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1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shadrin K. V., Yakovleva Yu. A., Kryukova O. V., Makarskaya G. V., Tarskikh S. V., Pyankov V. F., Pakhomova V. G., Gerasimova Yu. V., Yaroslavtsev R. N., Vorobyev S. A., Stolyar S. V.
Заглавие : Influence of arabinogalactan-coated selenium nanoparticles on the formation of free radicals in Ehrlich ascites carcinoma cells
Колич.характеристики :8 с
Место публикации : BioNanoScience. - 2024. - Vol. 14, Is. 1. - P.268-275. - ISSN 21911630 (ISSN), DOI 10.1007/s12668-023-01251-6. - ISSN 21911649 (eISSN)
Примечания : Cited References: 40
Аннотация: The antioxidant properties of selenium nanoparticles coated with arabinogalactan have been studied. The nanoparticles were characterized by transmission electron microscopy and infrared spectroscopy. Arabinogalactan-coated selenium nanoparticles were incubated together with Ehrlich ascitic carcinoma cells and then exposed to microwave radiation. The antioxidant properties of selenium nanoparticles were evaluated using chemiluminescent analysis. The viability of Ehrlich ascitic carcinoma cells under microwave irradiation and incubation with selenium nanoparticles was assessed by flow cytometry. Under conditions of exposure to experimental tumor cells of microwave radiation, the concentration of free radicals in the cells did not change. The effect of arabinogalactan-coated selenium nanoparticles on tumor cells is expressed as an increase in the delay time for the activation of the antioxidant system.
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2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Muzalevskiy K. V., Walke J. P., Brakhasi F., Ye N., Wu X., Shen X.
Заглавие : On the use of dual-polarized multi-angular observations of P-band brightness temperature for soil moisture profile retrieval in thawed mineral soil
Колич.характеристики :24 с
Место публикации : Int. J. Remote Sens. - 2024. - Vol. 45, Is. 5. - P.1498-1521. - ISSN 01431161 (ISSN), DOI 10.1080/01431161.2024.2313993. - ISSN 13665901 (eISSN)
Примечания : Cited References: 37. - The work was supported by the State assignment of Kirensky Institute of Physics [FWES-2021-0034]; Australian Research Council funding [DP170102373 and LE150100047]. The work was carried out within the state assignment of Kirensky Institute of Physics and the Australian Research Council funding (DP170102373 and LE150100047) that was used to collect the P-band data
Аннотация: This article investigated the possibility of remotely sensing the soil moisture profile in thawed soil from multi-angular dual-polarized brightness temperature (TB) observations at P-band frequencies of 750 MHz and 409 MHz using a modified Burke model. Moreover, it was found that an excellent agreement (coefficient of determination R2 = 0.999 and root-mean-square error (RMSE) no more than RMSE = 0.6 K) could be achieved between the Njoku coherent brightness temperature model and the modified Burke model by introducing a reflectivity from the air-soil interface that takes into account the phases of the multiple re-reflected waves in the underlying layers. Based on the modified Burke model, the depths from which apparent moisture and temperature could be retrieved in a dielectrically-inhomogeneous, non-isothermal soil were investigated, being approximately ten times less than the depth for which apparent soil temperature could be retrieved. In general, the thickness of the emitting layer depends on the TB look angle and polarization, along with the moisture and temperature profiles of the soil. It was also shown that due to the effect of the Brewster angle, the H-polarization of TB was twice as sensitive (4 K/1%) to changes in volumetric soil moisture than V-polarization (1.9 K/1%). Based on multi-angular (10°-50°) observations of TB at H- and V-polarizations, a method of moisture profile retrieval in the top 5–15 cm soil (depending on surface moisture) was proposed using an exponential fitting function, the parameters of which are found in the course of solving the inverse problem. A decrease in the sensing frequency from 750 MHz to 409 MHz makes it possible to increase the accuracy of soil moisture profiles retrieval by a factor of two, being from RMSE = 1.6% (R2 = 0.946) to RMSE = 0.85% (R2 = 0.982) in the top 15 cm layer of soil. The conducted investigation shows the promise of using P-band observations of TB for soil moisture profile retrieval.
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3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Afonin A. O., Alexandrovsky A. S., Govorun I. V., Leksikov A. A., Ugryumov A. V., Ogorodnikov D. K.
Заглавие : Dual band HTSC power limiter
Колич.характеристики :7 с
Место публикации : J. Sib. Fed. Univ. Math. Phys. - 2024. - Vol. 17, Is. 2. - P.162-168. - ISSN 19971397 (ISSN); Журн. СФУ. Матем. и физ.
