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Searching For Wide Binary Stars with Non-coeval Components in the Southern Sky

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Research in Astronomy and Astrophysics 2023年第5期23卷 230-235页

作者： Alexey Kniazev oleg malkov South African Astronomical Observatory Cape Town7935South Africa Southern African Large Telescope Cape Town7935South Africa Special Astrophysical Observatory Nizhnij ArkhyzKarachai-Circassia369167Russia Sternberg State Astronomical Institute MoscowUniversitetsky ave.13Russia Institute of Astronomy Russian Academy of Sciences48 Pyatnitskaya St.Moscow 119017Russia

We have completed our observational program to search for wide binary systems with non-coeval components in the southern sky and report our results *** final set of four systems was spectroscopically investigated in this *** binary systems with components of different ages were found among *** into account our previous studies,we estimate the fraction of such binaries(i.e.,binaries formed,presumably,by capture)to be not higher than 0.06%.The study will be continued on the northern sky.

关键词： (stars:)binaries general-(stars:)binaries visual-stars formation

Variable binaries and variables in binaries in the Binary star DataBase

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Research in Astronomy and Astrophysics 2019年第3期19卷 7-12页

作者： Dana Kovaleva oleg malkov Pavel Kaygorodov Institute of Astronomy Russian Academy of Sciences

The Binary star DataBase(BDB, http://***) combines data from catalogs of binary and multiple stars of all observational types. There is a number of ways for variable stars to form or to be a part of binary or multiple... 详细信息

关键词： astronomical data bases-stars binaries general-stars variables general

Statistical relations between stellar spectral and luminosity classes and stellar effective temperature and surface gravity

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Research in Astronomy and Astrophysics 2020年第9期20卷 183-191页

作者： oleg malkov Dana Kovaleva Sergey Sichevsky Gang Zhaol Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijjing 100012China Institute of Astronomy Russian Academy of Sciences48 Pyatnitskaya St.Moscow 119017Russia

We have determined new statistical relations to estimate the fundamental atmospheric parameters of effective temperature and surface gravity,using MK spectral classification,and vice *** relations were constructed based on the published calibration tables(for main sequence stars)and observational data from stellar spectral atlases(for giants and supergiants).These new relations were applied to field giants with known atmospheric parameters,and the results of the comparison of our estimations with available spectral classification have been quite satisfactory.

关键词： stars:fundamental parameters

Study of Principal Catalogues of Visual Double Stars

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International Journal of Astronomy and Astrophysics 2015年第4期5卷 267-274页

作者： Yikdem Mengesha Gebrehiwot Solomon Belay Tessema oleg malkov Astronomy and Astrophysics Research Division Entoto Observatory and Research Center (EORC) Addis Ababa Ethiopia Institute of Astronomy Russian Academy Sciences Moscow Russia

The goal of this study is to develop a tool for detection of errors and misprints in principal catalogues of visual double stars. Modern statistical investigations of visual doubles (which are about 130 thousand, and they represent the most numerous observational type of binaries) are based almost exclusively on data, listed in those catalogues. So their correction is a challenging task, otherwise the statistics of visual binaries can be biased. Study of individual stars should also be based on correct data. We have presented tools to detect some of errors in the catalogues, especially, to indicate cases i) when positional information on components of a pair is contradictory, and ii) when a double star or its component is included in a catalogue twice, under different names.

关键词： Visual Binary Star Positional Inconsistency Data Duplication Reference Coordinates Additional Component Coordinates

Long-period eclipsing binaries:towards the true mass-luminosity *** test sample,observations and data analysis

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Research in Astronomy and Astrophysics 2020年第8期20卷 169-176页

作者： Alexei Yu.Kniazev oleg Yu.Maikov Ivan Yu.Katkov Leonid N.Berdnikov South African Astronomical Observatory P.O.Box 9ObservatoryCape Town7935South Africa Southern African Large Telescope P.O.Box 9ObservatoryCape Town7935South Africa Sternberg Astronomical Institute Lomonosov Moscow State UniversityMoscow119992Russia Institute of Astronomy of RAS Moscow 119017Russia New York University Abu Dhabi PO Box 129188Abu DhabiUAE Center for Astro Particleand Planetary PhysicsNYU Abu DhabiPO Box 129188Abu DhabiUAE

The mass-luminosity relation is a fundamental law of *** have suggested that the currently used mass-luminosity relation is not correct for the M/M⊙>2.7 range of mass since it was created utilizing double-lined eclipsing binaries,where the components are synchronized and consequently change each other's evolutionary *** exclude this effect,we have started a project to study longperiod massive eclipsing binaries in order to construct radial velocity curves and determine masses for the *** outline our project and present the selected test sample together with the first HRS/SALT spectral observations and the software package,FITTING BINARY STARS(FBS),that we developed for the analysis of our spectral *** the first result,we present the radial velocity curves and best-fit orbital elements for the two components of the FP Car binary system from our test sample.

