.А. , Долуденко И.М.
Published: October 2018

Abstract —Samples of arrays of nanowires are produced from iron, iron–cobalt and iron–nickel alloys via matrix synthesis based on polymer track membranes with pore diameters ranging from 30 to 300 nm. The influence of stress and pore diameter on the galvanic process and structure of nanowires is studied. The arrays of nanowires are examined by microscopy and X-ray diffraction. The magnetic properties are inspected via magnetometry and Mössbauer spectroscopy. The angular dependences of hysteresis loop shape are obtained and comprehensively discussed. As shown, decreasing the growth stress and/or increasing the pore diameter make the Mössbauer spectra of nanowires similar to those of bulk materials. Furthermore, the higher the growth stress is, the larger is the coercive force of nanowires. For the studied species of nanomaterials, the ability to control the magnetic properties during the synthesis is shown, as well.
Автогенерация хаотического СВЧ-сигнала в спин-волновом оптоэлектронном генераторе
Authors: Устинов А.Б. , Кондрашов А.В. , Никитин А.А. , Дроздовский А.В. , Калиникос Б.А.
Published: October 2018

Abstract —The self-generation of a chaotic microwave signal in a spin-wave optoelectronic generator has been experimentally investigated for the first time. The generator was a ring circuit, in the microwave path of which there was a spin-wave delay line on the film of an yttrium iron garnet (YIG) and a microwave amplifier. The optical path contained a fiber optic delay line. The nonlinear element of the generator was a film of YIG, which worked under the conditions of four-wave parametric interaction of spin waves. It has been shown that it is possible to generate monochromatic, periodic, quasi-periodic, and chaotic microwave signals by controlling the gain coefficient of the ring. The parameters characterizing the chaotic signal that are generated by the ring have been determined.
Влияние локальных корреляций на переход "однородный изолятор-сверхпроводник" в доменных границах фазы зарядового порядка 2D-системы со смешанной валентностью
Authors: Конев В.В. , Улитко В.А. , Ясинская Д.Н. , Панов Ю.Д. , Москвин А.С.
Published: October 2018

Abstract —It is demonstrated in the (pseudo)spin S = 1 formalism that the structure of antiphase domain boundaries in the phase of charge ordering of a mixed-valence system of the Cu^1+, 2+, 3+ “triplet” type in cuprates on a two-dimensional square lattice depends to a considerable extent on on-site correlation parameter U . The results of computer modeling on large square lattices illustrate the change in the boundary structure (from a homogeneous monovalent nonconducting structure of the Cu^2+ type to a filamentary superconducting one) induced by a relatively small variation of positive U values.
Исследование изолирующей области планарных сверхпроводниковых YBCO-структур, формируемых методом задающей маски
Authors: Мастеров Д.В. , Павлов С.А. , Парафин A.Е. , Скороходов Е.В. , Юнин П.А.
Published: October 2018

Abstract —The development of a new “master mask” method for the manufacture of planar structures based on a high-temperature YBCO superconductor is considered. The method involves the creation of a mask on the blank substrate and, upon deposition of YBCO, the superconducting elements are formed in preset local windows of the mask with isolation regions formed between them. Such growth conditions allow the fabrication of micron-size superconducting elements with excellent electrophysical parameters and a smooth su-rface. The influence of the parameters of the master mask of amorphous cerium oxide on the isolating properties of the resulting isolation regions during the fabrication of planar structures on sapphire and cubic zirconia substrates with epitaxial cerium oxide sublayers has been studied.
Флуктуационное образование фазовых солитонов в двузонных сверхпроводящих мостиках
Authors: Марычев П.М.
Published: October 2018

