检索结果-南通市图书馆

Variable binaries and variables in binaries in the Binary star DataBase

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

A new species of Platanus from the Cenomanian(Upper Cretaceous) in eastern Heilongjiang, China

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第4期10卷 1535-1541页

作者： Ge Sun Tatiana.kovaleva Fei Liang Tao Yang Yuhui Feng Key Laboratory of Evolution of Past Life and Environmental Changes in NE Asia Ministry of EducationChangchun 130026China College of Geosciences Jilin UniversityChangchun 130061China College of Paleontology Shenyang Normal UniversityShenyang 110034China

The stratigraphic division and sequence of the Upper Cretaceous sediments in eastern Heilongjiang Province,China,have been ambiguous and controversial,mainly due to a lack of biostratigraphically useful fossils and related radiometric dating.A new species of angiospermous fossil *** heilongjiangensis ***.,from Qitaihe in eastern Heilongjiang has been found in sediments conformably above which zircons from a rhyolitic tuff has been dated by U-Pb radiometric methods as 96.2±1.7 *** that the Upper Houshigou Formation is of Cenomanian *** discovery not only provides new data to improve our stratigraphic understanding of the Houshigou Formation,but also shows that Platanus flourished in the early Late Cretaceous floras of the *** new study also indicates active volcanism taking place in the eastern Heilongjiang region during the Cenomanian of the Late Cretaceous.

关键词： Platanus Cenomanian Upper Cretaceous Dating Qitaihe Heilongjiang

Understanding the Contribution of Innovation to Growth:The Case of China

在线全文

学校读者我要写书评

暂无评论

Understanding the Contribution of Innovation to Growth:The C...

作者： Anastasiia.kovaleva 华东师范大学

学位级别：硕士

2011年以来,中国国内生产总值（GDP）增速不断放缓,为了保持经济持续发展,中国就必须培育有利于增长和提高生产率的创新驱动力。众所周知,中国政府正在制定新的科技进步目标,致力于使创新成为经济增长的主要动力。然而,现在说创新战略... 详细信息

2011年以来,中国国内生产总值（GDP）增速不断放缓,为了保持经济持续发展,中国就必须培育有利于增长和提高生产率的创新驱动力。众所周知,中国政府正在制定新的科技进步目标,致力于使创新成为经济增长的主要动力。然而,现在说创新战略已经产生了令人满意的结果还为时过早。本文旨在确定中国创新发展的制约因素。通过对中国经济增长历程、创新的历史作用、对当今中国经济创新程度的评估以及对关键创新政策领域的深入阐述,本文对上述制约因素进行了研究,并回答了为什么创新的增强不会导致中国经济更高的增长率。研究发现,贸易和外商直接投资的限制、过于依赖实验发展并以牺牲基础研究为代价、倾向于限制国内市场竞争、缺乏自下而上的企业规划、缺乏具有分析思维能力的熟练工人、不够成熟的知识产权环境对充分发挥中国的创新潜力、实现创新驱动的经济增长构成了重大障碍。

关键词：中国经济增长创新

Geomechanical monitoring of rock's massive in zones of breaks

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2005年第S1期15卷 275-278页

作者： M. A. Zhuravkov S. I. Bogdan M. A. kovaleva Belarus State University Minsk 220050 BelarusBelarus State University Minsk 220050 BelarusBelarus State University Minsk 220050 Belarus

For safe development of underground space and especially in areas of geological infringements it is necessary to creat effective system of tracking, forecasting and management for deforming processes in such areas-system of geomechanical monitoring. Besides it is necessary to study and imagine the internal mechanism of deforming processes in such special zones. In the paper some basic aspects of creation of geomechanical monitoring systems for realization of supervision, study and modelling of deforming processes, for modelling and study of the stress-strain state of massif in areas of large-scale underground mining works in view of a block-hierarchical structure of rock’s massive (presence of geological infringements) are considered. In particular such important tasks, as research of deforming processes in areas of geological infringements with the help of GPS-technologies and use of the received results for the modeling; construction of models adequately describing a condition of rock’s massive in area of geological infringement. Some results of researches on study of cavities influence on occurrence of an area of limiting conditions in region of geological infringement and possible shift along infringement are submitted.

关键词： geological infringement shift displacement stress-strain state

Experimental and numerical analyses of nitrogen oxides formation in a high ammonia‑low hydrogen blend using a tangential swirl burner

在线全文

学校读者我要写书评

暂无评论

碳中和(英文) 2022年第1期1卷 291-310页

作者： A.Alnasif S.Mashruk M.kovaleva P.Wang A.Valera-Medina College of Physical Sciences and Engineering Queen’s BuildingCardiff UniversityCardiffWales CF243AAUK Engineering Technical College of Al-Najaf Al-Furat Al-Awsat Technical UniversityNajaf 31001Iraq Institute for Energy Research Jiangsu UniversityJiangsu 212013China

