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Effect of a weak magnetic field on ductile-brittle transition in micro-cutting of single-crystal calcium fluoride

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Journal of Materials Science & Technology 2022年第17期112卷 96-113页

作者： Yunfa Guo Yan Jin Lee Yu Zhang Anastassia Sorkin sergei Manzhos Hao Wang Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1Singapore 117575Singapore School of Materials and Chemical Technology Tokyo Institute of TechnologyOokayama 2-12-1Meguro-kuTokyo 152-8552Japan

Magneto-plasticity occurs when a weak magnetic field alters material plasticity and offers a viable solution to enhance ductile-mode cutting of brittle *** study demonstrates the susceptibility of non-magnetic single-crystal calcium fluoride(CaF_(2))to the magneto-plastic *** influence of magneto-plasticity on CaF_(2) was confirmed in micro-deformation tests under a weak magnetic field of 20 *** surface pile-up effect was weakened by 10-15 nm along with an enlarged plastic zone and suppressed crack propagation under the influence of the magnetic ***-cutting tests along different crystal orientations on the(111)plane of CaF_(2) revealed an increase in the ductile-brittle transition of the machined surface with the aid of magneto-plasticity where the largest increase in ductile-brittle transition occurred along the[112]orientation from 512 nm to a range of 664-806 ***,the subsurface damage layer was concurrently thinner under magnetic *** anisotropic influence of the magnetic field relative to the single-crystal orientation and the cutting direction was also *** analytical model was derived to determine an orientation factor M that successfully describes the anisotropy while considering the single-crystal dislocation behaviour,material fracture toughness,and the orientation of the magnetic *** suggested theoretical mechanism of magneto-plasticity via formation of non-singlet electronic states in defected configurations was confirmed with density functional theory *** successful findings on the influence of a weak magnetic field on plasticity present an opportunity for the adoption of magnetic-assisted micro-cutting of non-magnetic materials.

关键词： Magneto-plasticity Weak magnetic field Brittle material Ductile-brittle transition Micro-cutting

A bridge for accelerating materials by design

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npj Computational Materials 2015年第1期1卷 56-66页

作者： Bobby G Sumpter Rama K Vasudevan Thomas Potok sergei V Kalinin Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTNUSA Computer Science and Mathematics Division Oak Ridge National LaboratoryOak RidgeTNUSA Institute for Functional Imaging of Materials Oak Ridge National LaboratoryOak RidgeTNUSA Computer Science and Engineering Division Oak Ridge National LaboratoryOak RidgeTNUSA

Recent technical advances in the area of nanoscale imaging,spectroscopy and scattering/diffraction have led to unprecedented capabilities for investigating materials structural,dynamical and functional *** addition,recent advances in computational algorithms and computer capacities that are orders of magnitude larger/faster have enabled large-scale simulations of materials properties starting with nothing but the identity of the atomic species and the basic principles of quantum and statistical mechanics and *** with these advances,an explosion of high-resolution data has *** confluence of capabilities and rise of big data offer grand opportunities for advancing materials sciences but also introduce several *** this perspective,we identify challenges impeding progress towards advancing materials by design(e.g.,the design/discovery of materials with improved properties/performance),possible solutions and provide examples of scientific issues that can be addressed using a tightly integrated approach where theory and experiments are linked through big-deep data.

关键词： bridge starting materials

Alpine ecotone in the Siberian Mountains:vegetation response to warming

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Journal of Mountain Science 2021年第12期18卷 3099-3108页

作者： KHARUK Viacheslav I. IM sergei T. PETROV Il’ya A. Sukachev Institute of Forest Federal Scientific CenterRussian Academy of ScienceSiberian BranchAcademgorodok 50/28Krasnoyarsk 660036Russia Siberian Federal University Svobodny str.79Krasnoyarsk 660041Russia Reshetnev Siberian State University of Science and Technology Krasnoyarsky rabochy str.31Krasnoyarsk 660014Russia

Birch(Betula tortuosa)is one of the treeline forming species within the Siberian *** analysed the area dynamics of birch stands and the upslope climb of birch treeline based on the Landsat time series scenes and on-ground *** found that since the warming onset(1970th)birch area increased by 10%,birch stands and treeline boundary were moving upslope with a rate of 1.4 m/yr and 4.0 m/*** upslope shift correlated with air temperatures at the beginning(May-June)and the end(August-October)of the growth ***,no correlation was found between birch upslope migration and *** negatively influenced both birch area growth and birch upslope climb during spring,fall,and *** the windy habitats,birch,together with larch and Siberian pine,formed clusters(hedges)which mitigated the influence of adverse *** clusters are the adaptive pattern for trees’upslope climb within windward *** other adaptation to the harsh alpine ecotone habitat is non-leaf(bark)photosynthesis which supports tree ***,Betula tortuosa upslope climb depends on the wind impact and warming in spring and fall that extended growth *** ongoing warming and observed wind speed decrease on the background of sufficient precipitation,it is expected to further birch advance into alpine tundra in the Siberian Mountains.

