检索结果-南通市图书馆

Deuterium retention in chemically vapor deposited tungsten carbide coatings and hot-rolled tungsten exposed to low-energy deuterium plasma

引用

Tungsten 2022年第1期4卷 10-19页

作者： vladimir Kh.Alimov Joachim Roth Frumkin Institute of Physical Chemistry and Electrochemistry Russian Academy of SciencesMoscow 119071Russia Max-Planck-Institut fur Plasmaphysik 85748 GarchingGermany

Samples of chemically vapor deposited(CVD)coatings of tungsten carbides W_(45)C_(55)and W_(60)C_(40)and samples of hot-rolled tungsten were exposed to deuterium(D)plasma at sample temperatures ranging from 323 to 813 K,as a result of which the samples were irradiated with D ions with an energy of about 200 eV per D particle at a flux of D particles of about1.1×10^(21)D·m^(-2)·s^(-1)to a fluence of about 2×10^(24)D·m^(-2).The concentration of deuterium in these samples was examined by the D(3 He,p)4 He nuclear *** on the measured deuterium depth profiles and assuming that these profiles are determined by diffusing D atoms,the diffusion coefficients of deuterium in the CVD tungsten carbide coatings were *** these diffusion coefficients,an estimate of the Arrhenius relation for the diffusion coefficients of deuterium in CVD tungsten carbide coatings was obtained:D=2.5×10^(-3)exp(-1.12 eV/kT)m~2·s^(-1),where T is temperature expressed in Kelvin,and k is the Boltzmann *** concentration of trapped deuterium in the bulk of CVD tungsten carbide coatings is practically independent of the stoichiometry of the *** decreases from about 5×10^(-2)to about 7×10^(-4)D/(W+C)with an increase in the deuterium plasma exposure temperature from 373 to 813 *** concentration of trapped deuterium in hot-rolled tungsten,expressed in units of the D/W atomic ratio,is more than an order of magnitude lower than the concentration of deuterium in tungsten carbides,and also decreases with increasing plasma exposure temperature.

关键词： Chemically vapor deposited tungsten carbides Tungsten Deuterium plasma Deuterium depth profiles Deuterium diffusion coefficients

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamics of Low-Viscosity Liquids Interface in an Unevenly Rotating Vertical Layer

引用

Fluid Dynamics & Materials Processing 2024年第4期20卷 693-703页

作者： Victor Kozlov vladimir Saidakov Nikolai Kozlov Laboratory of Vibrational Hydromechanics Perm State Humanitarian Pedagogical UniversityPerm614990Russia Institut de Mécanique des Fluides de Toulouse Toulouse INPToulouse31400France

The behavior of two immiscible low-viscosity liquids differing in density and viscosity in a vertical flat layer undergoing modulated rotation is experimentally *** layer has a circular axisymmetric *** the absence of modulation of the rotation speed,the interphase boundary has the shape of a short axisymmetric cylinder.A new effect has been discovered,under the influence of rotation speed modulation,the interface takes on a new dynamic equilibrium state.A more viscous liquid covers the end boundaries of the layer in the form of thin films,which have the shape of round spots of almost constant radius;with increasing amplitude of the velocity modulation,the wetting boundary *** is found that upon reaching the critical amplitude of oscillations,the film of a viscous liquid loses stability,and the outer edge of the wetting spot collapses and takes on a feathery *** is shown that this threshold is caused by the development of the Kelvin-Helmholtz oscillatory instability of the *** spreading radius of a spot of light viscous liquid and its stability are studied depending on the rotation rate,amplitude,and frequency of rotation speed *** discovered averaged effects are determined by different oscillatory interaction of fluids with the end-walls of the cell,due to different *** effect of films forming can find application in technological processes to intensify mass transfer at interphase boundaries.