Abstract —Based on the Ginzburg–Landau theory, the dependence of the threshold energy δ F _thr of formation of a phase slip center from the current for a superconducting two-band bridge has been calculated. It has been found that, in the case of sufficiently long bridges and a weak interband Josephson coupling, there is a range of currents at which fluctuation transition from the state of the zero interband phase difference to the states with a phase soliton is possible, which manifests itself in a considerable decrease in the threshold energy δ F _thr, and a fluctuation change in the number of phase solitons in the bridge. In the case of a strong interband coupling, no fluctuation formation of phase solitons occurs and the dependence δ F _thr( I ) tends to the expression obtained earlier by Langer and Ambegaokar for a single-band superconductor.
Анизотропия эффекта Холла в квазидвумерном электронно-легированном сверхпроводнике Nd-=SUB=-2-x-=/SUB=-Ce-=SUB=-x-=/SUB=-CuO-=SUB=-4+delta-=/SUB=-
Authors: Клепикова А.С. , Чарикова Т.Б. , Шелушинина Н.Г. , Петухов Д.С. , Иванов А.А.
Published: October 2018

Abstract —The temperature dependences of the Hall effect of an electron-doped Nd_2 – _ x Ce_ x CuO_4 + δ superconductor have been studied at the antiferromagnet–superconductor quantum phase transition boundary (0.135 ≤ x ≤ 0.15) in conducting CuO_2 planes and in the direction perpendicular to the CuO_2 plane. The hall coefficient between the conducting planes has been found be two orders higher than that in the conducting planes over entire temperature range, which is due to the incoherent character of the charge carrier transfer in the direction of axis c .
Сверхпроводниковые гетероструктуры с прослойкой из материала с сильным спин-орбитальным взаимодействием
Authors: Овсянников Г.А. , Гришин А.С. , Константинян К.И. , Шадрин А.В. , Петржик А.М. , Кислинский Ю.В. , Cristiani G. , Logvenov G.
Published: October 2018

Abstract —Superconducting heterostructures interlayered with a material with strong spin–orbit interaction are studied. As materials with strong spin–orbit interaction, we choose strontium iridates featuring the Ruddlesden–Popper structure (Sr_ n  _+ 1Ir_ n O_3 n  _+ 1; n = 1, 2, ∞): paramagnetic metal SrIrO_3 and magnetic insulator Sr_2IrO_4. Using laser ablation, epitaxial films of these materials are obtained, as well as heterostructures based on epitaxial films of cuprate superconducting YBa_2Cu_3O_ x . For electrical measurements, mesa-structures of micrometer sizes with top electrodes made of Au/Nb bilayer are fabricated.
Линзовая щелевая антенна на основе тонких пленок Nb для джозефсоновского широкополосного генератора ТГц-диапазона
Authors: Кинев Н.В. , Рудаков К.И. , Барышев А.М. , Кошелец В.П.
Published: October 2018

Abstract —An oscillator based on the distributed tunnel superconductor-insulator-superconductor junction with an ultrawide operating bandwidth of up to 100% of the central frequency seems to be a promising type of directional source of continuous electromagnetic radiation in the terahertz frequency range. In this paper, we propose a scheme of a terahertz oscillator integrated on a single microchip with a transmitting lens antenna with the slot structure in a 200-nm Nb film to radiate the signal into the open space. We also proposed and numerically simulated several designs of a planar slot antenna matched (in the input) with a Josephson oscillator and (in the output) with a silicon elliptical lens. The obtained results of the matching of the oscillator output power with the antenna of various designs operating in four frequency ranges: 250–410, 330–570, 380–520, and 420–700 GHz are presented. The antenna beam patterns and impedances are calculated as well.
Исследование особенностей формирования и свойств полупроводников А-=SUP=-3-=/SUP=-В-=SUP=-5-=/SUP=-, сильно легированных железом
Authors: Данилов Ю.А. , Кудрин А.В. , Лесников В.П. , Вихрова О.В. , Крюков Р.Н. , Антонов И.Н. , Толкачев Д.С. , Алафердов А.В. , Кунькова З.Э. , Темирязева М.П. , Темирязев А.Г.
Published: October 2018

