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Slice Thickness Optimization for the Focused Ion Beam-Scanning Electron Microscopy 3D Tomography of Hierarchical Nanoporous Gold

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Nanomanufacturing and Metrology 2022年第2期5卷 112-118页

作者： alexander Shkurmanov Tobias Krekeler Martin Ritter Electron Microscopy Unit Hamburg University of Technology(TUHH)Eißendorfer Straße 4221073HamburgGermany

The combination of focused ion beam (FIB) with scanning electron microscopy (SEM), also known as FIB-SEM tomography, has become a powerful 3D imaging technique at the nanometer scale. This method uses an ion beam to mill away a thin slice of material, which is then block-face imaged using an electron beam. With consecutive slicing along the z-axis and subsequent imaging, a volume of interest can be reconstructed from the images and further analyzed. Hierarchical nanoporous gold (HNPG) exhibits unique structural properties and has a ligament size of 15–110 nm and pore size of 5–20 nm. Accurate reconstruction of its image is crucial in determining its mechanical and other properties. Slice thickness is one of the most critical and uncertain parameters in FIB-SEM tomography. For HNPG, the slice thickness should be at least half as thin as the pore size and, in our approach, should not exceed 10 nm. Variations in slice thickness are caused by various microscope and sample parameters, e.g., converged ion milling beam shape, charging effects, beam drift, or sample surface roughness. Determining and optimizing the actual slice thickness variation appear challenging. In this work, we examine the influence of ion beam scan resolution and the dwell time on the mean and standard deviation of slice thickness. After optimizing the resolution and dwell time to achieve the target slice thickness and lowest possible standard deviation, we apply these parameters to analyze an actual HNPG sample. Our approach can determine the thickness of each slice along the z-axis and estimate the deviation of the milling process along the y-axis (slow imaging axis). For this function, we create a multi-ruler structure integrated with the HNPG sample.

关键词： Focused ion beam Scanning electron microscopy Tomography Hierarchical nanoporous gold

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Coexisting charge density wave and ferromagnetic instabilities in monolayer InSe

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npj Computational Materials 2022年第1期8卷 1101-1109页

作者： Evgeny A.Stepanov Viktor Harkov Malte Rösner alexander I.Lichtenstein Mikhail I.Katsnelson alexander N.Rudenko CPHT CNRSEcole PolytechniqueInstitut Polytechnique de ParisF-91128PalaiseauFrance I.Institute of Theoretical Physics University of HamburgNotkestraße 922607HamburgGermany European X-Ray Free-Electron Laser Facility Holzkoppel 422869SchenefeldGermany Radboud University Institute for Molecules and Materials6525AJNijmegenThe Netherlands The Hamburg Centre for Ultrafast Imaging Luruper Chaussee 14922761HamburgGermany

Recently fabricated InSe monolayers exhibit remarkable characteristics that indicate the potential of this material to host a number of many-body *** this work,we systematically describe collective electronic effects in hole-doped InSe monolayers using advanced many-body *** this end,we derive a realistic electronic-structure model from first principles that takes into account the most important characteristics of this material,including a flat band with prominent van Hove singularities in the electronic spectrum,strong electron–phonon coupling,and weakly screened long-ranged Coulomb *** calculate the temperature-dependent phase diagram as a function of band filling and observe that this system is in a regime with coexisting charge density wave and ferromagnetic instabilities that are driven by strong electronic Coulomb *** regime can be achieved at realistic doping levels and high enough temperatures,and can be verified *** find that the electron–phonon interaction does not play a crucial role in these effects,effectively suppressing the local Coulomb interaction without changing the qualitative physical picture.