关键词： Rotation oscillations immiscible fluids contact line interface film dynamic equilibrium Nomenclature frot

来源：

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

A New Mantispid-Like Species of Rhachiberothinae (Neuroptera:Berothidae) from Baltic Amber,with a Critical Review of the Fossil Record of the Subfamily

引用

Acta Geologica Sinica(English Edition) 2010年第4期84卷 655-664页

作者： vladimir N.MAKARKIN Janusz KUPRYJANOWICZ Institute of Biology and Soil Sciences Far Eastern Branch of the Russian Academy of SciencesVladivostokRussia Institute of Biology University of BialystokBialystokPoland Museum of the Earth the Polish Academy of SciencesWarsawPoland

Whalfera wiszniewskii sp. nov. is described from the Late Eocene Baltic amber. The genus Whalfera is considered as the only fossil genus confidently assigned to the Rhachiberothinae. Others previously placed in this subfamily belong to Paraberothinae （except perhaps for Oisea）. The Late Eocene/present Rhachiberothinae and the Cretaceous Paraberothinae are considered to be the subfamilies of Berothidae.

关键词： Neuroptera Berothidae Rhachiberothinae Paraberothinae Mantispidae Symphrasinae

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Search for giant pulses of radio pulsars at frequency 111 MHz with LPA radio telescope

引用

Research in Astronomy and Astrophysics 2018年第8期18卷 71-82页

作者： Andrey Nikolaevich Kazantsev vladimir Alexeevich Potapov E N.Lebedev Physical Institute of the Russian Academy of Sciences Pushchino Radio Astronomy ObservatoryPushchino 142290Russia

We have used the unique low frequency sensitivity of the Large Phased Array （LPA） radio telescope of Pushchino Radio Astronomy Observatory to collect a dataset consisting of single pulse observations of second period pulsars in the Northern Hemisphere. During observation sessions in 2011- 2017, we collected data on 71 pulsars at a frequency of 111 MHz using a digital pulsar receiver. We have discovered Giant Radio Pulses （GRPs） from pulsars B0301＋09 and B 1237＋25, and confirmed earlier reported generation of anomalously strong （probable giant） pulses from B 1133＋16 in a statistically significant dataset. Data for these pulsars and from B0950＋08 and B 1112＋50, earlier reported as pulsars generating GRPs, were analyzed to evaluate their behavior over long time intervals. It was found that the statistical criterion （power-law spectrum of GRP distribution of energy and peak flux density） seems not to be strict for pulsars with a low magnetic field at their light cylinder. Moreover, spectra of some of these pulsars demonstrate unstable behavior with time and have a complex multicomponent shape. In the dataset for B0950＋08, we have detected the strongest GRP from a pulsar with a low magnetic field at its light cylinder ever reported, having a peak flux density as strong as 16.8 kJy.

关键词： stars neutron - pulsars general - pulsars individual (PSR B0301+19 PSR B0320+39 PSR B0329+54 PSR B0809+74 PSR B0950+08 PSR B1112+50 PSR B1133+16 PSR B1237+25) - pulsars giant pulses individual pulses

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Inversion of walkaway VSP data in the presence of lateral velocity heterogeneity

引用

Energy Geoscience 2024年第2期5卷 304-313页

作者： vladimir Grechka Ilya Tsvankin Pedro Contreras CWP Department of GeophysicsColorado School of MinesGoldenCO80401USA PDVSA-INTEVEP Apartado 76343Caracas1070AVenezuela Borehole Seismic LLC USA Department of Physics ULAVenezuela

Multi-azimuth walkaway vertical seismic profiling is an established technique for the estimation of in situ slowness surfaces and inferring anisotropy ***,this technique requires the assumption of lateral homogeneity,which makes the horizontal slowness components at depths of downhole receivers equal to those measured at the *** violations of this assumption,such as lateral heterogeneity or nonzero dip of intermediate interfaces,lead to distortions in reconstructed slowness surfaces and,consequently,to errors in estimated anisotropic *** this work,we relax the assumption of lateral homogeneity and discuss how to correct vertical seismic profile data for weak lateral *** describe a procedure of downward continuation of recorded traveltimes that accounts for the presence of both vertical inhomogeneity and weak lateral heterogeneity,which produces correct slowness surfaces at depths of downhole receivers,noticing that sufficiently dense receiver coverage along a borehole is required to separate influences of vertical and lateral heterogeneity on measured traveltimes and obtain accurate estimates of the slowness *** the slowness surfaces are found and a desired type of anisotropic model to be inverted is selected,the corresponding anisotropic parameters,providing the best fit to the estimated slownesses,can be *** invert the slowness surfaces of P-waves for parameters of the simplest anisotropic model describing dipping fractures(transversely isotropic medium with a tilted symmetry axis).Five parameters of this model,namely,the P-wave velocity V0 in the direction of the symmetry axis,Thomsen's anisotropic coefficients e and d,the tilt n,and the azimuth b of the symmetry axis,can be estimated in a stable manner when maximum source offset is greater than half of receiver depth.