Примечания : Cited References: 10
Аннотация: A new construction of dual band HTSC power limiter is proposed. The device consists of two microstrip bandpass filters. Each filter consists of two quarter-wave resonators which couple through a composite half-wave resonator with HTSC-element. The prototype of the device in the open mode has operation passband of about 10% and 11% with central frequency being equal to 1.48 GHz and 2.03 GHz, the minimum loss in the passband is equal 1.9 dB and 1.7 dB for LF-channel and HF-channel correspondingly. The transfer characteristics of the device were investigated in the case of microwave power level up to 3.15 W.Предложена новая конструкция ВТСП ограничителя мощности с двумя рабочими полосами. Ограничитель содержит два микрополосковых полосно-пропускающих фильтра. Каждый фильтр состоит из двух четвертьволновых резонаторов, которые связаны между собой через составной полуволновый резонатор, содержащий пленку из высокотемпературного сверхпроводника. Макет устройства в открытом режиме имеет ширины рабочих полос пропускания 10% и 11% с центральными частотами 1.48 ГГц и 2.03 ГГц. Минимальные вносимые потери составили 1.9 дБ и 1.7 дБ для НЧ- и ВЧ-каналов соответственно. Передаточные характеристики устройства были исследованы до уровня СВЧ-мощности 3.15 Вт.
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4.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Muzalevskiy K. V., Mikhaylov M. I., Ruzicka Z.
Заглавие : Calibration of UWB UAV radar for the remote measurement of reflection coefficient
Коллективы : IEEE Ural-Siberian Conference on Biomedical Engineering, Radioelectronics and Information Technology
Место публикации : IEEE Ural-Siberian Conference on Biomedical Engineering, Radioelectronics and Information Technology (USBEREIT). - 2023. - P.105-108. - , DOI 10.1109/USBEREIT58508.2023.10158870
Примечания : Cited References: 16. - The investigation supported by the Russian Science Foundation and the Krasnoyarsk Regional Science Foundation, project № 22-17-20042
Аннотация: In this work, the possibility of the remote measurement of reflection coefficient in the ultra-wide frequency range from 425 MHz to 1010 MHz from the board of unmanned aerial vehicle (UAV) using ultra-wide band (UWB) radar was investigated. With this in mind, the antenna-feeder path of UAV UWB radar is calibrated. The calibration process consisted in measuring the reflection coefficient from the brass mesh sheet at various UAV hovering heights. Printed log-periodic dipole antenna was used as transmitter-receiver antenna. As a result, the antenna return loss in an empty-room and the complex antenna response function of the antenna-feeder path of the UAV UWB radar were found. It is shown that the amplitude of the reflected wave from a brass mesh sheet can be measured with root-mean square error (RMSE), RMSE=0.017 1/m and a determination coefficient (R 2 ) of R 2 = 0.967. Therewith the UAV hovering heights measured by the pulse method and the on-board laser rangefinder correlates with each other with R2=0.999 and with RMSE=3.5cm (distance measurement error of the laser rangefinder is ±1cm, surface irregularities of the brass mesh sheet were no more than 1.5cm). Measured in the frequency range from 500 MHz to 900 MHz, the reflection coefficient from fresh lake water by UAV UWB radar with a relative error of no more than 7.5% (practically does not depend on the height of the UAV hovering, approximately from 2.2 m to 5.2 m) coincides with the calculated one by the Stogryn's formulas.
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5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Lim, Chang S., Aleksandrovsky A. S., Molokeev M. S., Oreshonkov A. S., Atuchin V.
Заглавие : Structural and spectroscopic effects of Li+ substitution for Na+ in LixNa1–xCaLa0.5Er0.05Yb0.45(MoO4)3 upconversion scheelite-type phosphors
Место публикации : Crystals. - 2023. - Vol. 13, Is. 2. - Ст.362. - ISSN 20734352 (eISSN), DOI 10.3390/cryst13020362
Примечания : Cited References: 63. - This study was funded by the Research Program through the Campus Research Foundation funded by Hanseo University in 2022 (2022046)
Аннотация: New triple molybdates LixNa1−xCaLa0.5(MoO4)3:Er3+0.05/Yb3+0.45 (x = 0, 0.05, 0.1, 0.2, 0.3) were manufactured successfully using the microwave-assisted sol-gel-based technique (MAS). Their room-temperature crystal structures were determined in space group I41/a by Rietveld analysis. The compounds were found to have a scheelite-type structure. In Li-substituted samples, the sites of big cations were occupied by a mixture of (Li, Na, La, Er, Yb) ions, which provided a linear cell volume decrease with the Li content increase. The increased upconversion (UC) efficiency and Raman spectroscopic properties of the phosphors were discussed in detail. The mechanism of optimization of upconversion luminescence upon Li content variation was shown to be due to the control of excitation/energy transfer channel, while the control of luminescence channels played a minor role. The UC luminescence maximized at lithium content x = 0.05. The mechanism of UC optimization was shown to be due to the control of excitation/energy transfer channel, while the control of luminescence channels played a minor role. Over the whole spectral range, the Raman spectra of LixNa1−xCaLa0.5(MoO4)3 doped with Er3+ and Yb3+ ions were totally superimposed with the luminescence signal of Er3+ ions, and increasing the Li+ content resulted in the difference of Er3+ multiple intensity. The density functional theory calculations with the account for the structural disorder in the system of Li, Na, Ca, La, Er and Yb ions revealed the bandgap variation from 3.99 to 4.137 eV due to the changing of Li content. It was found that the direct electronic transition energy was close to the indirect one for all compounds. The determined chromaticity points (ICP) of the LiNaCaLa(MoO4)3:Er3+,Yb3+ phosphors were in good relation to the equal-energy point in the standard CIE (Commission Internationale de L’Eclairage) coordinates.
