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Detection of ground ice using ground penetrating radar method

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Research in Cold and Arid Regions 2015年第5期7卷 541-546页

作者： Gennady M.Stoyanovich viktor v.pupatenko Yury A.Sukhobok Transport Construction Institute Department of Railway Track and Railway Engineering Far Eastern State Transport University

The paper presents the results of a ground penetrating radar （GPR） application for the detection of ground ice. We com- bined a reflection traveltime curves analysis with a frequency spectrogram analysis. We found special anomalies at specific traces in the traveltime curves and ground boundaries analysis, and obtained a ground model for subsurface structure which allows the ground ice layer to be identified and delineated.

关键词： ground penetrating radar ground ice common-offset reflection survey wide angle reflection and refractionmethod

Olefin Polymerization Behavior of Titanium(Iv) Complexes with Fluorinated and Non-fluorinated Aliphatic Phenoxyimine Ligands

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Chinese Journal of Polymer Science 2024年第1期42卷 52-62,I0007页

作者： vladislav A.Tuskaev Kasim F.Magomedov Svetlana Ch.Gagieva Dmitry A.Kurmaev Yulia v.Nelyubina Evgenii K.Golubev Maria D.Evseeva viktor G.vasil'ev Galina G.Nikiforova Mikhail I.Buzin vyacheslav S.Bogdanov Boris M.Bulychev Department of Chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of Synthetic Polymer Materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been *** molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction *** complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis *** of activators(MMAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)Mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was *** Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/Mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented *** rheological characteristics of a polymer melt have been *** absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film *** activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

关键词： FI catalysts Titanium(Iv) (Co)polymerization Al/Mg co-catalyst Ultra-high molecular weight polyethylene

Mechanism of the Initial Stage of Thermal Decomposition of Nitroguanidine

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火炸药学报 2023年第1期46卷 31-40页

作者： Boris E.Krisyuk Danila A.Markin Timofey M.Sypko viktor v.Zakharov Nikita v.Chukanov Boris L.Korsunskiy Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry Russian Academy of Sciences142432prosp.Academician Semenov1ChernogolovkaMoscow RegionRussia Plekhanov Russian University of Economics Department of Chemistry and Physics36 Stremyanny laneMoscow 117997Russia Lomonosov Moscow State University Faculty of Fundamental Physical and Chemical engineeringGSP-11 Leninskie Goryp.51Moscow 119991Russia N.N.Semenov Federal Research Center for Chemical Physics Russian Academy of Science 4 Kosygina StreetBuilding 1Moscow 119991Russia

A theoretical and experimental study of the thermal decomposition of nitroguanidine(NQ) has been carried out. various thermolysis channels were studied by quantum chemistry methods at the CCSD(or DLPNO-CCSD) level using the aug-cc-pvDZ basis set. It is shown that the lowest activation enthalpies(170-180kJ/mol) are characteristic of the reactions of NO2abstraction from the initial NQ and the reaction channel with the transfer of oxygen from the nitro group to carbon in the limiting stage. Additionally, the thermolysis of NQ was studied experimentally in a nonisothermal mode with heating rates from 1 to 10K/min. In these experiments, the weight loss of the sample, thermal effects, and mass spectra of the products were recorded. An analysis of the experimental data confirmed the results of a theoretical study of the mechanism of thermal decomposition of NQ. The main thermolysis products are N2O, HNCO, NH3, and NO2, which fully corresponds to quantum chemical calculations.

关键词： primary thermolysis steps quantum-chemical calculation mass spectrometry DSC TG

Structure,magnetic and adsorption properties of novel FePt/h-BN heteromaterials

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Nano Research 2023年第1期16卷 1473-1481页

作者： Anton S.Konopatsky vladislava v.Kalinina Alena S.Savchenko Denis.v.Leybo Ekaterina v.Sukhanova viktor S.Baidyshev Zakhar I.Popov Andrey v.Bondarev Josef Polčák Dmitry v.Shtansky National University of Science and Technology(MISIS) Leninskiy prospect 4Moscow119049Russia Emanuel Institute of Biochemical Physics RAS Kosygina 4Moscow119334Russia Katanov Khakas State University 90 Lenin pr.655017 AbakanRussia Plekhanov Russian University of Economics 36 Stremyanny per.Moscow 117997Russia Department of Control Engineering Faculty of Electrical EngineeringCzech Technical University in PragueTechnicka 2Prague 16627Czech Republic CEITEC-Central European Institute of Technology Brno University of TechnologyPurkyňova 123Brno 61200 BrnoCzech Republic