关键词： Walkaway vertical seismic profile Lateral velocity heterogeneity Anisotropic parameter estimation Vertical inhomogeneity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Concept of the integrative aspects of the forest ecosystem services with case study on recreation services assessment in Slovakia

引用

Ecological Processes 2014年第1期3卷 136-141页

作者： vladimir Caboun Miroslav Kovalcik Zuzana Sarvasova Department of Forest Ecology and Landscape National Forest Centre-Forest Research Institute ZvolenT.G.Masaryka 22ZvolenSK-96092Slovakia Department of Forest Policy Economics and Forest ManagementNational Forest Centre-Forest Research Institute ZvolenT.G.Masaryka 22SK-96092 ZvolenSlovakia

Introduction:This paper presents basic information on the research,classification,and application of the functions of tree species and their communities(mainly forest)in *** main aim is a scientific assessment of acquired knowledge regarding the functional effects of forests under real ecological,forest management and socio-economic conditions from various regions in Slovakia;the most up-to-date findings concerning the ecology and economics of natural resources will be applied *** second part of the paper presents methodological possibilities for valuation of outdoor recreation in *** methods and methodological approaches suitable to a valuation of recreation based on various principles and criteria(preference and non-preference methods,cost-based methods,revenue-based methods,and direct and indirect methods)are analyzed.A practical application of one indirect preference method(travel cost method)is made to evaluate outdoor recreation in forests in *** and conclusions:A new classification system and a methodology of integrative utilization of forest functions for the forest ecosystem services are *** recreation in forests,besides recreational forests and areas,assumes the character of a public good:its use by individuals has some influence on utilization by other individuals,and single users cannot be excluded from its ***,some stimulation for its production is *** principle,there are no markets for these kinds of public goods and *** total value of outdoor recreation in forests in Slovakia amounted to€163.4 million;if opportunity time costs were included,this amounted to as much as€825.7 million.

关键词： Classification of forest functions Forest functions Outdoor recreation in forests Utilization of the functions of forest tree species

来源：

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

Open-loop solution of a defender–attacker–target game:penalty function approach

引用

Journal of Control and Decision 2019年第3期6卷 166-190页

作者： vladimir Turetsky Valery Y.Glizer Department of Applied Mathematics Ort Braude College of EngineeringKarmielIsrael

A defender–attacker–target problem with non-moving target is *** problem is modelled by a pursuit-evasion zero-sum differential game with linear dynamics and quadratic cost *** this game,the pursuer is the defender,while the evader is the *** objective of the pursuer is to minimise the cost functional,while the evader has two objectives:to maximise the cost functional and to keep a given terminal state inequality *** open-loop saddle point solution of this game is obtained in the case where the transfer functions of the controllers for the defender and the attacker are of arbitrary orders.