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6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Kubitza, Niels, Xie, Ruiwen, Tarasov I. A., Shen, Chen, Zhang, Hongbin, Wiedwald, Ulf, Birkel, Christina S.
Заглавие : Microwave-assisted synthesis of the new solid-solution (V1–xCrx)2GaC (0 ≤ x ≤ 1), a Pauli paramagnet almost matching the Stoner criterion for x = 0.80
Место публикации : Chem. Mater. - 2023. - Vol. 35, Is. 11. - P.4427-4434. - ISSN 08974756 (ISSN), DOI 10.1021/acs.chemmater.3c00591. - ISSN 15205002 (eISSN)
Примечания : Cited References: 54. - This work has been supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) within CRC/TRR 270, projects B03 and B02, A05 (Project-ID 405553726)
Аннотация: MAX phases that exhibit long-range magnetic order in the bulk are still very hard to synthesize. Chromium and manganese are the cutoff elements when transitioning through the 3dmetals that still form stable full and doped MAX phases, respectively. An iron-based (on the M-site) bulk MAX phase does not exist. Therefore, other strategies to induce long-range magnetic ordering in bulk MAX phases are necessary to open the path to new functional materials. Here, we demonstrate the nonconventional synthesis of a hitherto unknown MAX phase solid-solution (V1–xCrx)2GaC by microwave heating. The full series with 0 ˂ x ˂ 1 (x = 0.20, 0.40, 0.50, 0.60, 0.80) forms almost single phase with minimal differences in their morphology. Their magnetic properties, however, differ rather significantly, with a maximum susceptibility around x = 0.80. Both the experimental and theoretical/ab initio magnetic analysis confirm that the solid-solution (V1–xCrx)2GaC is an itinerant Pauli paramagnet that almost fulfills the Stoner criterion for ferromagnetic order (for compositions with x around 0.80). This is a powerful insight into how chemical composition couples with electronic structure and the resulting bulk magnetic properties because it provides crucial guidelines to produce long-range ordered magnetic MAX phases.
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7.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Muzalevskiy K. V., Fomin S. V., Mikhaylov M. I.
Заглавие : UWB reflectometric method for the measuring of vegetation biometric parameters and soil moisture
Коллективы : IEEE Ural-Siberian Conference on Biomedical Engineering, Radioelectronics and Information Technology
Место публикации : IEEE Ural-Siberian Conference on Biomedical Engineering, Radioelectronics and Information Technology (USBEREIT). - 2023. - P.166-169. - , DOI 10.1109/USBEREIT58508.2023.10158880
Примечания : Cited References: 17. - The investigation supported by the Russian Science Foundation and the Krasnoyarsk Regional Science Foundation, project № 22-17-20042
Аннотация: In this article, a method for the simultaneous measurement of total biomass, vegetation water content, and soil moisture is developed based on ultra-wideband (UWB) nadir observation of the reflection coefficient in the frequency range from 450 MHz to 6 GHz. The proposed method is based on a simple model of plane wave reflection from a vegetation layer with flat boundaries lying on a smooth soil surface. The model does not take into account the phenomena of wave scattering on the vegetation elements and the soil surface roughness. The dielectric constant of the vegetation canopy and soil were calculated based on Ulaby and Mironov dielectric models, respectively. The proposed method was tested using data from PORTOS-93 (INRA) experiments on measuring: total biomass (up to 3.3 kg/m2), water content (43%-89%), height (up to 1m) and volumetric content (up to 0.6-0.8%) of wheat plants, moisture (from 5% to 36%), density and clay fraction content (27%) of the soil. As a result, it was shown, the coefficient of determination (R2) and root-mean-square error (RMSE) appeared to be equal to R2=0.999 and RMSE=2.2% when comparing the original and retrieved values of volumetric soil moisture. The retrieved values of total biomass (vegetation water content) with the coefficient of determination R2=0.999 (0.998) and RMSE=16g/m2 (0.7%) coincide with the original set values. Therewith, the bands from 4 GHz to 6 GHz and from 450 MHz to 1 GHz were used to retrieve the canopy biometric parameters and soil moisture, respectively.