关键词： ferromagnetic charge wave

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Structure and heterogeneity of habitat determine diet of predators despite prey abundance:Similar response in Long-eared,Short-eared Owls and Common Kestrels

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Avian Research 2023年第1期14卷 54-61页

作者： Tatyana Kovinka alexander Sharikov Tatyana Massalskaya Sergey Volkov Zoology and Ecology Department Moscow State Pedagogical UniversityKibalchicha Str.6-3129164MoscowRussid Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscow119071Russia

According to one of the theses of optimal foraging theory,main prey species abundance in the hunting area is the main factor determining the diet and habitat choices of birds of *** other factors can also be *** habitat structure influences the predators’diets as *** this study we examined the influence of habitat structure on diet compositions of three species of birds:Long-eared Owl(Asio otus),Short-eared Owl(***)and Common Kestrel(Falco tinnunculus).The study was carried out from 2007 to 2019 in a 48 km2area of the Crane’s Homeland Reserve,Moscow Region,*** habitat structures of model species’hunting territories(ratio of different types of landscape elements)were classified in module"Semi-Automatic Classification Plugin"based on the QGIS.A boosted regression tree analysis identified that the share of the main prey species in the diet is primarily determined by the landscape structure of hunting *** largest share of Common Vole(Microtus arvalis)in birds’diet was determined by the shrubs area(15%of hunting area),the meadow area(75%),the habitat heterogeneity(70%)and the arable land area(5%).The same predictors determined the largest share of Root Vole(Microtus oeconomus):the shrubs area 25%,the meadow area 70%,and the arable land area 3%.The annual mean abundance of prey species did not determine their importance in the diet of birds of ***,the main prey abundance in the hunting area is not a determining factor for the formation of diet composition of birds of prey.

关键词： Birds of prey diet Boosted regresion tnee Habitat strnocture efiect Prey sbundance

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Eastern Siberia permafrost transect(ESPT).A first stage:The Verkhoyansk Range part

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Journal of Mountain Science 2023年第6期20卷 1499-1507页

作者： Robert SYSOLYATIN Svetlana KALINICHEVA alexander FEDOROV Maria ROZHINA Melnikov Permafrost Institute Yakutsk 677010Russia

Environmental and geomorphological processes in the mountainous areas of Eastern Siberia is strongly conditioned by the thermal state of permafrost(permanently frozen ground).However,the scarce data about climate and weak of permafrost study have led to the unclarity of mountain permafrost condition in this *** increase in the mean annual air temperature over the past 50 years in the northeastern Siberia by various estimates is from 1.1℃to 3.3℃.So far,almost no information is available on the permafrost response to climatic changes in the *** Kolyma Route(around 2000 km length),connecting Yakutsk and Magadan that crosses 5 climatic types and more than 10 permafrost landscapes,so it seems a suitable path for establishing basic(reference)monitoring *** 12 target boreholes,on the first stage 5 boreholes up to 30 m in depth were drilled and instrumented for measuring temperature at sites adjacent to weather stations in the Verkhoyansk Range from 283 to 1288 m *** we present conception,purpose,and methods for permafrost study project with first preliminary results from the highest weather station of the East Siberia *** following research about geophysical investigations,permafrost landscape description,mapping and spatial modelling,numerical computing,physical modelling of permafrost thickness might be initiated by the Eastern Siberia Permafrost Transect(ESPT)-project.

关键词： Ground temperature Mountain permafrost Temperature e monitoring Verkhoyansk Range Climate change.

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Grazing rate and feeding selectivity of small and large bodied cladocerans in waters from lakes with different salinity and phytoplankton structure

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Journal of Oceanology and Limnology 2023年第4期41卷 1341-1351页

作者： Egor ZADEREEV Tatiana LOPATINA Svyatoslav OVCHINNIKOV alexander TOLOMEEV Institute of Biophysics Krasnoyarsk Research CenterSiberian Branch of Russian Academy of SciencesAkademgorodokKrasnoyarsk 660036Russia Siberian Federal University Krasnoyarsk 660041Russia