关键词： Defender–attacker–target problem pursuit-evasion differential game zero-sum linear-quadratic game terminal state inequality constraint

来源：

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

Heterogeneity of Mantle Peridotites from the Polar Urals (Russia): Evidence from New LA-ICP-MS Data

引用

Journal of Earth Science 2019年第3期30卷 431-450页

作者： vladimir R.Shmelev Shoji Arai Akihiro Tamura Institute of Geology and Geochemistry Ural Branch Russian Academy of Sciences Yekaterinburg 620075 Russia Earth Science Department Kanazawa University Kanazawa 920-1192 Japan

To discuss the nature of the compositional heterogeneity of the peridotite massifs of the Polar Urals(Russia), the geochemical study by LA-ICP-MS of pyroxenes and amphiboles from these mantle formations was performed. The trace element compositions in clinopyroxenes indicate the existence of the mantle protolith of two types. The first protolith type, represented by lherzolites and diopside harzburgites,was originated from the partial melting(5%–10%) under the spinel facies conditions, while the second one,represented by diopside harzburgites, was formed under the polybaric partial melting(17%–19%) under garnet and spinel facies conditions. Subsequently, the mantle peridotite protolith was subject to fluidinduced partial melting in the suprasubduction setting that was resulted in the formation of *** affected by penetrating melts and fluids peridotites experienced the refertilization(LREE enrichment of clinopyroxenes) and high-temperature hydratation with subsequent development of pargasite and Mg amphibole. The high-T fluid-induced metamorphism at the subduction zone was accompanied by the formation of metaperidotites with clinochlore and REE-depleted tremolite.

关键词： pyroxene amphibole peridotite LA-ICP-MS Polar Urals Russia

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Provenance of Precambrian Fe- and Al-rich Metapelites in the Yenisey Ridge and Kuznetsk Alatau, Siberia: Geochemical Signatures

引用

Acta Geologica Sinica(English Edition) 2007年第3期81卷 409-423页

作者： Igor I. LIKHANOV vladimir V. REVERDATTO Institute of Geology and Mineralogy Siberian Branch Russian Academy of SciencesPr. Acad. Koptyuga3Novosibirsk630090Russian Federation

Major, trace and rare earth element contents of Fe- and Al-rich metapelites from the Korda （Yenisey Ridge） and Amar （Kuznetsk Alatau） formations were determined to examine the nature, origin and evolution of their protoliths. Results indicate that these rocks are the redeposited and metamorphosed products of Precambrian kaolinitic weathering crusts, while the geochemical distinctions between the studied metapelites are determined by different weathering conditions in the source area and tectonic settings. The protolith of the Korda Formation metapelites was produced by erosion products of the post-Archean granitoid rocks, which accumulated under humid climate conditions in shallow-water basins along the continental margin. The geochemical characteristics of the deeper primary deposits of the Amar Formation suggest that volcanogenic material of mafic composition derived from an island-arc environment had a major role in supplying the erosion zone. These results agree with lithofacies data and with the geodynamic reconstruction of the evolution of the Yenisey Ridge and Kuznetsk Alatau during the Mesoproterozoic and Neoproterozoic, respectively. It was shown that REEs had limited mobility during contact metamorphism. The coherent mobility of REEs during collisional metamorphism may be attributed both to mineral reactions responsible for modal changes and to local chemical heterogeneity inherited from the initial protolith.

关键词： geochemistry protolith pelitic schists Kuznetsk Alatau Yenisey Ridge Russia

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Image potential states mediated STM imaging of cobalt phthalocyanine on NaCl/Cu(100)

引用

Chinese Physics B 2016年第3期25卷 314-318页

作者：郭秦敏秦志辉黄敏 vladimir N.Mantsevich 曹更玉 State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of Sciences Faculty of Physics Moscow State University

The adsorption and electronic properties of isolated cobalt phthalocyanine （CoPc） molecule on an ultrathin layer of NaC1 have been investigated. High-resolution STM images give a detailed picture of the lowest unoccupied molecular orbital （LUMO） of an isolated CoPc. It is shown that the NaC1 ultrathin layer efficiently decouples the interaction of the molecules from the underneath metal substrate, which makes it an ideal substrate for studying the properties of single molecules. Moreover, strong dependence of the appearance of the molecules on the sample bias in the region of relatively high bias （〉 3.1 V） is ascribed to the image potential states （IPSs） of NaCI/Cu（100）, which may provide us with a possible method to fabricate quantum storage devices.

关键词： image potential states NaC1 ultrathin layer CoPc scanning tunneling microscopy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：