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8.

Вид документа : Однотомное издание
Шифр издания : Описание изобретения к патенту 2793577!-305467153
Автор(ы) : Бабицкий, Александр Николаевич, Боев, Никита Михайлович, Клешнина, Софья Андреевна, Подшивалов, Иван Валерьевич, Горчаковский, Александр Антонович, Соловьев, Платон Николаевич, Изотов, Андрей Викторович, Бурмитских, Антон Владимирович, Крёков, Сергей Дмитриевич, Негодеева, Ирина Александровна
Заглавие : Устройство для измерения шумов тонких магнитных пленок в СВЧ-диапазоне .-
Коллективы : Федеральный исследовательский центр "Красноярский научный центр Сибирского отделения Российской академии наук", Федеральная служба по интеллектуальной собственности (Роспатент), Федеральный институт промышленной собственности
Место публикации : Изобретения. Полезные модели: офиц. бюл. Фед. службы по интеллектуал. собственности (Роспатент). - 2023. - № 10
Аннотация: Изобретение относится к измерительной технике и предназначено для неразрушающего контроля качества магнитных пленок и изучения их высокочастотных характеристик путем регистрации спектральной плотности амплитуды шумов образцов. Устройство содержит параллельный колебательный контур, включающий емкость и индуктивность, в качестве которой используется несимметричная полосковая линия. Внутри линии размещают исследуемый образец тонкой магнитной пленки, а сама линия вместе с образцом размещены внутри магнитной системы, формирующей постоянное магнитное поле. Параллельный колебательный контур соединен через конденсатор с СВЧ-генератором и напрямую с амплитудным детектором, нагруженным на вход низкочастотного анализатора спектра. Техническим результатом является обеспечение возможности измерения магнитных шумов в СВЧ-диапазоне.
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9.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Kuznetsov S. A., Lapanik V. I., Lugouskiy A. A., Timofeev S. N., Sutormin V. S., Zyryanov V. Ya.
Заглавие : Electrically-tunable reflectarrays for millimeter waves based on liquid-crystal-loaded high-impedance surfaces
Коллективы : "Terahertz and microwave radiation: generation, detection and applications", International conference, «Терагерцевое и микроволновое излучение: генерация, детектирование и приложения», конференции с международным участием, Национальный исследовательский ядерный университет МИФИ, Московский государственный университет им. М.В. Ломоносова, Национальный исследовательский центр "Курчатовский институт"
Место публикации : The 5-th International conference "Terahertz and microwave radiation: generation, detection and applications" (TERA-2023): abstract book. - Москва, 2023. - P.11
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Музалевский, Константин Викторович
Заглавие : Особенности радиометрического зондирования влажности тундровых почв в P-диапазоне частот
Колич.характеристики :21 с
Место публикации : Журн. радиоэлектрон. - 2023. - № 12. - ISSN 16841719 (eISSN), DOI 10.30898/1684-1719.2023.12.9; J. Radio Electron.
Примечания : Библиогр.: 25
Аннотация: В данной работе в P-диапазоне частот (409 МГц) теоретически исследуются особенности микроволнового излучения тундровых почв в процессе протаявания деятельного слоя. В вертикальном сечении, почвы деятельного слоя характеризовались профилями объемной влажности, весового содержания органического вещества, временными рядами физической температуры. Радиояркостная температура деятельного слоя тундровых почв рассчитывалась на основе феноменологической модели радиотеплового излучения слоисто-неоднородного неизотермического полупространства. При моделировании радиояркостной температуры использовалась диэлектрическая модель, позволяющая рассчитать действительную и мнимую части относительной комплексной диэлектрической проницаемости тундровых почв с высоким содержанием органического вещества 35%-80%, в диапазоне температур от −30 °С до +25 °С. Показано, что по мере протаявания деятельного слоя тундровых почв наблюдается явление интерференции излучательной способности, амплитуда которой определяется видом вертикального профиля содержания органического вещества. Для рассмотренных видов профилей влажности и содержания органического вещества, интерференцией излучательной способности можно пренебречь при протаявании деятельного слоя на глубину более 18.5 см. В случае, если объемная влажность протаявающей части деятельного слоя почв меньше (или близка к) максимальному содержанию связанной воды, то явление интерференции излучательной способности не наблюдается. Выполненные оценки показали, что средняя глубина зондирования влажности для рассмотренных тундровых почв не превышает 4.5см.In this paper, in the P-band (409 MHz), the features of tundra soils microwave emission are theoretically studied during the thawing of active layer. The soils in vertical section of active layer were characterized by the profiles of volumetric moisture, weight content of organic matter, and time series of physical temperature. The brightness temperature of the active layer of tundra soils was calculated based on the phenomenological model of microwave emission for a stratified non-isothermal half-space. A dielectric model that allows to calculate the real and imaginary parts of the relative complex dielectric constant of tundra soils with a high organic matter content of 35%-80%, in the temperature range from -30C to +25C was used to modeling the brightness temperature. As a result, It was shown that as the active layer of tundra soils thaws, the interference of emissivity is observed, the amplitude of which is determined by the kind of vertical profile of the organic matter content. The interference of emissivity can be neglected when the active layer thaws more than 18.5 cm. If the volumetric moisture of the thawing part of the active layer is less than (or close to) the maximum content of bound water, then interference of emissivity is not observed. Modeling showed that the average sensing depth of tundra soil moisture does not exceed 4.5 cm.