Abstract —Layers of InAs, InSb, and GaSb semiconductors highly doped with iron during their growth by the method of pulsed laser deposition are studied experimentally. The best temperatures for layer formation on GaAs (100) substrates are: 250°C (InSb : Fe), 300°C (InAs : Fe), and 350°C (GaSb : Fe). At high Fe concentration (over 10 at %) the layers display ferromagnetic properties expressed in emergence of a hysteresis curve within the magnetic field dependences of the Hall resistance, negative magnetoresistance, and in some cases, ferromagnetic-type magnetization at measurements at room temperature. The atoms of iron do not change the type of layer conductivity; InAs : Fe and InSb : Fe layers possess n -type conductivity, and GaSb : Fe layers display p -type conductivity due to their intrinsic point defects.
Повышение рабочей температуры спиновых светоизлучающих диодов (Ga,Mn)As/GaAs путeм постростовых воздействий
Authors: Малышева Е.И. , Дорохин М.В. , Данилов Ю.А. , Парафин А.Е. , Ведь М.В. , Кудрин А.В. , Здоровейщев А.В.
Published: October 2018

Abstract —Spin light emitting diodes (spin-LEDs) containing (Ga,Mn)As ferromagnetic layers are fabricated based on InGaAs/GaAs heterostructures and studied. We achieve increases in the operating temperatures of our spin-LEDs by subjecting the surface of the structures, prior to depositing an ohmic metal contact, to pulsed laser annealing. The fabricated devices produce circularly polarized electroluminescence when placed in an external magnetic field. The temperatures at which circularly polarized electroluminescence is still observed is raised from 30 K for unprocessed structure to 110 K for laser-annealed structures. The observed effect is linked to an increase in the Curie temperature of the (Ga,Mn)As layer as a result of laser impact.
Влияние плотности энергии лазерного пучка на магнитные свойства тонких пленок Mn-=SUB=-x-=/SUB=-Si-=SUB=-1-x-=/SUB=- (x~0.5), приготовленных методом импульсного лазерного осаждения
Authors: Дровосеков А.Б. , Савицкий А.О. , Крейнес Н.М. , Рыльков В.В. , Николаев С.Н. , Черноглазов К.Ю. , Талденков А.Н. , Черебыло Е.А. , Михалевский В.А. , Новодворский О.А. , Маслаков К.И. , Pandey P. , Zhou S.
Published: October 2018

Abstract —The effect of laser pulse energy E on the possibility of forming of a homogeneous “high-temperature” ferromagnetic phase in Mn_ x Si_1 – _ x ( x ≈ 0.5) alloy films grown by pulsed laser deposition onto an Al_2O_3 (0001) substrate has been studied. The high-temperature phase with manganese concentration x ≈ 0.53 and the Curie temperature T _C ~ 200–300 K is shown to form near the substrate at the initial stage of the film growth. In this case, high values E ≥ 6.8 J/cm^2 favor the stabilization of this phase over all film thickness, while low values E = 2.6–5.7 J/cm^2 lead to a decrease in the manganese concentration in the upper film layer and the formation of additional “low–temperature” phase with T _C ≈ 30–50 K provided by silicides MnSi and Mn_4Si_7 crystallites.
Электроакустическое возбуждение спиновых волн и их детектирование за счет обратного спинового эффекта Холла
Authors: Ползикова Н.И. , Алексеев С.Г. , Лузанов В.А. , Раевский А.О.
Published: October 2018

Abstract —In this paper, we present theoretical and experimental results on the excitation and detection of spin waves and spin currents in multifrequency bulk acoustic wave resonators containing iron–yttrium garnet (YIG) films in contact with the Pt film. Acoustically excited magnetic precession under the resonator conditions was established to produce spin pumping that also has a resonance character. A significant asymmetry in the frequency dependence of the voltage signal detected on the Pt film is revealed with respect to the frequency of the magnetoelastic resonance and is confirmed by theoretical calculations. Acoustic resonator spectroscopy in combination with the electric detection of magnetic dynamics using the inverse spin Hall effect is shown to be of interest for studying the dispersion of spin waves, as well as magnetic and magnetoelastic parameters of ferromagnetic films.
Затухание спиновой прецессии в гетероструктурах манганит/нормальный металл
Authors: Шайхулов Т.А. , Овсянников Г.А.
Published: October 2018

