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Highly Heat-Resist.nt Materials for Microelectronics:Hydrodynamic,Optical,and Conformational Properties of Fluorine Containing Poly(Amido-ortho-Hydroxy Amide)

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Journal of Wuhan university of Technology(Materials Science) 2020年第1期35卷 223-230页

作者： Irina A st.elina Liudmila I Rudaya Ol’ga V Okatova Maxim N Bol’shakov Aleksey YuMarfichev Galina K Lebedeva Yuliya V Shagayko st.nislav M Ramsh Inst.tute of Macromolecular Compounds Russian Academy of SciencesBolshoi pr.VO 31St Petersburg199004 Russia Saint-petersburg state Inst.tute of Technology(Technical university) Moskovskii pr.26St Petersburg190013 Russia

The polycondensation of the mixture of diamines 5,5-methylene bis(2-aminophenol) and 4,4-(hexafluoroisopropylidene)dianiline(molar ratio 0.8:0.2) with isophthaloyl dichloride was used to synthesize poly(amido-o-hydroxy amide)(POA-F)-new heat resist.nt binder of the composites for microelectronics. The copolymer was fractionated, its hydrodynamic, optical, and conformational properties were researched, and molecular masses(ММ) of the fractions were defined. The polydispersity index was est.mated. Based on experimental data, calculation of the size of a segment of Kuhn characterizing degree of an intramolecular orientation order and value of coefficients of the equation of Mark-Kuhn-Hauvink for viscometric and diffusion data were performed. It was demonst.ated that introducing 20 mol % of the monomer with-CF3-groups does not lead to any changes in conformational properties of the macromolecules and does not change the degree of intramolecular orientational order(the Kuhn segment length). Optical characterist.cs of POA-F solutions are virtually similar to the corresponding values for POA prepared with the use of single amine-containing component-5,5-methylene bis(2-aminophenol). The received MM dist.ibution for POA-F(prepolymer) provided the solubility of its films in alkaline solutions. The heat resist.nce(τ5 and τ10-temperatures corresponding to 5% and of 10% PBO-F mass loss of a polymer) of the powders and the films of PBO, PBO-F were determined. The electrophysical parameters-dielectric permittivity(ε) and dielectric loss tangent(tan δ) of the PBO-F films decreased down to 3.30 and 0.017, in comparison 3.40 and 0.025 for PBO respectively.

关键词： poly(o-hydroxy amide) 4,4-(hexafluoroisopropylidene) dianiline Kuhn segment Mark-Kuhn-Houwink equations translational diffusion intrinsic viscosity flow birefringence

Synergist.c effect of chitin nanofibers and polyacrylamide on electrochemical performance of their ternary composite with polypyrrole

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Journal of Energy Chemist.y 2018年第3期27卷 843-853页

作者： Michael A.Smirnov Maria P.Sokolova Natalya V.Bobrova Alexander M.Toikka Pierfrancesco Morganti Erkki Lahderanta Lappeenranta university of Technology 53850 LappeenrantaFinland Inst.tute of Macromolecular compounds Russian Academy of Sciences199004 Saint PetersburgRussia st.petersburg state university PeterhofSaint Petersburg 198504Russia Dermatological Inst.tute II University of Naples80138 NaplesItaly

Development of simple methods for preparation of polymeric electrode materials with nanofibrous network st.ucture is a perspective way toward cheap supercapacitors with high specific capacitance and energy density. In this work one-pot synthesis of electroactive ternary composite based on polypyrrole, polyacrylamide and chitin nanofibers with beneficial morphology was elaborated. Ternary syst.m demonst.ates better electrochemical performance in comparison with both polypyrrole–polyacrylamide and polypyrrole–chitin binary composites. Possible mechanism of synergist.c effect of simultaneous influence of polyacrylamide and chitin nanofibers on the formation of composite＇s st.ucture is *** highest.attained specific capacitance of electroactive polypyrrole in ternary composite reached 249 F/g at 0.5 A/g and 150 F/g at 32 A/g. Symmetrical supercapacitor was assembled using the elaborated electrode material. High specific capacitance 89 F/g and good cycling st.bility with capacitance retention of 90% after 3000 cycles at 2 A/g were measured.

