检索结果-南通市图书馆

Deep learning ferroelectric polarization distributions from STEM data via with and without atom finding

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1342-1352页

作者： Christopher T.Nelson Ayana Ghosh Mark Oxley Xiaohang Zhang Maxim Ziatdinov Ichiro Takeuchi sergei V.Kalinin Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTNUSA Computational Sciences and Engineering Division Oak Ridge National LaboratoryOak RidgeTNUSA Department of Materials Science and Engineering University of MarylandCollege ParkMDUSA

Over the last decade,scanning transmission electron microscopy(STEM)has emerged as a powerful tool for probing atomic structures of complex materials with picometer precision,opening the pathway toward exploring ferroelectric,ferroelastic,and chemical phenomena on the atomic *** to date extracting a polarization signal from lattice coupled distortions in STEM imaging rely on discovery of atomic positions from intensity maxima/minima and subsequent calculation of polarization and other order parameter fields from the atomic ***,we explore the feasibility of polarization mapping directly from the analysis of STEM images using deep convolutional neural networks(DCNNs).In this approach,the DCNN is trained on the labeled part of the image(i.e.,for human labelling),and the trained network is subsequently applied to other *** explore the effects of the choice of the descriptors(centered on atomic columns and grid-based),the effects of observational bias,and whether the network trained on one composition can be applied to a different *** analysis demonstrates the tremendous potential of the DCNN for the analysis of high-resolution STEM imaging and spectral data and highlights the associated limitations.

关键词： Deep network ferroelectric

Enhanced strength-ductility synergy in a wire and arc additively manufactured Mg alloy via tuning interlayer dwell time

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第12期11卷 4696-4709页

作者： Dong Ma Chunjie Xu Shang Sui Jun Tian Can Guo Xiangquan Wu Zhongming Zhang Dan Shechtman sergei Remennik School of Materials Science and Engineering Xi’an University of TechnologyXi’anShaanxi 710048China Xi’an Shechtman Nobel Prize New Materials Institute Xi’an 710048China Xi’an Key Laboratory of Advanced Magnesium Alloy Additive Manufacturing and Precision Forming Xi’anShaanxi 710048China Department of Materials Science and Engineering Technion-Israel Institute of TechnologyHaifa 32000Israel Center for Nanoscience&Nanotechnology Hebrew University of JerusalemEdmond J.Safra CampusJerusalem 91904Israel MGM Nobel Prize New Materials Co. LtdTongchuan 727100China

Strength-ductility trade-off is a common issue in Mg alloys. This work proposed that a synergistic enhancement of strength and ductility could be achieved through tuning interlayer dwell time(IDT) in the wire and arc additive manufacturing(WAAM) process of Mg *** thermal couples were used to monitor the thermal history during the WAAM process. Additionally, the effect of different IDTs on the microstructure characteristics and resultant mechanical properties of WAAM-processed Mg alloy thin-wall were investigated. The results showed that the stable temperature of the thin-wall component could reach 290 ℃ at IDT=0s, indicating that the thermal accumulation effect was remarkable. Consequently, unimodal coarse grains with an average size of 39.6 μm were generated, and the resultant room-temperature tensile property was poor. With the IDT extended to 60s, the thermal input and thermal dissipation reached a balance, and the stable temperature was only 170 ℃, closing to the initial temperature of the substrate. A refined grain structure with bimodal size distribution was obtained. The remelting zone had fine grains with the size of 15.2 μm, while the arc zone owned coarse grains with the size of 24.5 μ*** alternatively distributed coarse and fine grains lead to the elimination of strength-ductility trade-off. The ultimate tensile strength and elongation of the samples at IDT=60s are increased by 20.6 and 75.0% of those samples at IDT=0s, respectively. The findings will facilitate the development of additive manufacturing processes for advanced Mg alloys.

关键词： Wire arc additive manufacturing Interlayer dwell time Strength-ductility Magnesium alloys

Probing atomic-scale symmetry breaking by rotationally invariant machine learning of multidimensional electron scattering

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

npj Computational Materials 2021年第1期7卷 595-600页

作者： Mark P.Oxley Maxim Ziatdinov Ondrej Dyck Andrew R.Lupini Rama Vasudevan sergei V.Kalinin Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTNUSA Computational Sciences and Engineering Division Oak Ridge National LaboratoryOak RidgeTNUSA

The 4D scanning transmission electron microscopy(STEM)method maps the structure and functionality of solids on the atomic scale,yielding information-rich data sets describing the interatomic electric and magnetic fields,structural and electronic order parameters,and other symmetry breaking distortions.A critical bottleneck is the dearth of analytical tools that can reduce complex 4D-STEM data to physically relevant *** propose an approach for the systematic exploration of 4D-STEM data using rotationally invariant variational autoencoders(rrVAE),which disentangle the general rotation of the object from other latent *** implementation of purely rotational rrVAE is discussed as are applications to simulated data for graphene and zincblende *** rrVAE analysis of experimental 4D-STEM data of defects in graphene is illustrated and compared to the classical center-of-mass *** approach is universal for probing symmetry-breaking phenomena in complex systems and can be implemented for a broad range of diffraction methods.