Nanomaterials with high specific surface area and high absorption capacity are attracting increased interest aimed at imparting the desired magnetic *** work is devoted to the study of the effect of heat treatment in a hydrogen atmosphere on the microstructure,adsorption and magnetic properties of heterogeneous FePt/h-BN *** via the polyol process,FePt nanoparticles(NPs)had a sizever the surface of hexagonal boron nitride(h-BN)*** temperature-activated fcc→fct phase transformation in ultrafine FePt NPs has been well *** NPs act as active centers dissociating H2 molecules and transfer adsorbed hydrogen atoms to the *** functional theory(DFT)calculations also indicate that the h-BN substrate can absorb hydrogen adsorbed on the FePt *** hydrogen circulation in the FePt/h-BN system promoted the fcc→fct phase transformation and allowed to control the magnetic ***/h-BN nanomaterials also exhibited a high adsorption capacity with respect to various organic dyes.

关键词： FePt/h-BN nanomaterials polyol synthesis phase transformations magnetic properties adsorption

Trapped on the Roof of the World:taxonomic diversity and evolutionary patterns of Tibetan Plateau endemic freshwater snails(Gastropoda:Lymnaeidae:Tibetoradix)

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Integrative Zoology 2022年第5期17卷 825-848页

作者： Maxim v.vINARSKI Parm viktor vON OHEIMB Olga v.AKSENOvA Mikhail Yu.GOFAROv Alexander v.KONDAKOv Ivan O.NEKHAEv Ivan N.BOLOTOv Laboratory of Macroecology and Biogeography Saint-Petersburg State UniversitySaint-PetersburgRussia Museum für Naturkunde-Leibniz Institute for Evolution and Biodiversity Science BerlinGermany N.Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences ArkhangelskRussia Department of Applied Ecology Saint-Petersburg State UniversitySaint-PetersburgRussia Northern(Arctic)Federal University ArkhangelskRussia

The high-elevation Tibetan Plateau(western China)is inhabited by a unique,though not particularly species-rich,community of *** explored the species content and evolutionary history of the Tibetan Plateau endemic freshwater snail genus *** relationships within the genus were reconstructed based on available sequence *** used a single-rate Poisson Tree Processes approach for species delimitation and compared putative species-level clades with already described *** found that the genus consists of at least 6 species,of which we described 4 as new to *** and soft body morphology was examined and the radula in Tibetoradix was described for theﬁrst *** on ourﬁndings,the diversiﬁcation of the genus did not result in a prominent morphological differentiation and a number of species can be regarded as morphologically *** species found in different drainage areas indicate relatively good passive dispersal abilities of the *** allopatric distribution of the species could result from competitive exclusion between *** absence of Tibetoradix *** the Tibetan Plateau could be explained by a scenario of an“evolutionary trap”,where adaptations to high elevation conditions prevented the taxa from a successful colonization of lower elevations.

关键词： biogeography High Asia molecular phylogenetics morphology species delimitation

Performance of two complementary machine-learned potentials in modelling chemically complex systems

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npj Computational Materials 2023年第1期9卷 1008-1022页

作者： Konstantin Gubaev viktor Zaverkin Prashanth Srinivasan Andrew Ian Duff Johannes Kästner Blazej Grabowski Institute for Materials Science University of StuttgartPfaffenwaldring 5570569 StuttgartGermany Institute for Theoretical Chemistry University of StuttgartPfaffenwaldring 5570569 StuttgartGermany Scientific Computing Department STFC Daresbury LaboratoryWarrington WA44ADUK Present address:NEC Laboratories Europe GmbH Kurfürsten-Anlage 3669115 HeidelbergGermany

Chemically complex multicomponent alloys possess exceptional properties derived from an inexhaustible compositional *** complexity however makes interatomic potential development *** explore two complementary machine-learned potentials—the moment tensor potential(MTP)and the Gaussian moment neural network(GM-NN)—in simultaneously describing configurational and vibrational degrees of freedom in the Ta-v-Cr-W alloy *** models are equally accurate with excellent performance evaluated against *** achieve root-mean-square-errors(RMSEs)in energies of less than a few mev/atom across 0 K ordered and high-temperature disordered configurations included in the *** for compositions not in training,relative energy RMSEs at high temperatures are within a few mev/***-temperature molecular dynamics forces have similarly small RMSEs of about 0.15 ev/Åfor the disordered quaternary included in,and ternaries not part of *** achieve faster convergence with training size;GM-NNs are faster in *** learning is partially beneficial and should be complemented with conventional human-based training set generation.