Cladocera are filter feeders abundant in freshwaters,which consume phytoplankton particles in wide size and taxonomic *** ability of cladocerans to control phytoplankton abundance by grazing is determined by various factors including the characteristics of *** salinization may reduce the strength of top-down grazing control of phytoplankton because of the detrimental effects of salinity on the grazing intensity of *** performed grazing experiments with two species of Cladocera of different body lengths to test their ability to graze on phytoplankton in natural waters differing in salinity and size and taxonomic composition of food *** experiments demonstrated that the grazing rate was mostly controlled by the abundance of phytoplankton in the *** grazing rate was reduced at salinity *** 3 g/L of NaCl in the *** lower grazing rate was observed in the medium with larger phytoplankton *** species predominantly consumed phytoplankton particles with a diameter of 6-12μm,which may shift the size distribution of phytoplankton towards a larger average diameter of *** taxon-specific feeding was also observed,as both species predominantly consumed diatom ***,we found that because of grazing,the size and taxonomic characteristics of phytoplankton are shifted towards a less edible *** detrimental effect of elevated salinity on grazing rate supports growing concern about freshwater salinization negatively affecting water quality,particularly reducing top-down grazing control of phytoplankton.

关键词： selective feeding Daphnia Moina top-down control phytoplankton salinity

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Magnetic Moment Tensor Potentials for collinear spin-polarized materials reproduce different magnetic states of bcc Fe

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npj Computational Materials 2022年第1期8卷 107-112页

作者： Ivan Novikov Blazej Grabowski Fritz Körmann alexander Shapeev Skolkovo Institute of Science and Technology Skolkovo Innovation CenterNobel St.3Moscow143026Russia Institute for Materials Science University of StuttgartPfaffenwaldring 5570569StuttgartGermany Computational Materials Design Max-Planck-Institut für Eisenforschung GmbHD-40237DüsseldorfGermany Materials Science and Engineering Delft University of Technology2628 CDDelftThe Netherlands

We present the magnetic Moment Tensor Potentials(mMTPs),a class of machine-learning interatomic potentials,accurately reproducing both vibrational and magnetic degrees of freedom as provided,e.g.,from first-principles *** accuracy is achieved by a two-step minimization scheme that coarse-grains the atomic and the spin *** performance of the mMTPs is demonstrated for the prototype magnetic system bcc iron,with applications to phonon calculations for different magnetic states,and molecular-dynamics simulations with fluctuating magnetic moments.

关键词： magnetic fluctuating states

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Machine learning-driven synthesis of TiZrNbHfTaC_(5) high-entropy carbide

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npj Computational Materials 2023年第1期9卷 2293-2303页

作者： alexander Ya.Pak Vadim Sotskov Arina A.Gumovskaya Yuliya Z.Vassilyeva Zhanar S.Bolatova Yulia A.Kvashnina Gennady Ya.Mamontov alexander V.Shapeev alexander G.Kvashnin National Research Tomsk Polytechnic University 30 Lenin AvenueTomsk 634050Russia Skolkovo Institute of Science and Technology Skolkovo Innovation CenterBolshoi Blv.30Building 1Moscow 121205Russia Pirogov Russian National Research Medical University 1 Ostrovityanova St.Moscow 117997Russia

Synthesis of high-entropy carbides(HEC)requires high temperatures that can be provided by electric arc plasma ***,the formation temperature of a single-phase sample remains ***,under some temperatures multi-phase structures can *** this work,we developed an approach for a controllable synthesis of HEC TiZrNbHfTaC_(5) based on theoretical and experimental *** used Canonical Monte Carlo(CMC)simulations with the machine learning interatomic potentials to determine the temperature conditions for the formation of single-phase and multi-phase *** full agreement with the theory,the single-phase sample,produced with electric arc discharge,was observed at 2000 *** 1200 K,the sample decomposed into(Ti-Nb-Ta)C,and a mixture of(Zr-Hf-Ta)C,(Zr-Nb-Hf)C,(Zr-Nb)C,and(Zr-Ta)*** results demonstrate the conditions for the formation of HEC and we anticipate that our approach can pave the way towards targeted synthesis of multicomponent materials.