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Solovev P. N., Afonin A. O., Belyaev B. A., Boev N. M., Govorun I. V., Izotov A. V., Ugrymov A. V., Leksikov An. A.
Заглавие : Second harmonic generation as a probe of parametric spin wave instability processes in thin magnetic films
Место публикации : Phys. Rev. B. - 2022. - Vol. 106, Is. 6. - Ст.064406. - ISSN 24699950 (ISSN), DOI 10.1103/PhysRevB.106.064406
Примечания : Cited References: 33. - This work was supported by the Russian Science Foundation under Grant No. 19-72-10047. The equipment of the Krasnoyarsk Regional Center of Research Equipment of Federal Research Center “Krasnoyarsk Science Center SB RAS” was used during the measurements
Аннотация: We have explored the dynamic response of in-plane magnetized thin permalloy films excited by microwave fields of high amplitudes (up to 3 Oe) at 1 GHz. The response was detected using a microstrip line by measuring the second harmonic signal generated by the dynamic components of the uniform magnetization. The data measured at ferromagnetic resonance showed the threshold effect of the Suhl parametric instability process. With the increase of the microwave power above the threshold value, the dynamic response revealed an intricate nonlinear behavior, including the emergence of an additional threshold. This second threshold can be explained in terms of the "stage by stage"process of parametric spin wave excitation following the S theory of Zakharov, L'vov, and Starobinets.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Izotov A. V., Belyaev B. A., Boev N. M., Burmitskikh A. V., Leksikov An. A., Skomorokhov G. V., Solovev P. N.
Заглавие : Tailoring the microwave properties of thin permalloy films using a periodically grooved substrate
Коллективы : Ministry of Science and Higher Education of the Russian Federation [075-11-2019054]
Место публикации : Physica B. - 2022. - Vol. 629. - Ст.413654. - ISSN 0921-4526, DOI 10.1016/j.physb.2021.413654. - ISSN 1873-2135(eISSN)
Примечания : Cited References: 50. - This work was supported by the Ministry of Science and Higher Education of the Russian Federation, agreement number 075-11-2019054 dated November 22, 2019
Предметные рубрики: FERROMAGNETIC-RESONANCE
MAGNETIC-PROPERTIES
ANISOTROPY
FREQUENCY
Аннотация: Thin magnetic films with periodic surface topography are of special interest for microwave applications as their static and dynamic magnetic characteristics can be readily adjusted. In this paper, we explore the capabilities of a simple method for producing large-area periodically patterned films by creating regularly spaced grooves on a substrate using a diamond cutter. For 110-nm-thick films, it was found that the substrate-topography-induced magnetic anisotropy was inversely proportional to the pattern period, which in experimental samples varied from 5 to 20 mu m. Based on the Netzelmann theory, analytical expressions for demagnetization tensor components were obtained, which accord well with the experimental data. The measurements of the natural ferromagnetic resonance spectra demonstrated that the increase of the topography-induced magnetic anisotropy with the decrease of the pattern period led to the increase of the resonance frequency from 0.65 to 1.86 GHz, and to a decrease of the linewidth and effective damping parameter.
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Belyaev B. A., Serzhantov A. M., Balva Y. F., Galeev R. G., Leksikov An. A.