关键词： symmetry breaking rotational

Observation of nonlinear fractal higher order topological insulator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第11期13卷 2699-2714页

作者： Hua Zhong Victor O.Kompanets Yiqi Zhang Yaroslav V.Kartashov Meng Cao Yongdong Li sergei A.Zhuravitskii Nikolay N.Skryabin Ivan V.Dyakonov Alexander A.Kalinkin sergei P.Kulik Sergey V.Chekalin Victor N.Zadkov Key Laboratory for Physical Electronics and Devices Ministry of EducationSchool of Electronic Science and EngineeringXi’an Jiaotong University710049 Xi’anChina Institute of Spectroscopy Russian Academy of SciencesTroitskMoscow 108840Russia Quantum Technology Centre Faculty of PhysicsM.V.Lomonosov Moscow State UniversityMoscow 119991Russia Faculty of Physics Higher School of EconomicsMoscow 105066Russia

Higher-order topological insulators(HOTIs)are unique materials hosting topologically protected states,whose dimensionality is at least by 2 lower than that of the *** states in such insulators may be strongly confined in their corners which leads to considerable enhancement of nonlinear processes involving such ***,all nonlinear HOTIs demonstrated so far were built on periodic bulk lattice ***,we demonstrate the first nonlinear photonic HOTI with the fractal *** their fractional effective dimensionality,the HOTIs constructed here on two different types of the Sierpiński gasket waveguide arrays,may support topological corner states for unexpectedly wide range of coupling strengths,even in parameter regions where conventional HOTIs become *** demonstrate thresholdless spatial solitons bifurcating from corner states in nonlinear fractal HOTIs and show that their localization can be efficiently controlled by the input beam *** observe sharp differences in nonlinear light localization on outer and multiple inner corners and edges representative for these fractal *** findings not only represent a new paradigm for nonlinear topological insulators,but also open new avenues for potential applications of fractal materials to control the light flow.

关键词： materials. flow. topological

The Problem of Text and ＂Personality Context＂： Intercultural Approach （Oriental Dimension）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Philosophy Study 2014年第3期4卷 224-231页

作者： sergei Lepekhov Siberian Branch of the Russian Academy of Sciences

One of the central problems of society and a civilization was always the ratio of personality and common culture. One of these aspects is a hermeneutic problem of understanding and interpretation of the text, or as one of options, --a ratio of the text and a personal context. There are both generality and distinctions in approaches of various cultures to this problem. There are many parallels that can be drawn between the directions and results of the investigation of the European and Buddhist hermeneutic traditions. The European hermeneutics on the whole is known to be based on the presumption of the unique personal authorship of a text, a multitude of historical viewpoints and meanings. Thus, the problem of understanding and interpretation acts as a problem of combining differences. The mechanism of conveying the cultural traditions under such conditions inevitably turns into a mechanism of interpreting the message conveying a definite cultural meaning. Modifying the meaning of any message is supposed to be dictated by the very fact of the temporal distance between the moments of creating and reading the text. In a number of oriental cultures, we face a somewhat different understanding of the problems of authorship, communication, ontology, and existence and on the whole, with a different understanding of the very problem of understanding. Just like we admit that it is necessary to preserve all existing natural landscapes, in the cultural life, we must consider every existing culture and their bearers--ethnic groups self-valuable and necessary.

关键词： comparative analysis of European and Buddhist hermeneutics "behavioral" and "existential"commentary on the text cultural tolerance

Problem of Nuclear Decay by Proton Emission in Fully Quantum Consideration: Calculations of Penetrability and Role of Boundary Conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Physics 2011年第6期2卷 572-585页

作者： sergei P Maydanyuk sergei V Belchikov 不详

We develop a new fully quantum method for determination of widths for nuclear decay by proton emission where multiple internal reflections of wave packet describing tunneling process inside proton-nucleus radial barrier are taken into account. Exact solutions for amplitudes of wave function, penetrability T and reflection R (estimated for the first time for decay problem) are found for n -step barrier (at arbitrary n) which approximates the realistic barrier. In contrast to semiclassical approach and two-potential approach, we establish by this method essential dependence of the penetrability on the starting point Rform in the internal well where proton starts to move outside (for example, for Ta the penetrability is changed up to 200 times;accuracy is T+R-1|-15 ). We impose a new condition: in the beginning of the proton decay the proton starts to move outside from minimum of the well. Such a condition provides minimal calculated half-life and gives stable basis for predictions. However, the half-lives calculated by such an approach turn out to be a little closer to experimental data in comparison with the semiclassical half-lives. Estimated influence of the external barrier region is up to 1.5 times for changed penetrability.