关键词： Alpine biomes Treeline shift rate Treeline ecotone Siberian mountain forests Betula tortuosa Forest densification Tree clustering

Siberian silkmoth outbreaks surpassed geoclimatic barrier in Siberian Mountains

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Journal of Mountain Science 2020年第8期17卷 1891-1900页

作者： KHARUK Viacheslav I. IM sergei T. SOLDATOV Vladimir V. Sukachev Institute of Forest Federal Scientific CenterRussian Academy of ScienceSiberian BranchAcademgorodok 50/28Krasnoyarsk660036 Russia Siberian Federal University Svobodny str.79Krasnoyarsk660041 Russia Reshetnev Siberian State University of Science and Technology Krasnoyarsky rabochy str.31Krasnoyarsk660014 Russia Russian Center of Forest Protection Academgorodok 50A/2Krasnoyarsk660036 Russia

Siberian silkmoth(SSM,Dendrolimus sibiricus Tschetv.)is the most important defoliator of Siberian pine(Pinus sibirica Du Tour)and fir(Abies sibirica Ledeb.)***-induced SSM outbreaks are one of the major driving factors of successions within the taiga *** is suggested that climate change impacted the SSM range and life *** analyzed the migration of alpine and northerly SSM outbreak boundaries in Siberia and the impact of the climate variables and topography on the outbreak *** used time-series scenes(multispectral data,and vegetation indexes EVI and NDII)in combination with field studies,climate variables,and GIS *** found that SSM outbreaks in the area of alpine boundary shifted about 370 m uphill since the mid of *** outbreak onset was promoted by increased dryness and active temperatures and decreased root zone moisture content in the spring-early summer *** terrain topography strongly affected SSM outbreak onset and ***,the outbreak was located at the middle elevations on the gentle concave southeastern slopes,which are the favorable insect habitats between *** the outbreak expanded uphill and downhill,to steeper slopes,and both concave and convex *** with elevation range expansion,SSM surpassed its northern historical outbreak boundary:the potential outbreaks’boundary moved about 300 km *** warming contributes to SSM migration into former outbreak free conifer stands located in highlands and at northern latitudes.

关键词： Insect outbreaks Remote sensing monitoring Insect ranges expansion Siberian silkmoth Forest health Conifer mortality

Temperature monitoring from 2012 to 2019 in central part of Suntar-Khayat Ridge,Russia

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Journal of Mountain Science 2020年第10期17卷 2321-2338页

作者： Robert SYSOLYATIN sergei SERIKOV Mikhai Yana TIKHONRAVOVA Vladimir ZHIZHIN Maria ROJINA Melnikov Permafrost Institute Yakutsk 677010Russia

In recent decades,research of the Alps,Qinghai-Tibet Plateau,and Cordillera have made great progress in understanding the phenomenon of *** the most part,this has been made possible due to temperature ***,the permafrost parameters in an area of more than 2 million square km of the mountainous regions of northeast Asia,for the most part,remain a blank spot in the scientific *** to the lack and insufficiency of factual materials,in 2012 the *** Permafrost Institute began to take temperature measurements in the upper part of the permafrost in the central part of the VerkhoyanKolyma uplands,namely the Suntar-Khayat *** article describes the temperature characteristics of air,surface and rocks of the active layer in the range of heights from 850 to 1821 m,in various landscape and topographic *** the observation period from 2012 to 2019,we obtained information on temperatures in the soils of the active layer at depths of 1 m,3 m,4 m,and 5 m and also air and surface temperature *** availability of data on automated monitoring of rock temperatures in the active layer and the upper horizons of the layer of annual heat rotations made it possible to substantiate the most typical conditions of the temperature conditions of the permafrost zone of the characterized *** parameters of permafrost existence and development are in favorable *** is shown in the analysis of temperature data of air,surface and active *** temperatures in the active layer of annual heat rotations are most clearly represented at a depth of 1 ***,on the territory of the mountain regions of Eastern Siberia,there are no more such sites for monitoring the temperature regime of *** on the permafrost parameters in the region will allow us to begin the process of creating new models or checking existing forecasts and the distribution of the temperature *** will also make it possible to eval

关键词： Air temperature Ground temperature Climate change Mountain permafrost Active layer thickness

Post-Late Paleozoic Collisional Framework of Southern Great Altai

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Acta Geologica Sinica(English Edition) 2012年第5期86卷 1093-1104页

作者： Boris M. CHIKOV sergei V. ZINOVIEV Еugene V. DEYEV Institute of Geology Siberian Branch of Russian Academy of Sciences Novosibirsk 630090 Russia