Заглавие : Design for a self-packaged aLl-PCB wideband filter with good stopband performance
Коллективы : IEEE/MTT-S International Microwave Symposium 2021
Место публикации : IEEE Trans. Compon. Packag. Manufact. Tech./ IEEE/MTT-S International Microwave Symposium 2021 (7-10 June 2021 ; Atlanta). - 2022. - Vol. 12, Is. 7. - P.1186-1195. - ISSN 21563950 (ISSN), DOI 10.1109/TCPMT.2022.3183581
Примечания : Cited References: 34. - This work was supported by the Ministry of Science and Higher Education of the Russian Federation, state assignment no. FEFE-2020-0013
Аннотация: A new design of a self-packaged all-PCB wideband filter based on the cascade connection of high-pass and low-pass filters is presented. The novel low-pass and high-pass quasi-lumped filter structure differs from the known ones by the existence of cross-coupling between elements producing transmission zeroes at the desired frequency. It is shown that high order structures make it possible to design a wideband filter having the number of transmission zeros in the low-frequency stopband equal to the order of the applied high-pass filter and the number of transmission zeros in the high-frequency stopband equal to half the order of the low-pass filter. An implementation of two-layer metallization of the capacitor plates made it possible to manufacture all three types of filters using the common technology of multilayer printed circuit boards with a good coincidence of the characteristics of the model and the fabricated filters. The filter fabricated using materials with a rather low-quality factor (F4BM/RO4450B/RO4003C) has demonstrated a good performance: the central frequency is 0.99 GHz, the 1 dB fractional bandwidth is 152%, the minimum in-band loss is 0.3 dB, the selectivity (Δf30dB/Δf3dB) is 1.21, and the 40-dB stopband width is 6.16f0.
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14.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Muzalevskiy K. V., Mikhaylov M. I., Ruzicka Z.
Заглавие : Synthesizing of ultra-wide band impulse by means of a log-periodic dipole antenna. Case study for a radar stand experiment
Коллективы : IEEE International Multi-Conference on Engineering, Computer and Information Sciences 2022
Место публикации : 2022 IEEE International Multi-Conference on Engineering, Computer and Information Sciences, SIBIRCON 2022: IEEE, 2022. - P.1140-1143. - , DOI 10.1109/SIBIRCON56155.2022.10017008
Примечания : Cited References: 20. - The investigation supported by the Russian Science Foundation and the Krasnoyarsk Regional Science Foundation, project № 22-17-20042
Аннотация: In this work, the approach of ultra-wide band pulses synthesizing is proposed using a broadband low-cost log-periodic dipole antenna and a vector network analyzer. Synthesis of UWB pulse (duration of 2.2ns) became possible due to minimization of antenna dispersion by compensation of amplitude and phase-frequency distortions introduced by the antenna into radiated and received pulse. The method had been developed for a down-looking antenna in a monostatic radar configuration. The antenna return loss was calculated using the model of two-port linear network with S-parameters. To calibrate the model, an original amplitude-phase method was proposed that requires measuring the antenna's return loss when the antenna is located only at several heights above the reflecting surface (metal sheet). In this case, the antenna return loss in an empty room does not need to be measured. The proposed method for synthesizing UWB pulses does not require changes in the design of the antenna and can be implemented as an additional software calibration of the antenna-feeder path. The proposed method of UWB pulses synthesizing can be implemented using miniature, low-cost vector network analyzers for environment remote sensing from unmanned aerial vehicle using the UWB impulses.
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15.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Fomin S. V., Muzalevskiy K. V., Karavayskiy A. Yu., Romanov V., Lipshin A., Mikhailets M.
Заглавие : Validation of Dobson's, Schmugge's, and Mironov's dielectric models at four typical agrosoils of Krasnoyarsk and Krasnodar krais
Коллективы : IEEE All-Russian Microwave Conference
Место публикации : Proceedings - 2022 IEEE 8th All-Russian Microwave Conference, RMC 2022. - 2022. - 8th IEEE All-Russian Microwave Conference, RMC 2022 (23 - 25 November 2023, Moscow, Russian Federation) Conference code: 187597. - P.349-352. - , DOI 10.1109/RMC55984.2022.10079332
Примечания : Cited References: 16. - The investigation supported by the Russian Science Foundation and the Krasnoyarsk Regional Science Foundation, project №22-17-20042
Аннотация: In this article, in a wide frequency range from 300 MHz to 2 GHz at a temperature of 20C, the validation of Dobson's, Schmugge's, and Mironov's (with one, two, and three soil water relaxations) dielectric models was carried out using four samples of typical agrosoils taken from the arable layer. Variations in the clay fraction, dry bulk density, and organic matter content of soil samples ranged from 32% to 56%, from 1.1 g/cm3 to 1.7 g/cm3, up to 6.9%, respectively. It is shown that the Mironov's model with two relaxations (M2) has the best accuracy in describing the measured relative complex permittivity (RCP) spectra for all soils in average. The coefficient of determination (R2) and root-mean square error (RMSE) appeared to be equal of Rε'2=0.907 (RMSEε'=0.83) for real and Rε''2=0.960 (RMSEε'' =0.89) for imaginary parts of RCP, when comparing the measured and calculated RCPs. Error of soil moisture retrieval, based on M2 dielectric model and the observations of reflection coefficient at nadir was estimated. For four agricultural soils, it is shown that the retrieved volumetric soil moisture values with the determination coefficient R2=0.975 and RMSE =2% coincide with the true values of soil moisture. It has also been found that small inaccuracies (several tens of percent) in determining the dry bulk density and clay content of soils have practically no effect on the error in retrieving the volumetric soil moisture.