关键词： carbide materials

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Inflammatory pseudotumors in the liver associated with influenza:A case report

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World Journal of Hepatology 2023年第10期15卷 1164-1169页

作者： Ankoor Patel alexander Chen alexander T Lalos Department of Medicine Rutgers-Robert Wood Johnson Medical SchoolNew BrunswickNJ 08901United States Department of Gastroenterology and Hepatology Rutgers-Robert Wood Johnson Medical SchoolNew BrunswickNJ 08901United States

BACKGROUND Inflammatory pseudotumor(IPT)is a rare and benign lesion that mimics malignancy and can develop in any part of the *** pathophysiology and etiology of these quasineoplastic lesions remain *** SUMMARY We report a case of a 65-year-old male who presented with fevers,night sweats,and unintentional weight loss following an influenza infection and was found to have multiple hepatic IPT’s following an extensive work *** Our case highlights the importance of considering hepatic IPT’s in the differential in a patient who presents with symptoms and imaging findings mimicking malignancy shortly following a viral infection.

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Interaction of Radiation and Turbulent Natural Convection:A Pseudo-Direct Numerical Study

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Advances in Applied Mathematics and Mechanics 2022年第6期14卷 1567-1586页

作者： alexander Nee Ali J.Chamkha Research and Educational Center of I.N.Butakov National Research Tomsk Polytechnic UniversityTomskRussia Faculty of Engineering Kuwait College of Science and TechnologyDoha DistrictKuwait

This paper presents a hybrid lattice Boltzmann solver for turbulent buoyancy-driven flow coupled with surface thermal *** two-relaxation time scheme for the Boltzmann equation combined with the implicit finite difference scheme for the energy equation is implemented to compute the heat transfer and fluid flow *** accuracy and robustness of the hybrid approach proposed in this study are assessed in terms of the numerical and experimental data of other *** performing the simulation,the Rayleigh number is ranged from 108 to 1010 whereas the surface emissivity is changed from zero to *** computations,it is found that the overall temperature of the cavity is increased as a result of enhancing the surface *** plumes are formed both at the isothermal and the thermally-insulated walls with the Ra109 and#*** the conditions under study,the overall heat transfer rate is raised by around 5%when taking into account the surface thermal radiation.

关键词： Pseudo-direct numerical simulation surface radiation hybrid lattice Boltzmann scheme turbulent natural convection.

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Tuning the Spatially Controlled Growth,Structural Self-Organizing and Cluster-Assembling of the Carbyne-Enriched Nano-Matrix during Ion-Assisted Pulse-Plasma Deposition

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Fluid Dynamics & Materials Processing 2022年第6期18卷 1763-1779页

作者： alexander Lukin Oğuz Gülseren Integrated Carbon Nano-Systems Lab Western-Caucasus Research CenterTuapse352808Russian Federation Department of Physics Bilkent UniversityÇankayaAnkara06800Turkey

Carbyne-enriched nanomaterials are of current interest in nanotechnology-related *** properties of these nanomaterials greatly depend on their production *** particular,structural self-organization and auto-synchronization of nanostructures are typical phenomena observed during the growth and heteroatom-doping of carbyne-enriched nanostructured metamaterials by the ion-assisted pulse-plasma deposition ***,fine tuning of these processes may be seen as the key step to the predictive designing of carbyneenriched nano-matrices with improved *** particular,we propose an innovative concept,connected with application of the vibrational-acoustic effects and based on universal Cymatics *** effects are used to induce vibration-assisted self-organized wave patterns together with the simultaneous manipulation of their properties through an electric *** between the inhomogeneous electric field distribution generated on the vibrating layer and the plasma ions serves as the additional energizing factor controlling the local pattern formation and self-organization of the nano-structures.

关键词： Carbyne-enriched nanomaterials ion assisted pulse plasma deposition carbon sp-chains stabilization of sp-hybridized carbon sp-encapsulating heteroatom-doping vibrational-acoustic activation vibrational patterns electromagnetic activation nanoscale self-organization standing surface acoustic waves nano-Cymatics predictive patterning

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