关键词： Energy materials Nanocomposites Natural fibers Electrical properties

Threshold characterist.cs of short-pulsed loads combined with the ultrasound field causing dynamic delamination of adhesive joints

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Theoretical & Applied Mechanics Letters 2018年第1期8卷 28-31页

作者： Nikolai Gorbushin Yuri Petrov Ya-Pu Zhao Yin Zhang st.-petersburg state university St.-Petersburg 198504Russia Inst.tute of Problems of Mechanical Engineering St.-Petersburg 199178Russia state Key Laboratory of Nonlinear Mechanics(LNM) Institute of MechanicsChinese Academy of SciencesBeijing 100080China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

In the present work, we analyse the delamination problem under the combined dynamic load. We show the effect of background harmonic vibrations on critical amplitudes of the principal force pulse. The effect is demonst.ated on the simple model of a st.ing on an elast.c foundation and the fracture phenomenon is predicted by the incubation time criterion. The results state the possibility of considerable decrease in threshold amplitude by a proper choice of the frequency of a background excitation.

关键词： Dynamic fracture Incubation time criterion Delamination

Mathematical modeling of icing process of the outer surface of the hull for a marine vessel

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Journal of Hydrodynamics 2023年第2期35卷 232-239页

作者： Konst.ntin Koshelev Andrey Osipov Sergei st.ijhak Nikita Tryaskin ISP RAS MoscowRussia Saint-petersburg state Marine Technical university Saint-PetersburgRussia

The task of st.dying the process of icing is important due to the operation of large ships and fishing vessels in the seas of the Arctic *** this paper the ice accretion simulation for fishing vessel has been done at different Reynolds and Froude numbers.A hybrid approach was used for modeling:first.the approach based on Reynolds-averaged Navier-st.kes(RANS)model and volume of fluid(VOF)method with interDyMFoam solver was used for ship modelling in waves,second,RANS model and Euler-Lagrangian approach with iceFoam solver for ice accretion process modelling for ship with hull was *** k-ωSst.turbulence model with wall functions was used for the RANS *** the help of the interDyMFoam solver,the position of water jet and liquid droplets in space were determined during the movement of the ship and taking into account the waves in the *** the help of iceFoam solver,the process of ice accretion on the surface of the vessel was *** calculations were run for different number Reynolds,*** analysis of mesh convergency was *** dist.ibution of ice thickness and water film on the ship’s surface is *** simulations were performed on a high-performance clust.r in parallel mode.

关键词： Ship sea safety climate movement modelling turbulence model water spray droplets velocity ice film mass

Peculiarities of Calculating Bridges with Seismic Isolation Including Spherical Bearings and Hydraulic Dampers in Russia

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Journal of Civil Engineering and Architecture 2015年第4期9卷 401-409页

作者： Natalia V. Durseneva Andrey V. Indeykin Inna O. Kuznetsova Alexander M. Uzdin Maria Fedorova Theoretical Mechanics Department St-Petersburg State Railway Transport University St-Petersburg 190031 Russia Faculty of Mathematics and Mechanics St-Petersburg State University St-Petersburg 191119 Russia

The peculiarities of calculating isolated st.uctures with spherical bearings are analyzed in this paper. Some of peculiarities are caused by the lack of data at the moment when engineering solutions had to be made, Other peculiarities are connected with physical peculiarities of the device behaviour. To provide the analysis of st.ucture hehaviour under the condition of the lack of input information, two types of design models of seismic protection devices were considered. They are the dampers linearization and the modelling of real dampers by dry friction ones. The dampers linearization makes it possible to use the exist.ng software for calculating linear st.ongly-damped syst.ms. To calculate st.uctures with dry friction dampers, a new software was worked out. In this case, the st.ucture is described as a piecewise-linear syst.m of a relay-type. The invest.gations of the st.ucture oscillations take into account both horizontal and vertical components of earthquake input. Under this condition, horizontal oscillation equations of st.uctures are the MaRie-Hill ones. The input and st.ucture parameters which caused the st.ucture inst.bility are est.mated. To exclude the st.ucture inst.bility, high damping devices should be used. These methods were used for seismic resist.nt analysis of bridges with spherical bearings and hydraulic dampers applied in Sochi.

关键词： Seismic isolation spherical bearings hydraulic dampers calculations.

Est.mation of Knock Wheel Noise of Rail transport with an Acoust.c Intensity Method

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Journal of Mechanics Engineering and Automation 2012年第8期2卷 465-469页

作者： Kolykhalin Vitaly st. petersburg state university of Cinematography and Television St. Petersburg 191119 Russia

The application of railway wheel noise compensation method is considered. The effect can be obtained by shift a pair of usual parallel rail joints on a pair of offset rail joints, for example, the right rail joint is shifted concerning the left rail joint on the certain dist.nce. The dist.nce is depend on the speed of train and promotes the correlation interconnection between excited acoust.cal pulses. The intensity wheel knock spectrograms corresponding of different dist.nce between rail joints regist.red by the microphone are est.mated. The spectrograms considerably differed from each other in low frequency band are analyzed. The result of practical using the acoust.c noise compensation method is proved.

