Materials physics and mechanics

RAR RUS 1-8 Aalto University Nefedov

Aalto, Finland

Effects of Electromagnetic Interaction in Periodic Arrays of Single-wall Metallic Carbon Nanotubes We demonstrate that periodic arrays of single-wall metallic carbon nanotubes (CNTs) exhibit electromagnetic wave properties which are strongly different that possessed by single CNTs. The distinctive feature of CNT arrays is a hyperbolic dispersion of electromagnetic waves, propagating in these structures. Electromagnetic interaction between carbon nanotubes leads to dramatic slowdown of eigenwaves in CNT arrays. carbon nanotube array slow waves hyperbolic dispersion hyperbolic media https://mpm.spbstu.ru/article/2012.20.1/ MPM_2012_13_1_P01.pdf

RAR RUS 9-21 Peter the Great St. Petersburg Polytechnic University Melker A.I.

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Krupina

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Kotov

St.Petersburg, Russia

Theory of Vibrations of Tetra-Atomic Symmetric Bent Molecules In this contribution we submit a theory of vibrations of a tetra-atomic symmetric bent molecule ABBA in cis-conformation. Compared to the previous calculations, where some approximations have been made, now we gave a more rigorous version. For the molecule studied we have calculated frequencies of all five vibrations. Among them three vibrations, ax1, ay1, and sy1, are normal or nearly normal. The longitudinal vibrations are of two types: (→← →←) and (→→ ←←). vibrations; tetra-atomic symmetric bent molecule calculated frequencies vibration classification normal (or nearly normal) vibrations: ax1 ay1 sy1 longitudinal vibrations of two types https://mpm.spbstu.ru/article/2012.20.2/ MPM_2012_13_1_P02.pdf

RAR RUS 22-36 Peter the Great St. Petersburg Polytechnic University Melker A.I.

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Lonch

St.Petersburg, Russia

Atomic and Electronic Structure of Mini-Fullerenes: from Four to Twenty It is customary to assume that fullerenes are the carbon molecules having a shape close to a spherical surface which can be composed of regular pentagons combined with regular hexagons. Earlier we developed a method for calculating electronic and atomic structure for such fullerenes. Now we suppose that the restriction on fullerenes construction only from pentagons and hexagons is unnecessary. In other words, we take the term "fullerene" in a broad sense to mean any shape inscribed into to a spherical surface which can be composed of carbon atoms, each atom having three nearest neighbors, whenever discussing hollow carbon clusters. In addition to this definition, we suppose that not only atoms but also shared electron pairs, forming covalent bonds, are located on one and the same sphere. From this it follows that the geometry of both the electronic structure as well as of the atomic structure of fullerenes can be most conveniently constructed and studied with the help of spherical geometry. We enlarged here the approach developed earlier for usual fullerenes. The procedure created reveals the hidden symmetry of the shared electron pairs located on the same sphere as that of carbon atoms. The most interesting result is that we have found structural isomers of some fullerenes which differed in their surface electronic density. fullerene in a broad sense shared electron pairs covalent bonds spherical geometry hidden symmetry structural isomers surface electronic density https://mpm.spbstu.ru/article/2012.20.3/ MPM_2012_13_1_P03.pdf

RAR RUS 37-47 Ural Branch of the Russian Academy of Sciences Mikheev

Izhevsk, Russia

Institute of Applied Mechanics, Ural Branch of the Russian Academy of Sciences Mogileva

Izhevsk, Russia

Institute of Applied Mechanics, Ural Branch of the Russian Academy of Sciences Mikheev

Izhevsk, Russia

Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences Kuznetsov

Novosibirsk, Russia

Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences Moseenkov

Novosibirsk, Russia

Diamagnetism Appearance of Onion-like Carbon Suspension by Laser Radiation The effect of nanosecond laser pulses (λ=1064 nm) on the optical properties of onion-like carbon (OLC) prepared by high-temperature vacuum annealing of detonation nanodiamond and dispersed in N,N-dimethylformamide (DMF) was studied. It is found that the interaction between laser pulses and OLC suspension resulted in the suspension bleaching in the interaction point. The bleached fraction of the suspension was pushed out from inhomogeneous magnetic field. The observed behavior could be explained by laser-stimulated chemical reactions between OLC and DMF, which led to the formation of a new substance with pronounced diamagnetic properties. Relying on the effect discovered, a model of magnetically controlled optical switch was proposed. diamagnetism onion-like suspension optical bleaching laser radiation https://mpm.spbstu.ru/article/2012.20.4/ MPM_2012_13_1_P04.pdf

RAR RUS 48-50 Tambov G.R. Derzhavin State University Fedorov

Tambov, Russia

Tambov G.R. Derzhavin State University Kuznetsov

Tambov, Russia

Tambov G.R. Derzhavin State University Boytsova

Tambov, Russia

Tambov G.R. Derzhavin State University Jakovlev

Tambov, Russia

Action of Laser Radiation on Crystals of Gallium Arsenide In this paper we investigated the mechanical and morphological characteristics of gallium arsenide single crystals after laser irradiation of their surface. laser radiation melt; laser inpigment point semiconductor https://mpm.spbstu.ru/article/2012.20.5/ MPM_2012_13_1_P05.pdf

