99 research outputs found

    Tetra­aqua­bis­[2-(2-oxo-2,3-dihydro-1,3-benzoxazol-3-yl)acetato]­zinc

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    The ZnII ion in the title compound, [Zn(C9H6NO4)2(H2O)4], is located on an inversion center and is octa­hedrally coordinated by two 2-(2-oxo-2,3-dihydro-1,3-benzoxazol-3-yl)acetate anions in axial sites and four water mol­ecules in equatorial positions. In the crystal, O—H⋯O hydrogen bonds between the coordinated water mol­ecules and carbon­yl–carboxyl­ate O atoms lead to pleated sheets parallel to (001)

    Bis(acetyl­acetonato-κ2 O,O′)(2-amino-1-methyl-1H-benzimidazole-κN 3)oxido­vanadium(IV)

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    The title mixed-ligand oxidovanadium(IV) compound, [VO(C5H7O2)2(C8H9N3)], contains a VIV atom in a distorted octahedral coordination, which is typical for such complexes. The vanadyl group and the N-heterocyclic ligand are cis to each other. The coordination bond is located at the endocyclic N atom of the benzimidazole ligand. Intra­molecular hydrogen bonds between the exo-NH2 group H atoms and acetyl­acetonate O atoms stabilize the crystal structure

    Airborne hyperspectral discrimination of tree species with different ages using discrete wavelet transform

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    In this article, the capability of discrete wavelet transform (DWT) to discriminate tree species with different ages using airborne hyperspectral remote sensing is investigated. The performance of DWT is compared against commonly used traditional methods, i.e. original reflectance and first and second derivatives. The hyperspectral data are obtained from Thetford forest of the UK, which contains Corsican and Scots pines with different ages and broadleaved tree species. The discrimination is performed by employing three different spectral measurement techniques (SMTs) including Spectral Angle Mapper (SAM), Spectral Information Divergence (SID), and a combination of SAM and SID. Five different mother wavelets with a total of 50 different orders are tested. The wavelet detail coefficient (CD) from each decomposition level and combination of all CDs plus the approximation coefficient from the final decomposition level (C-All) are extracted from each mother wavelet. The results show the superiority of DWT against the reflectance and derivatives for all the three SMTs. In DWT, C-All provided the highest discrimination accuracy compared to other coefficients. An over- all accuracy difference of about 20 – 30% is observed between the finest coefficient and C-All. Amongst the SMTs, SID provided the highest accuracy, while SAM showed the lowest accuracy. Using DWT in combination with SID, an overall accuracy up to around 71.4% is obtained, which is around 13.5%, 14.7%, and 27% higher than the accuracies achieved with reflectance and first and second derivatives, respectively

    On the Concept of “Complexity” in Radiation Physics

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    Abstract: The concept of “complexity” is considered in relation to radiation processes in condensed matter. It is shown that a combination of such properties as nanoscale, fractality, low dimension, chirality, and hierarchy in combination with high nonequilibrium create conditions for the manifestation of unusual “emergent” radiation effects (radiation synergetics, great dose reduction of threshold radiation effects, etc.). Examples of radiation effects in living and inanimate systems, interpreted within the framework of the concept of “complexity”, are presented. An overview of both previously obtained and new results is presented. © 2022, Pleiades Publishing, Ltd.Russian Foundation for Basic Research, РФФИ: 21-12-00392This work was supported by the Russian Foundation for Basic Research, project no. 21-12-00392

    Современное состояние и перспективы развития технологии органогалогенидных перовскитных солнечных ячеек: кристаллическая структура и формирование тонких пленок, морфология, обработка, деградация и повышение стабильности с использованием углеродных нанотрубок

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    The fundamental problems of the modern state of the studies of organic-inorganic organo-halide perovskites (OHP) as basis for high efficiency thin film solar cells are discussed. Perovskite varieties and background properties are introduced. The chronology of development of the studies in this direction has been presented — structural aspects of these OHP perovskites, from early 2D to recent 3D MAPbI3 perovskites and important technological aspects of smooth thin film structure creation by various techniques, such as solvent engineering, spin- and dip-coating, vacuum deposition, cation exchange approach, nanoimprinting (particularly, a many-sided role of polymers). The most important theoretical problems such as electronic structure of lattice, impurity and defect states in pure and mixed perovskites, suppressed electron-hole recombination, extra-long lifetimes, and diffusion lengths are analyzed. Degradation effects associated with moisture and photo irradiation, as well as degradation of metallic electrodes to OHP solar cells have been considered. The application of carbon nanostructures: carbon nanotubes (CNT) and graphene as stable semitransparent charge collectors to OHP perovskites is demonstrated on the example of original results of authors.Рассмотрены фундаментальные проблемы современного состояния исследований в области органо-неорганических органогалогенидных перовскитов (ОГП) в качестве основы для создания солнечных ячеек с повышенной эффективностью. Приведены данные о разнообразии перовскитов и их основных свойствах. Дана хронология развития исследований в данном направлении — структурные аспекты ОГП-перовскитов, от самых первых двумерных до современных трехмерных перовскитов с формулой MAPbI3, а также важных технологических аспектов создания структуры гладких тонких пленок с использованием разнообразных методов, в частности, подбора растворителей, нанесения покрытий методами центрифугирования и погружения, вауумного осаждения,технологии катионного обмена, наноимпринта (в особенности, разносторонней роли полимеров). Проанализированы наиболее важные теоретические проблемы, в частности, электронная структура решетки, дефектно-примесные состояния в чистых и смешанных перовскитах, подавление электронно-дырочной рекомбинации, сверхбольшие времена жизни и диффузионные длины. Рассмотрены эффекты деградации, связанные с влажностью и фотооблучением, а также деградация металлических электродов на солнечных ячейках на основе ОГП. Продемонстрировано применение углеродных наноструктур — углеродных нанотрубок (УНТ) и графена — в качестве стабильных полупрозначных коллекторов заряда на поверхности ОГП-перовскитов на примере оригинальных результатов, полученных авторами

    A review of applying second-generation wavelets for noise removal from remote sensing data.

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    The processing of remotely sensed data includes compression, noise reduction, classification, feature extraction, change detection and any improvement associated with the problems at hand. In the literature, wavelet methods have been widely used for analysing remote sensing images and signals. The second-generation of wavelets, which is designed based on a method called the lifting scheme, is almost a new version of wavelets, and its application in the remote sensing field is fresh. Although first-generation wavelets have been proven to offer effective techniques for processing remotely sensed data, second-generation wavelets are more efficient in some respects, as will be discussed later. The aim of this review paper is to examine all existing studies in the literature related to applying second-generation wavelets for denoising remote sensing data. However, to make a better understanding of the application of wavelet-based denoising methods for remote sensing data, some studies that apply first-generation wavelets are also presented. In the part of hyperspectral data, there is a focus on noise removal from vegetation spectrum

    The Essence and Features of Functioning of Household Lands of Uzbekistan

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    The socio-economic role of household land plots and personal subsidiary farms is studied, the definitions of their terms are given, and the role of the household land plot in ensuring food security of the country and increasing the export potential of fruits and vegetables is considered. The reasons of higher efficiency of cultivation of agricultural production in personal subsidiary farms in comparison with other forms of managing in agriculture, and also features of use of household land plots are studied
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