关键词： stars:luminosity function mass function stars:binaries:spectroscopic

The Silk roads: phylogeography of Central Asian dice snakes (Serpentes: Natricidae) shaped by rivers in deserts and mountain valleys

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Current Zoology 2024年第2期70卷 150-162页

作者： Daniel Jablonski Konrad Mebert Rafaqat Masroor Evgeniy Simonov oleg Kukushkin Timur Abduraupov Sylvia Hofmann Department of Zoology Comenius University in BratislavaBratislavaSlovakia Global Biology BirrSwitzerland Pakistan Museum of Natural History ShakarparianIslamabadPakistan Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscowRussia T.I.Vyazemski Karadag Scientific Station-Nature Reserve—Branch of A.0.Kovalevsky Institute of Biology of the Southern Seas TheodosiaCrimea Zoological Institute of the RAS Saint PetersbourgRussia Institute of Zoology Academy of Sciences of the Republic of UzbekistanYunusabadTashkentUzbekistan Museum Koenig Bonn LIBLeibniz Institute for the Analysis of Biodiversity ChangeBonnGermany UFZ-Helmholtz Centre for Environmental Research Department of Conservation BiologyPermoserstrasse 1504318 LeipzigGermany

Influenced by rapid changes in climate and landscape features since the Miocene,widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic *** dice snake Natrix tessellata,widely distributed in the Western Palearctic is one such *** aimed to resolve a detailed phylogeography of *** with a focus on the Central Asian clade with 4 and the Anatolia clade with 3 mitochondrial lineages,trace their origin,and correlate the environmental changes that affected their distribution through *** expected time of divergence of both clades began at 3.7 Mya in the Pliocene,reaching lineage differentiation approximately 1 million years *** genetic diversity in both clades is rich,suggesting different ancestral areas,glacial refugia,demographic changes,and colonization *** Caspian lineage is the most widespread lineage in Central Asia,distributed around the Caspian Sea and reaching the foothills of the Hindu Kush Mountains in Afghanistan,and Eastern European lowlands in the *** distribution is limited by deserts,moun-tains,and cold steppe ***,Kazakhstan and Uzbekistan lineages followed the Amu Darya and the Syr Darya water systems in Central Asia,with ranges delimited by the large Kyzylkum and Karakum *** the western side,there are several lineages within the Anatolia clade that converged in the central part of the peninsula with 2 being endemic to Western *** distribution of both main clades was affected by expansion from their Pleistocene glacial refugia around the Caspian Sea and in the valleys of Central Asia as well as by environmental changes,mostly through aridification.

关键词： biogeography colonization Eurasia genetic diversity mitochondrial DNA Paratethys refugia water snakes.

Enhanced electric-field induced strain in Eu3+ doped 0.67BiFeO3-0.33BaTiO3 lead-free piezoelectric ceramics

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Journal of Rare Earths 2024年第9期42卷 1747-1754页

作者： Wei Li Tongxiang Liang Xiang He Vyunov oleg Dongfang Pang Shan Wu College of Rare Earths Jiangxi University of Science and Technology Key Laboratory of High Performance Ceramics and Ultrastructure Shanghai Institute of CeramicsChinese Academy of Sciences

Lead-free ferroelectric ceramics,0.67Bi1-xEuxFeO3-0.33BaTiO3（BF-BT-xEu,x=0-0.02）,were prepared via a solid-state reaction,The effect of Eu3+doping on the microstructure,dielectric properties,ferroelectric properties,and electric-field-induced strain was *** X-ray diffraction（XRD） results indicate the presence of a mixed phase of tetragonal and rhombohedral at the morphotropic phase boundary（MPB）.Doping with an appropriate amount of Eu3+reduces the Fe3+content and decreases the leakage current in the binary system.A converse piezoelectric coefficient(d33*) of 392 pm/V is obtained at BF-BT-0.003Eu under an electric field of 60 kV/cm at room temperature,which has a Curie temperature（TC） of 414℃,The unipolar strain and d33* of BF-BT-0.003Eu ceramics increase to 0.438%and 730 pm/V at 125℃ The field-induced strain response of the BF-BT-0.003Eu ceramics is greater than that of 0.67BF-0.33BT,mainly due to its optimal grain size,reduction of leakage current,and coexistence of ferroelectric-relaxation phases,BF-BT-0.003Eu ceramic is a lead-free candidate for high-temperature actuator applications.