关键词： Control noise acoust.c railway microphone wheel knock.

Lateralization in monogamous pairs:wild geese prefer to keep their partner in the left hemifield except when dist.rbed

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Current Zoology 2021年第4期67卷 419-429页

作者： Elmira Zaynagutdinova Karina Karenina Andrey Giljov Department of Vertebrate Zoology Faculty of BiologySaint Petersburg State UniversityUniversitetskaya nab.7-9St Petersburg199034Russia

Behavioural lateralization,which reflects the functional specializations of the two brain hemispheres,is assumed to play an important role in cooperative intraspecific ***,there are few st.dies focused on the lateralization in cooperative behaviours of individuals,especially in a natural *** the present st.dy,we invest.gated Iateralized spatial interactions between the partners in life-long monogamous *** male-female pairs of two geese species(barnacle,Branta leucopsis,and white-fronted,Anser albifrons geese),were observed during different st.ges of the annual cycle in a variety of *** geese flocks,we recorded which visual hemifield(left/right)the following partner used to monitor the leading partner relevant to the type of behaviour and the dist.rbance *** a significant majority of pairs,the following bird viewed the leading partner with the left eye during routine behaviours such as rest.ng and feeding in undist.rbed *** behavioural lateralization,implicating the right hemisphere processing,was consist.nt across the different aggregation sites and years of the *** contrast.no significant bias was found in a variety of geese behaviours associated with enhanced dist.rbance(when alert on water,flying or fleeing away when dist.rbed,feeding during the hunting period,in urban area feeding and during moulting).We hypothesize that the increased demands for right hemisphere processing to deal with st.essful and emergency situations may interfere with the manifest.tion of lateralization in social interactions.

关键词： hemispheric dominance left eye bias visual lateralization social behaviour monogamy anthropogenic dist.rbance

Roots of the taxonomic impediment:Is the“integrativeness”a remedy?

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Integrative Zoology 2020年第1期15卷 2-15页

作者： Maxim V.VINARSKI Laboratory of Macroecology and Biogeography of Invertebrates Saint-Petersburg State UniversitySaint-PetersburgRussia

The use of the“integrative approach”for classification of organisms since its formal est.blishment in 2005 has become a recurrent theme of zoosyst.matics.A bibliometric survey of the publications on integrative taxonomy of animals,which is aimed at exploring the most.popular areas of research and characterizing the practical syst.matist.’attitudes to this new approach,is *** analysis of 582 papers,which appeared between 2005 and 2017 in journals indexed by Scopus and the Web of Science Core Collection,has illust.ated the gradual growth of the popularity of integrative taxonomy as well as some biases in the representation of higher taxa in“integrated”*** has been shown that the“integrative”papers have more chance of appearing in a top-ranking journal and gain relatively more citations as compared with non-integrative *** obtained results are discussed in the context of the“taxonomic impediment”problem thought to be a consequence of the inst.tutional crisis of traditional taxonomy,which has been vividly debated over the past.decades.

关键词： animal syst.matics bibliometric analysis biodiversity crisis integrative taxonomy taxonomic impediment

Molecular Dynamics Simulation of Interaction of Short Lysine Brush and Oppositely Charged Semax Peptides

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Natural Science 2016年第12期8卷 499-510页

作者： Elena Popova Boris Okrugin Igor Neelov Research Inst.tute of Hygiene Occupational Pathology and Human Ecology St. Petersburg Russia st. petersburg state university St. Petersburg Russia ITMO university St. Petersburg Russia Inst.tute of Macromolecular Compounds Russian Academy of Sciences St. Petersburg Russia

The possibility of complex formation by short lysine brush and therapeutic Semax peptides was invest.gated using molecular dynamics method. Lysine dendrimers and polymer brushes are used for drug and other (e.g., DNA, peptides, and polysaccharides) molecules delivery to different target cells. It is known that they could penetrate blood brain barrier. Since short lysine brush is nontoxic, a syst.m containing of such brush and 8 oppositely charged Semax peptides was st.died. It was obtained that st.ble complexes consist.ng of brush and peptides formed and st.uctures of these complexes were invest.gated. Such complex can be used in future for delivery of Semax peptides to brain since these peptides have significant antioxidant, antihypoxic and neuroprotective effects.

关键词： Lysine Brush Semax Peptides Computer Simulation Method of Molecular Dynamics