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16.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Muzalevskiy K. V.
Заглавие : Numerical-analytical model of reflection coefficient for rough soil surface in wide frequency range
Коллективы : IEEE All-Russian Microwave Conference
Место публикации : Proceedings - 2022 IEEE 8th All-Russian Microwave Conference, RMC 2022. - 2022. - 8th IEEE All-Russian Microwave Conference, RMC 2022 (23 - 25 November 2023, Moscow, Russian Federation) Conference code: 187597. - P.305-308. - , DOI 10.1109/RMC55984.2022.10079255
Примечания : Cited References: 18. - The investigation supported by the Russian Science Foundation and the Krasnoyarsk Regional Science Foundation, project №22-17-20042
Аннотация: In this work, a numerical-analytical model of reflection coefficient for rough soil surface in wide frequency band was proposed. The field of reflected wave from the rough soil surface is presented as the sum of secondary fields from an infinite set of elementary horizontal scattering plates (with a given average size). The field from each elementary scattering plate is represented as an average field from the result of stochastic interference of an infinite set of coherent elementary sources of secondary waves. The vertical position of the elementary sources is determined by the stochastic height of the soil surface within elementary plate. The case of the coherent component and the total value (coherent+diffuse components) of reflection coefficient is considered. On the basis of the created model of reflection coefficient, a broadband method for simultaneously retrieved the root-mean-square deviation of the stochastic soil surface heights and volumetric soil moisture was developed. The results have a wide application value both for single-frequency and multi-frequency radar and radiometric methods of soil moisture measuring.
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17.

Вид документа : Статья из сборника (выпуск продолж. издания)
Шифр издания :
Автор(ы) : Muzalevskiy K. V., Fomin S. V., Karavayskiy A. Yu.
Заглавие : Optimum frequency range for remote sensing of soil moisture with various texture, density and organic matter content
Коллективы : IEEE International Multi-Conference on Engineering, Computer and Information Sciences 2022
Место публикации : 2022 IEEE International Multi-Conference on Engineering, Computer and Information Sciences, SIBIRCON 2022: IEEE, 2022. - P.1130-1133. - , DOI 10.1109/SIBIRCON56155.2022.10017095
Примечания : Cited References: 28. - The investigation supported by the Russian Science Foundation and the Krasnoyarsk Regional Science Foundation, project №22-17-20042
Аннотация: In this article, the frequency range, within which the dependence of reflectivity on soil moisture is invariant respect to changes in soils texture, dry bulk density and organic matter content, has been established. The analysis is based on dielectric measurements of 16 natural mineral nonsaline soils in the frequency range from 45-100 MHz to 2 GHz. The moisture of soils varied from air dry to the field capacity. The clay, silt and sand content in the soil samples are ranging from 0% to 76%, from 1% to 93%, and from 0 to 100%, respectively. The dry bulk density and organic matter content in soil samples are ranging from 0.7 g/cm3 to 1.8g/cm3, and from 0.6% to 69%, respectively. As a result, it is shown, that the variations in texture, dry bulk density, and organic matter content of soils have the least effect in the frequency range from 125 MHz to 820 MHz (with minimum at a frequency of 350 MHz) on the dispersion of the dependence of refractive index on volumetric moisture. As an example, the case of smooth bare soil surface remote sensing at a frequency of 435 MHz is considered. It is shown that for the entire set of soils, a single calibration curve for conversion of reflectivity to volumetric soil moisture is sufficient to retrieve soil moisture with a root-mean square error of 2.1% and a determination coefficient of 0.981. The established frequency range can be recommended for microwave remote sensing methods of soil moisture measurement, not depended on soils texture.
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sadreev A. F.