We outline the post-Late Paleozoic （latest Permian to Cenozoic） collisional framework of the southern Great Altai （Central Asia） produced by the convergence between the Tuva-Mongolia and Junggar continental terranes （microplates）. The collisional structures in the region classified on the basis of their geometry and deformation style, dynamic metamorphism, and compositions of tectonites are of three main types：（1） mosaic terranes made up of large weakly deformed Paleozoic blocks separated by younger shear zones; （2） contractional deformation systems involving structures formed in post-Late Paleozoic time, parallel faults oriented along collisional deformation systems, and relict lenses of Paleozoic orogenic complexes; and （3） isolated zones of dynamic metamorphism composed mostly of collisional tectonites different in composition and alteration grade.

关键词： continental collision post-Late Paleozoic events tectonic framework dynamic metamorphism Altai Central Asia

A new tectonic model for the Itmurundy Zone,central Kazakhstan:linking ocean plate stratigraphy,timing of accretion and subduction polarity

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Geoscience Frontiers 2024年第4期15卷 245-273页

作者： Inna Safonova Ilya Savinskiy Alina Perfilova Olga Obut Alexandra Gurova sergei Krivonogov Southwest Jiaotong University Xi’an Road 999ChengduChina Sobolev Institute of Geology and Mineralogy SB RASKoptyuga Ave.3NovosibirskRussia Novosibirsk State University Pirogova St.2NovosibirskRussia Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Koptyuga Ave.3NovosibirskRussia

The Itmurundy Zone of Central Kazakhstan is a key structure in the core of the Kazakh Orocline representing a typical Pacific-type orogenic belt hosting accretionary complex,ophiolite massifs and serpentinite mé*** main controversies in the existing tectonic models of the Itmurundy Zone are about the timing of subduction and accretion,the direction and kinematics of subduction and the number of oceanic plates.A new model for the early Paleozoic tectonic story of the Itmurundy Zone is postulated in this paper,based on new detailed geological and U-Pb detrital zircon age data,combined with previously documented geological,U-Pb age,microfossil,geochemical and isotope data from igneous rocks,deep-sea sediments and greywacke *** present study employs the Ocean Plate Stratigraphy(OPS)model to explain the tectonic processes involved in the evolution of the Itmurundy Zone and to pre-sent a holistic story of Ordovician oceanic plate(s),which accretion formed an accretionary *** detailed mapping allows distinguishing three types of OPS assemblages:(1)Chert-dominated,(2)OIB-hosting,and(3)*** U-Pb ages of detrital zircons from sandstones of OIB and Chert types show unimodal distributions with similar main peaks of magmatism at 460-455 Ma in the provenance,and their maximum depositional ages(MDA)span 455-433 *** samples from OPS Type 3 show the peaks of magmatism both at ca.460 Ma and the MDA of 452 Ma and 459 Ma,*** MDA of sandstones and microfossils data from chert show the younging of strata to the south and SE in Types 1 and 2 and to NEE for Type 3(in present coordinates)suggesting double-sided subduction to the NNW and SEE and,accordingly,the co-existence of pieces of two oceanic plates in Ordovician *** U-Pb zircon data from both igneous and clastic rocks indicate a period of subduction erosion in early Ordovician *** a whole,the accreted OPS units of the Itmurundy Zone record the timing of subduction and accre

关键词： Central Asian Orogenic Belt Accretionary complex Magmatic rocks Sedimentary rocks Subduction polarity Lithospheric plates

A special issue “Planning, modelling and operation of modern power systems” of Global Energy Interconnection Journal

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Global Energy Interconnection 2022年第5期5卷 I0002-I0005页

作者： Valery Stennikov sergei Podkovalnikov 不详

Modern power systems(PSs)are among the most globally widespread technical systems in terms of both territorial scale and the level of involvement in various spheres of human *** is primarily because electrical energy is a universal energy carrier that has multiple applications,including industrial production,transport(particularly,charging of electric vehicles),agriculture,information and communication,residential-commercial sector,and cultural sphere.

关键词： globally operation involvement

From interconnections of local electric power systems to Global Energy Interconnection

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Global Energy Interconnection 2018年第1期1卷 4-10页

作者： Nikolai Voropai sergei Podkovalnikov Kirill Osintsev Melentiev Energy Systems Institute SB RAS National Research University 'Moscow Power Institute'

The interconnections of electric power systems are developed for the economic benefits and in order to increase the overall power supply reliability and quality level. Development of power industry shows the positive effects in operation of the country-wide electric power systems and international interconnections. Creation of World Energy System or, by the other words, Global Energy Interconnection is objective trend on the way of expansion of international and intercontinental electric power interconnections. Several important aspects of above mentioned problems are discussed in this paper.

关键词： Electric Power Systems Power Interconnections Global Energy Interconnection