关键词： alloy faster complex

FeH_(x)的稳定性以及氢在地球核-幔边界的传输

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Science Bulletin 2023年第14期68卷 1567-1573,M0004页

作者：何宇 Duck Young Kim viktor v.Struzhkin Zachary M.Geballe vitali Prakapenka 毛河光 Key Laboratory of High-Temperature and High-Pressure Study of the Earth’s Interior Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Center for High Pressure Science and Technology Advanced Research Shanghai 201203China Division of Advanced Nuclear Engineering Pohang University of Science and TechnologyPohang 37673Republic of Korea Geophysical Laboratory Carnegie InstitutionWashington DC 20015USA Center for Advanced Radiation Sources University of ChicagoChicago IL 60637USA

地球内部水和铁的反应可以生成铁-氢合金.研究铁-氢合金可以增进对地球内部氢传输的认知.我们通过高压实验和第一性原理计算的方法,对高温高压下具有面心立方结构(fcc)FeH_(x)(x≤1)的相稳定性、密度、氢的输运性质和熔点进行了系统研究... 详细信息

地球内部水和铁的反应可以生成铁-氢合金.研究铁-氢合金可以增进对地球内部氢传输的认知.我们通过高压实验和第一性原理计算的方法,对高温高压下具有面心立方结构(fcc)FeH_(x)(x≤1)的相稳定性、密度、氢的输运性质和熔点进行了系统研究,证实了FeH_(x)在165 GPa时的稳定性.通过高温的分子动力学模拟,发现FeH_(x)在下地幔温压下转变为超离子态.在超离子态FeH_(x)中,氢离子快速扩散表现出类似流体的性质,扩散系数高达3.710^(-4)cm~2s^(-1).与超离子态冰类似,氢离子的快速扩散可以导致体系的熵增,使其的熔化温度增加.FeH_(x)可以将氢从地幔传输到外地核,使得外核成为H的潜在储库,并在核-幔边界上方留下了富氧的块状结构.

关键词：离子态第一性原理计算氢离子相稳定性地球内部熔化温度高压实验分子动力学模拟

Multiscale wood micromechanics and size effects study via nanoindentation

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生物质资源与工程(英文) 2023年第3期8卷 246-264页

作者： Yuri I.Golovin Alexander A.Gusev Dmitry Yu.Golovin Sergey M.Matveev Alexander I.Tyrin Alexander A.Samodurov viktor v.Korenkov Inna A.vasyukova Maria A.Yunack Institute“Nanotechnology and Nanomaterials” G.R.Derzhavin Tambov State University392000 TambovRussia Department of Chemical Enzymology School of ChemistryLomonosov Moscow State University119991 MoscowRussia Research and Educational Center«Sustainable Development of the Forest Complex» Voronezh State Forestry University Named after G.F.Morozov394087 VoronezhRussia Department of Functional Nanosystems and High-Temperature Materials National University of Science and Technology“MISIS”119991 MoscowRussia

Wood as a material is a natural composite with a complex hierarchically arranged *** scale levels of wood structure contribute to its macroscopic mechanical *** nature of such characteristics and deformation modes differs radically at different scale *** macroscopic properties are well studied,and the relevant information can be easily found in the ***,the knowledge of the deformation mechanisms at the mesoscopic level corresponding to the cellular structure of early and late wood layers of annual growth rings is *** hinders building the comprehensive multiscale model of how wood mechanical properties are *** paper described the results of scanning of mechanical properties of softwood and hardwood samples,such as common pine,small-leaf lime,and pedunculate oak,by means of nanoindentation(NI).The NI technique allows varying the size of deformed region within a wide range by altering maximal load(P max)applied to the indenter so that one can re-peatedly and non-destructively test wood structural components at different scale levels on the same sample without changing the technique or *** was discovered that the effective microhardness(H eff)and Young’s modulus(E eff)decreased manifold with P max growing from 0.2 to 2000 *** drop in H effwas observed when the locally deformed region grew,and re-sulting from P max increase generally follows the rule similar to the Hall-Petch relation for yield stress,strength,and hardness initially established for metals and alloys,though obviously in those cases the underlying internal mechanisms are quite *** nature and micromechanisms of such size effect(SE)in wood revealed using NI were discussed in this *** P maxvich indenter was much smaller than the cell wall ***,in this case,NI measured the internal mechanical properties of the cell wall material as long as free boundaries impact

关键词： Nano/microhardness Scanning nanoindentation Annual growth ring Early and late wood Dendrochronology

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