Заглавие : Interference traps waves in an open system: bound states in the continuum
Коллективы : Russian Foundation for Basic Research Projects [19-02-00055]
Место публикации : Rep. Prog. Phys. - 2021. - Vol. 84, Is. 5. - Ст.055901. - ISSN 0034-4885, DOI 10.1088/1361-6633/abefb9. - ISSN 1361-6633(eISSN)
Примечания : Cited References: 154. - The work was partially supported by Russian Foundation for Basic Research Projects No. 19-02-00055
Предметные рубрики: FANO RESONANCES
2ND-HARMONIC GENERATION
QUANTUM-SYSTEMS
UNIFIED THEORY
Аннотация: I review the four mechanisms of bound states in the continuum (BICs) in the application of microwave and acoustic cavities open to directional waveguides. The most simple are symmetry-protected BICs, which are localized inside the cavity because of the orthogonality of the eigenmodes to the propagating modes of waveguides. However, the most general and interesting is the Friedrich-Wintgen mechanism, when the BICs are the result of the fully destructive interference of outgoing resonant modes. The third type of BICs, Fabry-Perot BICs, occurs in a double resonator system when each resonator can serve as an ideal mirror. Finally, the accidental BICs can be realized in the open cavities with no symmetry like the open Sinai billiard in which the eigenmode of the resonator can become orthogonal to the continuum of the waveguide accidentally due to a smooth deformation of the eigenmode. We also review the one-dimensional systems in which the BICs occur owing to the fully destructive interference of two waves separated by spin or polarization or by paths in the Aharonov-Bohm rings. We make broad use of the method of effective non-Hermitian Hamiltonian equivalent to the coupled mode theory, which detects BICs by finding zero-width resonances.
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Belyaev B. A., Boev N. M., Gorchakovskii A. A., Izotov A. V., Solovev P. N.
Заглавие : Structure constant and grain size determination by ferromagnetic resonance in thin magnetic films
Место публикации : Russ. Phys. J. - 2021. - Vol. 64, Is. 1. - P.1-8. - ISSN 10648887 (ISSN), DOI 10.1007/s11182-021-02293-7
Примечания : Cited References: 28. - This work was financially supported by Project N 20-42-24290 from the Russian Foundation for Basic Research, administrative support from Krasnoyarsk Krai, Scientific Foundation of Krasnoyarsk Krai, and AO "Radiosvyaz"
Аннотация: The paper shows that the structure constant and the average crystal grain size of anisotropic nanocrystalline magnetic film can be determined by analyzing the shape of the microwave absorption peak in sweeping the external magnetic field along the hard magnetization axis. In the theory of magnetization ripple, the surface energy density of the local magnetic anisotropy is connected with the structure constant, which can be used to determine the quality of nanocrystalline films. The effectiveness of the structure constant measurements is demonstrated on a 300-nm-thick nanocrystalline Co–P film. Spectral data on the microwave absorption are collected in the ~1 mm2 region of the film using a scanning ferromagnetic resonance spectrometer. The structure constant obtained from the spectral analysis allows detecting the average grain size of the magnetic film, which is in good agreement with transmission electron microscopy observations.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Muzalevskiy K. V.
Заглавие : A new method for remote sensing of moisture profiles in the arable layer at three frequencies; experimental case study
Место публикации : Int. J. Remote Sens. - 2021. - Vol. 42, Is. 7. - P.2377-2390. - ISSN 01431161 (ISSN), DOI 10.1080/01431161.2020.1851795
Примечания : Cited References: 35. - This work was supported by the Russian Foundation for Basic Research (grant No. 18-05-00405) in part of the sensing depth investigation and retrieving soil moisture. The method of the formation of radio impulses was created in part of SB RAS project No. 0356-2019-0004
Аннотация: In this paper, the possibilities of remote sensing of moisture profiles in the arable layer were theoretically and experimentally studied based on the nadir measurements of reflection coefficients at three frequencies of 1.26 GHz, 796 MHz and 641 MHz. The reflection coefficients were measured by the impulse method during natural cycles of evaporation and moistening of an arable layer at the agricultural field being under steam, located at 56°05ʹN, 92°40ʹ E in the area of the Minino village, Krasnoyarsk region, the Russian Federation. The soil moisture profiles were retrieved in the course of solving the inverse problem, in which the reflection coefficients at different frequencies acted as an informative sign. The root-mean-square error and the determination coefficient (R 2) between retrieved and measured moisture values in the topsoil thickness of 0.15 m were 3.3% and 0.79, respectively. In the course of theoretical calculations, it was shown that in practice, it is impossible to predict the sensing depth of the arable layer without preliminary information on the form of moisture profile. Moreover, the sensing depth depends not only on the form of soil moisture profile but also on frequency. In this regard, it is impossible to correlate the effective soil moisture, retrieved from single-frequency measurements of the reflection coefficient in the approximation of homogeneous topsoil, with the specific thickness of topsoil. The study shows the promise of developing multi-frequency radar systems for remote sensing of soil moisture profiles in the arable layer, the potential of which can be realized on lightweight unmanned area vehicle (UAV) platforms.
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