关键词： Ferroelectric Field-induced strain Ceramics Lead-free Rare earths

伯醇对镍基催化剂在转移氢化反应中的抑制作用研究

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Chinese Journal of Catalysis 2024年第3期58卷 168-179页

作者： Nikolay Nesterov Alexey Philippov Vera Pakharukova Evgeny Gerasimov Stanislav Yakushkin oleg Martyanov 博列斯科夫催化研究所俄罗斯新西伯利亚

本文研究了在转移加氢条件下,不同类型醇作为氢供体对镍基催化剂在苯并呋喃加氢反应中的活性影响.结果表明,使用异丙醇作为氢供体时,苯并呋喃的加氢过程为底物先发生脱芳构化,然后再进行脱氧反应.然而,当使用伯醇如甲醇、乙醇和正丙醇... 详细信息

本文研究了在转移加氢条件下,不同类型醇作为氢供体对镍基催化剂在苯并呋喃加氢反应中的活性影响.结果表明,使用异丙醇作为氢供体时,苯并呋喃的加氢过程为底物先发生脱芳构化,然后再进行脱氧反应.然而,当使用伯醇如甲醇、乙醇和正丙醇作为氢供体时,会导致镍基催化剂的不可逆失活.针对这一现象,进一步研究了伯醇使镍基金属催化剂失活的机理.结果表明,在250°C条件下,催化剂与伯醇的相互作用会导致形成非活性的碳化物Ni_(3)C,并且镍金属颗粒在氧化铝载体表面会发生烧结和偏析.

关键词：苯并呋喃转移加氢超临界共沉淀 Ni催化剂醇

从BRDF到BPDF:遥感反演基础模型的演进初探

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中国科学:信息科学 2024年第8期54卷 2001-2020页

作者：尚可晏磊张飞舟褚君浩杨彬刘思远 Kevin TANSEY 贾秀萍 oleg DUBOVIK 张子晗李飞北京大学地球与空间科学学院遥感与地理信息系统研究所北京大学空间信息集成与3S工程应用北京市重点实验室中国科学院上海技术物理研究所红外物理国家重点实验室湖南大学电气与信息工程学院中国兵器工业导航与控制技术研究所 School of Geography Geology and the Environment University of Leicester School of Engineering and Technology The University of New South Wales Laboratoire d'Optique Atmosphérique CNRS/Université Lille

光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感... 详细信息

光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感基础上考虑垂直于电磁波传播方向的二维偏振矢量特性(强度+方向)就能深化为矢量遥感体系,从而有望精确刻画反射光中蕴含的多种信息,提升植被参数反演精度.刻画偏振反射空间分布的双向偏振分布函数BPDF目前存在精度低、泛化性差等问题,因此进一步探索矢量遥感基础理论,构建通用性强的植被矢量遥感基础模型具有迫切的现实需求.本文旨在利用光子与植被元素的相互作用构建通用性较强的植被BPDF物理模型.首先基于光子–植被元素相互作用的光谱不变原理,提出基于方向逃逸概率的植被BPDF物理模型基础形式,并基于植被单次反射的辐射传输理论推导模型解析表达;随后通过考虑叶片散射随干物质含量的变化,提出光谱不变原理优化表达并推导模型通用表达式;最后分别利用三维矢量辐射传输模型和多尺度实测数据实现模型的正演直接验证和间接验证.结果表明,本文构建的BPDF物理模型的解析表达和通用表达在不同植被场景下,对偏振反射率的正演均方根误差可达0.001以内,与矢量辐射传输模型正演结果在半球空间内具有很强一致性,在多尺度实测数据也简洁验证了模型关系的稳定性,模型R2普遍高于0.9.相比于现存植被偏振反射模型,本文构建的模型兼具物理机理、简洁形式、可接受的参数化方案、较高精度和较强泛化能力,对浓密植被具备通用性,为在BRDF一维标量遥感的基础上进一步考虑BPDF二维偏振特性从而形成矢量遥感体系这一转变过程提供了理论基础和探索性方案.

关键词：植被 BPDF 矢量遥感物理模型偏振

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