关键词： Tunneling Multiple Internal Reflections Wave Packet Decay by Proton Emission Penetrability and Reflection Half-Life

The evolution of interstate power grid formation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Global Energy Interconnection 2021年第4期4卷 335-353页

作者： Nikolai Voropai sergei Podkovalnikov Lyudmila Chudinova Melentiev Energy Systems Institute of Siberian Branch of the Russian Academy of Sciences 130Lermontov Str.Irkutsk 664033Russia

This study analyzes the process of electric power system integration in various regions *** process is implemented by creating both interstate electric ties and power *** analysis is comprehensive and examines the system,spatial,technical,organizational,and market aspects of the *** countries,including developed countries such as Europe and North America,as well as economically developing countries such as Central America and Africa,are involved in this ***,the rates and scales of electric power integration differ across various regions *** analysis shows that the process of electric power integration,which has decades of history,is still ongoing,despite the growth of other trends,such as the development of distributed *** electricity integration is expected to lead to the formation of a global power interconnection in the long term.

关键词： Interstate electric power grids/interconnections Interstate electric ties

The Siberian Craton and its evolution in terms of the Rodinia hypothesis

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

Episodes 2006年第3期29卷 169-174页

作者： Dmitry Gladkochub sergei Pisarevsky Tatiana Donskaya Lev Natapov Anatoliy Mazukabzov Arkadiy Stanevich Eugene Sklyarov Institute of the Earth＇s Crust Siberian Branch Russian Academy of Science Lermontov Ave. 128 664033 Irkutsk Russia Tectonics Special Research Centre School of Earth and Geographical Sciences The University of Western Australia 35 Stirling Highway Crawley WA 6009 Australia GEMOS ARC Key Centre Department of Earth and Planetary Sciences Macquarie University Sydney NSW 2109 Australia

Recent geochronological studies in southern Siberia support a Siberian assembly between 2.1 and 1.8 Ga. This broadly coincides with major orogenic events in most other Precambrian continents including Laurentia. In the Mesoproterozoic, Siberia was mainly an area of stable platform sedimentation whereas Laurentia underwent a continental growth from southeast. Lack of traces of the Grenville orogeny in Siberia suggests its peripheral position in Rodinia. The eastern （Uchur- Maya area） and western （Yenisei area） Siberian margins probably faced oceans during the Meso- and Neoproterozoic. Recent geological, geochronological, geochemical and paleomagnetic data suggest integrity of Siberia and Laurentia in the Meso- and early Neoproterozoic with the Siberian southern margin close to the northern margin of Laurentia. However, some ‘intervening＇ continental blocks were probably located between these two cratons. The 750-720 Ma igneous event was probably related to the rifting between Siberia and Laurentia and the opening of the Paleo-Asian Ocean, causing the development of a passive margin sedimentary succession in southern Siberia.

关键词：西伯利亚地质年代学切向压缩力前寒武纪沉降

Annual report of IGCP Project No.440 in 2003——Rodinia assembly and breakup

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscientific Research in Northeast Asia 2004年第1期7卷 8-14页

作者： sergei Pisarevsky Tectonic Special Research Centre University of Western Australia Crawlay WA6009 Australia

With the latest information on geology, isotop chronology, geochemistry and aerial geophysics, the structural enviroment, geological event characterists and evolution history of component units of Rodinia Supercontinent on a global scale are discussed. And some neo views and genetic pattern are provided. The East Eurppean Craton had a complex evolution history between 1.7 and 0.9 Ga. The arthors propose a new reconstruction of Laurentia acient land and Siberia at ca. 1 050～1 000 Ma. The largest litho-structural record of the Meso-Neoproterozoic orogenic collage in South America made up the western border of the South American Platform African Cratons are the result of convergence of Paleoproterozoic/Archaem Cratonic blocks. A part of Eastern Antarctica attached to southern Africa in Mesoproterozoic. Neoproterozoic felsic magmatic events in New India made the western border of Rodinia Pre-Grevoillian Laurentia was established as a major continental block by the end of the Paleoproterozoic. South China is geologically plausible to be between southern Laurentia and eastern Australia. Yangzi-Tarim connection or neighborhood is proposed. According to the abovementionded, the assembly and breakup paattern of Rodinia proposed by Pisarevsky is tested. It telles that primary break up is along the western border of Laurentia ancient land, which is similar to northern Atlantic. Another characteristic is that some continents are not considered as component parts of Rodinia, eg. India, Congo and San-Francisco.

关键词： Rodinia Supercontinent Laurentia ancient land assembly and break up pattern