Ammonia has been considered as a novel fuel for decarbonization ***,emissions from combustion systems are still posing a ***,experimental and numerical simulations have been conducted to study the concentration of exhaust emissions(Nitric oxide“NO”,Nitrous oxide“N_(2)O”)from burning the ammonia/hydrogen(NH_(3)/H_(2))blend 85/15(vol%).The effects were measured at various thermal powers ranging 10 to 20 kW and with different Reynolds numbers from 20,000—40,*** experimental points were numerically investigated in the Ansys CHEMKIN-Pro environment employing seven chemical kinetic mechanisms taken from the *** experiments have been undertaken at standard atmospheric *** experimental results showed that both NO and N_(2)O gradually increased when the Reynolds number increased from 20,000 to 40,*** with that,the concentration of NO emissions at the exhaust reported minimum level when the Re=20,000 due to lower reactivity radical formation,all that led to a deterioration of the flame ***,the integrated radical intensities of NO*,OH*,NH*,and NH_(2)*demonstrate an increasing trend as Re increased from 20,000 to 40,*** terms of thermal power,N_(2)O suffered an abrupt decrease when the thermal power increased up to 15 kW,while the opposite occurs for *** addition,the radicals intensity of OH*,NH*and NH_(2)*figures show an increase in their concentration when the thermal power increased up to 15 kW then decreased with increasing thermal intensity to reach 20 kW,reflecting into increased NO productions and decreased N_(2)O *** numerical analysis showed that Stagni,Bertolino,and Bowen Mei were the most accurate mechanisms as these give a good prediction for NO and N_(2)*** study also showed that the chemical reaction(HNO+O_(2)←→NO+HO_(2))is the main source of NO *** the chemical reaction(NH+NO←→N_(2)O+H)is responsible for the formation of N_(2)O by consuming NO and when there will

关键词： Ammonia N_(2)O NO Chemiluminescence Kinetic modeling

Preparation of crystalline Mg(OH)2 nanopowder from serpentinite mineral

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2018年第3期28卷 499-503页

作者： V. Sirota V. Selemenev M. kovaleva I. Pavlenko K. Mamunin V. Dokalov M. Yapryntsev Belgorod State National Research University Belgorod 308015 Russia Voronezh State University Voronezh 394006 Russia Belgorod State Technological University named after V.G. Shoukhov Russia

In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for Mg（OH）2 precipitation was demonstrated. In this study, crystalline Mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （Mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that Mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg（OH）2 are 30-265 nm length or width.

关键词： Serpentinite Nitric acid leaching Magnesium hydroxide Solvothermal reaction method Crystalline Mg(OH)2 nanopowder

Molecular cloning and characterization of a lipid transfer protein gene(PsLTP1) from Pinus sylvestris(L.)

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2019年第3期30卷 1149-1158页

作者： Nataliya Hrunyk Valentina.kovaleva Hryhoriy Krynytskyy Ivan Gout Francisco Amil-Ruiz Juan Munoz-Blanco Jose Luis Caballero Roman Gout Laboratory of Molecular-Genetic Markers in Woody Plants Ukrainian National Forestry UniversityGen. Chuprynka Str. 103Lviv 79057Ukraine Departamento de Bioquimica y Biologia Molecular Campus de Excelencia Internacional Agroalimentario ceiA3-Campus de RabanalesEdificio Severo Ochoa-C6Universidad de Cordoba14071 CordobaSpain Department of Structural and Molecular Biology University College LondonLondon WC1E 6BTUK

Plant nonspecific lipid transfer proteins (nsLTPs) are widely distributed through plant kingdom and are characterized by the presence of a central hydrophobic cavity, suitable for binding various hydrophobic molecules. Despite extensive research on nsLTP in different plant species, mostly angiosperm, and the great diversity of physiological processes in which they seem to be involved, their exact functions still remain unclear. Also, very limited experimental data are available on nsLTP in gymnosperm. In this study, we report for the first time on the molecular cloning of nsLTP, from Pinus sylvestris L.(PsLTP1, GenBank accession JN980402.1) and the expression pattern of PsLTP1 during ontogenesis and in response to environmental stress conditions. Total RNA from roots of 7-day old pine seedlings was used to isolate the cDNA clone, corresponding to Scots pine lipid transfer protein. The open reading frame of PsLTP1 consists of 372 bp encoding a protein of 123 amino acids. Amino acid sequence alignment revealed that mature PsLTP1 shares high level of similarity with nsLTP from other conifers and with well-studied nsLTPs from angiosperms. The PsLTP1 contains a 27-amino-acid N-terminal signal sequence and presents all the features of a plant nsLTP. Amino acid comparison analysis and 3D structure prediction showed that PsLTP1 is a type 1 nsLTP. The results of the expression analysis of Scots pine PsLTP1 gene revealed that its transcripts accumulate in actively growing tissues. Furthermore, transcription of PsLTP1 was upregulated in response to cold and salt treatments, and downregulated during acidic, osmotic and water stresses.

关键词： Scots pine Nonspecific lipid transfer protein (nsLTP) Molecular cloning Expression Abiotic stresses

Adsorption and photo-catalytic properties of layered lepidocrocite-like quasi-amorphous compounds based on modified potassium polytitanates

在线全文

学校读者我要写书评

暂无评论

Particuology 2014年第6期12卷 22-28页

作者： E.V.Tretyachenko A.V.Gorokhovsky G.Y.Yurkov F.S.Fedorov M.A.Vikulova D.S.kovaleva E.E.Orozaliev Department of Chemistry Saratov State Technical University

TiO2 compounds possess relatively high adsorption abilities and exhibit high photocatalytic activities that exhibit potential for the destruction of organic pollutants in natural and waste *** potassium polytitanates modified using transition metals and their oxides/hydroxides generate new nanomaterials that operate in the visible spectral *** study presents the synthesis and investigation of the structure,composition and photocatalytic activity of powdered nanoscale quasi-amorphous potassium polytitanates particles modified with iron,zinc,copper,cobalt and nickel sulfate in aqueous *** of the powders investigated in this work exhibit a high adsorption capacity for methylene blue dye（15-20mg/g） related to the welldeveloped surface of the layered potassium polytitanate *** transition metals and their oxides/hydroxides influences the electronic structure of the obtained systems.A high photocatalytic activity was observed for systems containing iron,zinc,nickel and their oxides/hydroxides in the ultraviolet and visible ranges.

关键词： Layered potassium titanate Chemical modification Heterostructured particles Photocatalytic activity Adsorption