RAR RUS 51-56 Tambov G.R. Derzhavin State University Fedorov

Tambov, Russia

Tambov G.R. Derzhavin State University Novikov

Tambov, Russia

Tambov G.R. Derzhavin State University Chivanov

Tambov, Russia

Mechanism and Model of Impulse Luminescence in AHC by the Action of β - Particles Stationary Flow We studied the impulse luminescence of AH crystals in the visible and ultra-short wavelengths under stationary flow beta-particles. We propose a mechanism and model of the luminescence. pulse luminescence luminescence AHC color centers spectrum of emission and transmission https://mpm.spbstu.ru/article/2012.20.6/ MPM_2012_13_1_P06.pdf

RAR RUS 57-63 Peter the Great St. Petersburg Polytechnic University Tolochko

St.Petersburg, Russia

Korean Institute of Machinery and Materials Choi

Korea

Aalto University Nasibulin

Finland

Institute of Silicate Chemistry, Russian Academy of Sciences Vasilyeva

St.Petersburg, Russia

Korean Institute of Machinery and Materials Lee

Korea

Korean Institute of Machinery and Materials Kim

Korea

Thermal Behavior of Iron Nanoparticles Synthesized by Chemical Vapor Condensation Iron nanoparticles were prepared by chemical vapor condensation (CVC) using iron pentacarbonyl, Fe(CO)5, as a precursor under inert Ar and He atmospheres in a flow reactor. Subsequently, the produced nanoparticles were heat-treated at different temperatures in air. The processes of the particle morphology and phase composition changes were studied. It was found that under the continuous thermal treatment the iron nanopowders were continuously transformed from oxide-coated iron via void magnetite to large hematite nanoparticles. It was shown that low temperature heat-treatment allowed to improve magnetic properties of the oxide-coated iron nanoparticles. iron nanoparticles thermal treatment magnetic properties https://mpm.spbstu.ru/article/2012.20.7/ MPM_2012_13_1_P07.pdf

RAR RUS 64-69 University of Warmia and Mazury in Olsztyn Kus

Olsztyn, Poland

University of Bialystok Breczko

Bialystok, Poland

Change in the Transformation Sequence due to Stress-Free Thermal Cycling of Ni-Ti Shape Memory Alloy The stress-free thermal cycling with help of a differential scanning calorimeter (DSC) is executed through the transformation range of a fully annealed Ni-Ti alloy sample, continuously observing the variations in the calorimetric profiles and related thermal parameters. The influence of two different cooling rates right after annealing on the transformation properties is extra and separately examined. It is found that as the thermal cycle number increases, the transformation sequence changes into a two-stage behaviour on cooling, and the first visible symptoms related to the appearance of intermediate R-phase occur after 10th full cycle. Apart from a progressive decrease of the critical temperatures, there is no DSC evidence for the two-stage reaction on heating within the whole thermal cycling test. As a result of the higher cooling rate after annealing, somewhat higher transformation temperatures are measured for the Ni-Ti alloy. Ni-Ti SMA stress-free thermal cycling DSC analysis https://mpm.spbstu.ru/article/2012.20.8/ MPM_2012_13_1_P08.pdf

RAR RUS 70-76 T-5749-2017 6602123579 0000-0002-2102-1076 Peter the Great St. Petersburg Polytechnic University Kodzhaspirov Georgij kodjaspirov@spbstu.ru

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Terentyev

St.Petersburg, Russia

Modeling the Dynamically Recrystallized Grain Size Evolution of a Superalloy The evolution of the UNS 6617 alloy microstructure during the hot deformation and the effect of hot deformation parameters on the grain structure and on the dynamic recrystallization were studied. A mathematical model which is capable to calculate the dynamically recrystallized austenite grain size of the alloy was built. dynamic recrystallization superalloy Zener-Hollomon parameter activation energy https://mpm.spbstu.ru/article/2012.20.9/ MPM_2012_13_1_P09.pdf

RAR RUS 77-84 Aalto University Nasibulina

Finland

Aalto University Anoshkin

Finland

Peter the Great St. Petersburg Polytechnic University Semencha

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Tolochko

St.Petersburg, Russia

Aalto University Malm

Finland

Aalto University Karppinen

Finland

Aalto University Nasibulin

Finland

Aalto University Kauppinen

St.Petersburg, Russia

Carbon Nanofiber/Clinker Hybrid Material as a Highly Efficient Modificator of Mortal Mechanical Properties Carbon nanofiber (CNF) / clinker hybrid material was prepared by a direct synthesis of CNFs on the surface of clinker particles in a fluidized bed reactor using acetylene and carbon dioxide gases at the temperature of 550°C. This allowed us to achieve a good dispersion of CNFs in a clinker matrix and to prepare strong mortar composite. Optimal concentration of the CNFs to enhance mechanical properties of the mortar was found to be around 0.4%, which led to more than 2.5-fold increase in the compressive strength. cement reinforcemen compressive strength synthesis https://mpm.spbstu.ru/article/2012.20.10/ MPM_2012_13_1_P10.pdf