Abstract —Temperature dependence of attenuation of magnetic spin precession in two-layer structures with a Pt top layer based on a La_0.7Sr_0.3MnO_3 (LSMO) epitaxial manganite film is studied by measuring the width of a ferromagnetic resonance (FMR) line. Ferromagnetic resonance in thin ferromagnetic manganite films is used for the creation of a spin current at the interface between the metallic and ferromagnetic layers. A significant increase in a width of a line in FMR spectrum in two-layer structures due to generation of a spin current, heterogeneity of a ferromagnetic layer, two-magnon scattering, and eddy current is discussed.
Оптические и магнитооптические свойства многослойных наноразмерных плeнок [Co/TiO-=SUB=-2-=/SUB=-]-=SUB=-n-=/SUB=-
Authors: Павлов В.В. , Усачeв П.А. , Нефeдов С.Г. , Новицкий Н.Н. , Писарев Р.В. , Стогний А.И.
Published: October 2018

Abstract —The optical and magneto-optical properties of the metal–dielectric multilayer [Co/TiO_2]_ n structures with 2–4-nm-thick layers prepared on a silicon substrate Si(001) by ion-beam deposition have been studied. The complex permittivity of multilayer [Co/TiO_2]_ n structures has been measured by the optical ellipsometry technique in the spectral range of 0.6–5.6 eV and analyzed using the optical reflection matrices for isotropic multilayer dielectric structures taking into account the optical losses and also using the method of anisotropic effective medium. The magneto-optical Kerr effect has been measured by the polarimetric technique in the spectral range of 1.2–4.5 eV in the polar and longitudinal geometries. The magnetic anisotropy type is determined on the base of the field dependences of the magneto-optical Kerr effect. It is found that the nanosized [Co/TiO_2]_ n structures can be considered as artificial optically uniaxial media with a strong magnetic and optical anisotropy at room temperature.
Влияние ориентации магнитного момента зонда магнитно-резонансного силового микроскопа на спектры спин-волновых резонансов
Authors: Скороходов Е.В. , Сапожников М.В. , Горев Р.В. , Володин А.П. , Миронов В.Л.
Published: October 2018

Abstract —The ferromagnetic resonance in an array of permalloy microstrips 3000 × 500 × 30 nm^3 in size, which are ordered on a rectangular 3.5 × 6 μm^2 lattice, is studied using magnetic resonance force microscopy with strong probe–sample interaction. This interaction induces intricate modifications of the observed spectra, which are manifested both in line splitting and in changes in shape. The dependences of the observed spectra on the sample–probe distance and the orientation of the magnetic moment of the probe are analyzed.
Оптические эффекты в магнитных гиперболических метаматериалах
Authors: Помозов А.Р. , Колмычек И.А. , Ганьшина Е.А. , Волкова О.Ю. , Леонтьев А.П. , Напольский К.С. , Мурзина Т.В.
Published: October 2018

Abstract —We present the results of synthesis of arrays of gold and bilayer Au/Ni nanorods in a matrix of porous anodic alumina and of experimental investigation and numerical simulation of their optical and magnetooptical properties. We show that the spectra of these structures have two singular features located near 520 nm and in the range of 700–800 nm. Au/Ni nanorods exhibit a significant modulation and enhancement of the magnetooptical intensity effect in the range of the long-wavelength resonance. Experimentally observed features agree with results of numerical simulation.
Детекторы циркулярно-поляризованного излучения на основе полупроводниковых гетероструктур с барьером Шоттки CoPt
Authors: Кудрин А.В. , Здоровейщев А.В. , Вихрова О.В. , Дорохин М.В. , Калентьева И.Л. , Дёмина П.Б.
Published: October 2018

Abstract —In this paper, we showed the possibility of practical realization of circularly polarized radiation detectors based on a planar photoresistor using the effect of magnetocircular dichroism in the CoPt layer, as well as based on structures using the spin filtration by the CoPt layer of photogenerated spin-polarized charge carriers. The spin filtration process is established to allow increasing the detection efficiency of up to 1.3%.